mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-13 22:25:03 +00:00
0b9e66762a
btrfs_can_activate_zone() can be called with the device_list_mutex already
held, which will lead to a deadlock:
insert_dev_extents() // Takes device_list_mutex
`-> insert_dev_extent()
`-> btrfs_insert_empty_item()
`-> btrfs_insert_empty_items()
`-> btrfs_search_slot()
`-> btrfs_cow_block()
`-> __btrfs_cow_block()
`-> btrfs_alloc_tree_block()
`-> btrfs_reserve_extent()
`-> find_free_extent()
`-> find_free_extent_update_loop()
`-> can_allocate_chunk()
`-> btrfs_can_activate_zone() // Takes device_list_mutex again
Instead of using the RCU on fs_devices->device_list we
can use fs_devices->alloc_list, protected by the chunk_mutex to traverse
the list of active devices.
We are in the chunk allocation thread. The newer chunk allocation
happens from the devices in the fs_device->alloc_list protected by the
chunk_mutex.
btrfs_create_chunk()
lockdep_assert_held(&info->chunk_mutex);
gather_device_info
list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list)
Also, a device that reappears after the mount won't join the alloc_list
yet and, it will be in the dev_list, which we don't want to consider in
the context of the chunk alloc.
[15.166572] WARNING: possible recursive locking detected
[15.167117] 5.17.0-rc6-dennis #79 Not tainted
[15.167487] --------------------------------------------
[15.167733] kworker/u8:3/146 is trying to acquire lock:
[15.167733] ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: find_free_extent+0x15a/0x14f0 [btrfs]
[15.167733]
[15.167733] but task is already holding lock:
[15.167733] ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_create_pending_block_groups+0x20a/0x560 [btrfs]
[15.167733]
[15.167733] other info that might help us debug this:
[15.167733] Possible unsafe locking scenario:
[15.167733]
[15.171834] CPU0
[15.171834] ----
[15.171834] lock(&fs_devs->device_list_mutex);
[15.171834] lock(&fs_devs->device_list_mutex);
[15.171834]
[15.171834] *** DEADLOCK ***
[15.171834]
[15.171834] May be due to missing lock nesting notation
[15.171834]
[15.171834] 5 locks held by kworker/u8:3/146:
[15.171834] #0: ffff888100050938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1c3/0x5a0
[15.171834] #1: ffffc9000067be80 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_one_work+0x1c3/0x5a0
[15.176244] #2: ffff88810521e620 (sb_internal){.+.+}-{0:0}, at: flush_space+0x335/0x600 [btrfs]
[15.176244] #3: ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_create_pending_block_groups+0x20a/0x560 [btrfs]
[15.176244] #4: ffff8881152e4b78 (btrfs-dev-00){++++}-{3:3}, at: __btrfs_tree_lock+0x27/0x130 [btrfs]
[15.179641]
[15.179641] stack backtrace:
[15.179641] CPU: 1 PID: 146 Comm: kworker/u8:3 Not tainted 5.17.0-rc6-dennis #79
[15.179641] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1.fc35 04/01/2014
[15.179641] Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs]
[15.179641] Call Trace:
[15.179641] <TASK>
[15.179641] dump_stack_lvl+0x45/0x59
[15.179641] __lock_acquire.cold+0x217/0x2b2
[15.179641] lock_acquire+0xbf/0x2b0
[15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs]
[15.183838] __mutex_lock+0x8e/0x970
[15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs]
[15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs]
[15.183838] ? lock_is_held_type+0xd7/0x130
[15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs]
[15.183838] find_free_extent+0x15a/0x14f0 [btrfs]
[15.183838] ? _raw_spin_unlock+0x24/0x40
[15.183838] ? btrfs_get_alloc_profile+0x106/0x230 [btrfs]
[15.187601] btrfs_reserve_extent+0x131/0x260 [btrfs]
[15.187601] btrfs_alloc_tree_block+0xb5/0x3b0 [btrfs]
[15.187601] __btrfs_cow_block+0x138/0x600 [btrfs]
[15.187601] btrfs_cow_block+0x10f/0x230 [btrfs]
[15.187601] btrfs_search_slot+0x55f/0xbc0 [btrfs]
[15.187601] ? lock_is_held_type+0xd7/0x130
[15.187601] btrfs_insert_empty_items+0x2d/0x60 [btrfs]
[15.187601] btrfs_create_pending_block_groups+0x2b3/0x560 [btrfs]
[15.187601] __btrfs_end_transaction+0x36/0x2a0 [btrfs]
[15.192037] flush_space+0x374/0x600 [btrfs]
[15.192037] ? find_held_lock+0x2b/0x80
[15.192037] ? btrfs_async_reclaim_data_space+0x49/0x180 [btrfs]
[15.192037] ? lock_release+0x131/0x2b0
[15.192037] btrfs_async_reclaim_data_space+0x70/0x180 [btrfs]
[15.192037] process_one_work+0x24c/0x5a0
[15.192037] worker_thread+0x4a/0x3d0
Fixes:
|
||
|---|---|---|
| .. | ||
| 9p | ||
| adfs | ||
| affs | ||
| afs | ||
| autofs | ||
| befs | ||
| bfs | ||
| btrfs | ||
| cachefiles | ||
| ceph | ||
| cifs | ||
| coda | ||
| configfs | ||
| cramfs | ||
| crypto | ||
| debugfs | ||
| devpts | ||
| dlm | ||
| ecryptfs | ||
| efivarfs | ||
| efs | ||
| erofs | ||
| exfat | ||
| exportfs | ||
| ext2 | ||
| ext4 | ||
| f2fs | ||
| fat | ||
| freevxfs | ||
| fscache | ||
| fuse | ||
| gfs2 | ||
| hfs | ||
| hfsplus | ||
| hostfs | ||
| hpfs | ||
| hugetlbfs | ||
| iomap | ||
| isofs | ||
| jbd2 | ||
| jffs2 | ||
| jfs | ||
| kernfs | ||
| ksmbd | ||
| lockd | ||
| minix | ||
| netfs | ||
| nfs | ||
| nfs_common | ||
| nfsd | ||
| nilfs2 | ||
| nls | ||
| notify | ||
| ntfs | ||
| ntfs3 | ||
| ocfs2 | ||
| omfs | ||
| openpromfs | ||
| orangefs | ||
| overlayfs | ||
| proc | ||
| pstore | ||
| qnx4 | ||
| qnx6 | ||
| quota | ||
| ramfs | ||
| reiserfs | ||
| romfs | ||
| smbfs_common | ||
| squashfs | ||
| sysfs | ||
| sysv | ||
| tracefs | ||
| ubifs | ||
| udf | ||
| ufs | ||
| unicode | ||
| vboxsf | ||
| verity | ||
| xfs | ||
| zonefs | ||
| aio.c | ||
| anon_inodes.c | ||
| attr.c | ||
| bad_inode.c | ||
| binfmt_aout.c | ||
| binfmt_elf.c | ||
| binfmt_elf_fdpic.c | ||
| binfmt_flat.c | ||
| binfmt_misc.c | ||
| binfmt_script.c | ||
| buffer.c | ||
| char_dev.c | ||
| compat_binfmt_elf.c | ||
| coredump.c | ||
| d_path.c | ||
| dax.c | ||
| dcache.c | ||
| direct-io.c | ||
| drop_caches.c | ||
| eventfd.c | ||
| eventpoll.c | ||
| exec.c | ||
| fcntl.c | ||
| fhandle.c | ||
| file.c | ||
| file_table.c | ||
| filesystems.c | ||
| fs-writeback.c | ||
| fs_context.c | ||
| fs_parser.c | ||
| fs_pin.c | ||
| fs_struct.c | ||
| fs_types.c | ||
| fsopen.c | ||
| init.c | ||
| inode.c | ||
| internal.h | ||
| io-wq.c | ||
| io-wq.h | ||
| io_uring.c | ||
| ioctl.c | ||
| Kconfig | ||
| Kconfig.binfmt | ||
| kernel_read_file.c | ||
| libfs.c | ||
| locks.c | ||
| Makefile | ||
| mbcache.c | ||
| mount.h | ||
| mpage.c | ||
| namei.c | ||
| namespace.c | ||
| no-block.c | ||
| nsfs.c | ||
| open.c | ||
| pipe.c | ||
| pnode.c | ||
| pnode.h | ||
| posix_acl.c | ||
| proc_namespace.c | ||
| read_write.c | ||
| readdir.c | ||
| remap_range.c | ||
| select.c | ||
| seq_file.c | ||
| signalfd.c | ||
| splice.c | ||
| stack.c | ||
| stat.c | ||
| statfs.c | ||
| super.c | ||
| sync.c | ||
| sysctls.c | ||
| timerfd.c | ||
| userfaultfd.c | ||
| utimes.c | ||
| xattr.c | ||