Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel…

…/git/mason/btrfs-unstable

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (39 commits)
  Btrfs: deal with errors from updating the tree log
  Btrfs: allow subvol deletion by unprivileged user with -o user_subvol_rm_allowed
  Btrfs: make SNAP_DESTROY async
  Btrfs: add SNAP_CREATE_ASYNC ioctl
  Btrfs: add START_SYNC, WAIT_SYNC ioctls
  Btrfs: async transaction commit
  Btrfs: fix deadlock in btrfs_commit_transaction
  Btrfs: fix lockdep warning on clone ioctl
  Btrfs: fix clone ioctl where range is adjacent to extent
  Btrfs: fix delalloc checks in clone ioctl
  Btrfs: drop unused variable in block_alloc_rsv
  Btrfs: cleanup warnings from gcc 4.6 (nonbugs)
  Btrfs: Fix variables set but not read (bugs found by gcc 4.6)
  Btrfs: Use ERR_CAST helpers
  Btrfs: use memdup_user helpers
  Btrfs: fix raid code for removing missing drives
  Btrfs: Switch the extent buffer rbtree into a radix tree
  Btrfs: restructure try_release_extent_buffer()
  Btrfs: use the flusher threads for delalloc throttling
  Btrfs: tune the chunk allocation to 5% of the FS as metadata
  ...

Fix up trivial conflicts in fs/btrfs/super.c and fs/fs-writeback.c, and
remove use of INIT_RCU_HEAD in fs/btrfs/extent_io.c (that init macro was
useless and removed in commit 5e8067a: "rcu head remove init")

fs/btrfs/compression.c

@@ -163,7 +163,6 @@ static int check_compressed_csum(struct inode *inode,
  */
 static void end_compressed_bio_read(struct bio *bio, int err)
 {
-	struct extent_io_tree *tree;
 	struct compressed_bio *cb = bio->bi_private;
 	struct inode *inode;
 	struct page *page;
@@ -187,7 +186,6 @@ static void end_compressed_bio_read(struct bio *bio, int err)
 	/* ok, we're the last bio for this extent, lets start
 	 * the decompression.
 	 */
-	tree = &BTRFS_I(inode)->io_tree;
 	ret = btrfs_zlib_decompress_biovec(cb->compressed_pages,
 					cb->start,
 					cb->orig_bio->bi_io_vec,

fs/btrfs/ctree.c

@@ -200,7 +200,6 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans,
 		      struct extent_buffer **cow_ret, u64 new_root_objectid)
 {
 	struct extent_buffer *cow;
-	u32 nritems;
 	int ret = 0;
 	int level;
 	struct btrfs_disk_key disk_key;
@@ -210,7 +209,6 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans,
 	WARN_ON(root->ref_cows && trans->transid != root->last_trans);
 
 	level = btrfs_header_level(buf);
-	nritems = btrfs_header_nritems(buf);
 	if (level == 0)
 		btrfs_item_key(buf, &disk_key, 0);
 	else
@@ -1008,7 +1006,6 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 	int wret;
 	int pslot;
 	int orig_slot = path->slots[level];
-	int err_on_enospc = 0;
 	u64 orig_ptr;
 
 	if (level == 0)
@@ -1071,8 +1068,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 	    BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
 		return 0;
 
-	if (btrfs_header_nritems(mid) < 2)
-		err_on_enospc = 1;
+	btrfs_header_nritems(mid);
 
 	left = read_node_slot(root, parent, pslot - 1);
 	if (left) {
@@ -1103,8 +1099,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 		wret = push_node_left(trans, root, left, mid, 1);
 		if (wret < 0)
 			ret = wret;
-		if (btrfs_header_nritems(mid) < 2)
-			err_on_enospc = 1;
+		btrfs_header_nritems(mid);
 	}
 
