linux-toradex.git/fs/ocfs2/dlmglue.c, branch v4.2.4

ocfs2: fix BUG in ocfs2_downconvert_thread_do_work()

2015-08-07T01:39:40+00:00

The "BUG_ON(list_empty(&osb->blocked_lock_list))" in
ocfs2_downconvert_thread_do_work can be triggered in the following case:

ocfs2dc has firstly saved osb->blocked_lock_count to local varibale
processed, and then processes the dentry lockres.  During the dentry
put, it calls iput and then deletes rw, inode and open lockres from
blocked list in ocfs2_mark_lockres_freeing.  And this causes the
variable `processed' to not reflect the number of blocked lockres to be
processed, which triggers the BUG.

Signed-off-by: Joseph Qi 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Revert "ocfs2: incorrect check for debugfs returns"

2015-04-21T16:17:28+00:00

This reverts commit e2ac55b6a8e337fac7cc59c6f452caac92ab5ee6.

Huang Ying reports that this causes a hang at boot with debugfs disabled.

It is true that the debugfs error checks are kind of confusing, and this
code certainly merits more cleanup and thinking about it, but there's
something wrong with the trivial "check not just for NULL, but for error
pointers too" patch.

Yes, with debugfs disabled, we will end up setting the o2hb_debug_dir
pointer variable to an error pointer (-ENODEV), and then continue as if
everything was fine.  But since debugfs is disabled, all the _users_ of
that pointer end up being compiled away, so even though the pointer can
not be dereferenced, that's still fine.

So it's confusing and somewhat questionable, but the "more correct"
error checks end up causing more trouble than they fix.

Reported-by: Huang Ying 
Acked-by: Andrew Morton 
Acked-by: Chengyu Song 
Signed-off-by: Linus Torvalds

ocfs2: check if the ocfs2 lock resource has been initialized before calling ocfs2_dlm_lock

2015-04-14T23:48:58+00:00

If ocfs2 lockres has not been initialized before calling ocfs2_dlm_lock,
the lock won't be dropped and then will lead umount hung.  The case is
described below:

ocfs2_mknod
    ocfs2_mknod_locked
        __ocfs2_mknod_locked
            ocfs2_journal_access_di
            Failed because of -ENOMEM or other reasons, the inode lockres
            has not been initialized yet.

    iput(inode)
        ocfs2_evict_inode
            ocfs2_delete_inode
                ocfs2_inode_lock
                    ocfs2_inode_lock_full_nested
                        __ocfs2_cluster_lock
                        Succeeds and allocates a new dlm lockres.
            ocfs2_clear_inode
                ocfs2_open_unlock
                    ocfs2_drop_inode_locks
                        ocfs2_drop_lock
                        Since lockres has not been initialized, the lock
                        can't be dropped and the lockres can't be
                        migrated, thus umount will hang forever.

Signed-off-by: Alex Chen 
Reviewed-by: Joseph Qi 
Reviewed-by: joyce.xue 
Cc: Mark Fasheh 
Cc: Joel Becker 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ocfs2: incorrect check for debugfs returns

2015-04-14T23:48:58+00:00

debugfs_create_dir and debugfs_create_file may return -ENODEV when debugfs
is not configured, so the return value should be checked against
ERROR_VALUE as well, otherwise the later dereference of the dentry pointer
would crash the kernel.

This patch tries to solve this problem by fixing certain checks. However,
I have that found other call sites are protected by #ifdef CONFIG_DEBUG_FS.
In current implementation, if CONFIG_DEBUG_FS is defined, then the above
two functions will never return any ERROR_VALUE. So another possibility
to fix this is to surround all the buggy checks/functions with the same
#ifdef CONFIG_DEBUG_FS. But I'm not sure if this would break any functionality,
as only OCFS2_FS_STATS declares dependency on DEBUG_FS.

Signed-off-by: Chengyu Song 
Cc: Mark Fasheh 
Cc: Joel Becker 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ocfs2: prune the dcache before deleting the dentry of directory

2015-02-10T22:30:30+00:00

In ocfs2_dentry_convert_worker, we should prune the dcache before deleting
the dentry of directory, otherwise, in the following cases the inode of
directory will still remain in orphan directory until the device being
umounted.

