| Age | Commit message (Collapse) | Author |
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Set squota incompat bit before committing the transaction that enables
the feature.
With the config CONFIG_BTRFS_ASSERT enabled, an assertion
failure occurs regarding the simple quota feature.
[5.596534] assertion failed: btrfs_fs_incompat(fs_info, SIMPLE_QUOTA), in fs/btrfs/qgroup.c:365
[5.597098] ------------[ cut here ]------------
[5.597371] kernel BUG at fs/btrfs/qgroup.c:365!
[5.597946] CPU: 1 UID: 0 PID: 268 Comm: mount Not tainted 6.13.0-rc2-00031-gf92f4749861b #146
[5.598450] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[5.599008] RIP: 0010:btrfs_read_qgroup_config+0x74d/0x7a0
[5.604303] <TASK>
[5.605230] ? btrfs_read_qgroup_config+0x74d/0x7a0
[5.605538] ? exc_invalid_op+0x56/0x70
[5.605775] ? btrfs_read_qgroup_config+0x74d/0x7a0
[5.606066] ? asm_exc_invalid_op+0x1f/0x30
[5.606441] ? btrfs_read_qgroup_config+0x74d/0x7a0
[5.606741] ? btrfs_read_qgroup_config+0x74d/0x7a0
[5.607038] ? try_to_wake_up+0x317/0x760
[5.607286] open_ctree+0xd9c/0x1710
[5.607509] btrfs_get_tree+0x58a/0x7e0
[5.608002] vfs_get_tree+0x2e/0x100
[5.608224] fc_mount+0x16/0x60
[5.608420] btrfs_get_tree+0x2f8/0x7e0
[5.608897] vfs_get_tree+0x2e/0x100
[5.609121] path_mount+0x4c8/0xbc0
[5.609538] __x64_sys_mount+0x10d/0x150
The issue can be easily reproduced using the following reproducer:
root@q:linux# cat repro.sh
set -e
mkfs.btrfs -q -f /dev/sdb
mount /dev/sdb /mnt/btrfs
btrfs quota enable -s /mnt/btrfs
umount /mnt/btrfs
mount /dev/sdb /mnt/btrfs
The issue is that when enabling quotas, at btrfs_quota_enable(), we set
BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE at fs_info->qgroup_flags and persist
it in the quota root in the item with the key BTRFS_QGROUP_STATUS_KEY, but
we only set the incompat bit BTRFS_FEATURE_INCOMPAT_SIMPLE_QUOTA after we
commit the transaction used to enable simple quotas.
This means that if after that transaction commit we unmount the filesystem
without starting and committing any other transaction, or we have a power
failure, the next time we mount the filesystem we will find the flag
BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE set in the item with the key
BTRFS_QGROUP_STATUS_KEY but we will not find the incompat bit
BTRFS_FEATURE_INCOMPAT_SIMPLE_QUOTA set in the superblock, triggering an
assertion failure at:
btrfs_read_qgroup_config() -> qgroup_read_enable_gen()
To fix this issue, set the BTRFS_FEATURE_INCOMPAT_SIMPLE_QUOTA flag
immediately after setting the BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE.
This ensures that both flags are flushed to disk within the same
transaction.
Fixes: 182940f4f4db ("btrfs: qgroup: add new quota mode for simple quotas")
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Julian Sun <sunjunchao2870@gmail.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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During swap activation we iterate over the extents of a file and we can
have many thousands of them, so we can end up in a busy loop monopolizing
a core. Avoid this by doing a voluntary reschedule after processing each
extent.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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During swap activation we iterate over the extents of a file, then do
several checks for each extent, some of which may take some significant
time such as checking if an extent is shared. Since a file can have
many thousands of extents, this can be a very slow operation and it's
currently not interruptible. I had a bug during development of a previous
patch that resulted in an infinite loop when iterating the extents, so
a core was busy looping and I couldn't cancel the operation, which is very
annoying and requires a reboot. So make the loop interruptible by checking
for fatal signals at the end of each iteration and stopping immediately if
there is one.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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When activating a swap file, to determine if an extent is shared we use
can_nocow_extent(), which ends up at btrfs_cross_ref_exist(). That helper
is meant to be quick because it's used in the NOCOW write path, when
flushing delalloc and when doing a direct IO write, however it does return
some false positives, meaning it may indicate that an extent is shared
even if it's no longer the case. For the write path this is fine, we just
do a unnecessary COW operation instead of doing a more rigorous check
which would be too heavy (calling btrfs_is_data_extent_shared()).
However when activating a swap file, the false positives simply result
in a failure, which is confusing for users/applications. One particular
case where this happens is when a data extent only has 1 reference but
that reference is not inlined in the extent item located in the extent
tree - this happens when we create more than 33 references for an extent
and then delete those 33 references plus every other non-inline reference
except one. The function check_committed_ref() assumes that if the size
of an extent item doesn't match the size of struct btrfs_extent_item
plus the size of an inline reference (plus an owner reference in case
simple quotas are enabled), then the extent is shared - that is not the
case however, we can have a single reference but it's not inlined - the
reason we do this is to be fast and avoid inspecting non-inline references
which may be located in another leaf of the extent tree, slowing down
write paths.
The following test script reproduces the bug:
$ cat test.sh
#!/bin/bash
DEV=/dev/sdi
MNT=/mnt/sdi
NUM_CLONES=50
umount $DEV &> /dev/null
run_test()
{
local sync_after_add_reflinks=$1
local sync_after_remove_reflinks=$2
mkfs.btrfs -f $DEV > /dev/null
#mkfs.xfs -f $DEV > /dev/null
mount $DEV $MNT
touch $MNT/foo
chmod 0600 $MNT/foo
# On btrfs the file must be NOCOW.
chattr +C $MNT/foo &> /dev/null
xfs_io -s -c "pwrite -b 1M 0 1M" $MNT/foo
mkswap $MNT/foo
for ((i = 1; i <= $NUM_CLONES; i++)); do
touch $MNT/foo_clone_$i
chmod 0600 $MNT/foo_clone_$i
# On btrfs the file must be NOCOW.
chattr +C $MNT/foo_clone_$i &> /dev/null
cp --reflink=always $MNT/foo $MNT/foo_clone_$i
done
if [ $sync_after_add_reflinks -ne 0 ]; then
# Flush delayed refs and commit current transaction.
sync -f $MNT
fi
# Remove the original file and all clones except the last.
rm -f $MNT/foo
for ((i = 1; i < $NUM_CLONES; i++)); do
rm -f $MNT/foo_clone_$i
done
if [ $sync_after_remove_reflinks -ne 0 ]; then
# Flush delayed refs and commit current transaction.
sync -f $MNT
fi
# Now use the last clone as a swap file. It should work since
# its extent are not shared anymore.
swapon $MNT/foo_clone_${NUM_CLONES}
swapoff $MNT/foo_clone_${NUM_CLONES}
umount $MNT
}
echo -e "\nTest without sync after creating and removing clones"
run_test 0 0
echo -e "\nTest with sync after creating clones"
run_test 1 0
echo -e "\nTest with sync after removing clones"
run_test 0 1
echo -e "\nTest with sync after creating and removing clones"
run_test 1 1
Running the test:
$ ./test.sh
Test without sync after creating and removing clones
wrote 1048576/1048576 bytes at offset 0
1 MiB, 1 ops; 0.0017 sec (556.793 MiB/sec and 556.7929 ops/sec)
Setting up swapspace version 1, size = 1020 KiB (1044480 bytes)
no label, UUID=a6b9c29e-5ef4-4689-a8ac-bc199c750f02
swapon: /mnt/sdi/foo_clone_50: swapon failed: Invalid argument
swapoff: /mnt/sdi/foo_clone_50: swapoff failed: Invalid argument
Test with sync after creating clones
wrote 1048576/1048576 bytes at offset 0
1 MiB, 1 ops; 0.0036 sec (271.739 MiB/sec and 271.7391 ops/sec)
Setting up swapspace version 1, size = 1020 KiB (1044480 bytes)
no label, UUID=5e9008d6-1f7a-4948-a1b4-3f30aba20a33
swapon: /mnt/sdi/foo_clone_50: swapon failed: Invalid argument
swapoff: /mnt/sdi/foo_clone_50: swapoff failed: Invalid argument
Test with sync after removing clones
wrote 1048576/1048576 bytes at offset 0
1 MiB, 1 ops; 0.0103 sec (96.665 MiB/sec and 96.6651 ops/sec)
Setting up swapspace version 1, size = 1020 KiB (1044480 bytes)
no label, UUID=916c2740-fa9f-4385-9f06-29c3f89e4764
Test with sync after creating and removing clones
wrote 1048576/1048576 bytes at offset 0
1 MiB, 1 ops; 0.0031 sec (314.268 MiB/sec and 314.2678 ops/sec)
Setting up swapspace version 1, size = 1020 KiB (1044480 bytes)
no label, UUID=06aab1dd-4d90-49c0-bd9f-3a8db4e2f912
swapon: /mnt/sdi/foo_clone_50: swapon failed: Invalid argument
swapoff: /mnt/sdi/foo_clone_50: swapoff failed: Invalid argument
Fix this by reworking btrfs_swap_activate() to instead of using extent
maps and checking for shared extents with can_nocow_extent(), iterate
over the inode's file extent items and use the accurate
btrfs_is_data_extent_shared().
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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When activating the swap file we flush all delalloc and wait for ordered
extent completion, so that we don't miss any delalloc and extents before
we check that the file's extent layout is usable for a swap file and
activate the swap file. We are called with the inode's VFS lock acquired,
so we won't race with buffered and direct IO writes, however we can still
race with memory mapped writes since they don't acquire the inode's VFS
lock. The race window is between flushing all delalloc and locking the
whole file's extent range, since memory mapped writes lock an extent range
with the length of a page.
Fix this by acquiring the inode's mmap lock before we flush delalloc.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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When we call btrfs_read_folio() we get an unlocked folio, so it is possible
for a different thread to concurrently modify folio->mapping. We must
check that this hasn't happened once we do have the lock.
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
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When we call btrfs_read_folio() to bring a folio uptodate, we unlock the
folio. The result of that is that a different thread can modify the
mapping (like remove it with invalidate) before we call folio_lock().
This results in an invalid page and we need to try again.
In particular, if we are relocating concurrently with aborting a
transaction, this can result in a crash like the following:
BUG: kernel NULL pointer dereference, address: 0000000000000000
PGD 0 P4D 0
Oops: 0000 [#1] SMP
CPU: 76 PID: 1411631 Comm: kworker/u322:5
Workqueue: events_unbound btrfs_reclaim_bgs_work
RIP: 0010:set_page_extent_mapped+0x20/0xb0
RSP: 0018:ffffc900516a7be8 EFLAGS: 00010246
RAX: ffffea009e851d08 RBX: ffffea009e0b1880 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffc900516a7b90 RDI: ffffea009e0b1880
RBP: 0000000003573000 R08: 0000000000000001 R09: ffff88c07fd2f3f0
R10: 0000000000000000 R11: 0000194754b575be R12: 0000000003572000
R13: 0000000003572fff R14: 0000000000100cca R15: 0000000005582fff
FS: 0000000000000000(0000) GS:ffff88c07fd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000407d00f002 CR4: 00000000007706f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<TASK>
? __die+0x78/0xc0
? page_fault_oops+0x2a8/0x3a0
? __switch_to+0x133/0x530
? wq_worker_running+0xa/0x40
? exc_page_fault+0x63/0x130
? asm_exc_page_fault+0x22/0x30
? set_page_extent_mapped+0x20/0xb0
relocate_file_extent_cluster+0x1a7/0x940
relocate_data_extent+0xaf/0x120
relocate_block_group+0x20f/0x480
btrfs_relocate_block_group+0x152/0x320
btrfs_relocate_chunk+0x3d/0x120
btrfs_reclaim_bgs_work+0x2ae/0x4e0
process_scheduled_works+0x184/0x370
worker_thread+0xc6/0x3e0
? blk_add_timer+0xb0/0xb0
kthread+0xae/0xe0
? flush_tlb_kernel_range+0x90/0x90
ret_from_fork+0x2f/0x40
? flush_tlb_kernel_range+0x90/0x90
ret_from_fork_asm+0x11/0x20
</TASK>
This occurs because cleanup_one_transaction() calls
destroy_delalloc_inodes() which calls invalidate_inode_pages2() which
takes the folio_lock before setting mapping to NULL. We fail to check
this, and subsequently call set_extent_mapping(), which assumes that
mapping != NULL (in fact it asserts that in debug mode)
Note that the "fixes" patch here is not the one that introduced the
race (the very first iteration of this code from 2009) but a more recent
change that made this particular crash happen in practice.
Fixes: e7f1326cc24e ("btrfs: set page extent mapped after read_folio in relocate_one_page")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
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When a COWing a tree block, at btrfs_cow_block(), and we have the
tracepoint trace_btrfs_cow_block() enabled and preemption is also enabled
(CONFIG_PREEMPT=y), we can trigger a use-after-free in the COWed extent
buffer while inside the tracepoint code. This is because in some paths
that call btrfs_cow_block(), such as btrfs_search_slot(), we are holding
the last reference on the extent buffer @buf so btrfs_force_cow_block()
drops the last reference on the @buf extent buffer when it calls
free_extent_buffer_stale(buf), which schedules the release of the extent
buffer with RCU. This means that if we are on a kernel with preemption,
the current task may be preempted before calling trace_btrfs_cow_block()
and the extent buffer already released by the time trace_btrfs_cow_block()
is called, resulting in a use-after-free.
Fix this by moving the trace_btrfs_cow_block() from btrfs_cow_block() to
btrfs_force_cow_block() before the COWed extent buffer is freed.
This also has a side effect of invoking the tracepoint in the tree defrag
code, at defrag.c:btrfs_realloc_node(), since btrfs_force_cow_block() is
called there, but this is fine and it was actually missing there.
Reported-by: syzbot+8517da8635307182c8a5@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/6759a9b9.050a0220.1ac542.000d.GAE@google.com/
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Fix a use-after-free in the I/O completion path for encoded reads by
using a completion instead of a wait_queue for synchronizing the
destruction of 'struct btrfs_encoded_read_private'.
Fixes: 1881fba89bd5 ("btrfs: add BTRFS_IOC_ENCODED_READ ioctl")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.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>
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unmount
During the unmount path, at close_ctree(), we first stop the cleaner
kthread, using kthread_stop() which frees the associated task_struct, and
then stop and destroy all the work queues. However after we stopped the
cleaner we may still have a worker from the delalloc_workers queue running
inode.c:submit_compressed_extents(), which calls btrfs_add_delayed_iput(),
which in turn tries to wake up the cleaner kthread - which was already
destroyed before, resulting in a use-after-free on the task_struct.
Syzbot reported this with the following stack traces:
BUG: KASAN: slab-use-after-free in __lock_acquire+0x78/0x2100 kernel/locking/lockdep.c:5089
Read of size 8 at addr ffff8880259d2818 by task kworker/u8:3/52
CPU: 1 UID: 0 PID: 52 Comm: kworker/u8:3 Not tainted 6.13.0-rc1-syzkaller-00002-gcdd30ebb1b9f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: btrfs-delalloc btrfs_work_helper
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x169/0x550 mm/kasan/report.c:489
kasan_report+0x143/0x180 mm/kasan/report.c:602
__lock_acquire+0x78/0x2100 kernel/locking/lockdep.c:5089
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline]
try_to_wake_up+0xc2/0x1470 kernel/sched/core.c:4205
submit_compressed_extents+0xdf/0x16e0 fs/btrfs/inode.c:1615
run_ordered_work fs/btrfs/async-thread.c:288 [inline]
btrfs_work_helper+0x96f/0xc40 fs/btrfs/async-thread.c:324
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310
worker_thread+0x870/0xd30 kernel/workqueue.c:3391
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
Allocated by task 2:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4104 [inline]
slab_alloc_node mm/slub.c:4153 [inline]
kmem_cache_alloc_node_noprof+0x1d9/0x380 mm/slub.c:4205
alloc_task_struct_node kernel/fork.c:180 [inline]
dup_task_struct+0x57/0x8c0 kernel/fork.c:1113
copy_process+0x5d1/0x3d50 kernel/fork.c:2225
kernel_clone+0x223/0x870 kernel/fork.c:2807
kernel_thread+0x1bc/0x240 kernel/fork.c:2869
create_kthread kernel/kthread.c:412 [inline]
kthreadd+0x60d/0x810 kernel/kthread.c:767
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Freed by task 24:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2338 [inline]
slab_free mm/slub.c:4598 [inline]
kmem_cache_free+0x195/0x410 mm/slub.c:4700
put_task_struct include/linux/sched/task.h:144 [inline]
delayed_put_task_struct+0x125/0x300 kernel/exit.c:227
rcu_do_batch kernel/rcu/tree.c:2567 [inline]
rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823
handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:554
run_ksoftirqd+0xca/0x130 kernel/softirq.c:943
smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Last potentially related work creation:
kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
__kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:544
__call_rcu_common kernel/rcu/tree.c:3086 [inline]
call_rcu+0x167/0xa70 kernel/rcu/tree.c:3190
context_switch kernel/sched/core.c:5372 [inline]
__schedule+0x1803/0x4be0 kernel/sched/core.c:6756
__schedule_loop kernel/sched/core.c:6833 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6848
schedule_timeout+0xb0/0x290 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common kernel/sched/completion.c:116 [inline]
wait_for_common kernel/sched/completion.c:127 [inline]
wait_for_completion+0x355/0x620 kernel/sched/completion.c:148
kthread_stop+0x19e/0x640 kernel/kthread.c:712
close_ctree+0x524/0xd60 fs/btrfs/disk-io.c:4328
generic_shutdown_super+0x139/0x2d0 fs/super.c:642
kill_anon_super+0x3b/0x70 fs/super.c:1237
btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2112
deactivate_locked_super+0xc4/0x130 fs/super.c:473
cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373
task_work_run+0x24f/0x310 kernel/task_work.c:239
ptrace_notify+0x2d2/0x380 kernel/signal.c:2503
ptrace_report_syscall include/linux/ptrace.h:415 [inline]
ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline]
syscall_exit_work+0xc7/0x1d0 kernel/entry/common.c:173
syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline]
syscall_exit_to_user_mode+0x24a/0x340 kernel/entry/common.c:218
do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff8880259d1e00
which belongs to the cache task_struct of size 7424
The buggy address is located 2584 bytes inside of
freed 7424-byte region [ffff8880259d1e00, ffff8880259d3b00)
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x259d0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88802f4b56c1
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801bafe500 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000040004 00000001f5000000 ffff88802f4b56c1
head: 00fff00000000040 ffff88801bafe500 dead000000000100 dead000000000122
head: 0000000000000000 0000000000040004 00000001f5000000 ffff88802f4b56c1
head: 00fff00000000003 ffffea0000967401 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 12, tgid 12 (kworker/u8:1), ts 7328037942, free_ts 0
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556
prep_new_page mm/page_alloc.c:1564 [inline]
get_page_from_freelist+0x3651/0x37a0 mm/page_alloc.c:3474
__alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4751
alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
alloc_slab_page+0x6a/0x140 mm/slub.c:2408
allocate_slab+0x5a/0x2f0 mm/slub.c:2574
new_slab mm/slub.c:2627 [inline]
___slab_alloc+0xcd1/0x14b0 mm/slub.c:3815
__slab_alloc+0x58/0xa0 mm/slub.c:3905
__slab_alloc_node mm/slub.c:3980 [inline]
slab_alloc_node mm/slub.c:4141 [inline]
kmem_cache_alloc_node_noprof+0x269/0x380 mm/slub.c:4205
alloc_task_struct_node kernel/fork.c:180 [inline]
dup_task_struct+0x57/0x8c0 kernel/fork.c:1113
copy_process+0x5d1/0x3d50 kernel/fork.c:2225
kernel_clone+0x223/0x870 kernel/fork.c:2807
user_mode_thread+0x132/0x1a0 kernel/fork.c:2885
call_usermodehelper_exec_work+0x5c/0x230 kernel/umh.c:171
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310
worker_thread+0x870/0xd30 kernel/workqueue.c:3391
page_owner free stack trace missing
Memory state around the buggy address:
ffff8880259d2700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880259d2780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880259d2800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880259d2880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880259d2900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
Fix this by flushing the delalloc workers queue before stopping the
cleaner kthread.
Reported-by: syzbot+b7cf50a0c173770dcb14@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/674ed7e8.050a0220.48a03.0031.GAE@google.com/
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Commit e546fe1da9bd ("block: Rework bio_split() return value") changed
bio_split() so that it can return errors.
Add error handling for it in btrfs_split_bio() and ultimately
btrfs_submit_chunk(). As the bio is not submitted, the bio counter must
be decremented to pair btrfs_bio_counter_inc_blocked().
Reviewed-by: John Garry <john.g.garry@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>
|
|
[BUG]
Before commit e820dbeb6ad1 ("btrfs: convert btrfs_buffered_write() to
use folios"), function prepare_one_folio() will always wait for folio
writeback to finish before returning the folio.
However commit e820dbeb6ad1 ("btrfs: convert btrfs_buffered_write() to
use folios") changed to use FGP_STABLE to do the writeback wait, but
FGP_STABLE is calling folio_wait_stable(), which only calls
folio_wait_writeback() if the address space has AS_STABLE_WRITES, which
is not set for btrfs inodes.
This means we will not wait for the folio writeback at all.
[CAUSE]
The cause is FGP_STABLE is not waiting for writeback unconditionally, but
only for address spaces with AS_STABLE_WRITES, normally such flag is set
when the super block has SB_I_STABLE_WRITES flag.
Such super block flag is set when the block device has hardware digest
support or has internal checksum requirement.
I'd argue btrfs should set such super block due to its default data
checksum behavior, but it is not set yet, so this means FGP_STABLE flag
will have no effect at all.
(For NODATASUM inodes, we can skip the waiting in theory but that should
be an optimization in the future.)
This can lead to data checksum mismatch, as we can modify the folio
while it's still under writeback, this will make the contents differ
from the contents at submission and checksum calculation.
[FIX]
Instead of fully relying on FGP_STABLE, manually do the folio writeback
waiting, until we set the address space or super flag.
Fixes: e820dbeb6ad1 ("btrfs: convert btrfs_buffered_write() to use folios")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
When activating a swap file we acquire the root's snapshot drew lock and
then check if the root is dead, failing and returning with -EPERM if it's
dead but without unlocking the root's snapshot lock. Fix this by adding
the missing unlock.
Fixes: 60021bd754c6 ("btrfs: prevent subvol with swapfile from being deleted")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-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>
|
|
[BUG]
The following reproducer can cause btrfs mount to fail:
dev="/dev/test/scratch1"
mnt1="/mnt/test"
mnt2="/mnt/scratch"
mkfs.btrfs -f $dev
mount $dev $mnt1
btrfs subvolume create $mnt1/subvol1
btrfs subvolume create $mnt1/subvol2
umount $mnt1
mount $dev $mnt1 -o subvol=subvol1
while mount -o remount,ro $mnt1; do mount -o remount,rw $mnt1; done &
bg=$!
while mount $dev $mnt2 -o subvol=subvol2; do umount $mnt2; done
kill $bg
wait
umount -R $mnt1
umount -R $mnt2
The script will fail with the following error:
mount: /mnt/scratch: /dev/mapper/test-scratch1 already mounted on /mnt/test.
dmesg(1) may have more information after failed mount system call.
umount: /mnt/test: target is busy.
umount: /mnt/scratch/: not mounted
And there is no kernel error message.
[CAUSE]
During the btrfs mount, to support mounting different subvolumes with
different RO/RW flags, we need to detect that and retry if needed:
Retry with matching RO flags if the initial mount fail with -EBUSY.
The problem is, during that retry we do not hold any super block lock
(s_umount), this means there can be a remount process changing the RO
flags of the original fs super block.
If so, we can have an EBUSY error during retry. And this time we treat
any failure as an error, without any retry and cause the above EBUSY
mount failure.
[FIX]
The current retry behavior is racy because we do not have a super block
thus no way to hold s_umount to prevent the race with remount.
Solve the root problem by allowing fc->sb_flags to mismatch from the
sb->s_flags at btrfs_get_tree_super().
Then at the re-entry point btrfs_get_tree_subvol(), manually check the
fc->s_flags against sb->s_flags, if it's a RO->RW mismatch, then
reconfigure with s_umount lock hold.
Reported-by: Enno Gotthold <egotthold@suse.com>
Reported-by: Fabian Vogt <fvogt@suse.com>
[ Special thanks for the reproducer and early analysis pointing to btrfs. ]
Fixes: f044b318675f ("btrfs: handle the ro->rw transition for mounting different subvolumes")
Link: https://bugzilla.suse.com/show_bug.cgi?id=1231836
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Lockdep doesn't like the fact that btrfs_uring_read_extent() returns to
userspace still holding the inode lock, even though we release it once
the I/O finishes. Add calls to rwsem_release() and rwsem_acquire_read() to
work round this.
Reported-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
34310c442e17 ("btrfs: add io_uring command for encoded reads (ENCODED_READ ioctl)")
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
At btrfs_ref_tree_mod() after we successfully inserted the new ref entry
(local variable 'ref') into the respective block entry's rbtree (local
variable 'be'), if we find an unexpected action of BTRFS_DROP_DELAYED_REF,
we error out and free the ref entry without removing it from the block
entry's rbtree. Then in the error path of btrfs_ref_tree_mod() we call
btrfs_free_ref_cache(), which iterates over all block entries and then
calls free_block_entry() for each one, and there we will trigger a
use-after-free when we are called against the block entry to which we
added the freed ref entry to its rbtree, since the rbtree still points
to the block entry, as we didn't remove it from the rbtree before freeing
it in the error path at btrfs_ref_tree_mod(). Fix this by removing the
new ref entry from the rbtree before freeing it.
Syzbot report this with the following stack traces:
BTRFS error (device loop0 state EA): Ref action 2, root 5, ref_root 0, parent 8564736, owner 0, offset 0, num_refs 18446744073709551615
__btrfs_mod_ref+0x7dd/0xac0 fs/btrfs/extent-tree.c:2523
update_ref_for_cow+0x9cd/0x11f0 fs/btrfs/ctree.c:512
btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594
btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754
btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116
btrfs_insert_empty_items+0x9c/0x1a0 fs/btrfs/ctree.c:4314
btrfs_insert_empty_item fs/btrfs/ctree.h:669 [inline]
btrfs_insert_orphan_item+0x1f1/0x320 fs/btrfs/orphan.c:23
btrfs_orphan_add+0x6d/0x1a0 fs/btrfs/inode.c:3482
btrfs_unlink+0x267/0x350 fs/btrfs/inode.c:4293
vfs_unlink+0x365/0x650 fs/namei.c:4469
do_unlinkat+0x4ae/0x830 fs/namei.c:4533
__do_sys_unlinkat fs/namei.c:4576 [inline]
__se_sys_unlinkat fs/namei.c:4569 [inline]
__x64_sys_unlinkat+0xcc/0xf0 fs/namei.c:4569
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
BTRFS error (device loop0 state EA): Ref action 1, root 5, ref_root 5, parent 0, owner 260, offset 0, num_refs 1
__btrfs_mod_ref+0x76b/0xac0 fs/btrfs/extent-tree.c:2521
update_ref_for_cow+0x96a/0x11f0
btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594
btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754
btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116
btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:411
__btrfs_update_delayed_inode+0x1e7/0xb90 fs/btrfs/delayed-inode.c:1030
btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1114 [inline]
__btrfs_commit_inode_delayed_items+0x2318/0x24a0 fs/btrfs/delayed-inode.c:1137
__btrfs_run_delayed_items+0x213/0x490 fs/btrfs/delayed-inode.c:1171
btrfs_commit_transaction+0x8a8/0x3740 fs/btrfs/transaction.c:2313
prepare_to_relocate+0x3c4/0x4c0 fs/btrfs/relocation.c:3586
relocate_block_group+0x16c/0xd40 fs/btrfs/relocation.c:3611
btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4081
btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3377
__btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4161
btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4538
BTRFS error (device loop0 state EA): Ref action 2, root 5, ref_root 0, parent 8564736, owner 0, offset 0, num_refs 18446744073709551615
__btrfs_mod_ref+0x7dd/0xac0 fs/btrfs/extent-tree.c:2523
update_ref_for_cow+0x9cd/0x11f0 fs/btrfs/ctree.c:512
btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594
btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754
btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116
btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:411
__btrfs_update_delayed_inode+0x1e7/0xb90 fs/btrfs/delayed-inode.c:1030
btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1114 [inline]
__btrfs_commit_inode_delayed_items+0x2318/0x24a0 fs/btrfs/delayed-inode.c:1137
__btrfs_run_delayed_items+0x213/0x490 fs/btrfs/delayed-inode.c:1171
btrfs_commit_transaction+0x8a8/0x3740 fs/btrfs/transaction.c:2313
prepare_to_relocate+0x3c4/0x4c0 fs/btrfs/relocation.c:3586
relocate_block_group+0x16c/0xd40 fs/btrfs/relocation.c:3611
btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4081
btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3377
__btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4161
btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4538
==================================================================
BUG: KASAN: slab-use-after-free in rb_first+0x69/0x70 lib/rbtree.c:473
Read of size 8 at addr ffff888042d1af38 by task syz.0.0/5329
CPU: 0 UID: 0 PID: 5329 Comm: syz.0.0 Not tainted 6.12.0-rc7-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x169/0x550 mm/kasan/report.c:488
kasan_report+0x143/0x180 mm/kasan/report.c:601
rb_first+0x69/0x70 lib/rbtree.c:473
free_block_entry+0x78/0x230 fs/btrfs/ref-verify.c:248
btrfs_free_ref_cache+0xa3/0x100 fs/btrfs/ref-verify.c:917
btrfs_ref_tree_mod+0x139f/0x15e0 fs/btrfs/ref-verify.c:898
btrfs_free_extent+0x33c/0x380 fs/btrfs/extent-tree.c:3544
__btrfs_mod_ref+0x7dd/0xac0 fs/btrfs/extent-tree.c:2523
update_ref_for_cow+0x9cd/0x11f0 fs/btrfs/ctree.c:512
btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594
btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754
btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116
btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:411
__btrfs_update_delayed_inode+0x1e7/0xb90 fs/btrfs/delayed-inode.c:1030
btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1114 [inline]
__btrfs_commit_inode_delayed_items+0x2318/0x24a0 fs/btrfs/delayed-inode.c:1137
__btrfs_run_delayed_items+0x213/0x490 fs/btrfs/delayed-inode.c:1171
btrfs_commit_transaction+0x8a8/0x3740 fs/btrfs/transaction.c:2313
prepare_to_relocate+0x3c4/0x4c0 fs/btrfs/relocation.c:3586
relocate_block_group+0x16c/0xd40 fs/btrfs/relocation.c:3611
btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4081
btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3377
__btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4161
btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4538
btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3673
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f996df7e719
RSP: 002b:00007f996ede7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f996e135f80 RCX: 00007f996df7e719
RDX: 0000000020000180 RSI: 00000000c4009420 RDI: 0000000000000004
RBP: 00007f996dff139e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f996e135f80 R15: 00007fff79f32e68
</TASK>
Allocated by task 5329:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:257 [inline]
__kmalloc_cache_noprof+0x19c/0x2c0 mm/slub.c:4295
kmalloc_noprof include/linux/slab.h:878 [inline]
kzalloc_noprof include/linux/slab.h:1014 [inline]
btrfs_ref_tree_mod+0x264/0x15e0 fs/btrfs/ref-verify.c:701
btrfs_free_extent+0x33c/0x380 fs/btrfs/extent-tree.c:3544
__btrfs_mod_ref+0x7dd/0xac0 fs/btrfs/extent-tree.c:2523
update_ref_for_cow+0x9cd/0x11f0 fs/btrfs/ctree.c:512
btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594
btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754
btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116
btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:411
__btrfs_update_delayed_inode+0x1e7/0xb90 fs/btrfs/delayed-inode.c:1030
btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1114 [inline]
__btrfs_commit_inode_delayed_items+0x2318/0x24a0 fs/btrfs/delayed-inode.c:1137
__btrfs_run_delayed_items+0x213/0x490 fs/btrfs/delayed-inode.c:1171
btrfs_commit_transaction+0x8a8/0x3740 fs/btrfs/transaction.c:2313
prepare_to_relocate+0x3c4/0x4c0 fs/btrfs/relocation.c:3586
relocate_block_group+0x16c/0xd40 fs/btrfs/relocation.c:3611
btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4081
btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3377
__btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4161
btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4538
btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3673
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 5329:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:2342 [inline]
slab_free mm/slub.c:4579 [inline]
kfree+0x1a0/0x440 mm/slub.c:4727
btrfs_ref_tree_mod+0x136c/0x15e0
btrfs_free_extent+0x33c/0x380 fs/btrfs/extent-tree.c:3544
__btrfs_mod_ref+0x7dd/0xac0 fs/btrfs/extent-tree.c:2523
update_ref_for_cow+0x9cd/0x11f0 fs/btrfs/ctree.c:512
btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594
btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754
btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116
btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:411
__btrfs_update_delayed_inode+0x1e7/0xb90 fs/btrfs/delayed-inode.c:1030
btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1114 [inline]
__btrfs_commit_inode_delayed_items+0x2318/0x24a0 fs/btrfs/delayed-inode.c:1137
__btrfs_run_delayed_items+0x213/0x490 fs/btrfs/delayed-inode.c:1171
btrfs_commit_transaction+0x8a8/0x3740 fs/btrfs/transaction.c:2313
prepare_to_relocate+0x3c4/0x4c0 fs/btrfs/relocation.c:3586
relocate_block_group+0x16c/0xd40 fs/btrfs/relocation.c:3611
btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4081
btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3377
__btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4161
btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4538
btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3673
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff888042d1af00
which belongs to the cache kmalloc-64 of size 64
The buggy address is located 56 bytes inside of
freed 64-byte region [ffff888042d1af00, ffff888042d1af40)
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x42d1a
anon flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000000 ffff88801ac418c0 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000200020 00000001f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5055, tgid 5055 (dhcpcd-run-hook), ts 40377240074, free_ts 40376848335
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1541
prep_new_page mm/page_alloc.c:1549 [inline]
get_page_from_freelist+0x3649/0x3790 mm/page_alloc.c:3459
__alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4735
alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
alloc_slab_page+0x6a/0x140 mm/slub.c:2412
allocate_slab+0x5a/0x2f0 mm/slub.c:2578
new_slab mm/slub.c:2631 [inline]
___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818
__slab_alloc+0x58/0xa0 mm/slub.c:3908
__slab_alloc_node mm/slub.c:3961 [inline]
slab_alloc_node mm/slub.c:4122 [inline]
__do_kmalloc_node mm/slub.c:4263 [inline]
__kmalloc_noprof+0x25a/0x400 mm/slub.c:4276
kmalloc_noprof include/linux/slab.h:882 [inline]
kzalloc_noprof include/linux/slab.h:1014 [inline]
tomoyo_encode2 security/tomoyo/realpath.c:45 [inline]
tomoyo_encode+0x26f/0x540 security/tomoyo/realpath.c:80
tomoyo_realpath_from_path+0x59e/0x5e0 security/tomoyo/realpath.c:283
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_check_open_permission+0x255/0x500 security/tomoyo/file.c:771
security_file_open+0x777/0x990 security/security.c:3109
do_dentry_open+0x369/0x1460 fs/open.c:945
vfs_open+0x3e/0x330 fs/open.c:1088
do_open fs/namei.c:3774 [inline]
path_openat+0x2c84/0x3590 fs/namei.c:3933
page last free pid 5055 tgid 5055 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1112 [inline]
free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2642
free_pipe_info+0x300/0x390 fs/pipe.c:860
put_pipe_info fs/pipe.c:719 [inline]
pipe_release+0x245/0x320 fs/pipe.c:742
__fput+0x23f/0x880 fs/file_table.c:431
__do_sys_close fs/open.c:1567 [inline]
__se_sys_close fs/open.c:1552 [inline]
__x64_sys_close+0x7f/0x110 fs/open.c:1552
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffff888042d1ae00: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff888042d1ae80: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
>ffff888042d1af00: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
^
ffff888042d1af80: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
ffff888042d1b000: 00 00 00 00 00 fc fc 00 00 00 00 00 fc fc 00 00
Reported-by: syzbot+7325f164162e200000c1@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/673723eb.050a0220.1324f8.00a8.GAE@google.com/T/#u
Fixes: fd708b81d972 ("Btrfs: add a extent ref verify tool")
CC: stable@vger.kernel.org # 4.19+
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>
|
|
Syzbot reports a null-ptr-deref in btrfs_search_slot().
The reproducer is using rescue=ibadroots, and the extent tree root is
corrupted thus the extent tree is NULL.
When scrub tries to search the extent tree to gather the needed extent
info, btrfs_search_slot() doesn't check if the target root is NULL or
not, resulting the null-ptr-deref.
Add sanity check for btrfs root before using it in btrfs_search_slot().
Reported-by: syzbot+3030e17bd57a73d39bd7@syzkaller.appspotmail.com
Fixes: 42437a6386ff ("btrfs: introduce mount option rescue=ignorebadroots")
Link: https://syzkaller.appspot.com/bug?extid=3030e17bd57a73d39bd7
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Tested-by: syzbot+3030e17bd57a73d39bd7@syzkaller.appspotmail.com
Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
When checking for delayed refs when verifying if there are cross
references for a data extent, we stop if the path has nowait set and we
can't try lock the delayed ref head's mutex, returning -EAGAIN with the
goal of making a write fallback to a blocking context. However we ignore
the -EAGAIN at btrfs_cross_ref_exist() when check_delayed_ref() returns
it, and keep looping instead of immediately returning the -EAGAIN to the
caller.
Fix this by not looping if we get -EAGAIN and we have a nowait path.
Fixes: 26ce91144631 ("btrfs: make can_nocow_extent nowait compatible")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
CONFIG_BTRFS_EXPERIMENTAL=y
We are advertising experimental features through sysfs if
CONFIG_BTRFS_DEBUG is set, without looking if CONFIG_BTRFS_EXPERIMENTAL
is set. This is wrong as it will result in reporting experimental
features as supported when CONFIG_BTRFS_EXPERIMENTAL is not set but
CONFIG_BTRFS_DEBUG is set.
Fix this by checking for CONFIG_BTRFS_EXPERIMENTAL instead of
CONFIG_BTRFS_DEBUG.
Fixes: 67cd3f221769 ("btrfs: split out CONFIG_BTRFS_EXPERIMENTAL from CONFIG_BTRFS_DEBUG")
Reviewed-by: Neal Gompa <neal@gompa.dev>
Reviewed-by: Qu Wenruo <wqu@suse.com>
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>
|
|
When running a workload with fsstress and duperemove (generic/561) we can
hit a deadlock related to transaction commits and locking extent ranges,
as described below.
Task A hanging during a transaction commit, waiting for all other writers
to complete:
[178317.334817] INFO: task fsstress:555623 blocked for more than 120 seconds.
[178317.335693] Not tainted 6.12.0-rc6-btrfs-next-179+ #1
[178317.336528] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[178317.337673] task:fsstress state:D stack:0 pid:555623 tgid:555623 ppid:555620 flags:0x00004002
[178317.337679] Call Trace:
[178317.337681] <TASK>
[178317.337685] __schedule+0x364/0xbe0
[178317.337691] schedule+0x26/0xa0
[178317.337695] btrfs_commit_transaction+0x5c5/0x1050 [btrfs]
[178317.337769] ? start_transaction+0xc4/0x800 [btrfs]
[178317.337815] ? __pfx_autoremove_wake_function+0x10/0x10
[178317.337819] btrfs_mksubvol+0x381/0x640 [btrfs]
[178317.337878] btrfs_mksnapshot+0x7a/0xb0 [btrfs]
[178317.337935] __btrfs_ioctl_snap_create+0x1bb/0x1d0 [btrfs]
[178317.337995] btrfs_ioctl_snap_create_v2+0x103/0x130 [btrfs]
[178317.338053] btrfs_ioctl+0x29b/0x2a90 [btrfs]
[178317.338118] ? kmem_cache_alloc_noprof+0x5f/0x2c0
[178317.338126] ? getname_flags+0x45/0x1f0
[178317.338133] ? _raw_spin_unlock+0x15/0x30
[178317.338145] ? __x64_sys_ioctl+0x88/0xc0
[178317.338149] __x64_sys_ioctl+0x88/0xc0
[178317.338152] do_syscall_64+0x4a/0x110
[178317.338160] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[178317.338190] RIP: 0033:0x7f13c28e271b
Which corresponds to line 2361 of transaction.c:
$ cat -n fs/btrfs/transaction.c
(...)
2162 int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
2163 {
(...)
2349 spin_lock(&fs_info->trans_lock);
2350 add_pending_snapshot(trans);
2351 cur_trans->state = TRANS_STATE_COMMIT_DOING;
2352 spin_unlock(&fs_info->trans_lock);
2353
2354 /*
2355 * The thread has started/joined the transaction thus it holds the
2356 * lockdep map as a reader. It has to release it before acquiring the
2357 * lockdep map as a writer.
2358 */
2359 btrfs_lockdep_release(fs_info, btrfs_trans_num_writers);
2360 btrfs_might_wait_for_event(fs_info, btrfs_trans_num_writers);
2361 wait_event(cur_trans->writer_wait,
2362 atomic_read(&cur_trans->num_writers) == 1);
(...)
The transaction is in the TRANS_STATE_COMMIT_DOING state and so it's
waiting for all other existing writers to complete and release their
transaction handle.
Task B is running ordered extent completion and blocked waiting to lock an
extent range in an inode's io tree:
[178317.327411] INFO: task kworker/u48:8:554545 blocked for more than 120 seconds.
[178317.328630] Not tainted 6.12.0-rc6-btrfs-next-179+ #1
[178317.329635] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[178317.330872] task:kworker/u48:8 state:D stack:0 pid:554545 tgid:554545 ppid:2 flags:0x00004000
[178317.330878] Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
[178317.330944] Call Trace:
[178317.330945] <TASK>
[178317.330947] __schedule+0x364/0xbe0
[178317.330952] schedule+0x26/0xa0
[178317.330955] __lock_extent+0x337/0x3a0 [btrfs]
[178317.331014] ? __pfx_autoremove_wake_function+0x10/0x10
[178317.331017] btrfs_finish_one_ordered+0x47a/0xaa0 [btrfs]
[178317.331074] ? psi_group_change+0x132/0x2d0
[178317.331078] btrfs_work_helper+0xbd/0x370 [btrfs]
[178317.331140] process_scheduled_works+0xd3/0x460
[178317.331144] ? __pfx_worker_thread+0x10/0x10
[178317.331146] worker_thread+0x121/0x250
[178317.331149] ? __pfx_worker_thread+0x10/0x10
[178317.331151] kthread+0xe9/0x120
[178317.331154] ? __pfx_kthread+0x10/0x10
[178317.331157] ret_from_fork+0x2d/0x50
[178317.331159] ? __pfx_kthread+0x10/0x10
[178317.331162] ret_from_fork_asm+0x1a/0x30
This extent range locking happens after joining the current transaction,
so task A is waiting for task B to release its transaction handle
(decrementing the transaction's num_writers counter).
Task C while doing a fiemap it tries to join the current transaction:
[242682.812815] task:pool state:D stack:0 pid:560767 tgid:560724 ppid:555622 flags:0x00004006
[242682.812827] Call Trace:
[242682.812856] <TASK>
[242682.812864] __schedule+0x364/0xbe0
[242682.812879] ? _raw_spin_unlock_irqrestore+0x23/0x40
[242682.812897] schedule+0x26/0xa0
[242682.812909] wait_current_trans+0xd6/0x130 [btrfs]
[242682.813148] ? __pfx_autoremove_wake_function+0x10/0x10
[242682.813162] start_transaction+0x3d4/0x800 [btrfs]
[242682.813399] btrfs_is_data_extent_shared+0xd2/0x440 [btrfs]
[242682.813723] fiemap_process_hole+0x2a2/0x300 [btrfs]
[242682.813995] extent_fiemap+0x9b8/0xb80 [btrfs]
[242682.814249] btrfs_fiemap+0x78/0xc0 [btrfs]
[242682.814501] do_vfs_ioctl+0x2db/0xa50
[242682.814519] __x64_sys_ioctl+0x6a/0xc0
[242682.814531] do_syscall_64+0x4a/0x110
[242682.814544] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[242682.814556] RIP: 0033:0x7efff595e71b
It tries to join the current transaction, but it can't because the
transaction is in the TRANS_STATE_COMMIT_DOING state, so
join_transaction() returns -EBUSY to start_transaction() and makes it
wait for the current transaction to complete. And while it's waiting
for the transaction to complete, it's holding an extent range locked
in the same inode that task B is operating, which causes a deadlock
between these 3 tasks. The extent range for the inode was locked at
the start of the fiemap operation, early at extent_fiemap().
In short these tasks deadlock because:
1) Task A is waiting for task B to release its transaction handle;
2) Task B is waiting to lock an extent range for an inode while holding a
transaction handle open;
3) Task C is waiting for the current transaction to complete (for task A
to finish the transaction commit) while holding the extent range for
the inode locked, so task B can't progress and release its transaction
handle.
This results in an ABBA deadlock involving transaction commits and extent
locks. Extent locks are higher level locks, like inode VFS locks, and
should always be acquired before joining or starting a transaction, but
recently commit 2206265f41e9 ("btrfs: remove code duplication in ordered
extent finishing") accidentally changed btrfs_finish_one_ordered() to do
the transaction join before locking the extent range.
Fix this by making sure that btrfs_finish_one_ordered() always locks the
extent before joining a transaction and add an explicit comment about the
need for this order.
Fixes: 2206265f41e9 ("btrfs: remove code duplication in ordered extent finishing")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Shinichiro reported the following use-after free that sometimes is
happening in our CI system when running fstests' btrfs/284 on a TCMU
runner device:
BUG: KASAN: slab-use-after-free in lock_release+0x708/0x780
Read of size 8 at addr ffff888106a83f18 by task kworker/u80:6/219
CPU: 8 UID: 0 PID: 219 Comm: kworker/u80:6 Not tainted 6.12.0-rc6-kts+ #15
Hardware name: Supermicro Super Server/X11SPi-TF, BIOS 3.3 02/21/2020
Workqueue: btrfs-endio btrfs_end_bio_work [btrfs]
Call Trace:
<TASK>
dump_stack_lvl+0x6e/0xa0
? lock_release+0x708/0x780
print_report+0x174/0x505
? lock_release+0x708/0x780
? __virt_addr_valid+0x224/0x410
? lock_release+0x708/0x780
kasan_report+0xda/0x1b0
? lock_release+0x708/0x780
? __wake_up+0x44/0x60
lock_release+0x708/0x780
? __pfx_lock_release+0x10/0x10
? __pfx_do_raw_spin_lock+0x10/0x10
? lock_is_held_type+0x9a/0x110
_raw_spin_unlock_irqrestore+0x1f/0x60
__wake_up+0x44/0x60
btrfs_encoded_read_endio+0x14b/0x190 [btrfs]
btrfs_check_read_bio+0x8d9/0x1360 [btrfs]
? lock_release+0x1b0/0x780
? trace_lock_acquire+0x12f/0x1a0
? __pfx_btrfs_check_read_bio+0x10/0x10 [btrfs]
? process_one_work+0x7e3/0x1460
? lock_acquire+0x31/0xc0
? process_one_work+0x7e3/0x1460
process_one_work+0x85c/0x1460
? __pfx_process_one_work+0x10/0x10
? assign_work+0x16c/0x240
worker_thread+0x5e6/0xfc0
? __pfx_worker_thread+0x10/0x10
kthread+0x2c3/0x3a0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x31/0x70
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 3661:
kasan_save_stack+0x30/0x50
kasan_save_track+0x14/0x30
__kasan_kmalloc+0xaa/0xb0
btrfs_encoded_read_regular_fill_pages+0x16c/0x6d0 [btrfs]
send_extent_data+0xf0f/0x24a0 [btrfs]
process_extent+0x48a/0x1830 [btrfs]
changed_cb+0x178b/0x2ea0 [btrfs]
btrfs_ioctl_send+0x3bf9/0x5c20 [btrfs]
_btrfs_ioctl_send+0x117/0x330 [btrfs]
btrfs_ioctl+0x184a/0x60a0 [btrfs]
__x64_sys_ioctl+0x12e/0x1a0
do_syscall_64+0x95/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Freed by task 3661:
kasan_save_stack+0x30/0x50
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x70
__kasan_slab_free+0x4f/0x70
kfree+0x143/0x490
btrfs_encoded_read_regular_fill_pages+0x531/0x6d0 [btrfs]
send_extent_data+0xf0f/0x24a0 [btrfs]
process_extent+0x48a/0x1830 [btrfs]
changed_cb+0x178b/0x2ea0 [btrfs]
btrfs_ioctl_send+0x3bf9/0x5c20 [btrfs]
_btrfs_ioctl_send+0x117/0x330 [btrfs]
btrfs_ioctl+0x184a/0x60a0 [btrfs]
__x64_sys_ioctl+0x12e/0x1a0
do_syscall_64+0x95/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The buggy address belongs to the object at ffff888106a83f00
which belongs to the cache kmalloc-rnd-07-96 of size 96
The buggy address is located 24 bytes inside of
freed 96-byte region [ffff888106a83f00, ffff888106a83f60)
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888106a83800 pfn:0x106a83
flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff)
page_type: f5(slab)
raw: 0017ffffc0000000 ffff888100053680 ffffea0004917200 0000000000000004
raw: ffff888106a83800 0000000080200019 00000001f5000000 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888106a83e00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
ffff888106a83e80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff888106a83f00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
^
ffff888106a83f80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
ffff888106a84000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
Further analyzing the trace and the crash dump's vmcore file shows that
the wake_up() call in btrfs_encoded_read_endio() is calling wake_up() on
the wait_queue that is in the private data passed to the end_io handler.
Commit 4ff47df40447 ("btrfs: move priv off stack in
btrfs_encoded_read_regular_fill_pages()") moved 'struct
btrfs_encoded_read_private' off the stack.
Before that commit one can see a corruption of the private data when
analyzing the vmcore after a crash:
*(struct btrfs_encoded_read_private *)0xffff88815626eec8 = {
.wait = (wait_queue_head_t){
.lock = (spinlock_t){
.rlock = (struct raw_spinlock){
.raw_lock = (arch_spinlock_t){
.val = (atomic_t){
.counter = (int)-2005885696,
},
.locked = (u8)0,
.pending = (u8)157,
.locked_pending = (u16)40192,
.tail = (u16)34928,
},
.magic = (unsigned int)536325682,
.owner_cpu = (unsigned int)29,
.owner = (void *)__SCT__tp_func_btrfs_transaction_commit+0x0 = 0x0,
.dep_map = (struct lockdep_map){
.key = (struct lock_class_key *)0xffff8881575a3b6c,
.class_cache = (struct lock_class *[2]){ 0xffff8882a71985c0, 0xffffea00066f5d40 },
.name = (const char *)0xffff88815626f100 = "",
.wait_type_outer = (u8)37,
.wait_type_inner = (u8)178,
.lock_type = (u8)154,
},
},
.__padding = (u8 [24]){ 0, 157, 112, 136, 50, 174, 247, 31, 29 },
.dep_map = (struct lockdep_map){
.key = (struct lock_class_key *)0xffff8881575a3b6c,
.class_cache = (struct lock_class *[2]){ 0xffff8882a71985c0, 0xffffea00066f5d40 },
.name = (const char *)0xffff88815626f100 = "",
.wait_type_outer = (u8)37,
.wait_type_inner = (u8)178,
.lock_type = (u8)154,
},
},
.head = (struct list_head){
.next = (struct list_head *)0x112cca,
.prev = (struct list_head *)0x47,
},
},
.pending = (atomic_t){
.counter = (int)-1491499288,
},
.status = (blk_status_t)130,
}
Here we can see several indicators of in-memory data corruption, e.g. the
large negative atomic values of ->pending or
->wait->lock->rlock->raw_lock->val, as well as the bogus spinlock magic
0x1ff7ae32 (decimal 536325682 above) instead of 0xdead4ead or the bogus
pointer values for ->wait->head.
To fix this, change atomic_dec_return() to atomic_dec_and_test() to fix the
corruption, as atomic_dec_return() is defined as two instructions on
x86_64, whereas atomic_dec_and_test() is defined as a single atomic
operation. This can lead to a situation where counter value is already
decremented but the if statement in btrfs_encoded_read_endio() is not
completely processed, i.e. the 0 test has not completed. If another thread
continues executing btrfs_encoded_read_regular_fill_pages() the
atomic_dec_return() there can see an already updated ->pending counter and
continues by freeing the private data. Continuing in the endio handler the
test for 0 succeeds and the wait_queue is woken up, resulting in a
use-after-free.
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Suggested-by: Damien Le Moal <Damien.LeMoal@wdc.com>
Fixes: 1881fba89bd5 ("btrfs: add BTRFS_IOC_ENCODED_READ ioctl")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.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>
|
|
We're checking if the send root is read-only without being under the
protection of the root's root_item_lock spinlock, which is what protects
the root's flags when clearing the read-only flag, done at
btrfs_ioctl_subvol_setflags(). Furthermore, it should be done in the
same critical section that increments the root's send_in_progress counter,
as btrfs_ioctl_subvol_setflags() clears the read-only flag in the same
critical section that checks the counter's value.
So fix this by moving the read-only check under the critical section
delimited by the root's root_item_lock which also increments the root's
send_in_progress counter.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
We're checking if the send root is dead without the protection of the
root's root_item_lock spinlock, which is what protects the root's flags.
The inverse, setting the dead flag on a root, is done under the protection
of that lock, at btrfs_delete_subvolume(). Also checking and updating the
root's send_in_progress counter is supposed to be done in the same
critical section as checking for or setting the root dead flag, so that
these operations are done atomically as a single step (which is correctly
done by btrfs_delete_subvolume()).
So fix this by checking if the send root is dead in the same critical
section that updates the send_in_progress counter, which is protected by
the root's root_item_lock spinlock.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Smatch complains about possibly dereferencing a NULL fs_info at
btrfs_folio_end_lock_bitmap():
fs/btrfs/subpage.c:332 btrfs_folio_end_lock_bitmap() warn: variable dereferenced before check 'fs_info' (see line 326)
because we access fs_info to set the 'start_bit' variable before doing the
check for a NULL fs_info.
However fs_info is never NULL, since in the only caller of
btrfs_folio_end_lock_bitmap() is extent_writepage(), where we have an
inode which always as a non-NULL fs_info.
So remove the check for a NULL fs_info at btrfs_folio_end_lock_bitmap().
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>
|
|
Smatch complains about calling PTR_ERR() against a NULL pointer:
fs/btrfs/super.c:2272 btrfs_control_ioctl() warn: passing zero to 'PTR_ERR'
Fix this by calling PTR_ERR() against the device pointer only if it
contains 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>
|
|
REQ_OP_ZONE_APPNED -> REQ_OP_ZONE_APPEND.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Change the control flow of btrfs_encoded_read() so that it doesn't call
free_extent_map() when we know that this has already been done.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Suggested-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
There's no point in having a 'snapshot_force_cow' variable to track if we
need to decrement the root->snapshot_force_cow counter, as we never jump
to the 'out' label after incrementing the counter. Simplify this by
removing the variable and always decrementing the counter before the 'out'
label, right after the call to btrfs_mksubvol().
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>
|
|
On x86_64 and a release kernel, there's a 4 bytes hole in the structure
after the ref count field:
struct btrfs_delayed_node {
u64 inode_id; /* 0 8 */
u64 bytes_reserved; /* 8 8 */
struct btrfs_root * root; /* 16 8 */
struct list_head n_list; /* 24 16 */
struct list_head p_list; /* 40 16 */
struct rb_root_cached ins_root; /* 56 16 */
/* --- cacheline 1 boundary (64 bytes) was 8 bytes ago --- */
struct rb_root_cached del_root; /* 72 16 */
struct mutex mutex; /* 88 32 */
struct btrfs_inode_item inode_item; /* 120 160 */
/* --- cacheline 4 boundary (256 bytes) was 24 bytes ago --- */
refcount_t refs; /* 280 4 */
/* XXX 4 bytes hole, try to pack */
u64 index_cnt; /* 288 8 */
long unsigned int flags; /* 296 8 */
int count; /* 304 4 */
u32 curr_index_batch_size; /* 308 4 */
u32 index_item_leaves; /* 312 4 */
/* size: 320, cachelines: 5, members: 15 */
/* sum members: 312, holes: 1, sum holes: 4 */
/* padding: 4 */
};
Move the 'count' field, which is 4 bytes long, to just below the ref count
field, so we eliminate the hole and reduce the structure size from 320
bytes down to 312 bytes:
struct btrfs_delayed_node {
u64 inode_id; /* 0 8 */
u64 bytes_reserved; /* 8 8 */
struct btrfs_root * root; /* 16 8 */
struct list_head n_list; /* 24 16 */
struct list_head p_list; /* 40 16 */
struct rb_root_cached ins_root; /* 56 16 */
/* --- cacheline 1 boundary (64 bytes) was 8 bytes ago --- */
struct rb_root_cached del_root; /* 72 16 */
struct mutex mutex; /* 88 32 */
struct btrfs_inode_item inode_item; /* 120 160 */
/* --- cacheline 4 boundary (256 bytes) was 24 bytes ago --- */
refcount_t refs; /* 280 4 */
int count; /* 284 4 */
u64 index_cnt; /* 288 8 */
long unsigned int flags; /* 296 8 */
u32 curr_index_batch_size; /* 304 4 */
u32 index_item_leaves; /* 308 4 */
/* size: 312, cachelines: 5, members: 15 */
/* last cacheline: 56 bytes */
};
This now allows to have 13 delayed nodes per 4K page instead of 12.
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>
|
|
The comment refers to a list in the respective delayed ref head that no
longer exists (ref_list), it was replaced with a rbtree (ref_tree) in
commit 0e0adbcfdc90 ("btrfs: track refs in a rb_tree instead of a list").
So update the stale comment to refer to the rbtree instead of the old
list.
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>
|
|
Add a new unprivileged ioctl that will let the command
'btrfs subvolume sync' work without the (privileged) SEARCH_TREE ioctl.
There are several modes of operation, where the most common ones are to
wait on a specific subvolume or all currently queued for cleaning. This
is utilized e.g. in backup applications that delete subvolumes and wait
until they're cleaned to check for remaining space.
The other modes are for flexibility, e.g. for monitoring or
checkpoints in the queue of deleted subvolumes, again without the need
to use SEARCH_TREE.
Notes:
- waiting is interruptible, the timeout is set to 1 second and is not
configurable
- repeated calls to the ioctl see a different state, so this is
inherently racy when using e.g. the count or peek next/last
Use cases:
- a subvolume A was deleted, wait for cleaning (WAIT_FOR_ONE)
- a bunch of subvolumes were deleted, wait for all (WAIT_FOR_QUEUED or
PEEK_LAST + WAIT_FOR_ONE)
- count how many are queued (not blocking), for monitoring purposes
- report progress (PEEK_NEXT), may miss some if cleaning is quick
- own waiting in user space (PEEK_LAST until it's 0)
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Simplify tracking of the range processed by using cur_alloc_size only to
store the reserved part that may fail to the allocated extent. Remove
the ram_size as well since it is always equal to cur_alloc_size in the
context. Advance the start in normal path until extent allocation
succeeds and keep the start unchanged in the error handling path.
Passed the fstest generic/475 test for a hundred times with quota
enabled. And a modified generic/475 test by removing the sleep time
for a hundred times. About one tenth of the tests do enter the error
handling path due to fail to reserve extent.
Suggested-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Haisu Wang <haisuwang@tencent.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Remove conditional path allocation from btrfs_read_locked_inode(). Add
an ASSERT(path) to indicate it should never be called with a NULL path.
Call btrfs_read_locked_inode() directly from btrfs_iget(). This causes
code duplication between btrfs_iget() and btrfs_iget_path(), but I
think this is justifiable as it removes the need for conditionally
allocating the path inside of btrfs_read_locked_inode(). This makes the
code easier to reason about and makes it clear who has the
responsibility of allocating and freeing the path.
Signed-off-by: Leo Martins <loemra.dev@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Move btrfs_add_inode_to_root() so it can be called from
btrfs_read_locked_inode(), no changes were made to the function.
Move cleanup code from btrfs_iget_path() to btrfs_read_locked_inode.
This improves readability and improves a leaky abstraction. Previously
btrfs_iget_path() had to handle a positive error case as a result of a
call to btrfs_search_slot(), but it makes more sense to handle this
closer to the source of the call.
Signed-off-by: Leo Martins <loemra.dev@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
When the taks that submitted a request is dying, a task work for that
request might get run by a kernel thread or even worse by a half
dismantled task. We can't just cancel the task work without running the
callback as the cmd might need to do some clean up, so pass a flag
instead. If set, it's not safe to access any task resources and the
callback is expected to cancel the cmd ASAP.
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Add struct io_btrfs_cmd as a wrapper type for io_uring_cmd_to_pdu(),
rather than using a raw pointer.
Suggested-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Add an io_uring command for encoded reads, using the same interface as
the existing BTRFS_IOC_ENCODED_READ ioctl.
btrfs_uring_encoded_read() is an io_uring version of
btrfs_ioctl_encoded_read(), which validates the user input and calls
btrfs_encoded_read() to read the appropriate metadata. If we determine
that we need to read an extent from disk, we call
btrfs_encoded_read_regular_fill_pages() through
btrfs_uring_read_extent() to prepare the bio.
The existing btrfs_encoded_read_regular_fill_pages() is changed so that
if it is passed a valid uring_ctx, rather than waking up any waiting
threads it calls btrfs_uring_read_extent_endio(). This in turn copies
the read data back to userspace, and calls io_uring_cmd_done() to
complete the io_uring command.
Because we're potentially doing a non-blocking read,
btrfs_uring_read_extent() doesn't clean up after itself if it returns
-EIOCBQUEUED. Instead, it allocates a priv struct, populates the fields
there that we will need to unlock the inode and free our allocations,
and defers this to the btrfs_uring_read_finished() that gets called when
the bio completes.
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Change btrfs_encoded_read_regular_fill_pages() so that the priv struct
is allocated rather than stored on the stack, in preparation for adding
an asynchronous mode to the function.
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Change btrfs_encoded_read() so that it returns -EAGAIN rather than sleeps
if IOCB_NOWAIT is set in iocb->ki_flags. The conditions that require
sleeping are: inode lock, writeback, extent lock, ordered range.
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Change the behaviour of btrfs_encoded_read() so that if it needs to read
an extent from disk, it leaves the extent and inode locked and returns
-EIOCBQUEUED. The caller is then responsible for doing the I/O via
btrfs_encoded_read_regular() and unlocking the extent and inode.
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
iocb->ki_pos isn't used after this function, so there's no point in
changing its value.
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
After the previous patch, which converted the rb-tree used to track
delayed ref heads into an xarray, the find_ref_head() function is now
used only by one caller which always passes false to the 'return_bigger'
argument. So remove the 'return_bigger' logic, simplifying the function,
and move all the function code to the single caller.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Currently we use a red black tree (rb-tree) to track the delayed ref
heads (in struct btrfs_delayed_ref_root::href_root). This however is not
very efficient when the number of delayed ref heads is large (and it's
very common to be at least in the order of thousands) since rb-trees are
binary trees. For example for 10K delayed ref heads, the tree has a depth
of 13. Besides that, inserting into the tree requires navigating through
it and pulling useless cache lines in the process since the red black tree
nodes are embedded within the delayed ref head structure - on the other
hand, by being embedded, it requires no extra memory allocations.
We can improve this by using an xarray instead which has a much higher
branching factor than a red black tree (binary balanced tree) and is more
cache friendly and behaves like a resizable array, with a much better
search and insertion complexity than a red black tree. This only has one
small disadvantage which is that insertion will sometimes require
allocating memory for the xarray - which may fail (not that often since
it uses a kmem_cache) - but on the other hand we can reduce the delayed
ref head structure size by 24 bytes (from 152 down to 128 bytes) after
removing the embedded red black tree node, meaning than we can now fit
32 delayed ref heads per 4K page instead of 26, and that gain compensates
for the occasional memory allocations needed for the xarray nodes. We
also end up using only 2 cache lines instead of 3 per delayed ref head.
Running the following fs_mark test showed some improvements:
$ cat test.sh
#!/bin/bash
DEV=/dev/nullb0
MNT=/mnt/nullb0
MOUNT_OPTIONS="-o ssd"
FILES=100000
THREADS=$(nproc --all)
echo "performance" | \
tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
mkfs.btrfs -f $DEV
mount $MOUNT_OPTIONS $DEV $MNT
OPTS="-S 0 -L 5 -n $FILES -s 0 -t $THREADS -k"
for ((i = 1; i <= $THREADS; i++)); do
OPTS="$OPTS -d $MNT/d$i"
done
fs_mark $OPTS
umount $MNT
Before this patch:
FSUse% Count Size Files/sec App Overhead
10 1200000 0 171845.7 12253839
16 2400000 0 230898.7 12308254
23 3600000 0 212292.9 12467768
30 4800000 0 195737.8 12627554
46 6000000 0 171055.2 12783329
After this patch:
FSUse% Count Size Files/sec App Overhead
10 1200000 0 173835.0 12246131
16 2400000 0 233537.8 12271746
23 3600000 0 220398.7 12307737
30 4800000 0 204483.6 12392318
40 6000000 0 182923.3 12771843
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Add some comments to struct btrfs_delayed_ref_root's fields to mention
what its spinlock protects.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The delayed refs lock must be held when calling add_delayed_ref_head(),
so assert that it's being held.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The delayed refs lock must be held when calling find_first_ref_head(), so
assert that it's being held.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
We have 3 callers for find_ref_head() so assert at find_ref_head() that we
have the delayed refs lock held, removing the assertion from one of its
callers (btrfs_find_delayed_ref_head()).
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
One of the following patches in the series will need to access fs_info at
btrfs_delete_ref_head(), so pass a fs_info argument to it.
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
One of the following patches in the series will need to access fs_info in
the function find_ref_head(), so pass a fs_info argument to it as well as
to the functions btrfs_select_ref_head() and btrfs_find_delayed_ref_head()
which call find_ref_head().
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The unselect_delayed_ref_head() at extent-tree.c doesn't really belong in
that file as it's a delayed refs specific detail and therefore should be
at delayed-ref.c. Further its inverse, btrfs_select_ref_head(), is at
delayed-ref.c, so it only makes sense to have it there too.
So move unselect_delayed_ref_head() into delayed-ref.c and rename it to
btrfs_unselect_ref_head() so that its name closely matches its inverse
(btrfs_select_ref_head()).
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
