Josef Bacik [Mon, 14 Apr 2025 18:51:58 +0000 (14:51 -0400)]
btrfs: adjust subpage bit start based on sectorsize
When running machines with 64k page size and a 16k nodesize we started
seeing tree log corruption in production. This turned out to be because
we were not writing out dirty blocks sometimes, so this in fact affects
all metadata writes.
When writing out a subpage EB we scan the subpage bitmap for a dirty
range. If the range isn't dirty we do
bit_start++;
to move onto the next bit. The problem is the bitmap is based on the
number of sectors that an EB has. So in this case, we have a 64k
pagesize, 16k nodesize, but a 4k sectorsize. This means our bitmap is 4
bits for every node. With a 64k page size we end up with 4 nodes per
page.
To make this easier this is how everything looks
[0 16k 32k 48k ] logical address
[0 4 8 12 ] radix tree offset
[ 64k page ] folio
[ 16k eb ][ 16k eb ][ 16k eb ][ 16k eb ] extent buffers
[ | | | | | | | | | | | | | | | | ] bitmap
Now we use all of our addressing based on fs_info->sectorsize_bits, so
as you can see the above our 16k eb->start turns into radix entry 4.
When we find a dirty range for our eb, we correctly do bit_start +=
sectors_per_node, because if we start at bit 0, the next bit for the
next eb is 4, to correspond to eb->start 16k.
However if our range is clean, we will do bit_start++, which will now
put us offset from our radix tree entries.
In our case, assume that the first time we check the bitmap the block is
not dirty, we increment bit_start so now it == 1, and then we loop
around and check again. This time it is dirty, and we go to find that
start using the following equation
start = folio_start + bit_start * fs_info->sectorsize;
so in the case above, eb->start 0 is now dirty, and we calculate start
as
0 + 1 * fs_info->sectorsize = 4096
4096 >> 12 = 1
Now we're looking up the radix tree for 1, and we won't find an eb.
What's worse is now we're using bit_start == 1, so we do bit_start +=
sectors_per_node, which is now 5. If that eb is dirty we will run into
the same thing, we will look at an offset that is not populated in the
radix tree, and now we're skipping the writeout of dirty extent buffers.
The best fix for this is to not use sectorsize_bits to address nodes,
but that's a larger change. Since this is a fs corruption problem fix
it simply by always using sectors_per_node to increment the start bit.
Fixes:
c4aec299fa8f ("btrfs: introduce submit_eb_subpage() to submit a subpage metadata page")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Penglei Jiang [Mon, 21 Apr 2025 15:40:29 +0000 (08:40 -0700)]
btrfs: fix the inode leak in btrfs_iget()
[BUG]
There is a bug report that a syzbot reproducer can lead to the following
busy inode at unmount time:
BTRFS info (device loop1): last unmount of filesystem
1680000e-3c1e-4c46-84b6-
56bd3909af50
VFS: Busy inodes after unmount of loop1 (btrfs)
------------[ cut here ]------------
kernel BUG at fs/super.c:650!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 48168 Comm: syz-executor Not tainted
6.15.0-rc2-00471-g119009db2674 #2 PREEMPT(full)
Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:generic_shutdown_super+0x2e9/0x390 fs/super.c:650
Call Trace:
<TASK>
kill_anon_super+0x3a/0x60 fs/super.c:1237
btrfs_kill_super+0x3b/0x50 fs/btrfs/super.c:2099
deactivate_locked_super+0xbe/0x1a0 fs/super.c:473
deactivate_super fs/super.c:506 [inline]
deactivate_super+0xe2/0x100 fs/super.c:502
cleanup_mnt+0x21f/0x440 fs/namespace.c:1435
task_work_run+0x14d/0x240 kernel/task_work.c:227
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:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x269/0x290 kernel/entry/common.c:218
do_syscall_64+0xd4/0x250 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
[CAUSE]
When btrfs_alloc_path() failed, btrfs_iget() directly returned without
releasing the inode already allocated by btrfs_iget_locked().
This results the above busy inode and trigger the kernel BUG.
[FIX]
Fix it by calling iget_failed() if btrfs_alloc_path() failed.
If we hit error inside btrfs_read_locked_inode(), it will properly call
iget_failed(), so nothing to worry about.
Although the iget_failed() cleanup inside btrfs_read_locked_inode() is a
break of the normal error handling scheme, let's fix the obvious bug
and backport first, then rework the error handling later.
Reported-by: Penglei Jiang <superman.xpt@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/20250421102425.44431-1-superman.xpt@gmail.com/
Fixes:
7c855e16ab72 ("btrfs: remove conditional path allocation in btrfs_read_locked_inode()")
CC: stable@vger.kernel.org # 6.13+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Penglei Jiang <superman.xpt@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Dave Chen [Tue, 15 Apr 2025 06:33:42 +0000 (14:33 +0800)]
btrfs: fix COW handling in run_delalloc_nocow()
In run_delalloc_nocow(), when the found btrfs_key's offset > cur_offset,
it indicates a gap between the current processing region and
the next file extent. The original code would directly jump to
the "must_cow" label, which increments the slot and forces a fallback
to COW. This behavior might skip an extent item and result in an
overestimated COW fallback range.
This patch modifies the logic so that when a gap is detected:
- If no COW range is already being recorded (cow_start is unset),
cow_start is set to cur_offset.
- cur_offset is then advanced to the beginning of the next extent.
- Instead of jumping to "must_cow", control flows directly to
"next_slot" so that the same extent item can be reexamined properly.
The change ensures that we accurately account for the extent gap and
avoid accidentally extending the range that needs to fallback to COW.
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Dave Chen <davechen@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Naohiro Aota [Wed, 19 Mar 2025 01:49:17 +0000 (10:49 +0900)]
btrfs: zoned: skip reporting zone for new block group
There is a potential deadlock if we do report zones in an IO context, detailed
in below lockdep report. When one process do a report zones and another process
freezes the block device, the report zones side cannot allocate a tag because
the freeze is already started. This can thus result in new block group creation
to hang forever, blocking the write path.
Thankfully, a new block group should be created on empty zones. So, reporting
the zones is not necessary and we can set the write pointer = 0 and load the
zone capacity from the block layer using bdev_zone_capacity() helper.
======================================================
WARNING: possible circular locking dependency detected
6.14.0-rc1 #252 Not tainted
------------------------------------------------------
modprobe/1110 is trying to acquire lock:
ffff888100ac83e0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: __flush_work+0x38f/0xb60
but task is already holding lock:
ffff8881205b6f20 (&q->q_usage_counter(queue)#16){++++}-{0:0}, at: sd_remove+0x85/0x130
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&q->q_usage_counter(queue)#16){++++}-{0:0}:
blk_queue_enter+0x3d9/0x500
blk_mq_alloc_request+0x47d/0x8e0
scsi_execute_cmd+0x14f/0xb80
sd_zbc_do_report_zones+0x1c1/0x470
sd_zbc_report_zones+0x362/0xd60
blkdev_report_zones+0x1b1/0x2e0
btrfs_get_dev_zones+0x215/0x7e0 [btrfs]
btrfs_load_block_group_zone_info+0x6d2/0x2c10 [btrfs]
btrfs_make_block_group+0x36b/0x870 [btrfs]
btrfs_create_chunk+0x147d/0x2320 [btrfs]
btrfs_chunk_alloc+0x2ce/0xcf0 [btrfs]
start_transaction+0xce6/0x1620 [btrfs]
btrfs_uuid_scan_kthread+0x4ee/0x5b0 [btrfs]
kthread+0x39d/0x750
ret_from_fork+0x30/0x70
ret_from_fork_asm+0x1a/0x30
-> #2 (&fs_info->dev_replace.rwsem){++++}-{4:4}:
down_read+0x9b/0x470
btrfs_map_block+0x2ce/0x2ce0 [btrfs]
btrfs_submit_chunk+0x2d4/0x16c0 [btrfs]
btrfs_submit_bbio+0x16/0x30 [btrfs]
btree_write_cache_pages+0xb5a/0xf90 [btrfs]
do_writepages+0x17f/0x7b0
__writeback_single_inode+0x114/0xb00
writeback_sb_inodes+0x52b/0xe00
wb_writeback+0x1a7/0x800
wb_workfn+0x12a/0xbd0
process_one_work+0x85a/0x1460
worker_thread+0x5e2/0xfc0
kthread+0x39d/0x750
ret_from_fork+0x30/0x70
ret_from_fork_asm+0x1a/0x30
-> #1 (&fs_info->zoned_meta_io_lock){+.+.}-{4:4}:
__mutex_lock+0x1aa/0x1360
btree_write_cache_pages+0x252/0xf90 [btrfs]
do_writepages+0x17f/0x7b0
__writeback_single_inode+0x114/0xb00
writeback_sb_inodes+0x52b/0xe00
wb_writeback+0x1a7/0x800
wb_workfn+0x12a/0xbd0
process_one_work+0x85a/0x1460
worker_thread+0x5e2/0xfc0
kthread+0x39d/0x750
ret_from_fork+0x30/0x70
ret_from_fork_asm+0x1a/0x30
-> #0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}:
__lock_acquire+0x2f52/0x5ea0
lock_acquire+0x1b1/0x540
__flush_work+0x3ac/0xb60
wb_shutdown+0x15b/0x1f0
bdi_unregister+0x172/0x5b0
del_gendisk+0x841/0xa20
sd_remove+0x85/0x130
device_release_driver_internal+0x368/0x520
bus_remove_device+0x1f1/0x3f0
device_del+0x3bd/0x9c0
__scsi_remove_device+0x272/0x340
scsi_forget_host+0xf7/0x170
scsi_remove_host+0xd2/0x2a0
sdebug_driver_remove+0x52/0x2f0 [scsi_debug]
device_release_driver_internal+0x368/0x520
bus_remove_device+0x1f1/0x3f0
device_del+0x3bd/0x9c0
device_unregister+0x13/0xa0
sdebug_do_remove_host+0x1fb/0x290 [scsi_debug]
scsi_debug_exit+0x17/0x70 [scsi_debug]
__do_sys_delete_module.isra.0+0x321/0x520
do_syscall_64+0x93/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e
