From ba38eb4de354d228f2792f93cde2c748a3a3f3b2 Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Thu, 10 Nov 2011 20:45:04 -0500 Subject: [PATCH] Btrfs: fix no reserved space for writing out inode cache I-node cache forgets to reserve the space when writing out it. And when we do some stress test, such as synctest, it will trigger WARN_ON() in use_block_rsv(). WARNING: at fs/btrfs/extent-tree.c:5718 btrfs_alloc_free_block+0xbf/0x281 [btrfs]() ... Call Trace: [] warn_slowpath_common+0x80/0x98 [] warn_slowpath_null+0x15/0x17 [] btrfs_alloc_free_block+0xbf/0x281 [btrfs] [] ? __set_page_dirty_nobuffers+0xfe/0x108 [] __btrfs_cow_block+0x118/0x3b5 [btrfs] [] btrfs_cow_block+0x103/0x14e [btrfs] [] btrfs_search_slot+0x249/0x6a4 [btrfs] [] btrfs_lookup_inode+0x2a/0x8a [btrfs] [] btrfs_update_inode+0xaa/0x141 [btrfs] [] btrfs_save_ino_cache+0xea/0x202 [btrfs] [] ? btrfs_update_reloc_root+0x17e/0x197 [btrfs] [] commit_fs_roots+0xaa/0x158 [btrfs] [] btrfs_commit_transaction+0x405/0x731 [btrfs] [] ? wake_up_bit+0x25/0x25 [] ? btrfs_log_dentry_safe+0x43/0x51 [btrfs] [] btrfs_sync_file+0x16a/0x198 [btrfs] [] ? mntput+0x21/0x23 [] vfs_fsync_range+0x18/0x21 [] vfs_fsync+0x17/0x19 [] do_fsync+0x29/0x3e [] sys_fsync+0xb/0xf [] system_call_fastpath+0x16/0x1b Sometimes it causes BUG_ON() in the reservation code of the delayed inode is triggered. So we must reserve enough space for inode cache. Note: If we can not reserve the enough space for inode cache, we will give up writing out it. Signed-off-by: Miao Xie Signed-off-by: Chris Mason --- fs/btrfs/inode-map.c | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c index 53dcbdf..f8962a9 100644 --- a/fs/btrfs/inode-map.c +++ b/fs/btrfs/inode-map.c @@ -398,6 +398,8 @@ int btrfs_save_ino_cache(struct btrfs_root *root, struct btrfs_free_space_ctl *ctl = root->free_ino_ctl; struct btrfs_path *path; struct inode *inode; + struct btrfs_block_rsv *rsv; + u64 num_bytes; u64 alloc_hint = 0; int ret; int prealloc; @@ -421,11 +423,26 @@ int btrfs_save_ino_cache(struct btrfs_root *root, if (!path) return -ENOMEM; + rsv = trans->block_rsv; + trans->block_rsv = &root->fs_info->trans_block_rsv; + + num_bytes = trans->bytes_reserved; + /* + * 1 item for inode item insertion if need + * 3 items for inode item update (in the worst case) + * 1 item for free space object + * 3 items for pre-allocation + */ + trans->bytes_reserved = btrfs_calc_trans_metadata_size(root, 8); + ret = btrfs_block_rsv_add_noflush(root, trans->block_rsv, + trans->bytes_reserved); + if (ret) + goto out; again: inode = lookup_free_ino_inode(root, path); if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) { ret = PTR_ERR(inode); - goto out; + goto out_release; } if (IS_ERR(inode)) { @@ -434,7 +451,7 @@ again: ret = create_free_ino_inode(root, trans, path); if (ret) - goto out; + goto out_release; goto again; } @@ -477,11 +494,14 @@ again: } btrfs_free_reserved_data_space(inode, prealloc); + ret = btrfs_write_out_ino_cache(root, trans, path); out_put: iput(inode); +out_release: + btrfs_block_rsv_release(root, trans->block_rsv, trans->bytes_reserved); out: - if (ret == 0) - ret = btrfs_write_out_ino_cache(root, trans, path); + trans->block_rsv = rsv; + trans->bytes_reserved = num_bytes; btrfs_free_path(path); return ret; -- 2.7.4