linux/fs/btrfs
Qu Wenruo bd8f7e6277 btrfs: only write the sectors in the vertical stripe which has data stripes
If we have only 8K partial write at the beginning of a full RAID56
stripe, we will write the following contents:

                    0  8K           32K             64K
Disk 1	(data):     |XX|            |               |
Disk 2  (data):     |               |               |
Disk 3  (parity):   |XXXXXXXXXXXXXXX|XXXXXXXXXXXXXXX|

|X| means the sector will be written back to disk.

Note that, although we won't write any sectors from disk 2, but we will
write the full 64KiB of parity to disk.

This behavior is fine for now, but not for the future (especially for
RAID56J, as we waste quite some space to journal the unused parity
stripes).

So here we will also utilize the btrfs_raid_bio::dbitmap, anytime we
queue a higher level bio into an rbio, we will update rbio::dbitmap to
indicate which vertical stripes we need to writeback.

And at finish_rmw(), we also check dbitmap to see if we need to write
any sector in the vertical stripe.

So after the patch, above example will only lead to the following
writeback pattern:

                    0  8K           32K             64K
Disk 1	(data):     |XX|            |               |
Disk 2  (data):     |               |               |
Disk 3  (parity):   |XX|            |               |

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:44:34 +02:00
..
tests Revert "btrfs: turn fs_info member buffer_radix into XArray" 2022-07-15 19:14:33 +02:00
acl.c btrfs: reserve correct number of items for inode creation 2022-05-16 17:03:08 +02:00
async-thread.c btrfs: simplify WQ_HIGHPRI handling in struct btrfs_workqueue 2022-05-16 17:03:15 +02:00
async-thread.h btrfs: simplify WQ_HIGHPRI handling in struct btrfs_workqueue 2022-05-16 17:03:15 +02:00
backref.c btrfs: unify the error handling pattern for read_tree_block() 2022-03-14 13:13:53 +01:00
backref.h
block-group.c btrfs: zoned: zone finish unused block group 2022-05-16 17:17:32 +02:00
block-group.h btrfs: zoned: prevent allocation from previous data relocation BG 2022-06-21 14:43:48 +02:00
block-rsv.c btrfs: reserve extra space for the free space tree 2022-01-07 14:18:25 +01:00
block-rsv.h btrfs: init root block_rsv at init root time 2022-01-03 15:09:48 +01:00
btrfs_inode.h btrfs: move struct btrfs_dio_private to inode.c 2022-05-16 17:17:32 +02:00
check-integrity.c btrfs: check-integrity: simplify bio allocation in btrfsic_read_block 2022-05-16 17:03:12 +02:00
check-integrity.h btrfs: check-integrity: split submit_bio from btrfsic checking 2022-05-16 17:03:12 +02:00
compression.c btrfs: introduce a data checksum checking helper 2022-07-25 17:44:33 +02:00
compression.h btrfs: derive compression type from extent map during reads 2022-05-16 17:17:31 +02:00
ctree.c btrfs: sink parameter is_data to btrfs_set_disk_extent_flags 2022-05-16 17:17:31 +02:00
ctree.h btrfs: factor out a btrfs_csum_ptr helper 2022-07-25 17:44:34 +02:00
delalloc-space.c btrfs: avoid blocking on space revervation when doing nowait dio writes 2022-05-16 17:03:10 +02:00
delalloc-space.h
delayed-inode.c Revert "btrfs: turn delayed_nodes_tree into an XArray" 2022-07-15 19:15:19 +02:00
delayed-inode.h
delayed-ref.c btrfs: remove btrfs_delayed_extent_op::is_data 2022-05-16 17:17:31 +02:00
delayed-ref.h btrfs: remove btrfs_delayed_extent_op::is_data 2022-05-16 17:17:31 +02:00
dev-replace.c btrfs: use a local variable for fs_devices pointer in btrfs_dev_replace_finishing 2022-05-16 17:03:08 +02:00
dev-replace.h
dir-item.c btrfs: use btrfs_for_each_slot in btrfs_search_dir_index_item 2022-05-16 17:03:07 +02:00
discard.c
discard.h
disk-io.c btrfs: fix typos in comments 2022-07-25 17:44:33 +02:00
disk-io.h btrfs: remove unused parameter bio_flags from btrfs_wq_submit_bio 2022-05-16 17:17:31 +02:00
export.c
export.h
extent-io-tree.h btrfs: Convert from invalidatepage to invalidate_folio 2022-03-15 08:23:29 -04:00
extent-tree.c for-5.19-rc7-tag 2022-07-16 13:48:55 -07:00
extent_io.c btrfs: refactor end_bio_extent_readpage code flow 2022-07-25 17:44:34 +02:00
extent_io.h Page cache changes for 5.19 2022-05-24 19:55:07 -07:00
extent_map.c btrfs: assert we have a write lock when removing and replacing extent maps 2022-03-14 13:13:50 +01:00
extent_map.h btrfs: defrag: don't use merged extent map for their generation check 2022-02-23 17:43:13 +01:00
file-item.c btrfs: handle csum lookup errors properly on reads 2022-03-14 13:13:51 +01:00
file.c for-5.19-rc3-tag 2022-06-26 10:11:36 -07:00
free-space-cache.c Page cache changes for 5.19 2022-05-24 19:55:07 -07:00