other info that might help us debug this:
Chain exists of:
(work_completion)(&(&wb->dwork)->work) --> &fs_info->dev_replace.rwsem --> &q->q_usage_counter(queue)#16
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&q->q_usage_counter(queue)#16);
lock(&fs_info->dev_replace.rwsem);
lock(&q->q_usage_counter(queue)#16);
lock((work_completion)(&(&wb->dwork)->work));
*** DEADLOCK ***
5 locks held by modprobe/1110:
#0:
ffff88811f7bc108 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0x8f/0x520
#1:
ffff8881022ee0e0 (&shost->scan_mutex){+.+.}-{4:4}, at: scsi_remove_host+0x20/0x2a0
#2:
ffff88811b4c4378 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0x8f/0x520
#3:
ffff8881205b6f20 (&q->q_usage_counter(queue)#16){++++}-{0:0}, at: sd_remove+0x85/0x130
#4:
ffffffffa3284360 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xda/0xb60
stack backtrace:
CPU: 0 UID: 0 PID: 1110 Comm: modprobe Not tainted 6.14.0-rc1 #252
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x6a/0x90
print_circular_bug.cold+0x1e0/0x274
check_noncircular+0x306/0x3f0
? __pfx_check_noncircular+0x10/0x10
? mark_lock+0xf5/0x1650
? __pfx_check_irq_usage+0x10/0x10
? lockdep_lock+0xca/0x1c0
? __pfx_lockdep_lock+0x10/0x10
__lock_acquire+0x2f52/0x5ea0
? __pfx___lock_acquire+0x10/0x10
? __pfx_mark_lock+0x10/0x10
lock_acquire+0x1b1/0x540
? __flush_work+0x38f/0xb60
? __pfx_lock_acquire+0x10/0x10
? __pfx_lock_release+0x10/0x10
? mark_held_locks+0x94/0xe0
? __flush_work+0x38f/0xb60
__flush_work+0x3ac/0xb60
? __flush_work+0x38f/0xb60
? __pfx_mark_lock+0x10/0x10
? __pfx___flush_work+0x10/0x10
? __pfx_wq_barrier_func+0x10/0x10
? __pfx___might_resched+0x10/0x10
? mark_held_locks+0x94/0xe0
wb_shutdown+0x15b/0x1f0
bdi_unregister+0x172/0x5b0
? __pfx_bdi_unregister+0x10/0x10
? up_write+0x1ba/0x510
del_gendisk+0x841/0xa20
? __pfx_del_gendisk+0x10/0x10
? _raw_spin_unlock_irqrestore+0x35/0x60
? __pm_runtime_resume+0x79/0x110
sd_remove+0x85/0x130
device_release_driver_internal+0x368/0x520
? kobject_put+0x5d/0x4a0
bus_remove_device+0x1f1/0x3f0
device_del+0x3bd/0x9c0
? __pfx_device_del+0x10/0x10
__scsi_remove_device+0x272/0x340
scsi_forget_host+0xf7/0x170
scsi_remove_host+0xd2/0x2a0
sdebug_driver_remove+0x52/0x2f0 [scsi_debug]
? kernfs_remove_by_name_ns+0xc0/0xf0
device_release_driver_internal+0x368/0x520
? kobject_put+0x5d/0x4a0
bus_remove_device+0x1f1/0x3f0
device_del+0x3bd/0x9c0
? __pfx_device_del+0x10/0x10
? __pfx___mutex_unlock_slowpath+0x10/0x10
device_unregister+0x13/0xa0
sdebug_do_remove_host+0x1fb/0x290 [scsi_debug]
scsi_debug_exit+0x17/0x70 [scsi_debug]
__do_sys_delete_module.isra.0+0x321/0x520
? __pfx___do_sys_delete_module.isra.0+0x10/0x10
? __pfx_slab_free_after_rcu_debug+0x10/0x10
? kasan_save_stack+0x2c/0x50
? kasan_record_aux_stack+0xa3/0xb0
? __call_rcu_common.constprop.0+0xc4/0xfb0
? kmem_cache_free+0x3a0/0x590
? __x64_sys_close+0x78/0xd0
do_syscall_64+0x93/0x180
? lock_is_held_type+0xd5/0x130
? __call_rcu_common.constprop.0+0x3c0/0xfb0
? lockdep_hardirqs_on+0x78/0x100
? __call_rcu_common.constprop.0+0x3c0/0xfb0
? __pfx___call_rcu_common.constprop.0+0x10/0x10
? kmem_cache_free+0x3a0/0x590
? lockdep_hardirqs_on_prepare+0x16d/0x400
? do_syscall_64+0x9f/0x180
? lockdep_hardirqs_on+0x78/0x100
? do_syscall_64+0x9f/0x180
? __pfx___x64_sys_openat+0x10/0x10
? lockdep_hardirqs_on_prepare+0x16d/0x400
? do_syscall_64+0x9f/0x180
? lockdep_hardirqs_on+0x78/0x100
? do_syscall_64+0x9f/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f436712b68b
RSP: 002b:
00007ffe9f1a8658 EFLAGS:
00000206 ORIG_RAX:
00000000000000b0
RAX:
ffffffffffffffda RBX:
00005559b367fd80 RCX:
00007f436712b68b
RDX:
0000000000000000 RSI:
0000000000000800 RDI:
00005559b367fde8
RBP:
00007ffe9f1a8680 R08:
1999999999999999 R09:
0000000000000000
R10:
00007f43671a5fe0 R11:
0000000000000206 R12:
0000000000000000
R13:
00007ffe9f1a86b0 R14:
0000000000000000 R15:
0000000000000000
</TASK>
Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
CC: <stable@vger.kernel.org> # 6.13+
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Naohiro Aota [Wed, 19 Mar 2025 01:49:16 +0000 (10:49 +0900)]
block: introduce zone capacity helper
{bdev,disk}_zone_capacity() takes block_device or gendisk and sector position
and returns the zone capacity of the corresponding zone.
With that, move disk_nr_zones() and blk_zone_plug_bio() to consolidate them in
the same #ifdef block.
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Fri, 4 Apr 2025 18:19:41 +0000 (20:19 +0200)]
btrfs: tree-checker: adjust error code for header level check
The whole tree checker returns EUCLEAN, except the one check in
btrfs_verify_level_key(). This was inherited from the function that was
moved from disk-io.c in
2cac5af16537 ("btrfs: move
btrfs_verify_level_key into tree-checker.c") but this should be unified
with the rest.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Sat, 5 Apr 2025 17:40:14 +0000 (18:40 +0100)]
btrfs: fix invalid inode pointer after failure to create reloc inode
If we have a failure at create_reloc_inode(), under the 'out' label we
assign an error pointer to the 'inode' variable and then return a weird
pointer because we return the expression "&inode->vfs_inode":
static noinline_for_stack struct inode *create_reloc_inode(
const struct btrfs_block_group *group)
{
(...)
out:
(...)
if (ret) {
if (inode)
iput(&inode->vfs_inode);
inode = ERR_PTR(ret);
}
return &inode->vfs_inode;
}
This can make us return a pointer that is not an error pointer and make
the caller proceed as if an error didn't happen and later result in an
invalid memory access when dereferencing the inode pointer.
Syzbot reported reported such a case with the following stack trace:
R10:
0000000000000002 R11:
0000000000000246 R12:
0000000000000000
R13:
0000000000000000 R14:
431bde82d7b634db R15:
00007ffc55de5790
</TASK>
BTRFS info (device loop0): relocating block group
6881280 flags data|metadata
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000045: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000228-0x000000000000022f]
CPU: 0 UID: 0 PID: 5332 Comm: syz-executor215 Not tainted
6.14.0-syzkaller-13423-ga8662bcd2ff1 #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:relocate_file_extent_cluster+0xe7/0x1750 fs/btrfs/relocation.c:2971
Code: 00 74 08 (...)
RSP: 0018:
ffffc9000d3375e0 EFLAGS:
00010203
RAX:
0000000000000045 RBX:
000000000000022c RCX:
ffff888000562440
RDX:
0000000000000000 RSI:
0000000000000000 RDI:
ffff8880452db000
RBP:
ffffc9000d337870 R08:
ffffffff84089251 R09:
0000000000000000
R10:
0000000000000000 R11:
0000000000000000 R12:
dffffc0000000000
R13:
ffffffff9368a020 R14:
0000000000000394 R15:
ffff8880452db000
FS:
000055558bc7b380(0000) GS:
ffff88808c596000(0000) knlGS:
0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
CR2:
000055a7a192e740 CR3:
0000000036e2e000 CR4:
0000000000352ef0
DR0:
0000000000000000 DR1:
0000000000000000 DR2:
0000000000000000
DR3:
0000000000000000 DR6:
00000000fffe0ff0 DR7:
0000000000000400
Call Trace:
<TASK>
relocate_block_group+0xa1e/0xd50 fs/btrfs/relocation.c:3657
btrfs_relocate_block_group+0x777/0xd80 fs/btrfs/relocation.c:4011
btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3511
__btrfs_balance+0x1a93/0x25e0 fs/btrfs/volumes.c:4292
btrfs_balance+0xbde/0x10c0 fs/btrfs/volumes.c:4669
btrfs_ioctl_balance+0x3f5/0x660 fs/btrfs/ioctl.c:3586
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb4ef537dd9
Code: 28 00 00 (...)
RSP: 002b:
00007ffc55de5728 EFLAGS:
00000246 ORIG_RAX:
0000000000000010
RAX:
ffffffffffffffda RBX:
00007ffc55de5750 RCX:
00007fb4ef537dd9
RDX:
0000200000000440 RSI:
00000000c4009420 RDI:
0000000000000003
RBP:
0000000000000002 R08:
00007ffc55de54c6 R09:
00007ffc55de5770
R10:
0000000000000002 R11:
0000000000000246 R12:
0000000000000000
R13:
0000000000000000 R14:
431bde82d7b634db R15:
00007ffc55de5790
</TASK>
Modules linked in:
---[ end trace
0000000000000000 ]---
RIP: 0010:relocate_file_extent_cluster+0xe7/0x1750 fs/btrfs/relocation.c:2971
Code: 00 74 08 (...)
RSP: 0018:
ffffc9000d3375e0 EFLAGS:
00010203
RAX:
0000000000000045 RBX:
000000000000022c RCX:
ffff888000562440
RDX:
0000000000000000 RSI:
0000000000000000 RDI:
ffff8880452db000
RBP:
ffffc9000d337870 R08:
ffffffff84089251 R09:
0000000000000000
R10:
0000000000000000 R11:
0000000000000000 R12:
dffffc0000000000
R13:
ffffffff9368a020 R14:
0000000000000394 R15:
ffff8880452db000
FS:
000055558bc7b380(0000) GS:
ffff88808c596000(0000) knlGS:
0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
CR2:
000055a7a192e740 CR3:
0000000036e2e000 CR4:
0000000000352ef0
DR0:
0000000000000000 DR1:
0000000000000000 DR2:
0000000000000000
DR3:
0000000000000000 DR6:
00000000fffe0ff0 DR7:
0000000000000400
----------------
Code disassembly (best guess):
0: 00 74 08 48 add %dh,0x48(%rax,%rcx,1)
4: 89 df mov %ebx,%edi
6: e8 f8 36 24 fe call 0xfe243703
b: 48 89 9c 24 30 01 00 mov %rbx,0x130(%rsp)
12: 00
13: 4c 89 74 24 28 mov %r14,0x28(%rsp)
18: 4d 8b 76 10 mov 0x10(%r14),%r14
1c: 49 8d 9e 98 fe ff ff lea -0x168(%r14),%rbx
23: 48 89 d8 mov %rbx,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 48 89 df mov %rbx,%rdi
34: e8 ca 36 24 fe call 0xfe243703
39: 4c 8b 3b mov (%rbx),%r15
3c: 48 rex.W
3d: 8b .byte 0x8b
3e: 44 rex.R
3f: 24 .byte 0x24
So fix this by returning the error immediately.
