Filipe Manana [Wed, 3 Jul 2024 10:07:26 +0000 (11:07 +0100)]
btrfs: use delayed iput during extent map shrinking
When putting an inode during extent map shrinking we're doing a standard
iput() but that may take a long time in case the inode is dirty and we are
doing the final iput that triggers eviction - the VFS will have to wait
for writeback before calling the btrfs evict callback (see
fs/inode.c:evict()).
This slows down the task running the shrinker which may have been
triggered while updating some tree for example, meaning locks are held
as well as an open transaction handle.
Also if the iput() ends up triggering eviction and the inode has no links
anymore, then we trigger item truncation which requires flushing delayed
items, space reservation to start a transaction and that may trigger the
space reclaim task and wait for it, resulting in deadlocks in case the
reclaim task needs for example to commit a transaction and the shrinker
is being triggered from a path holding a transaction handle.
Syzbot reported such a case with the following stack traces:
======================================================
WARNING: possible circular locking dependency detected
6.10.0-rc2-syzkaller-00010-g2ab795141095 #0 Not tainted
------------------------------------------------------
kswapd0/111 is trying to acquire lock:
ffff88801eae4610 (sb_internal#3){.+.+}-{0:0}, at: btrfs_commit_inode_delayed_inode+0x110/0x330 fs/btrfs/delayed-inode.c:1275
but task is already holding lock:
ffffffff8dd3a9a0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0xa88/0x1970 mm/vmscan.c:6924
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (fs_reclaim){+.+.}-{0:0}:
__fs_reclaim_acquire mm/page_alloc.c:3783 [inline]
fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3797
might_alloc include/linux/sched/mm.h:334 [inline]
slab_pre_alloc_hook mm/slub.c:3890 [inline]
slab_alloc_node mm/slub.c:3980 [inline]
kmem_cache_alloc_lru_noprof+0x58/0x2f0 mm/slub.c:4019
btrfs_alloc_inode+0x118/0xb20 fs/btrfs/inode.c:8411
alloc_inode+0x5d/0x230 fs/inode.c:261
iget5_locked fs/inode.c:1235 [inline]
iget5_locked+0x1c9/0x2c0 fs/inode.c:1228
btrfs_iget_locked fs/btrfs/inode.c:5590 [inline]
btrfs_iget_path fs/btrfs/inode.c:5607 [inline]
btrfs_iget+0xfb/0x230 fs/btrfs/inode.c:5636
create_reloc_inode+0x403/0x820 fs/btrfs/relocation.c:3911
btrfs_relocate_block_group+0x471/0xe60 fs/btrfs/relocation.c:4114
btrfs_relocate_chunk+0x143/0x450 fs/btrfs/volumes.c:3373
__btrfs_balance fs/btrfs/volumes.c:4157 [inline]
btrfs_balance+0x211a/0x3f00 fs/btrfs/volumes.c:4534
btrfs_ioctl_balance fs/btrfs/ioctl.c:3675 [inline]
btrfs_ioctl+0x12ed/0x8290 fs/btrfs/ioctl.c:4742
__do_compat_sys_ioctl+0x2c3/0x330 fs/ioctl.c:1007
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
-> #2 (btrfs_trans_num_extwriters){++++}-{0:0}:
join_transaction+0x164/0xf40 fs/btrfs/transaction.c:315
start_transaction+0x427/0x1a70 fs/btrfs/transaction.c:700
btrfs_rebuild_free_space_tree+0xaa/0x480 fs/btrfs/free-space-tree.c:1323
btrfs_start_pre_rw_mount+0x218/0xf60 fs/btrfs/disk-io.c:2999
open_ctree+0x41ab/0x52e0 fs/btrfs/disk-io.c:3554
btrfs_fill_super fs/btrfs/super.c:946 [inline]
btrfs_get_tree_super fs/btrfs/super.c:1863 [inline]
btrfs_get_tree+0x11e9/0x1b90 fs/btrfs/super.c:2089
vfs_get_tree+0x8f/0x380 fs/super.c:1780
fc_mount+0x16/0xc0 fs/namespace.c:1125
btrfs_get_tree_subvol fs/btrfs/super.c:2052 [inline]
btrfs_get_tree+0xa53/0x1b90 fs/btrfs/super.c:2090
vfs_get_tree+0x8f/0x380 fs/super.c:1780
do_new_mount fs/namespace.c:3352 [inline]
path_mount+0x6e1/0x1f10 fs/namespace.c:3679
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount fs/namespace.c:3875 [inline]
__ia32_sys_mount+0x295/0x320 fs/namespace.c:3875
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
-> #1 (btrfs_trans_num_writers){++++}-{0:0}:
join_transaction+0x148/0xf40 fs/btrfs/transaction.c:314
start_transaction+0x427/0x1a70 fs/btrfs/transaction.c:700
btrfs_rebuild_free_space_tree+0xaa/0x480 fs/btrfs/free-space-tree.c:1323
btrfs_start_pre_rw_mount+0x218/0xf60 fs/btrfs/disk-io.c:2999
open_ctree+0x41ab/0x52e0 fs/btrfs/disk-io.c:3554
btrfs_fill_super fs/btrfs/super.c:946 [inline]
btrfs_get_tree_super fs/btrfs/super.c:1863 [inline]
btrfs_get_tree+0x11e9/0x1b90 fs/btrfs/super.c:2089
vfs_get_tree+0x8f/0x380 fs/super.c:1780
fc_mount+0x16/0xc0 fs/namespace.c:1125
btrfs_get_tree_subvol fs/btrfs/super.c:2052 [inline]
btrfs_get_tree+0xa53/0x1b90 fs/btrfs/super.c:2090
vfs_get_tree+0x8f/0x380 fs/super.c:1780
do_new_mount fs/namespace.c:3352 [inline]
path_mount+0x6e1/0x1f10 fs/namespace.c:3679
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount fs/namespace.c:3875 [inline]
__ia32_sys_mount+0x295/0x320 fs/namespace.c:3875
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
-> #0 (sb_internal#3){.+.+}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
__sb_start_write include/linux/fs.h:1655 [inline]
sb_start_intwrite include/linux/fs.h:1838 [inline]
start_transaction+0xbc1/0x1a70 fs/btrfs/transaction.c:694
btrfs_commit_inode_delayed_inode+0x110/0x330 fs/btrfs/delayed-inode.c:1275
btrfs_evict_inode+0x960/0xe80 fs/btrfs/inode.c:5291
evict+0x2ed/0x6c0 fs/inode.c:667
iput_final fs/inode.c:1741 [inline]
iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
iput+0x5c/0x80 fs/inode.c:1757
btrfs_scan_root fs/btrfs/extent_map.c:1118 [inline]
btrfs_free_extent_maps+0xbd3/0x1320 fs/btrfs/extent_map.c:1189
super_cache_scan+0x409/0x550 fs/super.c:227
do_shrink_slab+0x44f/0x11c0 mm/shrinker.c:435
shrink_slab+0x18a/0x1310 mm/shrinker.c:662
shrink_one+0x493/0x7c0 mm/vmscan.c:4790
shrink_many mm/vmscan.c:4851 [inline]
lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951
shrink_node mm/vmscan.c:5910 [inline]
kswapd_shrink_node mm/vmscan.c:6720 [inline]
balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911
kswapd+0x5ea/0xbf0 mm/vmscan.c:7180
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
other info that might help us debug this:
Chain exists of:
sb_internal#3 --> btrfs_trans_num_extwriters --> fs_reclaim
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(fs_reclaim);
lock(btrfs_trans_num_extwriters);
lock(fs_reclaim);
rlock(sb_internal#3);
*** DEADLOCK ***
2 locks held by kswapd0/111:
#0:
ffffffff8dd3a9a0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0xa88/0x1970 mm/vmscan.c:6924
#1:
ffff88801eae40e0 (&type->s_umount_key#62){++++}-{3:3}, at: super_trylock_shared fs/super.c:562 [inline]
#1:
ffff88801eae40e0 (&type->s_umount_key#62){++++}-{3:3}, at: super_cache_scan+0x96/0x550 fs/super.c:196
stack backtrace:
CPU: 0 PID: 111 Comm: kswapd0 Not tainted
6.10.0-rc2-syzkaller-00010-g2ab795141095 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
__sb_start_write include/linux/fs.h:1655 [inline]
sb_start_intwrite include/linux/fs.h:1838 [inline]
start_transaction+0xbc1/0x1a70 fs/btrfs/transaction.c:694
btrfs_commit_inode_delayed_inode+0x110/0x330 fs/btrfs/delayed-inode.c:1275
btrfs_evict_inode+0x960/0xe80 fs/btrfs/inode.c:5291
evict+0x2ed/0x6c0 fs/inode.c:667
iput_final fs/inode.c:1741 [inline]
iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
iput+0x5c/0x80 fs/inode.c:1757
btrfs_scan_root fs/btrfs/extent_map.c:1118 [inline]
btrfs_free_extent_maps+0xbd3/0x1320 fs/btrfs/extent_map.c:1189
super_cache_scan+0x409/0x550 fs/super.c:227
do_shrink_slab+0x44f/0x11c0 mm/shrinker.c:435
shrink_slab+0x18a/0x1310 mm/shrinker.c:662
shrink_one+0x493/0x7c0 mm/vmscan.c:4790
shrink_many mm/vmscan.c:4851 [inline]
lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951
shrink_node mm/vmscan.c:5910 [inline]
kswapd_shrink_node mm/vmscan.c:6720 [inline]
balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911
kswapd+0x5ea/0xbf0 mm/vmscan.c:7180
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
So fix this by using btrfs_add_delayed_iput() so that the final iput is
delegated to the cleaner kthread.
Link: https://lore.kernel.org/linux-btrfs/000000000000892280061a344581@google.com/
Reported-by: syzbot+3dad89b3993a4b275e72@syzkaller.appspotmail.com
Fixes:
956a17d9d050 ("btrfs: add a shrinker for extent maps")
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>
Boris Burkov [Tue, 2 Jul 2024 14:31:14 +0000 (07:31 -0700)]
btrfs: fix folio refcount in __alloc_dummy_extent_buffer()
Another improper use of __folio_put() in an error path after freshly
allocating pages/folios which returns them with the refcount initialized
to 1. The refactor from __free_pages() -> __folio_put() (instead of
folio_put) removed a refcount decrement found in __free_pages() and
folio_put but absent from __folio_put().
Fixes:
13df3775efca ("btrfs: cleanup metadata page pointer usage")
CC: stable@vger.kernel.org # 6.8+
Tested-by: Ed Tomlinson <edtoml@gmail.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Boris Burkov [Tue, 2 Jul 2024 14:31:13 +0000 (07:31 -0700)]
btrfs: fix folio refcount in btrfs_do_encoded_write()
The conversion to folios switched __free_page() to __folio_put() in the
error path in btrfs_do_encoded_write().
However, this gets the page refcounting wrong. If we do hit that error
path (I reproduced by modifying btrfs_do_encoded_write to pretend to
always fail in a way that jumps to out_folios and running the fstests
case btrfs/281), then we always hit the following BUG freeing the folio:
BUG: Bad page state in process btrfs pfn:40ab0b
page: refcount:1 mapcount:0 mapping:
0000000000000000 index:0x61be5 pfn:0x40ab0b
flags: 0x5ffff0000000000(node=0|zone=2|lastcpupid=0x1ffff)
raw:
05ffff0000000000 0000000000000000 dead000000000122 0000000000000000
raw:
0000000000061be5 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: nonzero _refcount
Call Trace:
<TASK>
dump_stack_lvl+0x3d/0xe0
bad_page+0xea/0xf0
free_unref_page+0x8e1/0x900
? __mem_cgroup_uncharge+0x69/0x90
__folio_put+0xe6/0x190
btrfs_do_encoded_write+0x445/0x780
? current_time+0x25/0xd0
btrfs_do_write_iter+0x2cc/0x4b0
btrfs_ioctl_encoded_write+0x2b6/0x340
It turns out __free_page() decreases the page reference count while
__folio_put() does not. Switch __folio_put() to folio_put() which
decreases the folio reference count first.
Fixes:
400b172b8cdc ("btrfs: compression: migrate compression/decompression paths to folios")
Tested-by: Ed Tomlinson <edtoml@gmail.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Sun, 23 Jun 2024 11:50:26 +0000 (12:50 +0100)]
btrfs: fix uninitialized return value in the ref-verify tool
In the ref-verify tool, when processing the inline references of an extent
item, we may end up returning with uninitialized return value, because:
1) The 'ret' variable is not initialized if there are no inline extent
references ('ptr' == 'end' before the while loop starts);
2) If we find an extent owner inline reference we don't initialize 'ret'.
So fix these cases by initializing 'ret' to 0 when declaring the variable
and set it to -EINVAL if we find an extent owner inline references and
simple quotas are not enabled (as well as print an error message).
