btrfs: clean_tree_block should panic on observed memory corruption and return void

 The only error condition in clean_tree_block is an accounting bug.
 Returning without modifying dirty_metadata_bytes and as if the cleaning
 as been performed may cause problems later so it should panic instead.

 It should probably be a BUG_ON but we have btrfs_panic now.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 534266fe505f25cf4a89e25036ff7994cb8c28d5..d52ec1155204c6024c699c427c9b2971e8d402b4 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1109,8 +1109,8 @@ struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 
 }
 
-int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-                    struct extent_buffer *buf)
+void clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+                     struct extent_buffer *buf)
 {
        struct inode *btree_inode = root->fs_info->btree_inode;
        if (btrfs_header_generation(buf) ==
@@ -1121,8 +1121,14 @@ int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                        spin_lock(&root->fs_info->delalloc_lock);
                        if (root->fs_info->dirty_metadata_bytes >= buf->len)
                                root->fs_info->dirty_metadata_bytes -= buf->len;
-                       else
-                               WARN_ON(1);
+                       else {
+                               spin_unlock(&root->fs_info->delalloc_lock);
+                               btrfs_panic(root->fs_info, -EOVERFLOW,
+                                         "Can't clear %lu bytes from "
+                                         " dirty_mdatadata_bytes (%lu)",
+                                         buf->len,
+                                         root->fs_info->dirty_metadata_bytes);
+                       }
                        spin_unlock(&root->fs_info->delalloc_lock);
                }
 
@@ -1131,7 +1137,6 @@ int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
                                          buf);
        }
-       return 0;
 }
 
 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,

diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index e4bc4741319bd3a1e094de03566feeb360d35e4d..ca34237ae384377a17bc942eb159c25abff6299b 100644 (file)
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -44,8 +44,8 @@ int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr, u32 blocksize,
                         int mirror_num, struct extent_buffer **eb);
 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
                                                   u64 bytenr, u32 blocksize);
-int clean_tree_block(struct btrfs_trans_handle *trans,
-                    struct btrfs_root *root, struct extent_buffer *buf);
+void clean_tree_block(struct btrfs_trans_handle *trans,
+                     struct btrfs_root *root, struct extent_buffer *buf);
 int open_ctree(struct super_block *sb,
               struct btrfs_fs_devices *fs_devices,
               char *options);