Reported-by: syzbot+7481815bb47ef3e702e2@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/67f14ee9.050a0220.0a13.023e.GAE@google.com/
Fixes:
b204e5c7d4dc ("btrfs: make btrfs_iget() return a btrfs inode instead")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Johannes Thumshirn [Mon, 17 Mar 2025 15:04:01 +0000 (16:04 +0100)]
btrfs: zoned: return EIO on RAID1 block group write pointer mismatch
There was a bug report about a NULL pointer dereference in
__btrfs_add_free_space_zoned() that ultimately happens because a
conversion from the default metadata profile DUP to a RAID1 profile on two
disks.
The stack trace has the following signature:
BTRFS error (device sdc): zoned: write pointer offset mismatch of zones in raid1 profile
BUG: kernel NULL pointer dereference, address:
0000000000000058
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
RIP: 0010:__btrfs_add_free_space_zoned.isra.0+0x61/0x1a0
RSP: 0018:
ffffa236b6f3f6d0 EFLAGS:
00010246
RAX:
0000000000000000 RBX:
ffff96c8132f3400 RCX:
0000000000000001
RDX:
0000000010000000 RSI:
0000000000000000 RDI:
ffff96c8132f3410
RBP:
0000000010000000 R08:
0000000000000003 R09:
0000000000000000
R10:
0000000000000000 R11:
00000000ffffffff R12:
0000000000000000
R13:
ffff96c758f65a40 R14:
0000000000000001 R15:
000011aac0000000
FS:
00007fdab1cb2900(0000) GS:
ffff96e60ca00000(0000) knlGS:
0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
CR2:
0000000000000058 CR3:
00000001a05ae000 CR4:
0000000000350ef0
Call Trace:
<TASK>
? __die_body.cold+0x19/0x27
? page_fault_oops+0x15c/0x2f0
? exc_page_fault+0x7e/0x180
? asm_exc_page_fault+0x26/0x30
? __btrfs_add_free_space_zoned.isra.0+0x61/0x1a0
btrfs_add_free_space_async_trimmed+0x34/0x40
btrfs_add_new_free_space+0x107/0x120
btrfs_make_block_group+0x104/0x2b0
btrfs_create_chunk+0x977/0xf20
btrfs_chunk_alloc+0x174/0x510
? srso_return_thunk+0x5/0x5f
btrfs_inc_block_group_ro+0x1b1/0x230
btrfs_relocate_block_group+0x9e/0x410
btrfs_relocate_chunk+0x3f/0x130
btrfs_balance+0x8ac/0x12b0
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? __kmalloc_cache_noprof+0x14c/0x3e0
btrfs_ioctl+0x2686/0x2a80
? srso_return_thunk+0x5/0x5f
? ioctl_has_perm.constprop.0.isra.0+0xd2/0x120
__x64_sys_ioctl+0x97/0xc0
do_syscall_64+0x82/0x160
? srso_return_thunk+0x5/0x5f
? __memcg_slab_free_hook+0x11a/0x170
? srso_return_thunk+0x5/0x5f
? kmem_cache_free+0x3f0/0x450
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? syscall_exit_to_user_mode+0x10/0x210
? srso_return_thunk+0x5/0x5f
? do_syscall_64+0x8e/0x160
? sysfs_emit+0xaf/0xc0
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? seq_read_iter+0x207/0x460
? srso_return_thunk+0x5/0x5f
? vfs_read+0x29c/0x370
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? syscall_exit_to_user_mode+0x10/0x210
? srso_return_thunk+0x5/0x5f
? do_syscall_64+0x8e/0x160
? srso_return_thunk+0x5/0x5f
? exc_page_fault+0x7e/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fdab1e0ca6d
RSP: 002b:
00007ffeb2b60c80 EFLAGS:
00000246 ORIG_RAX:
0000000000000010
RAX:
ffffffffffffffda RBX:
0000000000000003 RCX:
00007fdab1e0ca6d
RDX:
00007ffeb2b60d80 RSI:
00000000c4009420 RDI:
0000000000000003
RBP:
00007ffeb2b60cd0 R08:
0000000000000000 R09:
0000000000000013
R10:
0000000000000000 R11:
0000000000000246 R12:
0000000000000000
R13:
00007ffeb2b6343b R14:
00007ffeb2b60d80 R15:
0000000000000001
</TASK>
CR2:
0000000000000058
---[ end trace
0000000000000000 ]---
The 1st line is the most interesting here:
BTRFS error (device sdc): zoned: write pointer offset mismatch of zones in raid1 profile
When a RAID1 block-group is created and a write pointer mismatch between
the disks in the RAID set is detected, btrfs sets the alloc_offset to the
length of the block group marking it as full. Afterwards the code expects
that a balance operation will evacuate the data in this block-group and
repair the problems.
But before this is possible, the new space of this block-group will be
accounted in the free space cache. But in __btrfs_add_free_space_zoned()
it is being checked if it is a initial creation of a block group and if
not a reclaim decision will be made. But the decision if a block-group's
free space accounting is done for an initial creation depends on if the
size of the added free space is the whole length of the block-group and
the allocation offset is 0.
But as btrfs_load_block_group_zone_info() sets the allocation offset to
the zone capacity (i.e. marking the block-group as full) this initial
decision is not met, and the space_info pointer in the 'struct
btrfs_block_group' has not yet been assigned.
Fail creation of the block group and rely on manual user intervention to
re-balance the filesystem.
Afterwards the filesystem can be unmounted, mounted in degraded mode and
the missing device can be removed after a full balance of the filesystem.
Reported-by: 西木野羰基 <yanqiyu01@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CAB_b4sBhDe3tscz=duVyhc9hNE+gu=B8CrgLO152uMyanR8BEA@mail.gmail.com/
Fixes:
b1934cd60695 ("btrfs: zoned: handle broken write pointer on zones")
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Tue, 1 Apr 2025 07:50:28 +0000 (18:20 +1030)]
btrfs: fix the ASSERT() inside GET_SUBPAGE_BITMAP()
After enabling large data folios for tests, I hit the ASSERT() inside
GET_SUBPAGE_BITMAP() where blocks_per_folio matches BITS_PER_LONG.
The ASSERT() itself is only based on the original subpage fs block size,
where we have at most 16 blocks per page, thus
"ASSERT(blocks_per_folio < BITS_PER_LONG)".
However the experimental large data folio support will set the max folio
order according to the BITS_PER_LONG, so we can have a case where a large
folio contains exactly BITS_PER_LONG blocks.
So the ASSERT() is too strict, change it to
"ASSERT(blocks_per_folio <= BITS_PER_LONG)" to avoid the false alert.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Reviewed-by: Boris Burkov <boris@bur.io>
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 [Sat, 29 Mar 2025 07:16:35 +0000 (17:46 +1030)]
btrfs: avoid page_lockend underflow in btrfs_punch_hole_lock_range()
[BUG]
When running btrfs/004 with 4K fs block size and 64K page size,
sometimes fsstress workload can take 100% CPU for a while, but not long
enough to trigger a 120s hang warning.
[CAUSE]
When such 100% CPU usage happens, btrfs_punch_hole_lock_range() is
always in the call trace.
One example when this problem happens, the function
btrfs_punch_hole_lock_range() got the following parameters:
lock_start = 4096, lockend = 20469
Then we calculate @page_lockstart by rounding up lock_start to page
boundary, which is 64K (page size is 64K).
For @page_lockend, we round down the value towards page boundary, which
result 0. Then since we need to pass an inclusive end to
filemap_range_has_page(), we subtract 1 from the rounded down value,
resulting in (u64)-1.
In the above case, the range is inside the same page, and we do not even
need to call filemap_range_has_page(), not to mention to call it with
(u64)-1 at the end.
This behavior will cause btrfs_punch_hole_lock_range() to busy loop
waiting for irrelevant range to have its pages dropped.
[FIX]
Calculate @page_lockend by just rounding down @lockend, without
decreasing the value by one. So @page_lockend will no longer overflow.
Then exit early if @page_lockend is no larger than @page_lockstart.
As it means either the range is inside the same page, or the two pages
are adjacent already.
Finally only decrease @page_lockend when calling filemap_range_has_page().
Fixes:
0528476b6ac7 ("btrfs: fix the filemap_range_has_page() call in btrfs_punch_hole_lock_range()")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Wed, 26 Mar 2025 04:11:13 +0000 (14:41 +1030)]
btrfs: subpage: access correct object when reading bitmap start in subpage_calc_start_bit()
Inside the macro, subpage_calc_start_bit(), we need to calculate the
offset to the beginning of the folio.
But we're using offset_in_page(), on systems with 4K page size and 4K fs
block size, this means we will always return offset 0 for a large folio,
causing all kinds of errors.
Fix it by using offset_in_folio() instead.
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 [Thu, 27 Mar 2025 21:29:12 +0000 (07:59 +1030)]
btrfs: remove folio order ASSERT()s in super block writeback path
[BUG]
There is a syzbot report that the ASSERT() inside write_dev_supers() got
triggered:
assertion failed: folio_order(folio) == 0, in fs/btrfs/disk-io.c:3858
------------[ cut here ]------------
kernel BUG at fs/btrfs/disk-io.c:3858!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 6730 Comm: syz-executor378 Not tainted
6.14.0-syzkaller-03565-gf6e0150b2003 #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:write_dev_supers fs/btrfs/disk-io.c:3858 [inline]
RIP: 0010:write_all_supers+0x400f/0x4090 fs/btrfs/disk-io.c:4155
Call Trace:
<TASK>
btrfs_commit_transaction+0x1eda/0x3750 fs/btrfs/transaction.c:2528
btrfs_quota_enable+0xfcc/0x21a0 fs/btrfs/qgroup.c:1226
btrfs_ioctl_quota_ctl+0x144/0x1c0 fs/btrfs/ioctl.c:3677
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5ad1f20289
</TASK>
---[ end trace
0000000000000000 ]---
[CAUSE]
Since commit
f93ee0df5139 ("btrfs: convert super block writes to folio
in write_dev_supers()") and commit
c94b7349b859 ("btrfs: convert super
block writes to folio in wait_dev_supers()"), the super block writeback
path is converted to use folio.
Since the original code is using page based interfaces, we have an
"ASSERT(folio_order(folio) == 0);" added to make sure everything is not
changed.
But the folio here is not from any btrfs inode, but from the block
device, and we have no control on the folio order in bdev, the device
can choose whatever folio size they want/need.
E.g. the bdev may even have a block size of multiple pages.
So the ASSERT() is triggered.
[FIX]
The super block writeback path has taken larger folios into
consideration, so there is no need for the ASSERT().
And since commit
bc00965dbff7 ("btrfs: count super block write errors in
device instead of tracking folio error state"), the wait path no longer
checks the folio status but only wait for the folio writeback to finish,
there is nothing requiring the ASSERT() either.
So we can remove both ASSERT()s safely now.
Reported-by: syzbot+34122898a11ab689518a@syzkaller.appspotmail.com
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Johannes Kimmel [Wed, 19 Mar 2025 21:49:00 +0000 (22:49 +0100)]
btrfs: correctly escape subvol in btrfs_show_options()
Currently, displaying the btrfs subvol mount option doesn't escape ','.
