-----BEGIN PGP SIGNATURE-----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=ze0L
-----END PGP SIGNATURE-----
Merge tag 'for-5.16-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"Several xes and one old ioctl deprecation. Namely there's fix for
crashes/warnings with lzo compression that was suspected to be caused
by first pull merge resolution, but it was a different bug.
Summary:
- regression fix for a crash in lzo due to missing boundary checks of
the page array
- fix crashes on ARM64 due to missing barriers when synchronizing
status bits between work queues
- silence lockdep when reading chunk tree during mount
- fix false positive warning in integrity checker on devices with
disabled write caching
- fix signedness of bitfields in scrub
- start deprecation of balance v1 ioctl"
* tag 'for-5.16-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: deprecate BTRFS_IOC_BALANCE ioctl
btrfs: make 1-bit bit-fields of scrub_page unsigned int
btrfs: check-integrity: fix a warning on write caching disabled disk
btrfs: silence lockdep when reading chunk tree during mount
btrfs: fix memory ordering between normal and ordered work functions
btrfs: fix a out-of-bound access in copy_compressed_data_to_page()
-----BEGIN PGP SIGNATURE-----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=HvYu
-----END PGP SIGNATURE-----
Merge tag 'for-5.16-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs updates from David Sterba:
"The updates this time are more under the hood and enhancing existing
features (subpage with compression and zoned namespaces).
Performance related:
- misc small inode logging improvements (+3% throughput, -11% latency
on sample dbench workload)
- more efficient directory logging: bulk item insertion, less tree
searches and locking
- speed up bulk insertion of items into a b-tree, which is used when
logging directories, when running delayed items for directories
(fsync and transaction commits) and when running the slow path
(full sync) of an fsync (bulk creation run time -4%, deletion -12%)
Core:
- continued subpage support
- make defragmentation work
- make compression write work
- zoned mode
- support ZNS (zoned namespaces), zone capacity is number of
usable blocks in each zone
- add dedicated block group (zoned) for relocation, to prevent
out of order writes in some cases
- greedy block group reclaim, pick the ones with least usable
space first
- preparatory work for send protocol updates
- error handling improvements
- cleanups and refactoring
Fixes:
- lockdep warnings
- in show_devname callback, on seeding device
- device delete on loop device due to conversions to workqueues
- fix deadlock between chunk allocation and chunk btree modifications
- fix tracking of missing device count and status"
* tag 'for-5.16-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (140 commits)
btrfs: remove root argument from check_item_in_log()
btrfs: remove root argument from add_link()
btrfs: remove root argument from btrfs_unlink_inode()
btrfs: remove root argument from drop_one_dir_item()
btrfs: clear MISSING device status bit in btrfs_close_one_device
btrfs: call btrfs_check_rw_degradable only if there is a missing device
btrfs: send: prepare for v2 protocol
btrfs: fix comment about sector sizes supported in 64K systems
btrfs: update device path inode time instead of bd_inode
fs: export an inode_update_time helper
btrfs: fix deadlock when defragging transparent huge pages
btrfs: sysfs: convert scnprintf and snprintf to sysfs_emit
btrfs: make btrfs_super_block size match BTRFS_SUPER_INFO_SIZE
btrfs: update comments for chunk allocation -ENOSPC cases
btrfs: fix deadlock between chunk allocation and chunk btree modifications
btrfs: zoned: use greedy gc for auto reclaim
btrfs: check-integrity: stop storing the block device name in btrfsic_dev_state
btrfs: use btrfs_get_dev_args_from_path in dev removal ioctls
btrfs: add a btrfs_get_dev_args_from_path helper
btrfs: handle device lookup with btrfs_dev_lookup_args
...
Reported bug: https://github.com/kdave/btrfs-progs/issues/389
There's a problem with scrub reporting aborted status but returning
error code 0, on a filesystem with missing and readded device.
Roughly these steps:
- mkfs -d raid1 dev1 dev2
- fill with data
- unmount
- make dev1 disappear
- mount -o degraded
- copy more data
- make dev1 appear again
Running scrub afterwards reports that the command was aborted, but the
system log message says the exit code was 0.
It seems that the cause of the error is decrementing
fs_devices->missing_devices but not clearing device->dev_state. Every
time we umount filesystem, it would call close_ctree, And it would
eventually involve btrfs_close_one_device to close the device, but it
only decrements fs_devices->missing_devices but does not clear the
device BTRFS_DEV_STATE_MISSING bit. Worse, this bug will cause Integer
Overflow, because every time umount, fs_devices->missing_devices will
decrease. If fs_devices->missing_devices value hit 0, it would overflow.
With added debugging:
loop1: detected capacity change from 0 to 20971520
BTRFS: device fsid 56ad51f1-5523-463b-8547-c19486c51ebb devid 1 transid 21 /dev/loop1 scanned by systemd-udevd (2311)
loop2: detected capacity change from 0 to 20971520
BTRFS: device fsid 56ad51f1-5523-463b-8547-c19486c51ebb devid 2 transid 17 /dev/loop2 scanned by systemd-udevd (2313)
BTRFS info (device loop1): flagging fs with big metadata feature
BTRFS info (device loop1): allowing degraded mounts
BTRFS info (device loop1): using free space tree
BTRFS info (device loop1): has skinny extents
BTRFS info (device loop1): before clear_missing.00000000f706684d /dev/loop1 0
BTRFS warning (device loop1): devid 2 uuid 6635ac31-56dd-4852-873b-c60f5e2d53d2 is missing
BTRFS info (device loop1): before clear_missing.0000000000000000 /dev/loop2 1
BTRFS info (device loop1): flagging fs with big metadata feature
BTRFS info (device loop1): allowing degraded mounts
BTRFS info (device loop1): using free space tree
BTRFS info (device loop1): has skinny extents
BTRFS info (device loop1): before clear_missing.00000000f706684d /dev/loop1 0
BTRFS warning (device loop1): devid 2 uuid 6635ac31-56dd-4852-873b-c60f5e2d53d2 is missing
BTRFS info (device loop1): before clear_missing.0000000000000000 /dev/loop2 0
BTRFS info (device loop1): flagging fs with big metadata feature
BTRFS info (device loop1): allowing degraded mounts
BTRFS info (device loop1): using free space tree
BTRFS info (device loop1): has skinny extents
BTRFS info (device loop1): before clear_missing.00000000f706684d /dev/loop1 18446744073709551615
BTRFS warning (device loop1): devid 2 uuid 6635ac31-56dd-4852-873b-c60f5e2d53d2 is missing
BTRFS info (device loop1): before clear_missing.0000000000000000 /dev/loop2 18446744073709551615
If fs_devices->missing_devices is 0, next time it would be 18446744073709551615
After apply this patch, the fs_devices->missing_devices seems to be
right:
$ truncate -s 10g test1
$ truncate -s 10g test2
$ losetup /dev/loop1 test1
$ losetup /dev/loop2 test2
$ mkfs.btrfs -draid1 -mraid1 /dev/loop1 /dev/loop2 -f
$ losetup -d /dev/loop2
$ mount -o degraded /dev/loop1 /mnt/1
$ umount /mnt/1
$ mount -o degraded /dev/loop1 /mnt/1
$ umount /mnt/1
$ mount -o degraded /dev/loop1 /mnt/1
$ umount /mnt/1
$ dmesg
loop1: detected capacity change from 0 to 20971520
loop2: detected capacity change from 0 to 20971520
