btrfs: remove a pointless NULL check in btrfs_lookup_fs_root

btrfs_grab_root already checks for a NULL root itself.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Chris

btrfs: remove a pointless NULL check in btrfs_lookup_fs_root

btrfs_grab_root already checks for a NULL root itself.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: convert btrfs_get_global_root to use a switch statement

Use a switch statement instead of an endless chain of if statements
to make the code a little cleaner.

Reviewed-by: Johannes Thumshirn

btrfs: convert btrfs_get_global_root to use a switch statement

Use a switch statement instead of an endless chain of if statements
to make the code a little cleaner.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: fix the btrfs_get_global_root return value

btrfs_grab_root returns either the root or NULL, and the callers of
btrfs_get_global_root expect it to return the same. But all the more
recently a

btrfs: fix the btrfs_get_global_root return value

btrfs_grab_root returns either the root or NULL, and the callers of
btrfs_get_global_root expect it to return the same. But all the more
recently added roots instead return an ERR_PTR, so fix this.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: consolidate uuid comparisons in btrfs_validate_super

There are three ways the fsid is validated in btrfs_validate_super():

- verify that super_copy::fsid is the same as fs_devices::fsid

- i

btrfs: consolidate uuid comparisons in btrfs_validate_super

There are three ways the fsid is validated in btrfs_validate_super():

- verify that super_copy::fsid is the same as fs_devices::fsid

- if the metadata_uuid flag is set, verify if super_copy::metadata_uuid
and fs_devices::metadata_uuid are the same.

- a few lines below, often missed out, verify if dev_item::fsid is the
same as fs_devices::metadata_uuid.

The function btrfs_validate_super() contains multiple if-statements with
memcmp() to check UUIDs. This patch consolidates them into a single
location.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: return bool from check_tree_block_fsid instead of int

Simplify the return type of check_tree_block_fsid() from int (1 or 0) to
bool. Its only user is interested in knowing the success or fail

btrfs: return bool from check_tree_block_fsid instead of int

Simplify the return type of check_tree_block_fsid() from int (1 or 0) to
bool. Its only user is interested in knowing the success or failure.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: stop using lock_extent in btrfs_buffer_uptodate

The only other place that locks extents on the btree inode is
read_extent_buffer_subpage while reading in the partial page for a
buffer. This

btrfs: stop using lock_extent in btrfs_buffer_uptodate

The only other place that locks extents on the btree inode is
read_extent_buffer_subpage while reading in the partial page for a
buffer. This means locking the extent in btrfs_buffer_uptodate does not
synchronize with anything on non-subpage file systems, and on subpage
file systems it only waits for a parallel read(-ahead) to finish,
which seems to be counter to what the callers actually expect.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: remove the extent_buffer lookup in btree block checksumming

The checksumming of btree blocks always operates on the entire
extent_buffer, and because btree blocks are always allocated contigu

btrfs: remove the extent_buffer lookup in btree block checksumming

The checksumming of btree blocks always operates on the entire
extent_buffer, and because btree blocks are always allocated contiguously
on disk they are never split by btrfs_submit_bio.

Simplify the checksumming code by finding the extent_buffer in the
btrfs_bio private data instead of trying to search through the bio_vec.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: use a separate end_io handler for read_extent_buffer

Now that we always use a single bio to read an extent_buffer, the buffer
can be passed to the end_io handler as private data. This allows

btrfs: use a separate end_io handler for read_extent_buffer

Now that we always use a single bio to read an extent_buffer, the buffer
can be passed to the end_io handler as private data. This allows
implementing a much simplified dedicated end I/O handler for metadata
reads.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: merge verify_parent_transid and btrfs_buffer_uptodate

verify_parent_transid is only called by btrfs_buffer_uptodate, which
confusingly inverts the return value. Merge the two functions and
r

btrfs: merge verify_parent_transid and btrfs_buffer_uptodate

verify_parent_transid is only called by btrfs_buffer_uptodate, which
confusingly inverts the return value. Merge the two functions and
reflow the parent_transid so that error handling is in a branch.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: move setting the buffer uptodate out of validate_extent_buffer

Setting the buffer uptodate in a function that is named as a validation
helper is a it confusing. Move the call from validate_e

btrfs: move setting the buffer uptodate out of validate_extent_buffer

Setting the buffer uptodate in a function that is named as a validation
helper is a it confusing. Move the call from validate_extent_buffer to
the one of its two callers that didn't already have a duplicate call
to set_extent_buffer_uptodate.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: don't hold an extra reference for redirtied buffers

When btrfs_redirty_list_add redirties a buffer, it also acquires
an extra reference that is released on transaction commit. But
this is no

btrfs: don't hold an extra reference for redirtied buffers

When btrfs_redirty_list_add redirties a buffer, it also acquires
an extra reference that is released on transaction commit. But
this is not required as buffers that are dirty or under writeback
are never freed (look for calls to extent_buffer_under_io())).

