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authorLinus Torvalds <torvalds@linux-foundation.org>2015-05-27 09:47:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-05-27 09:47:57 -0700
commit3cfd4ba7d37b52eb965ed05209647072932dfd0a (patch)
tree099660db38046f017104820623e4431dd126b757 /fs
parent1b887bf31dd6e2f8cef80d205d6e9949a7dd98cc (diff)
parentcc6f67bcafcb6bbbb2d1be1603dcd95125a52800 (diff)
downloadkernel-3cfd4ba7d37b52eb965ed05209647072932dfd0a.tar.gz
Merge branch 'overlayfs-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull two overlayfs fixes from Miklos Szeredi: "Overlayfs rmdir() failed to check for emptiness in one case; this was introduced in 4.0. The other bug was there since day one: failure to mount if upper fs is full, which bit some OpenWRT folks" * 'overlayfs-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: mount read-only if workdir can't be created ovl: don't remove non-empty opaque directory
Diffstat (limited to 'fs')
-rw-r--r--fs/overlayfs/copy_up.c3
-rw-r--r--fs/overlayfs/dir.c33
-rw-r--r--fs/overlayfs/super.c10
3 files changed, 36 insertions, 10 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 24f640441bd9..84d693d37428 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -299,6 +299,9 @@ int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
struct cred *override_cred;
char *link = NULL;
+ if (WARN_ON(!workdir))
+ return -EROFS;
+
ovl_path_upper(parent, &parentpath);
upperdir = parentpath.dentry;
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index d139405d2bfa..692ceda3bc21 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -222,6 +222,9 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry,
struct kstat stat;
int err;
+ if (WARN_ON(!workdir))
+ return ERR_PTR(-EROFS);
+
err = ovl_lock_rename_workdir(workdir, upperdir);
if (err)
goto out;
@@ -322,6 +325,9 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
struct dentry *newdentry;
int err;
+ if (WARN_ON(!workdir))
+ return -EROFS;
+
err = ovl_lock_rename_workdir(workdir, upperdir);
if (err)
goto out;
@@ -506,11 +512,28 @@ static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir)
struct dentry *opaquedir = NULL;
int err;
- if (is_dir && OVL_TYPE_MERGE_OR_LOWER(ovl_path_type(dentry))) {
- opaquedir = ovl_check_empty_and_clear(dentry);
- err = PTR_ERR(opaquedir);
- if (IS_ERR(opaquedir))
- goto out;
+ if (WARN_ON(!workdir))
+ return -EROFS;
+
+ if (is_dir) {
+ if (OVL_TYPE_MERGE_OR_LOWER(ovl_path_type(dentry))) {
+ opaquedir = ovl_check_empty_and_clear(dentry);
+ err = PTR_ERR(opaquedir);
+ if (IS_ERR(opaquedir))
+ goto out;
+ } else {
+ LIST_HEAD(list);
+
+ /*
+ * When removing an empty opaque directory, then it
+ * makes no sense to replace it with an exact replica of
+ * itself. But emptiness still needs to be checked.
+ */
+ err = ovl_check_empty_dir(dentry, &list);
+ ovl_cache_free(&list);
+ if (err)
+ goto out;
+ }
}
err = ovl_lock_rename_workdir(workdir, upperdir);
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++)