linux-imx

ocfs2: take inode cluster lock before moving reflinked inode from orphan dir

While reflinking an inode, we create a new inode in orphan directory,
then take EX lock on it, reflink the original inode to orphan inode and
release EX lock.  Once the lock is released another node could request
it in EX mode from ocfs2_recover_orphans() which causes downconvert of
the lock, on this node, to NL mode.

Later we attempt to initialize security acl for the orphan inode and
move it to the reflink destination.  However, while doing this we dont
take EX lock on the inode.  This could potentially cause problems
because we could be starting transaction, accessing journal and
modifying metadata of the inode while holding NL lock and with another
node holding EX lock on the inode.

Fix this by taking orphan inode cluster lock in EX mode before
initializing security and moving orphan inode to reflink destination.
Use the __tracker variant while taking inode lock to avoid recursive
locking in the ocfs2_init_security_and_acl() call chain.

Link: http://lkml.kernel.org/r/1523475107-7639-1-git-send-email-ashish.samant@oracle.com
Signed-off-by: Ashish Samant <ashish.samant@oracle.com>
Reviewed-by: Joseph Qi <jiangqi903@gmail.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Acked-by: Jun Piao <piaojun@huawei.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Changwei Ge <ge.changwei@h3c.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>