linux-toradex.git/fs/ocfs2, branch v4.4.20

ocfs2: fix posix_acl_create deadlock

2016-05-19T00:06:44+00:00

commit c25a1e0671fbca7b2c0d0757d533bd2650d6dc0c upstream.

Commit 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure")
refactored code to use posix_acl_create.  The problem with this function
is that it is not mindful of the cluster wide inode lock making it
unsuitable for use with ocfs2 inode creation with ACLs.  For example,
when used in ocfs2_mknod, this function can cause deadlock as follows.
The parent dir inode lock is taken when calling posix_acl_create ->
get_acl -> ocfs2_iop_get_acl which takes the inode lock again.  This can
cause deadlock if there is a blocked remote lock request waiting for the
lock to be downconverted.  And same deadlock happened in ocfs2_reflink.
This fix is to revert back using ocfs2_init_acl.

Fixes: 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure")
Signed-off-by: Tariq Saeed 
Signed-off-by: Junxiao Bi 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Joseph Qi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ocfs2: revert using ocfs2_acl_chmod to avoid inode cluster lock hang

2016-05-19T00:06:43+00:00

commit 5ee0fbd50fdf1c1329de8bee35ea9d7c6a81a2e0 upstream.

Commit 743b5f1434f5 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()")
introduced this issue.  ocfs2_setattr called by chmod command holds
cluster wide inode lock when calling posix_acl_chmod.  This latter
function in turn calls ocfs2_iop_get_acl and ocfs2_iop_set_acl.  These
two are also called directly from vfs layer for getfacl/setfacl commands
and therefore acquire the cluster wide inode lock.  If a remote
conversion request comes after the first inode lock in ocfs2_setattr,
OCFS2_LOCK_BLOCKED will be set.  And this will cause the second call to
inode lock from the ocfs2_iop_get_acl() to block indefinetly.

The deleted version of ocfs2_acl_chmod() calls __posix_acl_chmod() which
does not call back into the filesystem.  Therefore, we restore
ocfs2_acl_chmod(), modify it slightly for locking as needed, and use that
instead.

Fixes: 743b5f1434f5 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()")
Signed-off-by: Tariq Saeed 
Signed-off-by: Junxiao Bi 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Joseph Qi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ocfs2/dlm: fix BUG in dlm_move_lockres_to_recovery_list

2016-04-12T16:09:04+00:00

commit be12b299a83fc807bbaccd2bcb8ec50cbb0cb55c upstream.

When master handles convert request, it queues ast first and then
returns status.  This may happen that the ast is sent before the request
status because the above two messages are sent by two threads.  And
right after the ast is sent, if master down, it may trigger BUG in
dlm_move_lockres_to_recovery_list in the requested node because ast
handler moves it to grant list without clear lock->convert_pending.  So
remove BUG_ON statement and check if the ast is processed in
dlmconvert_remote.

Signed-off-by: Joseph Qi 
Reported-by: Yiwen Jiang 
Cc: Junxiao Bi 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Tariq Saeed 
Cc: Junxiao Bi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ocfs2/dlm: fix race between convert and recovery

2016-04-12T16:09:04+00:00

commit ac7cf246dfdbec3d8fed296c7bf30e16f5099dac upstream.

There is a race window between dlmconvert_remote and
dlm_move_lockres_to_recovery_list, which will cause a lock with
OCFS2_LOCK_BUSY in grant list, thus system hangs.

dlmconvert_remote
{
        spin_lock(&res->spinlock);
        list_move_tail(&lock->list, &res->converting);
        lock->convert_pending = 1;
        spin_unlock(&res->spinlock);

        status = dlm_send_remote_convert_request();
        >>>>>> race window, master has queued ast and return DLM_NORMAL,
               and then down before sending ast.
               this node detects master down and calls
               dlm_move_lockres_to_recovery_list, which will revert the
               lock to grant list.
               Then OCFS2_LOCK_BUSY won't be cleared as new master won't
               send ast any more because it thinks already be authorized.

        spin_lock(&res->spinlock);
        lock->convert_pending = 0;
        if (status != DLM_NORMAL)
                dlm_revert_pending_convert(res, lock);
        spin_unlock(&res->spinlock);
}

In this case, check if res->state has DLM_LOCK_RES_RECOVERING bit set
(res is still in recovering) or res master changed (new master has
finished recovery), reset the status to DLM_RECOVERING, then it will
retry convert.

