/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright 2015 Joyent, Inc. */ /* * Copyright (c) 1987, 2010, Oracle and/or its affiliates. All rights reserved. */ /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ /* All Rights Reserved */ /* * University Copyright- Copyright (c) 1982, 1986, 1988 * The Regents of the University of California * All Rights Reserved * * University Acknowledgment- Portions of this document are derived from * software developed by the University of California, Berkeley, and its * contributors. */ /* * Each physical swap area has an associated bitmap representing * its physical storage. The bitmap records which swap slots are * currently allocated or freed. Allocation is done by searching * through the bitmap for the first free slot. Thus, there's * no linear relation between offset within the swap device and the * address (within its segment(s)) of the page that the slot backs; * instead, it's an arbitrary one-to-one mapping. * * Associated with each swap area is a swapinfo structure. These * structures are linked into a linear list that determines the * ordering of swap areas in the logical swap device. Each contains a * pointer to the corresponding bitmap, the area's size, and its * associated vnode. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * To balance the load among multiple swap areas, we don't allow * more than swap_maxcontig allocations to be satisfied from a * single swap area before moving on to the next swap area. This * effectively "interleaves" allocations among the many swap areas. */ int swap_maxcontig; /* set by anon_init() to 1 Mb */ #define MINIROOTSIZE 12000 /* ~6 Meg XXX */ /* * XXX - this lock is a kludge. It serializes some aspects of swapadd() and * swapdel() (namely VOP_OPEN, VOP_CLOSE, VN_RELE). It protects against * somebody swapadd'ing and getting swap slots from a vnode, while someone * else is in the process of closing or rele'ing it. */ static kmutex_t swap_lock; kmutex_t swapinfo_lock; /* * protected by the swapinfo_lock */ extern struct swapinfo *swapinfo; static struct swapinfo *silast; static int nswapfiles; static u_offset_t swap_getoff(struct swapinfo *); static int swapadd(struct vnode *, ulong_t, ulong_t, char *); static int swapdel(struct vnode *, ulong_t); static int swapslot_free(struct vnode *, u_offset_t, struct swapinfo *); /* * swap device bitmap allocation macros */ #define MAPSHIFT 5 #define NBBW (NBPW * NBBY) /* number of bits per word */ #define TESTBIT(map, i) (((map)[(i) >> MAPSHIFT] & (1 << (i) % NBBW))) #define SETBIT(map, i) (((map)[(i) >> MAPSHIFT] |= (1 << (i) % NBBW))) #define CLEARBIT(map, i) (((map)[(i) >> MAPSHIFT] &= ~(1 << (i) % NBBW))) int swap_debug = 0; /* set for debug printf's */ int swap_verify = 0; /* set to verify slots when freeing and allocating */ uint_t swapalloc_maxcontig; /* * Allocate a range of up to *lenp contiguous slots (page) from a physical * swap device. Flags are one of: * SA_NOT Must have a slot from a physical swap device other than the * the one containing input (*vpp, *offp). * Less slots than requested may be returned. *lenp allocated slots are * returned starting at *offp on *vpp. * Returns 1 for a successful allocation, 0 for couldn't allocate any slots. */ int swap_phys_alloc( struct vnode **vpp, u_offset_t *offp, size_t *lenp, uint_t flags) { struct swapinfo *sip; offset_t soff, noff; size_t len; mutex_enter(&swapinfo_lock); sip = silast; /* Find a desirable physical device and allocate from it. */ do { if (sip == NULL) break; if (!(sip->si_flags & ST_INDEL) && (spgcnt_t)sip->si_nfpgs > 0) { /* Caller wants other than specified swap device */ if (flags & SA_NOT) { if (*vpp != sip->si_vp || *offp < sip->si_soff || *offp >= sip->si_eoff) goto found; /* Caller is loose, will take anything */ } else goto found; } else if (sip->si_nfpgs == 0) sip->si_allocs = 0; if ((sip = sip->si_next) == NULL) sip = swapinfo; } while (sip != silast); mutex_exit(&swapinfo_lock); return (0); found: soff = swap_getoff(sip); sip->si_nfpgs--; if (soff == -1) panic("swap_alloc: swap_getoff failed!"); for (len = PAGESIZE; len < *lenp; len += PAGESIZE) { if (sip->si_nfpgs == 0) break; if (swapalloc_maxcontig && len >= swapalloc_maxcontig) break; noff = swap_getoff(sip); if (noff == -1) { break; } else if (noff != soff + len) { CLEARBIT(sip->si_swapslots, btop(noff - sip->si_soff)); break; } sip->si_nfpgs--; } *vpp = sip->si_vp; *offp = soff; *lenp = len; ASSERT((spgcnt_t)sip->si_nfpgs >= 0); sip->si_allocs += btop(len); if (sip->si_allocs >= swap_maxcontig) { sip->si_allocs = 0; if ((silast = sip->si_next) == NULL) silast = swapinfo; } TRACE_2(TR_FAC_VM, TR_SWAP_ALLOC, "swap_alloc:sip %p offset %lx", sip, soff); mutex_exit(&swapinfo_lock); return (1); } int swap_backsearch = 0; /* * Get a free offset on swap device sip. * Return >=0 offset if succeeded, -1 for failure. */ static u_offset_t swap_getoff(struct swapinfo *sip) { uint_t *sp, *ep; size_t aoff, boff, poff, slotnumber; ASSERT(MUTEX_HELD(&swapinfo_lock)); sip->si_alloccnt++; for (sp = &sip->si_swapslots[sip->si_hint >> MAPSHIFT], ep = &sip->si_swapslots[sip->si_mapsize / NBPW]; sp < ep; sp++) { if (*sp != (uint_t)0xffffffff) goto foundentry; else sip->si_checkcnt++; } SWAP_PRINT(SW_ALLOC, "swap_getoff: couldn't find slot from hint %ld to end\n", sip->si_hint, 0, 0, 0, 0); /* * Go backwards? Check for faster method XXX */ if (swap_backsearch) { for (sp = &sip->si_swapslots[sip->si_hint >> MAPSHIFT], ep = sip->si_swapslots; sp > ep; sp--) { if (*sp != (uint_t)0xffffffff) goto foundentry; else sip->si_checkcnt++; } } else { for (sp = sip->si_swapslots, ep = &sip->si_swapslots[sip->si_hint >> MAPSHIFT]; sp < ep; sp++) { if (*sp != (uint_t)0xffffffff) goto foundentry; else sip->si_checkcnt++; } } if (*sp == 0xffffffff) { cmn_err(CE_WARN, "No free swap slots!"); return ((u_offset_t)-1); } foundentry: /* * aoff is the page number offset (in bytes) of the si_swapslots * array element containing a free page * * boff is the page number offset of the free page * (i.e. cleared bit) in si_swapslots[aoff]. */ aoff = ((char *)sp - (char *)sip->si_swapslots) * NBBY; for (boff = (sip->si_hint % NBBW); boff < NBBW; boff++) { if (!TESTBIT(sip->si_swapslots, aoff + boff)) goto foundslot; else sip->si_checkcnt++; } for (boff = 0; boff < (sip->si_hint % NBBW); boff++) { if (!TESTBIT(sip->si_swapslots, aoff + boff)) goto foundslot; else sip->si_checkcnt++; } panic("swap_getoff: didn't find slot in word hint %ld", sip->si_hint); foundslot: /* * Return the offset of the free page in swap device. * Convert page number of byte offset and add starting * offset of swap device. */ slotnumber = aoff + boff; SWAP_PRINT(SW_ALLOC, "swap_getoff: allocating slot %ld\n", slotnumber, 0, 0, 0, 0); poff = ptob(slotnumber); if (poff + sip->si_soff >= sip->si_eoff) printf("ptob(aoff(%ld) + boff(%ld))(%ld) >= eoff(%ld)\n", aoff, boff, ptob(slotnumber), (long)sip->si_eoff); ASSERT(poff < sip->si_eoff); /* * We could verify here that the slot isn't already allocated * by looking through all the anon slots. */ SETBIT(sip->si_swapslots, slotnumber); sip->si_hint = slotnumber + 1; /* hint = next slot */ return (poff + sip->si_soff); } /* * Free a swap page. */ void swap_phys_free(struct vnode *vp, u_offset_t off, size_t len) { struct swapinfo *sip; ssize_t pagenumber, npage; mutex_enter(&swapinfo_lock); sip = swapinfo; do { if (sip->si_vp == vp && sip->si_soff <= off && off < sip->si_eoff) { for (pagenumber = btop(off - sip->si_soff), npage = btop(len) + pagenumber; pagenumber < npage; pagenumber++) { SWAP_PRINT(SW_ALLOC, "swap_phys_free: freeing slot %ld on " "sip %p\n", pagenumber, sip, 0, 0, 0); if (!TESTBIT(sip->si_swapslots, pagenumber)) { panic( "swap_phys_free: freeing free slot " "%p,%lx\n", (void *)vp, ptob(pagenumber) + sip->si_soff); } CLEARBIT(sip->si_swapslots, pagenumber); sip->si_nfpgs++; } ASSERT(sip->si_nfpgs <= sip->si_npgs); mutex_exit(&swapinfo_lock); return; } } while ((sip = sip->si_next) != NULL); panic("swap_phys_free"); /*NOTREACHED*/ } /* * Return the anon struct corresponding for the given * if it is part of the virtual swap device. * Return the anon struct if found, otherwise NULL. */ struct anon * swap_anon(struct vnode *vp, u_offset_t off) { struct anon *ap; ASSERT(MUTEX_HELD(AH_MUTEX(vp, off))); for (ap = anon_hash[ANON_HASH(vp, off)]; ap != NULL; ap = ap->an_hash) { if (ap->an_vp == vp && ap->an_off == off) return (ap); } return (NULL); } /* * Determine if the vp offset range overlap a swap device. */ int swap_in_range(struct vnode *vp, u_offset_t offset, size_t len) { struct swapinfo *sip; u_offset_t eoff; eoff = offset + len; ASSERT(eoff > offset); mutex_enter(&swapinfo_lock); sip = swapinfo; if (vp && sip) { do { if (vp != sip->si_vp || eoff <= sip->si_soff || offset >= sip->si_eoff) continue; mutex_exit(&swapinfo_lock); return (1); } while ((sip = sip->si_next) != NULL); } mutex_exit(&swapinfo_lock); return (0); } /* * See if name is one of our swap files * even though lookupname failed. * This can be used by swapdel to delete * swap resources on remote machines * where the link has gone down. */ static struct vnode * swapdel_byname( char *name, /* pathname to delete */ ulong_t lowblk) /* Low block number of area to delete */ { struct swapinfo **sipp, *osip; u_offset_t soff; /* * Find the swap file entry for the file to * be deleted. Skip any entries that are in * transition. */ soff = ptob(btopr(lowblk << SCTRSHFT)); /* must be page aligned */ mutex_enter(&swapinfo_lock); for (sipp = &swapinfo; (osip = *sipp) != NULL; sipp = &osip->si_next) { if ((strcmp(osip->si_pname, name) == 0) && (osip->si_soff == soff) && (osip->si_flags == 0)) { struct vnode *vp = osip->si_vp; VN_HOLD(vp); mutex_exit(&swapinfo_lock); return (vp); } } mutex_exit(&swapinfo_lock); return (NULL); } /* * New system call to manipulate swap files. */ int swapctl(int sc_cmd, void *sc_arg, int *rv) { struct swapinfo *sip, *csip, *tsip; int error = 0; struct swapent st, *ust; struct swapres sr; struct vnode *vp; int cnt = 0; int tmp_nswapfiles; int nswap; int length, nlen; int gplen = 0, plen; char *swapname; char *pname; char *tpname; struct anoninfo ai; spgcnt_t avail; int global = INGLOBALZONE(curproc); struct zone *zp = curproc->p_zone; /* * When running in a zone we want to hide the details of the swap * devices: we report there only being one swap device named "swap" * having a size equal to the sum of the sizes of all real swap devices * on the system. */ switch (sc_cmd) { case SC_GETNSWP: if (global) *rv = nswapfiles; else *rv = 1; return (0); case SC_AINFO: /* * Return anoninfo information with these changes: * ani_max = maximum amount of swap space * (including potentially available physical memory) * ani_free = amount of unallocated anonymous memory * (some of which might be reserved