xref: /illumos-gate/usr/src/uts/common/fs/zfs/zio.c (revision cd1c8b85)
1fa9e4066Sahrens /*
2fa9e4066Sahrens  * CDDL HEADER START
3fa9e4066Sahrens  *
4fa9e4066Sahrens  * The contents of this file are subject to the terms of the
5ea8dc4b6Seschrock  * Common Development and Distribution License (the "License").
6ea8dc4b6Seschrock  * You may not use this file except in compliance with the License.
7fa9e4066Sahrens  *
8fa9e4066Sahrens  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9fa9e4066Sahrens  * or http://www.opensolaris.org/os/licensing.
10fa9e4066Sahrens  * See the License for the specific language governing permissions
11fa9e4066Sahrens  * and limitations under the License.
12fa9e4066Sahrens  *
13fa9e4066Sahrens  * When distributing Covered Code, include this CDDL HEADER in each
14fa9e4066Sahrens  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15fa9e4066Sahrens  * If applicable, add the following below this CDDL HEADER, with the
16fa9e4066Sahrens  * fields enclosed by brackets "[]" replaced with your own identifying
17fa9e4066Sahrens  * information: Portions Copyright [yyyy] [name of copyright owner]
18fa9e4066Sahrens  *
19fa9e4066Sahrens  * CDDL HEADER END
20fa9e4066Sahrens  */
21fa9e4066Sahrens /*
223f9d6ad7SLin Ling  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23840345f6SGeorge Wilson  * Copyright (c) 2012 by Delphix. All rights reserved.
245aeb9474SGarrett D'Amore  * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved.
25fa9e4066Sahrens  */
26fa9e4066Sahrens 
27fa9e4066Sahrens #include <sys/zfs_context.h>
28ea8dc4b6Seschrock #include <sys/fm/fs/zfs.h>
29fa9e4066Sahrens #include <sys/spa.h>
30fa9e4066Sahrens #include <sys/txg.h>
31fa9e4066Sahrens #include <sys/spa_impl.h>
32fa9e4066Sahrens #include <sys/vdev_impl.h>
33fa9e4066Sahrens #include <sys/zio_impl.h>
34fa9e4066Sahrens #include <sys/zio_compress.h>
35fa9e4066Sahrens #include <sys/zio_checksum.h>
36b24ab676SJeff Bonwick #include <sys/dmu_objset.h>
37b24ab676SJeff Bonwick #include <sys/arc.h>
38b24ab676SJeff Bonwick #include <sys/ddt.h>
39fa9e4066Sahrens 
40fa9e4066Sahrens /*
41fa9e4066Sahrens  * ==========================================================================
42fa9e4066Sahrens  * I/O priority table
43fa9e4066Sahrens  * ==========================================================================
44fa9e4066Sahrens  */
45fa9e4066Sahrens uint8_t zio_priority_table[ZIO_PRIORITY_TABLE_SIZE] = {
46fa9e4066Sahrens 	0,	/* ZIO_PRIORITY_NOW		*/
47fa9e4066Sahrens 	0,	/* ZIO_PRIORITY_SYNC_READ	*/
48fa9e4066Sahrens 	0,	/* ZIO_PRIORITY_SYNC_WRITE	*/
49fa9e4066Sahrens 	0,	/* ZIO_PRIORITY_LOG_WRITE	*/
5080eb36f2SGeorge Wilson 	1,	/* ZIO_PRIORITY_CACHE_FILL	*/
5180eb36f2SGeorge Wilson 	1,	/* ZIO_PRIORITY_AGG		*/
5280eb36f2SGeorge Wilson 	4,	/* ZIO_PRIORITY_FREE		*/
5380eb36f2SGeorge Wilson 	4,	/* ZIO_PRIORITY_ASYNC_WRITE	*/
5480eb36f2SGeorge Wilson 	6,	/* ZIO_PRIORITY_ASYNC_READ	*/
55fa9e4066Sahrens 	10,	/* ZIO_PRIORITY_RESILVER	*/
56fa9e4066Sahrens 	20,	/* ZIO_PRIORITY_SCRUB		*/
57c7cd2421SGeorge Wilson 	2,	/* ZIO_PRIORITY_DDT_PREFETCH	*/
58fa9e4066Sahrens };
59fa9e4066Sahrens 
60fa9e4066Sahrens /*
61fa9e4066Sahrens  * ==========================================================================
62fa9e4066Sahrens  * I/O type descriptions
63fa9e4066Sahrens  * ==========================================================================
64fa9e4066Sahrens  */
65fa9e4066Sahrens char *zio_type_name[ZIO_TYPES] = {
6680eb36f2SGeorge Wilson 	"zio_null", "zio_read", "zio_write", "zio_free", "zio_claim",
6780eb36f2SGeorge Wilson 	"zio_ioctl"
6880eb36f2SGeorge Wilson };
69fa9e4066Sahrens 
70fa9e4066Sahrens /*
71fa9e4066Sahrens  * ==========================================================================
72fa9e4066Sahrens  * I/O kmem caches
73fa9e4066Sahrens  * ==========================================================================
74fa9e4066Sahrens  */
75ccae0b50Seschrock kmem_cache_t *zio_cache;
76a3f829aeSBill Moore kmem_cache_t *zio_link_cache;
77fa9e4066Sahrens kmem_cache_t *zio_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
78ad23a2dbSjohansen kmem_cache_t *zio_data_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
79ad23a2dbSjohansen 
80ad23a2dbSjohansen #ifdef _KERNEL
81ad23a2dbSjohansen extern vmem_t *zio_alloc_arena;
82ad23a2dbSjohansen #endif
8309c9d376SGeorge Wilson extern int zfs_mg_alloc_failures;
84fa9e4066Sahrens 
850a4e9518Sgw /*
86e14bb325SJeff Bonwick  * An allocating zio is one that either currently has the DVA allocate
87e14bb325SJeff Bonwick  * stage set or will have it later in its lifetime.
880a4e9518Sgw  */
89b24ab676SJeff Bonwick #define	IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE)
90b24ab676SJeff Bonwick 
9135a5a358SJonathan Adams boolean_t	zio_requeue_io_start_cut_in_line = B_TRUE;
9235a5a358SJonathan Adams 
93b24ab676SJeff Bonwick #ifdef ZFS_DEBUG
94b24ab676SJeff Bonwick int zio_buf_debug_limit = 16384;
95b24ab676SJeff Bonwick #else
96b24ab676SJeff Bonwick int zio_buf_debug_limit = 0;
97b24ab676SJeff Bonwick #endif
980a4e9518Sgw 
99fa9e4066Sahrens void
100fa9e4066Sahrens zio_init(void)
101fa9e4066Sahrens {
102fa9e4066Sahrens 	size_t c;
103ad23a2dbSjohansen 	vmem_t *data_alloc_arena = NULL;
104ad23a2dbSjohansen 
105ad23a2dbSjohansen #ifdef _KERNEL
106ad23a2dbSjohansen 	data_alloc_arena = zio_alloc_arena;
107ad23a2dbSjohansen #endif
108a3f829aeSBill Moore 	zio_cache = kmem_cache_create("zio_cache",
109a3f829aeSBill Moore 	    sizeof (zio_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
110a3f829aeSBill Moore 	zio_link_cache = kmem_cache_create("zio_link_cache",
111a3f829aeSBill Moore 	    sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
112ccae0b50Seschrock 
113fa9e4066Sahrens 	/*
114fa9e4066Sahrens 	 * For small buffers, we want a cache for each multiple of
115fa9e4066Sahrens 	 * SPA_MINBLOCKSIZE.  For medium-size buffers, we want a cache
116fa9e4066Sahrens 	 * for each quarter-power of 2.  For large buffers, we want
117fa9e4066Sahrens 	 * a cache for each multiple of PAGESIZE.
118fa9e4066Sahrens 	 */
119fa9e4066Sahrens 	for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) {
120fa9e4066Sahrens 		size_t size = (c + 1) << SPA_MINBLOCKSHIFT;
121fa9e4066Sahrens 		size_t p2 = size;
122fa9e4066Sahrens 		size_t align = 0;
123e291592aSJonathan Adams 		size_t cflags = (size > zio_buf_debug_limit) ? KMC_NODEBUG : 0;
124fa9e4066Sahrens 
125fa9e4066Sahrens 		while (p2 & (p2 - 1))
126fa9e4066Sahrens 			p2 &= p2 - 1;
127fa9e4066Sahrens 
128*cd1c8b85SMatthew Ahrens #ifndef _KERNEL
129*cd1c8b85SMatthew Ahrens 		/*
130*cd1c8b85SMatthew Ahrens 		 * If we are using watchpoints, put each buffer on its own page,
131*cd1c8b85SMatthew Ahrens 		 * to eliminate the performance overhead of trapping to the
132*cd1c8b85SMatthew Ahrens 		 * kernel when modifying a non-watched buffer that shares the
133*cd1c8b85SMatthew Ahrens 		 * page with a watched buffer.
134*cd1c8b85SMatthew Ahrens 		 */
135*cd1c8b85SMatthew Ahrens 		if (arc_watch && !IS_P2ALIGNED(size, PAGESIZE))
136*cd1c8b85SMatthew Ahrens 			continue;
137*cd1c8b85SMatthew Ahrens #endif
138fa9e4066Sahrens 		if (size <= 4 * SPA_MINBLOCKSIZE) {
139fa9e4066Sahrens 			align = SPA_MINBLOCKSIZE;
140*cd1c8b85SMatthew Ahrens 		} else if (IS_P2ALIGNED(size, PAGESIZE)) {
141fa9e4066Sahrens 			align = PAGESIZE;
142*cd1c8b85SMatthew Ahrens 		} else if (IS_P2ALIGNED(size, p2 >> 2)) {
143fa9e4066Sahrens 			align = p2 >> 2;
144fa9e4066Sahrens 		}
145fa9e4066Sahrens 
146fa9e4066Sahrens 		if (align != 0) {
147ad23a2dbSjohansen 			char name[36];
1485ad82045Snd 			(void) sprintf(name, "zio_buf_%lu", (ulong_t)size);
149fa9e4066Sahrens 			zio_buf_cache[c] = kmem_cache_create(name, size,
150e291592aSJonathan Adams 			    align, NULL, NULL, NULL, NULL, NULL, cflags);
151ad23a2dbSjohansen 
152e291592aSJonathan Adams 			/*
153e291592aSJonathan Adams 			 * Since zio_data bufs do not appear in crash dumps, we
154e291592aSJonathan Adams 			 * pass KMC_NOTOUCH so that no allocator metadata is
155e291592aSJonathan Adams 			 * stored with the buffers.
156e291592aSJonathan Adams 			 */
157ad23a2dbSjohansen 			(void) sprintf(name, "zio_data_buf_%lu", (ulong_t)size);
158ad23a2dbSjohansen 			zio_data_buf_cache[c] = kmem_cache_create(name, size,
159ad23a2dbSjohansen 			    align, NULL, NULL, NULL, NULL, data_alloc_arena,
160e291592aSJonathan Adams 			    cflags | KMC_NOTOUCH);
161fa9e4066Sahrens 		}
162fa9e4066Sahrens 	}
163fa9e4066Sahrens 
164fa9e4066Sahrens 	while (--c != 0) {
165fa9e4066Sahrens 		ASSERT(zio_buf_cache[c] != NULL);
166fa9e4066Sahrens 		if (zio_buf_cache[c - 1] == NULL)
167fa9e4066Sahrens 			zio_buf_cache[c - 1] = zio_buf_cache[c];
168ad23a2dbSjohansen 
169ad23a2dbSjohansen 		ASSERT(zio_data_buf_cache[c] != NULL);
170ad23a2dbSjohansen 		if (zio_data_buf_cache[c - 1] == NULL)
171ad23a2dbSjohansen 			zio_data_buf_cache[c - 1] = zio_data_buf_cache[c];
172fa9e4066Sahrens 	}
173ea8dc4b6Seschrock 
17409c9d376SGeorge Wilson 	/*
17509c9d376SGeorge Wilson 	 * The zio write taskqs have 1 thread per cpu, allow 1/2 of the taskqs
17609c9d376SGeorge Wilson 	 * to fail 3 times per txg or 8 failures, whichever is greater.
17709c9d376SGeorge Wilson 	 */
17809c9d376SGeorge Wilson 	zfs_mg_alloc_failures = MAX((3 * max_ncpus / 2), 8);
17909c9d376SGeorge Wilson 
180ea8dc4b6Seschrock 	zio_inject_init();
181fa9e4066Sahrens }
182fa9e4066Sahrens 
183fa9e4066Sahrens void
184fa9e4066Sahrens zio_fini(void)
185fa9e4066Sahrens {
186fa9e4066Sahrens 	size_t c;
187fa9e4066Sahrens 	kmem_cache_t *last_cache = NULL;
188ad23a2dbSjohansen 	kmem_cache_t *last_data_cache = NULL;
189fa9e4066Sahrens 
190fa9e4066Sahrens 	for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) {
191fa9e4066Sahrens 		if (zio_buf_cache[c] != last_cache) {
192fa9e4066Sahrens 			last_cache = zio_buf_cache[c];
193fa9e4066Sahrens 			kmem_cache_destroy(zio_buf_cache[c]);
194fa9e4066Sahrens 		}
195fa9e4066Sahrens 		zio_buf_cache[c] = NULL;
196ad23a2dbSjohansen 
197ad23a2dbSjohansen 		if (zio_data_buf_cache[c] != last_data_cache) {
198ad23a2dbSjohansen 			last_data_cache = zio_data_buf_cache[c];
199ad23a2dbSjohansen 			kmem_cache_destroy(zio_data_buf_cache[c]);
200ad23a2dbSjohansen 		}
201ad23a2dbSjohansen 		zio_data_buf_cache[c] = NULL;
202fa9e4066Sahrens 	}
203ea8dc4b6Seschrock 
204a3f829aeSBill Moore 	kmem_cache_destroy(zio_link_cache);
205ccae0b50Seschrock 	kmem_cache_destroy(zio_cache);
206ccae0b50Seschrock 
207ea8dc4b6Seschrock 	zio_inject_fini();
208fa9e4066Sahrens }
209fa9e4066Sahrens 
210fa9e4066Sahrens /*
211fa9e4066Sahrens  * ==========================================================================
212fa9e4066Sahrens  * Allocate and free I/O buffers
213fa9e4066Sahrens  * ==========================================================================
214fa9e4066Sahrens  */
215ad23a2dbSjohansen 
216ad23a2dbSjohansen /*
217ad23a2dbSjohansen  * Use zio_buf_alloc to allocate ZFS metadata.  This data will appear in a
218ad23a2dbSjohansen  * crashdump if the kernel panics, so use it judiciously.  Obviously, it's
219ad23a2dbSjohansen  * useful to inspect ZFS metadata, but if possible, we should avoid keeping
220ad23a2dbSjohansen  * excess / transient data in-core during a crashdump.
221ad23a2dbSjohansen  */
222fa9e4066Sahrens void *
223fa9e4066Sahrens zio_buf_alloc(size_t size)
224fa9e4066Sahrens {
225fa9e4066Sahrens 	size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
226fa9e4066Sahrens 
227fa9e4066Sahrens 	ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
228fa9e4066Sahrens 
2291ab7f2deSmaybee 	return (kmem_cache_alloc(zio_buf_cache[c], KM_PUSHPAGE));
230fa9e4066Sahrens }
231fa9e4066Sahrens 
232ad23a2dbSjohansen /*
233ad23a2dbSjohansen  * Use zio_data_buf_alloc to allocate data.  The data will not appear in a
234ad23a2dbSjohansen  * crashdump if the kernel panics.  This exists so that we will limit the amount
235ad23a2dbSjohansen  * of ZFS data that shows up in a kernel crashdump.  (Thus reducing the amount
236ad23a2dbSjohansen  * of kernel heap dumped to disk when the kernel panics)
237ad23a2dbSjohansen  */
238ad23a2dbSjohansen void *
239ad23a2dbSjohansen zio_data_buf_alloc(size_t size)
240ad23a2dbSjohansen {
241ad23a2dbSjohansen 	size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
242ad23a2dbSjohansen 
243ad23a2dbSjohansen 	ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
244ad23a2dbSjohansen 
2451ab7f2deSmaybee 	return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE));
246ad23a2dbSjohansen }
247ad23a2dbSjohansen 
248fa9e4066Sahrens void
249fa9e4066Sahrens zio_buf_free(void *buf, size_t size)
250fa9e4066Sahrens {
251fa9e4066Sahrens 	size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
252fa9e4066Sahrens 
253fa9e4066Sahrens 	ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
254fa9e4066Sahrens 
255fa9e4066Sahrens 	kmem_cache_free(zio_buf_cache[c], buf);
256fa9e4066Sahrens }
257fa9e4066Sahrens 
258ad23a2dbSjohansen void
259ad23a2dbSjohansen zio_data_buf_free(void *buf, size_t size)
260ad23a2dbSjohansen {
261ad23a2dbSjohansen 	size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
262ad23a2dbSjohansen 
263ad23a2dbSjohansen 	ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
264ad23a2dbSjohansen 
265ad23a2dbSjohansen 	kmem_cache_free(zio_data_buf_cache[c], buf);
266ad23a2dbSjohansen }
267b3995adbSahrens 
268fa9e4066Sahrens /*
269fa9e4066Sahrens  * ==========================================================================
270fa9e4066Sahrens  * Push and pop I/O transform buffers
271fa9e4066Sahrens  * ==========================================================================
272fa9e4066Sahrens  */
273fa9e4066Sahrens static void
274e14bb325SJeff Bonwick zio_push_transform(zio_t *zio, void *data, uint64_t size, uint64_t bufsize,
275e14bb325SJeff Bonwick 	zio_transform_func_t *transform)
276fa9e4066Sahrens {
277fa9e4066Sahrens 	zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP);
278fa9e4066Sahrens 
279e14bb325SJeff Bonwick 	zt->zt_orig_data = zio->io_data;
280e14bb325SJeff Bonwick 	zt->zt_orig_size = zio->io_size;
281fa9e4066Sahrens 	zt->zt_bufsize = bufsize;
282e14bb325SJeff Bonwick 	zt->zt_transform = transform;
283fa9e4066Sahrens 
284fa9e4066Sahrens 	zt->zt_next = zio->io_transform_stack;
285fa9e4066Sahrens 	zio->io_transform_stack = zt;
286fa9e4066Sahrens 
287fa9e4066Sahrens 	zio->io_data = data;
288fa9e4066Sahrens 	zio->io_size = size;
289fa9e4066Sahrens }
290fa9e4066Sahrens 
291fa9e4066Sahrens static void
292e14bb325SJeff Bonwick zio_pop_transforms(zio_t *zio)
293fa9e4066Sahrens {
294e14bb325SJeff Bonwick 	zio_transform_t *zt;
295e14bb325SJeff Bonwick 
296e14bb325SJeff Bonwick 	while ((zt = zio->io_transform_stack) != NULL) {
297e14bb325SJeff Bonwick 		if (zt->zt_transform != NULL)
298e14bb325SJeff Bonwick 			zt->zt_transform(zio,
299e14bb325SJeff Bonwick 			    zt->zt_orig_data, zt->zt_orig_size);
300fa9e4066Sahrens 
301b24ab676SJeff Bonwick 		if (zt->zt_bufsize != 0)
302b24ab676SJeff Bonwick 			zio_buf_free(zio->io_data, zt->zt_bufsize);
303fa9e4066Sahrens 
304e14bb325SJeff Bonwick 		zio->io_data = zt->zt_orig_data;
305e14bb325SJeff Bonwick 		zio->io_size = zt->zt_orig_size;
306e14bb325SJeff Bonwick 		zio->io_transform_stack = zt->zt_next;
307fa9e4066Sahrens 
308e14bb325SJeff Bonwick 		kmem_free(zt, sizeof (zio_transform_t));
309fa9e4066Sahrens 	}
310fa9e4066Sahrens }
311fa9e4066Sahrens 
312e14bb325SJeff Bonwick /*
313e14bb325SJeff Bonwick  * ==========================================================================
314e14bb325SJeff Bonwick  * I/O transform callbacks for subblocks and decompression
315e14bb325SJeff Bonwick  * ==========================================================================
316e14bb325SJeff Bonwick  */
317e14bb325SJeff Bonwick static void
318e14bb325SJeff Bonwick zio_subblock(zio_t *zio, void *data, uint64_t size)
319e14bb325SJeff Bonwick {
320e14bb325SJeff Bonwick 	ASSERT(zio->io_size > size);
321e14bb325SJeff Bonwick 
322e14bb325SJeff Bonwick 	if (zio->io_type == ZIO_TYPE_READ)
323e14bb325SJeff Bonwick 		bcopy(zio->io_data, data, size);
324e14bb325SJeff Bonwick }
325e14bb325SJeff Bonwick 
326e14bb325SJeff Bonwick static void
327e14bb325SJeff Bonwick zio_decompress(zio_t *zio, void *data, uint64_t size)
328e14bb325SJeff Bonwick {
329e14bb325SJeff Bonwick 	if (zio->io_error == 0 &&
330e14bb325SJeff Bonwick 	    zio_decompress_data(BP_GET_COMPRESS(zio->io_bp),
331b24ab676SJeff Bonwick 	    zio->io_data, data, zio->io_size, size) != 0)
332e14bb325SJeff Bonwick 		zio->io_error = EIO;
333e14bb325SJeff Bonwick }
334e14bb325SJeff Bonwick 
335e14bb325SJeff Bonwick /*
336e14bb325SJeff Bonwick  * ==========================================================================
337e14bb325SJeff Bonwick  * I/O parent/child relationships and pipeline interlocks
338e14bb325SJeff Bonwick  * ==========================================================================
339e14bb325SJeff Bonwick  */
340a3f829aeSBill Moore /*
341a3f829aeSBill Moore  * NOTE - Callers to zio_walk_parents() and zio_walk_children must
342a3f829aeSBill Moore  *        continue calling these functions until they return NULL.
343a3f829aeSBill Moore  *        Otherwise, the next caller will pick up the list walk in
344a3f829aeSBill Moore  *        some indeterminate state.  (Otherwise every caller would
345a3f829aeSBill Moore  *        have to pass in a cookie to keep the state represented by
346a3f829aeSBill Moore  *        io_walk_link, which gets annoying.)
347a3f829aeSBill Moore  */
348a3f829aeSBill Moore zio_t *
349a3f829aeSBill Moore zio_walk_parents(zio_t *cio)
350a3f829aeSBill Moore {
351a3f829aeSBill Moore 	zio_link_t *zl = cio->io_walk_link;
352a3f829aeSBill Moore 	list_t *pl = &cio->io_parent_list;
353e14bb325SJeff Bonwick 
354a3f829aeSBill Moore 	zl = (zl == NULL) ? list_head(pl) : list_next(pl, zl);
355a3f829aeSBill Moore 	cio->io_walk_link = zl;
356a3f829aeSBill Moore 
357a3f829aeSBill Moore 	if (zl == NULL)
358a3f829aeSBill Moore 		return (NULL);
359a3f829aeSBill Moore 
360a3f829aeSBill Moore 	ASSERT(zl->zl_child == cio);
361a3f829aeSBill Moore 	return (zl->zl_parent);
362a3f829aeSBill Moore }
363a3f829aeSBill Moore 
364a3f829aeSBill Moore zio_t *
365a3f829aeSBill Moore zio_walk_children(zio_t *pio)
366a3f829aeSBill Moore {
367a3f829aeSBill Moore 	zio_link_t *zl = pio->io_walk_link;
368a3f829aeSBill Moore 	list_t *cl = &pio->io_child_list;
369a3f829aeSBill Moore 
370a3f829aeSBill Moore 	zl = (zl == NULL) ? list_head(cl) : list_next(cl, zl);
371a3f829aeSBill Moore 	pio->io_walk_link = zl;
372a3f829aeSBill Moore 
373a3f829aeSBill Moore 	if (zl == NULL)
374a3f829aeSBill Moore 		return (NULL);
375a3f829aeSBill Moore 
376a3f829aeSBill Moore 	ASSERT(zl->zl_parent == pio);
377a3f829aeSBill Moore 	return (zl->zl_child);
378a3f829aeSBill Moore }
379a3f829aeSBill Moore 
380a3f829aeSBill Moore zio_t *
381a3f829aeSBill Moore zio_unique_parent(zio_t *cio)
382a3f829aeSBill Moore {
383a3f829aeSBill Moore 	zio_t *pio = zio_walk_parents(cio);
384a3f829aeSBill Moore 
385a3f829aeSBill Moore 	VERIFY(zio_walk_parents(cio) == NULL);
386a3f829aeSBill Moore 	return (pio);
387a3f829aeSBill Moore }
388a3f829aeSBill Moore 
389a3f829aeSBill Moore void
390a3f829aeSBill Moore zio_add_child(zio_t *pio, zio_t *cio)
391e14bb325SJeff Bonwick {
392a3f829aeSBill Moore 	zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP);
393a3f829aeSBill Moore 
394a3f829aeSBill Moore 	/*
395a3f829aeSBill Moore 	 * Logical I/Os can have logical, gang, or vdev children.
396a3f829aeSBill Moore 	 * Gang I/Os can have gang or vdev children.
397a3f829aeSBill Moore 	 * Vdev I/Os can only have vdev children.
398a3f829aeSBill Moore 	 * The following ASSERT captures all of these constraints.