Reported-by: Mirsad Todorovac <mtodorovac69@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/59b40ebe-c824-457d-8b24-0bbca69d472b@gmail.com/
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Mon, 24 Jun 2024 05:40:53 +0000 (15:10 +0930)]
btrfs: always do the basic checks for btrfs_qgroup_inherit structure
[BUG]
Syzbot reports the following regression detected by KASAN:
BUG: KASAN: slab-out-of-bounds in btrfs_qgroup_inherit+0x42e/0x2e20 fs/btrfs/qgroup.c:3277
Read of size 8 at addr
ffff88814628ca50 by task syz-executor318/5171
CPU: 0 PID: 5171 Comm: syz-executor318 Not tainted
6.10.0-rc2-syzkaller-00010-g2ab795141095 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x169/0x550 mm/kasan/report.c:488
kasan_report+0x143/0x180 mm/kasan/report.c:601
btrfs_qgroup_inherit+0x42e/0x2e20 fs/btrfs/qgroup.c:3277
create_pending_snapshot+0x1359/0x29b0 fs/btrfs/transaction.c:1854
create_pending_snapshots+0x195/0x1d0 fs/btrfs/transaction.c:1922
btrfs_commit_transaction+0xf20/0x3740 fs/btrfs/transaction.c:2382
create_snapshot+0x6a1/0x9e0 fs/btrfs/ioctl.c:875
btrfs_mksubvol+0x58f/0x710 fs/btrfs/ioctl.c:1029
btrfs_mksnapshot+0xb5/0xf0 fs/btrfs/ioctl.c:1075
__btrfs_ioctl_snap_create+0x387/0x4b0 fs/btrfs/ioctl.c:1340
btrfs_ioctl_snap_create_v2+0x1f2/0x3a0 fs/btrfs/ioctl.c:1422
btrfs_ioctl+0x99e/0xc60
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcbf1992509
RSP: 002b:
00007fcbf1928218 EFLAGS:
00000246 ORIG_RAX:
0000000000000010
RAX:
ffffffffffffffda RBX:
00007fcbf1a1f618 RCX:
00007fcbf1992509
RDX:
0000000020000280 RSI:
0000000050009417 RDI:
0000000000000003
RBP:
00007fcbf1a1f610 R08:
00007ffea1298e97 R09:
0000000000000000
R10:
0000000000000000 R11:
0000000000000246 R12:
00007fcbf19eb660
R13:
00000000200002b8 R14:
00007fcbf19e60c0 R15:
0030656c69662f2e
</TASK>
And it also pinned it down to commit
b5357cb268c4 ("btrfs: qgroup: do not
check qgroup inherit if qgroup is disabled").
[CAUSE]
That offending commit skips the whole qgroup inherit check if qgroup is
not enabled.
But that also skips the very basic checks like
num_ref_copies/num_excl_copies and the structure size checks.
Meaning if a qgroup enable/disable race is happening at the background,
and we pass a btrfs_qgroup_inherit structure when the qgroup is
disabled, the check would be completely skipped.
Then at the time of transaction commitment, qgroup is re-enabled and
btrfs_qgroup_inherit() is going to use the incorrect structure and
causing the above KASAN error.
[FIX]
Make btrfs_qgroup_check_inherit() only skip the source qgroup checks.
So that even if invalid btrfs_qgroup_inherit structure is passed in, we
can still reject invalid ones no matter if qgroup is enabled or not.
Furthermore we do already have an extra safety inside
btrfs_qgroup_inherit(), which would just ignore invalid qgroup sources,
so even if we only skip the qgroup source check we're still safe.
Reported-by: syzbot+a0d1f7e26910be4dc171@syzkaller.appspotmail.com
Fixes:
b5357cb268c4 ("btrfs: qgroup: do not check qgroup inherit if qgroup is disabled")
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Jeongjun Park <aha310510@gmail.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Naohiro Aota [Thu, 20 Jun 2024 06:05:45 +0000 (15:05 +0900)]
btrfs: zoned: fix calc_available_free_space() for zoned mode
calc_available_free_space() returns the total size of metadata (or
system) block groups, which can be allocated from unallocated disk
space. The logic is wrong on zoned mode in two places.
First, the calculation of data_chunk_size is wrong. We always allocate
one zone as one chunk, and no partial allocation of a zone. So, we
should use zone_size (= data_sinfo->chunk_size) as it is.
Second, the result "avail" may not be zone aligned. Since we always
allocate one zone as one chunk on zoned mode, returning non-zone size
aligned bytes will result in less pressure on the async metadata reclaim
process.
This is serious for the nearly full state with a large zone size device.
Allowing over-commit too much will result in less async reclaim work and
end up in ENOSPC. We can align down to the zone size to avoid that.
Fixes:
cb6cbab79055 ("btrfs: adjust overcommit logic when very close to full")
CC: stable@vger.kernel.org # 6.9
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Naohiro Aota [Fri, 28 Jun 2024 04:32:24 +0000 (13:32 +0900)]
btrfs: fix adding block group to a reclaim list and the unused list during reclaim
There is a potential parallel list adding for retrying in
btrfs_reclaim_bgs_work and adding to the unused list. Since the block
group is removed from the reclaim list and it is on a relocation work,
it can be added into the unused list in parallel. When that happens,
adding it to the reclaim list will corrupt the list head and trigger
list corruption like below.
Fix it by taking fs_info->unused_bgs_lock.
[177.504][T2585409] BTRFS error (device nullb1): error relocating ch= unk
2415919104
[177.514][T2585409] list_del corruption. next->prev should be ff1100=
0344b119c0, but was
ff11000377e87c70. (next=
3Dff110002390cd9c0)
[177.529][T2585409] ------------[ cut here ]------------
[177.537][T2585409] kernel BUG at lib/list_debug.c:65!
[177.545][T2585409] Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
[177.555][T2585409] CPU: 9 PID:
2585409 Comm: kworker/u128:2 Tainted: G W 6.10.0-rc5-kts #1
[177.568][T2585409] Hardware name: Supermicro SYS-520P-WTR/X12SPW-TF, BIOS 1.2 02/14/2022
[177.579][T2585409] Workqueue: events_unbound btrfs_reclaim_bgs_work[btrfs]
[177.589][T2585409] RIP: 0010:__list_del_entry_valid_or_report.cold+0x70/0x72
[177.624][T2585409] RSP: 0018:
ff11000377e87a70 EFLAGS:
00010286
[177.633][T2585409] RAX:
000000000000006d RBX:
ff11000344b119c0 RCX:
0000000000000000
[177.644][T2585409] RDX:
000000000000006d RSI:
0000000000000008 RDI:
ffe21c006efd0f40
[177.655][T2585409] RBP:
ff110002e0509f78 R08:
0000000000000001 R09:
ffe21c006efd0f08
[177.665][T2585409] R10:
ff11000377e87847 R11:
0000000000000000 R12:
ff110002390cd9c0
[177.676][T2585409] R13:
ff11000344b119c0 R14:
ff110002e0508000 R15:
dffffc0000000000
[177.687][T2585409] FS:
0000000000000000(0000) GS:
ff11000fec880000(0000) knlGS:
0000000000000000
[177.700][T2585409] CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
[177.709][T2585409] CR2:
00007f06bc7b1978 CR3:
0000001021e86005 CR4:
0000000000771ef0
[177.720][T2585409] DR0:
0000000000000000 DR1:
0000000000000000 DR2:
0000000000000000
[177.731][T2585409] DR3:
0000000000000000 DR6:
00000000fffe0ff0 DR7:
0000000000000400
[177.742][T2585409] PKRU:
55555554
[177.748][T2585409] Call Trace:
[177.753][T2585409] <TASK>
[177.759][T2585409] ? __die_body.cold+0x19/0x27
[177.766][T2585409] ? die+0x2e/0x50
[177.772][T2585409] ? do_trap+0x1ea/0x2d0
[177.779][T2585409] ? __list_del_entry_valid_or_report.cold+0x70/0x72
[177.788][T2585409] ? do_error_trap+0xa3/0x160
[177.795][T2585409] ? __list_del_entry_valid_or_report.cold+0x70/0x72
[177.805][T2585409] ? handle_invalid_op+0x2c/0x40
[177.812][T2585409] ? __list_del_entry_valid_or_report.cold+0x70/0x72
[177.820][T2585409] ? exc_invalid_op+0x2d/0x40
[177.827][T2585409] ? asm_exc_invalid_op+0x1a/0x20
[177.834][T2585409] ? __list_del_entry_valid_or_report.cold+0x70/0x72
[177.843][T2585409] btrfs_delete_unused_bgs+0x3d9/0x14c0 [btrfs]
There is a similar retry_list code in btrfs_delete_unused_bgs(), but it is
safe, AFAICS. Since the block group was in the unused list, the used bytes
should be 0 when it was added to the unused list. Then, it checks
block_group->{used,reserved,pinned} are still 0 under the
block_group->lock. So, they should be still eligible for the unused list,
not the reclaim list.
The reason it is safe there it's because because we're holding
space_info->groups_sem in write mode.
That means no other task can allocate from the block group, so while we
are at deleted_unused_bgs() it's not possible for other tasks to
allocate and deallocate extents from the block group, so it can't be
added to the unused list or the reclaim list by anyone else.
The bug can be reproduced by btrfs/166 after a few rounds. In practice
this can be hit when relocation cannot find more chunk space and ends
with ENOSPC.
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Suggested-by: Johannes Thumshirn <Johannes.Thumshirn@wdc.com>
Fixes:
4eb4e85c4f81 ("btrfs: retry block group reclaim without infinite loop")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 20 Jun 2024 11:32:00 +0000 (12:32 +0100)]
btrfs: qgroup: fix quota root leak after quota disable failure
If during the quota disable we fail when cleaning the quota tree or when
deleting the root from the root tree, we jump to the 'out' label without
ever dropping the reference on the quota root, resulting in a leak of the
root since fs_info->quota_root is no longer pointing to the root (we have
set it to NULL just before those steps).
Fix this by always doing a btrfs_put_root() call under the 'out' label.
This is a problem that exists since qgroups were first added in 2012 by
commit
bed92eae26cc ("Btrfs: qgroup implementation and prototypes"), but
back then we missed a kfree on the quota root and free_extent_buffer()
calls on its root and commit root nodes, since back then roots were not
yet reference counted.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Mon, 17 Jun 2024 05:48:44 +0000 (15:18 +0930)]
btrfs: scrub: handle RST lookup error correctly
[BUG]
When running btrfs/060 with forced RST feature, it would crash the
following ASSERT() inside scrub_read_endio():
ASSERT(sector_nr < stripe->nr_sectors);
Before that, we would have tree dump from
btrfs_get_raid_extent_offset(), as we failed to find the RST entry for
the range.
[CAUSE]
Inside scrub_submit_extent_sector_read() every time we allocated a new
bbio we immediately called btrfs_map_block() to make sure there was some
RST range covering the scrub target.
But if btrfs_map_block() fails, we immediately call endio for the bbio,
while the bbio is newly allocated, it's completely empty.
Then inside scrub_read_endio(), we go through the bvecs to find
the sector number (as bi_sector is no longer reliable if the bio is
submitted to lower layers).
And since the bio is empty, such bvecs iteration would not find any
sector matching the sector, and return sector_nr == stripe->nr_sectors,
triggering the ASSERT().
[FIX]
Instead of calling btrfs_map_block() after allocating a new bbio, call
btrfs_map_block() first.
Since our only objective of calling btrfs_map_block() is only to update
stripe_len, there is really no need to do that after btrfs_alloc_bio().
This new timing would avoid the problem of handling empty bbio
completely, and in fact fixes a possible race window for the old code,
where if the submission thread is the only owner of the pending_io, the
scrub would never finish (since we didn't decrease the pending_io
counter).
Although the root cause of RST lookup failure still needs to be
addressed.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Naohiro Aota [Tue, 11 Jun 2024 08:17:30 +0000 (17:17 +0900)]
btrfs: zoned: fix initial free space detection
When creating a new block group, it calls btrfs_add_new_free_space() to add
the entire block group range into the free space accounting.
__btrfs_add_free_space_zoned() checks if size == block_group->length to
detect the initial free space adding, and proceed that case properly.
However, if the zone_capacity == zone_size and the over-write speed is fast
enough, the entire zone can be over-written within one transaction. That
confuses __btrfs_add_free_space_zoned() to handle it as an initial free
space accounting. As a result, that block group becomes a strange state: 0
used bytes, 0 zone_unusable bytes, but alloc_offset == zone_capacity (no
allocation anymore).
The initial free space accounting can properly be checked by checking
alloc_offset too.
Fixes:
98173255bddd ("btrfs: zoned: calculate free space from zone capacity")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 13 Jun 2024 10:16:19 +0000 (11:16 +0100)]
btrfs: use NOFS context when getting inodes during logging and log replay
During inode logging (and log replay too), we are holding a transaction
handle and we often need to call btrfs_iget(), which will read an inode
from its subvolume btree if it's not loaded in memory and that results in
allocating an inode with GFP_KERNEL semantics at the btrfs_alloc_inode()
callback - and this may recurse into the filesystem in case we are under
memory pressure and attempt to commit the current transaction, resulting
in a deadlock since the logging (or log replay) task is holding a
transaction handle open.