and including * potentially available physical memory) * ani_resv = amount of claimed (reserved) anonymous memory */ avail = MAX((spgcnt_t)(availrmem - swapfs_minfree), 0); ai.ani_max = (k_anoninfo.ani_max + k_anoninfo.ani_mem_resv) + avail; /* Update ani_free */ set_anoninfo(); ai.ani_free = k_anoninfo.ani_free + avail; ai.ani_resv = k_anoninfo.ani_phys_resv + k_anoninfo.ani_mem_resv; if (!global && zp->zone_max_swap_ctl != UINT64_MAX) { /* * We're in a non-global zone with a swap cap. We * always report the system-wide values for the global * zone, even though it too can have a swap cap. */ /* * For a swap-capped zone, the numbers are contrived * since we don't have a correct value of 'reserved' * for the zone. * * The ani_max value is always the zone's swap cap. * * The ani_free value is always the difference between * the cap and the amount of swap in use by the zone. * * The ani_resv value is typically set to be the amount * of swap in use by the zone, but can be adjusted * upwards to indicate how much swap is currently * unavailable to that zone due to usage by entities * outside the zone. * * This works as follows. * * In the 'swap -s' output, the data is displayed * as follows: * allocated = ani_max - ani_free * reserved = ani_resv - allocated * available = ani_max - ani_resv * * Taking a contrived example, if the swap cap is 100 * and the amount of swap used by the zone is 75, this * gives: * allocated = ani_max - ani_free = 100 - 25 = 75 * reserved = ani_resv - allocated = 75 - 75 = 0 * available = ani_max - ani_resv = 100 - 75 = 25 * * In this typical case, you can see that the 'swap -s' * 'reserved' will always be 0 inside a swap capped * zone. * * However, if the system as a whole has less free * swap than the zone limits allow, then we adjust * the ani_resv value up so that it is the difference * between the zone cap and the amount of free system * swap. Taking the above example, but when the * system as a whole only has 20 of swap available, we * get an ani_resv of 100 - 20 = 80. This gives: * allocated = ani_max - ani_free = 100 - 25 = 75 * reserved = ani_resv - allocated = 80 - 75 = 5 * available = ani_max - ani_resv = 100 - 80 = 20 * * In this case, you can see how the ani_resv value is * tweaked up to make the 'swap -s' numbers work inside * the zone. */ rctl_qty_t cap, used; pgcnt_t pgcap, sys_avail; mutex_enter(&zp->zone_mem_lock); cap = zp->zone_max_swap_ctl; used = zp->zone_max_swap; mutex_exit(&zp->zone_mem_lock); pgcap = MIN(btop(cap), ai.ani_max); ai.ani_free = pgcap - btop(used); /* Get the system-wide swap currently available. */ sys_avail = ai.ani_max - ai.ani_resv; if (sys_avail < ai.ani_free) ai.ani_resv = pgcap - sys_avail; else ai.ani_resv = btop(used); ai.ani_max = pgcap; } if (copyout(&ai, sc_arg, sizeof (struct anoninfo)) != 0) return (EFAULT); return (0); case SC_LIST: if (copyin(sc_arg, &length, sizeof (int)) != 0) return (EFAULT); if (!global) { struct swapent st; char *swappath = "swap"; if (length < 1) return (ENOMEM); ust = (swapent_t *)((swaptbl_t *)sc_arg)->swt_ent; if (copyin(ust, &st, sizeof (swapent_t)) != 0) return (EFAULT); st.ste_start = PAGESIZE >> SCTRSHFT; st.ste_length = (off_t)0; st.ste_pages = 0; st.ste_free = 0; st.ste_flags = 0; mutex_enter(&swapinfo_lock); for (sip = swapinfo, nswap = 0; sip != NULL && nswap < nswapfiles; sip = sip->si_next, nswap++) { st.ste_length += (sip->si_eoff - sip->si_soff) >> SCTRSHFT; st.ste_pages += sip->si_npgs; st.ste_free += sip->si_nfpgs; } mutex_exit(&swapinfo_lock); if (zp->zone_max_swap_ctl != UINT64_MAX) { rctl_qty_t cap, used; mutex_enter(&zp->zone_mem_lock); cap = zp->zone_max_swap_ctl; used = zp->zone_max_swap; mutex_exit(&zp->zone_mem_lock); st.ste_length = MIN(cap, st.ste_length); st.ste_pages = MIN(btop(cap), st.ste_pages); st.ste_free = MIN(st.ste_pages - btop(used), st.ste_free); } if (copyout(&st, ust, sizeof (swapent_t)) != 0 || copyout(swappath, st.ste_path, strlen(swappath) + 1) != 0) { return (EFAULT); } *rv = 1; return (0); } beginning: mutex_enter(&swapinfo_lock); tmp_nswapfiles = nswapfiles; mutex_exit(&swapinfo_lock); /* * Return early if there are no swap entries to report: */ if (tmp_nswapfiles < 1) { *rv = 0; return (0); } /* Return an error if not enough space for the whole table. */ if (length < tmp_nswapfiles) return (ENOMEM); /* * Get memory to hold the swap entries and their names. We'll * copy the real entries into these and then copy these out. * Allocating the pathname memory is only a guess so we may * find that we need more and have to do it again. * All this is because we have to hold the anon lock while * traversing the swapinfo list, and we can't be doing copyouts * and/or kmem_alloc()s during this. */ csip = kmem_zalloc(tmp_nswapfiles * sizeof (struct swapinfo), KM_SLEEP); retry: nlen = tmp_nswapfiles * (gplen += 100); pname = kmem_zalloc(nlen, KM_SLEEP); mutex_enter(&swapinfo_lock); if (tmp_nswapfiles != nswapfiles) { mutex_exit(&swapinfo_lock); kmem_free(pname, nlen); kmem_free(csip, tmp_nswapfiles * sizeof (struct swapinfo)); gplen = 0; goto beginning; } for (sip = swapinfo, tsip = csip, tpname = pname, nswap = 0; sip && nswap < tmp_nswapfiles; sip = sip->si_next, tsip++, tpname += plen, nswap++) { plen = sip->si_pnamelen; if (tpname + plen - pname > nlen) { mutex_exit(&swapinfo_lock); kmem_free(pname, nlen); goto retry; } *tsip = *sip; tsip->si_pname = tpname; (void) strcpy(tsip->si_pname, sip->si_pname); } mutex_exit(&swapinfo_lock); if (sip) { error = ENOMEM; goto lout; } ust = (swapent_t *)((swaptbl_t *)sc_arg)->swt_ent; for (tsip = csip, cnt = 0; cnt < nswap; tsip++, ust++, cnt++) { if (copyin(ust, &st, sizeof (swapent_t)) != 0) { error = EFAULT; goto lout; } st.ste_flags = tsip->si_flags; st.ste_length = (tsip->si_eoff - tsip->si_soff) >> SCTRSHFT; st.ste_start = tsip->si_soff >> SCTRSHFT; st.ste_pages = tsip->si_npgs; st.ste_free = tsip->si_nfpgs; if (copyout(&st, ust, sizeof (swapent_t)) != 0) { error = EFAULT; goto lout; } if (!tsip->si_pnamelen) continue; if (copyout(tsip->si_pname, st.ste_path, tsip->si_pnamelen) != 0) { error = EFAULT; goto lout; } } *rv = nswap; lout: kmem_free(csip, tmp_nswapfiles * sizeof (struct swapinfo)); kmem_free(pname, nlen); return (error); case SC_ADD: case SC_REMOVE: break; default: return (EINVAL); } if ((error = secpolicy_swapctl(CRED())) != 0) return (error); if (copyin(sc_arg, &sr, sizeof (swapres_t))) return (EFAULT); /* Allocate the space to read in pathname */ if ((swapname = kmem_alloc(MAXPATHLEN, KM_NOSLEEP)) == NULL) return (ENOMEM); error = copyinstr(sr.sr_name, swapname, MAXPATHLEN, 0); if (error) goto out; error = lookupname(swapname, UIO_SYSSPACE, FOLLOW, NULLVPP, &vp); if (error) { if (sc_cmd == SC_ADD) goto out; /* see if we match by name */ vp = swapdel_byname(swapname, (size_t)sr.sr_start); if (vp == NULL) goto out; } if (vp->v_flag & (VNOMAP | VNOSWAP)) { VN_RELE(vp); error = ENOSYS; goto out; } switch (vp->v_type) { case VBLK: break; case VREG: if (vp->v_vfsp && vn_is_readonly(vp)) error = EROFS; else error = VOP_ACCESS(vp, VREAD|VWRITE, 0, CRED(), NULL); break; case VDIR: error = EISDIR; break; default: error = ENOSYS; break; } if (error == 0) { if (sc_cmd == SC_REMOVE) error = swapdel(vp, sr.sr_start); else error = swapadd(vp, sr.sr_start, sr.sr_length, swapname); } VN_RELE(vp); out: kmem_free(swapname, MAXPATHLEN); return (error); } #if defined(_LP64) && defined(_SYSCALL32) int swapctl32(int sc_cmd, void *sc_arg, int *rv) { struct swapinfo *sip, *csip, *tsip; int error = 0; struct swapent32 st, *ust; struct swapres32 sr; struct vnode *vp; int cnt = 0; int tmp_nswapfiles; int nswap; int length, nlen; int gplen = 0, plen; char *swapname; char *pname; char *tpname; struct anoninfo32 ai; size_t s; spgcnt_t avail; int global = INGLOBALZONE(curproc); struct zone *zp = curproc->p_zone; /* * When running in a zone we want to hide the details of the swap * devices: we report there only being one swap device named "swap" * having a size equal to the sum of the sizes of all real swap devices * on the system. */ switch (sc_cmd) { case SC_GETNSWP: if (global) *rv = nswapfiles; else *rv = 1; return (0); case SC_AINFO: /* * Return anoninfo information with these changes: * ani_max = maximum amount of swap space * (including potentially available physical memory) * ani_free = amount of unallocated anonymous memory * (some of which might be reserved and including * potentially available physical memory) * ani_resv = amount of claimed (reserved) anonymous memory */ avail = MAX((spgcnt_t)(availrmem - swapfs_minfree), 0); s = (k_anoninfo.ani_max + k_anoninfo.ani_mem_resv) + avail; if (s > UINT32_MAX) return (EOVERFLOW); ai.ani_max = s; /* Update ani_free */ set_anoninfo(); s = k_anoninfo.ani_free + avail; if (s > UINT32_MAX) return (EOVERFLOW); ai.ani_free = s; s = k_anoninfo.ani_phys_resv + k_anoninfo.ani_mem_resv; if (s > UINT32_MAX) return (EOVERFLOW); ai.ani_resv = s; if (!global && zp->zone_max_swap_ctl != UINT64_MAX) { /* * We're in a non-global zone with a swap cap. We * always report the system-wide values for the global * zone, even though it too can have a swap cap. * See the comment for the SC_AINFO case in swapctl() * which explains the following logic. */ rctl_qty_t cap, used; pgcnt_t pgcap, sys_avail; mutex_enter(&zp->zone_mem_lock); cap = zp->zone_max_swap_ctl; used = zp->zone_max_swap; mutex_exit(&zp->zone_mem_lock); pgcap = MIN(btop(cap), ai.ani_max); ai.ani_free = pgcap - btop(used); /* Get the system-wide swap currently available. */ sys_avail = ai.ani_max - ai.ani_resv; if (sys_avail < ai.ani_free) ai.ani_resv = pgcap - sys_avail; else ai.ani_resv = btop(used); ai.ani_max = pgcap; } if (copyout(&ai, sc_arg, sizeof (ai)) != 0) return (EFAULT); return (0); case SC_LIST: if (copyin(sc_arg, &length, sizeof (int32_t)) != 0) return (EFAULT); if (!global) { struct swapent32 st; char *swappath = "swap"; if (length < 1) return (ENOMEM); ust = (swapent32_t *)((swaptbl32_t *)sc_arg)->swt_ent; if (copyin(ust, &st, sizeof (swapent32_t)) != 0) return (EFAULT); st.ste_start = PAGESIZE >> SCTRSHFT; st.ste_length = (off_t)0; st.ste_pages = 0; st.ste_free = 0; st.ste_flags = 0; mutex_enter(&swapinfo_lock); for (sip = swapinfo, nswap = 0; sip != NULL && nswap < nswapfiles; sip = sip->si_next, nswap++) { st.ste_length += (sip->si_eoff - sip->si_soff) >> SCTRSHFT; st.ste_pages += sip->si_npgs; st.ste_free += sip->si_nfpgs; } mutex_exit(&swapinfo_lock); if (zp->zone_max_swap_ctl != UINT64_MAX) { rctl_qty_t cap, used; mutex_enter(&zp->zone_mem_lock); cap = zp->zone_max_swap_ctl; used = zp->zone_max_swap; mutex_exit(&zp->zone_mem_lock); st.ste_length = MIN(cap, st.ste_length); st.ste_pages = MIN(btop(cap), st.ste_pages); st.ste_free = MIN(st.ste_pages - btop(used), st.ste_free); } if (copyout(&st, ust, sizeof (swapent32_t)) != 0 || copyout(swappath, (caddr_t)(uintptr_t)st.ste_path, strlen(swappath) + 1) != 0) { return (EFAULT); } *rv = 1; return (0); } beginning: mutex_enter(&swapinfo_lock); tmp_nswapfiles = nswapfiles; mutex_exit(&swapinfo_lock); /* * Return early if there are no swap entries to report: */ if (tmp_nswapfiles < 1) { *rv = 0; return (0); } /* Return an error if not enough space for the whole table. */ if (length < tmp_nswapfiles) return (ENOMEM); /* * Get memory to hold the swap entries and their names. We'll * copy the real entries into these and then copy these out. * Allocating the pathname memory is only a guess so we may * find that we need more and have to do it again. * All this is because we have to hold the anon lock while * traversing the swapinfo list, and we can't be doing copyouts * and/or kmem_alloc()s during this. */ csip = kmem_zalloc(tmp_nswapfiles * sizeof (*csip), KM_SLEEP); retry: nlen = tmp_nswapfiles * (gplen += 100); pname = kmem_zalloc(nlen, KM_SLEEP); mutex_enter(&swapinfo_lock); if (tmp_nswapfiles != nswapfiles) { mutex_exit(&swapinfo_lock); kmem_free(pname, nlen); kmem_free(csip, tmp_nswapfiles * sizeof (*csip)); gplen = 0; goto beginning; } for (sip = swapinfo, tsip = csip, tpname = pname, nswap = 0; (sip != NULL) && (nswap < tmp_nswapfiles); sip = sip->si_next, tsip++, tpname += plen, nswap++) { plen = sip->si_pnamelen; if (tpname + plen - pname > nlen) { mutex_exit(&swapinfo_lock); kmem_free(pname, nlen); goto retry; } *tsip = *sip; tsip->si_pname = tpname; (void) strcpy(tsip->si_pname, sip->si_pname); } mutex_exit(&swapinfo_lock); if (sip != NULL) { error = ENOMEM; goto lout; } ust = (swapent32_t *)((swaptbl32_t *)sc_arg)->swt_ent; for (tsip = csip, cnt = 0; cnt < nswap; tsip++, ust++, cnt++) { if (copyin(ust, &st, sizeof (*ust)) != 0) { error = EFAULT; goto lout; } st.ste_flags = tsip->si_flags; st.ste_length = (tsip->si_eoff - tsip->si_soff) >> SCTRSHFT; st.ste_start = tsip->si_soff >> SCTRSHFT; st.ste_pages = tsip->si_npgs; st.ste_free = tsip->si_nfpgs; if (copyout(&st, ust, sizeof (st)) != 0) { error = EFAULT; goto lout; } if (!tsip->si_pnamelen) continue; if (copyout(tsip->si_pname, (caddr_t)(uintptr_t)st.ste_path, tsip->si_pnamelen) != 0) { error = EFAULT; goto lout; } } *rv = nswap; lout: kmem_free(csip, tmp_nswapfiles * sizeof (*csip)); kmem_free(pname, nlen); return (error); case SC_ADD: case SC_REMOVE: break; default: return (EINVAL); } if ((error = secpolicy_swapctl(CRED())) != 0) return (error); if (copyin(sc_arg, &sr, sizeof (sr))) return (EFAULT); /* Allocate the space to read in pathname */ if ((swapname = kmem_alloc(MAXPATHLEN, KM_NOSLEEP)) == NULL) return (ENOMEM); error = copyinstr((caddr_t)(uintptr_t)sr.sr_name, swapname, MAXPATHLEN, NULL); if (error) goto out; error = lookupname(swapname, UIO_SYSSPACE, FOLLOW, NULLVPP, &vp); if (error) { if (sc_cmd == SC_ADD) goto out; /* see if we match by name */ vp = swapdel_byname(swapname, (uint_t)sr.sr_start); if (vp == NULL) goto out; } if (vp->v_flag & (VNOMAP | VNOSWAP)) { VN_RELE(vp); error = ENOSYS; goto out; } switch (vp->v_type) { case VBLK: break; case VREG: if (vp->v_vfsp && vn_is_readonly(vp)) error = EROFS; else error = VOP_ACCESS(vp, VREAD|VWRITE, 0, CRED(), NULL); break; case VDIR: error = EISDIR; break; default: error = ENOSYS; break; } if (error == 0) { if (sc_cmd == SC_REMOVE) error = swapdel(vp, sr.sr_start); else error = swapadd(vp, sr.sr_start, sr.sr_length, swapname); } VN_RELE(vp); out: kmem_free(swapname, MAXPATHLEN); return (error); } #endif /* _LP64 && _SYSCALL32 */ /* * Add a new swap file. */ int swapadd(struct vnode *vp, ulong_t lowblk, ulong_t nblks, char *swapname) { struct swapinfo **sipp, *nsip = NULL, *esip = NULL; struct vnode *cvp; struct vattr vattr; pgcnt_t pages; u_offset_t soff, eoff; int error; ssize_t i, start, end; ushort_t wasswap; ulong_t startblk; size_t returned_mem; SWAP_PRINT(SW_CTL, "swapadd: vp %p lowblk %ld nblks %ld swapname %s\n", vp, lowblk, nblks, swapname, 0); /* * Get the real vnode. (If vp is not a specnode it just returns vp, so * it does the right thing, but having this code know about specnodes * violates the spirit of having it be indepedent of vnode type.) */ cvp = common_specvp(vp); /* * Or in VISSWAP so file system has chance to deny swap-ons during open. */ mutex_enter(&cvp->v_lock); wasswap = cvp->v_flag & VISSWAP; cvp->v_flag |= VISSWAP; mutex_exit(&cvp->v_lock); mutex_enter(&swap_lock); if (error = VOP_OPEN(&cvp, FREAD|FWRITE, CRED(), NULL)) { mutex_exit(&swap_lock); /* restore state of v_flag */ if (!wasswap) { mutex_enter(&cvp->v_lock); cvp->v_flag &= ~VISSWAP; mutex_exit(&cvp->v_lock); } return (error); } mutex_exit(&swap_lock); /* * Get partition size. Return error if empty partition, * or if request does not fit within the partition. * If this is the first swap device, we can reduce * the size of the swap area to match what is * available. This can happen if the system was built * on a machine with a different size swap partition. */ vattr.va_mask = AT_SIZE; if (error = VOP_GETATTR(cvp, &vattr, ATTR_COMM, CRED(), NULL)) goto out; /* * Specfs returns a va_size of MAXOFFSET_T (UNKNOWN_SIZE) when the * size of the device can't be determined. */ if ((vattr.va_size == 0) || (vattr.va_size == MAXOFFSET_T)) { error = EINVAL; goto out; } #ifdef _ILP32 /* * No support for large swap in 32-bit OS, if the size of the swap is * bigger than MAXOFF32_T then the size used by swapfs must