399a3f829aeSBill Moore 	 */
400a3f829aeSBill Moore 	ASSERT(cio->io_child_type <= pio->io_child_type);
401a3f829aeSBill Moore 
402a3f829aeSBill Moore 	zl->zl_parent = pio;
403a3f829aeSBill Moore 	zl->zl_child = cio;
404a3f829aeSBill Moore 
405a3f829aeSBill Moore 	mutex_enter(&cio->io_lock);
406e14bb325SJeff Bonwick 	mutex_enter(&pio->io_lock);
407a3f829aeSBill Moore 
408a3f829aeSBill Moore 	ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0);
409a3f829aeSBill Moore 
410a3f829aeSBill Moore 	for (int w = 0; w < ZIO_WAIT_TYPES; w++)
411a3f829aeSBill Moore 		pio->io_children[cio->io_child_type][w] += !cio->io_state[w];
412a3f829aeSBill Moore 
413a3f829aeSBill Moore 	list_insert_head(&pio->io_child_list, zl);
414a3f829aeSBill Moore 	list_insert_head(&cio->io_parent_list, zl);
415a3f829aeSBill Moore 
416b24ab676SJeff Bonwick 	pio->io_child_count++;
417b24ab676SJeff Bonwick 	cio->io_parent_count++;
418b24ab676SJeff Bonwick 
419e14bb325SJeff Bonwick 	mutex_exit(&pio->io_lock);
420a3f829aeSBill Moore 	mutex_exit(&cio->io_lock);
421e14bb325SJeff Bonwick }
422e14bb325SJeff Bonwick 
423fa9e4066Sahrens static void
424a3f829aeSBill Moore zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl)
425e14bb325SJeff Bonwick {
426a3f829aeSBill Moore 	ASSERT(zl->zl_parent == pio);
427a3f829aeSBill Moore 	ASSERT(zl->zl_child == cio);
428e14bb325SJeff Bonwick 
429a3f829aeSBill Moore 	mutex_enter(&cio->io_lock);
430e14bb325SJeff Bonwick 	mutex_enter(&pio->io_lock);
431a3f829aeSBill Moore 
432a3f829aeSBill Moore 	list_remove(&pio->io_child_list, zl);
433a3f829aeSBill Moore 	list_remove(&cio->io_parent_list, zl);
434a3f829aeSBill Moore 
435b24ab676SJeff Bonwick 	pio->io_child_count--;
436b24ab676SJeff Bonwick 	cio->io_parent_count--;
437b24ab676SJeff Bonwick 
438e14bb325SJeff Bonwick 	mutex_exit(&pio->io_lock);
439a3f829aeSBill Moore 	mutex_exit(&cio->io_lock);
440a3f829aeSBill Moore 
441a3f829aeSBill Moore 	kmem_cache_free(zio_link_cache, zl);
442e14bb325SJeff Bonwick }
443e14bb325SJeff Bonwick 
444e14bb325SJeff Bonwick static boolean_t
445e14bb325SJeff Bonwick zio_wait_for_children(zio_t *zio, enum zio_child child, enum zio_wait_type wait)
446fa9e4066Sahrens {
447e14bb325SJeff Bonwick 	uint64_t *countp = &zio->io_children[child][wait];
448e14bb325SJeff Bonwick 	boolean_t waiting = B_FALSE;
449e14bb325SJeff Bonwick 
450e14bb325SJeff Bonwick 	mutex_enter(&zio->io_lock);
451e14bb325SJeff Bonwick 	ASSERT(zio->io_stall == NULL);
452e14bb325SJeff Bonwick 	if (*countp != 0) {
453b24ab676SJeff Bonwick 		zio->io_stage >>= 1;
454e14bb325SJeff Bonwick 		zio->io_stall = countp;
455e14bb325SJeff Bonwick 		waiting = B_TRUE;
456e14bb325SJeff Bonwick 	}
457e14bb325SJeff Bonwick 	mutex_exit(&zio->io_lock);
458e14bb325SJeff Bonwick 
459e14bb325SJeff Bonwick 	return (waiting);
460e14bb325SJeff Bonwick }
461fa9e4066Sahrens 
462e14bb325SJeff Bonwick static void
463e14bb325SJeff Bonwick zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait)
464e14bb325SJeff Bonwick {
465e14bb325SJeff Bonwick 	uint64_t *countp = &pio->io_children[zio->io_child_type][wait];
466e14bb325SJeff Bonwick 	int *errorp = &pio->io_child_error[zio->io_child_type];
467fa9e4066Sahrens 
468e14bb325SJeff Bonwick 	mutex_enter(&pio->io_lock);
469e14bb325SJeff Bonwick 	if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE))
470e14bb325SJeff Bonwick 		*errorp = zio_worst_error(*errorp, zio->io_error);
471e14bb325SJeff Bonwick 	pio->io_reexecute |= zio->io_reexecute;
472e14bb325SJeff Bonwick 	ASSERT3U(*countp, >, 0);
473e14bb325SJeff Bonwick 	if (--*countp == 0 && pio->io_stall == countp) {
474e14bb325SJeff Bonwick 		pio->io_stall = NULL;
475e14bb325SJeff Bonwick 		mutex_exit(&pio->io_lock);
476e14bb325SJeff Bonwick 		zio_execute(pio);
477e14bb325SJeff Bonwick 	} else {
478e14bb325SJeff Bonwick 		mutex_exit(&pio->io_lock);
479fa9e4066Sahrens 	}
480fa9e4066Sahrens }
481fa9e4066Sahrens 
482e14bb325SJeff Bonwick static void
483e14bb325SJeff Bonwick zio_inherit_child_errors(zio_t *zio, enum zio_child c)
484e14bb325SJeff Bonwick {
485e14bb325SJeff Bonwick 	if (zio->io_child_error[c] != 0 && zio->io_error == 0)
486e14bb325SJeff Bonwick 		zio->io_error = zio->io_child_error[c];
487e14bb325SJeff Bonwick }
488e14bb325SJeff Bonwick 
489fa9e4066Sahrens /*
490fa9e4066Sahrens  * ==========================================================================
491e14bb325SJeff Bonwick  * Create the various types of I/O (read, write, free, etc)
492fa9e4066Sahrens  * ==========================================================================
493fa9e4066Sahrens  */
494fa9e4066Sahrens static zio_t *
495b24ab676SJeff Bonwick zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
496fa9e4066Sahrens     void *data, uint64_t size, zio_done_func_t *done, void *private,
497b24ab676SJeff Bonwick     zio_type_t type, int priority, enum zio_flag flags,
498b24ab676SJeff Bonwick     vdev_t *vd, uint64_t offset, const zbookmark_t *zb,
499b24ab676SJeff Bonwick     enum zio_stage stage, enum zio_stage pipeline)
500fa9e4066Sahrens {
501fa9e4066Sahrens 	zio_t *zio;
502fa9e4066Sahrens 
503fa9e4066Sahrens 	ASSERT3U(size, <=, SPA_MAXBLOCKSIZE);
504fa9e4066Sahrens 	ASSERT(P2PHASE(size, SPA_MINBLOCKSIZE) == 0);
505e14bb325SJeff Bonwick 	ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0);
506fa9e4066Sahrens 
507e14bb325SJeff Bonwick 	ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER));
508e14bb325SJeff Bonwick 	ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER));
509e14bb325SJeff Bonwick 	ASSERT(vd || stage == ZIO_STAGE_OPEN);
510088f3894Sahrens 
511ccae0b50Seschrock 	zio = kmem_cache_alloc(zio_cache, KM_SLEEP);
512ccae0b50Seschrock 	bzero(zio, sizeof (zio_t));
513e14bb325SJeff Bonwick 
514e14bb325SJeff Bonwick 	mutex_init(&zio->io_lock, NULL, MUTEX_DEFAULT, NULL);
515e14bb325SJeff Bonwick 	cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL);
516e14bb325SJeff Bonwick 
517a3f829aeSBill Moore 	list_create(&zio->io_parent_list, sizeof (zio_link_t),
518a3f829aeSBill Moore 	    offsetof(zio_link_t, zl_parent_node));
519a3f829aeSBill Moore 	list_create(&zio->io_child_list, sizeof (zio_link_t),
520a3f829aeSBill Moore 	    offsetof(zio_link_t, zl_child_node));
521a3f829aeSBill Moore 
522e14bb325SJeff Bonwick 	if (vd != NULL)
523e14bb325SJeff Bonwick 		zio->io_child_type = ZIO_CHILD_VDEV;
524e14bb325SJeff Bonwick 	else if (flags & ZIO_FLAG_GANG_CHILD)
525e14bb325SJeff Bonwick 		zio->io_child_type = ZIO_CHILD_GANG;
526b24ab676SJeff Bonwick 	else if (flags & ZIO_FLAG_DDT_CHILD)
527b24ab676SJeff Bonwick 		zio->io_child_type = ZIO_CHILD_DDT;
528e14bb325SJeff Bonwick 	else
529e14bb325SJeff Bonwick 		zio->io_child_type = ZIO_CHILD_LOGICAL;
530e14bb325SJeff Bonwick 
531fa9e4066Sahrens 	if (bp != NULL) {
532b24ab676SJeff Bonwick 		zio->io_bp = (blkptr_t *)bp;
533fa9e4066Sahrens 		zio->io_bp_copy = *bp;
534fa9e4066Sahrens 		zio->io_bp_orig = *bp;
535b24ab676SJeff Bonwick 		if (type != ZIO_TYPE_WRITE ||
536b24ab676SJeff Bonwick 		    zio->io_child_type == ZIO_CHILD_DDT)
537e14bb325SJeff Bonwick 			zio->io_bp = &zio->io_bp_copy;	/* so caller can free */
538f5383399SBill Moore 		if (zio->io_child_type == ZIO_CHILD_LOGICAL)
539e14bb325SJeff Bonwick 			zio->io_logical = zio;
540f5383399SBill Moore 		if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp))
541f5383399SBill Moore 			pipeline |= ZIO_GANG_STAGES;
542fa9e4066Sahrens 	}
543e14bb325SJeff Bonwick 
544e14bb325SJeff Bonwick 	zio->io_spa = spa;
545e14bb325SJeff Bonwick 	zio->io_txg = txg;
546fa9e4066Sahrens 	zio->io_done = done;
547fa9e4066Sahrens 	zio->io_private = private;
548fa9e4066Sahrens 	zio->io_type = type;
549fa9e4066Sahrens 	zio->io_priority = priority;
550e14bb325SJeff Bonwick 	zio->io_vd = vd;
551e14bb325SJeff Bonwick 	zio->io_offset = offset;
552b24ab676SJeff Bonwick 	zio->io_orig_data = zio->io_data = data;
553b24ab676SJeff Bonwick 	zio->io_orig_size = zio->io_size = size;
554e14bb325SJeff Bonwick 	zio->io_orig_flags = zio->io_flags = flags;
555e14bb325SJeff Bonwick 	zio->io_orig_stage = zio->io_stage = stage;
556e14bb325SJeff Bonwick 	zio->io_orig_pipeline = zio->io_pipeline = pipeline;
557fa9e4066Sahrens 
558a3f829aeSBill Moore 	zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY);
559a3f829aeSBill Moore 	zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE);
560a3f829aeSBill Moore 
561e14bb325SJeff Bonwick 	if (zb != NULL)
562e14bb325SJeff Bonwick 		zio->io_bookmark = *zb;
563e14bb325SJeff Bonwick 
564e14bb325SJeff Bonwick 	if (pio != NULL) {
565e14bb325SJeff Bonwick 		if (zio->io_logical == NULL)
566ea8dc4b6Seschrock 			zio->io_logical = pio->io_logical;
567f5383399SBill Moore 		if (zio->io_child_type == ZIO_CHILD_GANG)
568f5383399SBill Moore 			zio->io_gang_leader = pio->io_gang_leader;
569e14bb325SJeff Bonwick 		zio_add_child(pio, zio);
570fa9e4066Sahrens 	}
571fa9e4066Sahrens 
572fa9e4066Sahrens 	return (zio);
573fa9e4066Sahrens }
574fa9e4066Sahrens 
5750a4e9518Sgw static void
576e14bb325SJeff Bonwick zio_destroy(zio_t *zio)
5770a4e9518Sgw {
578a3f829aeSBill Moore 	list_destroy(&zio->io_parent_list);
579a3f829aeSBill Moore 	list_destroy(&zio->io_child_list);
580e14bb325SJeff Bonwick 	mutex_destroy(&zio->io_lock);
581e14bb325SJeff Bonwick 	cv_destroy(&zio->io_cv);
582e14bb325SJeff Bonwick 	kmem_cache_free(zio_cache, zio);
5830a4e9518Sgw }
5840a4e9518Sgw 
585fa9e4066Sahrens zio_t *
586a3f829aeSBill Moore zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done,
587b24ab676SJeff Bonwick     void *private, enum zio_flag flags)
588fa9e4066Sahrens {
589fa9e4066Sahrens 	zio_t *zio;
590fa9e4066Sahrens 
591fa9e4066Sahrens 	zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private,
592a3f829aeSBill Moore 	    ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL,
593e14bb325SJeff Bonwick 	    ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE);
594fa9e4066Sahrens 
595fa9e4066Sahrens 	return (zio);
596fa9e4066Sahrens }
597fa9e4066Sahrens 
598fa9e4066Sahrens zio_t *
599b24ab676SJeff Bonwick zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags)
600fa9e4066Sahrens {
601a3f829aeSBill Moore 	return (zio_null(NULL, spa, NULL, done, private, flags));
602fa9e4066Sahrens }
603fa9e4066Sahrens 
604fa9e4066Sahrens zio_t *
605e14bb325SJeff Bonwick zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
606e14bb325SJeff Bonwick     void *data, uint64_t size, zio_done_func_t *done, void *private,
607b24ab676SJeff Bonwick     int priority, enum zio_flag flags, const zbookmark_t *zb)
608fa9e4066Sahrens {
609fa9e4066Sahrens 	zio_t *zio;
610fa9e4066Sahrens 
611b24ab676SJeff Bonwick 	zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp,
612088f3894Sahrens 	    data, size, done, private,
613e14bb325SJeff Bonwick 	    ZIO_TYPE_READ, priority, flags, NULL, 0, zb,
614b24ab676SJeff Bonwick 	    ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ?
615b24ab676SJeff Bonwick 	    ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE);
616fa9e4066Sahrens 
617fa9e4066Sahrens 	return (zio);
618fa9e4066Sahrens }
619fa9e4066Sahrens 
620fa9e4066Sahrens zio_t *
621e14bb325SJeff Bonwick zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
622b24ab676SJeff Bonwick     void *data, uint64_t size, const zio_prop_t *zp,
623e14bb325SJeff Bonwick     zio_done_func_t *ready, zio_done_func_t *done, void *private,
624b24ab676SJeff Bonwick     int priority, enum zio_flag flags, const zbookmark_t *zb)
625fa9e4066Sahrens {
626fa9e4066Sahrens 	zio_t *zio;
627fa9e4066Sahrens 
628e14bb325SJeff Bonwick 	ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF &&
629e14bb325SJeff Bonwick 	    zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS &&
630e14bb325SJeff Bonwick 	    zp->zp_compress >= ZIO_COMPRESS_OFF &&
631e14bb325SJeff Bonwick 	    zp->zp_compress < ZIO_COMPRESS_FUNCTIONS &&
632ad135b5dSChristopher Siden 	    DMU_OT_IS_VALID(zp->zp_type) &&
633e14bb325SJeff Bonwick 	    zp->zp_level < 32 &&
634b24ab676SJeff Bonwick 	    zp->zp_copies > 0 &&
635b24ab676SJeff Bonwick 	    zp->zp_copies <= spa_max_replication(spa) &&
636b24ab676SJeff Bonwick 	    zp->zp_dedup <= 1 &&
637b24ab676SJeff Bonwick 	    zp->zp_dedup_verify <= 1);
6380a4e9518Sgw 
639fa9e4066Sahrens 	zio = zio_create(pio, spa, txg, bp, data, size, done, private,
640e14bb325SJeff Bonwick 	    ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb,
641b24ab676SJeff Bonwick 	    ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ?
642b24ab676SJeff Bonwick 	    ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE);
643fa9e4066Sahrens 
644c717a561Smaybee 	zio->io_ready = ready;
645e14bb325SJeff Bonwick 	zio->io_prop = *zp;
646fa9e4066Sahrens 
647fa9e4066Sahrens 	return (zio);
648fa9e4066Sahrens }
649fa9e4066Sahrens 
650fa9e4066Sahrens zio_t *
651e14bb325SJeff Bonwick zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, void *data,
652e14bb325SJeff Bonwick     uint64_t size, zio_done_func_t *done, void *private, int priority,
653b24ab676SJeff Bonwick     enum zio_flag flags, zbookmark_t *zb)
654fa9e4066Sahrens {
655fa9e4066Sahrens 	zio_t *zio;
656fa9e4066Sahrens 
657fa9e4066Sahrens 	zio = zio_create(pio, spa, txg, bp, data, size, done, private,
658e14bb325SJeff Bonwick 	    ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb,
659e14bb325SJeff Bonwick 	    ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE);
660fa9e4066Sahrens 
661fa9e4066Sahrens 	return (zio);
662fa9e4066Sahrens }
663fa9e4066Sahrens 
664b24ab676SJeff Bonwick void
665b24ab676SJeff Bonwick zio_write_override(zio_t *zio, blkptr_t *bp, int copies)
666b24ab676SJeff Bonwick {
667b24ab676SJeff Bonwick 	ASSERT(zio->io_type == ZIO_TYPE_WRITE);
668b24ab676SJeff Bonwick 	ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
669b24ab676SJeff Bonwick 	ASSERT(zio->io_stage == ZIO_STAGE_OPEN);
670b24ab676SJeff Bonwick 	ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa));
671b24ab676SJeff Bonwick 
672b24ab676SJeff Bonwick 	zio->io_prop.zp_copies = copies;
673b24ab676SJeff Bonwick 	zio->io_bp_override = bp;
674b24ab676SJeff Bonwick }
675b24ab676SJeff Bonwick 
676b24ab676SJeff Bonwick void
677b24ab676SJeff Bonwick zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp)
678b24ab676SJeff Bonwick {
679cde58dbcSMatthew Ahrens 	bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp);
680b24ab676SJeff Bonwick }
681b24ab676SJeff Bonwick 
682fa9e4066Sahrens zio_t *
683b24ab676SJeff Bonwick zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
684b24ab676SJeff Bonwick     enum zio_flag flags)
685fa9e4066Sahrens {
686fa9e4066Sahrens 	zio_t *zio;
687fa9e4066Sahrens 
6883f9d6ad7SLin Ling 	dprintf_bp(bp, "freeing in txg %llu, pass %u",
6893f9d6ad7SLin Ling 	    (longlong_t)txg, spa->spa_sync_pass);
6903f9d6ad7SLin Ling 
691fa9e4066Sahrens 	ASSERT(!BP_IS_HOLE(bp));
692b24ab676SJeff Bonwick 	ASSERT(spa_syncing_txg(spa) == txg);
693b24ab676SJeff Bonwick 	ASSERT(spa_sync_pass(spa) <= SYNC_PASS_DEFERRED_FREE);
694fa9e4066Sahrens 
695e14bb325SJeff Bonwick 	zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp),
696b24ab676SJeff Bonwick 	    NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_FREE, flags,
697e14bb325SJeff Bonwick 	    NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_FREE_PIPELINE);
698fa9e4066Sahrens 
699fa9e4066Sahrens 	return (zio);
700fa9e4066Sahrens }
701fa9e4066Sahrens 
702fa9e4066Sahrens zio_t *
703b24ab676SJeff Bonwick zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
704b24ab676SJeff Bonwick     zio_done_func_t *done, void *private, enum zio_flag flags)
705fa9e4066Sahrens {
706fa9e4066Sahrens 	zio_t *zio;
707fa9e4066Sahrens 
708fa9e4066Sahrens 	/*
709fa9e4066Sahrens 	 * A claim is an allocation of a specific block.  Claims are needed
710fa9e4066Sahrens 	 * to support immediate writes in the intent log.  The issue is that
711fa9e4066Sahrens 	 * immediate writes contain committed data, but in a txg that was
712fa9e4066Sahrens 	 * *not* committed.  Upon opening the pool after an unclean shutdown,
713fa9e4066Sahrens 	 * the intent log claims all blocks that contain immediate write data
714fa9e4066Sahrens 	 * so that the SPA knows they're in use.
715fa9e4066Sahrens 	 *
716fa9e4066Sahrens 	 * All claims *must* be resolved in the first txg -- before the SPA
717fa9e4066Sahrens 	 * starts allocating blocks -- so that nothing is allocated twice.
718b24ab676SJeff Bonwick 	 * If txg == 0 we just verify that the block is claimable.
719fa9e4066Sahrens 	 */
720fa9e4066Sahrens 	ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <, spa_first_txg(spa));
721b24ab676SJeff Bonwick 	ASSERT(txg == spa_first_txg(spa) || txg == 0);
722b24ab676SJeff Bonwick 	ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa));	/* zdb(1M) */
723fa9e4066Sahrens 
724e14bb325SJeff Bonwick 	zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp),
725e14bb325SJeff Bonwick 	    done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, flags,
726e14bb325SJeff Bonwick 	    NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE);
727fa9e4066Sahrens 
728fa9e4066Sahrens 	return (zio);
729fa9e4066Sahrens }
730fa9e4066Sahrens 
731fa9e4066Sahrens zio_t *
732fa9e4066Sahrens zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
733b24ab676SJeff Bonwick     zio_done_func_t *done, void *private, int priority, enum zio_flag flags)
734fa9e4066Sahrens {
735fa9e4066Sahrens 	zio_t *zio;
736fa9e4066Sahrens 	int c;
737fa9e4066Sahrens 
738fa9e4066Sahrens 	if (vd->vdev_children == 0) {
739fa9e4066Sahrens 		zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private,
740e14bb325SJeff Bonwick 		    ZIO_TYPE_IOCTL, priority, flags, vd, 0, NULL,
741fa9e4066Sahrens 		    ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE);
742fa9e4066Sahrens 
743fa9e4066Sahrens 		zio->io_cmd = cmd;
744fa9e4066Sahrens 	} else {
745a3f829aeSBill Moore 		zio = zio_null(pio, spa, NULL, NULL, NULL, flags);
746fa9e4066Sahrens 
747fa9e4066Sahrens 		for (c = 0; c < vd->vdev_children; c++)
748fa9e4066Sahrens 			zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd,
749fa9e4066Sahrens 			    done, private, priority, flags));
750fa9e4066Sahrens 	}
751fa9e4066Sahrens 
752fa9e4066Sahrens 	return (zio);
753fa9e4066Sahrens }
754fa9e4066Sahrens 
755fa9e4066Sahrens zio_t *
756fa9e4066Sahrens zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
757fa9e4066Sahrens     void *data, int checksum, zio_done_func_t *done, void *private,
758b24ab676SJeff Bonwick     int priority, enum zio_flag flags, boolean_t labels)
759fa9e4066Sahrens {
760fa9e4066Sahrens 	zio_t *zio;
7610a4e9518Sgw 
762e14bb325SJeff Bonwick 	ASSERT(vd->vdev_children == 0);
763e14bb325SJeff Bonwick 	ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE ||
764e14bb325SJeff Bonwick 	    offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE);
765e14bb325SJeff Bonwick 	ASSERT3U(offset + size, <=, vd->vdev_psize);
766fa9e4066Sahrens 
767e14bb325SJeff Bonwick 	zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private,
768e14bb325SJeff Bonwick 	    ZIO_TYPE_READ, priority, flags, vd, offset, NULL,
769fa9e4066Sahrens 	    ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE);
770fa9e4066Sahrens 
771e14bb325SJeff Bonwick 	zio->io_prop.zp_checksum = checksum;
772fa9e4066Sahrens 
773fa9e4066Sahrens 	return (zio);
774fa9e4066Sahrens }
775fa9e4066Sahrens 
776fa9e4066Sahrens zio_t *
777fa9e4066Sahrens zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
778fa9e4066Sahrens     void *data, int checksum, zio_done_func_t *done, void *private,
779b24ab676SJeff Bonwick     int priority, enum zio_flag flags, boolean_t labels)
780fa9e4066Sahrens {
781fa9e4066Sahrens 	zio_t *zio;
7820a4e9518Sgw 
783e14bb325SJeff Bonwick 	ASSERT(vd->vdev_children == 0);
784e14bb325SJeff Bonwick 	ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE ||
785e14bb325SJeff Bonwick 	    offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE);
786e14bb325SJeff Bonwick 	ASSERT3U(offset + size, <=, vd->vdev_psize);
787fa9e4066Sahrens 
788e14bb325SJeff Bonwick 	zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private,
789e14bb325SJeff Bonwick 	    ZIO_TYPE_WRITE, priority, flags, vd, offset, NULL,
790fa9e4066Sahrens 	    ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE);
791fa9e4066Sahrens 
792e14bb325SJeff Bonwick 	zio->io_prop.zp_checksum = checksum;
793fa9e4066Sahrens 
7946e1f5caaSNeil Perrin 	if (zio_checksum_table[checksum].ci_eck) {
795fa9e4066Sahrens 		/*
7966e1f5caaSNeil Perrin 		 * zec checksums are necessarily destructive -- they modify
797e14bb325SJeff Bonwick 		 * the end of the write buffer to hold the verifier/checksum.
798fa9e4066Sahrens 		 * Therefore, we must make a local copy in case the data is
799e14bb325SJeff Bonwick 		 * being written to multiple places in parallel.
800fa9e4066Sahrens 		 */
801e14bb325SJeff Bonwick 		void *wbuf = zio_buf_alloc(size);
802fa9e4066Sahrens 		bcopy(data, wbuf, size);
803e14bb325SJeff Bonwick 		zio_push_transform(zio, wbuf, size, size, NULL);
804fa9e4066Sahrens 	}
805fa9e4066Sahrens 
806fa9e4066Sahrens 	return (zio);
807fa9e4066Sahrens }
808fa9e4066Sahrens 
809fa9e4066Sahrens /*
810e14bb325SJeff Bonwick  * Create a child I/O to do some work for us.
