David Sterba eb3b505366 btrfs: scrub: per-device bandwidth control ... Add sysfs interface to limit io during scrub. We relied on the ionice interface to do that, eg. the idle class let the system usable while scrub was running. This has changed when mq-deadline got widespread and did not implement the scheduling classes. That was a CFQ thing that got deleted. We've got numerous complaints from users about degraded performance. Currently only BFQ supports that but it's not a common scheduler and we can't ask everybody to switch to it. Alternatively the cgroup io limiting can be used but that also a non-trivial setup (v2 required, the controller must be enabled on the system). This can still be used if desired. Other ideas that have been explored: piggy-back on ionice (that is set per-process and is accessible) and interpret the class and classdata as bandwidth limits, but this does not have enough flexibility as there are only 8 allowed and we'd have to map fixed limits to each value. Also adjusting the value would need to lookup the process that currently runs scrub on the given device, and the value is not sticky so would have to be adjusted each time scrub runs. Running out of options, sysfs does not look that bad: - it's accessible from scripts, or udev rules - the name is similar to what MD-RAID has (/proc/sys/dev/raid/speed_limit_max or /sys/block/mdX/md/sync_speed_max) - the value is sticky at least for filesystem mount time - adjusting the value has immediate effect - sysfs is available in constrained environments (eg. system rescue) - the limit also applies to device replace Sysfs: - raw value is in bytes - values written to the file accept suffixes like K, M - file is in the per-device directory /sys/fs/btrfs/FSID/devinfo/DEVID/scrub_speed_max - 0 means use default priority of IO The scheduler is a simple deadline one and the accuracy is up to nearest 128K. Signed-off-by: David Sterba <dsterba@suse.com>		2021-06-21 15:19:05 +02:00
..
tests	idmapped-mounts-v5.12	2021-02-23 13:39:45 -08:00
acl.c	fs: make helpers idmap mount aware	2021-01-24 14:27:20 +01:00
async-thread.c	Btrfs: fix crash during unmount due to race with delayed inode workers	2020-03-23 17:01:51 +01:00
async-thread.h	Btrfs: fix crash during unmount due to race with delayed inode workers	2020-03-23 17:01:51 +01:00
backref.c	btrfs: move the tree mod log code into its own file	2021-04-19 17:25:16 +02:00
backref.h	btrfs: add asserts for deleting backref cache nodes	2021-02-08 22:58:56 +01:00
block-group.c	btrfs: zoned: fix negative space_info->bytes_readonly	2021-06-17 11:12:14 +02:00
block-group.h	btrfs: zoned: automatically reclaim zones	2021-04-20 20:46:31 +02:00
block-rsv.c	btrfs: introduce mount option rescue=ignorebadroots	2020-12-08 15:53:41 +01:00
block-rsv.h	btrfs: Remove __ prefix from btrfs_block_rsv_release	2020-03-23 17:01:55 +01:00
btrfs_inode.h	btrfs: remove stale comment and logic from btrfs_inode_in_log()	2021-04-19 17:25:16 +02:00
check-integrity.c	btrfs: integrity-checker: convert block context kmap's to kmap_local_page	2021-04-19 17:25:16 +02:00
check-integrity.h	btrfs: remove btrfsic_submit_bh()	2020-03-23 17:01:39 +01:00
compression.c	btrfs: zoned: factor out zoned device lookup	2021-06-21 15:19:05 +02:00
compression.h	btrfs: compression: move declarations to header	2020-10-07 12:06:55 +02:00
ctree.c	btrfs: improve btree readahead for full send operations	2021-04-19 17:25:17 +02:00
ctree.h	btrfs: make btrfs_verify_data_csum() to return a bitmap	2021-06-21 15:19:05 +02:00
delalloc-space.c	btrfs: fix parameter description of btrfs_inode_rsv_release/btrfs_delalloc_release_space	2021-02-08 22:58:54 +01:00
