1 /* Linux specific extensions to fpathconf.
2 Copyright (C) 1991,95,96,98,99,2000,2001 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
19
20 /* Modified for newlib July 19, 2002 by Jeff Johnston */
21
22 #include <errno.h>
23 #include <stddef.h>
24 #include <unistd.h>
25 #include <limits.h>
26 #include <sys/stat.h>
27 #include <sys/statfs.h>
28 #include <sys/statvfs.h>
29 #include <machine/weakalias.h>
30 #include "linux_fsinfo.h"
31
32 /* The Linux kernel header mentioned this as a kind of generic value. */
33 #define LINUX_LINK_MAX 127
34
35 static long int posix_fpathconf (int fd, int name);
36
37 /* Get file-specific information about descriptor FD. */
38 long int
__fpathconf(fd,name)39 __fpathconf (fd, name)
40 int fd;
41 int name;
42 {
43 if (name == _PC_LINK_MAX)
44 {
45 struct statfs fsbuf;
46
47 /* Determine the filesystem type. */
48 if (__fstatfs (fd, &fsbuf) < 0)
49 {
50 if (errno == ENOSYS)
51 /* not possible, return the default value. */
52 return LINUX_LINK_MAX;
53
54 /* Some error occured. */
55 return -1;
56 }
57
58 switch (fsbuf.f_type)
59 {
60 case EXT2_SUPER_MAGIC:
61 return EXT2_LINK_MAX;
62
63 case MINIX_SUPER_MAGIC:
64 case MINIX_SUPER_MAGIC2:
65 return MINIX_LINK_MAX;
66
67 case MINIX2_SUPER_MAGIC:
68 case MINIX2_SUPER_MAGIC2:
69 return MINIX2_LINK_MAX;
70
71 case XENIX_SUPER_MAGIC:
72 return XENIX_LINK_MAX;
73
74 case SYSV4_SUPER_MAGIC:
75 case SYSV2_SUPER_MAGIC:
76 return SYSV_LINK_MAX;
77
78 case COH_SUPER_MAGIC:
79 return COH_LINK_MAX;
80
81 case UFS_MAGIC:
82 case UFS_CIGAM:
83 return UFS_LINK_MAX;
84
85 case REISERFS_SUPER_MAGIC:
86 return REISERFS_LINK_MAX;
87
88 default:
89 return LINUX_LINK_MAX;
90 }
91 }
92
93 return posix_fpathconf (fd, name);
94 }
95
96 /* Get file-specific information about descriptor FD. */
97 static long int
posix_fpathconf(fd,name)98 posix_fpathconf (fd, name)
99 int fd;
100 int name;
101 {
102 if (fd < 0)
103 {
104 __set_errno (EBADF);
105 return -1;
106 }
107
108 switch (name)
109 {
110 default:
111 __set_errno (EINVAL);
112 return -1;
113
114 case _PC_LINK_MAX:
115 #ifdef LINK_MAX
116 return LINK_MAX;
117 #else
118 return -1;
119 #endif
120
121 case _PC_MAX_CANON:
122 #ifdef MAX_CANON
123 return MAX_CANON;
124 #else
125 return -1;
126 #endif
127
128 case _PC_MAX_INPUT:
129 #ifdef MAX_INPUT
130 return MAX_INPUT;
131 #else
132 return -1;
133 #endif
134
135 case _PC_NAME_MAX:
136 #ifdef NAME_MAX
137 {
138 struct statfs buf;
139 int save_errno = errno;
140
141 if (__fstatfs (fd, &buf) < 0)
142 {
143 if (errno == ENOSYS)
144 {
145 __set_errno (save_errno);
146 return NAME_MAX;
147 }
148 else if (errno == ENODEV)
149 __set_errno (EINVAL);
150
151 return -1;
152 }
153 else
154 {
155 #ifdef _STATFS_F_NAMELEN
156 return buf.f_namelen;
157 #else
158 # ifdef _STATFS_F_NAME_MAX
159 return buf.f_name_max;
160 # else
161 return NAME_MAX;
162 # endif
163 #endif
164 }
165 }
166 #else
167 return -1;