This makes parsing /proc/self/mounts and /proc/self/mountinfo
ambiguous for subvolume names that contain commas. The text after the
comma could be mistaken for another option (think "subvol=foo,ro", where
ro is actually part of the subvolumes name).
Replace the manual escape characters list with a call to
seq_show_option(). Thanks to Calvin Walton for suggesting this approach.
Fixes:
c8d3fe028f64 ("Btrfs: show subvol= and subvolid= in /proc/mounts")
CC: stable@vger.kernel.org # 5.4+
Suggested-by: Calvin Walton <calvin.walton@kepstin.ca>
Signed-off-by: Johannes Kimmel <kernel@bareminimum.eu>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Sidong Yang [Wed, 19 Mar 2025 11:24:01 +0000 (11:24 +0000)]
btrfs: ioctl: don't free iov when btrfs_encoded_read() returns -EAGAIN
Fix a bug in encoded read that mistakenly frees the iov in case
btrfs_encoded_read() returns -EAGAIN assuming the structure will be
reused. This can happen when when receiving requests concurrently, the
io_uring subsystem does not reset the data, and the last free will
happen in btrfs_uring_read_finished().
Handle the -EAGAIN error and skip freeing iov.
CC: stable@vger.kernel.org # 6.13+
Signed-off-by: Sidong Yang <sidong.yang@furiosa.ai>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Johannes Thumshirn [Mon, 17 Mar 2025 11:24:59 +0000 (12:24 +0100)]
btrfs: zoned: fix zone finishing with missing devices
If do_zone_finish() is called with a filesystem that has missing devices
(e.g. a RAID file system mounted in degraded mode) it is accessing the
btrfs_device::zone_info pointer, which will not be set if the device
in question is missing.
Check if the device is present (by checking if it has a valid block device
pointer associated) and if not, skip zone finishing for it.
Fixes:
4dcbb8ab31c1 ("btrfs: zoned: make zone finishing multi stripe capable")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.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>
Johannes Thumshirn [Mon, 17 Mar 2025 11:24:58 +0000 (12:24 +0100)]
btrfs: zoned: fix zone activation with missing devices
If btrfs_zone_activate() is called with a filesystem that has missing
devices (e.g. a RAID file system mounted in degraded mode) it is accessing
the btrfs_device::zone_info pointer, which will not be set if the device in
question is missing.
Check if the device is present (by checking if it has a valid block
device pointer associated) and if not, skip zone activation for it.
Fixes:
f9a912a3c45f ("btrfs: zoned: make zone activation multi stripe capable")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.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>
Filipe Manana [Thu, 13 Mar 2025 17:38:18 +0000 (17:38 +0000)]
btrfs: remove end_no_trans label from btrfs_log_inode_parent()
It's a pointless label as we don't have to do anything under it other
than return from the function. So remove it and directly return from the
function where we used to goto.
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, 13 Mar 2025 17:07:47 +0000 (17:07 +0000)]
btrfs: simplify condition for logging new dentries at btrfs_log_inode_parent()
There's no point in checking if the inode is a directory as
ctx->log_new_dentries is only set in case we are logging a directory down
the call chain of btrfs_log_inode(). So remove that check making the logic
more simple and while at it add a comment about why use a local variable
to track if we later need to log new dentries.
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, 13 Mar 2025 16:55:54 +0000 (16:55 +0000)]
btrfs: remove redundant else statement from btrfs_log_inode_parent()
If we don't need to log new directory dentries, there's no point in having
an else branch just to set 'ret' to zero, as it's already zero because
every time it gets a non-zero value we jump into one of the exit labels.
So remove it, which reduces source code size and the module text size.
Before this change:
$ size fs/btrfs/btrfs.ko
text data bss dec hex filename
1813855 163737 16920
1994512 1e6f10 fs/btrfs/btrfs.ko
After this change:
$ size fs/btrfs/btrfs.ko
text data bss dec hex filename
1813807 163737 16920
1994464 1e6ee0 fs/btrfs/btrfs.ko
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, 13 Mar 2025 16:31:17 +0000 (16:31 +0000)]
btrfs: use memcmp_extent_buffer() at replay_one_extent()
Instead of using memcmp(), which requires copying both file extent items
from each extent buffer into a local buffer, use memcmp_extent_buffer() so
that we only need to copy one of the file extent items and directly use
the extent buffer of the other file extent item for the comparison.
This reduces code size, saves one memory copy and reduces stack usage.
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, 13 Mar 2025 15:47:05 +0000 (15:47 +0000)]
btrfs: update outdated comment for overwrite_item()
The function is exclusively used for log replay since commit
3eb423442483 ("btrfs: remove outdated logic from overwrite_item() and add
assertion"), so update the comment so that it doesn't say it can be used
for logging. Also some minor rewording for clarity and while at it
reformat the affected text so that it fits closer to the 80 characters
limit for comments.
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, 13 Mar 2025 14:25:39 +0000 (14:25 +0000)]
btrfs: use variables to store extent buffer and slot at overwrite_item()
Instead of referring to path->nodes[0] and path->slots[0] multiple times,
which is verbose and confusing since we have an 'eb' and 'slot' variables
as well, introduce local variables 'dst_eb' to point to path->nodes[0] and
'dst_slot' to have path->slots[0], reducing verbosity and making it more
obvious about which extent buffer and slot we are referring to.
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, 13 Mar 2025 14:00:52 +0000 (14:00 +0000)]
btrfs: avoid unnecessary memory allocation and copy at overwrite_item()
There's no need to allocate memory and copy from both the destination and
source extent buffers to compare if the items are equal, we can instead
use memcmp_extent_buffer() which allows to do only one memory allocation
and copy instead of two.
So use memcmp_extent_buffer() instead of memcmp(), allowing us to avoid
one memory allocation, which can fail or be slow while under memory heavy
pressure, avoid the memory copying and reducing code.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Mark Harmstone [Tue, 11 Mar 2025 16:39:25 +0000 (16:39 +0000)]
btrfs: don't clobber ret in btrfs_validate_super()
Commit
2a9bb78cfd36 ("btrfs: validate system chunk array at
btrfs_validate_super()") introduces a call to validate_sys_chunk_array()
in btrfs_validate_super(), which clobbers the value of ret set earlier.
This has the effect of negating the validity checks done earlier, making
it so btrfs could potentially try to mount invalid filesystems.
Fixes:
2a9bb78cfd36 ("btrfs: validate system chunk array at btrfs_validate_super()")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Thu, 20 Feb 2025 09:22:26 +0000 (19:52 +1030)]
btrfs: prepare btrfs_page_mkwrite() for large folios
This changes the assumption that the folio is always page sized.
(Although the ASSERT() for folio order is still kept as-is).
Just replace the PAGE_SIZE with folio_size().
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Thu, 20 Feb 2025 09:22:25 +0000 (19:52 +1030)]
btrfs: prepare extent_io.c for future large folio support
When we're handling folios from filemap, we can no longer assume all
folios are page sized.
Thus for call sites assuming the folio is page sized, change the
PAGE_SIZE usage to folio_size() instead.
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>
Qu Wenruo [Thu, 20 Feb 2025 09:22:24 +0000 (19:52 +1030)]
btrfs: prepare btrfs_launcher_folio() for large folios support
That function is only calling btrfs_qgroup_free_data(), which doesn't
care about the size of the folio.
Just replace the fixed PAGE_SIZE with folio_size().
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>
Qu Wenruo [Mon, 10 Mar 2025 03:20:43 +0000 (13:50 +1030)]
btrfs: replace PAGE_SIZE with folio_size for subpage.[ch]
Since we can no longer assume all data filemap folios are page sized,
use proper folio_size() calls to determine the folio size, as a
preparation for future large data filemap folios.
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>
Qu Wenruo [Mon, 10 Mar 2025 03:16:10 +0000 (13:46 +1030)]
btrfs: add a size parameter to btrfs_alloc_subpage()
Since we can no longer assume page sized folio for data filemap folios,
allow btrfs_alloc_subpage() to accept a new parameter, @fsize,
indicating the folio size.
This doesn't follow the regular behavior of passing a folio directly,
because this function is shared by both data and metadata folios, and
for metadata folios we have extra allocation policy to ensure no large
folios whose sizes are larger than nodesize (unless it's page sized).
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>
Qu Wenruo [Mon, 10 Mar 2025 03:10:47 +0000 (13:40 +1030)]
btrfs: subpage: make btrfs_is_subpage() check against a folio
To support large data folios, we can no longer assume every filemap
folio is page sized.
So btrfs_is_subpage() check must be done against a folio.
Thankfully for metadata folios, we have the full control and ensure a
large folio will not be large than nodesize, so
btrfs_meta_is_subpage() doesn't need this change.
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>
Qu Wenruo [Mon, 10 Mar 2025 05:14:56 +0000 (15:44 +1030)]
btrfs: add extra warning if delayed iput is added when it's not allowed
Since I have triggered the ASSERT() on the delayed iput too many times,
now is the time to add some extra debug warnings for delayed iput.
All delayed iputs should be queued after all ordered extents finish
their IO and all involved workqueues are flushed.
Thus after the btrfs_run_delayed_iputs() inside close_ctree(), there
should be no more delayed puts added.
So introduce a new BTRFS_FS_STATE_NO_DELAYED_IPUT, set after the above
mentioned timing. And all btrfs_add_delayed_iput() will check that flag
and give a WARN_ON_ONCE().
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>
Sun YangKai [Tue, 11 Mar 2025 08:13:14 +0000 (16:13 +0800)]
btrfs: avoid redundant path slot assignment in btrfs_search_forward()
Move path slot assignment before the condition check to prevent
duplicate assignment. Previously, the slot was set both inside and after
the 'slot >= nritems' block with no change in its value, which is
unnecessary.
Signed-off-by: Sun YangKai <sunk67188@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Sun YangKai [Tue, 11 Mar 2025 08:13:13 +0000 (16:13 +0800)]
btrfs: remove unnecessary btrfs_key local variable in btrfs_search_forward()
The 'found_key' variable was only used to temporarily store the found key
before copying it to 'min_key' at the end of the function when returning
success.
Eliminate the 'found_key' variable, and directly store the key into
'min_key' at the exact loop exit points where ret=0 is set, maintaining
identical functionality.
Signed-off-by: Sun YangKai <sunk67188@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Sun YangKai [Tue, 11 Mar 2025 08:13:12 +0000 (16:13 +0800)]
btrfs: simplify the return value handling in search_ioctl()
Move the assignment of -EFAULT to within the error condition check
in fault_in_subpage_writeable(). The previous placement outside the
condition could lead to the error value being overwritten by subsequent
assignments, cause unnecessary assignments.
Simplify loop exit logic by removing redundant goto.
The original code used 'goto err' to bypass post-loop processing after
handling errors from btrfs_search_forward(). However, the loop's
termination naturally falls through to the post-loop section, which
already handles 'ret' values. Replacing 'goto err' with 'break'
eliminates redundant control flow, consolidates error handling, and
makes the loop's exit conditions explicit.