Remove the extra reference and the infrastructure used to drop it
again.

History behind redirty logic:

In the first place, it used releasing_list to hold all the
to-be-released extent buffers, and decided which buffers to re-dirty at
the commit time. Then, in a later version, the behaviour got changed to
re-dirty a necessary buffer and add re-dirtied one to the list in
btrfs_free_tree_block(). In short, the list was there mostly for the
patch series' historical reason.

Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
[ add Naohiro's comment regarding history ]
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: fix dirty_metadata_bytes for redirtied buffers

dirty_metadata_bytes is decremented in both places that clear the dirty
bit in a buffer, but only incremented in btrfs_mark_buffer_dirty, which

btrfs: fix dirty_metadata_bytes for redirtied buffers

dirty_metadata_bytes is decremented in both places that clear the dirty
bit in a buffer, but only incremented in btrfs_mark_buffer_dirty, which
means that a buffer that is redirtied using btrfs_redirty_list_add won't
be added to dirty_metadata_bytes, but it will be subtracted when written
out, leading an inconsistency in the counter.

Move the dirty_metadata_bytes from btrfs_mark_buffer_dirty into
set_extent_buffer_dirty to also account for the redirty case, and remove
the now unused set_extent_buffer_dirty return value.

Fixes: d3575156f662 ("btrfs: zoned: redirty released extent buffers")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: move btrfs_verify_level_key into tree-checker.c

This is more a buffer validation helper, move it into the tree-checker
files where it makes more sense.

Reviewed-by: Johannes Thumshirn <johan

btrfs: move btrfs_verify_level_key into tree-checker.c

This is more a buffer validation helper, move it into the tree-checker
files where it makes more sense.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: simplify btrfs_check_leaf_* helpers into a single helper

We have two helpers for checking leaves, because we have an extra check
for debugging in btrfs_mark_buffer_dirty(), and at that stage

btrfs: simplify btrfs_check_leaf_* helpers into a single helper

We have two helpers for checking leaves, because we have an extra check
for debugging in btrfs_mark_buffer_dirty(), and at that stage we may
have item data that isn't consistent yet. However we can handle this
case internally in the helper, if BTRFS_HEADER_FLAG_WRITTEN is set we
know the buffer should be internally consistent, otherwise we need to
skip checking the item data.

Simplify this helper down a single helper and handle the item data
checking logic internally to the helper.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: remove hipri_workers workqueue

Now that btrfs_wq_submit_bio is never called for synchronous I/O,
the hipri_workers workqueue is not used anymore and can be removed.

Reviewed-by: Chris Mason

btrfs: remove hipri_workers workqueue

Now that btrfs_wq_submit_bio is never called for synchronous I/O,
the hipri_workers workqueue is not used anymore and can be removed.

Reviewed-by: Chris Mason <clm@fb.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: do not ASSERT() on duplicated global roots

[BUG]
Syzbot reports a reproducible ASSERT() when using rescue=usebackuproot
mount option on a corrupted fs.

The full report can be found here:
htt

btrfs: do not ASSERT() on duplicated global roots

[BUG]
Syzbot reports a reproducible ASSERT() when using rescue=usebackuproot
mount option on a corrupted fs.

