kernel/linux.git/fs/btrfs/ordered-data.c, branch v5.15.209

btrfs: zoned: fix double counting of split ordered extent

2021-09-07T12:30:41+00:00

btrfs_add_ordered_extent_*() add num_bytes to fs_info->ordered_bytes. Then, splitting an ordered extent will call btrfs_add_ordered_extent_*() again for split extents, leading to double counting of the region of a split extent. These leaked bytes are finally reported at unmount time as follow: BTRFS info (device dm-1): at unmount dio bytes count 364544 Fix the double counting by subtracting split extent's size from fs_info->ordered_bytes. Fixes: d22002fd37bd ("btrfs: zoned: split ordered extent when bio is sent") CC: stable@vger.kernel.org # 5.12+ Reviewed-by: Johannes Thumshirn Signed-off-by: Naohiro Aota 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: make page Ordered bit to be subpage compatible

2021-06-21T13:19:10+00:00

This involves the following modification: - Ordered extent creation This is done in process_one_page(), now PAGE_SET_ORDERED will call subpage helper to do the work. - endio functions This is done in btrfs_mark_ordered_io_finished(). - btrfs_invalidatepage() - btrfs_cleanup_ordered_extents() Use the subpage page helper, and add an extra branch to exit if the locked page have covered the full range. Now the usage of page Ordered flag for ordered extent accounting is fully subpage compatible. Tested-by: Ritesh Harjani # [ppc64] Tested-by: Anand Jain # [aarch64] Signed-off-by: Qu Wenruo Signed-off-by: David Sterba

btrfs: rename PagePrivate2 to PageOrdered inside btrfs

2021-06-21T13:19:09+00:00

Inside btrfs we use Private2 page status to indicate we have an ordered extent with pending IO for the sector. But the page status name, Private2, tells us nothing about the bit itself, so this patch will rename it to Ordered. And with extra comment about the bit added, so reader who is still uncertain about the page Ordered status, will find the comment pretty easily. Reviewed-by: Josef Bacik Signed-off-by: Qu Wenruo 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

btrfs: refactor how we finish ordered extent io for endio functions

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

Btrfs has two endio functions to mark certain io range finished for ordered extents: - __endio_write_update_ordered() This is for direct IO - btrfs_writepage_endio_finish_ordered() This for buffered IO. However they go different routines to handle ordered extent io: - Whether to iterate through all ordered extents __endio_write_update_ordered() will but btrfs_writepage_endio_finish_ordered() will not. In fact, iterating through all ordered extents will benefit later subpage support, while for current PAGE_SIZE == sectorsize requirement this behavior makes no difference. - Whether to update page Private2 flag __endio_write_update_ordered() will not update page Private2 flag as for iomap direct IO, the page can not be even mapped. While btrfs_writepage_endio_finish_ordered() will clear Private2 to prevent double accounting against btrfs_invalidatepage(). Those differences are pretty subtle, and the ordered extent iterations code in callers makes code much harder to read. So this patch will introduce a new function, btrfs_mark_ordered_io_finished(), to do the heavy lifting: - Iterate through all ordered extents in the range - Do the ordered extent accounting - Queue the work for finished ordered extent This function has two new feature: - Proper underflow detection and recovery The old underflow detection will only detect the problem, then continue. No proper info like root/inode/ordered extent info, nor noisy enough to be caught by fstests. Furthermore when underflow happens, the ordered extent will never finish. New error detection will reset the bytes_left to 0, do proper kernel warning, and output extra info including root, ino, ordered extent range, the underflow value. - Prevent double accounting based on Private2 flag Now if we find a range without Private2 flag, we will skip to next range. As that means someone else has already finished the accounting of ordered extent. This makes no difference for current code, but will be a critical part for incoming subpage support, as we can call btrfs_mark_ordered_io_finished() for multiple sectors if they are beyond inode size. Thus such double accounting prevention is a key feature for subpage. Now both endio functions only need to call that new function. And since the only caller of btrfs_dec_test_first_ordered_pending() is removed, also remove btrfs_dec_test_first_ordered_pending() completely. Signed-off-by: Qu Wenruo Signed-off-by: David Sterba

btrfs: zoned: fix silent data loss after failure splitting ordered extent

2021-04-28T18:09:38+00:00

On a zoned filesystem, sometimes we need to split an ordered extent into 3 different ordered extents. The original ordered extent is shortened, at the front and at the rear, and we create two other new ordered extents to represent the trimmed parts of the original ordered extent. After adjusting the original ordered extent, we create an ordered extent to represent the pre-range, and that may fail with ENOMEM for example. After that we always try to create the ordered extent for the post-range, and if that happens to succeed we end up returning success to the caller as we overwrite the 'ret' variable which contained the previous error. This means we end up with a file range for which there is no ordered extent, which results in the range never getting a new file extent item pointing to the new data location. And since the split operation did not return an error, writeback does not fail and the inode's mapping is not flagged with an error, resulting in a subsequent fsync not reporting an error either. It's possibly very unlikely to have the creation of the post-range ordered extent succeed after the creation of the pre-range ordered extent failed, but it's not impossible. So fix this by making sure we only create the post-range ordered extent if there was no error creating the ordered extent for the pre-range. Fixes: d22002fd37bd97 ("btrfs: zoned: split ordered extent when bio is sent") CC: stable@vger.kernel.org # 5.12+ Signed-off-by: Filipe Manana Signed-off-by: David Sterba

btrfs: replace offset_in_entry with in_range

2021-04-19T15:25:14+00:00

No point in duplicating the functionality just use the generic helper that has the same semantics. Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: zoned: use ZONE_APPEND write for zoned mode

2021-02-09T01:46:06+00:00

Enable zone append writing for zoned mode. When using zone append, a bio is issued to the start of a target zone and the device decides to place it inside the zone. Upon completion the device reports the actual written position back to the host. Three parts are necessary to enable zone append mode. First, modify the bio to use REQ_OP_ZONE_APPEND in btrfs_submit_bio_hook() and adjust the bi_sector to point the beginning of the zone. Second, record the returned physical address (and disk/partno) to the ordered extent in end_bio_extent_writepage() after the bio has been completed. We cannot resolve the physical address to the logical address because we can neither take locks nor allocate a buffer in this end_bio context. So, we need to record the physical address to resolve it later in btrfs_finish_ordered_io(). And finally, rewrite the logical addresses of the extent mapping and checksum data according to the physical address using btrfs_rmap_block. If the returned address matches the originally allocated address, we can skip this rewriting process. Reviewed-by: Josef Bacik Signed-off-by: Johannes Thumshirn Signed-off-by: Naohiro Aota Reviewed-by: David Sterba Signed-off-by: David Sterba