Syzbot reported this with the following stack traces:
WARNING: possible circular locking dependency detected
6.10.0-rc2-syzkaller-00361-g061d1af7b030 #0 Not tainted
------------------------------------------------------
syz-executor.1/9919 is trying to acquire lock:
ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:334 [inline]
ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:3891 [inline]
ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:3981 [inline]
ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: kmem_cache_alloc_lru_noprof+0x58/0x2f0 mm/slub.c:4020
but task is already holding lock:
ffff88804b569358 (&ei->log_mutex){+.+.}-{3:3}, at: btrfs_log_inode+0x39c/0x4660 fs/btrfs/tree-log.c:6481
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&ei->log_mutex){+.+.}-{3:3}:
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752
btrfs_log_inode+0x39c/0x4660 fs/btrfs/tree-log.c:6481
btrfs_log_inode_parent+0x8cb/0x2a90 fs/btrfs/tree-log.c:7079
btrfs_log_dentry_safe+0x59/0x80 fs/btrfs/tree-log.c:7180
btrfs_sync_file+0x9c1/0xe10 fs/btrfs/file.c:1959
vfs_fsync_range+0x141/0x230 fs/sync.c:188
generic_write_sync include/linux/fs.h:2794 [inline]
btrfs_do_write_iter+0x584/0x10c0 fs/btrfs/file.c:1705
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0x6b6/0x1140 fs/read_write.c:590
ksys_write+0x12f/0x260 fs/read_write.c:643
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
-> #2 (btrfs_trans_num_extwriters){++++}-{0:0}:
join_transaction+0x164/0xf40 fs/btrfs/transaction.c:315
start_transaction+0x427/0x1a70 fs/btrfs/transaction.c:700
btrfs_commit_super+0xa1/0x110 fs/btrfs/disk-io.c:4170
close_ctree+0xcb0/0xf90 fs/btrfs/disk-io.c:4324
generic_shutdown_super+0x159/0x3d0 fs/super.c:642
kill_anon_super+0x3a/0x60 fs/super.c:1226
btrfs_kill_super+0x3b/0x50 fs/btrfs/super.c:2096
deactivate_locked_super+0xbe/0x1a0 fs/super.c:473
deactivate_super+0xde/0x100 fs/super.c:506
cleanup_mnt+0x222/0x450 fs/namespace.c:1267
task_work_run+0x14e/0x250 kernel/task_work.c:180
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
__do_fast_syscall_32+0x80/0x120 arch/x86/entry/common.c:389
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
-> #1 (btrfs_trans_num_writers){++++}-{0:0}:
__lock_release kernel/locking/lockdep.c:5468 [inline]
lock_release+0x33e/0x6c0 kernel/locking/lockdep.c:5774
percpu_up_read include/linux/percpu-rwsem.h:99 [inline]
__sb_end_write include/linux/fs.h:1650 [inline]
sb_end_intwrite include/linux/fs.h:1767 [inline]
__btrfs_end_transaction+0x5ca/0x920 fs/btrfs/transaction.c:1071
btrfs_commit_inode_delayed_inode+0x228/0x330 fs/btrfs/delayed-inode.c:1301
btrfs_evict_inode+0x960/0xe80 fs/btrfs/inode.c:5291
evict+0x2ed/0x6c0 fs/inode.c:667
iput_final fs/inode.c:1741 [inline]
iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
iput+0x5c/0x80 fs/inode.c:1757
dentry_unlink_inode+0x295/0x480 fs/dcache.c:400
__dentry_kill+0x1d0/0x600 fs/dcache.c:603
dput.part.0+0x4b1/0x9b0 fs/dcache.c:845
dput+0x1f/0x30 fs/dcache.c:835
ovl_stack_put+0x60/0x90 fs/overlayfs/util.c:132
ovl_destroy_inode+0xc6/0x190 fs/overlayfs/super.c:182
destroy_inode+0xc4/0x1b0 fs/inode.c:311
iput_final fs/inode.c:1741 [inline]
iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
iput+0x5c/0x80 fs/inode.c:1757
dentry_unlink_inode+0x295/0x480 fs/dcache.c:400
__dentry_kill+0x1d0/0x600 fs/dcache.c:603
shrink_kill fs/dcache.c:1048 [inline]
shrink_dentry_list+0x140/0x5d0 fs/dcache.c:1075
prune_dcache_sb+0xeb/0x150 fs/dcache.c:1156
super_cache_scan+0x32a/0x550 fs/super.c:221
do_shrink_slab+0x44f/0x11c0 mm/shrinker.c:435
shrink_slab_memcg mm/shrinker.c:548 [inline]
shrink_slab+0xa87/0x1310 mm/shrinker.c:626
shrink_one+0x493/0x7c0 mm/vmscan.c:4790
shrink_many mm/vmscan.c:4851 [inline]
lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951
shrink_node mm/vmscan.c:5910 [inline]
kswapd_shrink_node mm/vmscan.c:6720 [inline]
balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911
kswapd+0x5ea/0xbf0 mm/vmscan.c:7180
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
-> #0 (fs_reclaim){+.+.}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
__fs_reclaim_acquire mm/page_alloc.c:3801 [inline]
fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3815
might_alloc include/linux/sched/mm.h:334 [inline]
slab_pre_alloc_hook mm/slub.c:3891 [inline]
slab_alloc_node mm/slub.c:3981 [inline]
kmem_cache_alloc_lru_noprof+0x58/0x2f0 mm/slub.c:4020
btrfs_alloc_inode+0x118/0xb20 fs/btrfs/inode.c:8411
alloc_inode+0x5d/0x230 fs/inode.c:261
iget5_locked fs/inode.c:1235 [inline]
iget5_locked+0x1c9/0x2c0 fs/inode.c:1228
btrfs_iget_locked fs/btrfs/inode.c:5590 [inline]
btrfs_iget_path fs/btrfs/inode.c:5607 [inline]
btrfs_iget+0xfb/0x230 fs/btrfs/inode.c:5636
add_conflicting_inode fs/btrfs/tree-log.c:5657 [inline]
copy_inode_items_to_log+0x1039/0x1e30 fs/btrfs/tree-log.c:5928
btrfs_log_inode+0xa48/0x4660 fs/btrfs/tree-log.c:6592
log_new_delayed_dentries fs/btrfs/tree-log.c:6363 [inline]
btrfs_log_inode+0x27dd/0x4660 fs/btrfs/tree-log.c:6718
btrfs_log_all_parents fs/btrfs/tree-log.c:6833 [inline]
btrfs_log_inode_parent+0x22ba/0x2a90 fs/btrfs/tree-log.c:7141
btrfs_log_dentry_safe+0x59/0x80 fs/btrfs/tree-log.c:7180
btrfs_sync_file+0x9c1/0xe10 fs/btrfs/file.c:1959
vfs_fsync_range+0x141/0x230 fs/sync.c:188
generic_write_sync include/linux/fs.h:2794 [inline]
btrfs_do_write_iter+0x584/0x10c0 fs/btrfs/file.c:1705
do_iter_readv_writev+0x504/0x780 fs/read_write.c:741
vfs_writev+0x36f/0xde0 fs/read_write.c:971
do_pwritev+0x1b2/0x260 fs/read_write.c:1072
__do_compat_sys_pwritev2 fs/read_write.c:1218 [inline]
__se_compat_sys_pwritev2 fs/read_write.c:1210 [inline]
__ia32_compat_sys_pwritev2+0x121/0x1b0 fs/read_write.c:1210
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
other info that might help us debug this:
Chain exists of:
fs_reclaim --> btrfs_trans_num_extwriters --> &ei->log_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ei->log_mutex);
lock(btrfs_trans_num_extwriters);
lock(&ei->log_mutex);
lock(fs_reclaim);
*** DEADLOCK ***
7 locks held by syz-executor.1/9919:
#0:
ffff88802be20420 (sb_writers#23){.+.+}-{0:0}, at: do_pwritev+0x1b2/0x260 fs/read_write.c:1072
#1:
ffff888065c0f8f0 (&sb->s_type->i_mutex_key#33){++++}-{3:3}, at: inode_lock include/linux/fs.h:791 [inline]
#1:
ffff888065c0f8f0 (&sb->s_type->i_mutex_key#33){++++}-{3:3}, at: btrfs_inode_lock+0xc8/0x110 fs/btrfs/inode.c:385
#2:
ffff888065c0f778 (&ei->i_mmap_lock){++++}-{3:3}, at: btrfs_inode_lock+0xee/0x110 fs/btrfs/inode.c:388
#3:
ffff88802be20610 (sb_internal#4){.+.+}-{0:0}, at: btrfs_sync_file+0x95b/0xe10 fs/btrfs/file.c:1952
#4:
ffff8880546323f0 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x430/0xf40 fs/btrfs/transaction.c:290
#5:
ffff888054632418 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x430/0xf40 fs/btrfs/transaction.c:290
#6:
ffff88804b569358 (&ei->log_mutex){+.+.}-{3:3}, at: btrfs_log_inode+0x39c/0x4660 fs/btrfs/tree-log.c:6481
stack backtrace:
CPU: 2 PID: 9919 Comm: syz-executor.1 Not tainted
6.10.0-rc2-syzkaller-00361-g061d1af7b030 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
__fs_reclaim_acquire mm/page_alloc.c:3801 [inline]
fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3815
might_alloc include/linux/sched/mm.h:334 [inline]
slab_pre_alloc_hook mm/slub.c:3891 [inline]
slab_alloc_node mm/slub.c:3981 [inline]
kmem_cache_alloc_lru_noprof+0x58/0x2f0 mm/slub.c:4020
btrfs_alloc_inode+0x118/0xb20 fs/btrfs/inode.c:8411
alloc_inode+0x5d/0x230 fs/inode.c:261
iget5_locked fs/inode.c:1235 [inline]
iget5_locked+0x1c9/0x2c0 fs/inode.c:1228
btrfs_iget_locked fs/btrfs/inode.c:5590 [inline]
btrfs_iget_path fs/btrfs/inode.c:5607 [inline]
btrfs_iget+0xfb/0x230 fs/btrfs/inode.c:5636
add_conflicting_inode fs/btrfs/tree-log.c:5657 [inline]
copy_inode_items_to_log+0x1039/0x1e30 fs/btrfs/tree-log.c:5928
btrfs_log_inode+0xa48/0x4660 fs/btrfs/tree-log.c:6592
log_new_delayed_dentries fs/btrfs/tree-log.c:6363 [inline]
btrfs_log_inode+0x27dd/0x4660 fs/btrfs/tree-log.c:6718
btrfs_log_all_parents fs/btrfs/tree-log.c:6833 [inline]
btrfs_log_inode_parent+0x22ba/0x2a90 fs/btrfs/tree-log.c:7141
btrfs_log_dentry_safe+0x59/0x80 fs/btrfs/tree-log.c:7180
btrfs_sync_file+0x9c1/0xe10 fs/btrfs/file.c:1959
vfs_fsync_range+0x141/0x230 fs/sync.c:188
generic_write_sync include/linux/fs.h:2794 [inline]
btrfs_do_write_iter+0x584/0x10c0 fs/btrfs/file.c:1705
do_iter_readv_writev+0x504/0x780 fs/read_write.c:741
vfs_writev+0x36f/0xde0 fs/read_write.c:971
do_pwritev+0x1b2/0x260 fs/read_write.c:1072
__do_compat_sys_pwritev2 fs/read_write.c:1218 [inline]
__se_compat_sys_pwritev2 fs/read_write.c:1210 [inline]
__ia32_compat_sys_pwritev2+0x121/0x1b0 fs/read_write.c:1210
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7334579
Code: b8 01 10 06 03 (...)
RSP: 002b:
00000000f5f265ac EFLAGS:
00000292 ORIG_RAX:
000000000000017b
RAX:
ffffffffffffffda RBX:
0000000000000004 RCX:
00000000200002c0
RDX:
0000000000000001 RSI:
0000000000000000 RDI:
0000000000000000
RBP:
0000000000000000 R08:
0000000000000000 R09:
0000000000000000
R10:
0000000000000000 R11:
0000000000000292 R12:
0000000000000000
R13:
0000000000000000 R14:
0000000000000000 R15:
0000000000000000
Fix this by ensuring we are under a NOFS scope whenever we call
btrfs_iget() during inode logging and log replay.
