kernel/linux.git/fs/btrfs/ordered-data.h, branch v6.1.178

btrfs: fix false IO failure after falling back to buffered write

2026-07-24T13:55:17+00:00

[ Upstream commit 66ff4d366e7eb4d31813d2acabf3af512ce03aa5 ] [BUG] The test case generic/362 will fail with "nodatasum" mount option (*): MOUNT_OPTIONS -- -o nodatasum /dev/mapper/test-scratch1 /mnt/scratch # generic/362 0s ... - output mismatch (see /home/adam/xfstests/results//generic/362.out.bad) # --- tests/generic/362.out 2024-08-24 15:31:37.200000000 +0930 # +++ /home/adam/xfstests/results//generic/362.out.bad 2026-05-27 10:21:17.574771567 +0930 # @@ -1,2 +1,3 @@ # QA output created by 362 # +First write failed: Input/output error # Silence is golden # ... *: If the test case has been executed before with default data checksum, the failure will not reproduce. Need the following fix to make it reliably reproducible: https://lore.kernel.org/linux-btrfs/20260528111659.87113-1-wqu@suse.com/ [CAUSE] Inside __iomap_dio_rw(), the -EFAULT/-ENOTBLK error is not directly returned. Thus we never got an error pointer from __iomap_dio_rw(). The call chain looks like this: btrfs_direct_write() |- btrfs_dio_write() |- __iomap_dio_rw() | |- iomap_iter() | | |- btrfs_dio_iomap_begin() | | Now an ordered extent is allocated for the 4K write. | | | |- iomi.status = iomap_dio_iter() | | Where iomap_dio_iter() returned -EFAULT. | | | |- ret = iomap_iter() | | |- btrfs_dio_iomap_end() | | | |- btrfs_finish_ordered_extent(uptodate = false) | | | | |- can_finish_ordered_extent() | | | | |- btrfs_mark_ordered_extent_error() | | | | |- mapping_set_error() | | | | Now the address space is marked error. | | | | return -ENOTBLK | | |- return -ENOTBLK | |- if (ret == -ENOTBLK) { ret = 0; } | Now the return value is reset to 0. | Thus no error pointer will be returned. | |- ret = iomap_dio_complete() | Since no byte is submitted, @ret is 0. | |- Fallback to buffered IO | And the buffered write finished without error | |- filemap_fdatawait_range() |- filemap_check_errors() The previous error is recorded, thus an error is returned However the buffered write is properly submitted and finished, the error is from the btrfs_finish_ordered_extent() call with @uptodate = false. [FIX] When a short dio write happened, any range that is submitted will have btrfs_extract_ordered_extent() to be called, thus the submitted range will always have an OE just covering the submitted range. The remaining OE range is never submitted, thus they should be treated as truncated, not an error. So that we can properly reclaim and not insert an unnecessary file extent item, without marking the mapping as error. Extract a helper, btrfs_mark_ordered_extent_truncated(), and utilize that helper to mark the direct IO ordered extent as truncated, so it won't cause failure for the later buffered fallback. [REASON FOR NO FIXES TAG] The bug itself is pretty old, at commit f85781fb505e ("btrfs: switch to iomap for direct IO") we're already passing @uptodate=false finishing the OE. But at that time OE with IOERR won't call mapping_set_error(), so it's not exposed. Later commit d61bec08b904 ("btrfs: mark ordered extent and inode with error if we fail to finish") finally exposed the bug, but that commit is doing a correct job, not the root cause. Anyway the bug is very old, dating back to 5.1x days, thus only CC to stable. CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Boris Burkov Signed-off-by: Qu Wenruo Signed-off-by: David Sterba Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

btrfs: mark the len field in struct btrfs_ordered_sum as unsigned

2024-01-10T16:10:35+00:00

[ Upstream commit 6e4b2479ab38b3f949a85964da212295d32102f0 ] len can't ever be negative, so mark it as an u32 instead of int. Reviewed-by: Johannes Thumshirn Signed-off-by: Christoph Hellwig Reviewed-by: David Sterba Signed-off-by: David Sterba Stable-dep-of: 9e65bfca24cf ("btrfs: fix qgroup_free_reserved_data int overflow") Signed-off-by: Sasha Levin