811fa9e4066Sahrens  */
812fa9e4066Sahrens zio_t *
813e14bb325SJeff Bonwick zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset,
814b24ab676SJeff Bonwick 	void *data, uint64_t size, int type, int priority, enum zio_flag flags,
815fa9e4066Sahrens 	zio_done_func_t *done, void *private)
816fa9e4066Sahrens {
817b24ab676SJeff Bonwick 	enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE;
818e14bb325SJeff Bonwick 	zio_t *zio;
819e14bb325SJeff Bonwick 
820e14bb325SJeff Bonwick 	ASSERT(vd->vdev_parent ==
821e14bb325SJeff Bonwick 	    (pio->io_vd ? pio->io_vd : pio->io_spa->spa_root_vdev));
822fa9e4066Sahrens 
823fa9e4066Sahrens 	if (type == ZIO_TYPE_READ && bp != NULL) {
824fa9e4066Sahrens 		/*
825fa9e4066Sahrens 		 * If we have the bp, then the child should perform the
826fa9e4066Sahrens 		 * checksum and the parent need not.  This pushes error
827fa9e4066Sahrens 		 * detection as close to the leaves as possible and
828fa9e4066Sahrens 		 * eliminates redundant checksums in the interior nodes.
829fa9e4066Sahrens 		 */
830b24ab676SJeff Bonwick 		pipeline |= ZIO_STAGE_CHECKSUM_VERIFY;
831b24ab676SJeff Bonwick 		pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY;
832fa9e4066Sahrens 	}
833fa9e4066Sahrens 
834e14bb325SJeff Bonwick 	if (vd->vdev_children == 0)
835e14bb325SJeff Bonwick 		offset += VDEV_LABEL_START_SIZE;
836e14bb325SJeff Bonwick 
837b24ab676SJeff Bonwick 	flags |= ZIO_VDEV_CHILD_FLAGS(pio) | ZIO_FLAG_DONT_PROPAGATE;
838b24ab676SJeff Bonwick 
839b24ab676SJeff Bonwick 	/*
840b24ab676SJeff Bonwick 	 * If we've decided to do a repair, the write is not speculative --
841b24ab676SJeff Bonwick 	 * even if the original read was.
842b24ab676SJeff Bonwick 	 */
843b24ab676SJeff Bonwick 	if (flags & ZIO_FLAG_IO_REPAIR)
844b24ab676SJeff Bonwick 		flags &= ~ZIO_FLAG_SPECULATIVE;
845b24ab676SJeff Bonwick 
846e14bb325SJeff Bonwick 	zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size,
847b24ab676SJeff Bonwick 	    done, private, type, priority, flags, vd, offset, &pio->io_bookmark,
848b24ab676SJeff Bonwick 	    ZIO_STAGE_VDEV_IO_START >> 1, pipeline);
849fa9e4066Sahrens 
850e14bb325SJeff Bonwick 	return (zio);
85132b87932Sek }
85232b87932Sek 
853e14bb325SJeff Bonwick zio_t *
854e14bb325SJeff Bonwick zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, void *data, uint64_t size,
855b24ab676SJeff Bonwick 	int type, int priority, enum zio_flag flags,
856b24ab676SJeff Bonwick 	zio_done_func_t *done, void *private)
857fa9e4066Sahrens {
858e14bb325SJeff Bonwick 	zio_t *zio;
859fa9e4066Sahrens 
860e14bb325SJeff Bonwick 	ASSERT(vd->vdev_ops->vdev_op_leaf);
861fa9e4066Sahrens 
862e14bb325SJeff Bonwick 	zio = zio_create(NULL, vd->vdev_spa, 0, NULL,
863e14bb325SJeff Bonwick 	    data, size, done, private, type, priority,
864e14bb325SJeff Bonwick 	    flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY,
865e14bb325SJeff Bonwick 	    vd, offset, NULL,
866b24ab676SJeff Bonwick 	    ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE);
867fa9e4066Sahrens 
868e14bb325SJeff Bonwick 	return (zio);
869e05725b1Sbonwick }
870e05725b1Sbonwick 
871e05725b1Sbonwick void
872e14bb325SJeff Bonwick zio_flush(zio_t *zio, vdev_t *vd)
873e05725b1Sbonwick {
874e14bb325SJeff Bonwick 	zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE,
875e14bb325SJeff Bonwick 	    NULL, NULL, ZIO_PRIORITY_NOW,
876e14bb325SJeff Bonwick 	    ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY));
877fa9e4066Sahrens }
878fa9e4066Sahrens 
8796e1f5caaSNeil Perrin void
8806e1f5caaSNeil Perrin zio_shrink(zio_t *zio, uint64_t size)
8816e1f5caaSNeil Perrin {
8826e1f5caaSNeil Perrin 	ASSERT(zio->io_executor == NULL);
8836e1f5caaSNeil Perrin 	ASSERT(zio->io_orig_size == zio->io_size);
8846e1f5caaSNeil Perrin 	ASSERT(size <= zio->io_size);
8856e1f5caaSNeil Perrin 
8866e1f5caaSNeil Perrin 	/*
8876e1f5caaSNeil Perrin 	 * We don't shrink for raidz because of problems with the
8886e1f5caaSNeil Perrin 	 * reconstruction when reading back less than the block size.
8896e1f5caaSNeil Perrin 	 * Note, BP_IS_RAIDZ() assumes no compression.
8906e1f5caaSNeil Perrin 	 */
8916e1f5caaSNeil Perrin 	ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF);
8926e1f5caaSNeil Perrin 	if (!BP_IS_RAIDZ(zio->io_bp))
8936e1f5caaSNeil Perrin 		zio->io_orig_size = zio->io_size = size;
8946e1f5caaSNeil Perrin }
8956e1f5caaSNeil Perrin 
896fa9e4066Sahrens /*
897fa9e4066Sahrens  * ==========================================================================
898e14bb325SJeff Bonwick  * Prepare to read and write logical blocks
899fa9e4066Sahrens  * ==========================================================================
900fa9e4066Sahrens  */
901e14bb325SJeff Bonwick 
902e05725b1Sbonwick static int
903e14bb325SJeff Bonwick zio_read_bp_init(zio_t *zio)
904fa9e4066Sahrens {
905e14bb325SJeff Bonwick 	blkptr_t *bp = zio->io_bp;
906e05725b1Sbonwick 
90703361682SJeff Bonwick 	if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF &&
908f5383399SBill Moore 	    zio->io_child_type == ZIO_CHILD_LOGICAL &&
909f5383399SBill Moore 	    !(zio->io_flags & ZIO_FLAG_RAW)) {
910b24ab676SJeff Bonwick 		uint64_t psize = BP_GET_PSIZE(bp);
911b24ab676SJeff Bonwick 		void *cbuf = zio_buf_alloc(psize);
912e05725b1Sbonwick 
913b24ab676SJeff Bonwick 		zio_push_transform(zio, cbuf, psize, psize, zio_decompress);
914e14bb325SJeff Bonwick 	}
915fa9e4066Sahrens 
916ad135b5dSChristopher Siden 	if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0)
917e14bb325SJeff Bonwick 		zio->io_flags |= ZIO_FLAG_DONT_CACHE;
918fa9e4066Sahrens 
919bbfd46c4SJeff Bonwick 	if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP)
920bbfd46c4SJeff Bonwick 		zio->io_flags |= ZIO_FLAG_DONT_CACHE;
921bbfd46c4SJeff Bonwick 
922b24ab676SJeff Bonwick 	if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL)
923b24ab676SJeff Bonwick 		zio->io_pipeline = ZIO_DDT_READ_PIPELINE;
924b24ab676SJeff Bonwick 
925e14bb325SJeff Bonwick 	return (ZIO_PIPELINE_CONTINUE);
926fa9e4066Sahrens }
927fa9e4066Sahrens 
928e05725b1Sbonwick static int
929e14bb325SJeff Bonwick zio_write_bp_init(zio_t *zio)
9300a4e9518Sgw {
931b24ab676SJeff Bonwick 	spa_t *spa = zio->io_spa;
932e14bb325SJeff Bonwick 	zio_prop_t *zp = &zio->io_prop;
933b24ab676SJeff Bonwick 	enum zio_compress compress = zp->zp_compress;
934e05725b1Sbonwick 	blkptr_t *bp = zio->io_bp;
935e14bb325SJeff Bonwick 	uint64_t lsize = zio->io_size;
936b24ab676SJeff Bonwick 	uint64_t psize = lsize;
937e14bb325SJeff Bonwick 	int pass = 1;
938e05725b1Sbonwick 
939e14bb325SJeff Bonwick 	/*
940e14bb325SJeff Bonwick 	 * If our children haven't all reached the ready stage,
941e14bb325SJeff Bonwick 	 * wait for them and then repeat this pipeline stage.
942e14bb325SJeff Bonwick 	 */
943e14bb325SJeff Bonwick 	if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) ||
944e14bb325SJeff Bonwick 	    zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_READY))
945e14bb325SJeff Bonwick 		return (ZIO_PIPELINE_STOP);
9460a4e9518Sgw 
947e14bb325SJeff Bonwick 	if (!IO_IS_ALLOCATING(zio))
948e14bb325SJeff Bonwick 		return (ZIO_PIPELINE_CONTINUE);
9490a4e9518Sgw 
950b24ab676SJeff Bonwick 	ASSERT(zio->io_child_type != ZIO_CHILD_DDT);
951b24ab676SJeff Bonwick 
952b24ab676SJeff Bonwick 	if (zio->io_bp_override) {
953b24ab676SJeff Bonwick 		ASSERT(bp->blk_birth != zio->io_txg);
954b24ab676SJeff Bonwick 		ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0);
955b24ab676SJeff Bonwick 
956b24ab676SJeff Bonwick 		*bp = *zio->io_bp_override;
957b24ab676SJeff Bonwick 		zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
958b24ab676SJeff Bonwick 
959b24ab676SJeff Bonwick 		if (BP_IS_HOLE(bp) || !zp->zp_dedup)
960b24ab676SJeff Bonwick 			return (ZIO_PIPELINE_CONTINUE);
961b24ab676SJeff Bonwick 
962b24ab676SJeff Bonwick 		ASSERT(zio_checksum_table[zp->zp_checksum].ci_dedup ||
963b24ab676SJeff Bonwick 		    zp->zp_dedup_verify);
964b24ab676SJeff Bonwick 
965b24ab676SJeff Bonwick 		if (BP_GET_CHECKSUM(bp) == zp->zp_checksum) {
966b24ab676SJeff Bonwick 			BP_SET_DEDUP(bp, 1);
967b24ab676SJeff Bonwick 			zio->io_pipeline |= ZIO_STAGE_DDT_WRITE;
968b24ab676SJeff Bonwick 			return (ZIO_PIPELINE_CONTINUE);
969b24ab676SJeff Bonwick 		}
970b24ab676SJeff Bonwick 		zio->io_bp_override = NULL;
971b24ab676SJeff Bonwick 		BP_ZERO(bp);
972b24ab676SJeff Bonwick 	}
9730a4e9518Sgw 
974e14bb325SJeff Bonwick 	if (bp->blk_birth == zio->io_txg) {
975e14bb325SJeff Bonwick 		/*
976e14bb325SJeff Bonwick 		 * We're rewriting an existing block, which means we're
977e14bb325SJeff Bonwick 		 * working on behalf of spa_sync().  For spa_sync() to
978e14bb325SJeff Bonwick 		 * converge, it must eventually be the case that we don't
979e14bb325SJeff Bonwick 		 * have to allocate new blocks.  But compression changes
980e14bb325SJeff Bonwick 		 * the blocksize, which forces a reallocate, and makes
981e14bb325SJeff Bonwick 		 * convergence take longer.  Therefore, after the first
982e14bb325SJeff Bonwick 		 * few passes, stop compressing to ensure convergence.
983e14bb325SJeff Bonwick 		 */
984b24ab676SJeff Bonwick 		pass = spa_sync_pass(spa);
985b24ab676SJeff Bonwick 
986b24ab676SJeff Bonwick 		ASSERT(zio->io_txg == spa_syncing_txg(spa));
987b24ab676SJeff Bonwick 		ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
988b24ab676SJeff Bonwick 		ASSERT(!BP_GET_DEDUP(bp));
989e05725b1Sbonwick 
990e14bb325SJeff Bonwick 		if (pass > SYNC_PASS_DONT_COMPRESS)
991e14bb325SJeff Bonwick 			compress = ZIO_COMPRESS_OFF;
992e05725b1Sbonwick 
993e14bb325SJeff Bonwick 		/* Make sure someone doesn't change their mind on overwrites */
994b24ab676SJeff Bonwick 		ASSERT(MIN(zp->zp_copies + BP_IS_GANG(bp),
995b24ab676SJeff Bonwick 		    spa_max_replication(spa)) == BP_GET_NDVAS(bp));
996e14bb325SJeff Bonwick 	}
997fa9e4066Sahrens 
998e14bb325SJeff Bonwick 	if (compress != ZIO_COMPRESS_OFF) {
999b24ab676SJeff Bonwick 		void *cbuf = zio_buf_alloc(lsize);
1000b24ab676SJeff Bonwick 		psize = zio_compress_data(compress, zio->io_data, cbuf, lsize);
1001b24ab676SJeff Bonwick 		if (psize == 0 || psize == lsize) {
1002e14bb325SJeff Bonwick 			compress = ZIO_COMPRESS_OFF;
1003b24ab676SJeff Bonwick 			zio_buf_free(cbuf, lsize);
1004b24ab676SJeff Bonwick 		} else {
1005b24ab676SJeff Bonwick 			ASSERT(psize < lsize);
1006b24ab676SJeff Bonwick 			zio_push_transform(zio, cbuf, psize, lsize, NULL);
1007e14bb325SJeff Bonwick 		}
1008e14bb325SJeff Bonwick 	}
1009c717a561Smaybee 
1010e14bb325SJeff Bonwick 	/*
1011e14bb325SJeff Bonwick 	 * The final pass of spa_sync() must be all rewrites, but the first
1012e14bb325SJeff Bonwick 	 * few passes offer a trade-off: allocating blocks defers convergence,
1013e14bb325SJeff Bonwick 	 * but newly allocated blocks are sequential, so they can be written
1014e14bb325SJeff Bonwick 	 * to disk faster.  Therefore, we allow the first few passes of
1015e14bb325SJeff Bonwick 	 * spa_sync() to allocate new blocks, but force rewrites after that.
1016e14bb325SJeff Bonwick 	 * There should only be a handful of blocks after pass 1 in any case.
1017e14bb325SJeff Bonwick 	 */
1018b24ab676SJeff Bonwick 	if (bp->blk_birth == zio->io_txg && BP_GET_PSIZE(bp) == psize &&
1019e14bb325SJeff Bonwick 	    pass > SYNC_PASS_REWRITE) {
1020b24ab676SJeff Bonwick 		ASSERT(psize != 0);
1021b24ab676SJeff Bonwick 		enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES;
1022e14bb325SJeff Bonwick 		zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages;
1023e14bb325SJeff Bonwick 		zio->io_flags |= ZIO_FLAG_IO_REWRITE;
1024e14bb325SJeff Bonwick 	} else {
1025e14bb325SJeff Bonwick 		BP_ZERO(bp);
1026e14bb325SJeff Bonwick 		zio->io_pipeline = ZIO_WRITE_PIPELINE;
1027e14bb325SJeff Bonwick 	}
1028fa9e4066Sahrens 
1029b24ab676SJeff Bonwick 	if (psize == 0) {
1030e14bb325SJeff Bonwick 		zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1031e14bb325SJeff Bonwick 	} else {
1032e14bb325SJeff Bonwick 		ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER);
1033e14bb325SJeff Bonwick 		BP_SET_LSIZE(bp, lsize);
1034b24ab676SJeff Bonwick 		BP_SET_PSIZE(bp, psize);
1035e14bb325SJeff Bonwick 		BP_SET_COMPRESS(bp, compress);
1036e14bb325SJeff Bonwick 		BP_SET_CHECKSUM(bp, zp->zp_checksum);
1037e14bb325SJeff Bonwick 		BP_SET_TYPE(bp, zp->zp_type);
1038e14bb325SJeff Bonwick 		BP_SET_LEVEL(bp, zp->zp_level);
1039b24ab676SJeff Bonwick 		BP_SET_DEDUP(bp, zp->zp_dedup);
1040e14bb325SJeff Bonwick 		BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER);
1041b24ab676SJeff Bonwick 		if (zp->zp_dedup) {
1042b24ab676SJeff Bonwick 			ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1043b24ab676SJeff Bonwick 			ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
1044b24ab676SJeff Bonwick 			zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE;
1045b24ab676SJeff Bonwick 		}
1046b24ab676SJeff Bonwick 	}
1047b24ab676SJeff Bonwick 
1048b24ab676SJeff Bonwick 	return (ZIO_PIPELINE_CONTINUE);
1049b24ab676SJeff Bonwick }
1050b24ab676SJeff Bonwick 
1051b24ab676SJeff Bonwick static int
1052b24ab676SJeff Bonwick zio_free_bp_init(zio_t *zio)
1053b24ab676SJeff Bonwick {
1054b24ab676SJeff Bonwick 	blkptr_t *bp = zio->io_bp;
1055b24ab676SJeff Bonwick 
1056b24ab676SJeff Bonwick 	if (zio->io_child_type == ZIO_CHILD_LOGICAL) {
1057b24ab676SJeff Bonwick 		if (BP_GET_DEDUP(bp))
1058b24ab676SJeff Bonwick 			zio->io_pipeline = ZIO_DDT_FREE_PIPELINE;
1059e14bb325SJeff Bonwick 	}
1060fa9e4066Sahrens 
1061e05725b1Sbonwick 	return (ZIO_PIPELINE_CONTINUE);
1062fa9e4066Sahrens }
1063fa9e4066Sahrens 
1064e14bb325SJeff Bonwick /*
1065e14bb325SJeff Bonwick  * ==========================================================================
1066e14bb325SJeff Bonwick  * Execute the I/O pipeline
1067e14bb325SJeff Bonwick  * ==========================================================================
1068e14bb325SJeff Bonwick  */
1069e14bb325SJeff Bonwick 
1070e14bb325SJeff Bonwick static void
107135a5a358SJonathan Adams zio_taskq_dispatch(zio_t *zio, enum zio_taskq_type q, boolean_t cutinline)
1072fa9e4066Sahrens {
107380eb36f2SGeorge Wilson 	spa_t *spa = zio->io_spa;
1074e14bb325SJeff Bonwick 	zio_type_t t = zio->io_type;
10755aeb9474SGarrett D'Amore 	int flags = (cutinline ? TQ_FRONT : 0);
10760a4e9518Sgw 
10770a4e9518Sgw 	/*
1078bbe36defSGeorge Wilson 	 * If we're a config writer or a probe, the normal issue and
1079bbe36defSGeorge Wilson 	 * interrupt threads may all be blocked waiting for the config lock.
1080bbe36defSGeorge Wilson 	 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL.
10810a4e9518Sgw 	 */
1082bbe36defSGeorge Wilson 	if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE))
1083e14bb325SJeff Bonwick 		t = ZIO_TYPE_NULL;
10840a4e9518Sgw 
10850a4e9518Sgw 	/*
1086e14bb325SJeff Bonwick 	 * A similar issue exists for the L2ARC write thread until L2ARC 2.0.
10870a4e9518Sgw 	 */
1088e14bb325SJeff Bonwick 	if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux)
1089e14bb325SJeff Bonwick 		t = ZIO_TYPE_NULL;
10900a4e9518Sgw 
109180eb36f2SGeorge Wilson 	/*
109280eb36f2SGeorge Wilson 	 * If this is a high priority I/O, then use the high priority taskq.
109380eb36f2SGeorge Wilson 	 */
109480eb36f2SGeorge Wilson 	if (zio->io_priority == ZIO_PRIORITY_NOW &&
109580eb36f2SGeorge Wilson 	    spa->spa_zio_taskq[t][q + 1] != NULL)
109680eb36f2SGeorge Wilson 		q++;
109780eb36f2SGeorge Wilson 
109880eb36f2SGeorge Wilson 	ASSERT3U(q, <, ZIO_TASKQ_TYPES);
10995aeb9474SGarrett D'Amore 
11005aeb9474SGarrett D'Amore 	/*
11015aeb9474SGarrett D'Amore 	 * NB: We are assuming that the zio can only be dispatched
11025aeb9474SGarrett D'Amore 	 * to a single taskq at a time.  It would be a grievous error
11035aeb9474SGarrett D'Amore 	 * to dispatch the zio to another taskq at the same time.
11045aeb9474SGarrett D'Amore 	 */
11055aeb9474SGarrett D'Amore 	ASSERT(zio->io_tqent.tqent_next == NULL);
11065aeb9474SGarrett D'Amore 	taskq_dispatch_ent(spa->spa_zio_taskq[t][q],
11075aeb9474SGarrett D'Amore 	    (task_func_t *)zio_execute, zio, flags, &zio->io_tqent);
1108e14bb325SJeff Bonwick }
11090a4e9518Sgw 
1110e14bb325SJeff Bonwick static boolean_t
1111e14bb325SJeff Bonwick zio_taskq_member(zio_t *zio, enum zio_taskq_type q)
1112e14bb325SJeff Bonwick {
1113e14bb325SJeff Bonwick 	kthread_t *executor = zio->io_executor;
1114e14bb325SJeff Bonwick 	spa_t *spa = zio->io_spa;
11150a4e9518Sgw 
1116e14bb325SJeff Bonwick 	for (zio_type_t t = 0; t < ZIO_TYPES; t++)
1117e14bb325SJeff Bonwick 		if (taskq_member(spa->spa_zio_taskq[t][q], executor))
1118e14bb325SJeff Bonwick 			return (B_TRUE);
11190a4e9518Sgw 
1120e14bb325SJeff Bonwick 	return (B_FALSE);
1121e14bb325SJeff Bonwick }
1122e05725b1Sbonwick 
1123e14bb325SJeff Bonwick static int
1124e14bb325SJeff Bonwick zio_issue_async(zio_t *zio)
1125e14bb325SJeff Bonwick {
112635a5a358SJonathan Adams 	zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE);
1127e14bb325SJeff Bonwick 
1128e14bb325SJeff Bonwick 	return (ZIO_PIPELINE_STOP);
11290a4e9518Sgw }
11300a4e9518Sgw 
1131e14bb325SJeff Bonwick void
1132e14bb325SJeff Bonwick zio_interrupt(zio_t *zio)
11330a4e9518Sgw {
113435a5a358SJonathan Adams 	zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE);
1135e14bb325SJeff Bonwick }
11360a4e9518Sgw 
1137e14bb325SJeff Bonwick /*
1138e14bb325SJeff Bonwick  * Execute the I/O pipeline until one of the following occurs:
1139e14bb325SJeff Bonwick  * (1) the I/O completes; (2) the pipeline stalls waiting for
1140e14bb325SJeff Bonwick  * dependent child I/Os; (3) the I/O issues, so we're waiting
1141e14bb325SJeff Bonwick  * for an I/O completion interrupt; (4) the I/O is delegated by
1142e14bb325SJeff Bonwick  * vdev-level caching or aggregation; (5) the I/O is deferred
1143e14bb325SJeff Bonwick  * due to vdev-level queueing; (6) the I/O is handed off to
1144e14bb325SJeff Bonwick  * another thread.  In all cases, the pipeline stops whenever
1145e14bb325SJeff Bonwick  * there's no CPU work; it never burns a thread in cv_wait().
1146e14bb325SJeff Bonwick  *
1147e14bb325SJeff Bonwick  * There's no locking on io_stage because there's no legitimate way
1148e14bb325SJeff Bonwick  * for multiple threads to be attempting to process the same I/O.
1149e14bb325SJeff Bonwick  */
1150b24ab676SJeff Bonwick static zio_pipe_stage_t *zio_pipeline[];
11510a4e9518Sgw 
1152e14bb325SJeff Bonwick void
1153e14bb325SJeff Bonwick zio_execute(zio_t *zio)
1154e14bb325SJeff Bonwick {
1155e14bb325SJeff Bonwick 	zio->io_executor = curthread;
11560a4e9518Sgw 
1157e14bb325SJeff Bonwick 	while (zio->io_stage < ZIO_STAGE_DONE) {
1158b24ab676SJeff Bonwick 		enum zio_stage pipeline = zio->io_pipeline;
1159b24ab676SJeff Bonwick 		enum zio_stage stage = zio->io_stage;
1160e14bb325SJeff Bonwick 		int rv;
11610a4e9518Sgw 
1162e14bb325SJeff Bonwick 		ASSERT(!MUTEX_HELD(&zio->io_lock));
1163b24ab676SJeff Bonwick 		ASSERT(ISP2(stage));
1164b24ab676SJeff Bonwick 		ASSERT(zio->io_stall == NULL);
11650a4e9518Sgw 
1166b24ab676SJeff Bonwick 		do {
1167b24ab676SJeff Bonwick 			stage <<= 1;
1168b24ab676SJeff Bonwick 		} while ((stage & pipeline) == 0);
1169e14bb325SJeff Bonwick 
1170e14bb325SJeff Bonwick 		ASSERT(stage <= ZIO_STAGE_DONE);
11710a4e9518Sgw 
11720a4e9518Sgw 		/*
1173e14bb325SJeff Bonwick 		 * If we are in interrupt context and this pipeline stage
1174e14bb325SJeff Bonwick 		 * will grab a config lock that is held across I/O,
1175b24ab676SJeff Bonwick 		 * or may wait for an I/O that needs an interrupt thread
1176b24ab676SJeff Bonwick 		 * to complete, issue async to avoid deadlock.
117735a5a358SJonathan Adams 		 *
117835a5a358SJonathan Adams 		 * For VDEV_IO_START, we cut in line so that the io will
117935a5a358SJonathan Adams 		 * be sent to disk promptly.
11800a4e9518Sgw 		 */
1181b24ab676SJeff Bonwick 		if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL &&
1182e14bb325SJeff Bonwick 		    zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) {
118335a5a358SJonathan Adams 			boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ?
