libmount: improve function for work with mtab paths

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/shlibs/mount/src/tab_parse.c b/shlibs/mount/src/tab_parse.c
index 5ac51ab8739fe4058d8b6d7ee510eb2afdf8c68b..a1857a44b618bdf74297834607a03b4d22b95f6b 100644 (file)
--- a/shlibs/mount/src/tab_parse.c
+++ b/shlibs/mount/src/tab_parse.c
@@ -13,6 +13,7 @@
 #include <sys/stat.h>
 #include <dirent.h>
 #include <fcntl.h>
+#include <unistd.h>
 
 #include "nls.h"
 #include "at.h"
@@ -383,6 +384,66 @@ int mnt_tab_parse_file(mnt_tab *tb, const char *filename)
        return rc;
 }
 
+static int mnt_tab_parse_dir(mnt_tab *tb, const char *dirname)
+{
+       int n = 0, i;
+       DIR *dir = NULL;
+       struct dirent **namelist = NULL;
+
+       /* TODO: it would be nice to have a scandir() implementaion that
+        *       is able to use already opened directory */
+       n = scandir(dirname, &namelist, NULL, versionsort);
+       if (n <= 0)
+               return 0;
+
+       /* let use "at" functions rather than play crazy games with paths... */
+       dir = opendir(dirname);
+       if (!dir)
+               return -errno;
+
+       for (i = 0; i < n; i++) {
+               struct dirent *d = namelist[i];
+               struct stat st;
+               size_t namesz;
+               FILE *f;
+
+#ifdef _DIRENT_HAVE_D_TYPE
+               if (d->d_type != DT_UNKNOWN && d->d_type != DT_REG &&
+                   d->d_type != DT_LNK)
+                       continue;
+#endif
+               if (*d->d_name == '.')
+                       continue;
+
+#define MNT_MNTTABDIR_EXTSIZ   (sizeof(MNT_MNTTABDIR_EXT) - 1)
+
+               namesz = strlen(d->d_name);
+               if (!namesz || namesz < MNT_MNTTABDIR_EXTSIZ + 1 ||
+                   strcmp(d->d_name + (namesz - MNT_MNTTABDIR_EXTSIZ),
+                           MNT_MNTTABDIR_EXT))
+                               continue;
+
+               if (fstat_at(dirfd(dir), _PATH_MNTTAB_DIR, d->d_name, &st, 0) ||
+                   !S_ISREG(st.st_mode))
+                       continue;
+
+               f = fopen_at(dirfd(dir), _PATH_MNTTAB_DIR,
+                                       d->d_name, O_RDONLY, "r");
+               if (f) {
+                       mnt_tab_parse_stream(tb, f, d->d_name);
+                       fclose(f);
+               }
+       }
+
+       for (i = 0; i < n; i++)
+               free(namelist[i]);
+       free(namelist);
+       if (dir)
+               closedir(dir);
+       return 0;
+}
+
+
 /**
  * mnt_new_tab_from_file:
  * @filename: /etc/{m,fs}tab or /proc/self/mountinfo path
@@ -410,6 +471,28 @@ mnt_tab *mnt_new_tab_from_file(const char *filename)
        return tb;
 }
 
+/**
+ * mnt_new_tab_from_dir
+ * @dirname: for example /etc/fstab.d or /dev/.mount/utabs
+ *
+ * Returns: newly allocated tab on success and NULL in case of error.
+ */
+mnt_tab *mnt_new_tab_from_dir(const char *dirname)
+{
+       mnt_tab *tb;
+
+       assert(dirname);
+
+       if (!dirname)
+               return NULL;
+       tb = mnt_new_tab();
+       if (tb && mnt_tab_parse_dir(tb, dirname) != 0) {
+               mnt_free_tab(tb);
+               tb = NULL;
+       }
+       return tb;
+}
+
 /**
  * mnt_tab_set_parser_errcb:
  * @tab: pointer to table
@@ -450,90 +533,35 @@ int mnt_tab_set_parser_errcb(mnt_tab *tb,
  *
  * See also mnt_tab_set_parser_errcb().
  *
- * Returns: 0 on success (least one record has been successfully parsed) or
- *          negative number in case of error.
+ * Returns: 0 on success or negative number in case of error.
  */
 int mnt_tab_parse_fstab(mnt_tab *tb, const char *filename)
 {
-       int num, n = 0, i;
-       DIR *dir = NULL;
        FILE *f;
-       struct dirent **namelist = NULL;
 
        assert(tb);
+
        if (!tb)
                return -EINVAL;
-
-       num = mnt_tab_get_nents(tb);
-
        if (!filename)
                filename = mnt_get_fstab_path();
 
        f = fopen(filename, "r");
        if (f) {
-               mnt_tab_parse_stream(tb, f, filename);
+               int rc = mnt_tab_parse_stream(tb, f, filename);
                fclose(f);
 
+               if (rc)
+                       return rc;
+
                if (strcmp(filename, _PATH_MNTTAB))
                        /* /etc/fstab.d sould be used together with /etc/fstab only */
-                       goto done;
-       }
-
-       /* TODO: it would be nice to have a scandir() implementaion that
-        *       is able to use already opened directory */
-       n = scandir(_PATH_MNTTAB_DIR, &namelist, NULL, versionsort);
-       if (n <= 0)
-               goto done;
-
-       /* let use "at" functions rather than play crazy games with paths... */
-       dir = opendir(_PATH_MNTTAB_DIR);
-       if (!dir)
-               goto done;
-
-       for (i = 0; i < n; i++) {
-               struct dirent *d = namelist[i];
-               struct stat st;
-               size_t namesz;
-
-#ifdef _DIRENT_HAVE_D_TYPE
-               if (d->d_type != DT_UNKNOWN && d->d_type != DT_REG &&
-                   d->d_type != DT_LNK)
-                       continue;
-#endif
-               if (*d->d_name == '.')
-                       continue;
-
-#define MNT_MNTTABDIR_EXTSIZ   (sizeof(MNT_MNTTABDIR_EXT) - 1)
-
-               namesz = strlen(d->d_name);
-               if (!namesz || namesz < MNT_MNTTABDIR_EXTSIZ + 1 ||
-                   strcmp(d->d_name + (namesz - MNT_MNTTABDIR_EXTSIZ),
-                           MNT_MNTTABDIR_EXT))
-                               continue;
-
-               if (fstat_at(dirfd(dir), _PATH_MNTTAB_DIR, d->d_name, &st, 0) ||
-                   !S_ISREG(st.st_mode))
-                       continue;
-
-               f = fopen_at(dirfd(dir), _PATH_MNTTAB_DIR,
-                                       d->d_name, O_RDONLY, "r");
-               if (f) {
-                       mnt_tab_parse_stream(tb, f, d->d_name);
-                       fclose(f);
-               }
+                       return 0;
        }
-done:
-       for (i = 0; i < n; i++)
-               free(namelist[i]);
-       free(namelist);
-       if (dir)
-               closedir(dir);
-
-       num = mnt_tab_get_nents(tb) - num;
 
-       DBG(TAB, mnt_debug_h(tb, "fstab contains %d records", num));
-
-       return num > 0 ? 0 : -1;
+       if (!access(_PATH_MNTTAB_DIR, R_OK))
+               return mnt_tab_parse_dir(tb, _PATH_MNTTAB_DIR);
+       return 0;
 }
 
 /*
@@ -586,12 +614,8 @@ static mnt_fs *mnt_tab_merge_userspace_fs(mnt_tab *tb, mnt_fs *uf)
  * @tb: table
  * @filename: overwrites default (/etc/mtab or $LIBMOUNT_MTAB) or NULL
  *
- * This function parses /etc/mtab or {/proc/self,/var/run/mount}/mountinfo or
- * /proc/mounts. Note that the /var/run/mount/mountinfo file is optional and
- * contains userspace specific mount options only.
- *
- * Note that /var/run/mount/mountinfo is ignored if /etc/mtab is writable or
- * $LIBMOUNT_MTAB or @filename does not end with "mountinfo" postfix.
+ * This function parses /etc/mtab or /proc/self/mountinfo +
+ * /dev/.mount/utabs/<*>.mtab or /proc/mounts.
  *
  * See also mnt_tab_set_parser_errcb().
  *
@@ -600,22 +624,17 @@ static mnt_fs *mnt_tab_merge_userspace_fs(mnt_tab *tb, mnt_fs *uf)
 int mnt_tab_parse_mtab(mnt_tab *tb, const char *filename)
 {
        int rc;
+       const char *utab = NULL;
 
