Anand Jain 779bf3fefa btrfs: fix lock dep warning, move scratch dev out of device_list_mutex and uuid_mutex ... When the replace target fails, the target device will be taken out of fs device list, scratch + update_dev_time and freed. However we could do the scratch + update_dev_time and free part after the device has been taken out of device list, so that we don't have to hold the device_list_mutex and uuid_mutex locks. Reported issue: [ 5375.718845] ====================================================== [ 5375.718846] [ INFO: possible circular locking dependency detected ] [ 5375.718849] 4.4.5-scst31x-debug-11+ #40 Not tainted [ 5375.718849] ------------------------------------------------------- [ 5375.718851] btrfs-health/4662 is trying to acquire lock: [ 5375.718861] (sb_writers){.+.+.+}, at: [<ffffffff812214f7>] __sb_start_write+0xb7/0xf0 [ 5375.718862] [ 5375.718862] but task is already holding lock: [ 5375.718907] (&fs_devs->device_list_mutex){+.+.+.}, at: [<ffffffffa028263c>] btrfs_destroy_dev_replace_tgtdev+0x3c/0x150 [btrfs] [ 5375.718907] [ 5375.718907] which lock already depends on the new lock. [ 5375.718907] [ 5375.718908] [ 5375.718908] the existing dependency chain (in reverse order) is: [ 5375.718911] [ 5375.718911] -> #3 (&fs_devs->device_list_mutex){+.+.+.}: [ 5375.718917] [<ffffffff810da4be>] lock_acquire+0xce/0x1e0 [ 5375.718921] [<ffffffff81633949>] mutex_lock_nested+0x69/0x3c0 [ 5375.718940] [<ffffffffa0219bf6>] btrfs_show_devname+0x36/0x210 [btrfs] [ 5375.718945] [<ffffffff81267079>] show_vfsmnt+0x49/0x150 [ 5375.718948] [<ffffffff81240b07>] m_show+0x17/0x20 [ 5375.718951] [<ffffffff81246868>] seq_read+0x2d8/0x3b0 [ 5375.718955] [<ffffffff8121df28>] __vfs_read+0x28/0xd0 [ 5375.718959] [<ffffffff8121e806>] vfs_read+0x86/0x130 [ 5375.718962] [<ffffffff8121f4c9>] SyS_read+0x49/0xa0 [ 5375.718966] [<ffffffff81637976>] entry_SYSCALL_64_fastpath+0x16/0x7a [ 5375.718968] [ 5375.718968] -> #2 (namespace_sem){+++++.}: [ 5375.718971] [<ffffffff810da4be>] lock_acquire+0xce/0x1e0 [ 5375.718974] [<ffffffff81635199>] down_write+0x49/0x80 [ 5375.718977] [<ffffffff81243593>] lock_mount+0x43/0x1c0 [ 5375.718979] [<ffffffff81243c13>] do_add_mount+0x23/0xd0 [ 5375.718982] [<ffffffff81244afb>] do_mount+0x27b/0xe30 [ 5375.718985] [<ffffffff812459dc>] SyS_mount+0x8c/0xd0 [ 5375.718988] [<ffffffff81637976>] entry_SYSCALL_64_fastpath+0x16/0x7a [ 5375.718991] [ 5375.718991] -> #1 (&sb->s_type->i_mutex_key#5){+.+.+.}: [ 5375.718994] [<ffffffff810da4be>] lock_acquire+0xce/0x1e0 [ 5375.718996] [<ffffffff81633949>] mutex_lock_nested+0x69/0x3c0 [ 5375.719001] [<ffffffff8122d608>] path_openat+0x468/0x1360 [ 5375.719004] [<ffffffff8122f86e>] do_filp_open+0x7e/0xe0 [ 5375.719007] [<ffffffff8121da7b>] do_sys_open+0x12b/0x210 [ 5375.719010] [<ffffffff8121db7e>] SyS_open+0x1e/0x20 [ 5375.719013] [<ffffffff81637976>] entry_SYSCALL_64_fastpath+0x16/0x7a [ 5375.719015] [ 5375.719015] -> #0 (sb_writers){.