All the error handling bugs I hit so far are all -ENOSPC from either:
- cow_file_range()
- run_delalloc_nocow()
- submit_uncompressed_range()
Previously when those functions failed, there was no error message at
all, making the debugging much harder.
So here we introduce extra error messages for:
- cow_file_range()
- run_delalloc_nocow()
- submit_uncompressed_range()
- writepage_delalloc() when btrfs_run_delalloc_range() failed
- extent_writepage() when extent_writepage_io() failed
One example of the new debug error messages is the following one:
run fstests generic/750 at 2024-12-08 12:41:41
BTRFS: device fsid 461b25f5-e240-4543-8deb-e7c2bd01a6d3 devid 1 transid 8 /dev/mapper/test-scratch1 (253:4) scanned by mount (2436600)
BTRFS info (device dm-4): first mount of filesystem 461b25f5-e240-4543-8deb-e7c2bd01a6d3
BTRFS info (device dm-4): using crc32c (crc32c-arm64) checksum algorithm
BTRFS info (device dm-4): forcing free space tree for sector size 4096 with page size 65536
BTRFS info (device dm-4): using free-space-tree
BTRFS warning (device dm-4): read-write for sector size 4096 with page size 65536 is experimental
BTRFS info (device dm-4): checking UUID tree
BTRFS error (device dm-4): cow_file_range failed, root=363 inode=412 start=503808 len=98304: -28
BTRFS error (device dm-4): run_delalloc_nocow failed, root=363 inode=412 start=503808 len=98304: -28
BTRFS error (device dm-4): failed to run delalloc range, root=363 ino=412 folio=458752 submit_bitmap=11-15 start=503808 len=98304: -28
Which shows an error from cow_file_range() which is called inside a
nocow write attempt, along with the extra bitmap from
writepage_delalloc().
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
975a6a8855