The full report can be found here:
https://syzkaller.appspot.com/bug?extid=c4614eae20a166c25bf0

BTRFS error (device loop0: state C): failed to load root csum
assertion failed: !tmp, in fs/btrfs/disk-io.c:1103
------------[ cut here ]------------
kernel BUG at fs/btrfs/ctree.h:3664!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 3608 Comm: syz-executor356 Not tainted 6.0.0-rc7-syzkaller-00029-g3800a713b607 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
RIP: 0010:assertfail+0x1a/0x1c fs/btrfs/ctree.h:3663
RSP: 0018:ffffc90003aaf250 EFLAGS: 00010246
RAX: 0000000000000032 RBX: 0000000000000000 RCX: f21c13f886638400
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffff888021c640a0 R08: ffffffff816bd38d R09: ffffed10173667f1
R10: ffffed10173667f1 R11: 1ffff110173667f0 R12: dffffc0000000000
R13: ffff8880229c21f7 R14: ffff888021c64060 R15: ffff8880226c0000
FS: 0000555556a73300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a2637d7a00 CR3: 00000000709c4000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
btrfs_global_root_insert+0x1a7/0x1b0 fs/btrfs/disk-io.c:1103
load_global_roots_objectid+0x482/0x8c0 fs/btrfs/disk-io.c:2467
load_global_roots fs/btrfs/disk-io.c:2501 [inline]
btrfs_read_roots fs/btrfs/disk-io.c:2528 [inline]
init_tree_roots+0xccb/0x203c fs/btrfs/disk-io.c:2939
open_ctree+0x1e53/0x33df fs/btrfs/disk-io.c:3574
btrfs_fill_super+0x1c6/0x2d0 fs/btrfs/super.c:1456
btrfs_mount_root+0x885/0x9a0 fs/btrfs/super.c:1824
legacy_get_tree+0xea/0x180 fs/fs_context.c:610
vfs_get_tree+0x88/0x270 fs/super.c:1530
fc_mount fs/namespace.c:1043 [inline]
vfs_kern_mount+0xc9/0x160 fs/namespace.c:1073
btrfs_mount+0x3d3/0xbb0 fs/btrfs/super.c:1884

[CAUSE]
Since the introduction of global roots, we handle
csum/extent/free-space-tree roots as global roots, even if no
extent-tree-v2 feature is enabled.

So for regular csum/extent/fst roots, we load them into
fs_info::global_root_tree rb tree.

And we should not expect any conflicts in that rb tree, thus we have an
ASSERT() inside btrfs_global_root_insert().

But rescue=usebackuproot can break the assumption, as we will try to
load those trees again and again as long as we have bad roots and have
backup roots slot remaining.

So in that case we can have conflicting roots in the rb tree, and
triggering the ASSERT() crash.

[FIX]
We can safely remove that ASSERT(), as the caller will properly put the
offending root.

To make further debugging easier, also add two explicit error messages:

- Error message for conflicting global roots
- Error message when using backup roots slot

Reported-by: syzbot+a694851c6ab28cbcfb9c@syzkaller.appspotmail.com
Fixes: abed4aaae4f7 ("btrfs: track the csum, extent, and free space trees in a rb tree")
CC: stable@vger.kernel.org # 6.1+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: subpage: fix a crash in metadata repair path

[BUG]
Test case btrfs/027 would crash with subpage (64K page size, 4K
sectorsize) with the following dying messages:

debug: map_length=16384 le

btrfs: subpage: fix a crash in metadata repair path

[BUG]
Test case btrfs/027 would crash with subpage (64K page size, 4K
sectorsize) with the following dying messages:

debug: map_length=16384 length=65536 type=metadata|raid6(0x104)
assertion failed: map_length >= length, in fs/btrfs/volumes.c:8093
------------[ cut here ]------------
kernel BUG at fs/btrfs/messages.c:259!
Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
Call trace:
btrfs_assertfail+0x28/0x2c [btrfs]
btrfs_map_repair_block+0x150/0x2b8 [btrfs]
btrfs_repair_io_failure+0xd4/0x31c [btrfs]
btrfs_read_extent_buffer+0x150/0x16c [btrfs]
read_tree_block+0x38/0xbc [btrfs]
read_tree_root_path+0xfc/0x1bc [btrfs]
btrfs_get_root_ref.part.0+0xd4/0x3a8 [btrfs]
open_ctree+0xa30/0x172c [btrfs]
btrfs_mount_root+0x3c4/0x4a4 [btrfs]
legacy_get_tree+0x30/0x60
vfs_get_tree+0x28/0xec
vfs_kern_mount.part.0+0x90/0xd4
vfs_kern_mount+0x14/0x28
btrfs_mount+0x114/0x418 [btrfs]
legacy_get_tree+0x30/0x60
vfs_get_tree+0x28/0xec
path_mount+0x3e0/0xb64
__arm64_sys_mount+0x200/0x2d8
invoke_syscall+0x48/0x114
el0_svc_common.constprop.0+0x60/0x11c
do_el0_svc+0x38/0x98
el0_svc+0x40/0xa8
el0t_64_sync_handler+0xf4/0x120
el0t_64_sync+0x190/0x194
Code: aa0403e2 b0fff060 91010000 959c2024 (d4210000)

[CAUSE]
In btrfs/027 we test RAID6 with missing devices, in this particular
case, we're repairing a metadata at the end of a data stripe.