Signed-off-by: Sun YangKai <sunk67188@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Tue, 11 Mar 2025 15:50:50 +0000 (15:50 +0000)]
btrfs: tests: fix chunk map leak after failure to add it to the tree
If we fail to add the chunk map to the fs mapping tree we exit
test_rmap_block() without freeing the chunk map. Fix this by adding a
call to btrfs_free_chunk_map() before exiting the test function if the
call to btrfs_add_chunk_map() failed.
Fixes:
7dc66abb5a47 ("btrfs: use a dedicated data structure for chunk maps")
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Boris Burkov <boris@bur.io>
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, 6 Mar 2025 00:30:24 +0000 (16:30 -0800)]
btrfs: codify pattern for adding block_group to bg_list
Similar to mark_bg_unused() and mark_bg_to_reclaim(), we have a few
places that use bg_list with refcounting, mostly for retrying failures
to reclaim/delete unused.
These have custom logic for handling locking and refcounting the bg_list
properly, but they actually all want to do the same thing, so pull that
logic out into a helper. Unfortunately, mark_bg_unused() does still need
the NEW flag to avoid prematurely marking stuff unused (even if refcount
is fine, we don't want to mess with bg creation), so it cannot use the
new helper.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Boris Burkov [Wed, 5 Mar 2025 23:04:03 +0000 (15:04 -0800)]
btrfs: explicitly ref count block_group on new_bgs list
All other users of the bg_list list_head increment the refcount when
adding to a list and decrement it when deleting from the list. Just for
the sake of uniformity and to try to avoid refcounting bugs, do it for
this list as well.
This does not fix any known ref-counting bug, as the reference belongs
to a single task (trans_handle is not shared and this represents
trans_handle->new_bgs linkage) and will not lose its original refcount
while that thread is running. And BLOCK_GROUP_FLAG_NEW protects against
ref-counting errors "moving" the block group to the unused list without
taking a ref.
With that said, I still believe it is simpler to just hold the extra ref
count for this list user as well.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Boris Burkov [Mon, 3 Mar 2025 23:01:05 +0000 (15:01 -0800)]
btrfs: make btrfs_discard_workfn() block_group ref explicit
Currently, the async discard machinery owns a ref to the block_group
when the block_group is queued on a discard list. However, to handle
races with discard cancellation and the discard workfn, we have a
specific logic to detect that the block_group is *currently* running in
the workfn, to protect the workfn's usage amidst cancellation.
As far as I can tell, this doesn't have any overt bugs (though
finish_discard_pass() and remove_from_discard_list() racing can have a
surprising outcome for the caller of remove_from_discard_list() in that
it is again added at the end).
But it is needlessly complicated to rely on locking and the nullity of
discard_ctl->block_group. Simplify this significantly by just taking a
refcount while we are in the workfn and unconditionally drop it in both
the remove and workfn paths, regardless of if they race.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Boris Burkov [Wed, 5 Mar 2025 23:16:57 +0000 (15:16 -0800)]
btrfs: harden block_group::bg_list against list_del() races
As far as I can tell, these calls of list_del_init() on bg_list cannot
run concurrently with btrfs_mark_bg_unused() or btrfs_mark_bg_to_reclaim(),
as they are in transaction error paths and situations where the block
group is readonly.
However, if there is any chance at all of racing with mark_bg_unused(),
or a different future user of bg_list, better to be safe than sorry.
Otherwise we risk the following interleaving (bg_list refcount in parens)
T1 (some random op) T2 (btrfs_mark_bg_unused)
!list_empty(&bg->bg_list); (1)
list_del_init(&bg->bg_list); (1)
list_move_tail (1)
btrfs_put_block_group (0)
btrfs_delete_unused_bgs
bg = list_first_entry
list_del_init(&bg->bg_list);
btrfs_put_block_group(bg); (-1)
Ultimately, this results in a broken ref count that hits zero one deref
early and the real final deref underflows the refcount, resulting in a WARNING.
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>
Boris Burkov [Wed, 5 Mar 2025 23:03:13 +0000 (15:03 -0800)]
btrfs: fix block group refcount race in btrfs_create_pending_block_groups()
Block group creation is done in two phases, which results in a slightly
unintuitive property: a block group can be allocated/deallocated from
after btrfs_make_block_group() adds it to the space_info with
btrfs_add_bg_to_space_info(), but before creation is completely completed
in btrfs_create_pending_block_groups(). As a result, it is possible for a
block group to go unused and have 'btrfs_mark_bg_unused' called on it
concurrently with 'btrfs_create_pending_block_groups'. This causes a
number of issues, which were fixed with the block group flag
'BLOCK_GROUP_FLAG_NEW'.
However, this fix is not quite complete. Since it does not use the
unused_bg_lock, it is possible for the following race to occur:
btrfs_create_pending_block_groups btrfs_mark_bg_unused
if list_empty // false
list_del_init
clear_bit
else if (test_bit) // true
list_move_tail
And we get into the exact same broken ref count and invalid new_bgs
state for transaction cleanup that BLOCK_GROUP_FLAG_NEW was designed to
prevent.
The broken refcount aspect will result in a warning like:
[1272.943527] refcount_t: underflow; use-after-free.
[1272.943967] WARNING: CPU: 1 PID: 61 at lib/refcount.c:28 refcount_warn_saturate+0xba/0x110
[1272.944731] Modules linked in: btrfs virtio_net xor zstd_compress raid6_pq null_blk [last unloaded: btrfs]
[1272.945550] CPU: 1 UID: 0 PID: 61 Comm: kworker/u32:1 Kdump: loaded Tainted: G W 6.14.0-rc5+ #108
[1272.946368] Tainted: [W]=WARN
[1272.946585] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
[1272.947273] Workqueue: btrfs_discard btrfs_discard_workfn [btrfs]
[1272.947788] RIP: 0010:refcount_warn_saturate+0xba/0x110
[1272.949532] RSP: 0018:
ffffbf1200247df0 EFLAGS:
00010282
[1272.949901] RAX:
0000000000000000 RBX:
ffffa14b00e3f800 RCX:
0000000000000000
[1272.950437] RDX:
0000000000000000 RSI:
ffffbf1200247c78 RDI:
00000000ffffdfff
[1272.950986] RBP:
ffffa14b00dc2860 R08:
00000000ffffdfff R09:
ffffffff90526268
[1272.951512] R10:
ffffffff904762c0 R11:
0000000063666572 R12:
ffffa14b00dc28c0
[1272.952024] R13:
0000000000000000 R14:
ffffa14b00dc2868 R15:
000001285dcd12c0
[1272.952850] FS:
0000000000000000(0000) GS:
ffffa14d33c40000(0000) knlGS:
0000000000000000
[1272.953458] CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
[1272.953931] CR2:
00007f838cbda000 CR3:
000000010104e000 CR4:
00000000000006f0
[1272.954474] Call Trace:
[1272.954655] <TASK>
[1272.954812] ? refcount_warn_saturate+0xba/0x110
[1272.955173] ? __warn.cold+0x93/0xd7
[1272.955487] ? refcount_warn_saturate+0xba/0x110
[1272.955816] ? report_bug+0xe7/0x120
[1272.956103] ? handle_bug+0x53/0x90
[1272.956424] ? exc_invalid_op+0x13/0x60
[1272.956700] ? asm_exc_invalid_op+0x16/0x20
[1272.957011] ? refcount_warn_saturate+0xba/0x110
[1272.957399] btrfs_discard_cancel_work.cold+0x26/0x2b [btrfs]
[1272.957853] btrfs_put_block_group.cold+0x5d/0x8e [btrfs]
[1272.958289] btrfs_discard_workfn+0x194/0x380 [btrfs]
[1272.958729] process_one_work+0x130/0x290
[1272.959026] worker_thread+0x2ea/0x420
[1272.959335] ? __pfx_worker_thread+0x10/0x10
[1272.959644] kthread+0xd7/0x1c0
[1272.959872] ? __pfx_kthread+0x10/0x10
[1272.960172] ret_from_fork+0x30/0x50
[1272.960474] ? __pfx_kthread+0x10/0x10
[1272.960745] ret_from_fork_asm+0x1a/0x30
[1272.961035] </TASK>
[1272.961238] ---[ end trace
0000000000000000 ]---
Though we have seen them in the async discard workfn as well. It is
most likely to happen after a relocation finishes which cancels discard,
tears down the block group, etc.
Fix this fully by taking the lock around the list_del_init + clear_bit
so that the two are done atomically.
Fixes:
0657b20c5a76 ("btrfs: fix use-after-free of new block group that became unused")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Fri, 7 Mar 2025 12:52:30 +0000 (12:52 +0000)]
btrfs: remove unnecessary fs_info argument from btrfs_add_block_group_cache()
The fs_info can be taken from the given block group, so there is no need
to pass it as an argument. Also rename the local variable from 'info' to
'fs_info' which is more widely used, more clear and to be more consistent.
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, 7 Mar 2025 12:45:04 +0000 (12:45 +0000)]
btrfs: remove unnecessary fs_info argument from delete_block_group_cache()
The fs_info can be taken from the given block group, so there is no need
to pass it as an argument.
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, 7 Mar 2025 12:33:50 +0000 (12:33 +0000)]
btrfs: remove unnecessary fs_info argument from create_reloc_inode()
The fs_info can be taken from the given block group, so there is no need
to pass it as an argument.
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, 7 Mar 2025 12:27:15 +0000 (12:27 +0000)]
btrfs: make btrfs_iget_path() return a btrfs inode instead
It's an internal function and btrfs_iget() is now returning a btrfs inode,
so change btrfs_iget_path() to also return a btrfs inode instead of a VFS
inode.
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, 7 Mar 2025 12:16:10 +0000 (12:16 +0000)]
btrfs: make btrfs_iget() return a btrfs inode instead
It's an internal function and most of the time the callers are doing a lot
of BTRFS_I() calls on the returned VFS inode to get the btrfs inode, so
change the return type to struct btrfs_inode instead.
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, 6 Mar 2025 17:17:22 +0000 (17:17 +0000)]
btrfs: pass a btrfs_inode to fixup_inode_link_count()
fixup_inode_link_count() mostly wants to use a btrfs_inode, plus it's an
internal function so it should take btrfs_inode instead of a VFS inode.
Change the argument type to btrfs_inode, avoiding several BTRFS_I() calls
too.
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, 6 Mar 2025 17:11:00 +0000 (17:11 +0000)]
btrfs: return a btrfs_inode from read_one_inode()
All callers of read_one_inode() are mostly interested in the btrfs_inode
structure rather than the VFS inode, so make read_one_inode() return
the btrfs_inode instead, avoiding lots of BTRFS_I() calls.
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, 6 Mar 2025 16:42:28 +0000 (16:42 +0000)]
btrfs: return a btrfs_inode from btrfs_iget_logging()
All callers of btrfs_iget_logging() are interested in the btrfs_inode
structure rather than the VFS inode, so make btrfs_iget_logging() return
the btrfs_inode instead, avoiding lots of BTRFS_I() calls.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Mark Harmstone [Thu, 6 Mar 2025 10:58:46 +0000 (10:58 +0000)]
btrfs: avoid linker error in btrfs_find_create_tree_block()
The inline function btrfs_is_testing() is hardcoded to return 0 if
CONFIG_BTRFS_FS_RUN_SANITY_TESTS is not set. Currently we're relying on
the compiler optimizing out the call to alloc_test_extent_buffer() in
btrfs_find_create_tree_block(), as it's not been defined (it's behind an
#ifdef).
