remarkable-linux/fs/btrfs
Ilya Dryomov 964fb15acf Btrfs: eliminate races in worker stopping code
The current implementation of worker threads in Btrfs has races in
worker stopping code, which cause all kinds of panics and lockups when
running btrfs/011 xfstest in a loop.  The problem is that
btrfs_stop_workers is unsynchronized with respect to check_idle_worker,
check_busy_worker and __btrfs_start_workers.

E.g., check_idle_worker race flow:

       btrfs_stop_workers():            check_idle_worker(aworker):
- grabs the lock
- splices the idle list into the
  working list
- removes the first worker from the
  working list
- releases the lock to wait for
  its kthread's completion
                                  - grabs the lock
                                  - if aworker is on the working list,
                                    moves aworker from the working list
                                    to the idle list
                                  - releases the lock
- grabs the lock
- puts the worker
- removes the second worker from the
  working list
                              ......
        btrfs_stop_workers returns, aworker is on the idle list
                 FS is umounted, memory is freed
                              ......
              aworker is waken up, fireworks ensue

With this applied, I wasn't able to trigger the problem in 48 hours,
whereas previously I could reliably reproduce at least one of these
races within an hour.

Reported-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-10-04 16:02:13 -04:00
..
tests Btrfs: separate out tests into their own directory 2013-09-01 08:15:38 -04:00
acl.c Btrfs: skip adding an acl attribute if we don't have to 2012-12-16 20:46:15 -05:00
async-thread.c Btrfs: eliminate races in worker stopping code 2013-10-04 16:02:13 -04:00
async-thread.h Btrfs: eliminate races in worker stopping code 2013-10-04 16:02:13 -04:00
backref.c Btrfs: allocate prelim_ref with a slab allocater 2013-09-01 08:16:27 -04:00
backref.h Btrfs: allocate prelim_ref with a slab allocater 2013-09-01 08:16:27 -04:00
btrfs_inode.h Btrfs: check roots last log commit when checking if an inode has been logged 2013-09-21 11:05:24 -04:00
check-integrity.c Btrfs: Use %z to format size_t 2013-09-01 08:16:19 -04:00
check-integrity.h Btrfs: add optional integrity check code 2011-12-21 19:14:09 +01:00
compat.h Btrfs: drop remaining LINUX_KERNEL_VERSION checks and compat code 2009-01-06 09:38:55 -05:00
compression.c Btrfs: Remove superfluous casts from u64 to unsigned long long 2013-09-01 08:16:08 -04:00
compression.h btrfs: make static code static & remove dead code 2013-05-06 15:55:23 -04:00
ctree.c Btrfs: fixup error handling in btrfs_reloc_cow 2013-09-21 10:58:54 -04:00
ctree.h Btrfs: remove space_info->reservation_progress 2013-09-21 11:05:27 -04:00
delayed-inode.c Btrfs: fix printing of non NULL terminated string 2013-09-01 08:16:20 -04:00
delayed-inode.h [readdir] convert btrfs 2013-06-29 12:57:00 +04:00
delayed-ref.c Btrfs: get rid of sparse warnings 2013-09-01 08:15:50 -04:00
delayed-ref.h Btrfs: handle running extent ops with skinny metadata 2013-05-17 21:40:15 -04:00
dev-replace.c Btrfs: kill delay_iput arg to the wait_ordered functions 2013-09-21 11:05:27 -04:00
dev-replace.h Btrfs: add new sources for device replace code 2012-12-12 17:15:41 -05:00
dir-item.c btrfs: make static code static & remove dead code 2013-05-06 15:55:23 -04:00
disk-io.c Btrfs: add the missing mutex unlock in write_all_supers() 2013-09-21 11:05:28 -04:00
disk-io.h Btrfs: introduce grab/put functions for the root of the fs/file tree 2013-06-14 11:29:38 -04:00
export.c Btrfs: cleanup: don't check the same thing twice 2013-06-14 11:29:30 -04:00
export.h NFS support for btrfs - v3 2008-09-25 11:04:06 -04:00
extent-tree.c Btrfs: remove space_info->reservation_progress 2013-09-21 11:05:27 -04:00
extent_io.c Btrfs: fix crash of compressed writes 2013-10-04 16:02:11 -04:00
extent_io.h btrfs: mark some local function as 'static' 2013-09-01 08:15:51 -04:00
extent_map.c btrfs: make static code static & remove dead code 2013-05-06 15:55:23 -04:00
extent_map.h Btrfs: fix bad extent logging 2013-05-06 15:54:34 -04:00