BTRFS: device fsid 15aa1203-98d3-4a66-bcae-ca82f629c2cd devid 1 transid 5 /dev/loop1 scanned by mkfs.btrfs (1863)
BTRFS: device fsid 15aa1203-98d3-4a66-bcae-ca82f629c2cd devid 2 transid 5 /dev/loop2 scanned by mkfs.btrfs (1863)
BTRFS info (device loop1): flagging fs with big metadata feature
BTRFS info (device loop1): allowing degraded mounts
BTRFS info (device loop1): disk space caching is enabled
BTRFS info (device loop1): has skinny extents
BTRFS info (device loop1): before clear_missing.00000000975bd577 /dev/loop1 0
BTRFS warning (device loop1): devid 2 uuid 8b333791-0b3f-4f57-b449-1c1ab6b51f38 is missing
BTRFS info (device loop1): before clear_missing.0000000000000000 /dev/loop2 1
BTRFS info (device loop1): checking UUID tree
BTRFS info (device loop1): flagging fs with big metadata feature
BTRFS info (device loop1): allowing degraded mounts
BTRFS info (device loop1): disk space caching is enabled
BTRFS info (device loop1): has skinny extents
BTRFS info (device loop1): before clear_missing.00000000975bd577 /dev/loop1 0
BTRFS warning (device loop1): devid 2 uuid 8b333791-0b3f-4f57-b449-1c1ab6b51f38 is missing
BTRFS info (device loop1): before clear_missing.0000000000000000 /dev/loop2 1
BTRFS info (device loop1): flagging fs with big metadata feature
BTRFS info (device loop1): allowing degraded mounts
BTRFS info (device loop1): disk space caching is enabled
BTRFS info (device loop1): has skinny extents
BTRFS info (device loop1): before clear_missing.00000000975bd577 /dev/loop1 0
BTRFS warning (device loop1): devid 2 uuid 8b333791-0b3f-4f57-b449-1c1ab6b51f38 is missing
BTRFS info (device loop1): before clear_missing.0000000000000000 /dev/loop2 1
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Li Zhang <zhanglikernel@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Christoph pointed out that I'm updating bdev->bd_inode for the device
time when we remove block devices from a btrfs file system, however this
isn't actually exposed to anything. The inode we want to update is the
one that's associated with the path to the device, usually on devtmpfs,
so that blkid notices the difference.
We still don't want to do the blkdev_open, so use kern_path() to get the
path to the given device and do the update time on that inode.
Fixes: 8f96a5bfa1 ("btrfs: update the bdev time directly when closing")
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When a task is doing some modification to the chunk btree and it is not in
the context of a chunk allocation or a chunk removal, it can deadlock with
another task that is currently allocating a new data or metadata chunk.
These contexts are the following:
* When relocating a system chunk, when we need to COW the extent buffers
that belong to the chunk btree;
* When adding a new device (ioctl), where we need to add a new device item
to the chunk btree;
* When removing a device (ioctl), where we need to remove a device item
from the chunk btree;
* When resizing a device (ioctl), where we need to update a device item in
the chunk btree and may need to relocate a system chunk that lies beyond
the new device size when shrinking a device.
The problem happens due to a sequence of steps like the following:
1) Task A starts a data or metadata chunk allocation and it locks the
chunk mutex;
2) Task B is relocating a system chunk, and when it needs to COW an extent
buffer of the chunk btree, it has locked both that extent buffer as
well as its parent extent buffer;
3) Since there is not enough available system space, either because none
of the existing system block groups have enough free space or because
the only one with enough free space is in RO mode due to the relocation,
task B triggers a new system chunk allocation. It blocks when trying to
acquire the chunk mutex, currently held by task A;
4) Task A enters btrfs_chunk_alloc_add_chunk_item(), in order to insert
the new chunk item into the chunk btree and update the existing device
items there. But in order to do that, it has to lock the extent buffer
that task B locked at step 2, or its parent extent buffer, but task B
is waiting on the chunk mutex, which is currently locked by task A,
therefore resulting in a deadlock.
One example report when the deadlock happens with system chunk relocation:
INFO: task kworker/u9:5:546 blocked for more than 143 seconds.
Not tainted 5.15.0-rc3+ #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u9:5 state:D stack:25936 pid: 546 ppid: 2 flags:0x00004000
Workqueue: events_unbound btrfs_async_reclaim_metadata_space
Call Trace:
context_switch kernel/sched/core.c:4940 [inline]
__schedule+0xcd9/0x2530 kernel/sched/core.c:6287
schedule+0xd3/0x270 kernel/sched/core.c:6366
rwsem_down_read_slowpath+0x4ee/0x9d0 kernel/locking/rwsem.c:993
__down_read_common kernel/locking/rwsem.c:1214 [inline]
__down_read kernel/locking/rwsem.c:1223 [inline]
down_read_nested+0xe6/0x440 kernel/locking/rwsem.c:1590
__btrfs_tree_read_lock+0x31/0x350 fs/btrfs/locking.c:47
btrfs_tree_read_lock fs/btrfs/locking.c:54 [inline]
btrfs_read_lock_root_node+0x8a/0x320 fs/btrfs/locking.c:191
btrfs_search_slot_get_root fs/btrfs/ctree.c:1623 [inline]
btrfs_search_slot+0x13b4/0x2140 fs/btrfs/ctree.c:1728
btrfs_update_device+0x11f/0x500 fs/btrfs/volumes.c:2794
btrfs_chunk_alloc_add_chunk_item+0x34d/0xea0 fs/btrfs/volumes.c:5504
do_chunk_alloc fs/btrfs/block-group.c:3408 [inline]
btrfs_chunk_alloc+0x84d/0xf50 fs/btrfs/block-group.c:3653
flush_space+0x54e/0xd80 fs/btrfs/space-info.c:670
btrfs_async_reclaim_metadata_space+0x396/0xa90 fs/btrfs/space-info.c:953
process_one_work+0x9df/0x16d0 kernel/workqueue.c:2297
worker_thread+0x90/0xed0 kernel/workqueue.c:2444
kthread+0x3e5/0x4d0 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
INFO: task syz-executor:9107 blocked for more than 143 seconds.
Not tainted 5.15.0-rc3+ #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:23200 pid: 9107 ppid: 7792 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:4940 [inline]
__schedule+0xcd9/0x2530 kernel/sched/core.c:6287
schedule+0xd3/0x270 kernel/sched/core.c:6366
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425
__mutex_lock_common kernel/locking/mutex.c:669 [inline]
__mutex_lock+0xc96/0x1680 kernel/locking/mutex.c:729
btrfs_chunk_alloc+0x31a/0xf50 fs/btrfs/block-group.c:3631
find_free_extent_update_loop fs/btrfs/extent-tree.c:3986 [inline]
find_free_extent+0x25cb/0x3a30 fs/btrfs/extent-tree.c:4335
btrfs_reserve_extent+0x1f1/0x500 fs/btrfs/extent-tree.c:4415
btrfs_alloc_tree_block+0x203/0x1120 fs/btrfs/extent-tree.c:4813
__btrfs_cow_block+0x412/0x1620 fs/btrfs/ctree.c:415
btrfs_cow_block+0x2f6/0x8c0 fs/btrfs/ctree.c:570
btrfs_search_slot+0x1094/0x2140 fs/btrfs/ctree.c:1768
relocate_tree_block fs/btrfs/relocation.c:2694 [inline]
relocate_tree_blocks+0xf73/0x1770 fs/btrfs/relocation.c:2757
relocate_block_group+0x47e/0xc70 fs/btrfs/relocation.c:3673
btrfs_relocate_block_group+0x48a/0xc60 fs/btrfs/relocation.c:4070
btrfs_relocate_chunk+0x96/0x280 fs/btrfs/volumes.c:3181
__btrfs_balance fs/btrfs/volumes.c:3911 [inline]
btrfs_balance+0x1f03/0x3cd0 fs/btrfs/volumes.c:4301
btrfs_ioctl_balance+0x61e/0x800 fs/btrfs/ioctl.c:4137
btrfs_ioctl+0x39ea/0x7b70 fs/btrfs/ioctl.c:4949
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
So fix this by making sure that whenever we try to modify the chunk btree
and we are neither in a chunk allocation context nor in a chunk remove
context, we reserve system space before modifying the chunk btree.
Reported-by: Hao Sun <sunhao.th@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CACkBjsax51i4mu6C0C3vJqQN3NR_iVuucoeG3U1HXjrgzn5FFQ@mail.gmail.com/
Fixes: 79bd37120b ("btrfs: rework chunk allocation to avoid exhaustion of the system chunk array")
CC: stable@vger.kernel.org # 5.14+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For device removal and replace we call btrfs_find_device_by_devspec,
which if we give it a device path and nothing else will call
btrfs_get_dev_args_from_path, which opens the block device and reads the
super block and then looks up our device based on that.
However at this point we're holding the sb write "lock", so reading the
block device pulls in the dependency of ->open_mutex, which produces the
following lockdep splat
======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ #405 Not tainted
------------------------------------------------------
losetup/11576 is trying to acquire lock:
ffff9bbe8cded938 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0
but task is already holding lock:
ffff9bbe88e4fc68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&lo->lo_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
lo_open+0x28/0x60 [loop]
blkdev_get_whole+0x25/0xf0
blkdev_get_by_dev.part.0+0x168/0x3c0
blkdev_open+0xd2/0xe0
do_dentry_open+0x161/0x390
path_openat+0x3cc/0xa20
do_filp_open+0x96/0x120
do_sys_openat2+0x7b/0x130
__x64_sys_openat+0x46/0x70
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #3 (&disk->open_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
blkdev_get_by_dev.part.0+0x56/0x3c0
blkdev_get_by_path+0x98/0xa0
btrfs_get_bdev_and_sb+0x1b/0xb0
btrfs_find_device_by_devspec+0x12b/0x1c0
btrfs_rm_device+0x127/0x610
btrfs_ioctl+0x2a31/0x2e70
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #2 (sb_writers#12){.+.+}-{0:0}:
lo_write_bvec+0xc2/0x240 [loop]
loop_process_work+0x238/0xd00 [loop]
process_one_work+0x26b/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
process_one_work+0x245/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
flush_workqueue+0x91/0x5e0
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of:
(wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&lo->lo_mutex);
lock(&disk->open_mutex);
lock(&lo->lo_mutex);
lock((wq_completion)loop0);
*** DEADLOCK ***
1 lock held by losetup/11576:
#0: ffff9bbe88e4fc68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
stack backtrace:
CPU: 0 PID: 11576 Comm: losetup Not tainted 5.14.0-rc2+ #405
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
dump_stack_lvl+0x57/0x72
check_noncircular+0xcf/0xf0
? stack_trace_save+0x3b/0x50
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
? flush_workqueue+0x67/0x5e0
? lockdep_init_map_type+0x47/0x220
flush_workqueue+0x91/0x5e0
? flush_workqueue+0x67/0x5e0
? verify_cpu+0xf0/0x100
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
? blkdev_ioctl+0x8d/0x2a0
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f31b02404cb
Instead what we want to do is populate our device lookup args before we
grab any locks, and then pass these args into btrfs_rm_device(). From
there we can find the device and do the appropriate removal.
Suggested-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We are going to want to populate our device lookup args outside of any
locks and then do the actual device lookup later, so add a helper to do
this work and make btrfs_find_device_by_devspec() use this helper for
now.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have a lot of device lookup functions that all do something slightly
different. Clean this up by adding a struct to hold the different
lookup criteria, and then pass this around to btrfs_find_device() so it
can do the proper matching based on the lookup criteria.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There's a subtle case where if we're removing the seed device from a
file system we need to free its private copy of the fs_devices. However
we do not need to call close_fs_devices(), because at this point there
are no devices left to close as we've closed the last one. The only
thing that close_fs_devices() does is decrement ->opened, which should
be 1. We want to avoid calling close_fs_devices() here because it has a
lockdep_assert_held(&uuid_mutex), and we are going to stop holding the
uuid_mutex in this path.
So simply decrement the ->opened counter like we should, and then clean
up like normal. Also add a comment explaining what we're doing here as
I initially removed this code erroneously.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For both sprout and seed fsids,
btrfs_fs_devices::num_devices provides device count including missing
btrfs_fs_devices::open_devices provides device count excluding missing
We create a dummy struct btrfs_device for the missing device, so
num_devices != open_devices when there is a missing device.
In btrfs_rm_devices() we wrongly check for %cur_devices->open_devices
before freeing the seed fs_devices. Instead we should check for
%cur_devices->num_devices.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We can grab fs_info reliably from btrfs_raid_bio::bioc, as the bioc is
always passed into alloc_rbio(), and only get released when the raid bio
is released.
Remove btrfs_raid_bio::fs_info member, and cleanup all the @fs_info
parameters for alloc_rbio() callers.
Reviewed-by: Nikolay Borisov <nborisov@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>
Currently btrfs_io_context::fs_info is only initialized in
btrfs_map_bio, but there are call sites like btrfs_map_sblock() which
calls __btrfs_map_block() directly, leaving bioc::fs_info uninitialized
(NULL).
Currently this is fine, but later cleanup will rely on bioc::fs_info to
grab fs_info, and this can be a hidden problem for such usage.
This patch will remove such hidden uninitialized member by always
assigning bioc::fs_info at alloc_btrfs_io_context().