Add a stub version of alloc_test_extent_buffer() to avoid linker errors
on non-standard optimization levels. This problem was seen on GCC 14
with -O0 and is helps to see symbols that would be otherwise optimized
out.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Fri, 7 Mar 2025 04:06:10 +0000 (14:36 +1030)]
btrfs: run btrfs_error_commit_super() early
[BUG]
Even after all the error fixes related the
"ASSERT(list_empty(&fs_info->delayed_iputs));" in close_ctree(), I can
still hit it reliably with my experimental 2K block size.
[CAUSE]
In my case, all the error is triggered after the fs is already in error
status.
I find the following call trace to be the cause of race:
Main thread | endio_write_workers
---------------------------------------------+---------------------------
close_ctree() |
|- btrfs_error_commit_super() |
| |- btrfs_cleanup_transaction() |
| | |- btrfs_destroy_all_ordered_extents() |
| | |- btrfs_wait_ordered_roots() |
| |- btrfs_run_delayed_iputs() |
| | btrfs_finish_ordered_io()
| | |- btrfs_put_ordered_extent()
| | |- btrfs_add_delayed_iput()
|- ASSERT(list_empty(delayed_iputs)) |
!!! Triggered !!!
The root cause is that, btrfs_wait_ordered_roots() only wait for
ordered extents to finish their IOs, not to wait for them to finish and
removed.
[FIX]
Since btrfs_error_commit_super() will flush and wait for all ordered
extents, it should be executed early, before we start flushing the
workqueues.
And since btrfs_error_commit_super() now runs early, there is no need to
run btrfs_run_delayed_iputs() inside it, so just remove the
btrfs_run_delayed_iputs() call from btrfs_error_commit_super().
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Daniel Vacek [Thu, 6 Mar 2025 13:15:35 +0000 (14:15 +0100)]
btrfs: defrag: extend ioctl to accept compression levels
The zstd and zlib compression types support setting compression levels.
Enhance the defrag interface to specify the levels as well. For zstd the
negative (realtime) levels are also accepted.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Daniel Vacek <neelx@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Thu, 6 Mar 2025 17:47:34 +0000 (17:47 +0000)]
btrfs: send: simplify return logic from send_encoded_extent()
The 'out' label is pointless as we don't have anything to cleanup anymore
(we used to have an inode to iput), so remove it and make error paths
directly return an error.
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 [Thu, 6 Mar 2025 17:45:40 +0000 (17:45 +0000)]
btrfs: send: remove unnecessary inode lookup at send_encoded_inline_extent()
We are doing a lookup of the inode but we don't use it at all. So just
remove this pointless lookup.
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 [Thu, 6 Mar 2025 16:07:18 +0000 (16:07 +0000)]
btrfs: avoid unnecessary bio dereference at run_one_async_done()
We have dereferenced the async_submit_bio structure and extracted the bio
pointer into a local variable, so there's no need to dereference it again
when calling btrfs_bio_end_io(). Just use "bio->bi_status" instead of the
longer expression "async->bbio->bio.bi_status".
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 [Thu, 6 Mar 2025 14:25:38 +0000 (14:25 +0000)]
btrfs: fix non-empty delayed iputs list on unmount due to async workers
At close_ctree() after we have ran delayed iputs either explicitly through
calling btrfs_run_delayed_iputs() or later during the call to
btrfs_commit_super() or btrfs_error_commit_super(), we assert that the
delayed iputs list is empty.
We have (another) race where this assertion might fail because we have
queued an async write into the fs_info->workers workqueue. Here's how it
happens:
1) We are submitting a data bio for an inode that is not the data
relocation inode, so we call btrfs_wq_submit_bio();
2) btrfs_wq_submit_bio() submits a work for the fs_info->workers queue
that will run run_one_async_done();
3) We enter close_ctree(), flush several work queues except
fs_info->workers, explicitly run delayed iputs with a call to
btrfs_run_delayed_iputs() and then again shortly after by calling
btrfs_commit_super() or btrfs_error_commit_super(), which also run
delayed iputs;
4) run_one_async_done() is executed in the work queue, and because there
was an IO error (bio->bi_status is not 0) it calls btrfs_bio_end_io(),
which drops the final reference on the associated ordered extent by
calling btrfs_put_ordered_extent() - and that adds a delayed iput for
the inode;
5) At close_ctree() we find that after stopping the cleaner and
transaction kthreads the delayed iputs list is not empty, failing the
following assertion:
ASSERT(list_empty(&fs_info->delayed_iputs));
Fix this by flushing the fs_info->workers workqueue before running delayed
iputs at close_ctree().
David reported this when running generic/648, which exercises IO error
paths by using the DM error table.
Reported-by: David Sterba <dsterba@suse.com>
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 [Wed, 5 Mar 2025 03:21:39 +0000 (13:51 +1030)]
btrfs: reject out-of-band dirty folios during writeback
[OUT-OF-BAND DIRTY FOLIOS]
An out-of-band folio means the folio is marked dirty but without
notifying the filesystem.
This can lead to various problems, not limited to:
- No folio::private to track per block status
- No proper space reserved for such a dirty folio
[HISTORY IN BTRFS]
This used to be a problem related to get_user_page(), but with the
introduction of pin_user_pages*(), we should no longer hit such
case anymore.
In btrfs, we have a long history of catching such out-of-band dirty
folios by:
- Mark the folio ordered during delayed allocation
- Check the folio ordered flag during writeback
If the folio has no ordered flag, it means it doesn't go through
delayed allocation, thus it's definitely an out-of-band
one.
If we got one, we go through COW fixup, which will re-dirty the folio
with proper handling in another workqueue.
[PROBLEMS OF COW-FIXUP]
Such workaround is a blockage for us to migrate to iomap (it requires
extra flags to trace if a folio is dirtied by the fs or not) and I'd
argue it's not data checksum safe, since if a folio can be marked dirty
without informing the fs, the content can also change at any time.
But with the introduction of pin_user_pages*() during v5.8 merge
window, such out-of-band dirty folio such be treated as a bug.
Ext4 has treated such case by warning and erroring out even before
pin_user_pages*().
Furthermore, there are already proofs that such folio ordered flag
tracking can be screwed up by incorrect error handling, check the commit
messages of the following commits:
06f364284794 ("btrfs: do proper folio cleanup when cow_file_range() failed")
c2b47df81c8e ("btrfs: do proper folio cleanup when run_delalloc_nocow() failed")
[FIXES]
Unlike btrfs, ext4 and xfs (iomap) never bother handling such
out-of-band dirty folios.
- Ext4 just warns and errors out
- Iomap always follows the folio/block dirty flags
And there is nothing really COW specific, xfs also supports COW too.
Here we take one step towards ext4 by doing warning and erroring out.
But since the cow fixup thing is introduced from the beginning, we keep
the old behavior for non-experimental builds, and only do the new warning
for experimental builds before we're 100% sure and remove cow fixup.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Dan Carpenter [Wed, 5 Mar 2025 15:01:57 +0000 (18:01 +0300)]
btrfs: return a literal instead of a variable in btrfs_init_dev_replace()
This is just a small clean up, it doesn't change how the code works.
Originally this code had a goto so we needed to set "ret = 0;" but now
it returns directly and so we can simplify it a bit by doing a
"return 0;" and removing the assignment.
Reviewed-by: Anand Jain <anand.jain@oracle.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>
Filipe Manana [Wed, 5 Mar 2025 13:16:08 +0000 (13:16 +0000)]
btrfs: move btrfs_cleanup_bio() code into its single caller
The btrfs_cleanup_bio() helper is trivial and has a single caller, there's
no point in having a dedicated helper function. So get rid of it and move
its code into the caller (btrfs_bio_end_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>
Filipe Manana [Wed, 5 Mar 2025 12:22:39 +0000 (12:22 +0000)]
btrfs: move __btrfs_bio_end_io() code into its single caller
The __btrfs_bio_end_io() helper is trivial and has a single caller, so
there's no point in having a dedicated helper function. Further the double
underscore prefix in the name is discouraged. So get rid of it and move
its code into the caller (btrfs_bio_end_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>
Filipe Manana [Wed, 5 Mar 2025 16:52:26 +0000 (16:52 +0000)]
btrfs: fix non-empty delayed iputs list on unmount due to compressed write workers
At close_ctree() after we have ran delayed iputs either through explicitly
calling btrfs_run_delayed_iputs() or later during the call to
btrfs_commit_super() or btrfs_error_commit_super(), we assert that the
delayed iputs list is empty.
When we have compressed writes this assertion may fail because delayed
iputs may have been added to the list after we last ran delayed iputs.
This happens like this:
1) We have a compressed write bio executing;
2) We enter close_ctree() and flush the fs_info->endio_write_workers
queue which is the queue used for running ordered extent completion;
3) The compressed write bio finishes and enters
btrfs_finish_compressed_write_work(), where it calls
btrfs_finish_ordered_extent() which in turn calls
btrfs_queue_ordered_fn(), which queues a work item in the
fs_info->endio_write_workers queue that we have flushed before;
4) At close_ctree() we proceed, run all existing delayed iputs and
call btrfs_commit_super() (which also runs delayed iputs), but before
we run the following assertion below:
ASSERT(list_empty(&fs_info->delayed_iputs))
A delayed iput is added by the step below...
5) The ordered extent completion job queued in step 3 runs and results in
creating a delayed iput when dropping the last reference of the ordered
extent (a call to btrfs_put_ordered_extent() made from
btrfs_finish_one_ordered());
6) At this point the delayed iputs list is not empty, so the assertion at
close_ctree() fails.
Fix this by flushing the fs_info->compressed_write_workers queue at
close_ctree() before flushing the fs_info->endio_write_workers queue,
respecting the queue dependency as the later is responsible for the
execution of ordered extent completion.
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 3 Mar 2025 14:55:41 +0000 (15:55 +0100)]
btrfs: unify inode variable naming
Rename binode to inode in local variables or parameters so it's more
unified with the rest of the code.
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 3 Mar 2025 14:55:34 +0000 (15:55 +0100)]
btrfs: pass struct to btrfs_ioctl_subvol_getflags()
Pass a struct btrfs_inode to btrfs_ioctl_subvol_getflags() as it's an
internal interface, allowing to remove some use of BTRFS_I.
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 3 Mar 2025 14:55:32 +0000 (15:55 +0100)]
btrfs: simplify local variables in btrfs_ioctl_resize()
Remove some redundant variables and assignments, move variable
declarations to their closest scope.
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 3 Mar 2025 14:55:26 +0000 (15:55 +0100)]
btrfs: pass struct btrfs_inode to btrfs_sync_inode_flags_to_i_flags()
Pass a struct btrfs_inode to btrfs_sync_inode_flags_to_i_flags() as it's
an internal interface.
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 3 Mar 2025 14:55:23 +0000 (15:55 +0100)]
btrfs: pass root pointers to search tree ioctl helpers
The search tree ioctl use btrfs_root so change that from btrfs_inode
pointers so we don't have to do the conversion.
