Merge tag 'regmap-3.4' into regmap-stride

regmap: Last minute bug fix for 3.4

This is a last minute bug fix that was only just noticed since the code
path that's being exercised here is one that is fairly rarely used.  The
changelog for the change itself is extremely clear and the code itself
is obvious to inspection so should be pretty safe.

Conflicts:
	drivers/base/regmap/regmap.c (overlap between the fix and stride code)

1 files changed, 18 insertions, 36 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 115bc05e42b..61b16c641ce 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1947,7 +1947,7 @@ static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
  * extent_io.c will try to find good copies for us.
  */
 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
-			       struct extent_state *state)
+			       struct extent_state *state, int mirror)
 {
 	size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
 	struct inode *inode = page->mapping->host;
@@ -4069,7 +4069,7 @@ static struct inode *new_simple_dir(struct super_block *s,
 	BTRFS_I(inode)->dummy_inode = 1;
 
 	inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
-	inode->i_op = &simple_dir_inode_operations;
+	inode->i_op = &btrfs_dir_ro_inode_operations;
 	inode->i_fop = &simple_dir_operations;
 	inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
 	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
@@ -4140,14 +4140,18 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
 static int btrfs_dentry_delete(const struct dentry *dentry)
 {
 	struct btrfs_root *root;
+	struct inode *inode = dentry->d_inode;
 
-	if (!dentry->d_inode && !IS_ROOT(dentry))
-		dentry = dentry->d_parent;
+	if (!inode && !IS_ROOT(dentry))
+		inode = dentry->d_parent->d_inode;
 
-	if (dentry->d_inode) {
-		root = BTRFS_I(dentry->d_inode)->root;
+	if (inode) {
+		root = BTRFS_I(inode)->root;
 		if (btrfs_root_refs(&root->root_item) == 0)
 			return 1;
+
+		if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
+			return 1;
 	}
 	return 0;
 }
@@ -4188,7 +4192,6 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
 	struct btrfs_path *path;
 	struct list_head ins_list;
 	struct list_head del_list;
-	struct qstr q;
 	int ret;
 	struct extent_buffer *leaf;
 	int slot;
@@ -4279,7 +4282,6 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
 
 		while (di_cur < di_total) {
 			struct btrfs_key location;
-			struct dentry *tmp;
 
 			if (verify_dir_item(root, leaf, di))
 				break;
@@ -4300,35 +4302,15 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
 			d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
 			btrfs_dir_item_key_to_cpu(leaf, di, &location);
 
-			q.name = name_ptr;
-			q.len = name_len;
-			q.hash = full_name_hash(q.name, q.len);
-			tmp = d_lookup(filp->f_dentry, &q);
-			if (!tmp) {
-				struct btrfs_key *newkey;
-
-				newkey = kzalloc(sizeof(struct btrfs_key),
-						 GFP_NOFS);
-				if (!newkey)
-					goto no_dentry;
-				tmp = d_alloc(filp->f_dentry, &q);
-				if (!tmp) {
-					kfree(newkey);
-					dput(tmp);
-					goto no_dentry;
-				}
-				memcpy(newkey, &location,
-				       sizeof(struct btrfs_key));
-				tmp->d_fsdata = newkey;
-				tmp->d_flags |= DCACHE_NEED_LOOKUP;
-				d_rehash(tmp);
-				dput(tmp);
-			} else {
-				dput(tmp);
-			}
-no_dentry:
+
 			/* is this a reference to our own snapshot? If so
-			 * skip it
+			 * skip it.
+			 *
+			 * In contrast to old kernels, we insert the snapshot's
+			 * dir item and dir index after it has been created, so
+			 * we won't find a reference to our own snapshot. We
+			 * still keep the following code for backward
+			 * compatibility.
 			 */
 			if (location.type == BTRFS_ROOT_ITEM_KEY &&
 			    location.objectid == root->root_key.objectid) {