alistair23-linux/fs/btrfs
Qu Wenruo 370a11b811 btrfs: qgroup: Introduce per-root swapped blocks infrastructure
To allow delayed subtree swap rescan, btrfs needs to record per-root
information about which tree blocks get swapped.  This patch introduces
the required infrastructure.

The designed workflow will be:

1) Record the subtree root block that gets swapped.

   During subtree swap:
   O = Old tree blocks
   N = New tree blocks
         reloc tree                         subvolume tree X
            Root                               Root
           /    \                             /    \
         NA     OB                          OA      OB
       /  |     |  \                      /  |      |  \
     NC  ND     OE  OF                   OC  OD     OE  OF

  In this case, NA and OA are going to be swapped, record (NA, OA) into
  subvolume tree X.

2) After subtree swap.
         reloc tree                         subvolume tree X
            Root                               Root
           /    \                             /    \
         OA     OB                          NA      OB
       /  |     |  \                      /  |      |  \
     OC  OD     OE  OF                   NC  ND     OE  OF

3a) COW happens for OB
    If we are going to COW tree block OB, we check OB's bytenr against
    tree X's swapped_blocks structure.
    If it doesn't fit any, nothing will happen.

3b) COW happens for NA
    Check NA's bytenr against tree X's swapped_blocks, and get a hit.
    Then we do subtree scan on both subtrees OA and NA.
    Resulting 6 tree blocks to be scanned (OA, OC, OD, NA, NC, ND).

    Then no matter what we do to subvolume tree X, qgroup numbers will
    still be correct.
    Then NA's record gets removed from X's swapped_blocks.

4)  Transaction commit
    Any record in X's swapped_blocks gets removed, since there is no
    modification to swapped subtrees, no need to trigger heavy qgroup
    subtree rescan for them.