+.+.+}: [ 5375.719018] [<ffffffff810d97ca>] __lock_acquire+0x17ba/0x1ae0 [ 5375.719021] [<ffffffff810da4be>] lock_acquire+0xce/0x1e0 [ 5375.719026] [<ffffffff810d3bef>] percpu_down_read+0x4f/0xa0 [ 5375.719028] [<ffffffff812214f7>] __sb_start_write+0xb7/0xf0 [ 5375.719031] [<ffffffff81242eb4>] mnt_want_write+0x24/0x50 [ 5375.719035] [<ffffffff8122ded2>] path_openat+0xd32/0x1360 [ 5375.719037] [<ffffffff8122f86e>] do_filp_open+0x7e/0xe0 [ 5375.719040] [<ffffffff8121d8a4>] file_open_name+0xe4/0x130 [ 5375.719043] [<ffffffff8121d923>] filp_open+0x33/0x60 [ 5375.719073] [<ffffffffa02776a6>] update_dev_time+0x16/0x40 [btrfs] [ 5375.719099] [<ffffffffa02825be>] btrfs_scratch_superblocks+0x4e/0x90 [btrfs] [ 5375.719123] [<ffffffffa0282665>] btrfs_destroy_dev_replace_tgtdev+0x65/0x150 [btrfs] [ 5375.719150] [<ffffffffa02c6c80>] btrfs_dev_replace_finishing+0x6b0/0x990 [btrfs] [ 5375.719175] [<ffffffffa02c729e>] btrfs_dev_replace_start+0x33e/0x540 [btrfs] [ 5375.719199] [<ffffffffa02c7f58>] btrfs_auto_replace_start+0xf8/0x140 [btrfs] [ 5375.719222] [<ffffffffa02464e6>] health_kthread+0x246/0x490 [btrfs] [ 5375.719225] [<ffffffff810a70df>] kthread+0xef/0x110 [ 5375.719229] [<ffffffff81637d2f>] ret_from_fork+0x3f/0x70 [ 5375.719230] [ 5375.719230] other info that might help us debug this: [ 5375.719230] [ 5375.719233] Chain exists of: [ 5375.719233] sb_writers --> namespace_sem --> &fs_devs->device_list_mutex [ 5375.719233] [ 5375.719234] Possible unsafe locking scenario: [ 5375.719234] [ 5375.719234] CPU0 CPU1 [ 5375.719235] ---- ---- [ 5375.719236] lock(&fs_devs->device_list_mutex); [ 5375.719238] lock(namespace_sem); [ 5375.719239] lock(&fs_devs->device_list_mutex); [ 5375.719241] lock(sb_writers); [ 5375.719241] [ 5375.719241] *** DEADLOCK *** [ 5375.719241] [ 5375.719243] 4 locks held by btrfs-health/4662: [ 5375.719266] #0: (&fs_info->health_mutex){+.+.+.}, at: [<ffffffffa0246303>] health_kthread+0x63/0x490 [btrfs] [ 5375.719293] #1: (&fs_info->dev_replace.lock_finishing_cancel_unmount){+.+.+.}, at: [<ffffffffa02c6611>] btrfs_dev_replace_finishing+0x41/0x990 [btrfs] [ 5375.719319] #2: (uuid_mutex){+.+.+.}, at: [<ffffffffa0282620>] btrfs_destroy_dev_replace_tgtdev+0x20/0x150 [btrfs] [ 5375.719343] #3: (&fs_devs->device_list_mutex){+.+.+.