linux/fs/btrfs
Filipe Manana f55985f4dd Btrfs: scrub, fix sleep in atomic context
My previous patch "Btrfs: fix scrub race leading to use-after-free"
introduced the possibility to sleep in an atomic context, which happens
when the scrub_lock mutex is held at the time scrub_pending_bio_dec()
is called - this function can be called under an atomic context.
Chris ran into this in a debug kernel which gave the following trace:

[ 1928.950319] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:621
[ 1928.967334] in_atomic(): 1, irqs_disabled(): 0, pid: 149670, name: fsstress
[ 1928.981324] INFO: lockdep is turned off.
[ 1928.989244] CPU: 24 PID: 149670 Comm: fsstress Tainted: G        W     3.19.0-rc7-mason+ #41
[ 1929.006418] Hardware name: ZTSYSTEMS Echo Ridge T4  /A9DRPF-10D, BIOS 1.07 05/10/2012
[ 1929.022207]  ffffffff81a22cf8 ffff881076e03b78 ffffffff816b8dd9 ffff881076e03b78
[ 1929.037267]  ffff880d8e828710 ffff881076e03ba8 ffffffff810856c4 ffff881076e03bc8
[ 1929.052315]  0000000000000000 000000000000026d ffffffff81a22cf8 ffff881076e03bd8
[ 1929.067381] Call Trace:
[ 1929.072344]  <IRQ>  [<ffffffff816b8dd9>] dump_stack+0x4f/0x6e
[ 1929.083968]  [<ffffffff810856c4>] ___might_sleep+0x174/0x230
[ 1929.095352]  [<ffffffff810857d2>] __might_sleep+0x52/0x90
[ 1929.106223]  [<ffffffff816bb68f>] mutex_lock_nested+0x2f/0x3b0
[ 1929.117951]  [<ffffffff810ab37d>] ? trace_hardirqs_on+0xd/0x10
[ 1929.129708]  [<ffffffffa05dc838>] scrub_pending_bio_dec+0x38/0x70 [btrfs]
[ 1929.143370]  [<ffffffffa05dd0e0>] scrub_parity_bio_endio+0x50/0x70 [btrfs]
[ 1929.157191]  [<ffffffff812fa603>] bio_endio+0x53/0xa0
[ 1929.167382]  [<ffffffffa05f96bc>] rbio_orig_end_io+0x7c/0xa0 [btrfs]
[ 1929.180161]  [<ffffffffa05f97ba>] raid_write_parity_end_io+0x5a/0x80 [btrfs]
[ 1929.194318]  [<ffffffff812fa603>] bio_endio+0x53/0xa0
[ 1929.204496]  [<ffffffff8130401b>] blk_update_request+0x1eb/0x450
[ 1929.216569]  [<ffffffff81096e58>] ? trigger_load_balance+0x78/0x500
[ 1929.229176]  [<ffffffff8144c74d>] scsi_end_request+0x3d/0x1f0
[ 1929.240740]  [<ffffffff8144ccac>] scsi_io_completion+0xac/0x5b0
[ 1929.252654]  [<ffffffff81441c50>] scsi_finish_command+0xf0/0x150
[ 1929.264725]  [<ffffffff8144d317>] scsi_softirq_done+0x147/0x170
[ 1929.276635]  [<ffffffff8130ace6>] blk_done_softirq+0x86/0xa0
[ 1929.288014]  [<ffffffff8105d92e>] __do_softirq+0xde/0x600
[ 1929.298885]  [<ffffffff8105df6d>] irq_exit+0xbd/0xd0
(...)

