Merge branch 'master' of /pub/scm/linux/kernel/git/torvalds/linux-2.6

1 files changed, 31 insertions, 9 deletions

diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index a54a946a50ae..edf5b6bddb52 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -146,17 +146,17 @@ static int autofs4_dir_open(struct inode *inode, struct file *file)
 
         if (d_mountpoint(dentry)) {
                 struct file *fp = NULL;
-                struct vfsmount *fp_mnt = mntget(mnt);
-                struct dentry *fp_dentry = dget(dentry);
+                struct path fp_path = { .dentry = dentry, .mnt = mnt };
 
-                if (!autofs4_follow_mount(&fp_mnt, &fp_dentry)) {
-                        dput(fp_dentry);
-                        mntput(fp_mnt);
+                path_get(&fp_path);
+
+                if (!autofs4_follow_mount(&fp_path.mnt, &fp_path.dentry)) {
+                        path_put(&fp_path);
                         dcache_dir_close(inode, file);
                         goto out;
                 }
 
-                fp = dentry_open(fp_dentry, fp_mnt, file->f_flags);
+                fp = dentry_open(fp_path.dentry, fp_path.mnt, file->f_flags);
                 status = PTR_ERR(fp);
                 if (IS_ERR(fp)) {
                         dcache_dir_close(inode, file);
@@ -242,7 +242,8 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags)
 {
         struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
         struct autofs_info *ino = autofs4_dentry_ino(dentry);
-        int status = 0;
+        struct dentry *new;
+        int status;
 
         /* Block on any pending expiry here; invalidate the dentry
            when expiration is done to trigger mount request with a new
@@ -318,7 +319,28 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags)
         spin_lock(&dentry->d_lock);
         dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
         spin_unlock(&dentry->d_lock);
-        return status;
+
+        /*
+         * The dentry that is passed in from lookup may not be the one
+         * we end up using, as mkdir can create a new one.  If this
+         * happens, and another process tries the lookup at the same time,
+         * it will set the PENDING flag on this new dentry, but add itself
+         * to our waitq.  Then, if after the lookup succeeds, the first
+         * process that requested the mount performs another lookup of the
+         * same directory, it will show up as still pending!  So, we need
+         * to redo the lookup here and clear pending on that dentry.
+         */
+        if (d_unhashed(dentry)) {
+                new = d_lookup(dentry->d_parent, &dentry->d_name);
+                if (new) {
+                        spin_lock(&new->d_lock);
+                        new->d_flags &= ~DCACHE_AUTOFS_PENDING;
+                        spin_unlock(&new->d_lock);
+                        dput(new);
+                }
+        }
+
+        return 0;
 }
 
 /* For autofs direct mounts the follow link triggers the mount */
@@ -533,9 +555,9 @@ static struct dentry *autofs4_lookup_unhashed(struct autofs_sb_info *sbi, struct
                         goto next;
 
                 if (d_unhashed(dentry)) {
-                        struct autofs_info *ino = autofs4_dentry_ino(dentry);
                         struct inode *inode = dentry->d_inode;
 
+                        ino = autofs4_dentry_ino(dentry);
                         list_del_init(&ino->rehash);
                         dget(dentry);
                         /*