4.16-stable review patch. If anyone has any objections, please let me know.
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From: Ashish Samant ashish.samant@oracle.com
[ Upstream commit e4383029201470523c3ffe339bd7d57e9b4a7d65 ]
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@orac... 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 Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ocfs2/refcounttree.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
--- a/fs/ocfs2/refcounttree.c +++ b/fs/ocfs2/refcounttree.c @@ -4250,10 +4250,11 @@ out: static int ocfs2_reflink(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry, bool preserve) { - int error; + int error, had_lock; struct inode *inode = d_inode(old_dentry); struct buffer_head *old_bh = NULL; struct inode *new_orphan_inode = NULL; + struct ocfs2_lock_holder oh;
if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) return -EOPNOTSUPP; @@ -4295,6 +4296,14 @@ static int ocfs2_reflink(struct dentry * goto out; }
+ had_lock = ocfs2_inode_lock_tracker(new_orphan_inode, NULL, 1, + &oh); + if (had_lock < 0) { + error = had_lock; + mlog_errno(error); + goto out; + } + /* If the security isn't preserved, we need to re-initialize them. */ if (!preserve) { error = ocfs2_init_security_and_acl(dir, new_orphan_inode, @@ -4302,14 +4311,15 @@ static int ocfs2_reflink(struct dentry * if (error) mlog_errno(error); } -out: if (!error) { error = ocfs2_mv_orphaned_inode_to_new(dir, new_orphan_inode, new_dentry); if (error) mlog_errno(error); } + ocfs2_inode_unlock_tracker(new_orphan_inode, 1, &oh, had_lock);
+out: if (new_orphan_inode) { /* * We need to open_unlock the inode no matter whether we