1 files changed, 26 insertions, 27 deletions

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 953e8432b0ae..1af963e66e3c 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -565,50 +565,49 @@ void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
  *      Drop dentry for @sd.  @sd must have been unlinked from its
  *      parent on entry to this function such that it can't be looked
  *      up anymore.
- *
- *      @sd->s_dentry which is protected with sysfs_assoc_lock points
- *      to the currently associated dentry but we're not holding a
- *      reference to it and racing with dput().  Grab dcache_lock and
- *      verify dentry before dropping it.  If @sd->s_dentry is NULL or
- *      dput() beats us, no need to bother.
  */
 static void sysfs_drop_dentry(struct sysfs_dirent *sd)
 {
-        struct dentry *dentry = NULL;
         struct inode *inode;
+        struct dentry *dentry;
+
+        inode = ilookup(sysfs_sb, sd->s_ino);
+        if (!inode)
+                return;
 
-        /* We're not holding a reference to ->s_dentry dentry but the
-         * field will stay valid as long as sysfs_assoc_lock is held.
+        /* Drop any existing dentries associated with sd.
+         *
+         * For the dentry to be properly freed we need to grab a
+         * reference to the dentry under the dcache lock,  unhash it,
+         * and then put it.  The playing with the dentry count allows
+         * dput to immediately free the dentry  if it is not in use.
          */
-        spin_lock(&sysfs_assoc_lock);
+repeat:
         spin_lock(&dcache_lock);
-
-        /* drop dentry if it's there and dput() didn't kill it yet */
-        if (sd->s_dentry && sd->s_dentry->d_inode) {
-                dentry = dget_locked(sd->s_dentry);
+        list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
+                if (d_unhashed(dentry))
+                        continue;
+                dget_locked(dentry);
                 spin_lock(&dentry->d_lock);
                 __d_drop(dentry);
                 spin_unlock(&dentry->d_lock);
+                spin_unlock(&dcache_lock);
+                dput(dentry);
+                goto repeat;
         }
-
         spin_unlock(&dcache_lock);
-        spin_unlock(&sysfs_assoc_lock);
-
-        dput(dentry);
 
         /* adjust nlink and update timestamp */
-        inode = ilookup(sysfs_sb, sd->s_ino);
-        if (inode) {
-                mutex_lock(&inode->i_mutex);
+        mutex_lock(&inode->i_mutex);
 
-                inode->i_ctime = CURRENT_TIME;
+        inode->i_ctime = CURRENT_TIME;
+        drop_nlink(inode);
+        if (sysfs_type(sd) == SYSFS_DIR)
                 drop_nlink(inode);
-                if (sysfs_type(sd) == SYSFS_DIR)
-                        drop_nlink(inode);
 
-                mutex_unlock(&inode->i_mutex);
-                iput(inode);
-        }
+        mutex_unlock(&inode->i_mutex);
+
+        iput(inode);
 }
 
 /**