This will introduce 128 bytes overhead for each btrfs_root even qgroup
is not enabled. This is to reduce memory allocations and potential
failures.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:26 +01:00
..
tests btrfs: remove always true if branch in find_delalloc_range 2018-12-17 14:51:44 +01:00
acl.c Btrfs: setup a nofs context for memory allocation at __btrfs_set_acl 2019-02-25 14:13:17 +01:00
async-thread.c btrfs: simplify workqueue name when allocating 2019-02-25 14:13:24 +01:00
async-thread.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
backref.c btrfs: Fix typos in comments and strings 2018-12-17 14:51:50 +01:00
backref.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
btrfs_inode.h Btrfs: fix fsync of files with multiple hard links in new directories 2018-12-17 14:51:43 +01:00
check-integrity.c btrfs: Fix typos in comments and strings 2018-12-17 14:51:50 +01:00
check-integrity.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
compression.c btrfs: Fix typos in comments and strings 2018-12-17 14:51:50 +01:00
compression.h btrfs: compression: Add linux/sizes.h for compression.h 2018-05-29 18:13:00 +02:00
ctree.c Btrfs: fix deadlock when allocating tree block during leaf/node split 2019-01-28 15:04:58 +01:00
ctree.h btrfs: qgroup: Introduce per-root swapped blocks infrastructure 2019-02-25 14:13:26 +01:00
dedupe.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
delayed-inode.c Btrfs: kill btrfs_clear_path_blocking 2018-10-15 17:23:38 +02:00
delayed-inode.h Btrfs: delayed-inode: use rb_first_cached for ins_root and del_root 2018-10-15 17:23:33 +02:00
delayed-ref.c btrfs: introduce delayed_refs_rsv 2018-12-17 14:51:46 +01:00
delayed-ref.h btrfs: add btrfs_delete_ref_head helper 2018-12-17 14:51:46 +01:00
dev-replace.c btrfs: merge btrfs_find_device and find_device 2019-02-25 14:13:24 +01:00
dev-replace.h btrfs: dev-replace: open code trivial locking helpers 2018-12-17 14:51:45 +01:00
dir-item.c btrfs: Remove root parameter from btrfs_insert_dir_item 2018-10-15 17:23:25 +02:00
disk-io.c btrfs: qgroup: Introduce per-root swapped blocks infrastructure 2019-02-25 14:13:26 +01:00
disk-io.h btrfs: drop extra enum initialization where using defaults 2018-12-17 14:51:43 +01:00
export.c btrfs: Remove 'objectid' member from struct btrfs_root 2018-10-15 17:23:25 +02:00
export.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
extent-tree.c btrfs: call btrfs_create_pending_block_groups unconditionally 2019-02-25 14:13:25 +01:00
extent_io.c btrfs: Remove unused arguments from btrfs_get_extent_fiemap 2019-02-25 14:13:17 +01:00
extent_io.h btrfs: Fix typos in comments and strings 2018-12-17 14:51:50 +01:00
extent_map.c btrfs: Remove impossible condition from mergable_maps 2019-02-25 14:13:21 +01:00
extent_map.h btrfs: Remove impossible condition from mergable_maps 2019-02-25 14:13:21 +01:00
file-item.c btrfs: replace btrfs_io_bio::end_io with a simple helper 2018-12-17 14:51:40 +01:00
file.c btrfs: Remove unused arguments from btrfs_get_extent_fiemap 2019-02-25 14:13:17 +01:00
free-space-cache.c Btrfs: fix deadlock on tree root leaf when finding free extent 2018-11-06 16:42:32 +01:00
free-space-cache.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
free-space-tree.c btrfs: use EXPORT_FOR_TESTS for conditionally exported functions 2018-12-17 14:51:37 +01:00
free-space-tree.h btrfs: Remove fs_info argument from add_to_free_space_tree 2018-05-28 18:07:36 +02:00
inode-item.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
inode-map.c btrfs: prune unused includes 2018-08-06 13:12:43 +02:00
inode-map.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
inode.c btrfs: Remove not_found_em label from btrfs_get_extent 2019-02-25 14:13:22 +01:00
ioctl.c btrfs: merge btrfs_find_device and find_device 2019-02-25 14:13:24 +01:00
Kconfig btrfs: add SPDX header to Kconfig 2018-04-12 16:29:55 +02:00
locking.c btrfs: replace waitqueue_actvie with cond_wake_up 2018-05-28 18:23:09 +02:00
locking.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
lzo.c btrfs: Fix typos in comments and strings 2018-12-17 14:51:50 +01:00
Makefile btrfs: Remove custom crc32c init code 2018-03-26 15:09:39 +02:00
math.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
ordered-data.c Btrfs: remove no longer used stuff for tracking pending ordered extents 2018-12-17 14:51:25 +01:00
ordered-data.h btrfs: switch BTRFS_ORDERED_* to enums 2018-12-17 14:51:43 +01:00
orphan.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
print-tree.c btrfs: annotate unlikely branches after V0 extent type removal 2018-08-06 13:12:41 +02:00
print-tree.h btrfs: print-tree: debugging output enhancement 2018-04-20 19:18:16 +02:00
props.c btrfs: property: Set incompat flag if lzo/zstd compression is set 2018-05-17 14:18:25 +02:00
props.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
qgroup.c btrfs: qgroup: Introduce per-root swapped blocks infrastructure 2019-02-25 14:13:26 +01:00
qgroup.h btrfs: qgroup: Introduce per-root swapped blocks infrastructure 2019-02-25 14:13:26 +01:00
raid56.c btrfs: Fix typos in comments and strings 2018-12-17 14:51:50 +01:00
raid56.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
rcu-string.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
reada.c btrfs: dev-replace: open code trivial locking helpers 2018-12-17 14:51:45 +01:00
ref-verify.c btrfs: Fix typos in comments and strings 2018-12-17 14:51:50 +01:00
ref-verify.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
relocation.c btrfs: qgroup: Introduce per-root swapped blocks infrastructure 2019-02-25 14:13:26 +01:00
root-tree.c btrfs: Remove fs_info from btrfs_add_root_ref 2018-08-06 13:13:00 +02:00
scrub.c btrfs: scrub: print messages when started or finished 2019-02-25 14:13:24 +01:00
send.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
send.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
struct-funcs.c btrfs: prune unused includes 2018-08-06 13:12:43 +02:00
super.c for-5.0-rc4-tag 2019-02-03 08:48:33 -08:00
sysfs.c btrfs: Add sysfs support for metadata_uuid feature 2018-12-17 14:51:37 +01:00
sysfs.h btrfs: drop extra enum initialization where using defaults 2018-12-17 14:51:43 +01:00
transaction.c btrfs: qgroup: Introduce per-root swapped blocks infrastructure 2019-02-25 14:13:26 +01:00
transaction.h btrfs: drop extra enum initialization where using defaults 2018-12-17 14:51:43 +01:00
tree-checker.c btrfs: Fix typos in comments and strings 2018-12-17 14:51:50 +01:00
tree-checker.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
tree-defrag.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
tree-log.c btrfs: Fix typos in comments and strings 2018-12-17 14:51:50 +01:00
tree-log.h Btrfs: remove no longer used io_err from btrfs_log_ctx 2018-12-17 14:51:31 +01:00
ulist.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
ulist.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
uuid-tree.c btrfs: Remove fs_info argument from btrfs_uuid_tree_rem 2018-05-30 16:46:53 +02:00
volumes.c btrfs: merge btrfs_find_device and find_device 2019-02-25 14:13:24 +01:00
volumes.h btrfs: merge btrfs_find_device and find_device 2019-02-25 14:13:24 +01:00
xattr.c Btrfs: use nofs context when initializing security xattrs to avoid deadlock 2018-12-17 14:51:49 +01:00
xattr.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
zlib.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
zstd.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00