delalloc-space.h	btrfs: make btrfs_delalloc_reserve_space take btrfs_inode	2020-07-27 12:55:36 +02:00
delayed-inode.c	btrfs: use btrfs_inode_lock/btrfs_inode_unlock inode lock helpers	2021-04-19 17:25:15 +02:00
delayed-inode.h	btrfs: make btrfs_delayed_update_inode take btrfs_inode	2020-12-08 15:54:10 +01:00
delayed-ref.c	btrfs: update debug message when checking seq number of a delayed ref	2021-04-19 17:25:17 +02:00
delayed-ref.h	btrfs: only let one thread pre-flush delayed refs in commit	2021-02-08 22:58:56 +01:00
dev-replace.c	btrfs: do not initialize dev replace for bad dev root	2021-03-17 19:42:14 +01:00
dev-replace.h	btrfs: zoned: mark block groups to copy for device-replace	2021-02-09 02:46:07 +01:00
dir-item.c	btrfs: locking: rip out path->leave_spinning	2020-12-08 15:54:02 +01:00
discard.c	btrfs: document now parameter of peek_discard_list	2021-02-08 22:58:53 +01:00
discard.h	btrfs: cleanup btrfs_discard_update_discardable usage	2020-12-08 15:54:02 +01:00
disk-io.c	btrfs: rename check_async_write and let it return bool	2021-06-21 15:19:04 +02:00
disk-io.h	btrfs: split alloc_log_tree()	2021-02-09 02:46:07 +01:00
export.c	btrfs: locking: rip out path->leave_spinning	2020-12-08 15:54:02 +01:00
export.h	btrfs: export helpers for subvolume name/id resolution	2020-03-23 17:01:42 +01:00
extent_io.c	btrfs: zoned: factor out zoned device lookup	2021-06-21 15:19:05 +02:00
extent_io.h	btrfs: remove io_failure_record::in_validation	2021-06-21 15:19:05 +02:00
extent_map.c	btrfs: fix parameter description of btrfs_add_extent_mapping	2021-02-08 22:58:53 +01:00
extent_map.h	btrfs: remove extent_map::bdev	2019-11-18 23:43:44 +01:00
extent-io-tree.h	btrfs: use fixed width int type for extent_state::state	2020-12-08 15:54:13 +01:00
extent-tree.c	btrfs: return errors from btrfs_del_csums in cleanup_ref_head	2021-05-27 23:30:55 +02:00
file-item.c	btrfs: fix fsync failure and transaction abort after writes to prealloc extents	2021-05-27 23:31:36 +02:00
file.c	btrfs: return value from btrfs_mark_extent_written() in case of error	2021-06-04 13:11:58 +02:00
free-space-cache.c	btrfs: initialize return variable in cleanup_free_space_cache_v1	2021-05-04 18:05:15 +02:00
free-space-cache.h	btrfs: zoned: track unusable bytes for zones	2021-02-09 02:46:03 +01:00
free-space-tree.c	btrfs: fix possible free space tree corruption with online conversion	2021-01-25 18:44:37 +01:00
free-space-tree.h	btrfs: rename btrfs_block_group_cache	2019-11-18 17:51:51 +01:00
inode-item.c	btrfs: locking: rip out path->leave_spinning	2020-12-08 15:54:02 +01:00
inode.c	btrfs: submit read time repair only for each corrupted sector	2021-06-21 15:19:05 +02:00
ioctl.c	btrfs: return EAGAIN if defrag is canceled	2021-06-21 15:19:05 +02:00
Kconfig	btrfs: switch to iomap for direct IO	2020-10-07 12:06:57 +02:00
locking.c	btrfs: remove the recurse parameter from __btrfs_tree_read_lock	2020-12-08 15:54:09 +01:00
locking.h	btrfs: remove the recurse parameter from __btrfs_tree_read_lock	2020-12-08 15:54:09 +01:00
lzo.c	btrfs: convert kmap to kmap_local_page, simple cases	2021-04-19 17:25:16 +02:00
Makefile	btrfs: move the tree mod log code into its own file	2021-04-19 17:25:16 +02:00
misc.h	btrfs: rename tree_entry to rb_simple_node and export it	2020-05-25 11:25:19 +02:00
ordered-data.c	btrfs: zoned: fix silent data loss after failure splitting ordered extent	2021-04-28 20:09:38 +02:00
ordered-data.h	btrfs: fix comment for btrfs ordered extent flag bits	2021-04-19 17:25:14 +02:00
orphan.c
print-tree.c	btrfs: print the actual offset in btrfs_root_name	2021-01-07 17:25:05 +01:00
print-tree.h	btrfs: print the actual offset in btrfs_root_name	2021-01-07 17:25:05 +01:00
