From bc8e5f07392f05c47c8bdeff4f7098db440d065c Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Thu, 13 May 2010 19:58:50 +0200 Subject: quota: Refactor dquot_transfer code so that OCFS2 can pass in its references Currently, __dquot_transfer() acquires its own references of dquot structures that will be put into inode. But for OCFS2, this creates a lock inversion between dq_lock (waited on in dqget) and transaction start (started in ocfs2_setattr). Currently, deadlock is impossible because dq_lock is acquired only during dquot_acquire and dquot_release and we already hold a reference to dquot structures in ocfs2_setattr so neither of these functions can be called while we call dquot_transfer. But this is rather subtle and it is hard to teach lockdep about it. So provide __dquot_transfer function that can be passed dquot references directly. OCFS2 can then pass acquired dquot references directly to __dquot_transfer with proper locking. Signed-off-by: Jan Kara --- include/linux/quotaops.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/quotaops.h b/include/linux/quotaops.h index 8a7818764a67..370abb1e99cb 100644 --- a/include/linux/quotaops.h +++ b/include/linux/quotaops.h @@ -76,6 +76,7 @@ int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct fs_disk_quota *di); +int __dquot_transfer(struct inode *inode, struct dquot **transfer_to); int dquot_transfer(struct inode *inode, struct iattr *iattr); int vfs_dq_quota_on_remount(struct super_block *sb); -- cgit v1.2.2