Reviewed-by: Nikolay Borisov <nborisov@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>
We got the following lockdep splat while running fstests (specifically
btrfs/003 and btrfs/020 in a row) with the new rc. This was uncovered
by 87579e9b7d ("loop: use worker per cgroup instead of kworker") which
converted loop to using workqueues, which comes with lockdep
annotations that don't exist with kworkers. The lockdep splat is as
follows:
WARNING: possible circular locking dependency detected
5.14.0-rc2-custom+ #34 Not tainted
------------------------------------------------------
losetup/156417 is trying to acquire lock:
ffff9c7645b02d38 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x84/0x600
but task is already holding lock:
ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #5 (&lo->lo_mutex){+.+.}-{3:3}:
__mutex_lock+0xba/0x7c0
lo_open+0x28/0x60 [loop]
blkdev_get_whole+0x28/0xf0
blkdev_get_by_dev.part.0+0x168/0x3c0
blkdev_open+0xd2/0xe0
do_dentry_open+0x163/0x3a0
path_openat+0x74d/0xa40
do_filp_open+0x9c/0x140
do_sys_openat2+0xb1/0x170
__x64_sys_openat+0x54/0x90
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #4 (&disk->open_mutex){+.+.}-{3:3}:
__mutex_lock+0xba/0x7c0
blkdev_get_by_dev.part.0+0xd1/0x3c0
blkdev_get_by_path+0xc0/0xd0
btrfs_scan_one_device+0x52/0x1f0 [btrfs]
btrfs_control_ioctl+0xac/0x170 [btrfs]
__x64_sys_ioctl+0x83/0xb0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #3 (uuid_mutex){+.+.}-{3:3}:
__mutex_lock+0xba/0x7c0
btrfs_rm_device+0x48/0x6a0 [btrfs]
btrfs_ioctl+0x2d1c/0x3110 [btrfs]
__x64_sys_ioctl+0x83/0xb0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #2 (sb_writers#11){.+.+}-{0:0}:
lo_write_bvec+0x112/0x290 [loop]
loop_process_work+0x25f/0xcb0 [loop]
process_one_work+0x28f/0x5d0
worker_thread+0x55/0x3c0
kthread+0x140/0x170
ret_from_fork+0x22/0x30
-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
process_one_work+0x266/0x5d0
worker_thread+0x55/0x3c0
kthread+0x140/0x170
ret_from_fork+0x22/0x30
-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
__lock_acquire+0x1130/0x1dc0
lock_acquire+0xf5/0x320
flush_workqueue+0xae/0x600
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x650 [loop]
lo_ioctl+0x29d/0x780 [loop]
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x83/0xb0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of:
(wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&lo->lo_mutex);
lock(&disk->open_mutex);
lock(&lo->lo_mutex);
lock((wq_completion)loop0);
*** DEADLOCK ***
1 lock held by losetup/156417:
#0: ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop]
stack backtrace:
CPU: 8 PID: 156417 Comm: losetup Not tainted 5.14.0-rc2-custom+ #34
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Call Trace:
dump_stack_lvl+0x57/0x72
check_noncircular+0x10a/0x120
__lock_acquire+0x1130/0x1dc0
lock_acquire+0xf5/0x320
? flush_workqueue+0x84/0x600
flush_workqueue+0xae/0x600
? flush_workqueue+0x84/0x600
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x650 [loop]
lo_ioctl+0x29d/0x780 [loop]
? __lock_acquire+0x3a0/0x1dc0
? update_dl_rq_load_avg+0x152/0x360
? lock_is_held_type+0xa5/0x120
? find_held_lock.constprop.0+0x2b/0x80
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x83/0xb0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f645884de6b
Usually the uuid_mutex exists to protect the fs_devices that map
together all of the devices that match a specific uuid. In rm_device
we're messing with the uuid of a device, so it makes sense to protect
that here.
However in doing that it pulls in a whole host of lockdep dependencies,
as we call mnt_may_write() on the sb before we grab the uuid_mutex, thus
we end up with the dependency chain under the uuid_mutex being added
under the normal sb write dependency chain, which causes problems with
loop devices.
We don't need the uuid mutex here however. If we call
btrfs_scan_one_device() before we scratch the super block we will find
the fs_devices and not find the device itself and return EBUSY because
the fs_devices is open. If we call it after the scratch happens it will
not appear to be a valid btrfs file system.
We do not need to worry about other fs_devices modifying operations here
because we're protected by the exclusive operations locking.
So drop the uuid_mutex here in order to fix the lockdep splat.
A more detailed explanation from the discussion:
We are worried about rm and scan racing with each other, before this
change we'll zero the device out under the UUID mutex so when scan does
run it'll make sure that it can go through the whole device scan thing
without rm messing with us.
We aren't worried if the scratch happens first, because the result is we
don't think this is a btrfs device and we bail out.
The only case we are concerned with is we scratch _after_ scan is able
to read the superblock and gets a seemingly valid super block, so lets
consider this case.
Scan will call device_list_add() with the device we're removing. We'll
call find_fsid_with_metadata_uuid() and get our fs_devices for this
UUID. At this point we lock the fs_devices->device_list_mutex. This is
what protects us in this case, but we have two cases here.
1. We aren't to the device removal part of the RM. We found our device,
and device name matches our path, we go down and we set total_devices
to our super number of devices, which doesn't affect anything because
we haven't done the remove yet.
2. We are past the device removal part, which is protected by the
device_list_mutex. Scan doesn't find the device, it goes down and
does the
if (fs_devices->opened)
return -EBUSY;
check and we bail out.
Nothing about this situation is ideal, but the lockdep splat is real,
and the fix is safe, tho admittedly a bit scary looking.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ copy more from the discussion ]
Signed-off-by: David Sterba <dsterba@suse.com>
Previously we had "struct btrfs_bio", which records IO context for
mirrored IO and RAID56, and "strcut btrfs_io_bio", which records extra
btrfs specific info for logical bytenr bio.
With "btrfs_bio" renamed to "btrfs_io_context", we are safe to rename
"btrfs_io_bio" to "btrfs_bio" which is a more suitable name now.
The struct btrfs_bio changes meaning by this commit. There was a
suggested name like btrfs_logical_bio but it's a bit long and we'd
prefer to use a shorter name.
This could be a concern for backports to older kernels where the
different meaning could possibly cause confusion or bugs. Comparing the
new and old structures, there's no overlap among the struct members so a
build would break in case of incorrect backport.
We haven't had many backports to bio code anyway so this is more of a
theoretical cause of bugs and a matter of precaution but we'll need to
keep the semantic change in mind.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The structure btrfs_bio is used by two different sites:
- bio->bi_private for mirror based profiles
For those profiles (SINGLE/DUP/RAID1*/RAID10), this structures records
how many mirrors are still pending, and save the original endio
function of the bio.
- RAID56 code
In that case, RAID56 only utilize the stripes info, and no long uses
that to trace the pending mirrors.
So btrfs_bio is not always bind to a bio, and contains more info for IO
context, thus renaming it will make the naming less confusing.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There were few lockdep warnings because btrfs_show_devname() was using
device_list_mutex as recorded in the commits:
0ccd05285e ("btrfs: fix a possible umount deadlock")
779bf3fefa ("btrfs: fix lock dep warning, move scratch dev out of device_list_mutex and uuid_mutex")
And finally, commit 88c14590cd ("btrfs: use RCU in btrfs_show_devname
for device list traversal") removed the device_list_mutex from
btrfs_show_devname for performance reasons.
This patch removes a stale comment about the function
btrfs_show_devname and device_list_mutex.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In preparation to fix a bug in btrfs_show_devname().
Convert fs_devices::latest_bdev type from struct block_device to struct
btrfs_device and, rename the member to fs_devices::latest_dev.
So that btrfs_show_devname() can use fs_devices::latest_dev::name.
Tested-by: Su Yue <l@damenly.su>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_chunk_readonly() checks if the given chunk is writeable. It
returns 1 for readonly, and 0 for writeable. So the return argument type
bool shall suffice instead of the current type int.
Also, rename btrfs_chunk_readonly() to btrfs_chunk_writeable() as we
check if the bg is writeable, and helps to keep the logic at the parent
function simpler to understand.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Update it since commit 944d3f9fac ("btrfs: switch seed device to
list api") did conversion from fs_devices::seed to fs_devices::seed_list.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Su Yue <l@damenly.su>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The user facing function used to allocate new chunks is
btrfs_chunk_alloc, unfortunately there is yet another similar sounding
function - btrfs_alloc_chunk. This creates confusion, especially since
the latter function can be considered "private" in the sense that it
implements the first stage of chunk creation and as such is called by
btrfs_chunk_alloc.
To avoid the awkwardness that comes with having similarly named but
distinctly different in their purpose function rename btrfs_alloc_chunk
to btrfs_create_chunk, given that the main purpose of this function is
to orchestrate the whole process of allocating a chunk - reserving space
into devices, deciding on characteristics of the stripe size and
creating the in-memory structures.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Use sync_blockdev instead of opencoding it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Acked-by: David Sterba <dsterba@suse.com>
Link: https://lore.kernel.org/r/20211019062530.2174626-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When we get an error flushing one device, during a super block commit, we
record the error in the device structure, in the field 'last_flush_error'.
This is used to later check if we should error out the super block commit,
depending on whether the number of flush errors is greater than or equals
to the maximum tolerated device failures for a raid profile.
However if we get a transient device flush error, unmount the filesystem
and later try to mount it, we can fail the mount because we treat that
past error as critical and consider the device is missing. Even if it's
very likely that the error will happen again, as it's probably due to a
hardware related problem, there may be cases where the error might not
happen again. One example is during testing, and a test case like the
new generic/648 from fstests always triggers this. The test cases
generic/019 and generic/475 also trigger this scenario, but very
sporadically.
When this happens we get an error like this:
$ mount /dev/sdc /mnt
mount: /mnt wrong fs type, bad option, bad superblock on /dev/sdc, missing codepage or helper program, or other error.
$ dmesg
(...)
[12918.886926] BTRFS warning (device sdc): chunk 13631488 missing 1 devices, max tolerance is 0 for writable mount
[12918.888293] BTRFS warning (device sdc): writable mount is not allowed due to too many missing devices
[12918.890853] BTRFS error (device sdc): open_ctree failed
The failure happens because when btrfs_check_rw_degradable() is called at
mount time, or at remount from RO to RW time, is sees a non zero value in
a device's ->last_flush_error attribute, and therefore considers that the
device is 'missing'.
Fix this by setting a device's ->last_flush_error to zero when we close a
device, making sure the error is not seen on the next mount attempt. We
only need to track flush errors during the current mount, so that we never
commit a super block if such errors happened.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When removing the device we call blkdev_put() on the device once we've
removed it, and because we have an EXCL open we need to take the
->open_mutex on the block device to clean it up. Unfortunately during
device remove we are holding the sb writers lock, which results in the
following lockdep splat:
======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ #407 Not tainted
------------------------------------------------------
losetup/11595 is trying to acquire lock:
ffff973ac35dd138 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0
but task is already holding lock:
ffff973ac9812c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&lo->lo_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
lo_open+0x28/0x60 [loop]
blkdev_get_whole+0x25/0xf0
blkdev_get_by_dev.part.0+0x168/0x3c0
blkdev_open+0xd2/0xe0
do_dentry_open+0x161/0x390
path_openat+0x3cc/0xa20
do_filp_open+0x96/0x120
do_sys_openat2+0x7b/0x130
__x64_sys_openat+0x46/0x70
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #3 (&disk->open_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
blkdev_put+0x3a/0x220
btrfs_rm_device.cold+0x62/0xe5
btrfs_ioctl+0x2a31/0x2e70
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #2 (sb_writers#12){.+.+}-{0:0}:
lo_write_bvec+0xc2/0x240 [loop]
loop_process_work+0x238/0xd00 [loop]
process_one_work+0x26b/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
process_one_work+0x245/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
flush_workqueue+0x91/0x5e0
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of:
(wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&lo->lo_mutex);
lock(&disk->open_mutex);
lock(&lo->lo_mutex);
lock((wq_completion)loop0);
*** DEADLOCK ***
1 lock held by losetup/11595:
#0: ffff973ac9812c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
stack backtrace:
CPU: 0 PID: 11595 Comm: losetup Not tainted 5.14.0-rc2+ #407
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
dump_stack_lvl+0x57/0x72
check_noncircular+0xcf/0xf0
? stack_trace_save+0x3b/0x50
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
? flush_workqueue+0x67/0x5e0
? lockdep_init_map_type+0x47/0x220
flush_workqueue+0x91/0x5e0
? flush_workqueue+0x67/0x5e0
? verify_cpu+0xf0/0x100
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
? blkdev_ioctl+0x8d/0x2a0
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fc21255d4cb
So instead save the bdev and do the put once we've dropped the sb
writers lock in order to avoid the lockdep recursion.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We update the ctime/mtime of a block device when we remove it so that
blkid knows the device changed. However we do this by re-opening the
block device and calling filp_update_time. This is more correct because
it'll call the inode->i_op->update_time if it exists, but the block dev
inodes do not do this. Instead call generic_update_time() on the
bd_inode in order to avoid the blkdev_open path and get rid of the
following lockdep splat:
======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc2+ #406 Not tainted
------------------------------------------------------
losetup/11596 is trying to acquire lock:
ffff939640d2f538 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0
but task is already holding lock:
ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (&lo->lo_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
lo_open+0x28/0x60 [loop]
blkdev_get_whole+0x25/0xf0
blkdev_get_by_dev.part.0+0x168/0x3c0
blkdev_open+0xd2/0xe0
do_dentry_open+0x161/0x390
path_openat+0x3cc/0xa20
do_filp_open+0x96/0x120
do_sys_openat2+0x7b/0x130
__x64_sys_openat+0x46/0x70
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #3 (&disk->open_mutex){+.+.}-{3:3}:
__mutex_lock+0x7d/0x750
blkdev_get_by_dev.part.0+0x56/0x3c0
blkdev_open+0xd2/0xe0
do_dentry_open+0x161/0x390
path_openat+0x3cc/0xa20
do_filp_open+0x96/0x120
file_open_name+0xc7/0x170
filp_open+0x2c/0x50
btrfs_scratch_superblocks.part.0+0x10f/0x170
btrfs_rm_device.cold+0xe8/0xed
btrfs_ioctl+0x2a31/0x2e70
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #2 (sb_writers#12){.+.+}-{0:0}:
lo_write_bvec+0xc2/0x240 [loop]
loop_process_work+0x238/0xd00 [loop]
process_one_work+0x26b/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
process_one_work+0x245/0x560
worker_thread+0x55/0x3c0
kthread+0x140/0x160
ret_from_fork+0x1f/0x30
-> #0 ((wq_completion)loop0){+.+.}-{0:0}:
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
flush_workqueue+0x91/0x5e0
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
other info that might help us debug this:
Chain exists of:
(wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&lo->lo_mutex);
lock(&disk->open_mutex);
lock(&lo->lo_mutex);
lock((wq_completion)loop0);
*** DEADLOCK ***
1 lock held by losetup/11596:
#0: ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop]
stack backtrace:
CPU: 1 PID: 11596 Comm: losetup Not tainted 5.14.0-rc2+ #406
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
dump_stack_lvl+0x57/0x72
check_noncircular+0xcf/0xf0
? stack_trace_save+0x3b/0x50
__lock_acquire+0x10ea/0x1d90
lock_acquire+0xb5/0x2b0
? flush_workqueue+0x67/0x5e0
? lockdep_init_map_type+0x47/0x220
flush_workqueue+0x91/0x5e0
? flush_workqueue+0x67/0x5e0
? verify_cpu+0xf0/0x100
drain_workqueue+0xa0/0x110
destroy_workqueue+0x36/0x250
__loop_clr_fd+0x9a/0x660 [loop]
? blkdev_ioctl+0x8d/0x2a0
block_ioctl+0x3f/0x50
__x64_sys_ioctl+0x80/0xb0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This crash was observed with a failed assertion on device close:
BTRFS: Transaction aborted (error -28)
WARNING: CPU: 1 PID: 3902 at fs/btrfs/extent-tree.c:2150 btrfs_run_delayed_refs+0x1d2/0x1e0 [btrfs]
Modules linked in: btrfs blake2b_generic libcrc32c crc32c_intel xor zstd_decompress zstd_compress xxhash lzo_compress lzo_decompress raid6_pq loop
CPU: 1 PID: 3902 Comm: kworker/u8:4 Not tainted 5.14.0-rc5-default+ #1532
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014
Workqueue: events_unbound btrfs_async_reclaim_metadata_space [btrfs]
RIP: 0010:btrfs_run_delayed_refs+0x1d2/0x1e0 [btrfs]
RSP: 0018:ffffb7a5452d7d80 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffffabee13c4 RDI: 00000000ffffffff
RBP: ffff97834176a378 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000001 R12: ffff97835195d388
R13: 0000000005b08000 R14: ffff978385484000 R15: 000000000000016c
FS: 0000000000000000(0000) GS:ffff9783bd800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056190d003fe8 CR3: 000000002a81e005 CR4: 0000000000170ea0
Call Trace:
flush_space+0x197/0x2f0 [btrfs]
btrfs_async_reclaim_metadata_space+0x139/0x300 [btrfs]
process_one_work+0x262/0x5e0
worker_thread+0x4c/0x320
? process_one_work+0x5e0/0x5e0
kthread+0x144/0x170
? set_kthread_struct+0x40/0x40
ret_from_fork+0x1f/0x30
irq event stamp: 19334989
hardirqs last enabled at (19334997): [<ffffffffab0e0c87>] console_unlock+0x2b7/0x400
hardirqs last disabled at (19335006): [<ffffffffab0e0d0d>] console_unlock+0x33d/0x400
softirqs last enabled at (19334900): [<ffffffffaba0030d>] __do_softirq+0x30d/0x574
softirqs last disabled at (19334893): [<ffffffffab0721ec>] irq_exit_rcu+0x12c/0x140
---[ end trace 45939e308e0dd3c7 ]---
BTRFS: error (device vdd) in btrfs_run_delayed_refs:2150: errno=-28 No space left
BTRFS info (device vdd): forced readonly
BTRFS warning (device vdd): failed setting block group ro: -30
BTRFS info (device vdd): suspending dev_replace for unmount
assertion failed: !test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state), in fs/btrfs/volumes.c:1150
------------[ cut here ]------------
kernel BUG at fs/btrfs/ctree.h:3431!
invalid opcode: 0000 [#1] PREEMPT SMP
CPU: 1 PID: 3982 Comm: umount Tainted: G W 5.14.0-rc5-default+ #1532
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014
RIP: 0010:assertfail.constprop.0+0x18/0x1a [btrfs]
RSP: 0018:ffffb7a5454c7db8 EFLAGS: 00010246
RAX: 0000000000000068 RBX: ffff978364b91c00 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffffabee13c4 RDI: 00000000ffffffff
RBP: ffff9783523a4c00 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000001 R12: ffff9783523a4d18
R13: 0000000000000000 R14: 0000000000000004 R15: 0000000000000003
FS: 00007f61c8f42800(0000) GS:ffff9783bd800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056190cffa810 CR3: 0000000030b96002 CR4: 0000000000170ea0
Call Trace:
btrfs_close_one_device.cold+0x11/0x55 [btrfs]
close_fs_devices+0x44/0xb0 [btrfs]
btrfs_close_devices+0x48/0x160 [btrfs]
generic_shutdown_super+0x69/0x100
kill_anon_super+0x14/0x30
btrfs_kill_super+0x12/0x20 [btrfs]
deactivate_locked_super+0x2c/0xa0
cleanup_mnt+0x144/0x1b0
task_work_run+0x59/0xa0
exit_to_user_mode_loop+0xe7/0xf0
exit_to_user_mode_prepare+0xaf/0xf0
syscall_exit_to_user_mode+0x19/0x50
do_syscall_64+0x4a/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
This happens when close_ctree is called while a dev_replace hasn't
completed. In close_ctree, we suspend the dev_replace, but keep the
replace target around so that we can resume the dev_replace procedure
when we mount the root again. This is the call trace:
close_ctree():
btrfs_dev_replace_suspend_for_unmount();
btrfs_close_devices():
btrfs_close_fs_devices():
btrfs_close_one_device():
ASSERT(!test_bit(BTRFS_DEV_STATE_REPLACE_TGT,
&device->dev_state));
However, since the replace target sticks around, there is a device
with BTRFS_DEV_STATE_REPLACE_TGT set on close, and we fail the
assertion in btrfs_close_one_device.
To fix this, if we come across the replace target device when
closing, we should properly reset it back to allocation state. This
fix also ensures that if a non-target device has a corrupted state and
has the BTRFS_DEV_STATE_REPLACE_TGT bit set, the assertion will still
catch the error.
Reported-by: David Sterba <dsterba@suse.com>
Fixes: b2a6166768 ("btrfs: fix rw device counting in __btrfs_free_extra_devids")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
It's easy to trigger NULL pointer dereference, just by removing a
non-existing device id:
# mkfs.btrfs -f -m single -d single /dev/test/scratch1 \
/dev/test/scratch2
# mount /dev/test/scratch1 /mnt/btrfs
# btrfs device remove 3 /mnt/btrfs
Then we have the following kernel NULL pointer dereference:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 9 PID: 649 Comm: btrfs Not tainted 5.14.0-rc3-custom+ #35
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:btrfs_rm_device+0x4de/0x6b0 [btrfs]
btrfs_ioctl+0x18bb/0x3190 [btrfs]
? lock_is_held_type+0xa5/0x120
? find_held_lock.constprop.0+0x2b/0x80
? do_user_addr_fault+0x201/0x6a0
? lock_release+0xd2/0x2d0
? __x64_sys_ioctl+0x83/0xb0
__x64_sys_ioctl+0x83/0xb0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
[CAUSE]
Commit a27a94c2b0 ("btrfs: Make btrfs_find_device_by_devspec return
btrfs_device directly") moves the "missing" device path check into
btrfs_rm_device().
But btrfs_rm_device() itself can have case where it only receives
@devid, with NULL as @device_path.
In that case, calling strcmp() on NULL will trigger the NULL pointer
dereference.
Before that commit, we handle the "missing" case inside
btrfs_find_device_by_devspec(), which will not check @device_path at all
if @devid is provided, thus no way to trigger the bug.
[FIX]
Before calling strcmp(), also make sure @device_path is not NULL.
Fixes: a27a94c2b0 ("btrfs: Make btrfs_find_device_by_devspec return btrfs_device directly")
CC: stable@vger.kernel.org # 5.4+
Reported-by: butt3rflyh4ck <butterflyhuangxx@gmail.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's a common practice to start a search using offset (u64)-1, which is
the u64 maximum value, meaning that we want the search_slot function to
be set in the last item with the same objectid and type.
Once we are in this position, it's a matter to start a search backwards
by calling btrfs_previous_item, which will check if we'll need to go to
a previous leaf and other necessary checks, only to be sure that we are
in last offset of the same object and type.
The new btrfs_search_backwards function does the all these steps when
necessary, and can be used to avoid code duplication.
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Function btrfs_check_raid_min_devices() returns error code from the enum
btrfs_err_code and it starts from 1. So there is no need to check if ret
is > 0. So drop this check and also drop the local variable ret.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The data on raid0 and raid10 are supposed to be spread over multiple
devices, so the minimum constraints are set to 2 and 4 respectively.
This is an artificial limit and there's some interest to remove it.
Change this to allow raid0 on one device and raid10 on two devices. This
works as expected eg. when converting or removing devices.
The only difference is when raid0 on two devices gets one device
removed. Unpatched would silently create a single profile, while newly
it would be raid0.
The motivation is to allow to preserve the profile type as long as it
possible for some intermediate state (device removal, conversion), or
when there are disks of different size, with raid0 the otherwise
unusable space of the last device will be used too. Similarly for
raid10, though the two largest devices would need to be the same.
Unpatched kernel will mount and use the degenerate profiles just fine
but won't allow any operation that would not satisfy the stricter device
number constraints, eg. not allowing to go from 3 to 2 devices for
raid10 or various profile conversions.
Example output:
# btrfs fi us -T .
Overall:
Device size: 10.00GiB
Device allocated: 1.01GiB
Device unallocated: 8.99GiB
Device missing: 0.00B
Used: 200.61MiB
Free (estimated): 9.79GiB (min: 9.79GiB)
Free (statfs, df): 9.79GiB
Data ratio: 1.00
Metadata ratio: 1.00
Global reserve: 3.25MiB (used: 0.00B)
Multiple profiles: no
Data Metadata System
Id Path RAID0 single single Unallocated
-- ---------- --------- --------- -------- -----------
1 /dev/sda10 1.00GiB 8.00MiB 1.00MiB 8.99GiB
-- ---------- --------- --------- -------- -----------
Total 1.00GiB 8.00MiB 1.00MiB 8.99GiB
Used 200.25MiB 352.00KiB 16.00KiB
# btrfs dev us .
/dev/sda10, ID: 1
Device size: 10.00GiB
Device slack: 0.00B
Data,RAID0/1: 1.00GiB
Metadata,single: 8.00MiB
System,single: 1.00MiB
Unallocated: 8.99GiB
Note "Data,RAID0/1", with btrfs-progs 5.13+ the number of devices per
profile is printed.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
RAID56 is not only unsafe due to its write-hole problem, but also has
tons of hardcoded PAGE_SIZE.
Disable it for subpage support for now.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Comparators just read the data and thus get const parameters. This
should be also preserved by the local variables, update all comparators
passed to sort or bsearch.
Cleanups:
- unnecessary casts are dropped
- btrfs_cmp_device_free_bytes is cleaned up to follow the common pattern
and 'inline' is dropped as the function address is taken
Signed-off-by: David Sterba <dsterba@suse.com>
There are two helpers doing the same calculations based on nparity and
ncopies. calc_data_stripes can be simplified into one expression, so far
we don't have profile with both copies and parity, so there's no
effective change. calc_stripe_length should reuse the helper and not
repeat the same calculation.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The device allocation is split to two functions, but one just calls the
other and they're very far in the file. Merge them together.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The helper does a simple translation from block group flags to index to
the btrfs_raid_array table. There's no apparent reason to inline the
function, the translation happens usually once per function and is not
called in a loop.
Making it a proper function saves quite some binary code (x86_64,
release config):
text data bss dec hex filename
1164011 19253 14912 1198176 124860 pre/btrfs.ko
1161559 19253 14912 1195724 123ecc post/btrfs.ko
DELTA: -2451
Also add the const attribute as there are no side effects, this could
help compiler to optimize a few things without the function body.
Signed-off-by: David Sterba <dsterba@suse.com>
After calling btrfs_search_slot is a common practice to check if the
slot found isn't bigger than number of slots in the current leaf, and if
so, search for the same key in the next leaf by calling btrfs_next_leaf,
which calls btrfs_next_old_leaf to do the job.
Calling btrfs_next_item in the same situation would end up in the same
code flow, since
* btrfs_next_item
* btrfs_next_old_item
* if slot >= nritems(curr_leaf)
btrfs_next_old_leaf
Change btrfs_verify_dev_extents and calculate_emulated_zone_size
functions to use btrfs_next_leaf in the same situation.
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
One of the final things that must be done to add a new chunk is
inserting its device extent items in the device tree. They describe
the portion of allocated device physical space during phase 1 of
chunk allocation. This is currently done in btrfs_finish_chunk_alloc
whose name isn't very informative. What's more, this function is only
used in block-group.c but is defined as public. There isn't anything
special about it that would warrant it being defined in volumes.c.
Just move btrfs_finish_chunk_alloc and alloc_chunk_dev_extent to
block-group.c, make the former static and rename both functions to
insert_dev_extents and insert_dev_extent respectively.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
-----BEGIN PGP SIGNATURE-----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=J0Pw
-----END PGP SIGNATURE-----
Merge tag 'for-5.14-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- fix -Warray-bounds warning, to help external patchset to make it
default treewide
- fix writeable device accounting (syzbot report)
- fix fsync and log replay after a rename and inode eviction
- fix potentially lost error code when submitting multiple bios for
compressed range
* tag 'for-5.14-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: calculate number of eb pages properly in csum_tree_block
btrfs: fix rw device counting in __btrfs_free_extra_devids
btrfs: fix lost inode on log replay after mix of fsync, rename and inode eviction
btrfs: mark compressed range uptodate only if all bio succeed
When removing a writeable device in __btrfs_free_extra_devids, the rw
device count should be decremented.
This error was caught by Syzbot which reported a warning in
close_fs_devices:
WARNING: CPU: 1 PID: 9355 at fs/btrfs/volumes.c:1168 close_fs_devices+0x763/0x880 fs/btrfs/volumes.c:1168
Modules linked in:
CPU: 0 PID: 9355 Comm: syz-executor552 Not tainted 5.13.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:close_fs_devices+0x763/0x880 fs/btrfs/volumes.c:1168
RSP: 0018:ffffc9000333f2f0 EFLAGS: 00010293
RAX: ffffffff8365f5c3 RBX: 0000000000000001 RCX: ffff888029afd4c0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff88802846f508 R08: ffffffff8365f525 R09: ffffed100337d128
R10: ffffed100337d128 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff888019be8868 R14: 1ffff1100337d10d R15: 1ffff1100337d10a
FS: 00007f6f53828700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000047c410 CR3: 00000000302a6000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
btrfs_close_devices+0xc9/0x450 fs/btrfs/volumes.c:1180
open_ctree+0x8e1/0x3968 fs/btrfs/disk-io.c:3693
btrfs_fill_super fs/btrfs/super.c:1382 [inline]
btrfs_mount_root+0xac5/0xc60 fs/btrfs/super.c:1749
legacy_get_tree+0xea/0x180 fs/fs_context.c:592
vfs_get_tree+0x86/0x270 fs/super.c:1498
fc_mount fs/namespace.c:993 [inline]
vfs_kern_mount+0xc9/0x160 fs/namespace.c:1023
btrfs_mount+0x3d3/0xb50 fs/btrfs/super.c:1809
legacy_get_tree+0xea/0x180 fs/fs_context.c:592
vfs_get_tree+0x86/0x270 fs/super.c:1498
do_new_mount fs/namespace.c:2905 [inline]
path_mount+0x196f/0x2be0 fs/namespace.c:3235
do_mount fs/namespace.c:3248 [inline]
__do_sys_mount fs/namespace.c:3456 [inline]
__se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433
do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae
Because fs_devices->rw_devices was not 0 after
closing all devices. Here is the call trace that was observed:
btrfs_mount_root():
btrfs_scan_one_device():
device_list_add(); <---------------- device added
btrfs_open_devices():
open_fs_devices():
btrfs_open_one_device(); <-------- writable device opened,
rw device count ++
btrfs_fill_super():
open_ctree():
btrfs_free_extra_devids():
__btrfs_free_extra_devids(); <--- writable device removed,
rw device count not decremented
fail_tree_roots:
btrfs_close_devices():
close_fs_devices(); <------- rw device count off by 1
As a note, prior to commit cf89af146b ("btrfs: dev-replace: fail
mount if we don't have replace item with target device"), rw_devices
was decremented on removing a writable device in
__btrfs_free_extra_devids only if the BTRFS_DEV_STATE_REPLACE_TGT bit
was not set for the device. However, this check does not need to be
reinstated as it is now redundant and incorrect.
In __btrfs_free_extra_devids, we skip removing the device if it is the
target for replacement. This is done by checking whether device->devid
== BTRFS_DEV_REPLACE_DEVID. Since BTRFS_DEV_STATE_REPLACE_TGT is set
only on the device with devid BTRFS_DEV_REPLACE_DEVID, no devices
should have the BTRFS_DEV_STATE_REPLACE_TGT bit set after the check,
and so it's redundant to test for that bit.
Additionally, following commit 82372bc816 ("Btrfs: make
the logic of source device removing more clear"), rw_devices is
incremented whenever a writeable device is added to the alloc
list (including the target device in btrfs_dev_replace_finishing), so
all removals of writable devices from the alloc list should also be
accompanied by a decrement to rw_devices.
Reported-by: syzbot+a70e2ad0879f160b9217@syzkaller.appspotmail.com
Fixes: cf89af146b ("btrfs: dev-replace: fail mount if we don't have replace item with target device")
CC: stable@vger.kernel.org # 5.10+
Tested-by: syzbot+a70e2ad0879f160b9217@syzkaller.appspotmail.com
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
-----BEGIN PGP SIGNATURE-----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=v00S
-----END PGP SIGNATURE-----
Merge tag 'for-5.14-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs zoned mode fixes from David Sterba:
- fix deadlock when allocating system chunk
- fix wrong mutex unlock on an error path
- fix extent map splitting for append operation
- update and fix message reporting unusable chunk space
- don't block when background zone reclaim runs with balance in
parallel
* tag 'for-5.14-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: zoned: fix wrong mutex unlock on failure to allocate log root tree
btrfs: don't block if we can't acquire the reclaim lock
btrfs: properly split extent_map for REQ_OP_ZONE_APPEND
btrfs: rework chunk allocation to avoid exhaustion of the system chunk array
btrfs: fix deadlock with concurrent chunk allocations involving system chunks
btrfs: zoned: print unusable percentage when reclaiming block groups
btrfs: zoned: fix types for u64 division in btrfs_reclaim_bgs_work
Commit eafa4fd0ad ("btrfs: fix exhaustion of the system chunk array
due to concurrent allocations") fixed a problem that resulted in
exhausting the system chunk array in the superblock when there are many
tasks allocating chunks in parallel. Basically too many tasks enter the
first phase of chunk allocation without previous tasks having finished
their second phase of allocation, resulting in too many system chunks
being allocated. That was originally observed when running the fallocate
tests of stress-ng on a PowerPC machine, using a node size of 64K.
However that commit also introduced a deadlock where a task in phase 1 of
the chunk allocation waited for another task that had allocated a system
chunk to finish its phase 2, but that other task was waiting on an extent
buffer lock held by the first task, therefore resulting in both tasks not
making any progress. That change was later reverted by a patch with the
subject "btrfs: fix deadlock with concurrent chunk allocations involving
system chunks", since there is no simple and short solution to address it
and the deadlock is relatively easy to trigger on zoned filesystems, while
the system chunk array exhaustion is not so common.
This change reworks the chunk allocation to avoid the system chunk array
exhaustion. It accomplishes that by making the first phase of chunk
allocation do the updates of the device items in the chunk btree and the
insertion of the new chunk item in the chunk btree. This is done while
under the protection of the chunk mutex (fs_info->chunk_mutex), in the
same critical section that checks for available system space, allocates
a new system chunk if needed and reserves system chunk space. This way
we do not have chunk space reserved until the second phase completes.
The same logic is applied to chunk removal as well, since it keeps
reserved system space long after it is done updating the chunk btree.
For direct allocation of system chunks, the previous behaviour remains,
because otherwise we would deadlock on extent buffers of the chunk btree.
Changes to the chunk btree are by large done by chunk allocation and chunk
removal, which first reserve chunk system space and then later do changes
to the chunk btree. The other remaining cases are uncommon and correspond
to adding a device, removing a device and resizing a device. All these
other cases do not pre-reserve system space, they modify the chunk btree
right away, so they don't hold reserved space for a long period like chunk
allocation and chunk removal do.
The diff of this change is huge, but more than half of it is just addition
of comments describing both how things work regarding chunk allocation and
removal, including both the new behavior and the parts of the old behavior
that did not change.
CC: stable@vger.kernel.org # 5.12+
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Tested-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Tested-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Relocation and send do not play well together because while send is
running a block group can be relocated, a transaction committed and
the respective disk extents get re-allocated and written to or discarded
while send is about to do something with the extents.
This was explained in commit 9e967495e0 ("Btrfs: prevent send failures
and crashes due to concurrent relocation"), which prevented balance and
send from running in parallel but it did not address one remaining case
where chunk relocation can happen: shrinking a device (and device deletion
which shrinks a device's size to 0 before deleting the device).
We also have now one more case where relocation is triggered: on zoned
filesystems partially used block groups get relocated by a background
thread, introduced in commit 18bb8bbf13 ("btrfs: zoned: automatically
reclaim zones").
So make sure that instead of preventing balance from running when there
are ongoing send operations, we prevent relocation from happening.
This uses the infrastructure recently added by a patch that has the
subject: "btrfs: add cancellable chunk relocation support".
Also it adds a spinlock used exclusively for the exclusivity between
send and relocation, as before fs_info->balance_mutex was used, which
would make an attempt to run send to block waiting for balance to
finish, which can take a lot of time on large filesystems.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The parameter @len is not really used in btrfs_bio_fits_in_stripe(),
just remove it.
It got removed in 4203431319 ("btrfs: let callers of
btrfs_get_io_geometry pass the em"), before that btrfs_get_chunk_map
utilized it.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit b2598edf8b ("btrfs: remove unused argument seed from
btrfs_find_device") removed the argument seed from btrfs_find_device
but forgot the comment, so remove it.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Su Yue <l@damenly.su>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Linus Torvalds