Btrfs: check return value of read_tree_block()

This patch is checking return value of read_tree_block(),
and if it is NULL, error processing.

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 4edcbe9..84d7ca1 100644 (file)
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -682,6 +682,8 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
                        if (!cur) {
                                cur = read_tree_block(root, blocknr,
                                                         blocksize, gen);
+                               if (!cur)
+                                       return -EIO;
                        } else if (!uptodate) {
                                btrfs_read_buffer(cur, gen);
                        }
@@ -4087,6 +4089,7 @@ find_next_key:
                }
                btrfs_set_path_blocking(path);
                cur = read_node_slot(root, cur, slot);
+               BUG_ON(!cur);
 
                btrfs_tree_lock(cur);
 

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a6a8159..5bc658a 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -6067,6 +6067,8 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
                if (reada && level == 1)
                        reada_walk_down(trans, root, wc, path);
                next = read_tree_block(root, bytenr, blocksize, generation);
+               if (!next)
+                       return -EIO;
                btrfs_tree_lock(next);
                btrfs_set_lock_blocking(next);
        }
@@ -7937,6 +7939,10 @@ static noinline int relocate_one_extent(struct btrfs_root *extent_root,
 
                        eb = read_tree_block(found_root, block_start,
                                             block_size, 0);
+                       if (!eb) {
+                               ret = -EIO;
+                               goto out;
+                       }
                        btrfs_tree_lock(eb);
                        BUG_ON(level != btrfs_header_level(eb));
 

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index c863c84..58250e0 100644 (file)
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -1724,6 +1724,7 @@ again:
 
                        eb = read_tree_block(dest, old_bytenr, blocksize,
                                             old_ptr_gen);
+                       BUG_ON(!eb);
                        btrfs_tree_lock(eb);
                        if (cow) {
                                ret = btrfs_cow_block(trans, dest, eb, parent,
@@ -2513,6 +2514,10 @@ static int do_relocation(struct btrfs_trans_handle *trans,
                blocksize = btrfs_level_size(root, node->level);
                generation = btrfs_node_ptr_generation(upper->eb, slot);
                eb = read_tree_block(root, bytenr, blocksize, generation);
+               if (!eb) {
+                       err = -EIO;
+                       goto next;
+               }
                btrfs_tree_lock(eb);
                btrfs_set_lock_blocking(eb);
 
@@ -2670,6 +2675,7 @@ static int get_tree_block_key(struct reloc_control *rc,
        BUG_ON(block->key_ready);
        eb = read_tree_block(rc->extent_root, block->bytenr,
                             block->key.objectid, block->key.offset);
+       BUG_ON(!eb);
        WARN_ON(btrfs_header_level(eb) != block->level);
        if (block->level == 0)
                btrfs_item_key_to_cpu(eb, &block->key, 0);