4.13-stable review patch. If anyone has any objections, please let me know.
------------------
From: Amir Goldstein <amir73il@xxxxxxxxx>
commit 5820dc0888d302ac05f8b91ffdf7e4e53b4fbf53 upstream.
Use the ovl_lock_rename_workdir() helper which requires
unlock_rename() only on lock success.
Fixes: ("fd210b7d67ee ovl: move copy up lock out")
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/overlayfs/copy_up.c | 6 ++----
fs/overlayfs/dir.c | 20 --------------------
fs/overlayfs/overlayfs.h | 1 +
fs/overlayfs/util.c | 19 +++++++++++++++++++
4 files changed, 22 insertions(+), 24 deletions(-)
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -561,10 +561,8 @@ static int ovl_do_copy_up(struct ovl_cop
c->tmpfile = true;
err = ovl_copy_up_locked(c);
} else {
- err = -EIO;
- if (lock_rename(c->workdir, c->destdir) != NULL) {
- pr_err("overlayfs: failed to lock workdir+upperdir\n");
- } else {
+ err = ovl_lock_rename_workdir(c->workdir, c->destdir);
+ if (!err) {
err = ovl_copy_up_locked(c);
unlock_rename(c->workdir, c->destdir);
}
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -216,26 +216,6 @@ out_unlock:
return err;
}
-static int ovl_lock_rename_workdir(struct dentry *workdir,
- struct dentry *upperdir)
-{
- /* Workdir should not be the same as upperdir */
- if (workdir == upperdir)
- goto err;
-
- /* Workdir should not be subdir of upperdir and vice versa */
- if (lock_rename(workdir, upperdir) != NULL)
- goto err_unlock;
-
- return 0;
-
-err_unlock:
- unlock_rename(workdir, upperdir);
-err:
- pr_err("overlayfs: failed to lock workdir+upperdir\n");
- return -EIO;
-}
-
static struct dentry *ovl_clear_empty(struct dentry *dentry,
struct list_head *list)
{
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -234,6 +234,7 @@ bool ovl_inuse_trylock(struct dentry *de
void ovl_inuse_unlock(struct dentry *dentry);
int ovl_nlink_start(struct dentry *dentry, bool *locked);
void ovl_nlink_end(struct dentry *dentry, bool locked);
+int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
static inline bool ovl_is_impuredir(struct dentry *dentry)
{
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -548,3 +548,22 @@ void ovl_nlink_end(struct dentry *dentry
mutex_unlock(&OVL_I(d_inode(dentry))->lock);
}
}
+
+int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir)
+{
+ /* Workdir should not be the same as upperdir */
+ if (workdir == upperdir)
+ goto err;
+
+ /* Workdir should not be subdir of upperdir and vice versa */
+ if (lock_rename(workdir, upperdir) != NULL)
+ goto err_unlock;
+
+ return 0;
+
+err_unlock:
+ unlock_rename(workdir, upperdir);
+err:
+ pr_err("overlayfs: failed to lock workdir+upperdir\n");
+ return -EIO;
+}