Signed-off-by: Joseph Qi 
Reported-by: Yiwen Jiang 
Reviewed-by: Junxiao Bi 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Tariq Saeed 
Cc: Junxiao Bi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ocfs2: unlock inode if deleting inode from orphan fails

2016-03-03T23:07:10+00:00

commit a4a8481ff68a8a324a878e281bc37f18665224f7 upstream.

When doing append direct io cleanup, if deleting inode fails, it goes
out without unlocking inode, which will cause the inode deadlock.

This issue was introduced by commit cf1776a9e834 ("ocfs2: fix a tiny
race when truncate dio orohaned entry").

Signed-off-by: Guozhonghua 
Signed-off-by: Joseph Qi 
Reviewed-by: Gang He 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Junxiao Bi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ocfs2/dlm: clear refmap bit of recovery lock while doing local recovery cleanup

2016-02-17T20:30:56+00:00

commit c95a51807b730e4681e2ecbdfd669ca52601959e upstream.

When recovery master down, dlm_do_local_recovery_cleanup() only remove
the $RECOVERY lock owned by dead node, but do not clear the refmap bit.
Which will make umount thread falling in dead loop migrating $RECOVERY
to the dead node.

Signed-off-by: xuejiufei 
Reviewed-by: Joseph Qi 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Junxiao Bi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ocfs2/dlm: ignore cleaning the migration mle that is inuse

2016-02-17T20:30:56+00:00

commit bef5502de074b6f6fa647b94b73155d675694420 upstream.

We have found that migration source will trigger a BUG that the refcount
of mle is already zero before put when the target is down during
migration.  The situation is as follows:

dlm_migrate_lockres
  dlm_add_migration_mle
  dlm_mark_lockres_migrating
  dlm_get_mle_inuse
  <<<<<< Now the refcount of the mle is 2.
  dlm_send_one_lockres and wait for the target to become the
  new master.
  <<<<<< o2hb detect the target down and clean the migration
  mle. Now the refcount is 1.

dlm_migrate_lockres woken, and put the mle twice when found the target
goes down which trigger the BUG with the following message:

  "ERROR: bad mle: ".

Signed-off-by: Jiufei Xue 
Reviewed-by: Joseph Qi 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Junxiao Bi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ocfs2: NFS hangs in __ocfs2_cluster_lock due to race with ocfs2_unblock_lock

2016-02-17T20:30:55+00:00

commit b1b1e15ef6b80facf76d6757649dfd7295eda29f upstream.

NFS on a 2 node ocfs2 cluster each node exporting dir.  The lock causing
the hang is the global bit map inode lock.  Node 1 is master, has the
lock granted in PR mode; Node 2 is in the converting list (PR -> EX).
There are no holders of the lock on the master node so it should
downconvert to NL and grant EX to node 2 but that does not happen.
BLOCKED + QUEUED in lock res are set and it is on osb blocked list.
Threads are waiting in __ocfs2_cluster_lock on BLOCKED.  One thread
wants EX, rest want PR.  So it is as though the downconvert thread needs
to be kicked to complete the conv.

The hang is caused by an EX req coming into __ocfs2_cluster_lock on the
heels of a PR req after it sets BUSY (drops l_lock, releasing EX
thread), forcing the incoming EX to wait on BUSY without doing anything.
PR has called ocfs2_dlm_lock, which sets the node 1 lock from NL -> PR,
queues ast.

At this time, upconvert (PR ->EX) arrives from node 2, finds conflict
with node 1 lock in PR, so the lock res is put on dlm thread's dirty
listt.

After ret from ocf2_dlm_lock, PR thread now waits behind EX on BUSY till
awoken by ast.

Now it is dlm_thread that serially runs dlm_shuffle_lists, ast, bast, in
that order.  dlm_shuffle_lists ques a bast on behalf of node 2 (which
will be run by dlm_thread right after the ast).  ast does its part, sets
UPCONVERT_FINISHING, clears BUSY and wakes its waiters.  Next,
dlm_thread runs bast.  It sets BLOCKED and kicks dc thread.  dc thread
runs ocfs2_unblock_lock, but since UPCONVERT_FINISHING set, skips doing
anything and reques.