168 #endif
169
170 case _PC_PATH_MAX:
171 #ifdef PATH_MAX
172 return PATH_MAX;
173 #else
174 return -1;
175 #endif
176
177 case _PC_PIPE_BUF:
178 #ifdef PIPE_BUF
179 return PIPE_BUF;
180 #else
181 return -1;
182 #endif
183
184 case _PC_CHOWN_RESTRICTED:
185 #ifdef _POSIX_CHOWN_RESTRICTED
186 return _POSIX_CHOWN_RESTRICTED;
187 #else
188 return -1;
189 #endif
190
191 case _PC_NO_TRUNC:
192 #ifdef _POSIX_NO_TRUNC
193 return _POSIX_NO_TRUNC;
194 #else
195 return -1;
196 #endif
197
198 case _PC_VDISABLE:
199 #ifdef _POSIX_VDISABLE
200 return _POSIX_VDISABLE;
201 #else
202 return -1;
203 #endif
204
205 case _PC_SYNC_IO:
206 #ifdef _POSIX_SYNC_IO
207 return _POSIX_SYNC_IO;
208 #else
209 return -1;
210 #endif
211
212 case _PC_ASYNC_IO:
213 #ifdef _POSIX_ASYNC_IO
214 {
215 /* AIO is only allowed on regular files and block devices. */
216 struct stat64 st;
217
218 if (fstat64 (fd, &st) < 0
219 || (! S_ISREG (st.st_mode) && ! S_ISBLK (st.st_mode)))
220 return -1;
221 else
222 return 1;
223 }
224 #else
225 return -1;
226 #endif
227
228 case _PC_PRIO_IO:
229 #ifdef _POSIX_PRIO_IO
230 return _POSIX_PRIO_IO;
231 #else
232 return -1;
233 #endif
234
235 case _PC_SOCK_MAXBUF:
236 #ifdef SOCK_MAXBUF
237 return SOCK_MAXBUF;
238 #else
239 return -1;
240 #endif
241
242 case _PC_FILESIZEBITS:
243 #ifdef FILESIZEBITS
244 return FILESIZEBITS;
245 #else
246 /* We let platforms with larger file sizes overwrite this value. */
247 return 32;
248 #endif
249
250 case _PC_REC_INCR_XFER_SIZE:
251 /* XXX It is not entirely clear what the limit is supposed to do.
252 What is incremented? */
253 return -1;
254
255 case _PC_REC_MAX_XFER_SIZE:
256 /* XXX It is not entirely clear what the limit is supposed to do.
257 In general there is no top limit of the number of bytes which
258 case be transported at once. */
259 return -1;
260
261 case _PC_REC_MIN_XFER_SIZE:
262 {
263 /* XXX It is not entirely clear what the limit is supposed to do.
264 I assume this is the block size of the filesystem. */
265 struct statvfs64 sv;
266
267 if (__fstatvfs64 (fd, &sv) < 0)
268 return -1;
269 return sv.f_bsize;
270 }
271
272 case _PC_REC_XFER_ALIGN:
273 {
274 /* XXX It is not entirely clear what the limit is supposed to do.
275 I assume that the number should reflect the minimal block
276 alignment. */
277 struct statvfs64 sv;
278
279 if (__fstatvfs64 (fd, &sv) < 0)
280 return -1;
281 return sv.f_frsize;
282 }
283
284 case _PC_ALLOC_SIZE_MIN:
285 {
286 /* XXX It is not entirely clear what the limit is supposed to do.
287 I assume that the number should reflect the minimal block
288 alignment. */
289 struct statvfs64 sv;
290
291 if (__fstatvfs64 (fd, &sv) < 0)
292 return -1;
293 return sv.f_frsize;
294 }
295
296 case _PC_SYMLINK_MAX:
297 /* In general there are no limits. If a system has one it should
298 overwrite this case. */
299 return -1;
300 }
301 }
302
303 weak_alias (__fpathconf, fpathconf)
304