118435a5a358SJonathan Adams 			    zio_requeue_io_start_cut_in_line : B_FALSE;
118535a5a358SJonathan Adams 			zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut);
1186e14bb325SJeff Bonwick 			return;
11870a4e9518Sgw 		}
11880a4e9518Sgw 
1189e14bb325SJeff Bonwick 		zio->io_stage = stage;
1190b24ab676SJeff Bonwick 		rv = zio_pipeline[highbit(stage) - 1](zio);
11910a4e9518Sgw 
1192e14bb325SJeff Bonwick 		if (rv == ZIO_PIPELINE_STOP)
1193e14bb325SJeff Bonwick 			return;
11940a4e9518Sgw 
1195e14bb325SJeff Bonwick 		ASSERT(rv == ZIO_PIPELINE_CONTINUE);
1196e14bb325SJeff Bonwick 	}
11970a4e9518Sgw }
11980a4e9518Sgw 
1199e14bb325SJeff Bonwick /*
1200e14bb325SJeff Bonwick  * ==========================================================================
1201e14bb325SJeff Bonwick  * Initiate I/O, either sync or async
1202e14bb325SJeff Bonwick  * ==========================================================================
1203e14bb325SJeff Bonwick  */
1204e14bb325SJeff Bonwick int
1205e14bb325SJeff Bonwick zio_wait(zio_t *zio)
12060a4e9518Sgw {
1207e14bb325SJeff Bonwick 	int error;
12080a4e9518Sgw 
1209e14bb325SJeff Bonwick 	ASSERT(zio->io_stage == ZIO_STAGE_OPEN);
1210e14bb325SJeff Bonwick 	ASSERT(zio->io_executor == NULL);
12110a4e9518Sgw 
1212e14bb325SJeff Bonwick 	zio->io_waiter = curthread;
1213e05725b1Sbonwick 
1214e14bb325SJeff Bonwick 	zio_execute(zio);
12150a4e9518Sgw 
1216e14bb325SJeff Bonwick 	mutex_enter(&zio->io_lock);
1217e14bb325SJeff Bonwick 	while (zio->io_executor != NULL)
1218e14bb325SJeff Bonwick 		cv_wait(&zio->io_cv, &zio->io_lock);
1219e14bb325SJeff Bonwick 	mutex_exit(&zio->io_lock);
122032b87932Sek 
1221e14bb325SJeff Bonwick 	error = zio->io_error;
1222e14bb325SJeff Bonwick 	zio_destroy(zio);
122332b87932Sek 
1224e14bb325SJeff Bonwick 	return (error);
122532b87932Sek }
122632b87932Sek 
1227e14bb325SJeff Bonwick void
1228e14bb325SJeff Bonwick zio_nowait(zio_t *zio)
12290a4e9518Sgw {
1230e14bb325SJeff Bonwick 	ASSERT(zio->io_executor == NULL);
1231fa9e4066Sahrens 
1232a3f829aeSBill Moore 	if (zio->io_child_type == ZIO_CHILD_LOGICAL &&
1233a3f829aeSBill Moore 	    zio_unique_parent(zio) == NULL) {
1234ea8dc4b6Seschrock 		/*
1235e14bb325SJeff Bonwick 		 * This is a logical async I/O with no parent to wait for it.
123654d692b7SGeorge Wilson 		 * We add it to the spa_async_root_zio "Godfather" I/O which
123754d692b7SGeorge Wilson 		 * will ensure they complete prior to unloading the pool.
1238ea8dc4b6Seschrock 		 */
1239e14bb325SJeff Bonwick 		spa_t *spa = zio->io_spa;
124054d692b7SGeorge Wilson 
124154d692b7SGeorge Wilson 		zio_add_child(spa->spa_async_zio_root, zio);
1242e14bb325SJeff Bonwick 	}
1243ea8dc4b6Seschrock 
1244e14bb325SJeff Bonwick 	zio_execute(zio);
1245e14bb325SJeff Bonwick }
1246ea8dc4b6Seschrock 
1247e14bb325SJeff Bonwick /*
1248e14bb325SJeff Bonwick  * ==========================================================================
1249e14bb325SJeff Bonwick  * Reexecute or suspend/resume failed I/O
1250e14bb325SJeff Bonwick  * ==========================================================================
1251e14bb325SJeff Bonwick  */
1252fa9e4066Sahrens 
1253e14bb325SJeff Bonwick static void
1254e14bb325SJeff Bonwick zio_reexecute(zio_t *pio)
1255e14bb325SJeff Bonwick {
1256a3f829aeSBill Moore 	zio_t *cio, *cio_next;
1257a3f829aeSBill Moore 
1258a3f829aeSBill Moore 	ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL);
1259a3f829aeSBill Moore 	ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN);
1260f5383399SBill Moore 	ASSERT(pio->io_gang_leader == NULL);
1261f5383399SBill Moore 	ASSERT(pio->io_gang_tree == NULL);
1262e05725b1Sbonwick 
1263e14bb325SJeff Bonwick 	pio->io_flags = pio->io_orig_flags;
1264e14bb325SJeff Bonwick 	pio->io_stage = pio->io_orig_stage;
1265e14bb325SJeff Bonwick 	pio->io_pipeline = pio->io_orig_pipeline;
1266e14bb325SJeff Bonwick 	pio->io_reexecute = 0;
1267e14bb325SJeff Bonwick 	pio->io_error = 0;
1268a3f829aeSBill Moore 	for (int w = 0; w < ZIO_WAIT_TYPES; w++)
1269a3f829aeSBill Moore 		pio->io_state[w] = 0;
1270e14bb325SJeff Bonwick 	for (int c = 0; c < ZIO_CHILD_TYPES; c++)
1271e14bb325SJeff Bonwick 		pio->io_child_error[c] = 0;
12720a4e9518Sgw 
1273b24ab676SJeff Bonwick 	if (IO_IS_ALLOCATING(pio))
1274b24ab676SJeff Bonwick 		BP_ZERO(pio->io_bp);
1275d58459f4Sek 
1276e14bb325SJeff Bonwick 	/*
1277e14bb325SJeff Bonwick 	 * As we reexecute pio's children, new children could be created.
1278a3f829aeSBill Moore 	 * New children go to the head of pio's io_child_list, however,
1279e14bb325SJeff Bonwick 	 * so we will (correctly) not reexecute them.  The key is that
1280a3f829aeSBill Moore 	 * the remainder of pio's io_child_list, from 'cio_next' onward,
1281a3f829aeSBill Moore 	 * cannot be affected by any side effects of reexecuting 'cio'.
1282e14bb325SJeff Bonwick 	 */
1283a3f829aeSBill Moore 	for (cio = zio_walk_children(pio); cio != NULL; cio = cio_next) {
1284a3f829aeSBill Moore 		cio_next = zio_walk_children(pio);
1285e14bb325SJeff Bonwick 		mutex_enter(&pio->io_lock);
1286a3f829aeSBill Moore 		for (int w = 0; w < ZIO_WAIT_TYPES; w++)
1287a3f829aeSBill Moore 			pio->io_children[cio->io_child_type][w]++;
1288e14bb325SJeff Bonwick 		mutex_exit(&pio->io_lock);
1289a3f829aeSBill Moore 		zio_reexecute(cio);
1290fa9e4066Sahrens 	}
1291e05725b1Sbonwick 
1292e14bb325SJeff Bonwick 	/*
1293e14bb325SJeff Bonwick 	 * Now that all children have been reexecuted, execute the parent.
129454d692b7SGeorge Wilson 	 * We don't reexecute "The Godfather" I/O here as it's the
129554d692b7SGeorge Wilson 	 * responsibility of the caller to wait on him.
1296e14bb325SJeff Bonwick 	 */
129754d692b7SGeorge Wilson 	if (!(pio->io_flags & ZIO_FLAG_GODFATHER))
129854d692b7SGeorge Wilson 		zio_execute(pio);
12990a4e9518Sgw }
13000a4e9518Sgw 
1301e14bb325SJeff Bonwick void
1302e14bb325SJeff Bonwick zio_suspend(spa_t *spa, zio_t *zio)
13030a4e9518Sgw {
1304e14bb325SJeff Bonwick 	if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC)
1305e14bb325SJeff Bonwick 		fm_panic("Pool '%s' has encountered an uncorrectable I/O "
1306e14bb325SJeff Bonwick 		    "failure and the failure mode property for this pool "
1307e14bb325SJeff Bonwick 		    "is set to panic.", spa_name(spa));
13080a4e9518Sgw 
1309e14bb325SJeff Bonwick 	zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, NULL, 0, 0);
13100a4e9518Sgw 
1311e14bb325SJeff Bonwick 	mutex_enter(&spa->spa_suspend_lock);
1312fa9e4066Sahrens 
1313e14bb325SJeff Bonwick 	if (spa->spa_suspend_zio_root == NULL)
131454d692b7SGeorge Wilson 		spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL,
131554d692b7SGeorge Wilson 		    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
131654d692b7SGeorge Wilson 		    ZIO_FLAG_GODFATHER);
1317fa9e4066Sahrens 
1318e14bb325SJeff Bonwick 	spa->spa_suspended = B_TRUE;
1319fa9e4066Sahrens 
1320e14bb325SJeff Bonwick 	if (zio != NULL) {
132154d692b7SGeorge Wilson 		ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER));
1322e14bb325SJeff Bonwick 		ASSERT(zio != spa->spa_suspend_zio_root);
1323e14bb325SJeff Bonwick 		ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1324a3f829aeSBill Moore 		ASSERT(zio_unique_parent(zio) == NULL);
1325e14bb325SJeff Bonwick 		ASSERT(zio->io_stage == ZIO_STAGE_DONE);
1326e14bb325SJeff Bonwick 		zio_add_child(spa->spa_suspend_zio_root, zio);
1327e14bb325SJeff Bonwick 	}
1328fa9e4066Sahrens 
1329e14bb325SJeff Bonwick 	mutex_exit(&spa->spa_suspend_lock);
1330e14bb325SJeff Bonwick }
1331fa9e4066Sahrens 
133254d692b7SGeorge Wilson int
1333e14bb325SJeff Bonwick zio_resume(spa_t *spa)
1334e14bb325SJeff Bonwick {
133554d692b7SGeorge Wilson 	zio_t *pio;
1336fa9e4066Sahrens 
1337b3995adbSahrens 	/*
1338e14bb325SJeff Bonwick 	 * Reexecute all previously suspended i/o.
1339b3995adbSahrens 	 */
1340e14bb325SJeff Bonwick 	mutex_enter(&spa->spa_suspend_lock);
1341e14bb325SJeff Bonwick 	spa->spa_suspended = B_FALSE;
1342e14bb325SJeff Bonwick 	cv_broadcast(&spa->spa_suspend_cv);
1343e14bb325SJeff Bonwick 	pio = spa->spa_suspend_zio_root;
1344e14bb325SJeff Bonwick 	spa->spa_suspend_zio_root = NULL;
1345e14bb325SJeff Bonwick 	mutex_exit(&spa->spa_suspend_lock);
1346e14bb325SJeff Bonwick 
1347e14bb325SJeff Bonwick 	if (pio == NULL)
134854d692b7SGeorge Wilson 		return (0);
1349e14bb325SJeff Bonwick 
135054d692b7SGeorge Wilson 	zio_reexecute(pio);
135154d692b7SGeorge Wilson 	return (zio_wait(pio));
1352e14bb325SJeff Bonwick }
1353e14bb325SJeff Bonwick 
1354e14bb325SJeff Bonwick void
1355e14bb325SJeff Bonwick zio_resume_wait(spa_t *spa)
1356e14bb325SJeff Bonwick {
1357e14bb325SJeff Bonwick 	mutex_enter(&spa->spa_suspend_lock);
1358e14bb325SJeff Bonwick 	while (spa_suspended(spa))
1359e14bb325SJeff Bonwick 		cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock);
1360e14bb325SJeff Bonwick 	mutex_exit(&spa->spa_suspend_lock);
1361fa9e4066Sahrens }
1362fa9e4066Sahrens 
1363fa9e4066Sahrens /*
1364fa9e4066Sahrens  * ==========================================================================
1365e14bb325SJeff Bonwick  * Gang blocks.
1366e14bb325SJeff Bonwick  *
1367e14bb325SJeff Bonwick  * A gang block is a collection of small blocks that looks to the DMU
1368e14bb325SJeff Bonwick  * like one large block.  When zio_dva_allocate() cannot find a block
1369e14bb325SJeff Bonwick  * of the requested size, due to either severe fragmentation or the pool
1370e14bb325SJeff Bonwick  * being nearly full, it calls zio_write_gang_block() to construct the
1371e14bb325SJeff Bonwick  * block from smaller fragments.
1372e14bb325SJeff Bonwick  *
1373e14bb325SJeff Bonwick  * A gang block consists of a gang header (zio_gbh_phys_t) and up to
1374e14bb325SJeff Bonwick  * three (SPA_GBH_NBLKPTRS) gang members.  The gang header is just like
1375e14bb325SJeff Bonwick  * an indirect block: it's an array of block pointers.  It consumes
1376e14bb325SJeff Bonwick  * only one sector and hence is allocatable regardless of fragmentation.
1377e14bb325SJeff Bonwick  * The gang header's bps point to its gang members, which hold the data.
1378e14bb325SJeff Bonwick  *
1379e14bb325SJeff Bonwick  * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg>
1380e14bb325SJeff Bonwick  * as the verifier to ensure uniqueness of the SHA256 checksum.
1381e14bb325SJeff Bonwick  * Critically, the gang block bp's blk_cksum is the checksum of the data,
1382e14bb325SJeff Bonwick  * not the gang header.  This ensures that data block signatures (needed for
1383e14bb325SJeff Bonwick  * deduplication) are independent of how the block is physically stored.
1384e14bb325SJeff Bonwick  *
1385e14bb325SJeff Bonwick  * Gang blocks can be nested: a gang member may itself be a gang block.
1386e14bb325SJeff Bonwick  * Thus every gang block is a tree in which root and all interior nodes are
1387e14bb325SJeff Bonwick  * gang headers, and the leaves are normal blocks that contain user data.
1388e14bb325SJeff Bonwick  * The root of the gang tree is called the gang leader.
1389e14bb325SJeff Bonwick  *
1390e14bb325SJeff Bonwick  * To perform any operation (read, rewrite, free, claim) on a gang block,
1391e14bb325SJeff Bonwick  * zio_gang_assemble() first assembles the gang tree (minus data leaves)
1392e14bb325SJeff Bonwick  * in the io_gang_tree field of the original logical i/o by recursively
1393e14bb325SJeff Bonwick  * reading the gang leader and all gang headers below it.  This yields
1394e14bb325SJeff Bonwick  * an in-core tree containing the contents of every gang header and the
1395e14bb325SJeff Bonwick  * bps for every constituent of the gang block.
1396e14bb325SJeff Bonwick  *
1397e14bb325SJeff Bonwick  * With the gang tree now assembled, zio_gang_issue() just walks the gang tree
1398e14bb325SJeff Bonwick  * and invokes a callback on each bp.  To free a gang block, zio_gang_issue()
1399e14bb325SJeff Bonwick  * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp.
1400e14bb325SJeff Bonwick  * zio_claim_gang() provides a similarly trivial wrapper for zio_claim().
1401e14bb325SJeff Bonwick  * zio_read_gang() is a wrapper around zio_read() that omits reading gang
1402e14bb325SJeff Bonwick  * headers, since we already have those in io_gang_tree.  zio_rewrite_gang()
1403e14bb325SJeff Bonwick  * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite()
1404e14bb325SJeff Bonwick  * of the gang header plus zio_checksum_compute() of the data to update the
1405e14bb325SJeff Bonwick  * gang header's blk_cksum as described above.
1406e14bb325SJeff Bonwick  *
1407e14bb325SJeff Bonwick  * The two-phase assemble/issue model solves the problem of partial failure --
1408e14bb325SJeff Bonwick  * what if you'd freed part of a gang block but then couldn't read the
1409e14bb325SJeff Bonwick  * gang header for another part?  Assembling the entire gang tree first
1410e14bb325SJeff Bonwick  * ensures that all the necessary gang header I/O has succeeded before
1411e14bb325SJeff Bonwick  * starting the actual work of free, claim, or write.  Once the gang tree
1412e14bb325SJeff Bonwick  * is assembled, free and claim are in-memory operations that cannot fail.
1413e14bb325SJeff Bonwick  *
1414e14bb325SJeff Bonwick  * In the event that a gang write fails, zio_dva_unallocate() walks the
1415e14bb325SJeff Bonwick  * gang tree to immediately free (i.e. insert back into the space map)
1416e14bb325SJeff Bonwick  * everything we've allocated.  This ensures that we don't get ENOSPC
1417e14bb325SJeff Bonwick  * errors during repeated suspend/resume cycles due to a flaky device.
1418e14bb325SJeff Bonwick  *
1419e14bb325SJeff Bonwick  * Gang rewrites only happen during sync-to-convergence.  If we can't assemble
1420e14bb325SJeff Bonwick  * the gang tree, we won't modify the block, so we can safely defer the free
1421e14bb325SJeff Bonwick  * (knowing that the block is still intact).  If we *can* assemble the gang
1422e14bb325SJeff Bonwick  * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free
1423e14bb325SJeff Bonwick  * each constituent bp and we can allocate a new block on the next sync pass.
1424e14bb325SJeff Bonwick  *
1425e14bb325SJeff Bonwick  * In all cases, the gang tree allows complete recovery from partial failure.
1426fa9e4066Sahrens  * ==========================================================================
1427fa9e4066Sahrens  */
1428e14bb325SJeff Bonwick 
1429e14bb325SJeff Bonwick static zio_t *
1430e14bb325SJeff Bonwick zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data)
1431fa9e4066Sahrens {
1432e14bb325SJeff Bonwick 	if (gn != NULL)
1433e14bb325SJeff Bonwick 		return (pio);
1434fa9e4066Sahrens 
1435e14bb325SJeff Bonwick 	return (zio_read(pio, pio->io_spa, bp, data, BP_GET_PSIZE(bp),
1436e14bb325SJeff Bonwick 	    NULL, NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio),
1437e14bb325SJeff Bonwick 	    &pio->io_bookmark));
1438e14bb325SJeff Bonwick }
1439e14bb325SJeff Bonwick 
1440e14bb325SJeff Bonwick zio_t *
1441e14bb325SJeff Bonwick zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data)
1442e14bb325SJeff Bonwick {
1443e14bb325SJeff Bonwick 	zio_t *zio;
1444e14bb325SJeff Bonwick 
1445e14bb325SJeff Bonwick 	if (gn != NULL) {
1446e14bb325SJeff Bonwick 		zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp,
1447e14bb325SJeff Bonwick 		    gn->gn_gbh, SPA_GANGBLOCKSIZE, NULL, NULL, pio->io_priority,
1448e14bb325SJeff Bonwick 		    ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
1449fa9e4066Sahrens 		/*
1450e14bb325SJeff Bonwick 		 * As we rewrite each gang header, the pipeline will compute
1451e14bb325SJeff Bonwick 		 * a new gang block header checksum for it; but no one will
1452e14bb325SJeff Bonwick 		 * compute a new data checksum, so we do that here.  The one
1453e14bb325SJeff Bonwick 		 * exception is the gang leader: the pipeline already computed
1454e14bb325SJeff Bonwick 		 * its data checksum because that stage precedes gang assembly.
1455e14bb325SJeff Bonwick 		 * (Presently, nothing actually uses interior data checksums;
1456e14bb325SJeff Bonwick 		 * this is just good hygiene.)
1457fa9e4066Sahrens 		 */
1458f5383399SBill Moore 		if (gn != pio->io_gang_leader->io_gang_tree) {
1459e14bb325SJeff Bonwick 			zio_checksum_compute(zio, BP_GET_CHECKSUM(bp),
1460e14bb325SJeff Bonwick 			    data, BP_GET_PSIZE(bp));
1461e14bb325SJeff Bonwick 		}
1462b24ab676SJeff Bonwick 		/*
1463b24ab676SJeff Bonwick 		 * If we are here to damage data for testing purposes,
1464b24ab676SJeff Bonwick 		 * leave the GBH alone so that we can detect the damage.
1465b24ab676SJeff Bonwick 		 */
1466b24ab676SJeff Bonwick 		if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE)
1467b24ab676SJeff Bonwick 			zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES;
1468fa9e4066Sahrens 	} else {
1469e14bb325SJeff Bonwick 		zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp,
1470e14bb325SJeff Bonwick 		    data, BP_GET_PSIZE(bp), NULL, NULL, pio->io_priority,
1471e14bb325SJeff Bonwick 		    ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
1472fa9e4066Sahrens 	}
1473fa9e4066Sahrens 
1474e14bb325SJeff Bonwick 	return (zio);
1475e14bb325SJeff Bonwick }
1476fa9e4066Sahrens 
1477e14bb325SJeff Bonwick /* ARGSUSED */
1478e14bb325SJeff Bonwick zio_t *
1479e14bb325SJeff Bonwick zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data)
1480e14bb325SJeff Bonwick {
1481b24ab676SJeff Bonwick 	return (zio_free_sync(pio, pio->io_spa, pio->io_txg, bp,
1482b24ab676SJeff Bonwick 	    ZIO_GANG_CHILD_FLAGS(pio)));
1483fa9e4066Sahrens }
1484fa9e4066Sahrens 
1485e14bb325SJeff Bonwick /* ARGSUSED */
1486e14bb325SJeff Bonwick zio_t *
1487e14bb325SJeff Bonwick zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data)
1488fa9e4066Sahrens {
1489e14bb325SJeff Bonwick 	return (zio_claim(pio, pio->io_spa, pio->io_txg, bp,
1490e14bb325SJeff Bonwick 	    NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio)));
1491e14bb325SJeff Bonwick }
1492fa9e4066Sahrens 
1493e14bb325SJeff Bonwick static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = {
1494e14bb325SJeff Bonwick 	NULL,
1495e14bb325SJeff Bonwick 	zio_read_gang,
1496e14bb325SJeff Bonwick 	zio_rewrite_gang,
1497e14bb325SJeff Bonwick 	zio_free_gang,
1498e14bb325SJeff Bonwick 	zio_claim_gang,
1499e14bb325SJeff Bonwick 	NULL
1500e14bb325SJeff Bonwick };
1501fa9e4066Sahrens 
1502e14bb325SJeff Bonwick static void zio_gang_tree_assemble_done(zio_t *zio);
1503fa9e4066Sahrens 
1504e14bb325SJeff Bonwick static zio_gang_node_t *
1505e14bb325SJeff Bonwick zio_gang_node_alloc(zio_gang_node_t **gnpp)
1506e14bb325SJeff Bonwick {
1507e14bb325SJeff Bonwick 	zio_gang_node_t *gn;
1508fa9e4066Sahrens 
1509e14bb325SJeff Bonwick 	ASSERT(*gnpp == NULL);
1510fa9e4066Sahrens 
1511e14bb325SJeff Bonwick 	gn = kmem_zalloc(sizeof (*gn), KM_SLEEP);
1512e14bb325SJeff Bonwick 	gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE);
1513e14bb325SJeff Bonwick 	*gnpp = gn;
1514e14bb325SJeff Bonwick 
1515e14bb325SJeff Bonwick 	return (gn);
1516fa9e4066Sahrens }
1517fa9e4066Sahrens 
1518fa9e4066Sahrens static void
1519e14bb325SJeff Bonwick zio_gang_node_free(zio_gang_node_t **gnpp)
1520fa9e4066Sahrens {
1521e14bb325SJeff Bonwick 	zio_gang_node_t *gn = *gnpp;
1522fa9e4066Sahrens 
1523e14bb325SJeff Bonwick 	for (int g = 0; g < SPA_GBH_NBLKPTRS; g++)
1524e14bb325SJeff Bonwick 		ASSERT(gn->gn_child[g] == NULL);
1525e14bb325SJeff Bonwick 
1526e14bb325SJeff Bonwick 	zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE);
1527e14bb325SJeff Bonwick 	kmem_free(gn, sizeof (*gn));
1528e14bb325SJeff Bonwick 	*gnpp = NULL;
1529fa9e4066Sahrens }
1530fa9e4066Sahrens 
1531e14bb325SJeff Bonwick static void
1532e14bb325SJeff Bonwick zio_gang_tree_free(zio_gang_node_t **gnpp)
1533fa9e4066Sahrens {
1534e14bb325SJeff Bonwick 	zio_gang_node_t *gn = *gnpp;
1535fa9e4066Sahrens 
1536e14bb325SJeff Bonwick 	if (gn == NULL)
1537e14bb325SJeff Bonwick 		return;
1538fa9e4066Sahrens 
1539e14bb325SJeff Bonwick 	for (int g = 0; g < SPA_GBH_NBLKPTRS; g++)
1540e14bb325SJeff Bonwick 		zio_gang_tree_free(&gn->gn_child[g]);
1541fa9e4066Sahrens 
1542e14bb325SJeff Bonwick 	zio_gang_node_free(gnpp);
1543fa9e4066Sahrens }
1544fa9e4066Sahrens 
1545e14bb325SJeff Bonwick static void
1546f5383399SBill Moore zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp)
1547fa9e4066Sahrens {
1548e14bb325SJeff Bonwick 	zio_gang_node_t *gn = zio_gang_node_alloc(gnpp);
1549e14bb325SJeff Bonwick 
1550f5383399SBill Moore 	ASSERT(gio->io_gang_leader == gio);
1551e14bb325SJeff Bonwick 	ASSERT(BP_IS_GANG(bp));
1552fa9e4066Sahrens 
1553f5383399SBill Moore 	zio_nowait(zio_read(gio, gio->io_spa, bp, gn->gn_gbh,
1554e14bb325SJeff Bonwick 	    SPA_GANGBLOCKSIZE, zio_gang_tree_assemble_done, gn,
1555f5383399SBill Moore 	    gio->io_priority, ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark));
1556e14bb325SJeff Bonwick }
1557fa9e4066Sahrens 
1558e14bb325SJeff Bonwick static void
1559e14bb325SJeff Bonwick zio_gang_tree_assemble_done(zio_t *zio)
1560e14bb325SJeff Bonwick {
1561f5383399SBill Moore 	zio_t *gio = zio->io_gang_leader;
1562e14bb325SJeff Bonwick 	zio_gang_node_t *gn = zio->io_private;
1563e14bb325SJeff Bonwick 	blkptr_t *bp = zio->io_bp;
1564fa9e4066Sahrens 
1565f5383399SBill Moore 	ASSERT(gio == zio_unique_parent(zio));
1566b24ab676SJeff Bonwick 	ASSERT(zio->io_child_count == 0);
1567fa9e4066Sahrens 
1568e14bb325SJeff Bonwick 	if (zio->io_error)
1569e14bb325SJeff Bonwick 		return;
1570fa9e4066Sahrens 
1571e14bb325SJeff Bonwick 	if (BP_SHOULD_BYTESWAP(bp))
1572e14bb325SJeff Bonwick 		byteswap_uint64_array(zio->io_data, zio->io_size);
1573fa9e4066Sahrens 
1574e14bb325SJeff Bonwick 	ASSERT(zio->io_data == gn->gn_gbh);
1575e14bb325SJeff Bonwick 	ASSERT(zio->io_size == SPA_GANGBLOCKSIZE);
15766e1f5caaSNeil Perrin 	ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC);
1577e05725b1Sbonwick 
1578e14bb325SJeff Bonwick 	for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
1579e14bb325SJeff Bonwick 		blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g];
1580e14bb325SJeff Bonwick 		if (!BP_IS_GANG(gbp))
1581e14bb325SJeff Bonwick 			continue;
1582f5383399SBill Moore 		zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]);
1583e14bb325SJeff Bonwick 	}
1584fa9e4066Sahrens }
1585fa9e4066Sahrens 
1586e14bb325SJeff Bonwick static void
1587e14bb325SJeff Bonwick zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, void *data)
1588fa9e4066Sahrens {
1589f5383399SBill Moore 	zio_t *gio = pio->io_gang_leader;
1590e14bb325SJeff Bonwick 	zio_t *zio;
1591fa9e4066Sahrens 
1592e14bb325SJeff Bonwick 	ASSERT(BP_IS_GANG(bp) == !!gn);
1593f5383399SBill Moore 	ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp));
1594f5383399SBill Moore 	ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree);
1595fa9e4066Sahrens 
1596e14bb325SJeff Bonwick 	/*
1597e14bb325SJeff Bonwick 	 * If you're a gang header, your data is in gn->gn_gbh.