be limited. * This limitation is imposed by the swap subsystem itself, a D_64BIT * driver as the target of swap operation should be able to field * the IO. */ if (vattr.va_size > MAXOFF32_T) { cmn_err(CE_NOTE, "!swap device %s truncated from 0x%llx to 0x%x bytes", swapname, vattr.va_size, MAXOFF32_T); vattr.va_size = MAXOFF32_T; } #endif /* _ILP32 */ /* Fail if file not writeable (try to set size to current size) */ vattr.va_mask = AT_SIZE; if (error = VOP_SETATTR(cvp, &vattr, 0, CRED(), NULL)) goto out; /* Fail if fs does not support VOP_PAGEIO */ error = VOP_PAGEIO(cvp, (page_t *)NULL, (u_offset_t)0, 0, 0, CRED(), NULL); if (error == ENOSYS) goto out; else error = 0; /* * If swapping on the root filesystem don't put swap blocks that * correspond to the miniroot filesystem on the swap free list. */ if (cvp == rootdir) startblk = roundup(MINIROOTSIZE<>SCTRSHFT; else /* Skip 1st page (disk label) */ startblk = (ulong_t)(lowblk ? lowblk : 1); soff = startblk << SCTRSHFT; if (soff >= vattr.va_size) { error = EINVAL; goto out; } /* * If user specified 0 blks, use the size of the device */ eoff = nblks ? soff + (nblks - (startblk - lowblk) << SCTRSHFT) : vattr.va_size; SWAP_PRINT(SW_CTL, "swapadd: va_size %ld soff %ld eoff %ld\n", vattr.va_size, soff, eoff, 0, 0); if (eoff > vattr.va_size) { error = EINVAL; goto out; } /* * The starting and ending offsets must be page aligned. * Round soff up to next page boundary, round eoff * down to previous page boundary. */ soff = ptob(btopr(soff)); eoff = ptob(btop(eoff)); if (soff >= eoff) { SWAP_PRINT(SW_CTL, "swapadd: soff %ld >= eoff %ld\n", soff, eoff, 0, 0, 0); error = EINVAL; goto out; } pages = btop(eoff - soff); /* Allocate and partially set up the new swapinfo */ nsip = kmem_zalloc(sizeof (struct swapinfo), KM_SLEEP); nsip->si_vp = cvp; nsip->si_soff = soff; nsip->si_eoff = eoff; nsip->si_hint = 0; nsip->si_checkcnt = nsip->si_alloccnt = 0; nsip->si_pnamelen = (int)strlen(swapname) + 1; nsip->si_pname = (char *)kmem_zalloc(nsip->si_pnamelen, KM_SLEEP); bcopy(swapname, nsip->si_pname, nsip->si_pnamelen - 1); SWAP_PRINT(SW_CTL, "swapadd: allocating swapinfo for %s, %ld pages\n", swapname, pages, 0, 0, 0); /* * Size of swapslots map in bytes */ nsip->si_mapsize = P2ROUNDUP(pages, NBBW) / NBBY; nsip->si_swapslots = kmem_zalloc(nsip->si_mapsize, KM_SLEEP); /* * Permanently set the bits that can't ever be allocated, * i.e. those from the ending offset to the round up slot for the * swapslots bit map. */ start = pages; end = P2ROUNDUP(pages, NBBW); for (i = start; i < end; i++) { SWAP_PRINT(SW_CTL, "swapadd: set bit for page %ld\n", i, 0, 0, 0, 0); SETBIT(nsip->si_swapslots, i); } nsip->si_npgs = nsip->si_nfpgs = pages; /* * Now check to see if we can add it. We wait til now to check because * we need the swapinfo_lock and we don't want sleep with it (e.g., * during kmem_alloc()) while we're setting up the swapinfo. */ mutex_enter(&swapinfo_lock); for (sipp = &swapinfo; (esip = *sipp) != NULL; sipp = &esip->si_next) { if (esip->si_vp == cvp) { if (esip->si_soff == soff && esip->si_npgs == pages && (esip->si_flags & ST_DOINGDEL)) { /* * We are adding a device that we are in the * middle of deleting. Just clear the * ST_DOINGDEL flag to signal this and * the deletion routine will eventually notice * it and add it back. */ esip->si_flags &= ~ST_DOINGDEL; mutex_exit(&swapinfo_lock); goto out; } /* disallow overlapping swap files */ if ((soff < esip->si_eoff) && (eoff > esip->si_soff)) { error = EEXIST; mutex_exit(&swapinfo_lock); goto out; } } } nswapfiles++; /* * add new swap device to list and shift allocations to it * before updating the anoninfo counters */ *sipp = nsip; silast = nsip; /* * Update the total amount of reservable swap space * accounting properly for swap space from physical memory */ /* New swap device soaks up currently reserved memory swap */ mutex_enter(&anoninfo_lock); ASSERT(k_anoninfo.ani_mem_resv >= k_anoninfo.ani_locked_swap); ASSERT(k_anoninfo.ani_max >= k_anoninfo.ani_phys_resv); k_anoninfo.ani_max += pages; ANI_ADD(pages); if (k_anoninfo.ani_mem_resv > k_anoninfo.ani_locked_swap) { returned_mem = MIN(k_anoninfo.ani_mem_resv - k_anoninfo.ani_locked_swap, k_anoninfo.ani_max - k_anoninfo.ani_phys_resv); ANI_ADD(-returned_mem); k_anoninfo.ani_free -= returned_mem; k_anoninfo.ani_mem_resv -= returned_mem; k_anoninfo.ani_phys_resv += returned_mem; mutex_enter(&freemem_lock); availrmem += returned_mem; mutex_exit(&freemem_lock); } /* * At boot time, to permit booting small memory machines using * only physical memory as swap space, we allowed a dangerously * large amount of memory to be used as swap space; now that * more physical backing store is available bump down the amount * we can get from memory to a safer size. */ if (swapfs_minfree < swapfs_desfree) { mutex_enter(&freemem_lock); if (availrmem > swapfs_desfree || !k_anoninfo.ani_mem_resv) swapfs_minfree = swapfs_desfree; mutex_exit(&freemem_lock); } SWAP_PRINT(SW_CTL, "swapadd: ani_max %ld ani_free %ld\n", k_anoninfo.ani_free, k_anoninfo.ani_free, 0, 0, 0); mutex_exit(&anoninfo_lock); mutex_exit(&swapinfo_lock); /* Initialize the dump device */ mutex_enter(&dump_lock); if (dumpvp == NULL) (void) dumpinit(vp, swapname, 0); mutex_exit(&dump_lock); VN_HOLD(cvp); out: if (error || esip) { SWAP_PRINT(SW_CTL, "swapadd: error (%d)\n", error, 0, 0, 0, 0); if (!wasswap) { mutex_enter(&cvp->v_lock); cvp->v_flag &= ~VISSWAP; mutex_exit(&cvp->v_lock); } if (nsip) { kmem_free(nsip->si_swapslots, (size_t)nsip->si_mapsize); kmem_free(nsip->si_pname, nsip->si_pnamelen); kmem_free(nsip, sizeof (*nsip)); } mutex_enter(&swap_lock); (void) VOP_CLOSE(cvp, FREAD|FWRITE, 1, (offset_t)0, CRED(), NULL); mutex_exit(&swap_lock); } return (error); } /* * Delete a swap file. */ static int swapdel( struct vnode *vp, ulong_t lowblk) /* Low block number of area to delete. */ { struct swapinfo **sipp, *osip = NULL; struct vnode *cvp; u_offset_t soff; int error = 0; u_offset_t toff = 0; struct vnode *tvp = NULL; spgcnt_t pages; struct anon **app, *ap; kmutex_t *ahm; pgcnt_t adjust_swap = 0; /* Find the swap file entry for the file to be deleted */ cvp = common_specvp(vp); lowblk = lowblk ? lowblk : 1; /* Skip first page (disk label) */ soff = ptob(btopr(lowblk << SCTRSHFT)); /* must be page aligned */ mutex_enter(&swapinfo_lock); for (sipp = &swapinfo; (osip = *sipp) != NULL; sipp = &osip->si_next) { if ((osip->si_vp == cvp) && (osip->si_soff == soff) && (osip->si_flags == 0)) break; } /* If the file was not found, error. */ if (osip == NULL) { error = EINVAL; mutex_exit(&swapinfo_lock); goto out; } pages = osip->si_npgs; /* * Do not delete if we will be low on swap pages. */ mutex_enter(&anoninfo_lock); ASSERT(k_anoninfo.ani_mem_resv >= k_anoninfo.ani_locked_swap); ASSERT(k_anoninfo.ani_max >= k_anoninfo.ani_phys_resv); mutex_enter(&freemem_lock); if (((k_anoninfo.ani_max - k_anoninfo.ani_phys_resv) + MAX((spgcnt_t)(availrmem - swapfs_minfree), 0)) < pages) { mutex_exit(&freemem_lock); mutex_exit(&anoninfo_lock); error = ENOMEM; cmn_err(CE_WARN, "swapdel - too few free pages"); mutex_exit(&swapinfo_lock); goto out; } mutex_exit(&freemem_lock); k_anoninfo.ani_max -= pages; /* If needed, reserve memory swap to replace old device */ if (k_anoninfo.ani_phys_resv > k_anoninfo.ani_max) { adjust_swap = k_anoninfo.ani_phys_resv - k_anoninfo.ani_max; k_anoninfo.ani_phys_resv -= adjust_swap; k_anoninfo.ani_mem_resv += adjust_swap; mutex_enter(&freemem_lock); availrmem -= adjust_swap; mutex_exit(&freemem_lock); ANI_ADD(adjust_swap); } ASSERT(k_anoninfo.ani_mem_resv >= k_anoninfo.ani_locked_swap); ASSERT(k_anoninfo.ani_max >= k_anoninfo.ani_phys_resv); mutex_exit(&anoninfo_lock); ANI_ADD(-pages); /* * Set the delete flag. This prevents anyone from allocating more * pages from this file. Also set ST_DOINGDEL. Someone who wants to * add the file back while we're deleting it will signify by clearing * this flag. */ osip->si_flags |= ST_INDEL|ST_DOINGDEL; mutex_exit(&swapinfo_lock); /* * Free all the allocated physical slots for this file. We do this * by walking through the entire anon hash array, because we need * to update all the anon slots that have physical swap slots on * this file, and this is the only way to find them all. We go back * to the beginning of a bucket after each slot is freed because the * anonhash_lock is not held during the free and thus the hash table * may change under us. */ for (app = anon_hash; app < &anon_hash[ANON_HASH_SIZE]; app++) { ahm = &anonhash_lock[(app - anon_hash) & (AH_LOCK_SIZE - 1)].pad_mutex; mutex_enter(ahm); top: for (ap = *app; ap != NULL; ap = ap->an_hash) { if (ap->an_pvp == cvp && ap->an_poff >= osip->si_soff && ap->an_poff < osip->si_eoff) { ASSERT(TESTBIT(osip->si_swapslots, btop((size_t)(ap->an_poff - osip->si_soff)))); tvp = ap->an_vp; toff = ap->an_off; VN_HOLD(tvp); mutex_exit(ahm); error = swapslot_free(tvp, toff, osip); VN_RELE(tvp); mutex_enter(ahm); if (!error && (osip->si_flags & ST_DOINGDEL)) { goto top; } else { if (error) { cmn_err(CE_WARN, "swapslot_free failed %d", error); } /* * Add device back before making it * visible. */ mutex_enter(&swapinfo_lock); osip->si_flags &= ~(ST_INDEL | ST_DOINGDEL); mutex_exit(&swapinfo_lock); /* * Update the anon space available */ mutex_enter(&anoninfo_lock); k_anoninfo.ani_phys_resv += adjust_swap; k_anoninfo.ani_mem_resv -= adjust_swap; k_anoninfo.ani_max += pages; mutex_enter(&freemem_lock); availrmem += adjust_swap; mutex_exit(&freemem_lock); mutex_exit(&anoninfo_lock); ANI_ADD(pages); mutex_exit(ahm); goto out; } } } mutex_exit(ahm); } /* All done, they'd better all be free! */ mutex_enter(&swapinfo_lock); ASSERT(osip->si_nfpgs == osip->si_npgs); /* Now remove it from the swapinfo list */ for (sipp = &swapinfo; *sipp != NULL; sipp = &(*sipp)->si_next) { if (*sipp == osip) break; } ASSERT(*sipp); *sipp = osip->si_next; if (silast == osip) if ((silast = osip->si_next) == NULL) silast = swapinfo; nswapfiles--; mutex_exit(&swapinfo_lock); kmem_free(osip->si_swapslots, osip->si_mapsize); kmem_free(osip->si_pname, osip->si_pnamelen); kmem_free(osip, sizeof (*osip)); mutex_enter(&dump_lock); if (cvp == dumpvp) dumpfini(); mutex_exit(&dump_lock); /* Release the vnode */ mutex_enter(&swap_lock); (void) VOP_CLOSE(cvp, FREAD|FWRITE, 1, (offset_t)0, CRED(), NULL); mutex_enter(&cvp->v_lock); cvp->v_flag &= ~VISSWAP; mutex_exit(&cvp->v_lock); VN_RELE(cvp); mutex_exit(&swap_lock); out: return (error); } /* * Free up a physical swap slot on swapinfo sip, currently in use by the * anonymous page whose name is (vp, off). */ static int swapslot_free( struct vnode *vp, u_offset_t off, struct swapinfo *sip) { struct page *pp = NULL; struct anon *ap = NULL; int error = 0; kmutex_t *ahm; struct vnode *pvp = NULL; u_offset_t poff; int alloc_pg = 0; ASSERT(sip->si_vp != NULL); /* * Get the page for the old swap slot if exists or create a new one. */ again: if ((pp = page_lookup(vp, off, SE_SHARED)) == NULL) { pp = page_create_va(vp, off, PAGESIZE, PG_WAIT | PG_EXCL, segkmap, NULL); if (pp == NULL) goto again; alloc_pg = 1; error = swap_getphysname(vp, off, &pvp, &poff); if (error || pvp != sip->si_vp || poff < sip->si_soff || poff >= sip->si_eoff) { page_io_unlock(pp); /*LINTED: constant in conditional context*/ VN_DISPOSE(pp, B_INVAL, 0, kcred); return (0); } error = VOP_PAGEIO(pvp, pp, poff, PAGESIZE, B_READ, CRED(), NULL); if (error) { page_io_unlock(pp); if (error == EFAULT) error = 0; /*LINTED: constant in conditional context*/ VN_DISPOSE(pp, B_INVAL, 0, kcred); return (error); } } /* * The anon could have been removed by anon_decref* and/or reallocated * by anon layer (an_pvp == NULL) with the same vp, off. * In this case the page which has been allocated needs to * be freed. */ if (!alloc_pg) page_io_lock(pp); ahm = AH_MUTEX(vp, off); mutex_enter(ahm); ap = swap_anon(vp, off); if ((ap == NULL || ap->an_pvp == NULL) && alloc_pg) { mutex_exit(ahm); page_io_unlock(pp); /*LINTED: constant in conditional context*/ VN_DISPOSE(pp, B_INVAL, 0, kcred); return (0); } /* * Free the physical slot. It may have been freed up and replaced with * another one while we were getting the page so we have to re-verify * that this is really one we want. If we do free the slot we have * to mark the page modified, as its backing store is now gone. */ if ((ap != NULL) && (ap->an_pvp == sip->si_vp && ap->an_poff >= sip->si_soff && ap->an_poff < sip->si_eoff)) { swap_phys_free(ap->an_pvp, ap->an_poff, PAGESIZE); ap->an_pvp = NULL; ap->an_poff = 0; mutex_exit(ahm); hat_setmod(pp); } else { mutex_exit(ahm); } page_io_unlock(pp); page_unlock(pp); return (0); } /* * Get contig physical backing store for vp, in the range * [*offp, *offp + *lenp), May back a subrange of this, but must * always include the requested offset or fail. Returns the offsets * backed as [*offp, *offp + *lenp) and the physical offsets used to * back them from *pvpp in the range [*pstartp, *pstartp + *lenp). * Returns 0 for success * SE_NOANON -- no anon slot for requested paged * SE_NOSWAP -- no physical swap space available */ int swap_newphysname( struct vnode *vp, u_offset_t offset, u_offset_t *offp, size_t *lenp, struct vnode **pvpp, u_offset_t *poffp) { struct anon *ap = NULL; /* anon slot for vp, off */ int error = 0; struct vnode *pvp; u_offset_t poff, pstart, prem; size_t plen; u_offset_t off, start; kmutex_t *ahm; ASSERT(*offp <= offset && offset < *offp + *lenp); /* Get new physical swap slots. */ plen = *lenp; if (!swap_phys_alloc(&pvp, &pstart, &plen, 0)) { /* * No swap available so return error unless requested * offset is already backed in which case return that. */ ahm = AH_MUTEX(vp, offset); mutex_enter(ahm); if ((ap = swap_anon(vp, offset)) == NULL) { error = SE_NOANON; mutex_exit(ahm); return (error); } error = (ap->an_pvp ? 0 : SE_NOSWAP); *offp = offset; *lenp = PAGESIZE; *pvpp = ap->an_pvp; *poffp = ap->an_poff; mutex_exit(ahm); return (error); } /* * We got plen (<= *lenp) contig slots. Use these to back a * subrange of [*offp, *offp + *lenp) which includes offset. * For now we just put offset at the end of the kluster. * Clearly there are other possible choices - which is best? */ start = MAX(*offp, (offset + PAGESIZE > plen) ? (offset + PAGESIZE - plen) : 0); ASSERT(start + plen <= *offp + *lenp); for (off = start, poff = pstart; poff < pstart + plen; off += PAGESIZE, poff += PAGESIZE) { ahm = AH_MUTEX(vp, off); mutex_enter(ahm); if ((ap = swap_anon(vp, off)) != NULL) { /* Free old slot if any, and assign new one */ if (ap->an_pvp) swap_phys_free(ap->an_pvp, ap->an_poff, PAGESIZE); ap->an_pvp = pvp; ap->an_poff = poff; } else { /* No anon slot for a klustered page, quit. */ prem = (pstart + plen) - poff; /* Already did requested page, do partial kluster */ if (off > offset) { plen = poff - pstart; error = 0; /* Fail on requested page, error */ } else if (off == offset) { error = SE_NOANON; /* Fail on prior page, fail on requested page, error */ } else if ((ap = swap_anon(vp, offset)) == NULL) { error = SE_NOANON; /* Fail on prior page, got requested page, do only it */ } else { /* Free old slot if any, and assign new one */ if (ap->an_pvp) swap_phys_free(ap->an_pvp, ap->an_poff, PAGESIZE); ap->an_pvp = pvp; ap->an_poff = poff; /* One page kluster */ start = offset; plen = PAGESIZE; pstart = poff; poff += PAGESIZE; prem -= PAGESIZE; } /* Free unassigned slots */ swap_phys_free(pvp, poff, prem); mutex_exit(ahm); break; } mutex_exit(ahm); } ASSERT(*offp <= start && start + plen <= *offp + *lenp); ASSERT(start <= offset && offset < start + plen); *offp = start; *lenp = plen; *pvpp = pvp; *poffp = pstart; return (error); } /* * Get the physical swap backing store location for a given anonymous page * named (vp, off). The backing store name is returned in (*pvpp, *poffp). * Returns 0 success * EIDRM -- no anon slot (page is not allocated) */ int swap_getphysname( struct vnode *vp, u_offset_t off, struct vnode **pvpp, u_offset_t *poffp) { struct anon *ap; int error = 0; kmutex_t *ahm; ahm = AH_MUTEX(vp, off); mutex_enter(ahm); /* Get anon slot for vp, off */ ap = swap_anon(vp, off); if (ap == NULL) { error = EIDRM; goto out; } *pvpp = ap->an_pvp; *poffp = ap->an_poff; out: mutex_exit(ahm); return (error); }