 	/*
@@ -1224,14 +1219,12 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
 	int wret;
 	int pslot;
 	int orig_slot = path->slots[level];
-	u64 orig_ptr;
 
 	if (level == 0)
 		return 1;
 
 	mid = path->nodes[level];
 	WARN_ON(btrfs_header_generation(mid) != trans->transid);
-	orig_ptr = btrfs_node_blockptr(mid, orig_slot);
 
 	if (level < BTRFS_MAX_LEVEL - 1)
 		parent = path->nodes[level + 1];
@@ -1577,13 +1570,33 @@ read_block_for_search(struct btrfs_trans_handle *trans,
 	blocksize = btrfs_level_size(root, level - 1);
 
 	tmp = btrfs_find_tree_block(root, blocknr, blocksize);
-	if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
-		/*
-		 * we found an up to date block without sleeping, return
-		 * right away
-		 */
-		*eb_ret = tmp;
-		return 0;
+	if (tmp) {
+		if (btrfs_buffer_uptodate(tmp, 0)) {
+			if (btrfs_buffer_uptodate(tmp, gen)) {
+				/*
+				 * we found an up to date block without
+				 * sleeping, return
+				 * right away
+				 */
+				*eb_ret = tmp;
+				return 0;
+			}
+			/* the pages were up to date, but we failed
+			 * the generation number check.  Do a full
+			 * read for the generation number that is correct.
+			 * We must do this without dropping locks so
+			 * we can trust our generation number
+			 */
+			free_extent_buffer(tmp);
+			tmp = read_tree_block(root, blocknr, blocksize, gen);
+			if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
+				*eb_ret = tmp;
+				return 0;
+			}
+			free_extent_buffer(tmp);
+			btrfs_release_path(NULL, p);
+			return -EIO;
+		}
 	}
 
 	/*
@@ -1596,8 +1609,7 @@ read_block_for_search(struct btrfs_trans_handle *trans,
 	btrfs_unlock_up_safe(p, level + 1);
 	btrfs_set_path_blocking(p);
 
-	if (tmp)
-		free_extent_buffer(tmp);
+	free_extent_buffer(tmp);
 	if (p->reada)
 		reada_for_search(root, p, level, slot, key->objectid);
 
@@ -2548,7 +2560,6 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
 {
 	struct btrfs_disk_key disk_key;
 	struct extent_buffer *right = path->nodes[0];
-	int slot;
 	int i;
 	int push_space = 0;
 	int push_items = 0;
@@ -2560,8 +2571,6 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
 	u32 this_item_size;
 	u32 old_left_item_size;
 
-	slot = path->slots[1];
-
 	if (empty)
 		nr = min(right_nritems, max_slot);
 	else
@@ -3330,7 +3339,6 @@ int btrfs_truncate_item(struct btrfs_trans_handle *trans,
 {
 	int ret = 0;
 	int slot;
-	int slot_orig;
 	struct extent_buffer *leaf;
 	struct btrfs_item *item;
 	u32 nritems;
@@ -3340,7 +3348,6 @@ int btrfs_truncate_item(struct btrfs_trans_handle *trans,
 	unsigned int size_diff;
 	int i;
 
-	slot_orig = path->slots[0];
 	leaf = path->nodes[0];
 	slot = path->slots[0];
 
@@ -3445,7 +3452,6 @@ int btrfs_extend_item(struct btrfs_trans_handle *trans,
 {
 	int ret = 0;
 	int slot;
-	int slot_orig;
 	struct extent_buffer *leaf;
 	struct btrfs_item *item;
 	u32 nritems;
@@ -3454,7 +3460,6 @@ int btrfs_extend_item(struct btrfs_trans_handle *trans,
 	unsigned int old_size;
 	int i;
 
-	slot_orig = path->slots[0];
 	leaf = path->nodes[0];
 
 	nritems = btrfs_header_nritems(leaf);
@@ -3787,7 +3792,6 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
 			    struct btrfs_key *cpu_key, u32 *data_size,
 			    int nr)
 {
-	struct extent_buffer *leaf;
 	int ret = 0;
 	int slot;
 	int i;
@@ -3804,7 +3808,6 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
 	if (ret < 0)
 		goto out;
 
-	leaf = path->nodes[0];
 	slot = path->slots[0];
 	BUG_ON(slot < 0);