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

[~andy/linux] / fs / autofs4 / root.c

diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index a54a946a50ae55bc44f04142565834527f07d524..edf5b6bddb528a43bb85e51eb834ecbdb14a7877 100644 (file)
--- 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);
                        /*