Fix this by using a reference count on the scrub context structure
instead of locking the scrub_lock mutex.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-02-14 08:19:14 -08:00
..
tests btrfs: switch extent_state state to unsigned 2015-01-21 18:02:04 -08:00
acl.c btrfs: remove useless ACL check 2014-06-09 17:20:42 -07:00
async-thread.c btrfs: remove unlikely from NULL checks 2014-10-02 16:06:19 +02:00
async-thread.h Btrfs: implement repair function when direct read fails 2014-09-17 13:39:01 -07:00
backref.c btrfs: cleanup, remove inode_ref_info helper 2015-01-14 19:23:47 +01:00
backref.h btrfs: cleanup, remove inode_item_info helper 2015-01-14 19:23:47 +01:00
btrfs_inode.h Btrfs: Add code to support file creation time 2015-02-02 18:39:16 -08:00
check-integrity.c Btrfs: include vmalloc.h in check-integrity.c 2014-11-25 06:01:11 -08:00
check-integrity.h block: submit_bio_wait() conversions 2013-11-24 16:33:41 -07:00
compression.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2014-12-12 11:15:23 -08:00
compression.h btrfs: zero out left over bytes after processing compression streams 2014-11-30 09:33:51 -08:00
ctree.c Btrfs: insert_new_root: Fix lock type of the extent buffer. 2015-01-22 05:42:23 -08:00
ctree.h Btrfs: fix race between transaction commit and empty block group removal 2015-02-02 19:24:48 -08:00
delayed-inode.c Btrfs: Add code to support file creation time 2015-02-02 18:39:16 -08:00
delayed-inode.h Btrfs: introduce the delayed inode ref deletion for the single link inode 2014-01-28 13:20:09 -08:00
delayed-ref.c Btrfs: rework qgroup accounting 2014-06-09 17:20:48 -07:00
delayed-ref.h Btrfs: rework qgroup accounting 2014-06-09 17:20:48 -07:00
dev-replace.c Btrfs: btrfs_rm_dev_replace_blocked(): Use wait_event() 2015-01-21 18:06:48 -08:00
dev-replace.h
dir-item.c Btrfs: make xattr replace operations atomic 2014-11-20 17:20:07 -08:00
disk-io.c Btrfs: fix race between transaction commit and empty block group removal 2015-02-02 19:24:48 -08:00
disk-io.h btrfs: sink blocksize parameter to btrfs_find_create_tree_block 2014-12-12 18:07:21 +01:00
export.c btrfs: kill the key type accessor helpers 2014-09-17 13:37:12 -07:00
export.h
extent_io.c btrfs: clear bio reference after submit_one_bio() 2015-02-02 19:24:51 -08:00
extent_io.h btrfs: switch extent_state state to unsigned 2015-01-21 18:02:04 -08:00
extent_map.c Btrfs: do not move em to modified list when unpinning 2014-11-21 11:59:54 -08:00
extent_map.h Btrfs: fix NULL pointer crash when running balance and scrub concurrently 2014-06-19 14:20:55 -07:00
extent-tree.c btrfs: delete chunk allocation attemp when setting block group ro 2015-02-02 19:25:20 -08:00
file-item.c Btrfs: fix kfree on list_head in btrfs_lookup_csums_range error cleanup 2014-11-04 06:59:04 -08:00
file.c Btrfs: fix snapshot inconsistency after a file write followed by truncate 2014-11-25 07:41:23 -08:00
free-space-cache.c btrfs: cleanup init for list in free-space-cache 2015-02-02 19:25:50 -08:00
free-space-cache.h Btrfs: fix race between writing free space cache and trimming 2014-12-02 18:35:09 -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: fix fsync log replay for inodes with a mix of regular refs and extrefs 2015-01-21 18:02:05 -08:00
inode-map.c Btrfs: fix race between writing free space cache and trimming 2014-12-02 18:35:09 -08:00
inode-map.h