Reported-by: syzbot+8576cfa84070dce4d59b@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/000000000000274a3a061abbd928@google.com/
Fixes:
712e36c5f2a7 ("btrfs: use GFP_KERNEL in btrfs_alloc_inode")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Johannes Thumshirn [Fri, 7 Jun 2024 11:27:48 +0000 (13:27 +0200)]
btrfs: zoned: allocate dummy checksums for zoned NODATASUM writes
Shin'ichiro reported that when he's running fstests' test-case
btrfs/167 on emulated zoned devices, he's seeing the following NULL
pointer dereference in 'btrfs_zone_finish_endio()':
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000011: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f]
CPU: 4 PID:
2332440 Comm: kworker/u80:15 Tainted: G W 6.10.0-rc2-kts+ #4
Hardware name: Supermicro Super Server/X11SPi-TF, BIOS 3.3 02/21/2020
Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
RIP: 0010:btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs]
RSP: 0018:
ffff88867f107a90 EFLAGS:
00010206
RAX:
dffffc0000000000 RBX:
0000000000000000 RCX:
ffffffff893e5534
RDX:
0000000000000011 RSI:
0000000000000004 RDI:
0000000000000088
RBP:
0000000000000002 R08:
0000000000000001 R09:
ffffed1081696028
R10:
ffff88840b4b0143 R11:
ffff88834dfff600 R12:
ffff88840b4b0000
R13:
0000000000020000 R14:
0000000000000000 R15:
ffff888530ad5210
FS:
0000000000000000(0000) GS:
ffff888e3f800000(0000) knlGS:
0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
CR2:
00007f87223fff38 CR3:
00000007a7c6a002 CR4:
00000000007706f0
DR0:
0000000000000000 DR1:
0000000000000000 DR2:
0000000000000000
DR3:
0000000000000000 DR6:
00000000fffe0ff0 DR7:
0000000000000400
PKRU:
55555554
Call Trace:
<TASK>
? __die_body.cold+0x19/0x27
? die_addr+0x46/0x70
? exc_general_protection+0x14f/0x250
? asm_exc_general_protection+0x26/0x30
? do_raw_read_unlock+0x44/0x70
? btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs]
btrfs_finish_one_ordered+0x5d9/0x19a0 [btrfs]
? __pfx_lock_release+0x10/0x10
? do_raw_write_lock+0x90/0x260
? __pfx_do_raw_write_lock+0x10/0x10
? __pfx_btrfs_finish_one_ordered+0x10/0x10 [btrfs]
? _raw_write_unlock+0x23/0x40
? btrfs_finish_ordered_zoned+0x5a9/0x850 [btrfs]
? lock_acquire+0x435/0x500
btrfs_work_helper+0x1b1/0xa70 [btrfs]
? __schedule+0x10a8/0x60b0
? __pfx___might_resched+0x10/0x10
process_one_work+0x862/0x1410
? __pfx_lock_acquire+0x10/0x10
? __pfx_process_one_work+0x10/0x10
? assign_work+0x16c/0x240
worker_thread+0x5e6/0x1010
? __pfx_worker_thread+0x10/0x10
kthread+0x2c3/0x3a0
? trace_irq_enable.constprop.0+0xce/0x110
? __pfx_kthread+0x10/0x10
ret_from_fork+0x31/0x70
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Enabling CONFIG_BTRFS_ASSERT revealed the following assertion to
trigger:
assertion failed: !list_empty(&ordered->list), in fs/btrfs/zoned.c:1815
This indicates, that we're missing the checksums list on the
ordered_extent. As btrfs/167 is doing a NOCOW write this is to be
expected.
Further analysis with drgn confirmed the assumption:
>>> inode = prog.crashed_thread().stack_trace()[11]['ordered'].inode
>>> btrfs_inode = drgn.container_of(inode, "struct btrfs_inode", \
"vfs_inode")
>>> print(btrfs_inode.flags)
(u32)1
As zoned emulation mode simulates conventional zones on regular devices,
we cannot use zone-append for writing. But we're only attaching dummy
checksums if we're doing a zone-append write.
So for NOCOW zoned data writes on conventional zones, also attach a
dummy checksum.
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes:
cbfce4c7fbde ("btrfs: optimize the logical to physical mapping for zoned writes")
CC: Naohiro Aota <Naohiro.Aota@wdc.com> # 6.6+
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Boris Burkov [Fri, 7 Jun 2024 19:50:14 +0000 (12:50 -0700)]
btrfs: retry block group reclaim without infinite loop
If inc_block_group_ro systematically fails (e.g. due to ETXTBUSY from
swap) or btrfs_relocate_chunk systematically fails (from lack of
space), then this worker becomes an infinite loop.
At the very least, this strands the cleaner thread, but can also result
in hung tasks/RCU stalls on PREEMPT_NONE kernels and if the
reclaim_bgs_lock mutex is not contended.
I believe the best long term fix is to manage reclaim via work queue,
where we queue up a relocation on the triggering condition and re-queue
on failure. In the meantime, this is an easy fix to apply to avoid the
immediate pain.
Fixes:
7e2718099438 ("btrfs: reinsert BGs failed to reclaim")
CC: stable@vger.kernel.org # 6.6+
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Thu, 6 Jun 2024 01:31:51 +0000 (11:01 +0930)]
btrfs: protect folio::private when attaching extent buffer folios
[BUG]
Since v6.8 there are rare kernel crashes reported by various people,
the common factor is bad page status error messages like this:
BUG: Bad page state in process kswapd0 pfn:d6e840
page: refcount:0 mapcount:0 mapping:
000000007512f4f2 index:0x2796c2c7c
pfn:0xd6e840
aops:btree_aops ino:1
flags: 0x17ffffe0000008(uptodate|node=0|zone=2|lastcpupid=0x3fffff)
page_type: 0xffffffff()
raw:
0017ffffe0000008 dead000000000100 dead000000000122 ffff88826d0be4c0
raw:
00000002796c2c7c 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: non-NULL mapping
[CAUSE]
Commit
09e6cef19c9f ("btrfs: refactor alloc_extent_buffer() to
allocate-then-attach method") changes the sequence when allocating a new
extent buffer.
Previously we always called grab_extent_buffer() under
mapping->i_private_lock, to ensure the safety on modification on
folio::private (which is a pointer to extent buffer for regular
sectorsize).
This can lead to the following race:
Thread A is trying to allocate an extent buffer at bytenr X, with 4
4K pages, meanwhile thread B is trying to release the page at X + 4K
(the second page of the extent buffer at X).
Thread A | Thread B
-----------------------------------+-------------------------------------
| btree_release_folio()
| | This is for the page at X + 4K,
| | Not page X.
| |
alloc_extent_buffer() | |- release_extent_buffer()
|- filemap_add_folio() for the | | |- atomic_dec_and_test(eb->refs)
| page at bytenr X (the first | | |
| page). | | |
| Which returned -EEXIST. | | |
| | | |
|- filemap_lock_folio() | | |
| Returned the first page locked. | | |
| | | |
|- grab_extent_buffer() | | |
| |- atomic_inc_not_zero() | | |
| | Returned false | | |
| |- folio_detach_private() | | |- folio_detach_private() for X
| |- folio_test_private() | | |- folio_test_private()
| Returned true | | | Returned true
|- folio_put() | |- folio_put()
Now there are two puts on the same folio at folio X, leading to refcount
underflow of the folio X, and eventually causing the BUG_ON() on the
page->mapping.
The condition is not that easy to hit:
- The release must be triggered for the middle page of an eb
If the release is on the same first page of an eb, page lock would kick
in and prevent the race.
- folio_detach_private() has a very small race window
It's only between folio_test_private() and folio_clear_private().
That's exactly when mapping->i_private_lock is used to prevent such race,
and commit
09e6cef19c9f ("btrfs: refactor alloc_extent_buffer() to
allocate-then-attach method") screwed that up.
At that time, I thought the page lock would kick in as
filemap_release_folio() also requires the page to be locked, but forgot
the filemap_release_folio() only locks one page, not all pages of an
extent buffer.
[FIX]
Move all the code requiring i_private_lock into
attach_eb_folio_to_filemap(), so that everything is done with proper
lock protection.
Furthermore to prevent future problems, add an extra
lockdep_assert_locked() to ensure we're holding the proper lock.
To reproducer that is able to hit the race (takes a few minutes with
instrumented code inserting delays to alloc_extent_buffer()):
#!/bin/sh
drop_caches () {
while(true); do
echo 3 > /proc/sys/vm/drop_caches
echo 1 > /proc/sys/vm/compact_memory
done
}
run_tar () {
while(true); do
for x in `seq 1 80` ; do
tar cf /dev/zero /mnt > /dev/null &
done
wait
done
}
mkfs.btrfs -f -d single -m single /dev/vda
mount -o noatime /dev/vda /mnt
# create 200,000 files, 1K each
./simoop -n 200000 -E -f 1k /mnt
drop_caches &
(run_tar)
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/linux-btrfs/CAHk-=wgt362nGfScVOOii8cgKn2LVVHeOvOA7OBwg1OwbuJQcw@mail.gmail.com/
Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Link: https://lore.kernel.org/lkml/CABXGCsPktcHQOvKTbPaTwegMExije=Gpgci5NW=hqORo-s7diA@mail.gmail.com/
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Link: https://lore.kernel.org/linux-btrfs/e8b3311c-9a75-4903-907f-fc0f7a3fe423@gmx.de/
Reported-by: syzbot+f80b066392366b4af85e@syzkaller.appspotmail.com
Fixes:
09e6cef19c9f ("btrfs: refactor alloc_extent_buffer() to allocate-then-attach method")
CC: stable@vger.kernel.org # 6.8+
CC: Chris Mason <clm@fb.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Mon, 3 Jun 2024 11:49:08 +0000 (12:49 +0100)]
btrfs: fix leak of qgroup extent records after transaction abort
Qgroup extent records are created when delayed ref heads are created and
then released after accounting extents at btrfs_qgroup_account_extents(),
called during the transaction commit path.
If a transaction is aborted we free the qgroup records by calling
btrfs_qgroup_destroy_extent_records() at btrfs_destroy_delayed_refs(),
unless we don't have delayed references. We are incorrectly assuming
that no delayed references means we don't have qgroup extents records.
We can currently have no delayed references because we ran them all
during a transaction commit and the transaction was aborted after that
due to some error in the commit path.
So fix this by ensuring we btrfs_qgroup_destroy_extent_records() at
btrfs_destroy_delayed_refs() even if we don't have any delayed references.
Reported-by: syzbot+0fecc032fa134afd49df@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/0000000000004e7f980619f91835@google.com/
Fixes:
81f7eb00ff5b ("btrfs: destroy qgroup extent records on transaction abort")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Omar Sandoval [Fri, 24 May 2024 20:58:11 +0000 (13:58 -0700)]
btrfs: fix crash on racing fsync and size-extending write into prealloc
We have been seeing crashes on duplicate keys in
btrfs_set_item_key_safe():
BTRFS critical (device vdb): slot 4 key (450 108 8192) new key (450 108 8192)
------------[ cut here ]------------
kernel BUG at fs/btrfs/ctree.c:2620!
invalid opcode: 0000 [#1] PREEMPT SMP PTI
CPU: 0 PID: 3139 Comm: xfs_io Kdump: loaded Not tainted 6.9.0 #6
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014
RIP: 0010:btrfs_set_item_key_safe+0x11f/0x290 [btrfs]
With the following stack trace:
#0 btrfs_set_item_key_safe (fs/btrfs/ctree.c:2620:4)
#1 btrfs_drop_extents (fs/btrfs/file.c:411:4)
#2 log_one_extent (fs/btrfs/tree-log.c:4732:9)
#3 btrfs_log_changed_extents (fs/btrfs/tree-log.c:4955:9)
#4 btrfs_log_inode (fs/btrfs/tree-log.c:6626:9)
#5 btrfs_log_inode_parent (fs/btrfs/tree-log.c:7070:8)
#6 btrfs_log_dentry_safe (fs/btrfs/tree-log.c:7171:8)
#7 btrfs_sync_file (fs/btrfs/file.c:1933:8)
#8 vfs_fsync_range (fs/sync.c:188:9)
#9 vfs_fsync (fs/sync.c:202:9)
#10 do_fsync (fs/sync.c:212:9)
#11 __do_sys_fdatasync (fs/sync.c:225:9)
#12 __se_sys_fdatasync (fs/sync.c:223:1)
#13 __x64_sys_fdatasync (fs/sync.c:223:1)
#14 do_syscall_x64 (arch/x86/entry/common.c:52:14)
#15 do_syscall_64 (arch/x86/entry/common.c:83:7)
#16 entry_SYSCALL_64+0xaf/0x14c (arch/x86/entry/entry_64.S:121)
So we're logging a changed extent from fsync, which is splitting an
extent in the log tree. But this split part already exists in the tree,
triggering the BUG().
This is the state of the log tree at the time of the crash, dumped with
drgn (https://github.com/osandov/drgn/blob/main/contrib/btrfs_tree.py)
to get more details than btrfs_print_leaf() gives us:
>>> print_extent_buffer(prog.crashed_thread().stack_trace()[0]["eb"])
leaf
33439744 level 0 items 72 generation 9 owner
18446744073709551610
leaf
33439744 flags 0x100000000000000
fs uuid
e5bd3946-400c-4223-8923-
190ef1f18677
chunk uuid
d58cb17e-6d02-494a-829a-
18b7d8a399da
item 0 key (450 INODE_ITEM 0) itemoff 16123 itemsize 160
generation 7 transid 9 size 8192 nbytes
8473563889606862198
block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0
sequence 204 flags 0x10(PREALLOC)
atime
1716417703.