free-space-cache.h btrfs: change name and type of private member of btrfs_free_space_ctl 2022-01-03 15:09:50 +01:00
free-space-tree.c btrfs: use rbtree with leftmost node cached for tracking lowest block group 2022-05-16 17:03:13 +02:00
free-space-tree.h
inode-item.c btrfs: make should_throttle loop local in btrfs_truncate_inode_items 2022-01-07 14:18:25 +01:00
inode-item.h btrfs: add inode to truncate control 2022-01-07 14:18:24 +01:00
inode.c btrfs: use btrfs_bio_for_each_sector in btrfs_check_read_dio_bio 2022-07-25 17:44:34 +02:00
ioctl.c btrfs: use btrfs_try_lock_balance in btrfs_ioctl_balance 2022-07-25 17:44:34 +02:00
Kconfig btrfs: use generic Kconfig option for 256kB page size limit 2022-01-20 08:52:55 +02:00
locking.c btrfs: don't set lock_owner when locking extent buffer for reading 2022-06-21 14:46:56 +02:00
locking.h
lzo.c btrfs: add lzo workspace buffer length constants 2022-03-14 13:13:50 +01:00
Makefile Kbuild: add -Wno-shift-negative-value where -Wextra is used 2022-03-13 17:30:31 +09:00
misc.h
ordered-data.c btrfs: fix typos in comments 2022-07-25 17:44:33 +02:00
ordered-data.h btrfs: add BTRFS_IOC_ENCODED_WRITE 2022-03-14 13:13:51 +01:00
orphan.c
print-tree.c btrfs: unify the error handling pattern for read_tree_block() 2022-03-14 13:13:53 +01:00
print-tree.h
props.c btrfs: move common inode creation code into btrfs_create_new_inode() 2022-05-16 17:03:08 +02:00
props.h btrfs: move common inode creation code into btrfs_create_new_inode() 2022-05-16 17:03:08 +02:00
qgroup.c btrfs: avoid blocking on space revervation when doing nowait dio writes 2022-05-16 17:03:10 +02:00
qgroup.h btrfs: avoid blocking on space revervation when doing nowait dio writes 2022-05-16 17:03:10 +02:00
raid56.c btrfs: only write the sectors in the vertical stripe which has data stripes 2022-07-25 17:44:34 +02:00
raid56.h btrfs: raid56: make raid56_add_scrub_pages() subpage compatible 2022-05-16 17:03:15 +02:00
rcu-string.h
ref-verify.c btrfs: stop accessing ->extent_root directly 2022-01-03 15:09:49 +01:00
ref-verify.h
reflink.c btrfs: add missing inode updates on each iteration when replacing extents 2022-06-21 14:43:21 +02:00
reflink.h
relocation.c Page cache changes for 5.19 2022-05-24 19:55:07 -07:00
root-tree.c btrfs: avoid blocking on space revervation when doing nowait dio writes 2022-05-16 17:03:10 +02:00
scrub.c btrfs: use integrated bitmaps for scrub_parity::dbitmap and ebitmap 2022-07-25 17:44:34 +02:00
send.c for-5.19-rc7-tag 2022-07-16 13:48:55 -07:00
send.h btrfs: reuse existing inode from btrfs_ioctl 2022-03-14 13:13:46 +01:00
space-info.c btrfs: fix typos in comments 2022-07-25 17:44:33 +02:00
space-info.h btrfs: move definition of btrfs_raid_types to volumes.h 2022-05-16 17:03:16 +02:00
struct-funcs.c
subpage.c btrfs: fix typos in comments 2022-07-25 17:44:33 +02:00
subpage.h btrfs: make nodesize >= PAGE_SIZE case to reuse the non-subpage routine 2022-05-16 17:03:11 +02:00
super.c btrfs: fix typos in comments 2022-07-25 17:44:33 +02:00
sysfs.c btrfs: fix typos in comments 2022-07-25 17:44:33 +02:00
sysfs.h
transaction.c Revert "btrfs: turn fs_roots_radix in btrfs_fs_info into an XArray" 2022-07-15 19:14:28 +02:00
transaction.h btrfs: pass btrfs_fs_info for deleting snapshots and cleaner 2022-03-14 13:13:52 +01:00
tree-checker.c btrfs: tree-checker: check extent buffer owner against owner rootid 2022-05-16 17:03:09 +02:00
tree-checker.h btrfs: tree-checker: check extent buffer owner against owner rootid 2022-05-16 17:03:09 +02:00
tree-defrag.c btrfs: remove unnecessary extent root check in btrfs_defrag_leaves 2022-01-03 15:09:48 +01:00
tree-log.c btrfs: fix typos in comments 2022-07-25 17:44:33 +02:00
tree-log.h btrfs: avoid inode logging during rename and link when possible 2022-03-14 13:13:48 +01:00
tree-mod-log.c
tree-mod-log.h
ulist.c
ulist.h
uuid-tree.c btrfs: drop the _nr from the item helpers 2022-01-03 15:09:43 +01:00
verity.c btrfs: drop the _nr from the item helpers 2022-01-03 15:09:43 +01:00
volumes.c btrfs: quit early if the fs has no RAID56 support for raid56 related checks 2022-07-25 17:44:33 +02:00
volumes.h btrfs: add a helper to iterate through a btrfs_bio with sector sized chunks 2022-07-25 17:44:34 +02:00
xattr.c btrfs: use btrfs_for_each_slot in btrfs_listxattr 2022-05-16 17:03:08 +02:00
xattr.h
zlib.c Revert "btrfs: compression: drop kmap/kunmap from zlib" 2021-10-29 13:03:05 +02:00
zoned.c btrfs: zoned: fix comment description for sb_write_pointer logic 2022-07-25 17:44:33 +02:00
zoned.h btrfs: zoned: prevent allocation from previous data relocation BG 2022-06-21 14:43:48 +02:00
zstd.c btrfs: use non-bh spin_lock in zstd timer callback 2022-05-16 17:03:13 +02:00