1 | /* Copyright (C) 1998-2016 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998. |
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, see |
17 | <http://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <assert.h> |
20 | #include <errno.h> |
21 | #include <mntent.h> |
22 | #include <paths.h> |
23 | #include <stdbool.h> |
24 | #include <stdio_ext.h> |
25 | #include <string.h> |
26 | #include <sys/mount.h> |
27 | #include <sys/stat.h> |
28 | #include <sys/statfs.h> |
29 | #include <sys/statvfs.h> |
30 | #include "linux_fsinfo.h" |
31 | #include <kernel-features.h> |
32 | |
33 | |
34 | /* Special internal-only bit value. */ |
35 | #define ST_VALID 0x0020 |
36 | |
37 | |
38 | #ifndef STATFS |
39 | # define STATFS statfs |
40 | # define STATVFS statvfs |
41 | # define INTERNAL_STATVFS __internal_statvfs |
42 | |
43 | |
44 | # ifndef __ASSUME_STATFS_F_FLAGS |
45 | int |
46 | __statvfs_getflags (const char *name, int fstype, int fd) |
47 | { |
48 | struct stat64 st; |
49 | |
50 | if ((fd < 0 ? stat64 (name, &st) : fstat64 (fd, &st)) < 0) |
51 | return 0; |
52 | |
53 | const char *fsname = NULL; |
54 | const char *fsname2 = NULL; |
55 | const char *fsname3 = NULL; |
56 | |
57 | /* Map the filesystem type we got from the statfs call to a string. */ |
58 | switch (fstype) |
59 | { |
60 | case EXT2_SUPER_MAGIC: |
61 | fsname = "ext4" ; |
62 | fsname2 = "ext3" ; |
63 | fsname3 = "ext2" ; |
64 | break; |
65 | case DEVPTS_SUPER_MAGIC: |
66 | fsname= "devpts" ; |
67 | break; |
68 | case SHMFS_SUPER_MAGIC: |
69 | fsname = "tmpfs" ; |
70 | break; |
71 | case PROC_SUPER_MAGIC: |
72 | fsname = "proc" ; |
73 | break; |
74 | case USBDEVFS_SUPER_MAGIC: |
75 | fsname = "usbdevfs" ; |
76 | break; |
77 | case AUTOFS_SUPER_MAGIC: |
78 | fsname = "autofs" ; |
79 | break; |
80 | case NFS_SUPER_MAGIC: |
81 | fsname = "nfs" ; |
82 | break; |
83 | case SYSFS_MAGIC: |
84 | fsname = "sysfs" ; |
85 | break; |
86 | case REISERFS_SUPER_MAGIC: |
87 | fsname = "reiserfs" ; |
88 | break; |
89 | case XFS_SUPER_MAGIC: |
90 | fsname = "xfs" ; |
91 | break; |
92 | case JFS_SUPER_MAGIC: |
93 | fsname = "jfs" ; |
94 | break; |
95 | case HPFS_SUPER_MAGIC: |
96 | fsname = "hpfs" ; |
97 | break; |
98 | case DEVFS_SUPER_MAGIC: |
99 | fsname = "devfs" ; |
100 | break; |
101 | case ISOFS_SUPER_MAGIC: |
102 | fsname = "iso9660" ; |
103 | break; |
104 | case MSDOS_SUPER_MAGIC: |
105 | fsname = "msdos" ; |
106 | break; |
107 | case NTFS_SUPER_MAGIC: |
108 | fsname = "ntfs" ; |
109 | break; |
110 | case LOGFS_MAGIC_U32: |
111 | fsname = "logfs" ; |
112 | break; |
113 | case BTRFS_SUPER_MAGIC: |
114 | fsname = "btrfs" ; |
115 | break; |
116 | case CGROUP_SUPER_MAGIC: |
117 | fsname = "cgroup" ; |
118 | break; |
119 | case LUSTRE_SUPER_MAGIC: |
120 | fsname = "lustre" ; |
121 | break; |
122 | case F2FS_SUPER_MAGIC: |
123 | fsname = "f2fs" ; |
124 | break; |
125 | case EFIVARFS_MAGIC: |
126 | fsname = "efivarfs" ; |
127 | break; |
128 | } |
129 | |
130 | FILE *mtab = __setmntent ("/proc/mounts" , "r" ); |
131 | if (mtab == NULL) |
132 | mtab = __setmntent (_PATH_MOUNTED, "r" ); |
133 | |
134 | int result = 0; |
135 | if (mtab != NULL) |
136 | { |
137 | bool success = false; |
138 | struct mntent mntbuf; |
139 | char tmpbuf[1024]; |
140 | |
141 | /* No locking needed. */ |
142 | (void) __fsetlocking (mtab, FSETLOCKING_BYCALLER); |
143 | |
144 | again: |
145 | while (__getmntent_r (mtab, &mntbuf, tmpbuf, sizeof (tmpbuf))) |
146 | { |
147 | /* In a first round we look for a given mount point, if |
148 | we have a name. */ |
149 | if (name != NULL && strcmp (name, mntbuf.mnt_dir) != 0) |
150 | continue; |
151 | /* We need to look at the entry only if the filesystem |
152 | name matches. If we have a filesystem name. */ |
153 | else if (fsname != NULL |
154 | && strcmp (fsname, mntbuf.mnt_type) != 0 |
155 | && (fsname2 == NULL |
156 | || strcmp (fsname2, mntbuf.mnt_type) != 0) |
157 | && (fsname3 == NULL |
158 | || strcmp (fsname3, mntbuf.mnt_type) != 0)) |
159 | continue; |
160 | |
161 | /* Find out about the device the current entry is for. */ |
162 | struct stat64 fsst; |
163 | if (stat64 (mntbuf.mnt_dir, &fsst) >= 0 |
164 | && st.st_dev == fsst.st_dev) |
165 | { |
166 | /* Bingo, we found the entry for the device FD is on. |
