[ Upstream commit 8e4e5cdf2fdeb99445a468b6b6436ad79b9ecb30 ]
Factor out a new common helper ext4_map_query_blocks() from the
ext4_da_map_blocks(), it query and return the extent map status on the
inode's extent path, no logic changes.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://patch.msgid.link/20240517124005.347221-2-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 0ea6560abb3b ("ext4: check the extent status again before inserting delalloc block")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit acf795dc161f3cf481db20f05db4250714e375e5 ]
ext4_da_map_blocks() only hold i_data_sem in shared mode and i_rwsem
when inserting delalloc extents, it could be raced by another querying
path of ext4_map_blocks() without i_rwsem, .e.g buffered read path.
Suppose we buffered read a file containing just a hole, and without any
cached extents tree, then it is raced by another delayed buffered write
to the same area or the near area belongs to the same hole, and the new
delalloc extent could be overwritten to a hole extent.
pread() pwrite()
filemap_read_folio()
ext4_mpage_readpages()
ext4_map_blocks()
down_read(i_data_sem)
ext4_ext_determine_hole()
//find hole
ext4_ext_put_gap_in_cache()
ext4_es_find_extent_range()
//no delalloc extent
ext4_da_map_blocks()
down_read(i_data_sem)
ext4_insert_delayed_block()
//insert delalloc extent
ext4_es_insert_extent()
//overwrite delalloc extent to hole
This race could lead to inconsistent delalloc extents tree and
incorrect reserved space counter. Fix this by converting to hold
i_data_sem in exclusive mode when adding a new delalloc extent in
ext4_da_map_blocks().
Cc: stable@vger.kernel.org
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20240127015825.1608160-3-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6c120399cde6b1b5cf65ce403765c579fb3d3e50 ]
Now ext4_es_insert_extent() never return error, so make it return void.
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230424033846.4732-12-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: acf795dc161f ("ext4: convert to exclusive lock while inserting delalloc extents")
Signed-off-by: Sasha Levin <sashal@kernel.org>