220000000 (2024-05-22 15:41:43)
ctime
1716417704.
983333333 (2024-05-22 15:41:44)
mtime
1716417704.
983333333 (2024-05-22 15:41:44)
otime
17592186044416.
000000000 (559444-03-08 01:40:16)
item 1 key (450 INODE_REF 256) itemoff 16110 itemsize 13
index 195 namelen 3 name: 193
item 2 key (450 XATTR_ITEM
1640047104) itemoff 16073 itemsize 37
location key (0 UNKNOWN.0 0) type XATTR
transid 7 data_len 1 name_len 6
name: user.a
data a
item 3 key (450 EXTENT_DATA 0) itemoff 16020 itemsize 53
generation 9 type 1 (regular)
extent data disk byte
303144960 nr 12288
extent data offset 0 nr 4096 ram 12288
extent compression 0 (none)
item 4 key (450 EXTENT_DATA 4096) itemoff 15967 itemsize 53
generation 9 type 2 (prealloc)
prealloc data disk byte
303144960 nr 12288
prealloc data offset 4096 nr 8192
item 5 key (450 EXTENT_DATA 8192) itemoff 15914 itemsize 53
generation 9 type 2 (prealloc)
prealloc data disk byte
303144960 nr 12288
prealloc data offset 8192 nr 4096
...
So the real problem happened earlier: notice that items 4 (4k-12k) and 5
(8k-12k) overlap. Both are prealloc extents. Item 4 straddles i_size and
item 5 starts at i_size.
Here is the state of the filesystem tree at the time of the crash:
>>> root = prog.crashed_thread().stack_trace()[2]["inode"].root
>>> ret, nodes, slots = btrfs_search_slot(root, BtrfsKey(450, 0, 0))
>>> print_extent_buffer(nodes[0])
leaf
30425088 level 0 items 184 generation 9 owner 5
leaf
30425088 flags 0x100000000000000
fs uuid
e5bd3946-400c-4223-8923-
190ef1f18677
chunk uuid
d58cb17e-6d02-494a-829a-
18b7d8a399da
...
item 179 key (450 INODE_ITEM 0) itemoff 4907 itemsize 160
generation 7 transid 7 size 4096 nbytes 12288
block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0
sequence 6 flags 0x10(PREALLOC)
atime
1716417703.
220000000 (2024-05-22 15:41:43)
ctime
1716417703.
220000000 (2024-05-22 15:41:43)
mtime
1716417703.
220000000 (2024-05-22 15:41:43)
otime
1716417703.
220000000 (2024-05-22 15:41:43)
item 180 key (450 INODE_REF 256) itemoff 4894 itemsize 13
index 195 namelen 3 name: 193
item 181 key (450 XATTR_ITEM
1640047104) itemoff 4857 itemsize 37
location key (0 UNKNOWN.0 0) type XATTR
transid 7 data_len 1 name_len 6
name: user.a
data a
item 182 key (450 EXTENT_DATA 0) itemoff 4804 itemsize 53
generation 9 type 1 (regular)
extent data disk byte
303144960 nr 12288
extent data offset 0 nr 8192 ram 12288
extent compression 0 (none)
item 183 key (450 EXTENT_DATA 8192) itemoff 4751 itemsize 53
generation 9 type 2 (prealloc)
prealloc data disk byte
303144960 nr 12288
prealloc data offset 8192 nr 4096
Item 5 in the log tree corresponds to item 183 in the filesystem tree,
but nothing matches item 4. Furthermore, item 183 is the last item in
the leaf.
btrfs_log_prealloc_extents() is responsible for logging prealloc extents
beyond i_size. It first truncates any previously logged prealloc extents
that start beyond i_size. Then, it walks the filesystem tree and copies
the prealloc extent items to the log tree.
If it hits the end of a leaf, then it calls btrfs_next_leaf(), which
unlocks the tree and does another search. However, while the filesystem
tree is unlocked, an ordered extent completion may modify the tree. In
particular, it may insert an extent item that overlaps with an extent
item that was already copied to the log tree.
This may manifest in several ways depending on the exact scenario,
including an EEXIST error that is silently translated to a full sync,
overlapping items in the log tree, or this crash. This particular crash
is triggered by the following sequence of events:
- Initially, the file has i_size=4k, a regular extent from 0-4k, and a
prealloc extent beyond i_size from 4k-12k. The prealloc extent item is
the last item in its B-tree leaf.
- The file is fsync'd, which copies its inode item and both extent items
to the log tree.
- An xattr is set on the file, which sets the
BTRFS_INODE_COPY_EVERYTHING flag.
- The range 4k-8k in the file is written using direct I/O. i_size is
extended to 8k, but the ordered extent is still in flight.
- The file is fsync'd. Since BTRFS_INODE_COPY_EVERYTHING is set, this
calls copy_inode_items_to_log(), which calls
btrfs_log_prealloc_extents().
- btrfs_log_prealloc_extents() finds the 4k-12k prealloc extent in the
filesystem tree. Since it starts before i_size, it skips it. Since it
is the last item in its B-tree leaf, it calls btrfs_next_leaf().
- btrfs_next_leaf() unlocks the path.
- The ordered extent completion runs, which converts the 4k-8k part of
the prealloc extent to written and inserts the remaining prealloc part
from 8k-12k.
- btrfs_next_leaf() does a search and finds the new prealloc extent
8k-12k.
- btrfs_log_prealloc_extents() copies the 8k-12k prealloc extent into
the log tree. Note that it overlaps with the 4k-12k prealloc extent
that was copied to the log tree by the first fsync.
- fsync calls btrfs_log_changed_extents(), which tries to log the 4k-8k
extent that was written.
- This tries to drop the range 4k-8k in the log tree, which requires
adjusting the start of the 4k-12k prealloc extent in the log tree to
8k.
- btrfs_set_item_key_safe() sees that there is already an extent
starting at 8k in the log tree and calls BUG().
Fix this by detecting when we're about to insert an overlapping file
extent item in the log tree and truncating the part that would overlap.
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Fri, 17 May 2024 11:48:25 +0000 (12:48 +0100)]
btrfs: ensure fast fsync waits for ordered extents after a write failure
If a write path in COW mode fails, either before submitting a bio for the
new extents or an actual IO error happens, we can end up allowing a fast
fsync to log file extent items that point to unwritten extents.
This is because dropping the extent maps happens when completing ordered
extents, at btrfs_finish_one_ordered(), and the completion of an ordered
extent is executed in a work queue.
This can result in a fast fsync to start logging file extent items based
on existing extent maps before the ordered extents complete, therefore
resulting in a log that has file extent items that point to unwritten
extents, resulting in a corrupt file if a crash happens after and the log
tree is replayed the next time the fs is mounted.
This can happen for both direct IO writes and buffered writes.
For example consider a direct IO write, in COW mode, that fails at
btrfs_dio_submit_io() because btrfs_extract_ordered_extent() returned an
error:
1) We call btrfs_finish_ordered_extent() with the 'uptodate' parameter
set to false, meaning an error happened;
2) That results in marking the ordered extent with the BTRFS_ORDERED_IOERR
flag;
3) btrfs_finish_ordered_extent() queues the completion of the ordered
extent - so that btrfs_finish_one_ordered() will be executed later in
a work queue. That function will drop extent maps in the range when
it's executed, since the extent maps point to unwritten locations
(signaled by the BTRFS_ORDERED_IOERR flag);
4) After calling btrfs_finish_ordered_extent() we keep going down the
write path and unlock the inode;
5) After that a fast fsync starts and locks the inode;
6) Before the work queue executes btrfs_finish_one_ordered(), the fsync
task sees the extent maps that point to the unwritten locations and
logs file extent items based on them - it does not know they are
unwritten, and the fast fsync path does not wait for ordered extents
to complete, which is an intentional behaviour in order to reduce
latency.
For the buffered write case, here's one example:
1) A fast fsync begins, and it starts by flushing delalloc and waiting for
the writeback to complete by calling filemap_fdatawait_range();
2) Flushing the dellaloc created a new extent map X;
3) During the writeback some IO error happened, and at the end io callback
(end_bbio_data_write()) we call btrfs_finish_ordered_extent(), which
sets the BTRFS_ORDERED_IOERR flag in the ordered extent and queues its
completion;
4) After queuing the ordered extent completion, the end io callback clears
the writeback flag from all pages (or folios), and from that moment the
fast fsync can proceed;
5) The fast fsync proceeds sees extent map X and logs a file extent item
based on extent map X, resulting in a log that points to an unwritten
data extent - because the ordered extent completion hasn't run yet, it
happens only after the logging.
To fix this make btrfs_finish_ordered_extent() set the inode flag
BTRFS_INODE_NEEDS_FULL_SYNC in case an error happened for a COW write,
so that a fast fsync will wait for ordered extent completion.
Note that this issues of using extent maps that point to unwritten
locations can not happen for reads, because in read paths we start by
locking the extent range and wait for any ordered extents in the range
to complete before looking for extent maps.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Tue, 21 May 2024 09:57:31 +0000 (19:27 +0930)]
btrfs: re-introduce 'norecovery' mount option
Although 'norecovery' mount option was marked as deprecated for a long
time and a warning message was printed during the deprecation window,
it's still actively utilized by several projects that need a safer way
to mount a btrfs without any writes.
Furthermore this 'norecovery' mount option is supported by other major
filesystems, which makes it less clear what's our motivation to remove
it.
Re-introduce the 'norecovery' mount option, and output a message to recommend
'rescue=nologreplay' option.
Link: https://lore.kernel.org/linux-btrfs/ZkxZT0J-z0GYvfy8@gardel-login/#t
Link: https://github.com/systemd/systemd/pull/32892
Link: https://bugzilla.suse.com/show_bug.cgi?id=1222429
Reported-by: Lennart Poettering <lennart@poettering.net>
Reported-by: Jiri Slaby <jslaby@suse.com>
Fixes:
a1912f712188 ("btrfs: remove code for inode_cache and recovery mount options")
CC: stable@vger.kernel.org # 6.8+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Tue, 14 May 2024 14:36:35 +0000 (15:36 +0100)]
btrfs: fix end of tree detection when searching for data extent ref
At lookup_extent_data_ref() we are incorrectly checking if we are at the
last slot of the last leaf in the extent tree. We are returning -ENOENT
if btrfs_next_leaf() returns a value greater than 1, but btrfs_next_leaf()
never returns anything greater than 1:
1) It returns < 0 on error;
2) 0 if there is a next leaf (or a new item was added to the end of the
current leaf after releasing the path);
3) 1 if there are no more leaves (and no new items were added to the last
leaf after releasing the path).
So fix this by checking if the return value is greater than zero instead
of being greater than one.
Fixes:
1618aa3c2e01 ("btrfs: simplify return variables in lookup_extent_data_ref()")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Lu Yao [Tue, 7 May 2024 02:34:17 +0000 (10:34 +0800)]
btrfs: scrub: initialize ret in scrub_simple_mirror() to fix compilation warning
The following error message is displayed:
../fs/btrfs/scrub.c:2152:9: error: ‘ret’ may be used uninitialized
in this function [-Werror=maybe-uninitialized]"
Compiler version: gcc version: (Debian 10.2.1-6) 10.2.1
20210110
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Lu Yao <yaolu@kylinos.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Wed, 8 May 2024 10:51:07 +0000 (11:51 +0100)]
btrfs: zoned: fix use-after-free due to race with dev replace
While loading a zone's info during creation of a block group, we can race
with a device replace operation and then trigger a use-after-free on the
device that was just replaced (source device of the replace operation).
This happens because at btrfs_load_zone_info() we extract a device from
the chunk map into a local variable and then use the device while not
under the protection of the device replace rwsem. So if there's a device
replace operation happening when we extract the device and that device
is the source of the replace operation, we will trigger a use-after-free
if before we finish using the device the replace operation finishes and
frees the device.
Fix this by enlarging the critical section under the protection of the
device replace rwsem so that all uses of the device are done inside the
critical section.
CC: stable@vger.kernel.org # 6.1.x: 15c12fcc50a1: btrfs: zoned: introduce a zone_info struct in btrfs_load_block_group_zone_info
CC: stable@vger.kernel.org # 6.1.x: 09a46725cc84: btrfs: zoned: factor out per-zone logic from btrfs_load_block_group_zone_info
CC: stable@vger.kernel.org # 6.1.x: 9e0e3e74dc69: btrfs: zoned: factor out single bg handling from btrfs_load_block_group_zone_info
CC: stable@vger.kernel.org # 6.1.x: 87463f7e0250: btrfs: zoned: factor out DUP bg handling from btrfs_load_block_group_zone_info
CC: stable@vger.kernel.org # 6.1.x
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Boris Burkov [Thu, 9 May 2024 22:34:40 +0000 (15:34 -0700)]
btrfs: qgroup: fix qgroup id collision across mounts
If we delete subvolumes whose ID is the largest in the filesystem, then
unmount and mount again, then btrfs_init_root_free_objectid on the
tree_root will select a subvolid smaller than that one and thus allow
reusing it.
