1 /***********************************************************************
2 * *
3 * This software is part of the ast package *
4 * Copyright (c) 1985-2010 AT&T Intellectual Property *
5 * and is licensed under the *
6 * Common Public License, Version 1.0 *
7 * by AT&T Intellectual Property *
8 * *
9 * A copy of the License is available at *
10 * http://www.opensource.org/licenses/cpl1.0.txt *
11 * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
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_FIOINFO
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