Unionfs: remove unnecessary locking in follow-link

Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>

diff --git a/fs/unionfs/inode.c b/fs/unionfs/inode.c
index 8083d13b559d01d21e6fc570da52da442094b57e..44fc2fc6221b0253f9b70bc94ed6855c87bda6c6 100644 (file)
--- a/fs/unionfs/inode.c
+++ b/fs/unionfs/inode.c
@@ -842,7 +842,8 @@ out:
  * nor do we need to revalidate it either.  It is safe to not lock our
  * dentry here, nor revalidate it, because unionfs_follow_link does not do
  * anything (prior to calling ->readlink) which could become inconsistent
- * due to branch management.
+ * due to branch management.  We also don't need to lock our super because
+ * this function isn't affected by branch-management.
  */
 static void *unionfs_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
@@ -850,8 +851,6 @@ static void *unionfs_follow_link(struct dentry *dentry, struct nameidata *nd)
        int len = PAGE_SIZE, err;
        mm_segment_t old_fs;
 
-       unionfs_read_lock(dentry->d_sb);
-
        /* This is freed by the put_link method assuming a successful call. */
        buf = kmalloc(len, GFP_KERNEL);
        if (unlikely(!buf)) {
@@ -875,7 +874,6 @@ static void *unionfs_follow_link(struct dentry *dentry, struct nameidata *nd)
 
 out:
        unionfs_check_dentry(dentry);
-       unionfs_read_unlock(dentry->d_sb);
        return ERR_PTR(err);
 }