/**
* mnt_table_parse_mtab:
* @tb: table
* @filename: overwrites default (/etc/mtab or $LIBMOUNT_MTAB) or NULL
*
* This function parses /etc/mtab or /proc/self/mountinfo +
* /run/mount/utabs or /proc/mounts.
*
* See also mnt_table_set_parser_errcb().
*
* Returns: 0 on success or negative number in case of error.
*/
int mnt_table_parse_mtab(struct libmnt_table *tb, const char *filename)
{
int rc;
const char *utab = NULL;
struct libmnt_table *u_tb;
assert(tb);
if (mnt_has_regular_mtab(&filename, NULL)) {
DBG(TAB, mnt_debug_h(tb, "force %s usage", filename));
rc = mnt_table_parse_file(tb, filename);
if (!rc)
return 0;
filename = NULL; /* failed */
}
/*
* useless /etc/mtab
* -- read kernel information from /proc/self/mountinfo
*/
tb->fmt = MNT_FMT_MOUNTINFO;
rc = mnt_table_parse_file(tb, _PATH_PROC_MOUNTINFO);
if (rc) {
/* hmm, old kernel? ...try /proc/mounts */
tb->fmt = MNT_FMT_MTAB;
return mnt_table_parse_file(tb, _PATH_PROC_MOUNTS);
}
if (mnt_table_get_nents(tb) == 0)
return 0; /* empty, ignore utab */
/*
* try to read the user specific information from /run/mount/utabs
*/
utab = mnt_get_utab_path();
if (!utab || is_file_empty(utab))
return 0;
u_tb = mnt_new_table();
if (!u_tb)
return -ENOMEM;
u_tb->fmt = MNT_FMT_UTAB;
mnt_table_set_parser_fltrcb(u_tb, tb->fltrcb, tb->fltrcb_data);
if (mnt_table_parse_file(u_tb, utab) == 0) {
struct libmnt_fs *u_fs;
struct libmnt_iter itr;
mnt_reset_iter(&itr, MNT_ITER_BACKWARD);
/* merge user options into mountinfo from the kernel */
while(mnt_table_next_fs(u_tb, &itr, &u_fs) == 0)
mnt_table_merge_user_fs(tb, u_fs);
}
mnt_unref_table(u_tb);
return 0;
}
/**
* mnt_table_parse_mtab:
* @tb: table
* @filename: overwrites default (/etc/mtab or $LIBMOUNT_MTAB) or NULL
*
* This function parses /etc/mtab or /proc/self/mountinfo +
* /run/mount/utabs or /proc/mounts.
*
* See also mnt_table_set_parser_errcb().
*
* Returns: 0 on success or negative number in case of error.
*/
int mnt_table_parse_mtab(struct libmnt_table *tb, const char *filename)
{
int rc;
const char *utab = NULL;
if (mnt_has_regular_mtab(&filename, NULL)) {
DBG(TAB, mnt_debug_h(tb, "force %s usage", filename));
rc = mnt_table_parse_file(tb, filename);
if (!rc)
return 0;
filename = NULL; /* failed */
}
/*
* useless /etc/mtab
* -- read kernel information from /proc/self/mountinfo
*/
tb->fmt = MNT_FMT_MOUNTINFO;
rc = mnt_table_parse_file(tb, _PATH_PROC_MOUNTINFO);
if (rc) {
/* hmm, old kernel? ...try /proc/mounts */
tb->fmt = MNT_FMT_MTAB;
return mnt_table_parse_file(tb, _PATH_PROC_MOUNTS);
}
/*
* try to read user specific information from /run/mount/utabs
*/
utab = mnt_get_utab_path();
if (utab) {
struct libmnt_table *u_tb = __mnt_new_table_from_file(utab, MNT_FMT_UTAB);
if (u_tb) {
struct libmnt_fs *u_fs;
struct libmnt_iter itr;
mnt_reset_iter(&itr, MNT_ITER_BACKWARD);
/* merge user options into mountinfo from kernel */
while(mnt_table_next_fs(u_tb, &itr, &u_fs) == 0)
mnt_table_merge_user_fs(tb, u_fs);
mnt_free_table(u_tb);
}
}
return 0;
}
/*
* Don't export this to libmount API -- utab is private library stuff.
*
* If the file does not exist and @writable argument is not NULL then it will
* try to create the directory (e.g. /run/mount) and the file.
*
* Returns: 1 if utab is a regular file, and 0 in case of
* error (check errno for more details).
