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mirror of https://github.com/edk2-porting/linux-next.git synced 2025-01-22 20:43:56 +08:00
linux-next/fs/btrfs
Qu Wenruo 266a258678 btrfs: update comments in btrfs_invalidatepage()
The existing comments in btrfs_invalidatepage() don't really get to the
point, especially for what Private2 is really representing and how the
race avoidance is done.

The truth is, there are only three entrances to do ordered extent
accounting:

- btrfs_writepage_endio_finish_ordered()
- __endio_write_update_ordered()
  Those two entrance are just endio functions for dio and buffered
  write.

- btrfs_invalidatepage()

But there is a pitfall, in endio functions there is no check on whether
the ordered extent is already accounted.
They just blindly clear the Private2 bit and do the accounting.

So it's all btrfs_invalidatepage()'s responsibility to make sure we
won't do double account for the same sector.

That's why in btrfs_invalidatepage() we have to wait for page writeback,
this will ensure all submitted bios have finished, thus their endio
functions have finished the accounting on the ordered extent.

Then we also check page Private2 to ensure that, we only run ordered
extent accounting on pages who has no bio submitted.

This patch will rework related comments to make it more clear on the
race and how we use wait_on_page_writeback() and Private2 to prevent
double accounting on ordered extent.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2021-06-21 15:19:08 +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: make free space cache size consistent across different PAGE_SIZE 2021-06-21 15:19:08 +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: pass btrfs_inode to btrfs_writepage_endio_finish_ordered() 2021-06-21 15:19:08 +02:00
compression.h btrfs: optimize variables size in btrfs_submit_compressed_write 2021-06-21 15:19:07 +02:00
ctree.c btrfs: always abort the transaction if we abort a trans handle 2021-06-21 15:19:06 +02:00
ctree.h btrfs: pass btrfs_inode to btrfs_writepage_endio_finish_ordered() 2021-06-21 15:19:08 +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: abort transaction if we fail to update the delayed inode 2021-06-21 15:19:05 +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: add cancellable chunk relocation support 2021-06-21 15:19:07 +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: pass btrfs_inode to btrfs_writepage_endio_finish_ordered() 2021-06-21 15:19:08 +02:00
extent_io.h btrfs: refactor submit_extent_page() to make bio and its flag tracing easier 2021-06-21 15:19:08 +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
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: always abort the transaction if we abort a trans handle 2021-06-21 15:19:06 +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: use list_last_entry in add_falloc_range 2021-06-21 15:19:07 +02:00
free-space-cache.c btrfs: don't set the full sync flag when truncation does not touch extents 2021-06-21 15:19:05 +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
inode-item.c btrfs: locking: rip out path->leave_spinning 2020-12-08 15:54:02 +01:00
inode.c btrfs: update comments in btrfs_invalidatepage() 2021-06-21 15:19:08 +02:00
ioctl.c btrfs: add device delete cancel 2021-06-21 15:19:07 +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: refactor how we finish ordered extent io for endio functions 2021-06-21 15:19:08 +02:00
ordered-data.h btrfs: refactor how we finish ordered extent io for endio functions 2021-06-21 15:19:08 +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
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
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: add cancellable chunk relocation support 2021-06-21 15:19:07 +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: fix subpage repair error caused by hard coded PAGE_SIZE 2021-06-21 15:19:07 +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: always abort the transaction if we abort a trans handle 2021-06-21 15:19:06 +02:00
sysfs.c btrfs: sysfs: fix format string for some discard stats 2021-06-21 15:19:06 +02:00
sysfs.h btrfs: split and refactor btrfs_sysfs_remove_devices_dir 2020-10-07 12:12:21 +02:00
transaction.c btrfs: clear defrag status of a root if starting transaction fails 2021-06-21 15:19:06 +02:00
transaction.h btrfs: always abort the transaction if we abort a trans handle 2021-06-21 15:19:06 +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 btrfs: avoid unnecessary logging of xattrs during fast fsyncs 2021-06-21 15:19:07 +02:00
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 the unused parameter @len for btrfs_bio_fits_in_stripe() 2021-06-21 15:19:08 +02:00
volumes.h btrfs: remove the unused parameter @len for btrfs_bio_fits_in_stripe() 2021-06-21 15:19:08 +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