linux/fs/afs
Linus Torvalds fad70111d5 afs fixes
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Merge tag 'afs-fixes-20201016' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull afs updates from David Howells:
 "A collection of fixes to fix afs_cell struct refcounting, thereby
  fixing a slew of related syzbot bugs:

   - Fix the cell tree in the netns to use an rwsem rather than RCU.

     There seem to be some problems deriving from the use of RCU and a
     seqlock to walk the rbtree, but it's not entirely clear what since
     there are several different failures being seen.

     Changing things to use an rwsem instead makes it more robust. The
     extra performance derived from using RCU isn't necessary in this
     case since the only time we're looking up a cell is during mount or
     when cells are being manually added.

   - Fix the refcounting by splitting the usage counter into a memory
     refcount and an active users counter. The usage counter was doing
     double duty, keeping track of whether a cell is still in use and
     keeping track of when it needs to be destroyed - but this makes the
     clean up tricky. Separating these out simplifies the logic.

   - Fix purging a cell that has an alias. A cell alias pins the cell
     it's an alias of, but the alias is always later in the list. Trying
     to purge in a single pass causes rmmod to hang in such a case.

   - Fix cell removal. If a cell's manager is requeued whilst it's
     removing itself, the manager will run again and re-remove itself,
     causing problems in various places. Follow Hillf Danton's
     suggestion to insert a more terminal state that causes the manager
     to do nothing post-removal.

  In additional to the above, two other changes:

   - Add a tracepoint for the cell refcount and active users count. This
     helped with debugging the above and may be useful again in future.

   - Downgrade an assertion to a print when a still-active server is
     seen during purging. This was happening as a consequence of
     incomplete cell removal before the servers were cleaned up"

* tag 'afs-fixes-20201016' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Don't assert on unpurgeable server records
  afs: Add tracing for cell refcount and active user count
  afs: Fix cell removal
  afs: Fix cell purging with aliases
  afs: Fix cell refcounting by splitting the usage counter
  afs: Fix rapid cell addition/removal by not using RCU on cells tree
2020-10-16 15:22:41 -07:00
..
addr_list.c afs: Use kfree_rcu() instead of casting kfree() to rcu_callback_t 2020-03-13 10:47:33 -07:00
afs_cm.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
afs_fs.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
afs_vl.h afs: Implement client support for the YFSVL.GetCellName RPC op 2020-06-04 15:37:57 +01:00
afs.h afs: Implement client support for the YFSVL.GetCellName RPC op 2020-06-04 15:37:57 +01:00
cache.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
callback.c afs: Fix the by-UUID server tree to allow servers with the same UUID 2020-06-04 15:37:57 +01:00
cell.c afs: Add tracing for cell refcount and active user count 2020-10-16 14:39:21 +01:00
cmservice.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
dir_edit.c afs: Remove set but not used variables 'before', 'after' 2019-11-21 20:36:00 +00:00
dir_silly.c afs: Fix silly rename 2020-06-16 22:00:28 +01:00
dir.c treewide: Remove uninitialized_var() usage 2020-07-16 12:35:15 -07:00
dynroot.c afs: Add tracing for cell refcount and active user count 2020-10-16 14:39:21 +01:00
file.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
flock.c afs: Remove erroneous fallthough annotation 2020-08-27 14:33:01 -05:00
fs_operation.c afs: Fix key ref leak in afs_put_operation() 2020-08-20 10:41:45 -07:00
fs_probe.c rxrpc: Make rxrpc_kernel_get_srtt() indicate validity 2020-08-20 18:21:28 +01:00
fsclient.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
inode.c afs: Fix deadlock between writeback and truncate 2020-10-08 10:50:55 -07:00
internal.h afs: Add tracing for cell refcount and active user count 2020-10-16 14:39:21 +01:00
Kconfig docs: filesystems: fix renamed references 2020-04-20 15:45:22 -06:00
main.c afs: Fix rapid cell addition/removal by not using RCU on cells tree 2020-10-16 14:04:59 +01:00
Makefile afs: Detect cell aliases 1 - Cells with root volumes 2020-06-04 15:37:57 +01:00
misc.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
mntpt.c afs: Add tracing for cell refcount and active user count 2020-10-16 14:39:21 +01:00
proc.c afs: Add tracing for cell refcount and active user count 2020-10-16 14:39:21 +01:00
protocol_uae.h afs: Add support for the UAE error table 2019-06-28 18:37:53 +01:00
protocol_yfs.h afs: Implement client support for the YFSVL.GetCellName RPC op 2020-06-04 15:37:57 +01:00
rotate.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
rxrpc.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
security.c treewide: Remove uninitialized_var() usage 2020-07-16 12:35:15 -07:00
server_list.c afs: Reorganise volume and server trees to be rooted on the cell 2020-06-04 15:37:57 +01:00
server.c afs: Don't assert on unpurgeable server records 2020-10-16 14:39:34 +01:00
super.c afs fixes 2020-10-16 15:22:41 -07:00
vl_alias.c afs: Add tracing for cell refcount and active user count 2020-10-16 14:39:21 +01:00
vl_list.c afs: Don't use VL probe running state to make decisions outside probe code 2020-08-20 18:21:28 +01:00
vl_probe.c afs: Don't use VL probe running state to make decisions outside probe code 2020-08-20 18:21:28 +01:00
vl_rotate.c afs: Add tracing for cell refcount and active user count 2020-10-16 14:39:21 +01:00
vlclient.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
volume.c afs: Add tracing for cell refcount and active user count 2020-10-16 14:39:21 +01:00
write.c afs: Fix deadlock between writeback and truncate 2020-10-08 10:50:55 -07:00
xattr.c afs: Build an abstraction around an "operation" concept 2020-06-04 15:37:17 +01:00
xdr_fs.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
yfsclient.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00