props.c	btrfs: simplify iget helpers	2020-05-25 11:25:37 +02:00
props.h	btrfs: delete unused function btrfs_set_prop_trans	2019-04-29 19:02:54 +02:00
qgroup.c	btrfs: fix deadlock when cloning inline extents and using qgroups	2021-04-28 20:09:47 +02:00
qgroup.h	btrfs: export and rename qgroup_reserve_meta	2021-03-02 16:58:30 +01:00
raid56.c	CFI on arm64 series for v5.13-rc1	2021-04-27 10:16:46 -07:00
raid56.h	btrfs: constify map parameter for nr_parity_stripes and nr_data_stripes	2019-07-01 13:34:58 +02:00
rcu-string.h	btrfs: rcu-string: Replace zero-length array with flexible-array member	2020-03-23 17:01:53 +01:00
reada.c	btrfs: subpage: make readahead work properly	2021-03-16 11:06:21 +01:00
ref-verify.c	btrfs: ref-verify: use 'inline void' keyword ordering	2021-03-02 16:55:40 +01:00
ref-verify.h
reflink.c	for-5.13-rc4-tag	2021-06-03 11:37:14 -07:00
reflink.h	Btrfs: move all reflink implementation code into its own file	2020-03-23 17:01:54 +01:00
relocation.c	btrfs: check return value of btrfs_commit_transaction in relocation	2021-04-19 17:25:22 +02:00
root-tree.c	btrfs: qgroup: fix qgroup meta rsv leak for subvolume operations	2020-10-07 12:12:13 +02:00
scrub.c	btrfs: scrub: per-device bandwidth control	2021-06-21 15:19:05 +02:00
send.c	btrfs: fix deadlock when cloning inline extents and using qgroups	2021-04-28 20:09:47 +02:00
send.h	btrfs: send: avoid copying file data	2020-10-07 12:13:17 +02:00
space-info.c	btrfs: handle preemptive delalloc flushing slightly differently	2021-06-21 15:19:04 +02:00
space-info.h	btrfs: zoned: track unusable bytes for zones	2021-02-09 02:46:03 +01:00
struct-funcs.c	btrfs: handle sectorsize < PAGE_SIZE case for extent buffer accessors	2020-12-09 19:16:10 +01:00
subpage.c	btrfs: subpage: add overview comments	2021-04-19 17:25:18 +02:00
subpage.h	btrfs: subpage: introduce helpers for writeback status	2021-04-19 17:25:18 +02:00
super.c	btrfs: more graceful errors/warnings on 32bit systems when reaching limits	2021-04-20 19:56:50 +02:00
sysfs.c	btrfs: scrub: per-device bandwidth control	2021-06-21 15:19:05 +02:00
sysfs.h	btrfs: split and refactor btrfs_sysfs_remove_devices_dir	2020-10-07 12:12:21 +02:00
transaction.c	btrfs: fix race between transaction aborts and fsyncs leading to use-after-free	2021-04-19 17:25:22 +02:00
transaction.h	btrfs: fix exhaustion of the system chunk array due to concurrent allocations	2021-04-19 17:25:17 +02:00
tree-checker.c	btrfs: tree-checker: check for BTRFS_BLOCK_FLAG_FULL_BACKREF being set improperly	2021-04-19 17:25:21 +02:00
tree-checker.h
tree-defrag.c	btrfs: locking: remove all the blocking helpers	2020-12-08 15:54:01 +01:00
tree-log.c	for-5.13-rc5-tag	2021-06-09 13:34:48 -07:00
tree-log.h	btrfs: make fast fsyncs wait only for writeback	2020-10-07 12:06:56 +02:00
tree-mod-log.c	btrfs: fix race when picking most recent mod log operation for an old root	2021-04-20 19:27:17 +02:00
tree-mod-log.h	btrfs: add and use helper to get lowest sequence number for the tree mod log	2021-04-19 17:25:17 +02:00
ulist.c
ulist.h
uuid-tree.c	btrfs: remove unnecessary casts in printk	2020-12-08 15:53:52 +01:00
volumes.c	btrfs: remove stale comment for argument seed of btrfs_find_device	2021-06-21 15:19:04 +02:00
volumes.h	btrfs: scrub: per-device bandwidth control	2021-06-21 15:19:05 +02:00
xattr.c	for-5.12-rc1-tag	2021-03-05 12:21:14 -08:00
xattr.h
zlib.c	btrfs: use memzero_page() instead of open coded kmap pattern	2021-05-05 11:27:27 -07:00
zoned.c	btrfs: zoned: factor out zoned device lookup	2021-06-21 15:19:05 +02:00
zoned.h	btrfs: zoned: factor out zoned device lookup	2021-06-21 15:19:05 +02:00
zstd.c	btrfs: use memzero_page() instead of open coded kmap pattern	2021-05-05 11:27:27 -07:00