btrfs: add btrfs_try_lock_ordered_range

2022-09-29T15:08:28+00:00

For IOCB_NOWAIT we're going to want to use try lock on the extent lock, and simply bail if there's an ordered extent in the range because the only choice there is to wait for the ordered extent to complete. Reviewed-by: Filipe Manana Signed-off-by: Josef Bacik Signed-off-by: Stefan Roesch Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: move btrfs_ordered_sum_size into file-item.c

2022-09-26T10:28:06+00:00

This is defined in ordered-data.h, but is only used in file-item.c. Move this to file-item.c as it doesn't need to be global. Reviewed-by: Johannes Thumshirn Reviewed-by: Anand Jain Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: remove the finish_func argument to btrfs_mark_ordered_io_finished

2022-07-25T15:45:37+00:00

finish_func is always set to finish_ordered_fn, so remove it and also the now pointless and somewhat confusingly named __endio_write_update_ordered wrapper. Reviewed-by: Nikolay Borisov Signed-off-by: Christoph Hellwig Signed-off-by: David Sterba

btrfs: add BTRFS_IOC_ENCODED_WRITE

2022-03-14T12:13:51+00:00

The implementation resembles direct I/O: we have to flush any ordered extents, invalidate the page cache, and do the io tree/delalloc/extent map/ordered extent dance. From there, we can reuse the compression code with a minor modification to distinguish the write from writeback. This also creates inline extents when possible. Signed-off-by: Omar Sandoval Signed-off-by: David Sterba

btrfs: add ram_bytes and offset to btrfs_ordered_extent

2022-03-14T12:13:51+00:00

Currently, we only create ordered extents when ram_bytes == num_bytes and offset == 0. However, BTRFS_IOC_ENCODED_WRITE writes may create extents which only refer to a subset of the full unencoded extent, so we need to plumb these fields through the ordered extent infrastructure and pass them down to insert_reserved_file_extent(). Since we're changing the btrfs_add_ordered_extent* signature, let's get rid of the trivial wrappers and add a kernel-doc. Reviewed-by: Nikolay Borisov Reviewed-by: Josef Bacik Signed-off-by: Omar Sandoval Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: remove uptodate parameter from btrfs_dec_test_first_ordered_pending

2021-08-23T11:19:02+00:00

In commit e65f152e4348 ("btrfs: refactor how we finish ordered extent io for endio functions") there was last caller not using 1 for the uptodate parameter. Now there's only one, passing 1, so we can remove it and simplify the code. Reviewed-by: Qu Wenruo Signed-off-by: David Sterba

btrfs: store a block_device in struct btrfs_ordered_extent

2021-07-22T13:50:15+00:00

Store the block device instead of the gendisk in the btrfs_ordered_extent structure instead of acquiring a reference to it later. Note: this is from series removing bdgrab/bdput, btrfs is one of the last users. Signed-off-by: Christoph Hellwig Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: introduce btrfs_lookup_first_ordered_range()

2021-06-21T13:19:08+00:00

Although we already have btrfs_lookup_first_ordered_extent() and btrfs_lookup_ordered_extent(), they all have their own limitations: - btrfs_lookup_ordered_extent() can't do extra range check It's only designed to lookup any ordered extent before certain bytenr. - btrfs_lookup_first_ordered_extent() may not return the first ordered extent in the range It doesn't ensure the first ordered extent is returned. The existing callers are only interested in exhausting all ordered extents in a range, the order is not important. For incoming btrfs_invalidatepage() refactoring, we need a way to properly iterate all ordered extents in their bytenr order of a range. So this patch will introduce a new function, btrfs_lookup_first_ordered_range(), to do ordered extent with bytenr order awareness and extra range check. Signed-off-by: Qu Wenruo Signed-off-by: David Sterba