From 232ec8720d4e45405e37144c67053042c6b886d3 Mon Sep 17 00:00:00 2001 From: Lukas Czerner Date: Sun, 10 Mar 2013 22:46:30 -0400 Subject: [PATCH] ext4: update reserved space after the 'correction' Currently in ext4_ext_map_blocks() in delayed allocation writeback we would update the reservation and after that check whether we claimed cluster outside of the range of the allocation and if so, we'll give the block back to the reservation pool. However this also means that if the number of reserved data block dropped to zero before the correction, we would release all the metadata reservation as well, however we might still need it because the we're not done with the delayed allocation and there might be more blocks to come. This will result in error messages such as: EXT4-fs warning (device sdb): ext4_da_update_reserve_space:361: ino 12, allocated 1 with only 0 reserved metadata blocks (releasing 1 blocks with reserved 1 data blocks) This will only happen on bigalloc file system and it can be easily reproduced using fiemap-tester from xfstests like this: ./src/fiemap-tester -m DHDHDHDHD -S -p0 /mnt/test/file Or using xfstests such as 225. Fix this by doing the correction first and updating the reservation after that so that we do not accidentally decrease i_reserved_data_blocks to zero. Signed-off-by: Lukas Czerner Signed-off-by: "Theodore Ts'o" --- fs/ext4/extents.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 69df02ff96aa..bd69e906bd91 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4165,9 +4165,6 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, } } else { BUG_ON(allocated_clusters < reserved_clusters); - /* We will claim quota for all newly allocated blocks.*/ - ext4_da_update_reserve_space(inode, allocated_clusters, - 1); if (reserved_clusters < allocated_clusters) { struct ext4_inode_info *ei = EXT4_I(inode); int reservation = allocated_clusters - @@ -4218,6 +4215,15 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, ei->i_reserved_data_blocks += reservation; spin_unlock(&ei->i_block_reservation_lock); } + /* + * We will claim quota for all newly allocated blocks. + * We're updating the reserved space *after* the + * correction above so we do not accidentally free + * all the metadata reservation because we might + * actually need it later on. + */ + ext4_da_update_reserve_space(inode, allocated_clusters, + 1); } } -- GitLab