-       if (!filename)
-               filename = mnt_get_writable_mtab_path();
-
-       /*
-        * Regular mtab file
-        */
-       if (filename && !endswith(filename, "mountinfo")) {
+       if (mnt_has_regular_mtab(&filename, NULL)) {
                rc = mnt_tab_parse_file(tb, filename);
                if (!rc)
                        return 0;
-               filename = NULL;
+               filename = NULL;        /* failed */
        }
 
        /*
-        * useless /etc/mtab or /var/run/mount/mountinfo is supported
+        * useless /etc/mtab
         * -- read kernel information from /proc/self/mountinfo
         */
        rc = mnt_tab_parse_file(tb, _PATH_PROC_MOUNTINFO);
@@ -624,13 +643,11 @@ int mnt_tab_parse_mtab(mnt_tab *tb, const char *filename)
                return mnt_tab_parse_file(tb, _PATH_PROC_MOUNTS);
 
        /*
-        * try to read userspace specific information from
-        * /var/run/mount/mountinfo
+        * try to read userspace specific information from /dev/.mount/utabs/
         */
-       if (filename) {
-               mnt_tab *u_tb = mnt_new_tab_from_file(filename);
-
-               assert(endswith(filename, "mountinfo"));
+       utab = mnt_get_utab_path();
+       if (utab) {
+               mnt_tab *u_tb = mnt_new_tab_from_dir(utab);
 
                if (u_tb) {
                        mnt_fs *u_fs;

diff --git a/shlibs/mount/src/utils.c b/shlibs/mount/src/utils.c
index f2c1bf25b5d6d949bfea832bfb12cb76370fd4e8..9242849658d7c485a343f633c8587b3c5874d9bf 100644 (file)
--- a/shlibs/mount/src/utils.c
+++ b/shlibs/mount/src/utils.c
@@ -407,15 +407,29 @@ done:
 /*
  * Returns 1 if /etc/mtab is a reqular file.
  */
-int mnt_has_regular_mtab(const char **mtab)
+int mnt_has_regular_mtab(const char **mtab, int *writeable)
 {
        struct stat st;
-       const char *x = mnt_get_mtab_path();
+       int rc;
+       const char *x = mtab && *mtab ? *mtab : mnt_get_mtab_path();
 
-       if (mtab)
+       if (mtab && !*mtab)
                *mtab = x;
-
-       return (lstat(x, &st) == 0 && S_ISREG(st.st_mode));
+       rc = (lstat(x, &st) == 0 && S_ISREG(st.st_mode));
+
+       if (writable) {
+               if (rc) {
+                       /* TODO: use utimensat() */
+                       int fd = open(path, O_RDWR, 0644);
+                       if (fd >= 0) {
+                               close(fd);
+                               *writable = 1;
+                               return rc;
+                       }
+               }
+               *writable = 0;
+       }
+       return rc;
 }
 
 /**
@@ -456,27 +470,6 @@ const char *mnt_get_utab_path(void)
        return p ? : MNT_PATH_UTAB;
 }
 
-/**
- * mnt_get_writable_mtab_path:
- *
- * Returns: pointer to the static string with path to mtab or NULL if writable
- *          mtab is unsupported.
- */
-const char *mnt_get_writable_mtab_path(void)
-{
-       struct stat st;
-       const char *path = mnt_get_mtab_path();
-
-       if (lstat(path, &st) && S_ISREG(st.st_mode)) {
-               int fd = open(path, O_RDWR, 0644);
-               if (fd >= 0) {
-                       close(fd);
-                       return path;
-               }
-       }
-
-       return NULL;
-}
 
 /* returns file descriptor or -errno, @name returns uniques filename
  */