Mount point: /mnt/ocfs2
Node A                              Node B
mkdir /mnt/ocfs2/testdir
  ocfs2_mkdir
  ->ocfs2_mknod
  ->ocfs2_dentry_attach_lock
  ->ocfs2_dentry_lock(dentry, 0)
  ... ...
touch /mnt/ocfs2/testdir/testfile
                                    unlink /mnt/test/testdir/testfile
                                    rmdir /mnt/ocfs2/testdir
                                      ocfs2_unlink
                                      ->ocfs2_remote_dentry_delete
                                      ->ocfs2_dentry_lock(dentry, 1)
                                      ... ...
... ...
ocfs2_downconvert_thread
->ocfs2_unblock_lock
->ocfs2_dentry_convert_worker
->ocfs2_find_local_alias
  ->dget_dlock
->d_delete
Here the dentry can not be
released because the children's
dentry is negative but still exist.
Finally, this inode will still remain
in orphan directory until its children
are destroyed.

So before deleting dentry of directory, we should prune the dcache to
remove unused children of the parent dentry by shrink_dcache_parent().

Signed-off-by: Alex Chen 
Reviewed-by: Joseph Qi 
Reviewed-by: joyce.xue 
Reviewed-by: Mark Fasheh 
Cc: Joel Becker 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'akpm' (patchbomb from Andrew)

2014-12-11T02:34:42+00:00

Merge first patchbomb from Andrew Morton:
 - a few minor cifs fixes
 - dma-debug upadtes
 - ocfs2
 - slab
 - about half of MM
 - procfs
 - kernel/exit.c
 - panic.c tweaks
 - printk upates
 - lib/ updates
 - checkpatch updates
 - fs/binfmt updates
 - the drivers/rtc tree
 - nilfs
 - kmod fixes
 - more kernel/exit.c
 - various other misc tweaks and fixes

* emailed patches from Andrew Morton : (190 commits)
  exit: pidns: fix/update the comments in zap_pid_ns_processes()
  exit: pidns: alloc_pid() leaks pid_namespace if child_reaper is exiting
  exit: exit_notify: re-use "dead" list to autoreap current
  exit: reparent: call forget_original_parent() under tasklist_lock
  exit: reparent: avoid find_new_reaper() if no children
  exit: reparent: introduce find_alive_thread()
  exit: reparent: introduce find_child_reaper()
  exit: reparent: document the ->has_child_subreaper checks
  exit: reparent: s/while_each_thread/for_each_thread/ in find_new_reaper()
  exit: reparent: fix the cross-namespace PR_SET_CHILD_SUBREAPER reparenting
  exit: reparent: fix the dead-parent PR_SET_CHILD_SUBREAPER reparenting
  exit: proc: don't try to flush /proc/tgid/task/tgid
  exit: release_task: fix the comment about group leader accounting
  exit: wait: drop tasklist_lock before psig->c* accounting
  exit: wait: don't use zombie->real_parent
  exit: wait: cleanup the ptrace_reparented() checks
  usermodehelper: kill the kmod_thread_locker logic
  usermodehelper: don't use CLONE_VFORK for ____call_usermodehelper()
  fs/hfs/catalog.c: fix comparison bug in hfs_cat_keycmp
  nilfs2: fix the nilfs_iget() vs. nilfs_new_inode() races
  ...

ocfs2: do not set OCFS2_LOCK_UPCONVERT_FINISHING if nonblocking lock can not be granted at once

2014-12-11T01:41:03+00:00

ocfs2_readpages() use nonblocking flag to avoid page lock inversion.  It
will trigger cluster hang because that flag OCFS2_LOCK_UPCONVERT_FINISHING
is not cleared if nonblocking lock cannot be granted at once.  The flag
would prevent dc thread from downconverting.  So other nodes cannot
acheive this lockres for ever.

So we should not set OCFS2_LOCK_UPCONVERT_FINISHING when receiving ast if
nonblocking lock had already returned.

Signed-off-by: joyce.xue 
Reviewed-by: Junxiao Bi 
Cc: Mark Fasheh 
Cc: Joel Becker 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

assorted conversions to %p[dD]

2014-11-19T18:01:20+00:00

Signed-off-by: Al Viro

fs/ocfs2/dlmglue.c: use __seq_open_private() not seq_open()

2014-10-10T02:25:47+00:00

Reduce boilerplate code by using seq_open_private() instead of seq_open()

Signed-off-by: Rob Jones 
Cc: Joel Becker 
Cc: Mark Fasheh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ocfs2: remove some unused code

2014-06-04T23:53:55+00:00

dlm_recovery_ctxt.received is unused.

ocfs2_should_refresh_lock_res() can only return 0 or 1, so the error
handling code in ocfs2_super_lock() is unneeded.

Signed-off-by: joyce.xue 
Cc: Joel Becker 
Cc: Mark Fasheh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds