1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *          Copyright (c) 1985-2012 AT&T Intellectual Property          *
5 *                      and is licensed under the                       *
6 *                 Eclipse Public License, Version 1.0                  *
7 *                    by AT&T Intellectual Property                     *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *          http://www.eclipse.org/org/documents/epl-v10.html           *
11 *         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
12 *                                                                      *
13 *              Information and Software Systems Research               *
14 *                            AT&T Research                             *
15 *                           Florham Park NJ                            *
16 *                                                                      *
17 *                 Glenn Fowler <gsf@research.att.com>                  *
18 *                  David Korn <dgk@research.att.com>                   *
19 *                   Phong Vo <kpv@research.att.com>                    *
20 *                                                                      *
21 ***********************************************************************/
22 #include	"sfdchdr.h"
23 
24 /*	Discipline to turn on direct IO capability.
25 **	This currently only works for XFS on SGI's.
26 **
27 **	Written by Kiem-Phong Vo, kpv@research.att.com, 03/18/1998.
28 */
29 
30 #ifndef FDIRECT
31 #undef F_DIOINFO
32 #endif
33 
34 typedef struct _direct_s
35 {	Sfdisc_t	disc;	/* Sfio discipline	*/
36 	int		cntl;	/* file control flags	*/
37 #ifdef F_DIOINFO
38 	struct dioattr	dio;	/* direct IO params	*/
39 #endif
40 } Direct_t;
41 
42 /* convert a pointer to an int */
43 #define P2I(p)	(Sfulong_t)((char*)(p) - (char*)0)
44 
45 #if __STD_C
diordwr(Sfio_t * f,Void_t * buf,size_t n,Direct_t * di,int type)46 static ssize_t diordwr(Sfio_t* f, Void_t* buf, size_t n, Direct_t* di, int type)
47 #else
48 static ssize_t diordwr(f, buf, n, di, type)
49 Sfio_t*		f;
50 Void_t*		buf;
51 size_t		n;
52 Direct_t*	di;
53 int		type;
54 #endif
55 {
56 	size_t	rw, done;
57 	ssize_t	rv;
58 
59 	done = 0;	/* amount processed by direct IO */
60 	rv = 0;
61 
62 #ifdef F_DIOINFO
63 	if((P2I(buf)%di->dio.d_mem) == 0 &&
64 	   (f->here%di->dio.d_miniosz) == 0 && n >= di->dio.d_miniosz )
65 	{	/* direct IO ok, make sure we're in the right mode */
66 		if(!(di->cntl & FDIRECT) )
67 		{	di->cntl |= FDIRECT;
68 			(void)fcntl(f->file, F_SETFL, di->cntl);
69 		}
70 
71 		for(rw = (n/di->dio.d_miniosz)*di->dio.d_miniosz;; )
72 		{	size_t	io;
73 
74 			if((io = rw) > di->dio.d_maxiosz )
75 				io = di->dio.d_maxiosz;
76 			if(type == SF_READ)
77 				rv = read(f->file,buf,io);
78 			else	rv = write(f->file,buf,io);
79 
80 			if(rv > 0)
81 			{	rw -= rv; done += rv;
82 				buf = (Void_t*)((char*)buf + rv);
83 			}
84 
85 			if(rv < io || rw < di->dio.d_miniosz)
86 				break;
87 		}
88 	}
89 
90 	if(done < n && (di->cntl & FDIRECT) )
91 	{	/* turn off directIO for remaining IO operation */
92 		di->cntl &= ~FDIRECT;
93 		(void)fcntl(f->file, F_SETFL, di->cntl);
94 	}
95 #endif /*F_DIOINFO*/
96 
97 	if((rw = n-done) > 0 &&
98 	   (rv = type == SF_READ ? read(f->file,buf,rw) : write(f->file,buf,rw)) > 0 )
99 		done += rv;
100 
101 	return done ? done : rv;
102 }
103 
104 #if __STD_C
dioread(Sfio_t * f,Void_t * buf,size_t n,Sfdisc_t * disc)105 static ssize_t dioread(Sfio_t* f, Void_t* buf, size_t n, Sfdisc_t* disc)
106 #else
107 static ssize_t dioread(f, buf, n, disc)
108 Sfio_t*		f;
109 Void_t*		buf;
110 size_t		n;
111 Sfdisc_t*	disc;
112 #endif
113 {
114 	return diordwr(f, buf, n, (Direct_t*)disc, SF_READ);
115 }
116 
117 #if __STD_C
diowrite(Sfio_t * f,const Void_t * buf,size_t n,Sfdisc_t * disc)118 static ssize_t diowrite(Sfio_t* f, const Void_t* buf, size_t n, Sfdisc_t* disc)
119 #else
120 static ssize_t diowrite(f, buf, n, disc)
121 Sfio_t*		f;
122 Void_t*		buf;
123 size_t		n;
124 Sfdisc_t*	disc;
125 #endif
126 {
127 	return diordwr(f, (Void_t*)buf, n, (Direct_t*)disc, SF_WRITE);
128 }
129 
130 #if __STD_C
dioexcept(Sfio_t * f,int type,Void_t * data,Sfdisc_t * disc)131 static int dioexcept(Sfio_t* f, int type, Void_t* data, Sfdisc_t* disc)
132 #else
133 static int dioexcept(f,type,data,disc)
134 Sfio_t*		f;
135 int		type;
136 Void_t*		data;
137 Sfdisc_t*	disc;
138 #endif
139 {
140 	Direct_t*	di = (Direct_t*)disc;
141 
142 	if(type == SF_FINAL || type == SF_DPOP)
143 	{
144 #ifdef F_DIOINFO
145 		if(di->cntl&FDIRECT)
146 		{	di->cntl &= ~FDIRECT;
147 			(void)fcntl(f->file,F_SETFL,di->cntl);
148 		}
149 #endif
150 		free(disc);
151 	}
152 
153 	return 0;
154 }
155 
156 #if __STD_C
sfdcdio(Sfio_t * f,size_t bufsize)157 int sfdcdio(Sfio_t* f, size_t bufsize)
158 #else
159 int sfdcdio(f, bufsize)
160 Sfio_t*	f;
161 size_t	bufsize;
162 #endif
163 {
164 #ifndef F_DIOINFO
165 	return -1;
166 #else
167 	int		cntl;
168 	struct dioattr	dio;
169 	Void_t*		buf;
170 	Direct_t*	di;
171 
172 	if(f->extent < 0 || (f->flags&SF_STRING))
173 		return -1;
174 
175 	if((cntl = fcntl(f->file,F_GETFL,0)) < 0)
176 		return -1;
177 
178 	if(!(cntl&FDIRECT) )
179 	{	cntl |= FDIRECT;
180 		if(fcntl(f->file,F_SETFL,cntl) < 0)
181 			return -1;
182 	}
183 
184 	if(fcntl(f->file,F_DIOINFO,&dio) < 0)
185 		goto no_direct;
186 
187 	if(bufsize > 0)
188 		bufsize = (bufsize/dio.d_miniosz)*dio.d_miniosz;
189 	if(bufsize <= 0)
190 		bufsize = dio.d_miniosz*64;
191 	if(bufsize > dio.d_maxiosz)
192 		bufsize = dio.d_maxiosz;
193 
194 	if(!(di = (Direct_t*)malloc(sizeof(Direct_t))) )
195 		goto no_direct;
196 
197 	if(!(buf = (Void_t*)memalign(dio.d_mem,bufsize)) )
198 	{	free(di);
199 		goto no_direct;
200 	}
201 
202 	sfsetbuf(f,buf,bufsize);
203 	if(sfsetbuf(f,buf,0) == buf)
204 		sfset(f,SF_MALLOC,1);
205 	else
206 	{	free(buf);
207 		free(di);
208 		goto no_direct;
209 	}
210 
211 	di->disc.readf = dioread;
212 	di->disc.writef = diowrite;
213 	di->disc.seekf = NIL(Sfseek_f);
214 	di->disc.exceptf = dioexcept;
215 	di->cntl = cntl;
216 	di->dio = dio;
217 
218 	if(sfdisc(f,(Sfdisc_t*)di) != (Sfdisc_t*)di)
219 	{	free(di);
220 	no_direct:
221 		cntl &= ~FDIRECT;
222 		(void)fcntl(f->file,F_SETFL,cntl);
223 		return -1;
224 	}
225 
226 	return 0;
227 
228 #endif /*F_DIOINFO*/
229 }
230