If we are also using qgroups (and particularly squotas) it is possible
to delete the subvol without deleting the qgroup. In that case, we will
be able to create a new subvol whose id already has a level 0 qgroup.
This will result in re-using that qgroup which would then lead to
incorrect accounting.
Fixes:
6ed05643ddb1 ("btrfs: create qgroup earlier in snapshot creation")
CC: stable@vger.kernel.org # 6.7+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Thu, 2 May 2024 20:45:58 +0000 (22:45 +0200)]
btrfs: qgroup: update rescan message levels and error codes
On filesystems without enabled quotas there's still a warning message in
the logs when rescan is called. In that case it's not a problem that
should be reported, rescan can be called unconditionally. Change the
error code to ENOTCONN which is used for 'quotas not enabled' elsewhere.
Remove message (also a warning) when rescan is called during an ongoing
rescan, this brings no useful information and the error code is
sufficient.
Change message levels to debug for now, they can be removed eventually.
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Dan Carpenter [Sat, 4 May 2024 11:38:41 +0000 (14:38 +0300)]
btrfs: qgroup: fix initialization of auto inherit array
The "i++" was accidentally left out so it just sets qgids[0] over and
over.
This can lead to unexpected problems, as the groups[1:] would be all 0,
leading to later find_qgroup_rb() unable to find a qgroup and cause
snapshot creation failure.
Fixes:
5343cd9364ea ("btrfs: qgroup: simple quota auto hierarchy for nested subvolumes")
CC: stable@vger.kernel.org # 6.7+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Matthew Wilcox (Oracle) [Sat, 20 Apr 2024 02:49:59 +0000 (03:49 +0100)]
btrfs: count super block write errors in device instead of tracking folio error state
Currently the error status of super block write is tracked in page/folio
status bit Error. For that we need to keep the reference for the whole
duration of write and wait.
Count the number of superblock writeback errors in the btrfs_device.
That means we don't need the folio to stay around until it's waited for,
and can avoid the extra call to folio_get/put.
Also remove a mention of PageError in a comment as it's the last mention
of the page Error state.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Matthew Wilcox (Oracle) [Sat, 20 Apr 2024 02:49:58 +0000 (03:49 +0100)]
btrfs: use the folio iterator in btrfs_end_super_write()
Iterate over folios instead of bvecs. Switch the order of unlock and put
to be the usual order; we know this folio can't be put until it's been
waited for, but that's fragile. Remove the calls to ClearPageUptodate /
SetPageUptodate -- if PAGE_SIZE is larger than BTRFS_SUPER_INFO_SIZE,
we'd be marking the entire folio uptodate without having actually
initialised all the bytes in the page.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Matthew Wilcox (Oracle) [Sat, 20 Apr 2024 02:49:57 +0000 (03:49 +0100)]
btrfs: convert super block writes to folio in write_dev_supers()
This is a direct conversion from pages to folios, assuming single page
folio. Also removes some calls to obsolete APIs and some hidden calls to
compound_head().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Matthew Wilcox (Oracle) [Sat, 20 Apr 2024 02:49:56 +0000 (03:49 +0100)]
btrfs: convert super block writes to folio in wait_dev_supers()
This is a direct conversion from pages to folios, assuming single page
folio. Also removes a few calls to compound_head() and calls to
obsolete APIs.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Matthew Wilcox (Oracle) [Thu, 25 Apr 2024 16:37:56 +0000 (17:37 +0100)]
bio: Export bio_add_folio_nofail to modules
Several modules use __bio_add_page() today and may need to be converted
to bio_add_folio_nofail().
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Thorsten Blum [Thu, 2 May 2024 21:26:28 +0000 (23:26 +0200)]
btrfs: remove duplicate included header from fs.h
Remove duplicate included header file linux/blkdev.h .
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 3 Apr 2024 21:29:40 +0000 (17:29 -0400)]
btrfs: add a cached state to extent_clear_unlock_delalloc
Now that we have the lock_extent tightly coupled with
extent_clear_unlock_delalloc we can add a cached state to
extent_clear_unlock_delalloc and benefit from skipping the extra lookup
when we're doing cow.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 3 Apr 2024 20:28:45 +0000 (16:28 -0400)]
btrfs: push extent lock down in submit_one_async_extent
We don't need to include the time we spend in the allocator under our
extent lock protection, move it after the allocator and make sure we
lock the extent in the error case to ensure we're not clearing these
bits without the extent lock held.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 3 Apr 2024 19:06:09 +0000 (15:06 -0400)]
btrfs: push lock_extent down in cow_file_range()
Now that we've got the extent lock pushed into cow_file_range() we can
push it further down into the allocation loop. This allows us to only
hold the extent lock during the dropping of the extent map range and
inserting the ordered extent.
This makes the error case a little trickier as we'll now have to lock
the range before clearing any of the other extent bits for the range,
but this is the error path so is less performance critical.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 3 Apr 2024 17:57:30 +0000 (13:57 -0400)]
btrfs: move can_cow_file_range_inline() outside of the extent lock
These checks aren't reliant on the extent lock. Move this up into
cow_file_range_inline(), and then update encoded writes to call this
check before calling __cow_file_range_inline(). This will allow us to
skip the extent lock if we're not able to inline the given extent.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 3 Apr 2024 17:53:57 +0000 (13:53 -0400)]
btrfs: push lock_extent into cow_file_range_inline
Now that we've pushed the lock_extent() into cow_file_range() we can
push the extent locking into cow_file_range_inline() and move the
lock_extent in cow_file_range() to after we call
cow_file_range_inline().
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Mon, 12 Feb 2024 22:07:58 +0000 (17:07 -0500)]
btrfs: push extent lock into cow_file_range
Now that cow_file_range is the only function that is called with the
range locked, push this call into cow_file_range so we can further
narrow the scope.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 3 Apr 2024 19:31:17 +0000 (15:31 -0400)]
btrfs: push extent lock into run_delalloc_cow
This is used by zoned but also as the fallback for uncompressed extents
when we fail to compress the ranges. Push the extent lock into
run_dealloc_cow(), and adjust the compression case to take the extent
lock after calling run_delalloc_cow().
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Mon, 12 Feb 2024 21:59:43 +0000 (16:59 -0500)]
btrfs: remove unlock_extent from run_delalloc_compressed
Since we immediately unlock the extent range when we enter
run_delalloc_compressed() simply move the lock_extent() down to cover
cow_file_range() and then remove the unlock_extent() from
run_delalloc_compressed.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Mon, 12 Feb 2024 21:52:53 +0000 (16:52 -0500)]
btrfs: push extent lock down in run_delalloc_nocow
run_delalloc_nocow is a little special because we use the file extents
to see if we can nocow a range. We don't actually need the protection
of the extent lock to look at the file extents at this point however.
We are currently holding the page lock for this range, so we are
protected from anybody who would simultaneously be modifying the file
extent items for this range.
* mmap() - we're holding the page lock.
* buffered writes - we're holding the page lock.
* direct writes - we're holding the page lock and direct IO has to flush
page cache before it's able to continue.
* fallocate() - all callers flush the range and wait on ordered extents
while holding the inode lock and the mmap lock, so we are again saved
by the page lock.
We want to use the extent lock to protect
1) The mapping tree for the given range.
2) The ordered extents for the given range.
3) The io_tree for the given range.
Push the extent lock down to cover these operations. In the
fallback_to_cow() case we simply lock before doing anything and rely on
the cow_file_range() helper to handle it's range properly.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Mon, 12 Feb 2024 21:27:15 +0000 (16:27 -0500)]
btrfs: adjust while loop condition in run_delalloc_nocow
We have the following pattern
while (1) {
if (cur_offset > end)
break;
}
Which is just
while (cur_offset <= end) {
...
}
so adjust the code to be more clear.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Mon, 12 Feb 2024 21:21:19 +0000 (16:21 -0500)]
btrfs: push extent lock into run_delalloc_nocow
run_delalloc_nocow is a bit special as it walks through the file extents
for the inode and determines what it can nocow and what it can't. This
is the more complicated area for extent locking, so start with this
function.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Mon, 12 Feb 2024 21:10:44 +0000 (16:10 -0500)]
btrfs: push the extent lock into btrfs_run_delalloc_range
We want to limit the scope of the extent lock to be around operations
that can change in flight. Currently we hold the extent lock through
the entire writepage operation, which isn't really necessary.
We want to protect to make sure nobody has updated DELALLOC. In
find_lock_delalloc_range we must lock the range in order to validate the
contents of our io_tree. However once we've done that we're safe to
unlock the range and continue, as we have the page lock already held for
the range.
We are protected from all operations at this point.
* mmap() - we're holding the page lock, thus are protected.
* buffered writes - again, we're protected because we take the page lock
for the first and last page in our range for buffered writes so we
won't create new delalloc ranges in this area.
* direct IO - we invalidate pagecache before attempting to write a new
area, which requires the page lock, so again are protected once we're
holding the page lock on this range.
Additionally this behavior actually already exists for compressed, we
unlock the range as soon as we start to process the async extents, and
re-lock it during compression. So this is completely safe, and makes
the locking more consistent.
Make this simple by just pushing the extent lock into
btrfs_run_delalloc_range. From there followup patches will push the
lock further down into its users.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 3 Apr 2024 17:42:45 +0000 (13:42 -0400)]
btrfs: lock extent when doing inline extent in compression
We currently don't lock the extent when we're doing a
cow_file_range_inline() for a compressed extent. This isn't a problem
necessarily, but it's inconsistent with the rest of our usage of
cow_file_range_inline(). This also leads to some extra weird logic
around whether the extent is locked or not. Fix this to lock the extent
before calling cow_file_range_inline() in compression to make it
consistent with the rest of the inline users. In future patches this
will be pushed down into the cow_file_range_inline() helper, so we're
fine with the quick and dirty locking here. This patch exists to make
the behavior change obvious.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 20 Mar 2024 21:24:13 +0000 (17:24 -0400)]
btrfs: move extent bit and page cleanup into cow_file_range_inline
We duplicate the extent cleanup for cow_file_range_inline() in the cow
and compressed case. The encoded case doesn't need to do cleanup the
same way, so rename cow_file_range_inline to __cow_file_range_inline and
then make cow_file_range_inline handle the extent cleanup appropriately,
and update the callers.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 20 Mar 2024 21:06:10 +0000 (17:06 -0400)]
btrfs: unlock all the pages with successful inline extent creation
Since
4750af3bbe5d ("btrfs: prevent extent_clear_unlock_delalloc() to
unlock page not locked by __process_pages_contig()") we have been
unlocking the locked page manually instead of via
extent_clear_unlock_delalloc() because of subpage blocksize support.
However we actually disable inline extent creation for subpage blocksize
support, so this behavior isn't necessary. Remove this code and
comment, if at some point the subpage blocksize code grows support for
inline extents this can be re-evaluated.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 20 Mar 2024 20:40:51 +0000 (16:40 -0400)]
btrfs: push all inline logic into cow_file_range
Currently we have a lot of duplicated checks of
if (start == 0 && fs_info->sectorsize == PAGE_SIZE)
cow_file_range_inline();
Instead of duplicating this check everywhere, consolidate all of the
inline extent logic into a helper which documents all of the checks and
then use that helper inside of cow_file_range_inline(). With this we
can clean up all of the calls to either unconditionally call
cow_file_range_inline(), or at least reduce the checks we're doing
before we call cow_file_range_inline();
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Wed, 3 Apr 2024 18:49:20 +0000 (14:49 -0400)]
btrfs: handle errors in btrfs_reloc_clone_csums properly
In the cow path we will clone the reloc csums for relocated data
extents, and if there's an error we already have an ordered extent and
rely on the ordered extent finishing to clean everything up.
There's a problem however, we don't mark the ordered extent with an
error, we pretend like everything was just fine. If we were at the end
of our range we won't actually bubble up this error anywhere, and we
could end up inserting an extent that doesn't have csums where it should
have them.
Fix this by adding a helper to mark the ordered extent with an error,
and then use this when we fail to lookup the csums in
btrfs_reloc_clone_csums. Use this helper in the other place where we
use the same pattern while we're here.
This will prevent us from erroneously inserting the extent that doesn't
have the required checksums.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Wed, 3 Apr 2024 00:00:06 +0000 (10:30 +1030)]
btrfs: add extra sanity checks for create_io_em()
The function create_io_em() is called before we submit an IO, to update
the in-memory extent map for the involved range.
This patch changes the following aspects:
- Does not allow BTRFS_ORDERED_NOCOW type
For real NOCOW (excluding NOCOW writes into preallocated ranges)
writes, we never call create_io_em(), as we does not need to update
the extent map at all.
So remove the sanity check allowing BTRFS_ORDERED_NOCOW type.
- Add extra sanity checks
* PREALLOC
- @block_len == len
For uncompressed writes.
* REGULAR
- @block_len == @orig_block_len == @ram_bytes == @len
We're creating a new uncompressed extent, and referring all of it.
- @orig_start == @start
We haven no offset inside the extent.