167 | Now interpret the option string. */ |
168 | char *cp = mntbuf.mnt_opts; |
169 | char *opt; |
170 | |
171 | while ((opt = strsep (&cp, "," )) != NULL) |
172 | if (strcmp (opt, "ro" ) == 0) |
173 | result |= ST_RDONLY; |
174 | else if (strcmp (opt, "nosuid" ) == 0) |
175 | result |= ST_NOSUID; |
176 | else if (strcmp (opt, "noexec" ) == 0) |
177 | result |= ST_NOEXEC; |
178 | else if (strcmp (opt, "nodev" ) == 0) |
179 | result |= ST_NODEV; |
180 | else if (strcmp (opt, "sync" ) == 0) |
181 | result |= ST_SYNCHRONOUS; |
182 | else if (strcmp (opt, "mand" ) == 0) |
183 | result |= ST_MANDLOCK; |
184 | else if (strcmp (opt, "noatime" ) == 0) |
185 | result |= ST_NOATIME; |
186 | else if (strcmp (opt, "nodiratime" ) == 0) |
187 | result |= ST_NODIRATIME; |
188 | else if (strcmp (opt, "relatime" ) == 0) |
189 | result |= ST_RELATIME; |
190 | |
191 | /* We can stop looking for more entries. */ |
192 | success = true; |
193 | break; |
194 | } |
195 | } |
196 | /* Maybe the kernel names for the filesystems changed or the |
197 | statvfs call got a name which was not the mount point. Check |
198 | again, this time without checking for name matches first. */ |
199 | if (! success && (name != NULL || fsname != NULL)) |
200 | { |
201 | if (name != NULL) |
202 | /* Try without a mount point name. */ |
203 | name = NULL; |
204 | else |
205 | { |
206 | /* Try without a filesystem name. */ |
207 | assert (fsname != NULL); |
208 | fsname = fsname2 = fsname3 = NULL; |
209 | } |
210 | |
211 | /* It is not strictly allowed to use rewind here. But |
212 | this code is part of the implementation so it is |
213 | acceptable. */ |
214 | rewind (mtab); |
215 | |
216 | goto again; |
217 | } |
218 | |
219 | /* Close the file. */ |
220 | __endmntent (mtab); |
221 | } |
222 | |
223 | return result; |
224 | } |
225 | # endif |
226 | #else |
227 | extern int __statvfs_getflags (const char *name, int fstype, int fd); |
228 | #endif |
229 | |
230 | |
231 | void |
232 | INTERNAL_STATVFS (const char *name, struct STATVFS *buf, |
233 | struct STATFS *fsbuf, int fd) |
234 | { |
235 | /* Now fill in the fields we have information for. */ |
236 | buf->f_bsize = fsbuf->f_bsize; |
237 | /* Linux has the f_frsize size only in later version of the kernel. |
238 | If the value is not filled in use f_bsize. */ |
239 | buf->f_frsize = fsbuf->f_frsize ?: fsbuf->f_bsize; |
240 | buf->f_blocks = fsbuf->f_blocks; |
241 | buf->f_bfree = fsbuf->f_bfree; |
242 | buf->f_bavail = fsbuf->f_bavail; |
243 | buf->f_files = fsbuf->f_files; |
244 | buf->f_ffree = fsbuf->f_ffree; |
245 | if (sizeof (buf->f_fsid) == sizeof (fsbuf->f_fsid)) |
246 | /* The shifting uses 'unsigned long long int' even though the target |
247 | field might only have 32 bits. This is OK since the 'if' branch |
248 | is not used in this case but the compiler would still generate |
249 | warnings. */ |
250 | buf->f_fsid = ((fsbuf->f_fsid.__val[0] |
251 | & ((1ULL << (8 * sizeof (fsbuf->f_fsid.__val[0]))) - 1)) |
252 | | ((unsigned long long int) fsbuf->f_fsid.__val[1] |
253 | << (8 * (sizeof (buf->f_fsid) |
254 | - sizeof (fsbuf->f_fsid.__val[0]))))); |
255 | else |
256 | /* We cannot help here. The statvfs element is not large enough to |
257 | contain both words of the statfs f_fsid field. */ |
258 | buf->f_fsid = fsbuf->f_fsid.__val[0]; |
259 | #ifdef _STATVFSBUF_F_UNUSED |
260 | buf->__f_unused = 0; |
261 | #endif |
262 | buf->f_namemax = fsbuf->f_namelen; |
263 | memset (buf->__f_spare, '\0', sizeof (buf->__f_spare)); |
264 | |
265 | /* What remains to do is to fill the fields f_favail and f_flag. */ |
266 | |
267 | /* XXX I have no idea how to compute f_favail. Any idea??? */ |
268 | buf->f_favail = buf->f_ffree; |
269 | |
270 | #ifndef __ASSUME_STATFS_F_FLAGS |
271 | if ((fsbuf->f_flags & ST_VALID) == 0) |
272 | /* Determining the flags is tricky. We have to read /proc/mounts or |
273 | the /etc/mtab file and search for the entry which matches the given |
274 | file. The way we can test for matching filesystem is using the |
275 | device number. */ |
276 | buf->f_flag = __statvfs_getflags (name, fsbuf->f_type, fd); |
277 | else |
278 | #endif |
279 | buf->f_flag = fsbuf->f_flags ^ ST_VALID; |
280 | } |
281 | |