But at btrfs_repair_io_failure(), we always pass a full PAGE for repair,
and for subpage case this can cross stripe boundary and lead to the
above BUG_ON().

This metadata repair code is always there, since the introduction of
subpage support, but this can trigger BUG_ON() after the bio split
ability at btrfs_map_bio().

[FIX]
Instead of passing the old PAGE_SIZE, we calculate the correct length
based on the eb size and page size for both regular and subpage cases.

CC: stable@vger.kernel.org # 6.3+
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: fix csum_tree_block page iteration to avoid tripping on -Werror=array-bounds

When compiling on a MIPS 64-bit machine we get these warnings:

In file included from ./arch/mips/include/asm/

btrfs: fix csum_tree_block page iteration to avoid tripping on -Werror=array-bounds

When compiling on a MIPS 64-bit machine we get these warnings:

In file included from ./arch/mips/include/asm/cacheflush.h:13,
from ./include/linux/cacheflush.h:5,
from ./include/linux/highmem.h:8,
from ./include/linux/bvec.h:10,
from ./include/linux/blk_types.h:10,
from ./include/linux/blkdev.h:9,
from fs/btrfs/disk-io.c:7:
fs/btrfs/disk-io.c: In function ‘csum_tree_block’:
fs/btrfs/disk-io.c:100:34: error: array subscript 1 is above array bounds of ‘struct page *[1]’ [-Werror=array-bounds]
100 | kaddr = page_address(buf->pages[i]);
| ~~~~~~~~~~^~~
./include/linux/mm.h:2135:48: note: in definition of macro ‘page_address’
2135 | #define page_address(page) lowmem_page_address(page)
| ^~~~
cc1: all warnings being treated as errors

We can check if i overflows to solve the problem. However, this doesn't make
much sense, since i == 1 and num_pages == 1 doesn't execute the body of the loop.
In addition, i < num_pages can also ensure that buf->pages[i] will not cross
the boundary. Unfortunately, this doesn't help with the problem observed here:
gcc still complains.

To fix this add a compile-time condition for the extent buffer page
array size limit, which would eventually lead to eliminating the whole
for loop.

CC: stable@vger.kernel.org # 5.10+
Signed-off-by: pengfuyuan <pengfuyuan@kylinos.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: use nofs when cleaning up aborted transactions

Our CI system caught a lockdep splat:

======================================================
WARNING: possible circular locking dependency

btrfs: use nofs when cleaning up aborted transactions

Our CI system caught a lockdep splat:

======================================================
WARNING: possible circular locking dependency detected
6.3.0-rc7+ #1167 Not tainted
------------------------------------------------------
kswapd0/46 is trying to acquire lock:
ffff8c6543abd650 (sb_internal#2){++++}-{0:0}, at: btrfs_commit_inode_delayed_inode+0x5f/0x120

but task is already holding lock:
ffffffffabe61b40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x4aa/0x7a0

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (fs_reclaim){+.+.}-{0:0}:
fs_reclaim_acquire+0xa5/0xe0
kmem_cache_alloc+0x31/0x2c0
alloc_extent_state+0x1d/0xd0
__clear_extent_bit+0x2e0/0x4f0
try_release_extent_mapping+0x216/0x280
btrfs_release_folio+0x2e/0x90
invalidate_inode_pages2_range+0x397/0x470
btrfs_cleanup_dirty_bgs+0x9e/0x210
btrfs_cleanup_one_transaction+0x22/0x760
btrfs_commit_transaction+0x3b7/0x13a0
create_subvol+0x59b/0x970
btrfs_mksubvol+0x435/0x4f0
__btrfs_ioctl_snap_create+0x11e/0x1b0
btrfs_ioctl_snap_create_v2+0xbf/0x140
btrfs_ioctl+0xa45/0x28f0
__x64_sys_ioctl+0x88/0xc0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc

-> #0 (sb_internal#2){++++}-{0:0}:
__lock_acquire+0x1435/0x21a0
lock_acquire+0xc2/0x2b0
start_transaction+0x401/0x730
btrfs_commit_inode_delayed_inode+0x5f/0x120
btrfs_evict_inode+0x292/0x3d0
evict+0xcc/0x1d0
inode_lru_isolate+0x14d/0x1e0
__list_lru_walk_one+0xbe/0x1c0
list_lru_walk_one+0x58/0x80
prune_icache_sb+0x39/0x60
super_cache_scan+0x161/0x1f0
do_shrink_slab+0x163/0x340
shrink_slab+0x1d3/0x290
shrink_node+0x300/0x720
balance_pgdat+0x35c/0x7a0
kswapd+0x205/0x410
kthread+0xf0/0x120
ret_from_fork+0x29/0x50

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(fs_reclaim);
lock(sb_internal#2);
lock(fs_reclaim);
lock(sb_internal#2);

*** DEADLOCK ***

3 locks held by kswapd0/46:
#0: ffffffffabe61b40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x4aa/0x7a0
#1: ffffffffabe50270 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x113/0x290
#2: ffff8c6543abd0e0 (&type->s_umount_key#44){++++}-{3:3}, at: super_cache_scan+0x38/0x1f0

stack backtrace:
CPU: 0 PID: 46 Comm: kswapd0 Not tainted 6.3.0-rc7+ #1167
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x58/0x90
check_noncircular+0xd6/0x100
? save_trace+0x3f/0x310
? add_lock_to_list+0x97/0x120
__lock_acquire+0x1435/0x21a0
lock_acquire+0xc2/0x2b0
? btrfs_commit_inode_delayed_inode+0x5f/0x120
start_transaction+0x401/0x730
? btrfs_commit_inode_delayed_inode+0x5f/0x120
btrfs_commit_inode_delayed_inode+0x5f/0x120
btrfs_evict_inode+0x292/0x3d0
? lock_release+0x134/0x270
? __pfx_wake_bit_function+0x10/0x10
evict+0xcc/0x1d0
inode_lru_isolate+0x14d/0x1e0
__list_lru_walk_one+0xbe/0x1c0
? __pfx_inode_lru_isolate+0x10/0x10
? __pfx_inode_lru_isolate+0x10/0x10
list_lru_walk_one+0x58/0x80
prune_icache_sb+0x39/0x60
super_cache_scan+0x161/0x1f0
do_shrink_slab+0x163/0x340
shrink_slab+0x1d3/0x290
shrink_node+0x300/0x720
balance_pgdat+0x35c/0x7a0
kswapd+0x205/0x410
? __pfx_autoremove_wake_function+0x10/0x10
? __pfx_kswapd+0x10/0x10
kthread+0xf0/0x120
? __pfx_kthread+0x10/0x10
ret_from_fork+0x29/0x50
</TASK>

This happens because when we abort the transaction in the transaction
commit path we call invalidate_inode_pages2_range on our block group
cache inodes (if we have space cache v1) and any delalloc inodes we may
have. The plain invalidate_inode_pages2_range() call passes through
GFP_KERNEL, which makes sense in most cases, but not here. Wrap these
two invalidate callees with memalloc_nofs_save/memalloc_nofs_restore to
make sure we don't end up with the fs reclaim dependency under the
transaction dependency.

CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: make clear_cache mount option to rebuild FST without disabling it

Previously clear_cache mount option would simply disable free-space-tree
feature temporarily then re-enable it to rebuild the

btrfs: make clear_cache mount option to rebuild FST without disabling it

Previously clear_cache mount option would simply disable free-space-tree
feature temporarily then re-enable it to rebuild the whole free space
tree.

But this is problematic for block-group-tree feature, as we have an
artificial dependency on free-space-tree feature.

If we go the existing method, after clearing the free-space-tree
feature, we would flip the filesystem to read-only mode, as we detect a
super block write with block-group-tree but no free-space-tree feature.

This patch would change the behavior by properly rebuilding the free
space tree without disabling this feature, thus allowing clear_cache
mount option to work with block group tree.