1598e14bb325SJeff Bonwick 	 * If you're a gang member, your data is in 'data' and gn == NULL.
1599e14bb325SJeff Bonwick 	 */
1600f5383399SBill Moore 	zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data);
1601fa9e4066Sahrens 
1602e14bb325SJeff Bonwick 	if (gn != NULL) {
16036e1f5caaSNeil Perrin 		ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC);
1604fa9e4066Sahrens 
1605e14bb325SJeff Bonwick 		for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
1606e14bb325SJeff Bonwick 			blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g];
1607e14bb325SJeff Bonwick 			if (BP_IS_HOLE(gbp))
1608e14bb325SJeff Bonwick 				continue;
1609e14bb325SJeff Bonwick 			zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data);
1610e14bb325SJeff Bonwick 			data = (char *)data + BP_GET_PSIZE(gbp);
1611e14bb325SJeff Bonwick 		}
1612fa9e4066Sahrens 	}
1613fa9e4066Sahrens 
1614f5383399SBill Moore 	if (gn == gio->io_gang_tree)
1615f5383399SBill Moore 		ASSERT3P((char *)gio->io_data + gio->io_size, ==, data);
1616e05725b1Sbonwick 
1617e14bb325SJeff Bonwick 	if (zio != pio)
1618e14bb325SJeff Bonwick 		zio_nowait(zio);
1619fa9e4066Sahrens }
1620fa9e4066Sahrens 
1621e05725b1Sbonwick static int
1622e14bb325SJeff Bonwick zio_gang_assemble(zio_t *zio)
1623fa9e4066Sahrens {
1624e14bb325SJeff Bonwick 	blkptr_t *bp = zio->io_bp;
1625fa9e4066Sahrens 
1626f5383399SBill Moore 	ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL);
1627f5383399SBill Moore 	ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
1628f5383399SBill Moore 
1629f5383399SBill Moore 	zio->io_gang_leader = zio;
1630fa9e4066Sahrens 
1631e14bb325SJeff Bonwick 	zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree);
1632e05725b1Sbonwick 
1633e05725b1Sbonwick 	return (ZIO_PIPELINE_CONTINUE);
1634fa9e4066Sahrens }
1635fa9e4066Sahrens 
1636e05725b1Sbonwick static int
1637e14bb325SJeff Bonwick zio_gang_issue(zio_t *zio)
1638fa9e4066Sahrens {
1639e14bb325SJeff Bonwick 	blkptr_t *bp = zio->io_bp;
1640fa9e4066Sahrens 
1641e14bb325SJeff Bonwick 	if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE))
1642e14bb325SJeff Bonwick 		return (ZIO_PIPELINE_STOP);
1643fa9e4066Sahrens 
1644f5383399SBill Moore 	ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio);
1645f5383399SBill Moore 	ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
1646fa9e4066Sahrens 
1647e14bb325SJeff Bonwick 	if (zio->io_child_error[ZIO_CHILD_GANG] == 0)
1648f5383399SBill Moore 		zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_data);
1649e14bb325SJeff Bonwick 	else
1650f5383399SBill Moore 		zio_gang_tree_free(&zio->io_gang_tree);
1651fa9e4066Sahrens 
1652e14bb325SJeff Bonwick 	zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1653e05725b1Sbonwick 
1654e05725b1Sbonwick 	return (ZIO_PIPELINE_CONTINUE);
1655fa9e4066Sahrens }
1656fa9e4066Sahrens 
1657fa9e4066Sahrens static void
1658e14bb325SJeff Bonwick zio_write_gang_member_ready(zio_t *zio)
1659fa9e4066Sahrens {
1660a3f829aeSBill Moore 	zio_t *pio = zio_unique_parent(zio);
1661f5383399SBill Moore 	zio_t *gio = zio->io_gang_leader;
166244cd46caSbillm 	dva_t *cdva = zio->io_bp->blk_dva;
166344cd46caSbillm 	dva_t *pdva = pio->io_bp->blk_dva;
1664fa9e4066Sahrens 	uint64_t asize;
1665fa9e4066Sahrens 
1666e14bb325SJeff Bonwick 	if (BP_IS_HOLE(zio->io_bp))
1667e14bb325SJeff Bonwick 		return;
1668e14bb325SJeff Bonwick 
1669e14bb325SJeff Bonwick 	ASSERT(BP_IS_HOLE(&zio->io_bp_orig));
1670e14bb325SJeff Bonwick 
1671e14bb325SJeff Bonwick 	ASSERT(zio->io_child_type == ZIO_CHILD_GANG);
1672b24ab676SJeff Bonwick 	ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies);
1673b24ab676SJeff Bonwick 	ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp));
1674b24ab676SJeff Bonwick 	ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp));
167544cd46caSbillm 	ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp));
1676fa9e4066Sahrens 
1677fa9e4066Sahrens 	mutex_enter(&pio->io_lock);
1678e14bb325SJeff Bonwick 	for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) {
167944cd46caSbillm 		ASSERT(DVA_GET_GANG(&pdva[d]));
168044cd46caSbillm 		asize = DVA_GET_ASIZE(&pdva[d]);
168144cd46caSbillm 		asize += DVA_GET_ASIZE(&cdva[d]);
168244cd46caSbillm 		DVA_SET_ASIZE(&pdva[d], asize);
168344cd46caSbillm 	}
1684fa9e4066Sahrens 	mutex_exit(&pio->io_lock);
1685fa9e4066Sahrens }
1686fa9e4066Sahrens 
16870a4e9518Sgw static int
1688e14bb325SJeff Bonwick zio_write_gang_block(zio_t *pio)
1689fa9e4066Sahrens {
1690e14bb325SJeff Bonwick 	spa_t *spa = pio->io_spa;
1691e14bb325SJeff Bonwick 	blkptr_t *bp = pio->io_bp;
1692f5383399SBill Moore 	zio_t *gio = pio->io_gang_leader;
1693e14bb325SJeff Bonwick 	zio_t *zio;
1694e14bb325SJeff Bonwick 	zio_gang_node_t *gn, **gnpp;
1695fa9e4066Sahrens 	zio_gbh_phys_t *gbh;
1696e14bb325SJeff Bonwick 	uint64_t txg = pio->io_txg;
1697e14bb325SJeff Bonwick 	uint64_t resid = pio->io_size;
1698e14bb325SJeff Bonwick 	uint64_t lsize;
1699b24ab676SJeff Bonwick 	int copies = gio->io_prop.zp_copies;
1700b24ab676SJeff Bonwick 	int gbh_copies = MIN(copies + 1, spa_max_replication(spa));
1701e14bb325SJeff Bonwick 	zio_prop_t zp;
1702fa9e4066Sahrens 	int error;
1703fa9e4066Sahrens 
1704b24ab676SJeff Bonwick 	error = metaslab_alloc(spa, spa_normal_class(spa), SPA_GANGBLOCKSIZE,
1705b24ab676SJeff Bonwick 	    bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp,
1706e14bb325SJeff Bonwick 	    METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER);
1707e05725b1Sbonwick 	if (error) {
1708e14bb325SJeff Bonwick 		pio->io_error = error;
1709e05725b1Sbonwick 		return (ZIO_PIPELINE_CONTINUE);
1710e05725b1Sbonwick 	}
1711fa9e4066Sahrens 
1712f5383399SBill Moore 	if (pio == gio) {
1713f5383399SBill Moore 		gnpp = &gio->io_gang_tree;
1714e14bb325SJeff Bonwick 	} else {
1715e14bb325SJeff Bonwick 		gnpp = pio->io_private;
1716e14bb325SJeff Bonwick 		ASSERT(pio->io_ready == zio_write_gang_member_ready);
1717fa9e4066Sahrens 	}
1718fa9e4066Sahrens 
1719e14bb325SJeff Bonwick 	gn = zio_gang_node_alloc(gnpp);
1720e14bb325SJeff Bonwick 	gbh = gn->gn_gbh;
1721e14bb325SJeff Bonwick 	bzero(gbh, SPA_GANGBLOCKSIZE);
1722fa9e4066Sahrens 
1723e14bb325SJeff Bonwick 	/*
1724e14bb325SJeff Bonwick 	 * Create the gang header.
1725e14bb325SJeff Bonwick 	 */
1726e14bb325SJeff Bonwick 	zio = zio_rewrite(pio, spa, txg, bp, gbh, SPA_GANGBLOCKSIZE, NULL, NULL,
1727e14bb325SJeff Bonwick 	    pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
1728fa9e4066Sahrens 
1729e14bb325SJeff Bonwick 	/*
1730e14bb325SJeff Bonwick 	 * Create and nowait the gang children.
1731e14bb325SJeff Bonwick 	 */
1732e14bb325SJeff Bonwick 	for (int g = 0; resid != 0; resid -= lsize, g++) {
1733e14bb325SJeff Bonwick 		lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g),
1734e14bb325SJeff Bonwick 		    SPA_MINBLOCKSIZE);
1735e14bb325SJeff Bonwick 		ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid);
1736e14bb325SJeff Bonwick 
1737f5383399SBill Moore 		zp.zp_checksum = gio->io_prop.zp_checksum;
1738e14bb325SJeff Bonwick 		zp.zp_compress = ZIO_COMPRESS_OFF;
1739e14bb325SJeff Bonwick 		zp.zp_type = DMU_OT_NONE;
1740e14bb325SJeff Bonwick 		zp.zp_level = 0;
1741b24ab676SJeff Bonwick 		zp.zp_copies = gio->io_prop.zp_copies;
1742b24ab676SJeff Bonwick 		zp.zp_dedup = 0;
1743b24ab676SJeff Bonwick 		zp.zp_dedup_verify = 0;
1744e14bb325SJeff Bonwick 
1745e14bb325SJeff Bonwick 		zio_nowait(zio_write(zio, spa, txg, &gbh->zg_blkptr[g],
1746e14bb325SJeff Bonwick 		    (char *)pio->io_data + (pio->io_size - resid), lsize, &zp,
1747e14bb325SJeff Bonwick 		    zio_write_gang_member_ready, NULL, &gn->gn_child[g],
1748e14bb325SJeff Bonwick 		    pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio),
1749e14bb325SJeff Bonwick 		    &pio->io_bookmark));
1750e14bb325SJeff Bonwick 	}
1751e05725b1Sbonwick 
175244cd46caSbillm 	/*
1753e14bb325SJeff Bonwick 	 * Set pio's pipeline to just wait for zio to finish.
175444cd46caSbillm 	 */
1755e14bb325SJeff Bonwick 	pio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1756e14bb325SJeff Bonwick 
1757e14bb325SJeff Bonwick 	zio_nowait(zio);
1758e14bb325SJeff Bonwick 
1759e14bb325SJeff Bonwick 	return (ZIO_PIPELINE_CONTINUE);
1760fa9e4066Sahrens }
1761fa9e4066Sahrens 
1762fa9e4066Sahrens /*
1763fa9e4066Sahrens  * ==========================================================================
1764b24ab676SJeff Bonwick  * Dedup
1765fa9e4066Sahrens  * ==========================================================================
1766fa9e4066Sahrens  */
1767b24ab676SJeff Bonwick static void
1768b24ab676SJeff Bonwick zio_ddt_child_read_done(zio_t *zio)
1769b24ab676SJeff Bonwick {
1770b24ab676SJeff Bonwick 	blkptr_t *bp = zio->io_bp;
1771b24ab676SJeff Bonwick 	ddt_entry_t *dde = zio->io_private;
1772b24ab676SJeff Bonwick 	ddt_phys_t *ddp;
1773b24ab676SJeff Bonwick 	zio_t *pio = zio_unique_parent(zio);
1774b24ab676SJeff Bonwick 
1775b24ab676SJeff Bonwick 	mutex_enter(&pio->io_lock);
1776b24ab676SJeff Bonwick 	ddp = ddt_phys_select(dde, bp);
1777b24ab676SJeff Bonwick 	if (zio->io_error == 0)
1778b24ab676SJeff Bonwick 		ddt_phys_clear(ddp);	/* this ddp doesn't need repair */
1779b24ab676SJeff Bonwick 	if (zio->io_error == 0 && dde->dde_repair_data == NULL)
1780b24ab676SJeff Bonwick 		dde->dde_repair_data = zio->io_data;
1781b24ab676SJeff Bonwick 	else
1782b24ab676SJeff Bonwick 		zio_buf_free(zio->io_data, zio->io_size);
1783b24ab676SJeff Bonwick 	mutex_exit(&pio->io_lock);
1784b24ab676SJeff Bonwick }
1785b24ab676SJeff Bonwick 
1786b24ab676SJeff Bonwick static int
1787b24ab676SJeff Bonwick zio_ddt_read_start(zio_t *zio)
1788b24ab676SJeff Bonwick {
1789b24ab676SJeff Bonwick 	blkptr_t *bp = zio->io_bp;
1790b24ab676SJeff Bonwick 
1791b24ab676SJeff Bonwick 	ASSERT(BP_GET_DEDUP(bp));
1792b24ab676SJeff Bonwick 	ASSERT(BP_GET_PSIZE(bp) == zio->io_size);
1793b24ab676SJeff Bonwick 	ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1794b24ab676SJeff Bonwick 
1795b24ab676SJeff Bonwick 	if (zio->io_child_error[ZIO_CHILD_DDT]) {
1796b24ab676SJeff Bonwick 		ddt_t *ddt = ddt_select(zio->io_spa, bp);
1797b24ab676SJeff Bonwick 		ddt_entry_t *dde = ddt_repair_start(ddt, bp);
1798b24ab676SJeff Bonwick 		ddt_phys_t *ddp = dde->dde_phys;
1799b24ab676SJeff Bonwick 		ddt_phys_t *ddp_self = ddt_phys_select(dde, bp);
1800b24ab676SJeff Bonwick 		blkptr_t blk;
1801b24ab676SJeff Bonwick 
1802b24ab676SJeff Bonwick 		ASSERT(zio->io_vsd == NULL);
1803b24ab676SJeff Bonwick 		zio->io_vsd = dde;
1804b24ab676SJeff Bonwick 
1805b24ab676SJeff Bonwick 		if (ddp_self == NULL)
1806b24ab676SJeff Bonwick 			return (ZIO_PIPELINE_CONTINUE);
1807b24ab676SJeff Bonwick 
1808b24ab676SJeff Bonwick 		for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
1809b24ab676SJeff Bonwick 			if (ddp->ddp_phys_birth == 0 || ddp == ddp_self)
1810b24ab676SJeff Bonwick 				continue;
1811bbfd46c4SJeff Bonwick 			ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp,
1812bbfd46c4SJeff Bonwick 			    &blk);
1813b24ab676SJeff Bonwick 			zio_nowait(zio_read(zio, zio->io_spa, &blk,
1814b24ab676SJeff Bonwick 			    zio_buf_alloc(zio->io_size), zio->io_size,
1815b24ab676SJeff Bonwick 			    zio_ddt_child_read_done, dde, zio->io_priority,
1816b24ab676SJeff Bonwick 			    ZIO_DDT_CHILD_FLAGS(zio) | ZIO_FLAG_DONT_PROPAGATE,
1817b24ab676SJeff Bonwick 			    &zio->io_bookmark));
1818b24ab676SJeff Bonwick 		}
1819b24ab676SJeff Bonwick 		return (ZIO_PIPELINE_CONTINUE);
1820b24ab676SJeff Bonwick 	}
1821b24ab676SJeff Bonwick 
1822b24ab676SJeff Bonwick 	zio_nowait(zio_read(zio, zio->io_spa, bp,
1823b24ab676SJeff Bonwick 	    zio->io_data, zio->io_size, NULL, NULL, zio->io_priority,
1824b24ab676SJeff Bonwick 	    ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark));
1825b24ab676SJeff Bonwick 
1826b24ab676SJeff Bonwick 	return (ZIO_PIPELINE_CONTINUE);
1827b24ab676SJeff Bonwick }
1828e14bb325SJeff Bonwick 
1829b24ab676SJeff Bonwick static int
1830b24ab676SJeff Bonwick zio_ddt_read_done(zio_t *zio)
1831b24ab676SJeff Bonwick {
1832b24ab676SJeff Bonwick 	blkptr_t *bp = zio->io_bp;
1833b24ab676SJeff Bonwick 
1834b24ab676SJeff Bonwick 	if (zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE))
1835b24ab676SJeff Bonwick 		return (ZIO_PIPELINE_STOP);
1836b24ab676SJeff Bonwick 
1837b24ab676SJeff Bonwick 	ASSERT(BP_GET_DEDUP(bp));
1838b24ab676SJeff Bonwick 	ASSERT(BP_GET_PSIZE(bp) == zio->io_size);
1839b24ab676SJeff Bonwick 	ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1840b24ab676SJeff Bonwick 
1841b24ab676SJeff Bonwick 	if (zio->io_child_error[ZIO_CHILD_DDT]) {
1842b24ab676SJeff Bonwick 		ddt_t *ddt = ddt_select(zio->io_spa, bp);
1843b24ab676SJeff Bonwick 		ddt_entry_t *dde = zio->io_vsd;
1844b24ab676SJeff Bonwick 		if (ddt == NULL) {
1845b16da2e2SGeorge Wilson 			ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE);
1846b24ab676SJeff Bonwick 			return (ZIO_PIPELINE_CONTINUE);
1847b24ab676SJeff Bonwick 		}
1848b24ab676SJeff Bonwick 		if (dde == NULL) {
1849b24ab676SJeff Bonwick 			zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1;
185035a5a358SJonathan Adams 			zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE);
1851b24ab676SJeff Bonwick 			return (ZIO_PIPELINE_STOP);
1852b24ab676SJeff Bonwick 		}
1853b24ab676SJeff Bonwick 		if (dde->dde_repair_data != NULL) {
1854b24ab676SJeff Bonwick 			bcopy(dde->dde_repair_data, zio->io_data, zio->io_size);
1855b24ab676SJeff Bonwick 			zio->io_child_error[ZIO_CHILD_DDT] = 0;
1856b24ab676SJeff Bonwick 		}
1857b24ab676SJeff Bonwick 		ddt_repair_done(ddt, dde);
1858b24ab676SJeff Bonwick 		zio->io_vsd = NULL;
1859b24ab676SJeff Bonwick 	}
1860b24ab676SJeff Bonwick 
1861b24ab676SJeff Bonwick 	ASSERT(zio->io_vsd == NULL);
1862b24ab676SJeff Bonwick 
1863b24ab676SJeff Bonwick 	return (ZIO_PIPELINE_CONTINUE);
1864b24ab676SJeff Bonwick }
1865b24ab676SJeff Bonwick 
1866b24ab676SJeff Bonwick static boolean_t
1867b24ab676SJeff Bonwick zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde)
1868b24ab676SJeff Bonwick {
1869b24ab676SJeff Bonwick 	spa_t *spa = zio->io_spa;
1870b24ab676SJeff Bonwick 
1871b24ab676SJeff Bonwick 	/*
1872b24ab676SJeff Bonwick 	 * Note: we compare the original data, not the transformed data,
1873b24ab676SJeff Bonwick 	 * because when zio->io_bp is an override bp, we will not have
1874b24ab676SJeff Bonwick 	 * pushed the I/O transforms.  That's an important optimization
1875b24ab676SJeff Bonwick 	 * because otherwise we'd compress/encrypt all dmu_sync() data twice.