* COMPRESSED
- valid @compress_type
- @len <= @ram_bytes
This is to co-operate with encoded writes, which can cause a new
file extent referring only part of a uncompressed extent.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Tue, 2 Apr 2024 06:00:15 +0000 (16:30 +1030)]
btrfs: simplify the inline extent map creation
With the tree-checker ensuring all inline file extents starts at file
offset 0 and has a length no larger than sectorsize, we can simplify the
calculation to assigned those fixes values directly.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Tue, 2 Apr 2024 05:30:21 +0000 (16:00 +1030)]
btrfs: add extra comments on extent_map members
The extent_map structure is very critical to btrfs, as it is involved
for both read and write paths.
Unfortunately the structure is not properly explained, making it pretty
hard to understand nor to do further improvement.
This patch adds extra comments explaining the major members based on my
code reading. Hopefully we can find more members to cleanup in the
future.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Naohiro Aota [Tue, 23 Apr 2024 10:10:29 +0000 (12:10 +0200)]
btrfs: drop unused argument of calcu_metadata_size()
calcu_metadata_size() has a "reserve" argument, but the only caller always
set it to "1". The other usage (reserve = 0) is dropped by a commit
0647bf564f1e ("Btrfs: improve forever loop when doing balance relocation"),
which is more than 10 years ago. Drop the argument and simplify the code.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Anand Jain [Tue, 19 Mar 2024 14:55:33 +0000 (20:25 +0530)]
btrfs: simplify return variables in btrfs_drop_subtree()
There's another return variable wret that is only passed to ret on
error, we can simply use ret.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Anand Jain [Tue, 19 Mar 2024 14:55:31 +0000 (20:25 +0530)]
btrfs: simplify return variables in lookup_extent_data_ref()
First, drop err instead reuse ret, choose to return the error instead of
goto fail and then return the same error. Do not initialize the ret
until where it has to be initialized. Slight logic change in handling
the btrfs_search_slot() and btrfs_next_leaf() return value.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Anand Jain [Tue, 19 Mar 2024 14:55:30 +0000 (20:25 +0530)]
btrfs: rename return variables in btrfs_qgroup_rescan_worker()
Rename ret to ret2 compile and then err to ret. Also, new ret2 is found
to be localized within the 'if (trans)' statement, so move its
declaration there.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Anand Jain [Tue, 19 Mar 2024 14:55:29 +0000 (20:25 +0530)]
btrfs: drop variable err in quick_update_accounting()
In quick_update_accounting() err is used as 2nd return value, which could
be achieved just with ret.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Anand Jain [Tue, 19 Mar 2024 14:55:23 +0000 (20:25 +0530)]
btrfs: reuse ret instead of err in relocate_tree_blocks()
Coding style fixes the function relocate_tree_blocks(). After the fix,
ret is the return value variable.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Anand Jain [Tue, 19 Mar 2024 14:55:22 +0000 (20:25 +0530)]
btrfs: rename err and ret to ret in build_backref_tree()
Code style fix in the function build_backref_tree(). Drop the ret
initialization 0, as we don't need 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>
Anand Jain [Tue, 19 Mar 2024 14:55:21 +0000 (20:25 +0530)]
btrfs: rename werr and err to ret in __btrfs_wait_marked_extents()
Rename the function's local return variables err and werr to ret.
Also, align the variable declarations with the other declarations in
the function for better function space alignment.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Anand Jain [Tue, 19 Mar 2024 14:55:20 +0000 (20:25 +0530)]
btrfs: rename werr and err to ret in btrfs_write_marked_extents()
Rename the function's local variable werr and err to ret.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Anand Jain [Tue, 16 Apr 2024 02:06:58 +0000 (10:06 +0800)]
btrfs: report filemap_fdata<write|wait>_range() error
In the function btrfs_write_marked_extents() and in __btrfs_wait_marked_extents()
return the actual error if when filemap_fdata<write|wait>_range() fails.
Suggested-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Wed, 17 Apr 2024 22:47:13 +0000 (00:47 +0200)]
btrfs: use btrfs_is_testing() everywhere
There are open coded tests of BTRFS_FS_STATE_DUMMY_FS_INFO and we have a
wrapper for that that's a compile-time constant when self-tests are not
built in. As this is only for development we can save some bytes and
conditions on release configs by using the helper in the remaining
cases.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Wed, 17 Apr 2024 15:06:13 +0000 (16:06 +0100)]
btrfs: initialize delayed inodes xarray without GFP_ATOMIC
There's no need to initialize the delayed inodes xarray with a GFP_ATOMIC
flag because that actually does nothing on the xarray operations. That was
needed for radix trees, but for xarrays the allocation flags are passed as
the last argument to xa_store() (which we are using correctly).
So initialize the delayed inodes xarray with a simple xa_init().
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Tue, 16 Apr 2024 19:52:30 +0000 (20:52 +0100)]
btrfs: make try_release_extent_mapping() return a bool
Currently try_release_extent_mapping() as an int return type, but we
use it as a boolean. Its only caller, the release folio callback, also
returns a boolean which corresponds to try_release_extent_mapping()'s
return value. So change its return value type to bool as well as its
helper try_release_extent_state().
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Tue, 16 Apr 2024 14:34:51 +0000 (15:34 +0100)]
btrfs: be better releasing extent maps at try_release_extent_mapping()
At try_release_extent_mapping(), called during the release folio callback
(btrfs_release_folio() callchain), we don't release any extent maps in the
range if the GFP flags don't allow blocking. This behaviour is exaggerated
because:
1) Both searching for extent maps and removing them are not blocking
operations. The only thing that it is the cond_resched() call at the
end of the loop that searches for and removes extent maps;
2) We currently only operate on a single page, so for the case where
block size matches the page size, we can only have one extent map,
and for the case where the block size is smaller than the page size,
we can have at most 16 extent maps.
So it's very unlikely the cond_resched() call will ever block even in the
block size smaller than page size scenario.
So instead of not removing any extent maps at all in case the GFP glags
don't allow blocking, keep removing extent maps while we don't need to
reschedule. This makes it safe for the subpage case and for a future
where we can process folios with a size larger than a page.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Tue, 16 Apr 2024 14:19:03 +0000 (15:19 +0100)]
btrfs: remove i_size restriction at try_release_extent_mapping()
Currently we don't attempt to release extent maps if the inode has an
i_size that is not greater than 16M. This condition was added way back
in 2008 by commit
70dec8079d78 ("Btrfs: extent_io and extent_state
optimizations"), without any explanation about it. A quick chat with
Chris on slack revealed that the goal was probably to release the extent
maps for small files only when closing the inode. This however can be
harmful in case we have tons of such files being kept open for very long
periods of time, since we will consume more and more pages for extent
maps.
So remove the condition.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Tue, 16 Apr 2024 14:13:03 +0000 (15:13 +0100)]
btrfs: use btrfs_get_fs_generation() at try_release_extent_mapping()
Nowadays we have the btrfs_get_fs_generation() to get the current
generation of the filesystem, so there's no need anymore to lock the
transaction spinlock to read it.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Tue, 16 Apr 2024 14:07:13 +0000 (15:07 +0100)]
btrfs: rename some variables at try_release_extent_mapping()
Rename the following variables:
1) "btrfs_inode" to "inode", because it's shorter to type and clear, and
we don't have a VFS inode here as well, so there's no confusion;
2) "tree" to "io_tree", to be clear which tree we are dealing with, since
we use 2 different trees in the function;
3) "map" to "extent_tree" since "map" gives the idea we are dealing with
an extent map for example, but we are dealing with the inode's extent
tree (the tree which stores extent maps).
These also make the next patches simpler.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Tue, 9 Apr 2024 16:07:32 +0000 (17:07 +0100)]
btrfs: add tracepoints for extent map shrinker events
Add some tracepoints for the extent map shrinker to help debug and analyse
main events. These have proved useful during development of the shrinker.
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>
Filipe Manana [Tue, 9 Apr 2024 15:41:05 +0000 (16:41 +0100)]
btrfs: update comment for btrfs_set_inode_full_sync() about locking
Nowadays we have a lock used to synchronize mmap writes with reflink and
fsync operations (struct btrfs_inode::i_mmap_lock), so update the comment
for btrfs_set_inode_full_sync() to mention that it can also be called
while holding that mmap lock. Besides being a valid alternative to the
inode's VFS lock, we already have the extent map shrinker using that mmap
lock 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>
Filipe Manana [Mon, 15 Apr 2024 16:09:26 +0000 (17:09 +0100)]
btrfs: add a shrinker for extent maps
Extent maps are used either to represent existing file extent items, or to
represent new extents that are going to be written and the respective file
extent items are created when the ordered extent completes.
We currently don't have any limit for how many extent maps we can have,
neither per inode nor globally. Most of the time this not too noticeable
because extent maps are removed in the following situations:
1) When evicting an inode;
2) When releasing folios (pages) through the btrfs_release_folio() address
space operation callback.
However we won't release extent maps in the folio range if the folio is
either dirty or under writeback or if the inode's i_size is less than
or equals to 16M (see try_release_extent_mapping(). This 16M i_size
constraint was added back in 2008 with commit
70dec8079d78 ("Btrfs:
extent_io and extent_state optimizations"), but there's no explanation
about why we have it or why the 16M value.
This means that for buffered IO we can reach an OOM situation due to too
many extent maps if either of the following happens:
1) There's a set of tasks constantly doing IO on many files with a size
not larger than 16M, specially if they keep the files open for very
long periods, therefore preventing inode eviction.
This requires a really high number of such files, and having many non
mergeable extent maps (due to random 4K writes for example) and a
machine with very little memory;
2) There's a set tasks constantly doing random write IO (therefore
creating many non mergeable extent maps) on files and keeping them
open for long periods of time, so inode eviction doesn't happen and
there's always a lot of dirty pages or pages under writeback,
preventing btrfs_release_folio() from releasing the respective extent
maps.
This second case was actually reported in the thread pointed by the Link
tag below, and it requires a very large file under heavy IO and a machine
with very little amount of RAM, which is probably hard to happen in
practice in a real world use case.
However when using direct IO this is not so hard to happen, because the
page cache is not used, and therefore btrfs_release_folio() is never
called. Which means extent maps are dropped only when evicting the inode,
and that means that if we have tasks that keep a file descriptor open and
keep doing IO on a very large file (or files), we can exhaust memory due
to an unbounded amount of extent maps. This is especially easy to happen
if we have a huge file with millions of small extents and their extent
maps are not mergeable (non contiguous offsets and disk locations).
This was reported in that thread with the following fio test:
$ cat test.sh
#!/bin/bash
DEV=/dev/sdj
MNT=/mnt/sdj
MOUNT_OPTIONS="-o ssd"
MKFS_OPTIONS=""
cat <<EOF > /tmp/fio-job.ini
[global]
name=fio-rand-write
filename=$MNT/fio-rand-write
rw=randwrite
bs=4K
direct=1
numjobs=16
fallocate=none
time_based
runtime=90000
[file1]
size=300G
ioengine=libaio
iodepth=16
EOF
umount $MNT &> /dev/null
mkfs.btrfs -f $MKFS_OPTIONS $DEV
mount $MOUNT_OPTIONS $DEV $MNT
fio /tmp/fio-job.ini
umount $MNT
Monitoring the btrfs_extent_map slab while running the test with:
$ watch -d -n 1 'cat /sys/kernel/slab/btrfs_extent_map/objects \
/sys/kernel/slab/btrfs_extent_map/total_objects'
Shows the number of active and total extent maps skyrocketing to tens of
millions, and on systems with a short amount of memory it's easy and quick
to get into an OOM situation, as reported in that thread.
So to avoid this issue add a shrinker that will remove extents maps, as
long as they are not pinned, and takes proper care with any concurrent
fsync to avoid missing extents (setting the full sync flag while in the
middle of a fast fsync). This shrinker is triggered through the callbacks
nr_cached_objects and free_cached_objects of struct super_operations.
The shrinker will iterate over all roots and over all inodes of each
root, and keeps track of the last scanned root and inode, so that the
next time it runs, it starts from that root and from the next inode.
This is similar to what xfs does for its inode reclaim (implements those
callbacks, and cycles through inodes by starting from where it ended
last time).
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>
Filipe Manana [Fri, 22 Mar 2024 18:02:59 +0000 (18:02 +0000)]
btrfs: add a global per cpu counter to track number of used extent maps
Add a per cpu counter that tracks the total number of extent maps that are
in extent trees of inodes that belong to fs trees. This is going to be
used in an upcoming change that adds a shrinker for extent maps. Only
extent maps for fs trees are considered, because for special trees such as
the data relocation tree we don't want to evict their extent maps which
are critical for the relocation to work, and since those are limited, it's
not a concern to have them in memory during the relocation of a block
group. Another case are extent maps for free space cache inodes, which
must always remain in memory, but those are limited (there's only one per
free space cache inode, which means one per block group).
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>
Filipe Manana [Thu, 11 Apr 2024 10:32:14 +0000 (11:32 +0100)]
btrfs: pass the extent map tree's inode to try_merge_map()
Extent maps are always associated to an inode's extent map tree, so
there's no need to pass the extent map tree explicitly to try_merge_map().