*/
int mnt_has_regular_utab(const char **utab, int *writable)
{
struct stat st;
int rc;
const char *filename = utab && *utab ? *utab : mnt_get_utab_path();
if (writable)
*writable = 0;
if (utab && !*utab)
*utab = filename;
DBG(UTILS, mnt_debug("utab: %s", filename));
rc = lstat(filename, &st);
if (rc == 0) {
/* file exist */
if (S_ISREG(st.st_mode)) {
if (writable)
*writable = !try_write(filename);
return 1;
}
goto done; /* it's not regular file */
}
if (writable) {
char *dirname = strdup(filename);
if (!dirname)
goto done;
stripoff_last_component(dirname); /* remove filename */
rc = mkdir(dirname, S_IWUSR|
S_IRUSR|S_IRGRP|S_IROTH|
S_IXUSR|S_IXGRP|S_IXOTH);
free(dirname);
if (rc && errno != EEXIST)
goto done; /* probably EACCES */
*writable = !try_write(filename);
if (*writable)
return 1;
}
done:
DBG(UTILS, mnt_debug("%s: irregular/non-writable file", filename));
return 0;
}
/* Check if there is something important in the utab file. The parsed utab is
* stored in context->utab and deallocated by mnt_free_context().
*
* This function exists to avoid (if possible) /proc/self/mountinfo usage, so
* don't use thigs like mnt_resolve_target(), mnt_context_get_mtab() etc here.
* See lookup_umount_fs() for more details.
*/
static int has_utab_entry(struct libmnt_context *cxt, const char *target)
{
struct libmnt_cache *cache = NULL;
struct libmnt_fs *fs;
struct libmnt_iter itr;
char *cn = NULL;
int rc = 0;
assert(cxt);
if (!cxt->utab) {
const char *path = mnt_get_utab_path();
if (!path || is_file_empty(path))
return 0;
cxt->utab = mnt_new_table();
if (!cxt->utab)
return 0;
cxt->utab->fmt = MNT_FMT_UTAB;
if (mnt_table_parse_file(cxt->utab, path))
return 0;
}
/* paths in utab are canonicalized */
cache = mnt_context_get_cache(cxt);
cn = mnt_resolve_path(target, cache);
mnt_reset_iter(&itr, MNT_ITER_BACKWARD);
while (mnt_table_next_fs(cxt->utab, &itr, &fs) == 0) {
if (mnt_fs_streq_target(fs, cn)) {
rc = 1;
break;
}
}
if (!cache)
free(cn);
return rc;
}
/* default filename is /proc/self/mountinfo
*/
int __mnt_table_parse_mtab(struct libmnt_table *tb, const char *filename,
struct libmnt_table *u_tb)
{
int rc = 0, priv_utab = 0;
assert(tb);
if (filename)
DBG(TAB, ul_debugobj(tb, "%s reuested as mtab", filename));
#ifdef USE_LIBMOUNT_SUPPORT_MTAB
if (mnt_has_regular_mtab(&filename, NULL)) {
DBG(TAB, ul_debugobj(tb, "force mtab usage [filename=%s]", filename));
rc = mnt_table_parse_file(tb, filename);
/*
* If @filename forces us to read from /proc then also read
* utab file to merge userspace mount options.
*/
if (rc == 0 && is_mountinfo(tb))
goto read_utab;
if (!rc)
return 0;
filename = NULL; /* failed */
} else
filename = NULL; /* mtab useless */
#endif
if (!filename || strcmp(filename, _PATH_PROC_MOUNTINFO) == 0) {
filename = _PATH_PROC_MOUNTINFO;
tb->fmt = MNT_FMT_MOUNTINFO;
DBG(TAB, ul_debugobj(tb, "mtab parse: #1 read mountinfo"));
} else
tb->fmt = MNT_FMT_GUESS;
rc = mnt_table_parse_file(tb, filename);
if (rc) {
/* hmm, old kernel? ...try /proc/mounts */
tb->fmt = MNT_FMT_MTAB;
return mnt_table_parse_file(tb, _PATH_PROC_MOUNTS);
}
if (!is_mountinfo(tb))
return 0;
#ifdef USE_LIBMOUNT_SUPPORT_MTAB
read_utab:
#endif
DBG(TAB, ul_debugobj(tb, "mtab parse: #2 read utab"));
if (mnt_table_get_nents(tb) == 0)
return 0; /* empty, ignore utab */
/*
* try to read the user specific information from /run/mount/utabs
*/
if (!u_tb) {
const char *utab = mnt_get_utab_path();
if (!utab || is_file_empty(utab))
return 0;
u_tb = mnt_new_table();
if (!u_tb)
return -ENOMEM;
u_tb->fmt = MNT_FMT_UTAB;
mnt_table_set_parser_fltrcb(u_tb, tb->fltrcb, tb->fltrcb_data);
rc = mnt_table_parse_file(u_tb, utab);
priv_utab = 1;
}
DBG(TAB, ul_debugobj(tb, "mtab parse: #3 merge utab"));
if (rc == 0) {
struct libmnt_fs *u_fs;
struct libmnt_iter itr;
mnt_reset_iter(&itr, MNT_ITER_BACKWARD);
/* merge user options into mountinfo from the kernel */
while(mnt_table_next_fs(u_tb, &itr, &u_fs) == 0)
mnt_table_merge_user_fs(tb, u_fs);
}
if (priv_utab)
mnt_unref_table(u_tb);
return 0;
}