}, at: [<ffffffffa028263c>] btrfs_destroy_dev_replace_tgtdev+0x3c/0x150 [btrfs] [ 5375.719343] [ 5375.719343] stack backtrace: [ 5375.719347] CPU: 2 PID: 4662 Comm: btrfs-health Not tainted 4.4.5-scst31x-debug-11+ #40 [ 5375.719348] Hardware name: Supermicro SYS-6018R-WTRT/X10DRW-iT, BIOS 1.0c 01/07/2015 [ 5375.719352] 0000000000000000 ffff880856f73880 ffffffff813529e3 ffffffff826182a0 [ 5375.719354] ffffffff8260c090 ffff880856f738c0 ffffffff810d667c ffff880856f73930 [ 5375.719357] ffff880861f32b40 ffff880861f32b68 0000000000000003 0000000000000004 [ 5375.719357] Call Trace: [ 5375.719363] [<ffffffff813529e3>] dump_stack+0x85/0xc2 [ 5375.719366] [<ffffffff810d667c>] print_circular_bug+0x1ec/0x260 [ 5375.719369] [<ffffffff810d97ca>] __lock_acquire+0x17ba/0x1ae0 [ 5375.719373] [<ffffffff810f606d>] ? debug_lockdep_rcu_enabled+0x1d/0x20 [ 5375.719376] [<ffffffff810da4be>] lock_acquire+0xce/0x1e0 [ 5375.719378] [<ffffffff812214f7>] ? __sb_start_write+0xb7/0xf0 [ 5375.719383] [<ffffffff810d3bef>] percpu_down_read+0x4f/0xa0 [ 5375.719385] [<ffffffff812214f7>] ? __sb_start_write+0xb7/0xf0 [ 5375.719387] [<ffffffff812214f7>] __sb_start_write+0xb7/0xf0 [ 5375.719389] [<ffffffff81242eb4>] mnt_want_write+0x24/0x50 [ 5375.719393] [<ffffffff8122ded2>] path_openat+0xd32/0x1360 [ 5375.719415] [<ffffffffa02462a0>] ? btrfs_congested_fn+0x180/0x180 [btrfs] [ 5375.719418] [<ffffffff810f606d>] ? debug_lockdep_rcu_enabled+0x1d/0x20 [ 5375.719420] [<ffffffff8122f86e>] do_filp_open+0x7e/0xe0 [ 5375.719423] [<ffffffff810f615d>] ? rcu_read_lock_sched_held+0x6d/0x80 [ 5375.719426] [<ffffffff81201a9b>] ? kmem_cache_alloc+0x26b/0x5d0 [ 5375.719430] [<ffffffff8122e7d4>] ? getname_kernel+0x34/0x120 [ 5375.719433] [<ffffffff8121d8a4>] file_open_name+0xe4/0x130 [ 5375.719436] [<ffffffff8121d923>] filp_open+0x33/0x60 [ 5375.719462] [<ffffffffa02776a6>] update_dev_time+0x16/0x40 [btrfs] [ 5375.719485] [<ffffffffa02825be>] btrfs_scratch_superblocks+0x4e/0x90 [btrfs] [ 5375.719506] [<ffffffffa0282665>] btrfs_destroy_dev_replace_tgtdev+0x65/0x150 [btrfs] [ 5375.719530] [<ffffffffa02c6c80>] btrfs_dev_replace_finishing+0x6b0/0x990 [btrfs] [ 5375.719554] [<ffffffffa02c6b23>] ? btrfs_dev_replace_finishing+0x553/0x990 [btrfs] [ 5375.719576] [<ffffffffa02c729e>] btrfs_dev_replace_start+0x33e/0x540 [btrfs] [ 5375.719598] [<ffffffffa02c7f58>] btrfs_auto_replace_start+0xf8/0x140 [btrfs] [ 5375.719621] [<ffffffffa02464e6>] health_kthread+0x246/0x490 [btrfs] [ 5375.719641] [<ffffffffa02463d8>] ? health_kthread+0x138/0x490 [btrfs] [ 5375.719661] [<ffffffffa02462a0>] ? btrfs_congested_fn+0x180/0x180 [btrfs] [ 5375.719663] [<ffffffff810a70df>] kthread+0xef/0x110 [ 5375.719666] [<ffffffff810a6ff0>] ? kthread_create_on_node+0x200/0x200 [ 5375.719669] [<ffffffff81637d2f>] ret_from_fork+0x3f/0x70 [ 5375.719672] [<ffffffff810a6ff0>] ? kthread_create_on_node+0x200/0x200 [ 5375.719697] ------------[ cut here ]------------ Signed-off-by: Anand Jain <anand.jain@oracle.com> Reported-by: Yauhen Kharuzhy <yauhen.kharuzhy@zavadatar.com> Signed-off-by: David Sterba <dsterba@suse.com>		2016-05-06 15:22:49 +02:00
..
tests	mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage	2016-04-04 10:41:08 -07:00
acl.c	Merge branch 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs	2016-01-18 12:44:40 -08:00
async-thread.c	btrfs: async-thread: Fix a use-after-free error for trace	2016-01-25 16:50:26 -08:00
async-thread.h	btrfs: async_thread: Fix workqueue 'max_active' value when initializing	2015-08-31 11:46:40 -07:00
backref.c	Merge branch 'cleanups-4.6' into for-chris-4.6	2016-02-26 15:38:33 +01:00
backref.h	btrfs: cleanup, remove inode_item_info helper	2015-01-14 19:23:47 +01:00
btrfs_inode.h	btrfs: put delayed item hook into inode	2016-01-07 14:26:58 +01:00
check-integrity.c	mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage	2016-04-04 10:41:08 -07:00
check-integrity.h	block: submit_bio_wait() conversions	2013-11-24 16:33:41 -07:00
compression.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
compression.h	btrfs: move btrfs_compression_type to compression.h	2016-03-11 17:12:46 +01:00
ctree.c	btrfs: fallback to vmalloc in btrfs_compare_tree	2016-04-04 16:29:22 +02:00
ctree.h	btrfs: bugfix: handle FS_IOC32_{GETFLAGS,SETFLAGS,GETVERSION} in btrfs_ioctl	2016-04-28 10:40:27 +02:00
delayed-inode.c	btrfs: Print Warning only if ENOSPC_DEBUG is enabled	2016-03-14 14:59:54 +01:00
delayed-inode.h	btrfs: properly set the termination value of ctx->pos in readdir	2016-02-11 07:01:59 -08:00
delayed-ref.c	btrfs: drop null testing before destroy functions	2016-02-18 11:46:03 +01:00
delayed-ref.h	btrfs: better packing of btrfs_delayed_extent_op	2016-01-07 14:26:58 +01:00
dev-replace.c	btrfs: Reset IO error counters before start of device replacing	2016-04-04 16:29:22 +02:00
dev-replace.h	Btrfs: fix lockdep deadlock warning due to dev_replace	2016-02-23 13:10:10 +01:00
dir-item.c	Btrfs: make xattr replace operations atomic	2014-11-20 17:20:07 -08:00
disk-io.c	Merge branch 'PAGE_CACHE_SIZE-removal'	2016-04-04 10:50:24 -07:00
disk-io.h	Merge branch 'misc-cleanups-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5	2016-01-11 06:08:37 -08:00
export.c	BTRFS: support NFSv2 export	2015-10-06 06:55:23 -07:00
export.h
extent-tree.c	Merge branch 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs	2016-04-09 10:41:34 -07:00
extent_io.c	Btrfs: cleanup error handling in extent_write_cached_pages	2016-04-28 10:41:47 +02:00
extent_io.h	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
extent_map.c	btrfs: Fix misspellings in comments.	2016-03-14 15:05:02 +01:00
extent_map.h	btrfs: cleanup, stop casting for extent_map->lookup everywhere	2016-01-15 19:22:28 +01:00
file-item.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
file.c	Btrfs: __btrfs_buffered_write: Pass valid file offset when releasing delalloc space	2016-04-28 10:41:47 +02:00
free-space-cache.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
free-space-cache.h	btrfs: constify remaining structs with function pointers	2016-01-07 15:01:14 +01:00
free-space-tree.c	Revert "btrfs: synchronize incompat feature bits with sysfs files"	2016-01-29 08:19:37 -08:00
free-space-tree.h	Btrfs: implement the free space B-tree	2015-12-17 12:16:47 -08:00
hash.c	btrfs: LLVMLinux: Remove VLAIS	2014-10-14 10:51:22 +02:00
hash.h	Btrfs: fix btrfs boot when compiled as built-in	2014-01-28 13:20:31 -08:00
inode-item.c	Btrfs: consolidate btrfs_error() to btrfs_std_error()	2015-09-29 16:30:00 +02:00
inode-map.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
inode-map.h	Btrfs: Initialize btrfs_root->highest_objectid when loading tree root and subvolume roots	2016-01-15 19:25:02 +01:00
inode.c	btrfs: bugfix: handle FS_IOC32_{GETFLAGS,SETFLAGS,GETVERSION} in btrfs_ioctl	2016-04-28 10:40:27 +02:00