Now we can mount a filesystem with block-group-tree feature and
clear_mount option:

$ mkfs.btrfs -O block-group-tree /dev/test/scratch1 -f
$ sudo mount /dev/test/scratch1 /mnt/btrfs -o clear_cache
$ sudo dmesg -t | head -n 5
BTRFS info (device dm-1): force clearing of disk cache
BTRFS info (device dm-1): using free space tree
BTRFS info (device dm-1): auto enabling async discard
BTRFS info (device dm-1): rebuilding free space tree
BTRFS info (device dm-1): checking UUID tree

CC: stable@vger.kernel.org # 6.1+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: use test_and_clear_bit() in wait_dev_flush()

The function wait_dev_flush() tests for the BTRFS_DEV_STATE_FLUSH_SENT
bit and then clears it separately. Instead, use test_and_clear_bit().
Thoug

btrfs: use test_and_clear_bit() in wait_dev_flush()

The function wait_dev_flush() tests for the BTRFS_DEV_STATE_FLUSH_SENT
bit and then clears it separately. Instead, use test_and_clear_bit().
Though we don't need to do the atomic test and clear, it's following a
common pattern.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: change wait_dev_flush() return type to bool

The flush error code is maintained in btrfs_device::last_flush_error, so
there is no point in returning it in wait_dev_flush() when it is not being

btrfs: change wait_dev_flush() return type to bool

The flush error code is maintained in btrfs_device::last_flush_error, so
there is no point in returning it in wait_dev_flush() when it is not being
used. Instead, we can return a boolean value.

Note that even though btrfs_device::last_flush_error may not be used, we
will keep it for now.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: open code check_barrier_error()

check_barrier_error() is almost a single line function, and just calls
btrfs_check_rw_degradable(). Instead, open code it.

Signed-off-by: Anand Jain <anand.ja

btrfs: open code check_barrier_error()

check_barrier_error() is almost a single line function, and just calls
btrfs_check_rw_degradable(). Instead, open code it.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: move last_flush_error to write_dev_flush and wait_dev_flush

We parallelize the flush command across devices using our own code,
write_dev_flush() sends the flush command to each device and
wa

btrfs: move last_flush_error to write_dev_flush and wait_dev_flush

We parallelize the flush command across devices using our own code,
write_dev_flush() sends the flush command to each device and
wait_dev_flush() waits for the flush to complete on all devices. Errors
from each device are recorded at device->last_flush_error and reset to
BLK_STS_OK in write_dev_flush() and to the error, if any, in
wait_dev_flush(). These functions are called from barrier_all_devices().

This patch consolidates the use of device->last_flush_error in
write_dev_flush() and wait_dev_flush() to remove it from
barrier_all_devices().

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: remove obsolete delayed ref throttling logic when truncating items

We have this logic encapsulated in btrfs_should_throttle_delayed_refs()
where we try to estimate if running the current amou

btrfs: remove obsolete delayed ref throttling logic when truncating items

We have this logic encapsulated in btrfs_should_throttle_delayed_refs()
where we try to estimate if running the current amount of delayed
references we have will take more than half a second, and if so, the
caller btrfs_should_throttle_delayed_refs() should do something to
prevent more and more delayed refs from being accumulated.

This logic was added in commit 0a2b2a844af6 ("Btrfs: throttle delayed
refs better") and then further refined in commit a79b7d4b3e81 ("Btrfs:
async delayed refs"). The idea back then was that the caller of
btrfs_should_throttle_delayed_refs() would release its transaction
handle (by calling btrfs_end_transaction()) when that function returned
true, then btrfs_end_transaction() would trigger an async job to run
delayed references in a workqueue, and later start/join a transaction
again and do more work.

However we don't run delayed references asynchronously anymore, that
was removed in commit db2462a6ad3d ("btrfs: don't run delayed refs in
the end transaction logic"). That makes the logic that tries to estimate
how long we will take to run our current delayed references, at
btrfs_should_throttle_delayed_refs(), pointless as we don't take any
action to run delayed references anymore. We do have other type of
throttling, which consists of checking the size and reserved space of
the delayed and global block reserves, as well as if fluhsing delayed
references for the current transaction was already started, etc - this
is all done by btrfs_should_end_transaction(), and the only user of
btrfs_should_throttle_delayed_refs() does periodically call
btrfs_should_end_transaction().

So remove btrfs_should_throttle_delayed_refs() and the infrastructure
that keeps track of the average time used for running delayed references,
as well as adapting btrfs_truncate_inode_items() to call
btrfs_check_space_for_delayed_refs() instead.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...