In order to facilitate an upcoming change that adds a shrinker for extent
maps, change try_merge_map() to receive the inode instead of its extent
map tree.
Reviewed-by: Qu Wenruo <wqu@suse.com>
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>
Filipe Manana [Thu, 11 Apr 2024 10:29:17 +0000 (11:29 +0100)]
btrfs: pass the extent map tree's inode to setup_extent_mapping()
Extent maps are always associated to an inode's extent map tree, so
there's no need to pass the extent map tree explicitly to
setup_extent_mapping().
In order to facilitate an upcoming change that adds a shrinker for extent
maps, change setup_extent_mapping() to receive the inode instead of its
extent map tree.
Reviewed-by: Qu Wenruo <wqu@suse.com>
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>
Filipe Manana [Thu, 21 Mar 2024 16:07:26 +0000 (16:07 +0000)]
btrfs: pass the extent map tree's inode to replace_extent_mapping()
Extent maps are always associated to an inode's extent map tree, so
there's no need to pass the extent map tree explicitly to
replace_extent_mapping().
In order to facilitate an upcoming change that adds a shrinker for extent
maps, change replace_extent_mapping() to receive the inode instead of its
extent map tree.
Reviewed-by: Qu Wenruo <wqu@suse.com>
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>
Filipe Manana [Thu, 21 Mar 2024 15:08:38 +0000 (15:08 +0000)]
btrfs: pass the extent map tree's inode to remove_extent_mapping()
Extent maps are always associated to an inode's extent map tree, so
there's no need to pass the extent map tree explicitly to
remove_extent_mapping().
In order to facilitate an upcoming change that adds a shrinker for extent
maps, change remove_extent_mapping() to receive the inode instead of its
extent map tree.
Reviewed-by: Qu Wenruo <wqu@suse.com>
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>
Filipe Manana [Thu, 21 Mar 2024 11:34:55 +0000 (11:34 +0000)]
btrfs: pass the extent map tree's inode to clear_em_logging()
Extent maps are always associated to an inode's extent map tree, so
there's no need to pass the extent map tree explicitly to
clear_em_logging().
In order to facilitate an upcoming change that adds a shrinker for extent
maps, change clear_em_logging() to receive the inode instead of its extent
map tree.
Reviewed-by: Qu Wenruo <wqu@suse.com>
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>
Filipe Manana [Wed, 17 Jan 2024 11:54:39 +0000 (11:54 +0000)]
btrfs: pass the extent map tree's inode to add_extent_mapping()
Extent maps are always added to an inode's extent map tree, so there's no
need to pass the extent map tree explicitly to add_extent_mapping().
In order to facilitate an upcoming change that adds a shrinker for extent
maps, change add_extent_mapping() to receive the inode instead of its
extent map tree.
Reviewed-by: Qu Wenruo <wqu@suse.com>
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>
Josef Bacik [Mon, 15 Apr 2024 20:16:23 +0000 (16:16 -0400)]
btrfs: change root->root_key.objectid to btrfs_root_id()
A comment from Filipe on one of my previous cleanups brought my
attention to a new helper we have for getting the root id of a root,
which makes it easier to read in the code.
The changes where made with the following Coccinelle semantic patch:
// <smpl>
@@
expression E,E1;
@@
(
E->root_key.objectid = E1
|
- E->root_key.objectid
+ btrfs_root_id(E)
)
// </smpl>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor style fixups ]
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Sun, 14 Apr 2024 05:42:43 +0000 (05:42 +0000)]
btrfs: set start on clone before calling copy_extent_buffer_full
Our subpage testing started hanging on generic/560 and I bisected it
down to
1cab1375ba6d ("btrfs: reuse cloned extent buffer during
fiemap to avoid re-allocations"). This is subtle because we use
eb->start to figure out where in the folio we're copying to when we're
subpage, as our ->start may refer to an area inside of the folio.
For example, assume a 16K page size machine with a 4K node size, and
assume that we already have a cloned extent buffer when we cloned the
previous search.
copy_extent_buffer_full() will do the following when copying the extent
buffer path->nodes[0] (src) into cloned (dest):
src->start = 8k; // this is the new leaf we're cloning
cloned->start = 4k; // this is left over from the previous clone
src_addr = folio_address(src->folios[0]);
dest_addr = folio_address(dest->folios[0]);
memcpy(dest_addr + get_eb_offset_in_folio(dst, 0),
src_addr + get_eb_offset_in_folio(src, 0), src->len);
Now get_eb_offset_in_folio() is where the problems occur, because for
sub-pagesize blocksize we can have multiple eb's per folio, the code for
this is as follows
size_t get_eb_offset_in_folio(eb, offset) {
return (eb->start + offset & (folio_size(eb->folio[0]) - 1));
}
So in the above example we are copying into offset 4K inside the folio.
However once we update cloned->start to 8K to match the src the math for
get_eb_offset_in_folio() changes, and any subsequent reads (i.e.
btrfs_item_key_to_cpu()) will start reading from the offset 8K instead
of 4K where we copied to, giving us garbage.
Fix this by setting start before we co copy_extent_buffer_full() to make
sure that we're copying into the same offset inside of the folio that we
will read from later.
All other sites of copy_extent_buffer_full() are correct because we
either set ->start beforehand or we simply don't change it in the case
of the tree-log usage.
With this fix we now pass generic/560 on our subpage tests.
Fixes:
1cab1375ba6d ("btrfs: reuse cloned extent buffer during fiemap to avoid re-allocations")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Sat, 13 Apr 2024 04:11:22 +0000 (00:11 -0400)]
btrfs: replace btrfs_delayed_*_ref with btrfs_*_ref
Now that these two structs are the same, move the btrfs_data_ref and
btrfs_tree_ref up and use these in the btrfs_delayed_ref_node. Then
remove the btrfs_delayed_*_ref structs.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Sat, 13 Apr 2024 04:09:03 +0000 (00:09 -0400)]
btrfs: remove the btrfs_delayed_ref_node container helpers
Now that we don't use these helpers anywhere, remove them.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Sat, 13 Apr 2024 04:07:06 +0000 (00:07 -0400)]
btrfs: stop referencing btrfs_delayed_tree_ref directly
We only ever need to use this to get the level of the tree block ref, so
use the btrfs_delayed_ref_owner() helper, which returns the level for
the given reference.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Sat, 13 Apr 2024 03:53:49 +0000 (23:53 -0400)]
btrfs: stop referencing btrfs_delayed_data_ref directly
Now that most of our elements are inside of btrfs_delayed_ref_node
directly and we have helpers for the delayed_data_ref bits, go ahead and
remove all direct usage of btrfs_delayed_data_ref and use the helpers
where needed.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Sat, 13 Apr 2024 03:43:46 +0000 (23:43 -0400)]
btrfs: make the insert backref helpers take a btrfs_delayed_ref_node
We don't need to pass in all the elements for the backrefs as function
arguments, simply pass through the btrfs_delayed_ref_node and then
extract the values we need from that.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Sat, 13 Apr 2024 03:34:48 +0000 (23:34 -0400)]
btrfs: drop unnecessary arguments from __btrfs_free_extent
We have all the information we need in our btrfs_delayed_ref_node, which
we already pass into __btrfs_free_extent. Drop the extra arguments and
just extract the values from btrfs_delayed_ref_node.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Sat, 13 Apr 2024 03:27:49 +0000 (23:27 -0400)]
btrfs: make __btrfs_inc_extent_ref take a btrfs_delayed_ref_node
We're just extracting the values from btrfs_delayed_ref_node and passing
them through, simply pass the btrfs_delayed_ref_node into
__btrfs_inc_extent_ref and shrink the function arguments.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Sat, 13 Apr 2024 03:01:38 +0000 (23:01 -0400)]
btrfs: rename btrfs_data_ref->ino to ->objectid
This is how we refer to it in the rest of the extent reference related
code, make it consistent.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Sat, 13 Apr 2024 02:57:13 +0000 (22:57 -0400)]
btrfs: move ->parent and ->ref_root into btrfs_delayed_ref_node
These two members are shared by both the tree refs and data refs, so
move them into btrfs_delayed_ref_node proper. This allows us to greatly
simplify the comparison code, as the shared refs always only sort on
parent, and the non shared refs always sort first on ref_root, and then
only data refs sort on their specific fields.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Sat, 13 Apr 2024 00:52:26 +0000 (20:52 -0400)]
btrfs: rename ->len to ->num_bytes in btrfs_ref
We consistently use ->num_bytes everywhere through the delayed ref code,
except in btrfs_ref. Rename btrfs_ref to match all the other code.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Sat, 13 Apr 2024 00:43:09 +0000 (20:43 -0400)]
btrfs: unify the btrfs_add_delayed_*_ref helpers into one helper
Now that these helpers are identical, create a helper function that
handles everything properly and strip the individual helpers down to use
just the common helper. This cleans up a significant amount of
duplicated code.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Sat, 13 Apr 2024 00:27:00 +0000 (20:27 -0400)]
btrfs: simplify delayed ref tracepoints
Now that all of the delayed ref information is in the delayed ref node,
drastically simplify the delayed ref tracepoints by simply passing in
the btrfs_delayed_ref_node and populating the tracepoints with the
values from the structure itself.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Sat, 13 Apr 2024 00:09:45 +0000 (20:09 -0400)]
btrfs: move ref specific initialization into init_delayed_ref_common
Now that the btrfs_delayed_ref_node contains a union of the data and
metadata specific information we can move the initialization into
init_delayed_ref_common and just use the btrfs_ref to initialize the
correct fields of the reference.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Sat, 13 Apr 2024 00:03:09 +0000 (20:03 -0400)]
btrfs: initialize btrfs_delayed_ref_head with btrfs_ref
We are calling init_delayed_ref_head with all of the elements from
btrfs_ref, clean this up to simply pass in the btrfs_ref and initialize
the btrfs_delayed_ref_head with the values from the btrfs_ref directly.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 12 Apr 2024 23:44:55 +0000 (19:44 -0400)]
btrfs: pass btrfs_ref to init_delayed_ref_common
We're extracting all of these values from the btrfs_ref we passed in
already, just pass the btrfs_ref through to init_delayed_ref_common and
get the values directly from the struct.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 12 Apr 2024 23:37:53 +0000 (19:37 -0400)]
btrfs: move ref_root into btrfs_ref
We have this in both btrfs_tree_ref and btrfs_data_ref, which is just
wasting space and making the code more complicated. Move this into
btrfs_ref proper and update all the call sites to do the assignment in
btrfs_ref.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 12 Apr 2024 23:17:40 +0000 (19:17 -0400)]
btrfs: do not use a function to initialize btrfs_ref
btrfs_ref currently has ->owning_root, and ->ref_root is shared between
the tree ref and data ref, so in order to move that into btrfs_ref
proper I would need to add another root parameter to the initialization
function. This function has too many arguments, and adding another root
will make it easy to make mistakes about which root goes where.
Drop the generic ref init function and statically initialize the
btrfs_ref in every usage. This makes the code easier to read because we
can see what elements we're assigning, and will make the upcoming change
moving the ref_root into the btrfs_ref more clear and less error prone
than adding a new element to the initialization function.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 12 Apr 2024 21:16:40 +0000 (17:16 -0400)]
btrfs: embed data_ref and tree_ref in btrfs_delayed_ref_node
We have been embedding btrfs_delayed_ref_node in the
btrfs_delayed_data_ref and btrfs_delayed_tree_ref, and then we have two
sets of cachep's and a variety of handling that is awkward because of
this separation.
Instead union these two members inside of btrfs_delayed_ref_node and
make that the first class object. This allows us to go down to one
cachep for our delayed ref nodes instead of two.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Fri, 12 Apr 2024 20:42:28 +0000 (16:42 -0400)]
btrfs: add a helper to get the delayed ref node from the data/tree ref
We have several different ways we refer to references throughout the
code and it's not consistent and there's a bit of duplication. In order
to clean this up I want to have one structure we use to define reference
information, and one structure we use for the delayed reference
information. Start this process by adding a helper to get from the
btrfs_delayed_data_ref/btrfs_delayed_tree_ref to the
btrfs_delayed_ref_node so that it'll make moving these structures around
simpler.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 11 Apr 2024 11:45:34 +0000 (12:45 +0100)]
btrfs: use btrfs_find_first_inode() at btrfs_prune_dentries()
Currently btrfs_prune_dentries() has open code to find the first inode in
a root with a minimum inode number. Remove that code and make it use the
helper btrfs_find_first_inode() for that task.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 11 Apr 2024 11:30:59 +0000 (12:30 +0100)]
btrfs: export find_next_inode() as btrfs_find_first_inode()
Export the relocation private helper find_next_inode() to inode.c, as this
same logic is also used at btrfs_prune_dentries() and will be used by an
upcoming change that adds an extent map shrinker. The next patch will
change btrfs_prune_dentries() to use this helper.
Reviewed-by: Qu Wenruo <wqu@suse.com>
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>
projects / linux-2.6-microblaze.git / log