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 3 Mar 2025 14:55:17 +0000 (15:55 +0100)]
btrfs: pass btrfs_root pointers to send ioctl parameters
The ioctl switch btrfs_ioctl() provides several parameter types for
convenience so we don't have to do the conversion in the callbacks.
Pass root pointers to the send related functions.
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 3 Mar 2025 14:55:15 +0000 (15:55 +0100)]
btrfs: parameter constification in ioctl.c
Add const to function parameters that are not changed.
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Tue, 25 Feb 2025 02:33:03 +0000 (13:03 +1030)]
btrfs: allow debug builds to accept 2K block size
Currently we only support two block sizes, 4K and PAGE_SIZE.
This means on the most common architecture x86_64, we have no way to
test subpage block size. And that's exactly I have an aarch64 machine
dedicated for subpage tests.
But this is still a hurdle for a lot of btrfs developers, and to improve
the test coverage mostly on x86_64, here we enable debug builds to
accept 2K block size.
This involves:
- Introduce a dedicated minimal block size macro
BTRFS_MIN_BLOCKSIZE, which depends on if CONFIG_BTRFS_DEBUG is set.
If so it's 2K, otherwise it's 4K as usual.
- Allow 4K, PAGE_SIZE and BTRFS_MIN_BLOCKSIZE as block size
- Update subpage block size checks to be based on BTRFS_MIN_BLOCKSIZE
- Export the new supported blocksize through sysfs interfaces
As most of the subpage support is already pretty mature, there is no
extra work needed to support the extra 2K block size.
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, 25 Feb 2025 04:00:44 +0000 (14:30 +1030)]
btrfs: properly limit inline data extent according to block size
Btrfs utilizes inline data extent for the following cases:
- Regular small files
- Symlinks
And "btrfs check" detects any file extents that are too large as an
error.
It's not a problem for 4K block size, but for the incoming smaller
block sizes (2K), it can cause problems due to bad limits:
- Non-compressed inline data extents
We do not allow a non-compressed inline data extent to be as large as
block size.
- Symlinks
Currently the only real limit on symlinks are 4K, which can be larger
than 2K block size.
These will result btrfs-check to report too large file extents.
Fix it by adding proper size checks for the above cases.
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 [Sat, 15 Feb 2025 05:58:06 +0000 (16:28 +1030)]
btrfs: remove the subpage related warning message
Since the initial enablement of block size < page size support for
btrfs in v5.15, we have hit several milestones for block size < page
size (subpage) support:
- RAID56 subpage support
In v5.19
- Refactored scrub support to support subpage better
In v6.4
- Block perfect (previously requires page aligned ranges) compressed write
In v6.13
- Various error handling fixes involving subpage
In v6.14
Finally the only missing feature is the pretty simple and harmless
inlined data extent creation, just added in previous patches.
Now btrfs has all of its features ready for both regular and subpage
cases, there is no reason to output a warning about the experimental
subpage support, and we can finally remove it now.
Acked-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 [Fri, 15 Nov 2024 06:03:44 +0000 (16:33 +1030)]
btrfs: allow inline data extents creation if block size < page size
Previously inline data extents creation was disabled if the block size
(previously called sector size) is smaller than the page size, for the
following reasons:
- Possible mixed inline and regular data extents
However this is also the same if the block size matches the page size,
thus we do not treat mixed inline and regular extents as an error.
And the chance to cause mixed inline and regular data extents are not
even increased, it has the same requirement (compressed inline data
extent covering the whole first block, followed by regular extents).
- Inability to handle async/inline delalloc range for block size < page
size cases
This is already fixed since commit
1d2fbb7f1f9e ("btrfs: allow
compression even if the range is not page aligned").
This was the major technical obstacle, but it's not anymore.
With that removed, we can enable inline data extents creation no matter
the block size nor the page size, allowing btrfs to have the same
capacity for all block sizes.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Wed, 30 Oct 2024 06:34:02 +0000 (17:04 +1030)]
btrfs: allow buffered write to avoid full page read if it's block aligned
[BUG]
Since the support of block size (sector size) < page size for btrfs,
test case generic/563 fails with 4K block size and 64K page size:
--- tests/generic/563.out 2024-04-25 18:13:45.
178550333 +0930
+++ /home/adam/xfstests-dev/results//generic/563.out.bad 2024-09-30 09:09:16.
155312379 +0930
@@ -3,7 +3,8 @@
read is in range
write is in range
write -> read/write
-read is in range
+read has value of
8388608
+read is NOT in range -33792 .. 33792
write is in range
...
[CAUSE]
The test case creates a 8MiB file, then does buffered write into the 8MiB
using 4K block size, to overwrite the whole file.
On 4K page sized systems, since the write range covers the full block and
page, btrfs will not bother reading the page, just like what XFS and EXT4
do.
But on 64K page sized systems, although the 4K sized write is still block
aligned, it's not page aligned anymore, thus btrfs will read the full
page, which will be accounted by cgroup and fail the test.
As the test case itself expects such 4K block aligned write should not
trigger any read.
Such expected behavior is an optimization to reduce folio reads when
possible, and unfortunately btrfs does not implement such optimization.
[FIX]
To skip the full page read, we need to do the following modification:
- Do not trigger full page read as long as the buffered write is block
aligned
This is pretty simple by modifying the check inside
prepare_uptodate_page().
- Skip already uptodate blocks during full page read
Or we can lead to the following data corruption:
0 32K 64K
|///////| |
Where the file range [0, 32K) is dirtied by buffered write, the
remaining range [32K, 64K) is not.
When reading the full page, since [0,32K) is only dirtied but not
written back, there is no data extent map for it, but a hole covering
[0, 64k).
If we continue reading the full page range [0, 64K), the dirtied range
will be filled with 0 (since there is only a hole covering the whole
range).
This causes the dirtied range to get lost.
With this optimization, btrfs can pass generic/563 even if the page size
is larger than fs block size.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Wed, 30 Oct 2024 06:34:00 +0000 (17:04 +1030)]
btrfs: make btrfs_do_readpage() to do block-by-block read
Currently if btrfs has its block size (the older sector size) smaller
than the page size, btrfs_do_readpage() will handle the range extent by
extent, this is good for performance as it doesn't need to re-lookup the
same extent map again and again.
(Although get_extent_map() already does extra cached em check, thus
the optimization is not that obvious.)
This is totally fine and is a valid optimization, but it has an
assumption that there is no partial uptodate range in the page.
Meanwhile there is an incoming feature, requiring btrfs to skip the full
page read if a buffered write range covers a full block but not a full
page.
In that case, we can have a page that is partially uptodate, and the
current per-extent lookup cannot handle such case.
So here we change btrfs_do_readpage() to do block-by-block read, this
simplifies the following things:
- Remove the need for @iosize variable
Because we just use sectorsize as our increment.
- Remove @pg_offset, and calculate it inside the loop when needed
It's just offset_in_folio().
- Use a for() loop instead of a while() loop
This will slightly reduce the read performance for subpage cases, but for
the future where we need to skip already uptodate blocks, it should still
be worth.
For block size == page size, this brings no performance change.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Mon, 10 Feb 2025 08:22:33 +0000 (18:52 +1030)]
btrfs: introduce a read path dedicated extent lock helper
Currently we're using btrfs_lock_and_flush_ordered_range() for both
btrfs_read_folio() and btrfs_readahead(), but it has one critical
problem for future subpage optimizations:
- It will call btrfs_start_ordered_extent() to writeback the involved
folios
But remember we're calling btrfs_lock_and_flush_ordered_range() at
read paths, meaning the folio is already locked by read path.
If we really trigger writeback for those already locked folios, this
will lead to a deadlock and writeback cannot get the folio lock.
Such dead lock is prevented by the fact that btrfs always keeps a
dirty folio also uptodate, by either dirtying all blocks of the folio,
or by reading the whole folio before dirtying.
To prepare for the incoming patch which allows btrfs to skip full folio
read if the buffered write is block aligned, we have to start by solving
the possible deadlock first.
Instead of blindly calling btrfs_start_ordered_extent(), introduce a
new helper, which is smarter in the following ways:
- Only wait and flush the ordered extent if
* The folio doesn't even have private bit set
* Part of the blocks of the ordered extent are not uptodate
This can happen by:
* The folio writeback finished, then got invalidated.
There are a lot of reasons that a folio can get invalidated,
from memory pressure to direct IO (which invalidates all folios
of the range).
But OE not yet finished.
We have to wait for the ordered extent, as the OE may contain
to-be-inserted data checksum.
Without waiting, our read can fail due to the missing checksum.
But either way, the OE should not need any extra flush inside the
locked folio range.
- Skip the ordered extent completely if
* All the blocks are dirty
This happens when OE creation is caused by a folio writeback whose
file offset is before our folio.
E.g. 16K page size and 4K block size
0 8K 16K 24K 32K
|//////////////||///////| |
The writeback of folio 0 created an OE for range [0, 24K), but since
folio 16K is not fully uptodate, a read is triggered for folio 16K.
The writeback will never happen (we're holding the folio lock for
read), nor will the OE finish.
Thus we must skip the range.
* All the blocks are uptodate
This happens when the writeback finished, but OE not yet finished.
Since the blocks are already uptodate, we can skip the OE range.
The new helper lock_extents_for_read() will do a loop for the target
range by:
1) Lock the full range
2) If there is no ordered extent in the remaining range, exit
3) If there is an ordered extent that we can skip
Skip to the end of the OE, and continue checking
We do not trigger writeback nor wait for the OE.
4) If there is an ordered extent that we cannot skip
Unlock the whole extent range and start the ordered extent.
And also update btrfs_start_ordered_extent() to add two more parameters:
@nowriteback_start and @nowriteback_len, to prevent triggering flush for
a certain range.
This will allow us to handle the following case properly in the future:
16K page size, 4K btrfs block size:
0 4K 8K 12K 16K 20K 24K 28K 32K
|/////////////////////////////||////////////////| | |
|<-------------------- OE 2 ------------------->| |< OE 1 >|
The folio has been written back before, thus we have an OE at
[28K, 32K).
Although the OE 1 finished its IO, the OE is not yet removed from IO
tree.
The folio got invalidated after writeback completed and before the
ordered extent finished.
And [16K, 24K) range is dirty and uptodate, caused by a block aligned
buffered write (and future enhancements allowing btrfs to skip full
folio read for such case).
But writeback for folio 0 has began, thus it generated OE 2, covering
range [0, 24K).
Since the full folio 16K is not uptodate, if we want to read the folio,
the existing btrfs_lock_and_flush_ordered_range() will dead lock, by:
btrfs_read_folio()
| Folio 16K is already locked
|- btrfs_lock_and_flush_ordered_range()
|- btrfs_start_ordered_extent() for range [16K, 24K)
|- filemap_fdatawrite_range() for range [16K, 24K)
|- extent_write_cache_pages()
folio_lock() on folio 16K, deadlock.
But now we will have the following sequence:
btrfs_read_folio()
| Folio 16K is already locked
|- lock_extents_for_read()
|- can_skip_ordered_extent() for range [16K, 24K)
| Returned true, the range [16K, 24K) will be skipped.
|- can_skip_ordered_extent() for range [28K, 32K)
| Returned false.
|- btrfs_start_ordered_extent() for range [28K, 32K) with
[16K, 32K) as no writeback range
No writeback for folio 16K will be triggered.
And there will be no more possible deadlock on the same folio.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo [Fri, 15 Nov 2024 06:03:43 +0000 (16:33 +1030)]
btrfs: fix the qgroup data free range for inline data extents
Inside function __cow_file_range_inline() since the inlined data no
longer take any data space, we need to free up the reserved space.
However the code is still using the old page size == sector size
assumption, and will not handle subpage case well.
Thankfully it is not going to cause any problems because we have two extra
safe nets:
- Inline data extents creation is disabled for sector size < page size
cases for now
But it won't stay that for long.
- btrfs_qgroup_free_data() will only clear ranges which have been already
reserved
So even if we pass a range larger than what we need, it should still
be fine, especially there is only reserved space for a single block at
file offset 0 of an inline data extent.
But just for the sake of consistency, fix the call site to use
sectorsize instead of page size.
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 [Fri, 15 Nov 2024 08:45:34 +0000 (19:15 +1030)]
btrfs: prevent inline data extents read from touching blocks beyond its range
Currently reading an inline data extent will zero out the remaining
range in the page.
This is not yet causing problems even for block size < page size
(subpage) cases because:
1) An inline data extent always starts at file offset 0
Meaning at page read, we always read the inline extent first, before
any other blocks in the page. Then later blocks are properly read out
and re-fill the zeroed out ranges.
2) Currently btrfs will read out the whole page if a buffered write is
not page aligned
So a page is either fully uptodate at buffered write time (covers the
whole page), or we will read out the whole page first.
Meaning there is nothing to lose for such an inline extent read.
But it's still not ideal:
- We're zeroing out the page twice
Once done by read_inline_extent()/uncompress_inline(), once done by
btrfs_do_readpage() for ranges beyond i_size.
- We're touching blocks that don't belong to the inline extent
In the incoming patches, we can have a partial uptodate folio, of
which some dirty blocks can exist while the page is not fully uptodate:
The page size is 16K and block size is 4K:
0 4K 8K 12K 16K
| | |/////////| |
And range [8K, 12K) is dirtied by a buffered write, the remaining
blocks are not uptodate.
If range [0, 4K) contains an inline data extent, and we try to read
the whole page, the current behavior will overwrite range [8K, 12K)
with zero and cause data loss.
So to make the behavior more consistent and in preparation for future
changes, limit the inline data extents read to only zero out the range
inside the first block, not the whole page.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Anand Jain [Wed, 29 Jan 2025 15:21:46 +0000 (23:21 +0800)]
btrfs: sysfs: accept size suffixes for read policy values
We now parse human-friendly size values (e.g. '1G', '2M') when setting
read policies.
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 [Mon, 24 Feb 2025 08:15:17 +0000 (09:15 +0100)]
btrfs: use BTRFS_PATH_AUTO_FREE in load_free_space_tree()
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with simple goto -> return conversions.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 24 Feb 2025 08:15:17 +0000 (09:15 +0100)]
btrfs: use BTRFS_PATH_AUTO_FREE in clear_free_space_tree()
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with simple goto -> return conversions.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 24 Feb 2025 08:15:17 +0000 (09:15 +0100)]
btrfs: use BTRFS_PATH_AUTO_FREE in populate_free_space_tree()
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with simple goto -> return conversions.
This applies to both path and path2.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 24 Feb 2025 08:15:17 +0000 (09:15 +0100)]
btrfs: use BTRFS_PATH_AUTO_FREE in btrfs_remove_free_space_inode()
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with simple goto -> return conversions.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 24 Feb 2025 08:15:17 +0000 (09:15 +0100)]
btrfs: use BTRFS_PATH_AUTO_FREE in btrfs_lookup_bio_sums()
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 24 Feb 2025 08:15:17 +0000 (09:15 +0100)]
btrfs: use BTRFS_PATH_AUTO_FREE in run_delayed_extent_op()
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with simple goto -> return conversions.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 24 Feb 2025 08:15:17 +0000 (09:15 +0100)]
btrfs: use BTRFS_PATH_AUTO_FREE in btrfs_lookup_extent_info()
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with simple goto -> return conversions.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 24 Feb 2025 08:15:17 +0000 (09:15 +0100)]
btrfs: use BTRFS_PATH_AUTO_FREE in btrfs_get_name()
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with some return simplifications.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 24 Feb 2025 08:15:17 +0000 (09:15 +0100)]
btrfs: use BTRFS_PATH_AUTO_FREE in btrfs_init_root_free_objectid()
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with simple goto -> return conversions.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 24 Feb 2025 08:15:17 +0000 (09:15 +0100)]
btrfs: use BTRFS_PATH_AUTO_FREE in load_global_roots()
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with simple goto -> return conversions.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 24 Feb 2025 08:15:17 +0000 (09:15 +0100)]
btrfs: use BTRFS_PATH_AUTO_FREE in btrfs_check_dir_item_collision()
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with simple goto -> return conversions.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 24 Feb 2025 08:15:17 +0000 (09:15 +0100)]
btrfs: use BTRFS_PATH_AUTO_FREE in btrfs_run_dev_replace()
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with simple goto -> return conversions.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 24 Feb 2025 08:15:17 +0000 (09:15 +0100)]
btrfs: use BTRFS_PATH_AUTO_FREE in btrfs_init_dev_replace()
This is the trivial pattern for path auto free, initialize at the
beginning and free at the end with simple goto -> return conversions.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Mon, 24 Feb 2025 08:13:57 +0000 (09:13 +0100)]
btrfs: do trivial BTRFS_PATH_AUTO_FREE conversions
The most trivial pattern for the auto freeing when the variable is
declared with the macro and the final btrfs_free_path() is removed.
There are almost none goto -> return conversions and there's no other
function cleanup.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Tue, 25 Feb 2025 17:24:46 +0000 (18:24 +0100)]
btrfs: use num_extent_folios() in for loop bounds
As the helper num_extent_folios() is now __pure, we can use it in for
loop without storing its value in a variable explicitly, the compiler
will do this for us.
The effects on btrfs.ko is -200 bytes and there are stack space savings
too:
btrfs_clone_extent_buffer -8 (32 -> 24)
btrfs_clear_buffer_dirty -8 (48 -> 40)
clear_extent_buffer_uptodate -8 (40 -> 32)
set_extent_buffer_dirty -8 (32 -> 24)
write_one_eb -8 (88 -> 80)
set_extent_buffer_uptodate -8 (40 -> 32)
read_extent_buffer_pages_nowait -16 (64 -> 48)
find_extent_buffer -8 (32 -> 24)
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Tue, 25 Feb 2025 17:24:43 +0000 (18:24 +0100)]
btrfs: add __pure attribute to eb page and folio counters
The functions qualify for the pure attribute as they always return the
same value for the same argument (in the given scope). This allows to
optimize the calls and cache the value.
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Tue, 25 Feb 2025 16:16:48 +0000 (17:16 +0100)]
btrfs: simplify parameters of metadata folio helpers
Unlike folio helpers for date the ones for metadata always take the
extent buffer start and length, so they can be simplified to take the
eb only. The fs_info can be obtained from eb too so it can be dropped
as parameter.
Added in patch "btrfs: use metadata specific helpers to simplify extent
buffer helpers".
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Mon, 24 Feb 2025 16:22:22 +0000 (16:22 +0000)]
btrfs: fix reclaimed bytes accounting after automatic block group reclaim
We are considering the used bytes counter of a block group as the amount
to update the space info's reclaim bytes counter after relocating the
block group, but this value alone is often not enough. This is because we
may have a reserved extent (or more) and in that case its size is
reflected in the reserved counter of the block group - the size of the
extent is only transferred from the reserved counter to the used counter
of the block group when the delayed ref for the extent is run - typically
when committing the transaction (or when flushing delayed refs due to
ENOSPC on space reservation). Such call chain for data extents is:
btrfs_run_delayed_refs_for_head()
run_one_delayed_ref()
run_delayed_data_ref()
alloc_reserved_file_extent()
alloc_reserved_extent()
btrfs_update_block_group()
-> transfers the extent size from the reserved
counter to the used counter
For metadata extents:
btrfs_run_delayed_refs_for_head()
run_one_delayed_ref()
run_delayed_tree_ref()
alloc_reserved_tree_block()
alloc_reserved_extent()
btrfs_update_block_group()
-> transfers the extent size from the reserved
counter to the used counter
Since relocation flushes delalloc, waits for ordered extent completion
and commits the current transaction before doing the actual relocation
work, the correct amount of reclaimed space is therefore the sum of the
"used" and "reserved" counters of the block group before we call
btrfs_relocate_chunk() at btrfs_reclaim_bgs_work().
So fix this by taking the "reserved" counter into consideration.
Fixes:
243192b67649 ("btrfs: report reclaim stats in sysfs")
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, 24 Feb 2025 15:40:26 +0000 (15:40 +0000)]
btrfs: get used bytes while holding lock at btrfs_reclaim_bgs_work()
At btrfs_reclaim_bgs_work(), we are grabbing twice the used bytes counter
of the block group while not holding the block group's spinlock. This can
result in races, reported by KCSAN and similar tools, since a concurrent
task can be updating that counter while at btrfs_update_block_group().
So avoid these races by grabbing the counter in a critical section
delimited by the block group's spinlock after setting the block group to
RO mode. This also avoids using two different values of the counter in
case it changes in between each read. This silences KCSAN and is required
for the next patch in the series too.
Fixes:
243192b67649 ("btrfs: report reclaim stats in sysfs")
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, 21 Feb 2025 16:12:15 +0000 (16:12 +0000)]
btrfs: get zone unusable bytes while holding lock at btrfs_reclaim_bgs_work()
At btrfs_reclaim_bgs_work(), we are grabbing a block group's zone unusable
bytes while not under the protection of the block group's spinlock, so
this can trigger race reports from KCSAN (or similar tools) since that
field is typically updated while holding the lock, such as at
__btrfs_add_free_space_zoned() for example.
Fix this by grabbing the zone unusable bytes while we are still in the
critical section holding the block group's spinlock, which is right above
where we are currently grabbing 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>
David Sterba [Wed, 26 Feb 2025 08:22:32 +0000 (09:22 +0100)]
btrfs: merge alloc_dummy_extent_buffer() helpers
After previous patch removing nodesize from parameters,
__alloc_dummy_extent_buffer() and alloc_dummy_extent_buffer() are
identical so we can drop one.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Wed, 26 Feb 2025 08:22:25 +0000 (09:22 +0100)]
btrfs: don't pass nodesize to __alloc_extent_buffer()
All callers pass a valid fs_info so we can read the nodesize from that
instead of passing it as parameter.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Tue, 18 Feb 2025 15:40:17 +0000 (15:40 +0000)]
btrfs: send: simplify return logic from send_set_xattr()
There's no longer any need for the 'out' label as there are no resources
to cleanup anymore in case of an error and we can directly return if
begin_cmd() fails.
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-block.git / log