1876b24ab676SJeff Bonwick 	 */
1877b24ab676SJeff Bonwick 	for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) {
1878b24ab676SJeff Bonwick 		zio_t *lio = dde->dde_lead_zio[p];
1879b24ab676SJeff Bonwick 
1880b24ab676SJeff Bonwick 		if (lio != NULL) {
1881b24ab676SJeff Bonwick 			return (lio->io_orig_size != zio->io_orig_size ||
1882b24ab676SJeff Bonwick 			    bcmp(zio->io_orig_data, lio->io_orig_data,
1883b24ab676SJeff Bonwick 			    zio->io_orig_size) != 0);
1884b24ab676SJeff Bonwick 		}
1885b24ab676SJeff Bonwick 	}
1886b24ab676SJeff Bonwick 
1887b24ab676SJeff Bonwick 	for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) {
1888b24ab676SJeff Bonwick 		ddt_phys_t *ddp = &dde->dde_phys[p];
1889b24ab676SJeff Bonwick 
1890b24ab676SJeff Bonwick 		if (ddp->ddp_phys_birth != 0) {
1891b24ab676SJeff Bonwick 			arc_buf_t *abuf = NULL;
1892b24ab676SJeff Bonwick 			uint32_t aflags = ARC_WAIT;
1893b24ab676SJeff Bonwick 			blkptr_t blk = *zio->io_bp;
1894b24ab676SJeff Bonwick 			int error;
1895b24ab676SJeff Bonwick 
1896b24ab676SJeff Bonwick 			ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth);
1897b24ab676SJeff Bonwick 
1898b24ab676SJeff Bonwick 			ddt_exit(ddt);
1899b24ab676SJeff Bonwick 
1900b24ab676SJeff Bonwick 			error = arc_read_nolock(NULL, spa, &blk,
1901b24ab676SJeff Bonwick 			    arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ,
1902b24ab676SJeff Bonwick 			    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
1903b24ab676SJeff Bonwick 			    &aflags, &zio->io_bookmark);
1904b24ab676SJeff Bonwick 
1905b24ab676SJeff Bonwick 			if (error == 0) {
1906b24ab676SJeff Bonwick 				if (arc_buf_size(abuf) != zio->io_orig_size ||
1907b24ab676SJeff Bonwick 				    bcmp(abuf->b_data, zio->io_orig_data,
1908b24ab676SJeff Bonwick 				    zio->io_orig_size) != 0)
1909b24ab676SJeff Bonwick 					error = EEXIST;
1910b24ab676SJeff Bonwick 				VERIFY(arc_buf_remove_ref(abuf, &abuf) == 1);
1911b24ab676SJeff Bonwick 			}
1912b24ab676SJeff Bonwick 
1913b24ab676SJeff Bonwick 			ddt_enter(ddt);
1914b24ab676SJeff Bonwick 			return (error != 0);
1915b24ab676SJeff Bonwick 		}
1916b24ab676SJeff Bonwick 	}
1917b24ab676SJeff Bonwick 
1918b24ab676SJeff Bonwick 	return (B_FALSE);
1919b24ab676SJeff Bonwick }
1920b24ab676SJeff Bonwick 
1921b24ab676SJeff Bonwick static void
1922b24ab676SJeff Bonwick zio_ddt_child_write_ready(zio_t *zio)
1923b24ab676SJeff Bonwick {
1924b24ab676SJeff Bonwick 	int p = zio->io_prop.zp_copies;
1925b24ab676SJeff Bonwick 	ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp);
1926b24ab676SJeff Bonwick 	ddt_entry_t *dde = zio->io_private;
1927b24ab676SJeff Bonwick 	ddt_phys_t *ddp = &dde->dde_phys[p];
1928b24ab676SJeff Bonwick 	zio_t *pio;
1929b24ab676SJeff Bonwick 
1930b24ab676SJeff Bonwick 	if (zio->io_error)
1931b24ab676SJeff Bonwick 		return;
1932b24ab676SJeff Bonwick 
1933b24ab676SJeff Bonwick 	ddt_enter(ddt);
1934b24ab676SJeff Bonwick 
1935b24ab676SJeff Bonwick 	ASSERT(dde->dde_lead_zio[p] == zio);
1936b24ab676SJeff Bonwick 
1937b24ab676SJeff Bonwick 	ddt_phys_fill(ddp, zio->io_bp);
1938b24ab676SJeff Bonwick 
1939b24ab676SJeff Bonwick 	while ((pio = zio_walk_parents(zio)) != NULL)
1940b24ab676SJeff Bonwick 		ddt_bp_fill(ddp, pio->io_bp, zio->io_txg);
1941b24ab676SJeff Bonwick 
1942b24ab676SJeff Bonwick 	ddt_exit(ddt);
1943b24ab676SJeff Bonwick }
1944b24ab676SJeff Bonwick 
1945b24ab676SJeff Bonwick static void
1946b24ab676SJeff Bonwick zio_ddt_child_write_done(zio_t *zio)
1947b24ab676SJeff Bonwick {
1948b24ab676SJeff Bonwick 	int p = zio->io_prop.zp_copies;
1949b24ab676SJeff Bonwick 	ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp);
1950b24ab676SJeff Bonwick 	ddt_entry_t *dde = zio->io_private;
1951b24ab676SJeff Bonwick 	ddt_phys_t *ddp = &dde->dde_phys[p];
1952b24ab676SJeff Bonwick 
1953b24ab676SJeff Bonwick 	ddt_enter(ddt);
1954b24ab676SJeff Bonwick 
1955b24ab676SJeff Bonwick 	ASSERT(ddp->ddp_refcnt == 0);
1956b24ab676SJeff Bonwick 	ASSERT(dde->dde_lead_zio[p] == zio);
1957b24ab676SJeff Bonwick 	dde->dde_lead_zio[p] = NULL;
1958b24ab676SJeff Bonwick 
1959b24ab676SJeff Bonwick 	if (zio->io_error == 0) {
1960b24ab676SJeff Bonwick 		while (zio_walk_parents(zio) != NULL)
1961b24ab676SJeff Bonwick 			ddt_phys_addref(ddp);
1962b24ab676SJeff Bonwick 	} else {
1963b24ab676SJeff Bonwick 		ddt_phys_clear(ddp);
1964b24ab676SJeff Bonwick 	}
1965b24ab676SJeff Bonwick 
1966b24ab676SJeff Bonwick 	ddt_exit(ddt);
1967b24ab676SJeff Bonwick }
1968b24ab676SJeff Bonwick 
1969b24ab676SJeff Bonwick static void
1970b24ab676SJeff Bonwick zio_ddt_ditto_write_done(zio_t *zio)
1971b24ab676SJeff Bonwick {
1972b24ab676SJeff Bonwick 	int p = DDT_PHYS_DITTO;
1973b24ab676SJeff Bonwick 	zio_prop_t *zp = &zio->io_prop;
1974b24ab676SJeff Bonwick 	blkptr_t *bp = zio->io_bp;
1975b24ab676SJeff Bonwick 	ddt_t *ddt = ddt_select(zio->io_spa, bp);
1976b24ab676SJeff Bonwick 	ddt_entry_t *dde = zio->io_private;
1977b24ab676SJeff Bonwick 	ddt_phys_t *ddp = &dde->dde_phys[p];
1978b24ab676SJeff Bonwick 	ddt_key_t *ddk = &dde->dde_key;
1979b24ab676SJeff Bonwick 
1980b24ab676SJeff Bonwick 	ddt_enter(ddt);
1981b24ab676SJeff Bonwick 
1982b24ab676SJeff Bonwick 	ASSERT(ddp->ddp_refcnt == 0);
1983b24ab676SJeff Bonwick 	ASSERT(dde->dde_lead_zio[p] == zio);
1984b24ab676SJeff Bonwick 	dde->dde_lead_zio[p] = NULL;
1985b24ab676SJeff Bonwick 
1986b24ab676SJeff Bonwick 	if (zio->io_error == 0) {
1987b24ab676SJeff Bonwick 		ASSERT(ZIO_CHECKSUM_EQUAL(bp->blk_cksum, ddk->ddk_cksum));
1988b24ab676SJeff Bonwick 		ASSERT(zp->zp_copies < SPA_DVAS_PER_BP);
1989b24ab676SJeff Bonwick 		ASSERT(zp->zp_copies == BP_GET_NDVAS(bp) - BP_IS_GANG(bp));
1990b24ab676SJeff Bonwick 		if (ddp->ddp_phys_birth != 0)
1991b24ab676SJeff Bonwick 			ddt_phys_free(ddt, ddk, ddp, zio->io_txg);
1992b24ab676SJeff Bonwick 		ddt_phys_fill(ddp, bp);
1993b24ab676SJeff Bonwick 	}
1994b24ab676SJeff Bonwick 
1995b24ab676SJeff Bonwick 	ddt_exit(ddt);
1996b24ab676SJeff Bonwick }
1997b24ab676SJeff Bonwick 
1998b24ab676SJeff Bonwick static int
1999b24ab676SJeff Bonwick zio_ddt_write(zio_t *zio)
2000b24ab676SJeff Bonwick {
2001b24ab676SJeff Bonwick 	spa_t *spa = zio->io_spa;
2002b24ab676SJeff Bonwick 	blkptr_t *bp = zio->io_bp;
2003b24ab676SJeff Bonwick 	uint64_t txg = zio->io_txg;
2004b24ab676SJeff Bonwick 	zio_prop_t *zp = &zio->io_prop;
2005b24ab676SJeff Bonwick 	int p = zp->zp_copies;
2006b24ab676SJeff Bonwick 	int ditto_copies;
2007b24ab676SJeff Bonwick 	zio_t *cio = NULL;
2008b24ab676SJeff Bonwick 	zio_t *dio = NULL;
2009b24ab676SJeff Bonwick 	ddt_t *ddt = ddt_select(spa, bp);
2010b24ab676SJeff Bonwick 	ddt_entry_t *dde;
2011b24ab676SJeff Bonwick 	ddt_phys_t *ddp;
2012b24ab676SJeff Bonwick 
2013b24ab676SJeff Bonwick 	ASSERT(BP_GET_DEDUP(bp));
2014b24ab676SJeff Bonwick 	ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum);
2015b24ab676SJeff Bonwick 	ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override);
2016b24ab676SJeff Bonwick 
2017b24ab676SJeff Bonwick 	ddt_enter(ddt);
2018b24ab676SJeff Bonwick 	dde = ddt_lookup(ddt, bp, B_TRUE);
2019b24ab676SJeff Bonwick 	ddp = &dde->dde_phys[p];
2020b24ab676SJeff Bonwick 
2021b24ab676SJeff Bonwick 	if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) {
2022b24ab676SJeff Bonwick 		/*
2023b24ab676SJeff Bonwick 		 * If we're using a weak checksum, upgrade to a strong checksum
2024b24ab676SJeff Bonwick 		 * and try again.  If we're already using a strong checksum,
2025b24ab676SJeff Bonwick 		 * we can't resolve it, so just convert to an ordinary write.
2026b24ab676SJeff Bonwick 		 * (And automatically e-mail a paper to Nature?)
2027b24ab676SJeff Bonwick 		 */
2028b24ab676SJeff Bonwick 		if (!zio_checksum_table[zp->zp_checksum].ci_dedup) {
2029b24ab676SJeff Bonwick 			zp->zp_checksum = spa_dedup_checksum(spa);
2030b24ab676SJeff Bonwick 			zio_pop_transforms(zio);
2031b24ab676SJeff Bonwick 			zio->io_stage = ZIO_STAGE_OPEN;
2032b24ab676SJeff Bonwick 			BP_ZERO(bp);
2033b24ab676SJeff Bonwick 		} else {
2034b24ab676SJeff Bonwick 			zp->zp_dedup = 0;
2035b24ab676SJeff Bonwick 		}
2036b24ab676SJeff Bonwick 		zio->io_pipeline = ZIO_WRITE_PIPELINE;
2037b24ab676SJeff Bonwick 		ddt_exit(ddt);
2038b24ab676SJeff Bonwick 		return (ZIO_PIPELINE_CONTINUE);
2039b24ab676SJeff Bonwick 	}
2040b24ab676SJeff Bonwick 
2041b24ab676SJeff Bonwick 	ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp);
2042b24ab676SJeff Bonwick 	ASSERT(ditto_copies < SPA_DVAS_PER_BP);
2043b24ab676SJeff Bonwick 
2044b24ab676SJeff Bonwick 	if (ditto_copies > ddt_ditto_copies_present(dde) &&
2045b24ab676SJeff Bonwick 	    dde->dde_lead_zio[DDT_PHYS_DITTO] == NULL) {
2046b24ab676SJeff Bonwick 		zio_prop_t czp = *zp;
2047b24ab676SJeff Bonwick 
2048b24ab676SJeff Bonwick 		czp.zp_copies = ditto_copies;
2049b24ab676SJeff Bonwick 
2050b24ab676SJeff Bonwick 		/*
2051b24ab676SJeff Bonwick 		 * If we arrived here with an override bp, we won't have run
2052b24ab676SJeff Bonwick 		 * the transform stack, so we won't have the data we need to
2053b24ab676SJeff Bonwick 		 * generate a child i/o.  So, toss the override bp and restart.
2054b24ab676SJeff Bonwick 		 * This is safe, because using the override bp is just an
2055b24ab676SJeff Bonwick 		 * optimization; and it's rare, so the cost doesn't matter.
2056b24ab676SJeff Bonwick 		 */
2057b24ab676SJeff Bonwick 		if (zio->io_bp_override) {
2058b24ab676SJeff Bonwick 			zio_pop_transforms(zio);
2059b24ab676SJeff Bonwick 			zio->io_stage = ZIO_STAGE_OPEN;
2060b24ab676SJeff Bonwick 			zio->io_pipeline = ZIO_WRITE_PIPELINE;
2061b24ab676SJeff Bonwick 			zio->io_bp_override = NULL;
2062b24ab676SJeff Bonwick 			BP_ZERO(bp);
2063b24ab676SJeff Bonwick 			ddt_exit(ddt);
2064b24ab676SJeff Bonwick 			return (ZIO_PIPELINE_CONTINUE);
2065b24ab676SJeff Bonwick 		}
2066b24ab676SJeff Bonwick 
2067b24ab676SJeff Bonwick 		dio = zio_write(zio, spa, txg, bp, zio->io_orig_data,
2068b24ab676SJeff Bonwick 		    zio->io_orig_size, &czp, NULL,
2069b24ab676SJeff Bonwick 		    zio_ddt_ditto_write_done, dde, zio->io_priority,
2070b24ab676SJeff Bonwick 		    ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark);
2071b24ab676SJeff Bonwick 
2072b24ab676SJeff Bonwick 		zio_push_transform(dio, zio->io_data, zio->io_size, 0, NULL);
2073b24ab676SJeff Bonwick 		dde->dde_lead_zio[DDT_PHYS_DITTO] = dio;
2074b24ab676SJeff Bonwick 	}
2075b24ab676SJeff Bonwick 
2076b24ab676SJeff Bonwick 	if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) {
2077b24ab676SJeff Bonwick 		if (ddp->ddp_phys_birth != 0)
2078b24ab676SJeff Bonwick 			ddt_bp_fill(ddp, bp, txg);
2079b24ab676SJeff Bonwick 		if (dde->dde_lead_zio[p] != NULL)
2080b24ab676SJeff Bonwick 			zio_add_child(zio, dde->dde_lead_zio[p]);
2081b24ab676SJeff Bonwick 		else
2082b24ab676SJeff Bonwick 			ddt_phys_addref(ddp);
2083b24ab676SJeff Bonwick 	} else if (zio->io_bp_override) {
2084b24ab676SJeff Bonwick 		ASSERT(bp->blk_birth == txg);
2085b24ab676SJeff Bonwick 		ASSERT(BP_EQUAL(bp, zio->io_bp_override));
2086b24ab676SJeff Bonwick 		ddt_phys_fill(ddp, bp);
2087b24ab676SJeff Bonwick 		ddt_phys_addref(ddp);
2088b24ab676SJeff Bonwick 	} else {
2089b24ab676SJeff Bonwick 		cio = zio_write(zio, spa, txg, bp, zio->io_orig_data,
2090b24ab676SJeff Bonwick 		    zio->io_orig_size, zp, zio_ddt_child_write_ready,
2091b24ab676SJeff Bonwick 		    zio_ddt_child_write_done, dde, zio->io_priority,
2092b24ab676SJeff Bonwick 		    ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark);
2093b24ab676SJeff Bonwick 
2094b24ab676SJeff Bonwick 		zio_push_transform(cio, zio->io_data, zio->io_size, 0, NULL);
2095b24ab676SJeff Bonwick 		dde->dde_lead_zio[p] = cio;
2096b24ab676SJeff Bonwick 	}
2097b24ab676SJeff Bonwick 
2098b24ab676SJeff Bonwick 	ddt_exit(ddt);
2099b24ab676SJeff Bonwick 
2100b24ab676SJeff Bonwick 	if (cio)
2101b24ab676SJeff Bonwick 		zio_nowait(cio);
2102b24ab676SJeff Bonwick 	if (dio)
2103b24ab676SJeff Bonwick 		zio_nowait(dio);
2104b24ab676SJeff Bonwick 
2105b24ab676SJeff Bonwick 	return (ZIO_PIPELINE_CONTINUE);
2106b24ab676SJeff Bonwick }
2107b24ab676SJeff Bonwick 
21083f9d6ad7SLin Ling ddt_entry_t *freedde; /* for debugging */
21093f9d6ad7SLin Ling 
2110b24ab676SJeff Bonwick static int
2111b24ab676SJeff Bonwick zio_ddt_free(zio_t *zio)
2112b24ab676SJeff Bonwick {
2113b24ab676SJeff Bonwick 	spa_t *spa = zio->io_spa;
2114b24ab676SJeff Bonwick 	blkptr_t *bp = zio->io_bp;
2115b24ab676SJeff Bonwick 	ddt_t *ddt = ddt_select(spa, bp);
2116b24ab676SJeff Bonwick 	ddt_entry_t *dde;
2117b24ab676SJeff Bonwick 	ddt_phys_t *ddp;
2118b24ab676SJeff Bonwick 
2119b24ab676SJeff Bonwick 	ASSERT(BP_GET_DEDUP(bp));
2120b24ab676SJeff Bonwick 	ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
2121b24ab676SJeff Bonwick 
2122b24ab676SJeff Bonwick 	ddt_enter(ddt);
21233f9d6ad7SLin Ling 	freedde = dde = ddt_lookup(ddt, bp, B_TRUE);
2124b24ab676SJeff Bonwick 	ddp = ddt_phys_select(dde, bp);
2125b24ab676SJeff Bonwick 	ddt_phys_decref(ddp);
2126b24ab676SJeff Bonwick 	ddt_exit(ddt);
2127b24ab676SJeff Bonwick 
2128b24ab676SJeff Bonwick 	return (ZIO_PIPELINE_CONTINUE);
2129b24ab676SJeff Bonwick }
2130b24ab676SJeff Bonwick 
2131b24ab676SJeff Bonwick /*
2132b24ab676SJeff Bonwick  * ==========================================================================
2133b24ab676SJeff Bonwick  * Allocate and free blocks
2134b24ab676SJeff Bonwick  * ==========================================================================
2135b24ab676SJeff Bonwick  */
2136e05725b1Sbonwick static int
2137fa9e4066Sahrens zio_dva_allocate(zio_t *zio)
2138fa9e4066Sahrens {
21398654d025Sperrin 	spa_t *spa = zio->io_spa;
2140b24ab676SJeff Bonwick 	metaslab_class_t *mc = spa_normal_class(spa);
2141fa9e4066Sahrens 	blkptr_t *bp = zio->io_bp;
2142fa9e4066Sahrens 	int error;
214309c9d376SGeorge Wilson 	int flags = 0;
2144fa9e4066Sahrens 
2145f5383399SBill Moore 	if (zio->io_gang_leader == NULL) {
2146f5383399SBill Moore 		ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
2147f5383399SBill Moore 		zio->io_gang_leader = zio;
2148f5383399SBill Moore 	}
2149f5383399SBill Moore 
2150fa9e4066Sahrens 	ASSERT(BP_IS_HOLE(bp));
2151b420f3adSRichard Lowe 	ASSERT3U(BP_GET_NDVAS(bp), ==, 0);
2152b24ab676SJeff Bonwick 	ASSERT3U(zio->io_prop.zp_copies, >, 0);
2153b24ab676SJeff Bonwick 	ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa));
2154fa9e4066Sahrens 	ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp));
2155fa9e4066Sahrens 
215609c9d376SGeorge Wilson 	/*
215709c9d376SGeorge Wilson 	 * The dump device does not support gang blocks so allocation on
215809c9d376SGeorge Wilson 	 * behalf of the dump device (i.e. ZIO_FLAG_NODATA) must avoid
215909c9d376SGeorge Wilson 	 * the "fast" gang feature.
216009c9d376SGeorge Wilson 	 */
216109c9d376SGeorge Wilson 	flags |= (zio->io_flags & ZIO_FLAG_NODATA) ? METASLAB_GANG_AVOID : 0;
216209c9d376SGeorge Wilson 	flags |= (zio->io_flags & ZIO_FLAG_GANG_CHILD) ?
216309c9d376SGeorge Wilson 	    METASLAB_GANG_CHILD : 0;
2164e14bb325SJeff Bonwick 	error = metaslab_alloc(spa, mc, zio->io_size, bp,
216509c9d376SGeorge Wilson 	    zio->io_prop.zp_copies, zio->io_txg, NULL, flags);
2166fa9e4066Sahrens 
2167e14bb325SJeff Bonwick 	if (error) {
216809c9d376SGeorge Wilson 		spa_dbgmsg(spa, "%s: metaslab allocation failure: zio %p, "
216909c9d376SGeorge Wilson 		    "size %llu, error %d", spa_name(spa), zio, zio->io_size,
217009c9d376SGeorge Wilson 		    error);
2171e14bb325SJeff Bonwick 		if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE)
2172e14bb325SJeff Bonwick 			return (zio_write_gang_block(zio));
2173fa9e4066Sahrens 		zio->io_error = error;
2174fa9e4066Sahrens 	}
2175e05725b1Sbonwick 
2176e05725b1Sbonwick 	return (ZIO_PIPELINE_CONTINUE);
2177fa9e4066Sahrens }
2178fa9e4066Sahrens 
2179e05725b1Sbonwick static int
2180fa9e4066Sahrens zio_dva_free(zio_t *zio)
2181fa9e4066Sahrens {
2182e14bb325SJeff Bonwick 	metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE);
2183fa9e4066Sahrens 
2184e05725b1Sbonwick 	return (ZIO_PIPELINE_CONTINUE);
2185fa9e4066Sahrens }
2186fa9e4066Sahrens 
2187e05725b1Sbonwick static int
2188fa9e4066Sahrens zio_dva_claim(zio_t *zio)
2189fa9e4066Sahrens {
2190e14bb325SJeff Bonwick 	int error;
2191e14bb325SJeff Bonwick 
2192e14bb325SJeff Bonwick 	error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg);
2193e14bb325SJeff Bonwick 	if (error)
2194e14bb325SJeff Bonwick 		zio->io_error = error;
2195fa9e4066Sahrens 
2196e05725b1Sbonwick 	return (ZIO_PIPELINE_CONTINUE);
2197fa9e4066Sahrens }
2198fa9e4066Sahrens 
2199e14bb325SJeff Bonwick /*
2200e14bb325SJeff Bonwick  * Undo an allocation.  This is used by zio_done() when an I/O fails
2201e14bb325SJeff Bonwick  * and we want to give back the block we just allocated.
2202e14bb325SJeff Bonwick  * This handles both normal blocks and gang blocks.
2203e14bb325SJeff Bonwick  */
2204e14bb325SJeff Bonwick static void
2205e14bb325SJeff Bonwick zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp)
2206e14bb325SJeff Bonwick {
2207e14bb325SJeff Bonwick 	ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp));
2208b24ab676SJeff Bonwick 	ASSERT(zio->io_bp_override == NULL);
2209e14bb325SJeff Bonwick 
2210e14bb325SJeff Bonwick 	if (!BP_IS_HOLE(bp))
2211b24ab676SJeff Bonwick 		metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE);
2212e14bb325SJeff Bonwick 
2213e14bb325SJeff Bonwick 	if (gn != NULL) {
2214e14bb325SJeff Bonwick 		for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
2215e14bb325SJeff Bonwick 			zio_dva_unallocate(zio, gn->gn_child[g],
2216e14bb325SJeff Bonwick 			    &gn->gn_gbh->zg_blkptr[g]);
2217e14bb325SJeff Bonwick 		}
2218e14bb325SJeff Bonwick 	}
2219e14bb325SJeff Bonwick }
2220e14bb325SJeff Bonwick 
2221e14bb325SJeff Bonwick /*
2222e14bb325SJeff Bonwick  * Try to allocate an intent log block.  Return 0 on success, errno on failure.
2223e14bb325SJeff Bonwick  */
2224e14bb325SJeff Bonwick int
2225b24ab676SJeff Bonwick zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp, blkptr_t *old_bp,
2226b24ab676SJeff Bonwick     uint64_t size, boolean_t use_slog)
2227e14bb325SJeff Bonwick {
2228e09fa4daSNeil Perrin 	int error = 1;
2229e14bb325SJeff Bonwick 
2230b24ab676SJeff Bonwick 	ASSERT(txg > spa_syncing_txg(spa));
2231b24ab676SJeff Bonwick 
2232840345f6SGeorge Wilson 	/*
2233840345f6SGeorge Wilson 	 * ZIL blocks are always contiguous (i.e. not gang blocks) so we
2234840345f6SGeorge Wilson 	 * set the METASLAB_GANG_AVOID flag so that they don't "fast gang"
2235840345f6SGeorge Wilson 	 * when allocating them.
2236840345f6SGeorge Wilson 	 */
2237840345f6SGeorge Wilson 	if (use_slog) {
2238b24ab676SJeff Bonwick 		error = metaslab_alloc(spa, spa_log_class(spa), size,
2239840345f6SGeorge Wilson 		    new_bp, 1, txg, old_bp,
2240840345f6SGeorge Wilson 		    METASLAB_HINTBP_AVOID | METASLAB_GANG_AVOID);
2241840345f6SGeorge Wilson 	}
2242e14bb325SJeff Bonwick 
2243840345f6SGeorge Wilson 	if (error) {
2244b24ab676SJeff Bonwick 		error = metaslab_alloc(spa, spa_normal_class(spa), size,
2245840345f6SGeorge Wilson 		    new_bp, 1, txg, old_bp,
2246840345f6SGeorge Wilson 		    METASLAB_HINTBP_AVOID | METASLAB_GANG_AVOID);
2247840345f6SGeorge Wilson 	}
2248e14bb325SJeff Bonwick 
2249e14bb325SJeff Bonwick 	if (error == 0) {
2250e14bb325SJeff Bonwick 		BP_SET_LSIZE(new_bp, size);
2251e14bb325SJeff Bonwick 		BP_SET_PSIZE(new_bp, size);
2252e14bb325SJeff Bonwick 		BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF);
22536e1f5caaSNeil Perrin 		BP_SET_CHECKSUM(new_bp,
22546e1f5caaSNeil Perrin 		    spa_version(spa) >= SPA_VERSION_SLIM_ZIL
22556e1f5caaSNeil Perrin 		    ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG);
2256e14bb325SJeff Bonwick 		BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG);
2257e14bb325SJeff Bonwick 		BP_SET_LEVEL(new_bp, 0);
2258b24ab676SJeff Bonwick 		BP_SET_DEDUP(new_bp, 0);
2259e14bb325SJeff Bonwick 		BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER);
2260e14bb325SJeff Bonwick 	}
2261e14bb325SJeff Bonwick 
2262e14bb325SJeff Bonwick 	return (error);
2263e14bb325SJeff Bonwick }
2264e14bb325SJeff Bonwick 
2265e14bb325SJeff Bonwick /*
2266b24ab676SJeff Bonwick  * Free an intent log block.
2267e14bb325SJeff Bonwick  */
2268e14bb325SJeff Bonwick void
2269b24ab676SJeff Bonwick zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp)
2270e14bb325SJeff Bonwick {
2271b24ab676SJeff Bonwick 	ASSERT(BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG);
2272e14bb325SJeff Bonwick 	ASSERT(!BP_IS_GANG(bp));
2273e14bb325SJeff Bonwick 
2274b24ab676SJeff Bonwick 	zio_free(spa, txg, bp);
2275e14bb325SJeff Bonwick }
2276e14bb325SJeff Bonwick 
2277fa9e4066Sahrens /*
2278fa9e4066Sahrens  * ==========================================================================
2279fa9e4066Sahrens  * Read and write to physical devices
2280fa9e4066Sahrens  * ==========================================================================
2281fa9e4066Sahrens  */
2282e05725b1Sbonwick static int
228344cd46caSbillm zio_vdev_io_start(zio_t *zio)
2284fa9e4066Sahrens {
2285fa9e4066Sahrens 	vdev_t *vd = zio->io_vd;
228644cd46caSbillm 	uint64_t align;
22870a4e9518Sgw 	spa_t *spa = zio->io_spa;
22880a4e9518Sgw 
2289e14bb325SJeff Bonwick 	ASSERT(zio->io_error == 0);
2290e14bb325SJeff Bonwick 	ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0);
2291fa9e4066Sahrens 
2292e14bb325SJeff Bonwick 	if (vd == NULL) {
2293e14bb325SJeff Bonwick 		if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER))
2294e14bb325SJeff Bonwick 			spa_config_enter(spa, SCL_ZIO, zio, RW_READER);
2295fa9e4066Sahrens 
2296e14bb325SJeff Bonwick 		/*
2297e14bb325SJeff Bonwick 		 * The mirror_ops handle multiple DVAs in a single BP.
2298e14bb325SJeff Bonwick 		 */
2299e14bb325SJeff Bonwick 		return (vdev_mirror_ops.vdev_op_io_start(zio));
2300fa9e4066Sahrens 	}
2301fa9e4066Sahrens 
230244ecc532SGeorge Wilson 	/*
230344ecc532SGeorge Wilson 	 * We keep track of time-sensitive I/Os so that the scan thread
230444ecc532SGeorge Wilson 	 * can quickly react to certain workloads.  In particular, we care
230544ecc532SGeorge Wilson 	 * about non-scrubbing, top-level reads and writes with the following
230644ecc532SGeorge Wilson 	 * characteristics:
230744ecc532SGeorge Wilson 	 * 	- synchronous writes of user data to non-slog devices
230844ecc532SGeorge Wilson 	 *	- any reads of user data
230944ecc532SGeorge Wilson 	 * When these conditions are met, adjust the timestamp of spa_last_io
231044ecc532SGeorge Wilson 	 * which allows the scan thread to adjust its workload accordingly.