ioctl.c	btrfs: bugfix: handle FS_IOC32_{GETFLAGS,SETFLAGS,GETVERSION} in btrfs_ioctl	2016-04-28 10:40:27 +02:00
Kconfig	rcu: Make SRCU optional by using CONFIG_SRCU	2015-01-06 11:04:29 -08:00
locking.c	btrfs: cleanup, remove stray return statements	2016-01-07 14:30:52 +01:00
locking.h	btrfs: fix lockups from btrfs_clear_path_blocking	2014-11-19 10:34:35 -08:00
lzo.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
Makefile	Btrfs: add free space tree sanity tests	2015-12-17 12:16:47 -08:00
math.h	btrfs: cleanup 64bit/32bit divs, compile time constants	2015-03-03 17:23:57 +01:00
ordered-data.c	btrfs: Fix misspellings in comments.	2016-03-14 15:05:02 +01:00
ordered-data.h	Btrfs: change how we wait for pending ordered extents	2015-10-21 18:51:40 -07:00
orphan.c	btrfs: kill the key type accessor helpers	2014-09-17 13:37:12 -07:00
print-tree.c	btrfs: teach print_leaf about temporary item subtypes	2016-02-11 16:15:43 +01:00
print-tree.h	btrfs: make static code static & remove dead code	2013-05-06 15:55:23 -04:00
props.c	btrfs: move btrfs_compression_type to compression.h	2016-03-11 17:12:46 +01:00
props.h	Btrfs: add support for inode properties	2014-01-28 13:20:24 -08:00
qgroup.c	btrfs: Add qgroup tracing	2016-04-04 16:29:22 +02:00
qgroup.h	btrfs: qgroup: Check if qgroup reserved space leaked	2015-10-21 18:41:10 -07:00
raid56.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
raid56.h	Btrfs: add RAID 5/6 BTRFS_RBIO_REBUILD_MISSING operation	2015-08-09 07:34:26 -07:00
rcu-string.h
reada.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
relocation.c	Merge branch 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs	2016-04-09 10:41:34 -07:00
root-tree.c	Merge branch 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs	2016-03-21 18:12:42 -07:00
scrub.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
send.c	btrfs: send: silence an integer overflow warning	2016-05-06 15:22:49 +02:00
send.h	Btrfs: use linux/sizes.h to represent constants	2016-01-07 14:38:02 +01:00
struct-funcs.c	mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage	2016-04-04 10:41:08 -07:00
super.c	btrfs: avoid overflowing f_bfree	2016-05-06 15:22:49 +02:00
sysfs.c	btrfs: sysfs: check initialization state before updating features	2016-01-27 05:40:10 -08:00
sysfs.h	btrfs: sysfs: introduce helper for syncing bits with sysfs files	2016-01-21 18:50:40 +01:00
transaction.c	Merge branch 'cleanups-4.6' into for-chris-4.6	2016-02-26 15:38:33 +01:00
transaction.h	btrfs: preallocate path for snapshot creation at ioctl time	2016-01-07 15:20:55 +01:00
tree-defrag.c	Btrfs: fix locking bugs when defragging leaves	2015-12-18 02:51:32 +00:00
tree-log.c	Btrfs: fix file/data loss caused by fsync after rename and new inode	2016-04-06 17:01:44 -07:00
tree-log.h	Btrfs: fix unreplayable log after snapshot delete + parent dir fsync	2016-03-01 08:23:25 -08:00
ulist.c	btrfs: ulist: Add ulist_del() function.	2015-06-10 09:26:17 -07:00
ulist.h	btrfs: ulist: Add ulist_del() function.	2015-06-10 09:26:17 -07:00
uuid-tree.c	Btrfs: make btrfs_search_forward return with nodes unlocked	2014-09-17 13:38:02 -07:00
volumes.c	btrfs: fix lock dep warning, move scratch dev out of device_list_mutex and uuid_mutex	2016-05-06 15:22:49 +02:00
volumes.h	Merge branch 'misc-cleanups-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5	2016-01-11 06:08:37 -08:00
xattr.c	Btrfs: fix listxattrs not listing all xattrs packed in the same item	2016-03-01 08:23:41 -08:00
xattr.h	btrfs: Use xattr handler infrastructure	2015-12-06 21:34:14 -05:00
zlib.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00