file-item.c Btrfs: Remove superfluous casts from u64 to unsigned long long 2013-09-01 08:16:08 -04:00
file.c Btrfs: don't leak transaction in btrfs_sync_file() 2013-09-21 11:05:29 -04:00
free-space-cache.c Btrfs: allocate the free space by the existed max extent size when ENOSPC 2013-09-21 11:05:23 -04:00
free-space-cache.h Btrfs: allocate the free space by the existed max extent size when ENOSPC 2013-09-21 11:05:23 -04:00
hash.h btrfs: extended inode refs 2012-10-09 09:14:45 -04:00
inode-item.c btrfs: make static code static & remove dead code 2013-05-06 15:55:23 -04:00
inode-map.c Btrfs: don't use global block reservation for inode cache truncation 2013-05-17 21:40:22 -04:00
inode-map.h Btrfs: Support reading/writing on disk free ino cache 2011-04-25 16:46:11 +08:00
inode.c Btrfs: dir_inode_operations should use btrfs_update_time also 2013-09-21 11:05:30 -04:00
ioctl.c btrfs: change extent-same to copy entire argument struct 2013-09-21 11:05:31 -04:00
Kconfig Btrfs: add support for asserts 2013-09-01 08:16:32 -04:00
locking.c btrfs: make static code static & remove dead code 2013-05-06 15:55:23 -04:00
locking.h Btrfs: remove btrfs_try_spin_lock 2013-03-14 14:57:10 -04:00
lzo.c Btrfs: return -1 when lzo compression makes data bigger 2013-09-01 07:57:19 -04:00
Makefile Btrfs: introduce a tree for items that map UUIDs to something 2013-09-01 08:15:52 -04:00
math.h Btrfs: cleanup duplicated division functions 2012-12-11 13:31:30 -05:00
ordered-data.c Btrfs: kill delay_iput arg to the wait_ordered functions 2013-09-21 11:05:27 -04:00
ordered-data.h Btrfs: kill delay_iput arg to the wait_ordered functions 2013-09-21 11:05:27 -04:00
orphan.c btrfs: replace many BUG_ONs with proper error handling 2012-03-22 11:52:54 +01:00
print-tree.c Btrfs: Remove superfluous casts from u64 to unsigned long long 2013-09-01 08:16:08 -04:00
print-tree.h btrfs: make static code static & remove dead code 2013-05-06 15:55:23 -04:00
qgroup.c Btrfs: Remove superfluous casts from u64 to unsigned long long 2013-09-01 08:16:08 -04:00
raid56.c Btrfs, raid56: fix memory leak when allocating pages for p/q stripes failed 2013-09-01 08:04:27 -04:00
raid56.h Btrfs: RAID5 and RAID6 2013-02-01 14:24:23 -05:00
rcu-string.h Btrfs: use rcu to protect device->name 2012-06-14 21:29:16 -04:00
reada.c Btrfs: fix reada debug code compilation 2013-05-06 15:54:55 -04:00
relocation.c Btrfs: kill delay_iput arg to the wait_ordered functions 2013-09-21 11:05:27 -04:00
root-tree.c Btrfs: Remove superfluous casts from u64 to unsigned long long 2013-09-01 08:16:08 -04:00
scrub.c Btrfs: improve replacing nocow extents 2013-09-21 11:05:26 -04:00
send.c btrfs: reuse kbasename helper 2013-09-01 08:16:36 -04:00
send.h btrfs: make static code static & remove dead code 2013-05-06 15:55:23 -04:00
struct-funcs.c Btrfs: rewrite BTRFS_SETGET_FUNCS 2012-07-23 16:28:06 -04:00
super.c Btrfs: create the uuid tree on remount rw 2013-09-21 11:50:43 -04:00
sysfs.c btrfs: fixup/remove module.h usage as required 2013-03-01 15:01:01 -05:00
transaction.c Btrfs: fix transid verify errors when recovering log tree 2013-10-04 16:02:09 -04:00
transaction.h btrfs: mark some local function as 'static' 2013-09-01 08:15:51 -04:00
tree-defrag.c btrfs: remove cache only arguments from defrag path 2013-02-20 12:59:36 -05:00
tree-log.c Btrfs: drop dir i_size when adding new names on replay 2013-09-21 11:05:25 -04:00
tree-log.h btrfs: make static code static & remove dead code 2013-05-06 15:55:23 -04:00
ulist.c Btrfs: fix crash regarding to ulist_add_merge 2013-07-02 11:50:59 -04:00
ulist.h Btrfs: add a rb_tree to improve performance of ulist search 2013-05-06 15:54:44 -04:00
uuid-tree.c Btrfs: check UUID tree during mount if required 2013-09-01 08:15:58 -04:00
volumes.c btrfs: Add btrfs: prefix to kernel log output 2013-09-21 11:05:30 -04:00
volumes.h Btrfs: add btrfs_alloc_device and switch to it 2013-09-01 08:16:04 -04:00
xattr.c btrfs: make static code static & remove dead code 2013-05-06 15:55:23 -04:00
xattr.h fs/vfs/security: pass last path component to LSM on inode creation 2011-02-01 11:12:29 -05:00
zlib.c btrfs: fix message printing 2012-10-09 09:19:57 -04:00