231144ecc532SGeorge Wilson 	 */
231244ecc532SGeorge Wilson 	if (!(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && zio->io_bp != NULL &&
231344ecc532SGeorge Wilson 	    vd == vd->vdev_top && !vd->vdev_islog &&
231444ecc532SGeorge Wilson 	    zio->io_bookmark.zb_objset != DMU_META_OBJSET &&
231544ecc532SGeorge Wilson 	    zio->io_txg != spa_syncing_txg(spa)) {
231644ecc532SGeorge Wilson 		uint64_t old = spa->spa_last_io;
231744ecc532SGeorge Wilson 		uint64_t new = ddi_get_lbolt64();
231844ecc532SGeorge Wilson 		if (old != new)
231944ecc532SGeorge Wilson 			(void) atomic_cas_64(&spa->spa_last_io, old, new);
232044ecc532SGeorge Wilson 	}
232144ecc532SGeorge Wilson 
2322e14bb325SJeff Bonwick 	align = 1ULL << vd->vdev_top->vdev_ashift;
2323e14bb325SJeff Bonwick 
2324ecc2d604Sbonwick 	if (P2PHASE(zio->io_size, align) != 0) {
2325ecc2d604Sbonwick 		uint64_t asize = P2ROUNDUP(zio->io_size, align);
2326ecc2d604Sbonwick 		char *abuf = zio_buf_alloc(asize);
2327e14bb325SJeff Bonwick 		ASSERT(vd == vd->vdev_top);
2328ecc2d604Sbonwick 		if (zio->io_type == ZIO_TYPE_WRITE) {
2329ecc2d604Sbonwick 			bcopy(zio->io_data, abuf, zio->io_size);
2330ecc2d604Sbonwick 			bzero(abuf + zio->io_size, asize - zio->io_size);
2331ecc2d604Sbonwick 		}
2332e14bb325SJeff Bonwick 		zio_push_transform(zio, abuf, asize, asize, zio_subblock);
2333ecc2d604Sbonwick 	}
2334ecc2d604Sbonwick 
2335ecc2d604Sbonwick 	ASSERT(P2PHASE(zio->io_offset, align) == 0);
2336ecc2d604Sbonwick 	ASSERT(P2PHASE(zio->io_size, align) == 0);
2337f9af39baSGeorge Wilson 	VERIFY(zio->io_type != ZIO_TYPE_WRITE || spa_writeable(spa));
23388ad4d6ddSJeff Bonwick 
23398ad4d6ddSJeff Bonwick 	/*
23408ad4d6ddSJeff Bonwick 	 * If this is a repair I/O, and there's no self-healing involved --
23418ad4d6ddSJeff Bonwick 	 * that is, we're just resilvering what we expect to resilver --
23428ad4d6ddSJeff Bonwick 	 * then don't do the I/O unless zio's txg is actually in vd's DTL.
23438ad4d6ddSJeff Bonwick 	 * This prevents spurious resilvering with nested replication.
23448ad4d6ddSJeff Bonwick 	 * For example, given a mirror of mirrors, (A+B)+(C+D), if only
23458ad4d6ddSJeff Bonwick 	 * A is out of date, we'll read from C+D, then use the data to
23468ad4d6ddSJeff Bonwick 	 * resilver A+B -- but we don't actually want to resilver B, just A.
23478ad4d6ddSJeff Bonwick 	 * The top-level mirror has no way to know this, so instead we just
23488ad4d6ddSJeff Bonwick 	 * discard unnecessary repairs as we work our way down the vdev tree.
23498ad4d6ddSJeff Bonwick 	 * The same logic applies to any form of nested replication:
23508ad4d6ddSJeff Bonwick 	 * ditto + mirror, RAID-Z + replacing, etc.  This covers them all.
23518ad4d6ddSJeff Bonwick 	 */
23528ad4d6ddSJeff Bonwick 	if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) &&
23538ad4d6ddSJeff Bonwick 	    !(zio->io_flags & ZIO_FLAG_SELF_HEAL) &&
23548ad4d6ddSJeff Bonwick 	    zio->io_txg != 0 &&	/* not a delegated i/o */
23558ad4d6ddSJeff Bonwick 	    !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) {
23568ad4d6ddSJeff Bonwick 		ASSERT(zio->io_type == ZIO_TYPE_WRITE);
23578ad4d6ddSJeff Bonwick 		zio_vdev_io_bypass(zio);
23588ad4d6ddSJeff Bonwick 		return (ZIO_PIPELINE_CONTINUE);
23598ad4d6ddSJeff Bonwick 	}
2360fa9e4066Sahrens 
2361e14bb325SJeff Bonwick 	if (vd->vdev_ops->vdev_op_leaf &&
2362e14bb325SJeff Bonwick 	    (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE)) {
2363e14bb325SJeff Bonwick 
2364e14bb325SJeff Bonwick 		if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio) == 0)
2365a3f829aeSBill Moore 			return (ZIO_PIPELINE_CONTINUE);
2366e14bb325SJeff Bonwick 
2367e14bb325SJeff Bonwick 		if ((zio = vdev_queue_io(zio)) == NULL)
2368e14bb325SJeff Bonwick 			return (ZIO_PIPELINE_STOP);
2369e14bb325SJeff Bonwick 
2370e14bb325SJeff Bonwick 		if (!vdev_accessible(vd, zio)) {
2371e14bb325SJeff Bonwick 			zio->io_error = ENXIO;
2372e14bb325SJeff Bonwick 			zio_interrupt(zio);
2373e14bb325SJeff Bonwick 			return (ZIO_PIPELINE_STOP);
2374e14bb325SJeff Bonwick 		}
2375e14bb325SJeff Bonwick 	}
2376e14bb325SJeff Bonwick 
2377e05725b1Sbonwick 	return (vd->vdev_ops->vdev_op_io_start(zio));
2378fa9e4066Sahrens }
2379fa9e4066Sahrens 
2380e05725b1Sbonwick static int
2381fa9e4066Sahrens zio_vdev_io_done(zio_t *zio)
2382fa9e4066Sahrens {
2383e14bb325SJeff Bonwick 	vdev_t *vd = zio->io_vd;
2384e14bb325SJeff Bonwick 	vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops;
2385e14bb325SJeff Bonwick 	boolean_t unexpected_error = B_FALSE;
2386e05725b1Sbonwick 
2387e14bb325SJeff Bonwick 	if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE))
2388e14bb325SJeff Bonwick 		return (ZIO_PIPELINE_STOP);
2389fa9e4066Sahrens 
2390e14bb325SJeff Bonwick 	ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE);
2391e14bb325SJeff Bonwick 
2392e14bb325SJeff Bonwick 	if (vd != NULL && vd->vdev_ops->vdev_op_leaf) {
2393e14bb325SJeff Bonwick 
2394e14bb325SJeff Bonwick 		vdev_queue_io_done(zio);
2395fa9e4066Sahrens 
2396e14bb325SJeff Bonwick 		if (zio->io_type == ZIO_TYPE_WRITE)
2397e14bb325SJeff Bonwick 			vdev_cache_write(zio);
2398e14bb325SJeff Bonwick 
2399e14bb325SJeff Bonwick 		if (zio_injection_enabled && zio->io_error == 0)
24008956713aSEric Schrock 			zio->io_error = zio_handle_device_injection(vd,
24018956713aSEric Schrock 			    zio, EIO);
2402e14bb325SJeff Bonwick 
2403e14bb325SJeff Bonwick 		if (zio_injection_enabled && zio->io_error == 0)
2404e14bb325SJeff Bonwick 			zio->io_error = zio_handle_label_injection(zio, EIO);
2405e14bb325SJeff Bonwick 
2406e14bb325SJeff Bonwick 		if (zio->io_error) {
2407e14bb325SJeff Bonwick 			if (!vdev_accessible(vd, zio)) {
2408e14bb325SJeff Bonwick 				zio->io_error = ENXIO;
2409e14bb325SJeff Bonwick 			} else {
2410e14bb325SJeff Bonwick 				unexpected_error = B_TRUE;
2411e14bb325SJeff Bonwick 			}
2412e14bb325SJeff Bonwick 		}
241351ece835Seschrock 	}
2414fa9e4066Sahrens 
2415e14bb325SJeff Bonwick 	ops->vdev_op_io_done(zio);
2416e14bb325SJeff Bonwick 
2417e14bb325SJeff Bonwick 	if (unexpected_error)
2418a3f829aeSBill Moore 		VERIFY(vdev_probe(vd, zio) == NULL);
2419e14bb325SJeff Bonwick 
2420e14bb325SJeff Bonwick 	return (ZIO_PIPELINE_CONTINUE);
2421fa9e4066Sahrens }
2422fa9e4066Sahrens 
242322fe2c88SJonathan Adams /*
242422fe2c88SJonathan Adams  * For non-raidz ZIOs, we can just copy aside the bad data read from the
242522fe2c88SJonathan Adams  * disk, and use that to finish the checksum ereport later.
242622fe2c88SJonathan Adams  */
242722fe2c88SJonathan Adams static void
242822fe2c88SJonathan Adams zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr,
242922fe2c88SJonathan Adams     const void *good_buf)
243022fe2c88SJonathan Adams {
243122fe2c88SJonathan Adams 	/* no processing needed */
243222fe2c88SJonathan Adams 	zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE);
243322fe2c88SJonathan Adams }
243422fe2c88SJonathan Adams 
243522fe2c88SJonathan Adams /*ARGSUSED*/
243622fe2c88SJonathan Adams void
243722fe2c88SJonathan Adams zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored)
243822fe2c88SJonathan Adams {
243922fe2c88SJonathan Adams 	void *buf = zio_buf_alloc(zio->io_size);
244022fe2c88SJonathan Adams 
244122fe2c88SJonathan Adams 	bcopy(zio->io_data, buf, zio->io_size);
244222fe2c88SJonathan Adams 
244322fe2c88SJonathan Adams 	zcr->zcr_cbinfo = zio->io_size;
244422fe2c88SJonathan Adams 	zcr->zcr_cbdata = buf;
244522fe2c88SJonathan Adams 	zcr->zcr_finish = zio_vsd_default_cksum_finish;
244622fe2c88SJonathan Adams 	zcr->zcr_free = zio_buf_free;
244722fe2c88SJonathan Adams }
244822fe2c88SJonathan Adams 
2449e05725b1Sbonwick static int
2450fa9e4066Sahrens zio_vdev_io_assess(zio_t *zio)
2451fa9e4066Sahrens {
2452fa9e4066Sahrens 	vdev_t *vd = zio->io_vd;
2453e14bb325SJeff Bonwick 
2454e14bb325SJeff Bonwick 	if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE))
2455e14bb325SJeff Bonwick 		return (ZIO_PIPELINE_STOP);
2456e14bb325SJeff Bonwick 
2457e14bb325SJeff Bonwick 	if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER))
2458e14bb325SJeff Bonwick 		spa_config_exit(zio->io_spa, SCL_ZIO, zio);
2459e14bb325SJeff Bonwick 
2460e14bb325SJeff Bonwick 	if (zio->io_vsd != NULL) {
246122fe2c88SJonathan Adams 		zio->io_vsd_ops->vsd_free(zio);
2462e14bb325SJeff Bonwick 		zio->io_vsd = NULL;
2463ecc2d604Sbonwick 	}
2464ecc2d604Sbonwick 
2465e14bb325SJeff Bonwick 	if (zio_injection_enabled && zio->io_error == 0)
2466ea8dc4b6Seschrock 		zio->io_error = zio_handle_fault_injection(zio, EIO);
2467ea8dc4b6Seschrock 
2468fa9e4066Sahrens 	/*
2469fa9e4066Sahrens 	 * If the I/O failed, determine whether we should attempt to retry it.
247035a5a358SJonathan Adams 	 *
247135a5a358SJonathan Adams 	 * On retry, we cut in line in the issue queue, since we don't want
247235a5a358SJonathan Adams 	 * compression/checksumming/etc. work to prevent our (cheap) IO reissue.
2473fa9e4066Sahrens 	 */
2474e14bb325SJeff Bonwick 	if (zio->io_error && vd == NULL &&
2475e14bb325SJeff Bonwick 	    !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) {
2476e14bb325SJeff Bonwick 		ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE));	/* not a leaf */
2477e14bb325SJeff Bonwick 		ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS));	/* not a leaf */
2478fa9e4066Sahrens 		zio->io_error = 0;
2479e14bb325SJeff Bonwick 		zio->io_flags |= ZIO_FLAG_IO_RETRY |
2480e14bb325SJeff Bonwick 		    ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE;
2481b24ab676SJeff Bonwick 		zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1;
248235a5a358SJonathan Adams 		zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE,
248335a5a358SJonathan Adams 		    zio_requeue_io_start_cut_in_line);
2484e14bb325SJeff Bonwick 		return (ZIO_PIPELINE_STOP);
2485ea8dc4b6Seschrock 	}
2486fa9e4066Sahrens 
2487e14bb325SJeff Bonwick 	/*
2488e14bb325SJeff Bonwick 	 * If we got an error on a leaf device, convert it to ENXIO
2489e14bb325SJeff Bonwick 	 * if the device is not accessible at all.
2490e14bb325SJeff Bonwick 	 */
2491e14bb325SJeff Bonwick 	if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf &&
2492e14bb325SJeff Bonwick 	    !vdev_accessible(vd, zio))
2493e14bb325SJeff Bonwick 		zio->io_error = ENXIO;
2494e14bb325SJeff Bonwick 
2495e14bb325SJeff Bonwick 	/*
2496e14bb325SJeff Bonwick 	 * If we can't write to an interior vdev (mirror or RAID-Z),
2497e14bb325SJeff Bonwick 	 * set vdev_cant_write so that we stop trying to allocate from it.
2498e14bb325SJeff Bonwick 	 */
2499e14bb325SJeff Bonwick 	if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE &&
2500e14bb325SJeff Bonwick 	    vd != NULL && !vd->vdev_ops->vdev_op_leaf)
2501e14bb325SJeff Bonwick 		vd->vdev_cant_write = B_TRUE;
2502e14bb325SJeff Bonwick 
2503e14bb325SJeff Bonwick 	if (zio->io_error)
2504e14bb325SJeff Bonwick 		zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
2505e14bb325SJeff Bonwick 
2506e05725b1Sbonwick 	return (ZIO_PIPELINE_CONTINUE);
2507fa9e4066Sahrens }
2508fa9e4066Sahrens 
2509fa9e4066Sahrens void
2510fa9e4066Sahrens zio_vdev_io_reissue(zio_t *zio)
2511fa9e4066Sahrens {
2512fa9e4066Sahrens 	ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START);
2513fa9e4066Sahrens 	ASSERT(zio->io_error == 0);
2514fa9e4066Sahrens 
2515b24ab676SJeff Bonwick 	zio->io_stage >>= 1;
2516fa9e4066Sahrens }
2517fa9e4066Sahrens 
2518fa9e4066Sahrens void
2519fa9e4066Sahrens zio_vdev_io_redone(zio_t *zio)
2520fa9e4066Sahrens {
2521fa9e4066Sahrens 	ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE);
2522fa9e4066Sahrens 
2523b24ab676SJeff Bonwick 	zio->io_stage >>= 1;
2524fa9e4066Sahrens }
2525fa9e4066Sahrens 
2526fa9e4066Sahrens void
2527fa9e4066Sahrens zio_vdev_io_bypass(zio_t *zio)
2528fa9e4066Sahrens {
2529fa9e4066Sahrens 	ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START);
2530fa9e4066Sahrens 	ASSERT(zio->io_error == 0);
2531fa9e4066Sahrens 
2532fa9e4066Sahrens 	zio->io_flags |= ZIO_FLAG_IO_BYPASS;
2533b24ab676SJeff Bonwick 	zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1;
2534fa9e4066Sahrens }
2535fa9e4066Sahrens 
2536fa9e4066Sahrens /*
2537fa9e4066Sahrens  * ==========================================================================
2538fa9e4066Sahrens  * Generate and verify checksums
2539fa9e4066Sahrens  * ==========================================================================
2540fa9e4066Sahrens  */
2541e05725b1Sbonwick static int
2542fa9e4066Sahrens zio_checksum_generate(zio_t *zio)
2543fa9e4066Sahrens {
2544fa9e4066Sahrens 	blkptr_t *bp = zio->io_bp;
2545e14bb325SJeff Bonwick 	enum zio_checksum checksum;
2546fa9e4066Sahrens 
2547e14bb325SJeff Bonwick 	if (bp == NULL) {
2548e14bb325SJeff Bonwick 		/*
2549e14bb325SJeff Bonwick 		 * This is zio_write_phys().
2550e14bb325SJeff Bonwick 		 * We're either generating a label checksum, or none at all.
2551e14bb325SJeff Bonwick 		 */
2552e14bb325SJeff Bonwick 		checksum = zio->io_prop.zp_checksum;
2553e14bb325SJeff Bonwick 
2554e14bb325SJeff Bonwick 		if (checksum == ZIO_CHECKSUM_OFF)
2555e14bb325SJeff Bonwick 			return (ZIO_PIPELINE_CONTINUE);
2556fa9e4066Sahrens 
2557e14bb325SJeff Bonwick 		ASSERT(checksum == ZIO_CHECKSUM_LABEL);
2558e14bb325SJeff Bonwick 	} else {
2559e14bb325SJeff Bonwick 		if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) {
2560e14bb325SJeff Bonwick 			ASSERT(!IO_IS_ALLOCATING(zio));
2561e14bb325SJeff Bonwick 			checksum = ZIO_CHECKSUM_GANG_HEADER;
2562e14bb325SJeff Bonwick 		} else {
2563e14bb325SJeff Bonwick 			checksum = BP_GET_CHECKSUM(bp);
2564e14bb325SJeff Bonwick 		}
2565e14bb325SJeff Bonwick 	}
2566fa9e4066Sahrens 
2567e14bb325SJeff Bonwick 	zio_checksum_compute(zio, checksum, zio->io_data, zio->io_size);
2568fa9e4066Sahrens 
2569e05725b1Sbonwick 	return (ZIO_PIPELINE_CONTINUE);
2570fa9e4066Sahrens }
2571fa9e4066Sahrens 
2572e05725b1Sbonwick static int
2573e14bb325SJeff Bonwick zio_checksum_verify(zio_t *zio)
2574fa9e4066Sahrens {
257522fe2c88SJonathan Adams 	zio_bad_cksum_t info;
2576e14bb325SJeff Bonwick 	blkptr_t *bp = zio->io_bp;
2577e14bb325SJeff Bonwick 	int error;
2578fa9e4066Sahrens 
2579b24ab676SJeff Bonwick 	ASSERT(zio->io_vd != NULL);
2580b24ab676SJeff Bonwick 
2581e14bb325SJeff Bonwick 	if (bp == NULL) {
2582e14bb325SJeff Bonwick 		/*
2583e14bb325SJeff Bonwick 		 * This is zio_read_phys().
2584e14bb325SJeff Bonwick 		 * We're either verifying a label checksum, or nothing at all.
2585e14bb325SJeff Bonwick 		 */
2586e14bb325SJeff Bonwick 		if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF)
2587e14bb325SJeff Bonwick 			return (ZIO_PIPELINE_CONTINUE);
2588fa9e4066Sahrens 
2589e14bb325SJeff Bonwick 		ASSERT(zio->io_prop.zp_checksum == ZIO_CHECKSUM_LABEL);
2590e14bb325SJeff Bonwick 	}
2591fa9e4066Sahrens 
259222fe2c88SJonathan Adams 	if ((error = zio_checksum_error(zio, &info)) != 0) {
2593e14bb325SJeff Bonwick 		zio->io_error = error;
2594e14bb325SJeff Bonwick 		if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) {
259522fe2c88SJonathan Adams 			zfs_ereport_start_checksum(zio->io_spa,
259622fe2c88SJonathan Adams 			    zio->io_vd, zio, zio->io_offset,
259722fe2c88SJonathan Adams 			    zio->io_size, NULL, &info);
2598e14bb325SJeff Bonwick 		}
2599fa9e4066Sahrens 	}
2600fa9e4066Sahrens 
2601e05725b1Sbonwick 	return (ZIO_PIPELINE_CONTINUE);
2602fa9e4066Sahrens }
2603fa9e4066Sahrens 
2604fa9e4066Sahrens /*
2605fa9e4066Sahrens  * Called by RAID-Z to ensure we don't compute the checksum twice.
2606fa9e4066Sahrens  */
2607fa9e4066Sahrens void
2608fa9e4066Sahrens zio_checksum_verified(zio_t *zio)
2609fa9e4066Sahrens {
2610b24ab676SJeff Bonwick 	zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY;
2611fa9e4066Sahrens }
2612fa9e4066Sahrens 
2613fa9e4066Sahrens /*
2614e14bb325SJeff Bonwick  * ==========================================================================
2615e14bb325SJeff Bonwick  * Error rank.  Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other.
2616e14bb325SJeff Bonwick  * An error of 0 indictes success.  ENXIO indicates whole-device failure,
2617e14bb325SJeff Bonwick  * which may be transient (e.g. unplugged) or permament.  ECKSUM and EIO
2618e14bb325SJeff Bonwick  * indicate errors that are specific to one I/O, and most likely permanent.
2619e14bb325SJeff Bonwick  * Any other error is presumed to be worse because we weren't expecting it.
2620e14bb325SJeff Bonwick  * ==========================================================================
2621fa9e4066Sahrens  */
2622e14bb325SJeff Bonwick int
2623e14bb325SJeff Bonwick zio_worst_error(int e1, int e2)
2624fa9e4066Sahrens {
2625e14bb325SJeff Bonwick 	static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO };
2626e14bb325SJeff Bonwick 	int r1, r2;
2627e14bb325SJeff Bonwick 
2628e14bb325SJeff Bonwick 	for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++)
2629e14bb325SJeff Bonwick 		if (e1 == zio_error_rank[r1])
2630e14bb325SJeff Bonwick 			break;
2631e14bb325SJeff Bonwick 
2632e14bb325SJeff Bonwick 	for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++)
2633e14bb325SJeff Bonwick 		if (e2 == zio_error_rank[r2])
2634e14bb325SJeff Bonwick 			break;
263544cd46caSbillm 
2636e14bb325SJeff Bonwick 	return (r1 > r2 ? e1 : e2);
2637fa9e4066Sahrens }
2638fa9e4066Sahrens 
2639fa9e4066Sahrens /*
2640fa9e4066Sahrens  * ==========================================================================
2641e14bb325SJeff Bonwick  * I/O completion
2642fa9e4066Sahrens  * ==========================================================================
2643fa9e4066Sahrens  */
2644e14bb325SJeff Bonwick static int
2645e14bb325SJeff Bonwick zio_ready(zio_t *zio)
2646fa9e4066Sahrens {
2647e14bb325SJeff Bonwick 	blkptr_t *bp = zio->io_bp;
2648a3f829aeSBill Moore 	zio_t *pio, *pio_next;
2649fa9e4066Sahrens 
2650b24ab676SJeff Bonwick 	if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) ||
2651b24ab676SJeff Bonwick 	    zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_READY))
2652f5383399SBill Moore 		return (ZIO_PIPELINE_STOP);
2653fa9e4066Sahrens 
2654f5383399SBill Moore 	if (zio->io_ready) {
2655e14bb325SJeff Bonwick 		ASSERT(IO_IS_ALLOCATING(zio));
2656e14bb325SJeff Bonwick 		ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp));
2657e14bb325SJeff Bonwick 		ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0);
2658fa9e4066Sahrens 
2659e14bb325SJeff Bonwick 		zio->io_ready(zio);
2660e14bb325SJeff Bonwick 	}
2661fa9e4066Sahrens 
2662e14bb325SJeff Bonwick 	if (bp != NULL && bp != &zio->io_bp_copy)
2663e14bb325SJeff Bonwick 		zio->io_bp_copy = *bp;
2664fa9e4066Sahrens 
2665e14bb325SJeff Bonwick 	if (zio->io_error)
2666e14bb325SJeff Bonwick 		zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
2667fa9e4066Sahrens 
2668a3f829aeSBill Moore 	mutex_enter(&zio->io_lock);
2669a3f829aeSBill Moore 	zio->io_state[ZIO_WAIT_READY] = 1;
2670a3f829aeSBill Moore 	pio = zio_walk_parents(zio);
2671a3f829aeSBill Moore 	mutex_exit(&zio->io_lock);
2672a3f829aeSBill Moore 
2673a3f829aeSBill Moore 	/*
2674a3f829aeSBill Moore 	 * As we notify zio's parents, new parents could be added.
2675a3f829aeSBill Moore 	 * New parents go to the head of zio's io_parent_list, however,
2676a3f829aeSBill Moore 	 * so we will (correctly) not notify them.  The remainder of zio's
2677a3f829aeSBill Moore 	 * io_parent_list, from 'pio_next' onward, cannot change because
2678a3f829aeSBill Moore 	 * all parents must wait for us to be done before they can be done.