inode.c Btrfs: Add code to support file creation time 2015-02-02 18:39:16 -08:00
ioctl.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2014-12-12 11:15:23 -08:00
Kconfig Btrfs: fix btrfs boot when compiled as built-in 2014-01-28 13:20:31 -08:00
locking.c btrfs: fix lockups from btrfs_clear_path_blocking 2014-11-19 10:34:35 -08:00
locking.h btrfs: fix lockups from btrfs_clear_path_blocking 2014-11-19 10:34:35 -08:00
lzo.c btrfs: zero out left over bytes after processing compression streams 2014-11-30 09:33:51 -08:00
Makefile Btrfs: add sanity tests for new qgroup accounting code 2014-06-09 17:20:49 -07:00
math.h
ordered-data.c Btrfs: collect only the necessary ordered extents on ranged fsync 2014-11-21 11:59:56 -08:00
ordered-data.h Btrfs: collect only the necessary ordered extents on ranged fsync 2014-11-21 11:59:56 -08:00
orphan.c btrfs: kill the key type accessor helpers 2014-09-17 13:37:12 -07:00
print-tree.c btrfs: remove parameter blocksize from read_tree_block 2014-10-02 17:14:50 +02:00
print-tree.h
props.c Btrfs: add support for inode properties 2014-01-28 13:20:24 -08:00
props.h Btrfs: add support for inode properties 2014-01-28 13:20:24 -08:00
qgroup.c btrfs: qgroup: move WARN_ON() to the correct location. 2015-01-21 18:22:37 -08:00
qgroup.h btrfs: qgroup: account shared subtrees during snapshot delete 2014-08-15 07:43:14 -07:00
raid56.c Btrfs: Include map_type in raid_bio 2015-01-21 18:06:49 -08:00
raid56.h Btrfs: Make raid_map array be inlined in btrfs_bio structure 2015-01-21 18:06:47 -08:00
rcu-string.h
reada.c Btrfs: add ref_count and free function for btrfs_bio 2015-01-21 18:06:48 -08:00
relocation.c btrfs: sink blocksize parameter to tree_block_processed 2014-12-12 18:07:22 +01:00
root-tree.c Btrfs: use bitfield instead of integer data type for the some variants in btrfs_root 2014-06-09 17:20:40 -07:00
scrub.c Btrfs: scrub, fix sleep in atomic context 2015-02-14 08:19:14 -08:00
send.c btrfs: kill btrfs_inode_*time helpers 2015-02-02 18:39:07 -08:00
send.h
struct-funcs.c
super.c btrfs: remove a no-op unfreeze superbock callback 2015-01-21 18:02:04 -08:00
sysfs.c Btrfs: add missing cleanup on sysfs init failure 2015-02-02 19:24:49 -08:00
sysfs.h btrfs: code optimize: BTRFS_ATTR_RW could set the mode 2014-09-17 13:37:59 -07:00
transaction.c Btrfs: track dirty block groups on their own list 2015-01-21 17:36:52 -08:00
transaction.h Btrfs: track dirty block groups on their own list 2015-01-21 17:36:52 -08:00
tree-defrag.c Btrfs: use bitfield instead of integer data type for the some variants in btrfs_root 2014-06-09 17:20:40 -07:00
tree-log.c Btrfs: fix scheduler warning when syncing log 2015-02-14 08:19:14 -08:00
tree-log.h Btrfs: fix data corruption after fast fsync and writeback error 2014-09-19 06:57:51 -07:00
ulist.c Btrfs: do not export ulist functions 2014-01-29 07:06:27 -08:00
ulist.h Btrfs: Fix memory corruption by ulist_add_merge() on 32bit arch 2014-08-15 07:43:19 -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: add more checks to btrfs_read_sys_array 2015-02-02 19:24:39 -08:00
volumes.h Btrfs: Include map_type in raid_bio 2015-01-21 18:06:49 -08:00
xattr.c Btrfs: make xattr replace operations atomic 2014-11-20 17:20:07 -08:00
xattr.h btrfs: use generic posix ACL infrastructure 2014-01-25 23:58:18 -05:00
zlib.c btrfs: zero out left over bytes after processing compression streams 2014-11-30 09:33:51 -08:00