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| author | Miklos Szeredi <mszeredi@suse.cz> | 2015-05-19 14:30:12 +0200 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@suse.cz> | 2015-05-19 14:30:12 +0200 |
| commit | cc6f67bcafcb6bbbb2d1be1603dcd95125a52800 (patch) | |
| tree | 0d3cb24661ad0c375540791ec24c6fc80760f5b3 /fs/overlayfs/super.c | |
| parent | d377c5eb54dd05aeb3094b7740252d19ba7791f7 (diff) | |
| download | linux-cc6f67bcafcb6bbbb2d1be1603dcd95125a52800.tar.gz linux-cc6f67bcafcb6bbbb2d1be1603dcd95125a52800.tar.bz2 linux-cc6f67bcafcb6bbbb2d1be1603dcd95125a52800.zip | |
ovl: mount read-only if workdir can't be created
OpenWRT folks reported that overlayfs fails to mount if upper fs is full,
because workdir can't be created. Wordir creation can fail for various
other reasons too.
There's no reason that the mount itself should fail, overlayfs can work
fine without a workdir, as long as the overlay isn't modified.
So mount it read-only and don't allow remounting read-write.
Add a couple of WARN_ON()s for the impossible case of workdir being used
despite being read-only.
Reported-by: Bastian Bittorf <bittorf@bluebottle.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: <stable@vger.kernel.org> # v3.18+
Diffstat (limited to 'fs/overlayfs/super.c')
| -rw-r--r-- | fs/overlayfs/super.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 5f0d1993e6e3..bf8537c7f455 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -529,7 +529,7 @@ static int ovl_remount(struct super_block *sb, int *flags, char *data) { struct ovl_fs *ufs = sb->s_fs_info; - if (!(*flags & MS_RDONLY) && !ufs->upper_mnt) + if (!(*flags & MS_RDONLY) && (!ufs->upper_mnt || !ufs->workdir)) return -EROFS; return 0; @@ -925,9 +925,10 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) ufs->workdir = ovl_workdir_create(ufs->upper_mnt, workpath.dentry); err = PTR_ERR(ufs->workdir); if (IS_ERR(ufs->workdir)) { - pr_err("overlayfs: failed to create directory %s/%s\n", - ufs->config.workdir, OVL_WORKDIR_NAME); - goto out_put_upper_mnt; + pr_warn("overlayfs: failed to create directory %s/%s (errno: %i); mounting read-only\n", + ufs->config.workdir, OVL_WORKDIR_NAME, -err); + sb->s_flags |= MS_RDONLY; + ufs->workdir = NULL; } } @@ -997,7 +998,6 @@ out_put_lower_mnt: kfree(ufs->lower_mnt); out_put_workdir: dput(ufs->workdir); -out_put_upper_mnt: mntput(ufs->upper_mnt); out_put_lowerpath: for (i = 0; i < numlower; i++) |