diff options
| -rw-r--r-- | mount.cifs.c | 27 | ||||
| -rw-r--r-- | mount.h | 1 | ||||
| -rw-r--r-- | mtab.c | 27 |
3 files changed, 53 insertions, 2 deletions
diff --git a/mount.cifs.c b/mount.cifs.c index 9d7e107..107a5a5 100644 --- a/mount.cifs.c +++ b/mount.cifs.c @@ -1428,10 +1428,11 @@ static int check_mtab(const char *progname, const char *devname, static int add_mtab(char *devname, char *mountpoint, unsigned long flags, const char *fstype) { - int rc = 0; + int rc = 0, tmprc, fd; uid_t uid; char *mount_user = NULL; struct mntent mountent; + struct stat statbuf; FILE *pmntfile; sigset_t mask, oldmask; @@ -1483,6 +1484,23 @@ add_mtab(char *devname, char *mountpoint, unsigned long flags, const char *fstyp goto add_mtab_exit; } + fd = fileno(pmntfile); + if (fd < 0) { + fprintf(stderr, "mntent does not appear to be valid\n"); + unlock_mtab(); + rc = EX_FILEIO; + goto add_mtab_exit; + } + + rc = fstat(fd, &statbuf); + if (rc != 0) { + fprintf(stderr, "unable to fstat open mtab\n"); + endmntent(pmntfile); + unlock_mtab(); + rc = EX_FILEIO; + goto add_mtab_exit; + } + mountent.mnt_fsname = devname; mountent.mnt_dir = mountpoint; mountent.mnt_type = (char *)(void *)fstype; @@ -1514,9 +1532,14 @@ add_mtab(char *devname, char *mountpoint, unsigned long flags, const char *fstyp rc = addmntent(pmntfile, &mountent); if (rc) { fprintf(stderr, "unable to add mount entry to mtab\n"); + ftruncate(fd, statbuf.st_size); + rc = EX_FILEIO; + } + tmprc = my_endmntent(pmntfile, statbuf.st_size); + if (tmprc) { + fprintf(stderr, "error %d detected on close of mtab\n", tmprc); rc = EX_FILEIO; } - endmntent(pmntfile); unlock_mtab(); SAFE_FREE(mountent.mnt_opts); add_mtab_exit: @@ -35,5 +35,6 @@ extern int mtab_unusable(void); extern int lock_mtab(void); extern void unlock_mtab(void); +extern int my_endmntent(FILE *stream, off_t size); #endif /* ! _MOUNT_H_ */ @@ -251,3 +251,30 @@ lock_mtab (void) { return 0; } +/* + * Call fflush and fsync on the mtab, and then endmntent. If either fflush + * or fsync fails, then truncate the file back to "size". endmntent is called + * unconditionally, and the errno (if any) from fflush and fsync are returned. + */ +int +my_endmntent(FILE *stream, off_t size) +{ + int rc, fd; + + fd = fileno(stream); + if (fd < 0) + return -EBADF; + + rc = fflush(stream); + if (!rc) + rc = fsync(fd); + + /* truncate file back to "size" -- best effort here */ + if (rc) { + rc = errno; + ftruncate(fd, size); + } + + endmntent(stream); + return rc; +} |