2679a3f829aeSBill Moore 	 */
2680a3f829aeSBill Moore 	for (; pio != NULL; pio = pio_next) {
2681a3f829aeSBill Moore 		pio_next = zio_walk_parents(zio);
2682e14bb325SJeff Bonwick 		zio_notify_parent(pio, zio, ZIO_WAIT_READY);
2683a3f829aeSBill Moore 	}
2684fa9e4066Sahrens 
2685b24ab676SJeff Bonwick 	if (zio->io_flags & ZIO_FLAG_NODATA) {
2686b24ab676SJeff Bonwick 		if (BP_IS_GANG(bp)) {
2687b24ab676SJeff Bonwick 			zio->io_flags &= ~ZIO_FLAG_NODATA;
2688b24ab676SJeff Bonwick 		} else {
2689b24ab676SJeff Bonwick 			ASSERT((uintptr_t)zio->io_data < SPA_MAXBLOCKSIZE);
2690b24ab676SJeff Bonwick 			zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES;
2691b24ab676SJeff Bonwick 		}
2692b24ab676SJeff Bonwick 	}
2693b24ab676SJeff Bonwick 
2694a33cae98STim Haley 	if (zio_injection_enabled &&
2695a33cae98STim Haley 	    zio->io_spa->spa_syncing_txg == zio->io_txg)
2696a33cae98STim Haley 		zio_handle_ignored_writes(zio);
2697a33cae98STim Haley 
2698e14bb325SJeff Bonwick 	return (ZIO_PIPELINE_CONTINUE);
2699fa9e4066Sahrens }
2700fa9e4066Sahrens 
2701e14bb325SJeff Bonwick static int
2702e14bb325SJeff Bonwick zio_done(zio_t *zio)
2703d63d470bSgw {
2704e14bb325SJeff Bonwick 	spa_t *spa = zio->io_spa;
2705e14bb325SJeff Bonwick 	zio_t *lio = zio->io_logical;
2706e14bb325SJeff Bonwick 	blkptr_t *bp = zio->io_bp;
2707e14bb325SJeff Bonwick 	vdev_t *vd = zio->io_vd;
2708e14bb325SJeff Bonwick 	uint64_t psize = zio->io_size;
2709a3f829aeSBill Moore 	zio_t *pio, *pio_next;
2710d63d470bSgw 
2711e14bb325SJeff Bonwick 	/*
2712f5383399SBill Moore 	 * If our children haven't all completed,
2713e14bb325SJeff Bonwick 	 * wait for them and then repeat this pipeline stage.
2714e14bb325SJeff Bonwick 	 */
2715e14bb325SJeff Bonwick 	if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE) ||
2716e14bb325SJeff Bonwick 	    zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE) ||
2717b24ab676SJeff Bonwick 	    zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE) ||
2718e14bb325SJeff Bonwick 	    zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_DONE))
2719e14bb325SJeff Bonwick 		return (ZIO_PIPELINE_STOP);
2720d63d470bSgw 
2721e14bb325SJeff Bonwick 	for (int c = 0; c < ZIO_CHILD_TYPES; c++)
2722e14bb325SJeff Bonwick 		for (int w = 0; w < ZIO_WAIT_TYPES; w++)
2723e14bb325SJeff Bonwick 			ASSERT(zio->io_children[c][w] == 0);
2724e14bb325SJeff Bonwick 
2725e14bb325SJeff Bonwick 	if (bp != NULL) {
2726e14bb325SJeff Bonwick 		ASSERT(bp->blk_pad[0] == 0);
2727e14bb325SJeff Bonwick 		ASSERT(bp->blk_pad[1] == 0);
2728e14bb325SJeff Bonwick 		ASSERT(bcmp(bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0 ||
2729a3f829aeSBill Moore 		    (bp == zio_unique_parent(zio)->io_bp));
2730e14bb325SJeff Bonwick 		if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(bp) &&
2731b24ab676SJeff Bonwick 		    zio->io_bp_override == NULL &&
2732e14bb325SJeff Bonwick 		    !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) {
2733e14bb325SJeff Bonwick 			ASSERT(!BP_SHOULD_BYTESWAP(bp));
2734b24ab676SJeff Bonwick 			ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(bp));
2735e14bb325SJeff Bonwick 			ASSERT(BP_COUNT_GANG(bp) == 0 ||
2736e14bb325SJeff Bonwick 			    (BP_COUNT_GANG(bp) == BP_GET_NDVAS(bp)));
2737e14bb325SJeff Bonwick 		}
2738e14bb325SJeff Bonwick 	}
2739fa9e4066Sahrens 
2740e14bb325SJeff Bonwick 	/*
2741b24ab676SJeff Bonwick 	 * If there were child vdev/gang/ddt errors, they apply to us now.
2742e14bb325SJeff Bonwick 	 */
2743e14bb325SJeff Bonwick 	zio_inherit_child_errors(zio, ZIO_CHILD_VDEV);
2744e14bb325SJeff Bonwick 	zio_inherit_child_errors(zio, ZIO_CHILD_GANG);
2745b24ab676SJeff Bonwick 	zio_inherit_child_errors(zio, ZIO_CHILD_DDT);
2746b24ab676SJeff Bonwick 
2747b24ab676SJeff Bonwick 	/*
2748b24ab676SJeff Bonwick 	 * If the I/O on the transformed data was successful, generate any
2749b24ab676SJeff Bonwick 	 * checksum reports now while we still have the transformed data.
2750b24ab676SJeff Bonwick 	 */
2751b24ab676SJeff Bonwick 	if (zio->io_error == 0) {
2752b24ab676SJeff Bonwick 		while (zio->io_cksum_report != NULL) {
2753b24ab676SJeff Bonwick 			zio_cksum_report_t *zcr = zio->io_cksum_report;
2754b24ab676SJeff Bonwick 			uint64_t align = zcr->zcr_align;
2755b24ab676SJeff Bonwick 			uint64_t asize = P2ROUNDUP(psize, align);
2756b24ab676SJeff Bonwick 			char *abuf = zio->io_data;
2757b24ab676SJeff Bonwick 
2758b24ab676SJeff Bonwick 			if (asize != psize) {
2759b24ab676SJeff Bonwick 				abuf = zio_buf_alloc(asize);
2760b24ab676SJeff Bonwick 				bcopy(zio->io_data, abuf, psize);
2761b24ab676SJeff Bonwick 				bzero(abuf + psize, asize - psize);
2762b24ab676SJeff Bonwick 			}
2763b24ab676SJeff Bonwick 
2764b24ab676SJeff Bonwick 			zio->io_cksum_report = zcr->zcr_next;
2765b24ab676SJeff Bonwick 			zcr->zcr_next = NULL;
2766b24ab676SJeff Bonwick 			zcr->zcr_finish(zcr, abuf);
2767b24ab676SJeff Bonwick 			zfs_ereport_free_checksum(zcr);
2768b24ab676SJeff Bonwick 
2769b24ab676SJeff Bonwick 			if (asize != psize)
2770b24ab676SJeff Bonwick 				zio_buf_free(abuf, asize);
2771b24ab676SJeff Bonwick 		}
2772b24ab676SJeff Bonwick 	}
2773e14bb325SJeff Bonwick 
2774e14bb325SJeff Bonwick 	zio_pop_transforms(zio);	/* note: may set zio->io_error */
2775e14bb325SJeff Bonwick 
2776e14bb325SJeff Bonwick 	vdev_stat_update(zio, psize);
2777e14bb325SJeff Bonwick 
2778e14bb325SJeff Bonwick 	if (zio->io_error) {
2779e14bb325SJeff Bonwick 		/*
2780e14bb325SJeff Bonwick 		 * If this I/O is attached to a particular vdev,
2781e14bb325SJeff Bonwick 		 * generate an error message describing the I/O failure
2782e14bb325SJeff Bonwick 		 * at the block level.  We ignore these errors if the
2783e14bb325SJeff Bonwick 		 * device is currently unavailable.
2784e14bb325SJeff Bonwick 		 */
2785e14bb325SJeff Bonwick 		if (zio->io_error != ECKSUM && vd != NULL && !vdev_is_dead(vd))
2786e14bb325SJeff Bonwick 			zfs_ereport_post(FM_EREPORT_ZFS_IO, spa, vd, zio, 0, 0);
2787e14bb325SJeff Bonwick 
27888f18d1faSGeorge Wilson 		if ((zio->io_error == EIO || !(zio->io_flags &
27898f18d1faSGeorge Wilson 		    (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) &&
27908f18d1faSGeorge Wilson 		    zio == lio) {
2791e14bb325SJeff Bonwick 			/*
2792e14bb325SJeff Bonwick 			 * For logical I/O requests, tell the SPA to log the
2793e14bb325SJeff Bonwick 			 * error and generate a logical data ereport.
2794e14bb325SJeff Bonwick 			 */
2795e14bb325SJeff Bonwick 			spa_log_error(spa, zio);
2796e14bb325SJeff Bonwick 			zfs_ereport_post(FM_EREPORT_ZFS_DATA, spa, NULL, zio,
2797e14bb325SJeff Bonwick 			    0, 0);
2798e14bb325SJeff Bonwick 		}
2799e14bb325SJeff Bonwick 	}
2800fa9e4066Sahrens 
2801e14bb325SJeff Bonwick 	if (zio->io_error && zio == lio) {
2802e14bb325SJeff Bonwick 		/*
2803e14bb325SJeff Bonwick 		 * Determine whether zio should be reexecuted.  This will
2804e14bb325SJeff Bonwick 		 * propagate all the way to the root via zio_notify_parent().
2805e14bb325SJeff Bonwick 		 */
2806e14bb325SJeff Bonwick 		ASSERT(vd == NULL && bp != NULL);
2807b24ab676SJeff Bonwick 		ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
2808e14bb325SJeff Bonwick 
2809b24ab676SJeff Bonwick 		if (IO_IS_ALLOCATING(zio) &&
2810b24ab676SJeff Bonwick 		    !(zio->io_flags & ZIO_FLAG_CANFAIL)) {
2811e14bb325SJeff Bonwick 			if (zio->io_error != ENOSPC)
2812e14bb325SJeff Bonwick 				zio->io_reexecute |= ZIO_REEXECUTE_NOW;
2813e14bb325SJeff Bonwick 			else
2814e14bb325SJeff Bonwick 				zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
2815b24ab676SJeff Bonwick 		}
2816e14bb325SJeff Bonwick 
2817e14bb325SJeff Bonwick 		if ((zio->io_type == ZIO_TYPE_READ ||
2818e14bb325SJeff Bonwick 		    zio->io_type == ZIO_TYPE_FREE) &&
281944ecc532SGeorge Wilson 		    !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) &&
2820e14bb325SJeff Bonwick 		    zio->io_error == ENXIO &&
2821b16da2e2SGeorge Wilson 		    spa_load_state(spa) == SPA_LOAD_NONE &&
2822e14bb325SJeff Bonwick 		    spa_get_failmode(spa) != ZIO_FAILURE_MODE_CONTINUE)
2823e14bb325SJeff Bonwick 			zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
2824e14bb325SJeff Bonwick 
2825e14bb325SJeff Bonwick 		if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute)
2826e14bb325SJeff Bonwick 			zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
282722fe2c88SJonathan Adams 
282822fe2c88SJonathan Adams 		/*
282922fe2c88SJonathan Adams 		 * Here is a possibly good place to attempt to do
283022fe2c88SJonathan Adams 		 * either combinatorial reconstruction or error correction
283122fe2c88SJonathan Adams 		 * based on checksums.  It also might be a good place
283222fe2c88SJonathan Adams 		 * to send out preliminary ereports before we suspend
283322fe2c88SJonathan Adams 		 * processing.
283422fe2c88SJonathan Adams 		 */
2835d63d470bSgw 	}
2836d63d470bSgw 
283767bd71c6Sperrin 	/*
2838e14bb325SJeff Bonwick 	 * If there were logical child errors, they apply to us now.
2839e14bb325SJeff Bonwick 	 * We defer this until now to avoid conflating logical child
2840e14bb325SJeff Bonwick 	 * errors with errors that happened to the zio itself when
2841e14bb325SJeff Bonwick 	 * updating vdev stats and reporting FMA events above.
284267bd71c6Sperrin 	 */
2843e14bb325SJeff Bonwick 	zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL);
28448654d025Sperrin 
2845b24ab676SJeff Bonwick 	if ((zio->io_error || zio->io_reexecute) &&
2846b24ab676SJeff Bonwick 	    IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio &&
2847b24ab676SJeff Bonwick 	    !(zio->io_flags & ZIO_FLAG_IO_REWRITE))
2848f5383399SBill Moore 		zio_dva_unallocate(zio, zio->io_gang_tree, bp);
2849f5383399SBill Moore 
2850f5383399SBill Moore 	zio_gang_tree_free(&zio->io_gang_tree);
2851f5383399SBill Moore 
285233a372edSGeorge Wilson 	/*
285333a372edSGeorge Wilson 	 * Godfather I/Os should never suspend.
285433a372edSGeorge Wilson 	 */
285533a372edSGeorge Wilson 	if ((zio->io_flags & ZIO_FLAG_GODFATHER) &&
285633a372edSGeorge Wilson 	    (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND))
285733a372edSGeorge Wilson 		zio->io_reexecute = 0;
285833a372edSGeorge Wilson 
285933a372edSGeorge Wilson 	if (zio->io_reexecute) {
2860e14bb325SJeff Bonwick 		/*
2861e14bb325SJeff Bonwick 		 * This is a logical I/O that wants to reexecute.
2862e14bb325SJeff Bonwick 		 *
2863e14bb325SJeff Bonwick 		 * Reexecute is top-down.  When an i/o fails, if it's not
2864e14bb325SJeff Bonwick 		 * the root, it simply notifies its parent and sticks around.
2865e14bb325SJeff Bonwick 		 * The parent, seeing that it still has children in zio_done(),
2866e14bb325SJeff Bonwick 		 * does the same.  This percolates all the way up to the root.
2867e14bb325SJeff Bonwick 		 * The root i/o will reexecute or suspend the entire tree.
2868e14bb325SJeff Bonwick 		 *
2869e14bb325SJeff Bonwick 		 * This approach ensures that zio_reexecute() honors
2870e14bb325SJeff Bonwick 		 * all the original i/o dependency relationships, e.g.
2871e14bb325SJeff Bonwick 		 * parents not executing until children are ready.
2872e14bb325SJeff Bonwick 		 */
2873e14bb325SJeff Bonwick 		ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
2874fa9e4066Sahrens 
2875f5383399SBill Moore 		zio->io_gang_leader = NULL;
2876e14bb325SJeff Bonwick 
2877a3f829aeSBill Moore 		mutex_enter(&zio->io_lock);
2878a3f829aeSBill Moore 		zio->io_state[ZIO_WAIT_DONE] = 1;
2879a3f829aeSBill Moore 		mutex_exit(&zio->io_lock);
2880a3f829aeSBill Moore 
288154d692b7SGeorge Wilson 		/*
288254d692b7SGeorge Wilson 		 * "The Godfather" I/O monitors its children but is
288354d692b7SGeorge Wilson 		 * not a true parent to them. It will track them through
288454d692b7SGeorge Wilson 		 * the pipeline but severs its ties whenever they get into
288554d692b7SGeorge Wilson 		 * trouble (e.g. suspended). This allows "The Godfather"
288654d692b7SGeorge Wilson 		 * I/O to return status without blocking.
288754d692b7SGeorge Wilson 		 */
288854d692b7SGeorge Wilson 		for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) {
288954d692b7SGeorge Wilson 			zio_link_t *zl = zio->io_walk_link;
289054d692b7SGeorge Wilson 			pio_next = zio_walk_parents(zio);
289154d692b7SGeorge Wilson 
289254d692b7SGeorge Wilson 			if ((pio->io_flags & ZIO_FLAG_GODFATHER) &&
289354d692b7SGeorge Wilson 			    (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) {
289454d692b7SGeorge Wilson 				zio_remove_child(pio, zio, zl);
289554d692b7SGeorge Wilson 				zio_notify_parent(pio, zio, ZIO_WAIT_DONE);
289654d692b7SGeorge Wilson 			}
289754d692b7SGeorge Wilson 		}
289854d692b7SGeorge Wilson 
2899a3f829aeSBill Moore 		if ((pio = zio_unique_parent(zio)) != NULL) {
2900e14bb325SJeff Bonwick 			/*
2901e14bb325SJeff Bonwick 			 * We're not a root i/o, so there's nothing to do
2902e14bb325SJeff Bonwick 			 * but notify our parent.  Don't propagate errors
2903e14bb325SJeff Bonwick 			 * upward since we haven't permanently failed yet.
2904e14bb325SJeff Bonwick 			 */
290533a372edSGeorge Wilson 			ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER));
2906e14bb325SJeff Bonwick 			zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE;
2907e14bb325SJeff Bonwick 			zio_notify_parent(pio, zio, ZIO_WAIT_DONE);
2908e14bb325SJeff Bonwick 		} else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) {
2909e14bb325SJeff Bonwick 			/*
2910e14bb325SJeff Bonwick 			 * We'd fail again if we reexecuted now, so suspend
2911e14bb325SJeff Bonwick 			 * until conditions improve (e.g. device comes online).
2912e14bb325SJeff Bonwick 			 */
2913e14bb325SJeff Bonwick 			zio_suspend(spa, zio);
2914e14bb325SJeff Bonwick 		} else {
2915e14bb325SJeff Bonwick 			/*
2916e14bb325SJeff Bonwick 			 * Reexecution is potentially a huge amount of work.
2917e14bb325SJeff Bonwick 			 * Hand it off to the otherwise-unused claim taskq.
2918e14bb325SJeff Bonwick 			 */
29195aeb9474SGarrett D'Amore 			ASSERT(zio->io_tqent.tqent_next == NULL);
29205aeb9474SGarrett D'Amore 			(void) taskq_dispatch_ent(
2921e14bb325SJeff Bonwick 			    spa->spa_zio_taskq[ZIO_TYPE_CLAIM][ZIO_TASKQ_ISSUE],
29225aeb9474SGarrett D'Amore 			    (task_func_t *)zio_reexecute, zio, 0,
29235aeb9474SGarrett D'Amore 			    &zio->io_tqent);
2924e14bb325SJeff Bonwick 		}
2925e14bb325SJeff Bonwick 		return (ZIO_PIPELINE_STOP);
2926fa9e4066Sahrens 	}
2927fa9e4066Sahrens 
2928b24ab676SJeff Bonwick 	ASSERT(zio->io_child_count == 0);
292933a372edSGeorge Wilson 	ASSERT(zio->io_reexecute == 0);
2930e14bb325SJeff Bonwick 	ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL));
2931fa9e4066Sahrens 
2932b24ab676SJeff Bonwick 	/*
2933b24ab676SJeff Bonwick 	 * Report any checksum errors, since the I/O is complete.
2934b24ab676SJeff Bonwick 	 */
293522fe2c88SJonathan Adams 	while (zio->io_cksum_report != NULL) {
2936b24ab676SJeff Bonwick 		zio_cksum_report_t *zcr = zio->io_cksum_report;
2937b24ab676SJeff Bonwick 		zio->io_cksum_report = zcr->zcr_next;
2938b24ab676SJeff Bonwick 		zcr->zcr_next = NULL;
2939b24ab676SJeff Bonwick 		zcr->zcr_finish(zcr, NULL);
2940b24ab676SJeff Bonwick 		zfs_ereport_free_checksum(zcr);
294122fe2c88SJonathan Adams 	}
294222fe2c88SJonathan Adams 
2943a3f829aeSBill Moore 	/*
2944a3f829aeSBill Moore 	 * It is the responsibility of the done callback to ensure that this
2945a3f829aeSBill Moore 	 * particular zio is no longer discoverable for adoption, and as
2946a3f829aeSBill Moore 	 * such, cannot acquire any new parents.
2947a3f829aeSBill Moore 	 */
2948e14bb325SJeff Bonwick 	if (zio->io_done)
2949e14bb325SJeff Bonwick 		zio->io_done(zio);
2950fa9e4066Sahrens 
2951a3f829aeSBill Moore 	mutex_enter(&zio->io_lock);
2952a3f829aeSBill Moore 	zio->io_state[ZIO_WAIT_DONE] = 1;
2953a3f829aeSBill Moore 	mutex_exit(&zio->io_lock);
2954fa9e4066Sahrens 
2955a3f829aeSBill Moore 	for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) {
2956a3f829aeSBill Moore 		zio_link_t *zl = zio->io_walk_link;
2957a3f829aeSBill Moore 		pio_next = zio_walk_parents(zio);
2958a3f829aeSBill Moore 		zio_remove_child(pio, zio, zl);
2959e14bb325SJeff Bonwick 		zio_notify_parent(pio, zio, ZIO_WAIT_DONE);
2960e14bb325SJeff Bonwick 	}
2961fa9e4066Sahrens 
2962e14bb325SJeff Bonwick 	if (zio->io_waiter != NULL) {
2963e14bb325SJeff Bonwick 		mutex_enter(&zio->io_lock);
2964e14bb325SJeff Bonwick 		zio->io_executor = NULL;
2965e14bb325SJeff Bonwick 		cv_broadcast(&zio->io_cv);
2966e14bb325SJeff Bonwick 		mutex_exit(&zio->io_lock);
2967e14bb325SJeff Bonwick 	} else {
2968e14bb325SJeff Bonwick 		zio_destroy(zio);
2969e14bb325SJeff Bonwick 	}
2970fa9e4066Sahrens 
2971e14bb325SJeff Bonwick 	return (ZIO_PIPELINE_STOP);
2972fa9e4066Sahrens }
297346341222Sperrin 
297446341222Sperrin /*
2975e14bb325SJeff Bonwick  * ==========================================================================
2976e14bb325SJeff Bonwick  * I/O pipeline definition
2977e14bb325SJeff Bonwick  * ==========================================================================
297846341222Sperrin  */
2979b24ab676SJeff Bonwick static zio_pipe_stage_t *zio_pipeline[] = {
2980e14bb325SJeff Bonwick 	NULL,
2981e14bb325SJeff Bonwick 	zio_read_bp_init,
2982b24ab676SJeff Bonwick 	zio_free_bp_init,
2983b24ab676SJeff Bonwick 	zio_issue_async,
2984e14bb325SJeff Bonwick 	zio_write_bp_init,
2985e14bb325SJeff Bonwick 	zio_checksum_generate,
2986b24ab676SJeff Bonwick 	zio_ddt_read_start,
2987b24ab676SJeff Bonwick 	zio_ddt_read_done,
2988b24ab676SJeff Bonwick 	zio_ddt_write,
2989b24ab676SJeff Bonwick 	zio_ddt_free,
2990e14bb325SJeff Bonwick 	zio_gang_assemble,
2991e14bb325SJeff Bonwick 	zio_gang_issue,
2992e14bb325SJeff Bonwick 	zio_dva_allocate,
2993e14bb325SJeff Bonwick 	zio_dva_free,
2994e14bb325SJeff Bonwick 	zio_dva_claim,
2995e14bb325SJeff Bonwick 	zio_ready,
2996e14bb325SJeff Bonwick 	zio_vdev_io_start,
2997e14bb325SJeff Bonwick 	zio_vdev_io_done,
2998e14bb325SJeff Bonwick 	zio_vdev_io_assess,
2999e14bb325SJeff Bonwick 	zio_checksum_verify,
3000e14bb325SJeff Bonwick 	zio_done
3001e14bb325SJeff Bonwick };
3002ad135b5dSChristopher Siden 
3003ad135b5dSChristopher Siden /* dnp is the dnode for zb1->zb_object */
3004ad135b5dSChristopher Siden boolean_t
3005ad135b5dSChristopher Siden zbookmark_is_before(const dnode_phys_t *dnp, const zbookmark_t *zb1,
3006ad135b5dSChristopher Siden     const zbookmark_t *zb2)
3007ad135b5dSChristopher Siden {
3008ad135b5dSChristopher Siden 	uint64_t zb1nextL0, zb2thisobj;
3009ad135b5dSChristopher Siden 
3010ad135b5dSChristopher Siden 	ASSERT(zb1->zb_objset == zb2->zb_objset);
3011ad135b5dSChristopher Siden 	ASSERT(zb2->zb_level == 0);
3012ad135b5dSChristopher Siden 
3013ad135b5dSChristopher Siden 	/*
3014ad135b5dSChristopher Siden 	 * A bookmark in the deadlist is considered to be after
3015ad135b5dSChristopher Siden 	 * everything else.
3016ad135b5dSChristopher Siden 	 */
3017ad135b5dSChristopher Siden 	if (zb2->zb_object == DMU_DEADLIST_OBJECT)
3018ad135b5dSChristopher Siden 		return (B_TRUE);
3019ad135b5dSChristopher Siden 
3020ad135b5dSChristopher Siden 	/* The objset_phys_t isn't before anything. */
3021ad135b5dSChristopher Siden 	if (dnp == NULL)
3022ad135b5dSChristopher Siden 		return (B_FALSE);
3023ad135b5dSChristopher Siden 
3024ad135b5dSChristopher Siden 	zb1nextL0 = (zb1->zb_blkid + 1) <<
3025ad135b5dSChristopher Siden 	    ((zb1->zb_level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT));
3026ad135b5dSChristopher Siden 
3027ad135b5dSChristopher Siden 	zb2thisobj = zb2->zb_object ? zb2->zb_object :
3028ad135b5dSChristopher Siden 	    zb2->zb_blkid << (DNODE_BLOCK_SHIFT - DNODE_SHIFT);
3029ad135b5dSChristopher Siden 
3030ad135b5dSChristopher Siden 	if (zb1->zb_object == DMU_META_DNODE_OBJECT) {
3031ad135b5dSChristopher Siden 		uint64_t nextobj = zb1nextL0 *
3032ad135b5dSChristopher Siden 		    (dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT) >> DNODE_SHIFT;
3033ad135b5dSChristopher Siden 		return (nextobj <= zb2thisobj);
3034ad135b5dSChristopher Siden 	}
3035ad135b5dSChristopher Siden 
3036ad135b5dSChristopher Siden 	if (zb1->zb_object < zb2thisobj)
3037ad135b5dSChristopher Siden 		return (B_TRUE);
3038ad135b5dSChristopher Siden 	if (zb1->zb_object > zb2thisobj)
3039ad135b5dSChristopher Siden 		return (B_FALSE);
3040ad135b5dSChristopher Siden 	if (zb2->zb_object == DMU_META_DNODE_OBJECT)
3041ad135b5dSChristopher Siden 		return (B_FALSE);
3042ad135b5dSChristopher Siden 	return (zb1nextL0 <= zb2->zb_blkid);
3043ad135b5dSChristopher Siden }
3044