From d2e24bb1b485949af2fdd07026380053200a0300 Mon Sep 17 00:00:00 2001 From: Karel Zak Date: Wed, 2 Dec 2015 13:38:51 +0100 Subject: [PATCH 195/197] libmount: fix is-mounted check for btrfs fstab: /dev/sdc /mnt/test btrfs subvol=/anydir /mnt/test /mnt/test2 auto bind and "mount -a" does not detect that /mnt/test2 is already mounted. Reported-by: Stanislav Brabec Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=1816183 Upstream: http://github.com/karelzak/util-linux/commit/352740e88e2c9cb180fe845ce210b1c7b5ad88c7 Signed-off-by: Karel Zak --- libmount/src/tab.c | 38 ++++++++++++++++++++++++++------------ 1 file changed, 26 insertions(+), 12 deletions(-) diff --git a/libmount/src/tab.c b/libmount/src/tab.c index 3ee9c0042..575b33d8c 100644 --- a/libmount/src/tab.c +++ b/libmount/src/tab.c @@ -981,21 +981,33 @@ struct libmnt_fs *mnt_table_get_fs_root(struct libmnt_table *tb, goto dflt; } - /* on btrfs the subvolume is used as fs-root in - * /proc/self/mountinfo, so we have to get the original subvolume - * name from src_fs and prepend the subvolume name to the - * fs-root path + /* It's possible that fstab_fs source is subdirectory on btrfs + * subvolume or anothe bind mount. For example: + * + * /dev/sdc /mnt/test btrfs subvol=/anydir + * /mnt/test/foo /mnt/test2 auto bind + * + * in this case, the root for /mnt/test2 will be /anydir/foo on + * /dev/sdc. It means we have to compose the final root from + * root and src_root. */ src_root = mnt_fs_get_root(src_fs); + + DBG(FS, mnt_debug("source root: %s, source FS root: %s", root, src_root)); + if (src_root && !startswith(root, src_root)) { - size_t sz = strlen(root) + strlen(src_root) + 1; - char *tmp = malloc(sz); - - if (!tmp) - goto err; - snprintf(tmp, sz, "%s%s", src_root, root); - free(root); - root = tmp; + if (strcmp(root, "/") == 0) { + free(root); + root = strdup(src_root); + if (!root) + goto err; + } else { + char *tmp; + if (asprintf(&tmp, "%s%s", src_root, root) < 0) + goto err; + free(root); + root = tmp; + } } } @@ -1138,6 +1150,8 @@ int mnt_table_is_fs_mounted(struct libmnt_table *tb, struct libmnt_fs *fstab_fs) } mnt_reset_iter(&itr, MNT_ITER_FORWARD); + DBG(FS, mnt_debug_h(fstab_fs, "is mounted: src=%s, tgt=%s, root=%s", src, tgt, root)); + while (mnt_table_next_fs(tb, &itr, &fs) == 0) { if (!mnt_fs_streq_srcpath(fs, src)) { -- 2.25.2