Inside of __ocfs2_cluster_lock, since EX has been waiting on BUSY ahead
of PR, it wakes up first, finds BLOCKED set and skips doing anything but
clearing UPCONVERT_FINISHING (which was actually "meant" for the PR
thread), and this time waits on BLOCKED.  Next, the PR thread comes out
of wait but since UPCONVERT_FINISHING is not set, it skips updating the
l_ro_holders and goes straight to wait on BLOCKED.  So there, we have a
hang! Threads in __ocfs2_cluster_lock wait on BLOCKED, lock res in osb
blocked list.  Only when dc thread is awoken, it will run
ocfs2_unblock_lock and things will unhang.

One way to fix this is to wake the dc thread on the flag after clearing
UPCONVERT_FINISHING

Orabug: 20933419
Signed-off-by: Tariq Saeed 
Signed-off-by: Santosh Shilimkar 
Reviewed-by: Wengang Wang 
Reviewed-by: Mark Fasheh 
Cc: Joel Becker 
Cc: Junxiao Bi 
Reviewed-by: Joseph Qi 
Cc: Eric Ren 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ocfs2/dlm: clear migration_pending when migration target goes down

2015-12-30T01:45:49+00:00

We have found a BUG on res->migration_pending when migrating lock
resources.  The situation is as follows.

dlm_mark_lockres_migration
  res->migration_pending = 1;
  __dlm_lockres_reserve_ast
  dlm_lockres_release_ast returns with res->migration_pending remains
      because other threads reserve asts
  wait dlm_migration_can_proceed returns 1
  >>>>>>> o2hb found that target goes down and remove target
          from domain_map
  dlm_migration_can_proceed returns 1
  dlm_mark_lockres_migrating returns -ESHOTDOWN with
      res->migration_pending still remains.

When reentering dlm_mark_lockres_migrating(), it will trigger the BUG_ON
with res->migration_pending.  So clear migration_pending when target is
down.

Signed-off-by: Jiufei Xue 
Reviewed-by: Joseph Qi 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Junxiao Bi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ocfs2: fix flock panic issue

2015-12-30T01:45:49+00:00

Commit 4f6563677ae8 ("Move locks API users to locks_lock_inode_wait()")
move flock/posix lock indentify code to locks_lock_inode_wait(), but
missed to set fl_flags to FL_FLOCK which caused the following kernel
panic on 4.4.0_rc5.

  kernel BUG at fs/locks.c:1895!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: ocfs2(O) ocfs2_dlmfs(O) ocfs2_stack_o2cb(O) ocfs2_dlm(O) ocfs2_nodemanager(O) ocfs2_stackglue(O) iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi xen_kbdfront xen_netfront xen_fbfront xen_blkfront
  CPU: 0 PID: 20268 Comm: flock_unit_test Tainted: G           O    4.4.0-rc5-next-20151217 #1
  Hardware name: Xen HVM domU, BIOS 4.3.1OVM 05/14/2014
  task: ffff88007b3672c0 ti: ffff880028b58000 task.ti: ffff880028b58000
  RIP: locks_lock_inode_wait+0x2e/0x160
  Call Trace:
    ocfs2_do_flock+0x91/0x160 [ocfs2]
    ocfs2_flock+0x76/0xd0 [ocfs2]
    SyS_flock+0x10f/0x1a0
    entry_SYSCALL_64_fastpath+0x12/0x71
  Code: e5 41 57 41 56 49 89 fe 41 55 41 54 53 48 89 f3 48 81 ec 88 00 00 00 8b 46 40 83 e0 03 83 f8 01 0f 84 ad 00 00 00 83 f8 02 74 04 <0f> 0b eb fe 4c 8d ad 60 ff ff ff 4c 8d 7b 58 e8 0e 8e 73 00 4d
  RIP  locks_lock_inode_wait+0x2e/0x160
   RSP 
  ---[ end trace dfca74ec9b5b274c ]---

Fixes: 4f6563677ae8 ("Move locks API users to locks_lock_inode_wait()")
Signed-off-by: Junxiao Bi 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Joseph Qi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds