reiserfs: locking, release lock around quota operations

Previous commits released the write lock across quota operations but
missed several places.  In particular, the free operations can also
call into the file system code and take the write lock, causing
deadlocks.

This patch introduces some more helpers and uses them for quota call
sites.  Without this patch applied, reiserfs + quotas runs into deadlocks
under anything more than trivial load.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c
index 60d0932..bb20d79 100644
--- a/fs/reiserfs/super.c
+++ b/fs/reiserfs/super.c
@@ -243,6 +243,7 @@
 	done = 0;
 	REISERFS_SB(s)->s_is_unlinked_ok = 1;
 	while (!retval) {
+		int depth;
 		retval = search_item(s, &max_cpu_key, &path);
 		if (retval != ITEM_NOT_FOUND) {
 			reiserfs_error(s, "vs-2140",
@@ -298,9 +299,9 @@
 			retval = remove_save_link_only(s, &save_link_key, 0);
 			continue;
 		}
-		reiserfs_write_unlock(s);
+		depth = reiserfs_write_unlock_nested(inode->i_sb);
 		dquot_initialize(inode);
-		reiserfs_write_lock(s);
+		reiserfs_write_lock_nested(inode->i_sb, depth);
 
 		if (truncate && S_ISDIR(inode->i_mode)) {
 			/* We got a truncate request for a dir which is impossible.
@@ -356,10 +357,12 @@
 
 #ifdef CONFIG_QUOTA
 	/* Turn quotas off */
+	reiserfs_write_unlock(s);
 	for (i = 0; i < MAXQUOTAS; i++) {
 		if (sb_dqopt(s)->files[i] && quota_enabled[i])
 			dquot_quota_off(s, i);
 	}
+	reiserfs_write_lock(s);
 	if (ms_active_set)
 		/* Restore the flag back */
 		s->s_flags &= ~MS_ACTIVE;
@@ -2098,6 +2101,7 @@
 {
 	struct reiserfs_transaction_handle th;
 	int ret, err;
+	int depth;
 
 	reiserfs_write_lock(dquot->dq_sb);
 	ret =
@@ -2105,9 +2109,9 @@
 			  REISERFS_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
 	if (ret)
 		goto out;
-	reiserfs_write_unlock(dquot->dq_sb);
+	depth = reiserfs_write_unlock_nested(dquot->dq_sb);
 	ret = dquot_commit(dquot);
-	reiserfs_write_lock(dquot->dq_sb);
+	reiserfs_write_lock_nested(dquot->dq_sb, depth);
 	err =
 	    journal_end(&th, dquot->dq_sb,
 			REISERFS_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
@@ -2122,6 +2126,7 @@
 {
 	struct reiserfs_transaction_handle th;
 	int ret, err;
+	int depth;
 
 	reiserfs_write_lock(dquot->dq_sb);
 	ret =
@@ -2129,9 +2134,9 @@
 			  REISERFS_QUOTA_INIT_BLOCKS(dquot->dq_sb));
 	if (ret)
 		goto out;
-	reiserfs_write_unlock(dquot->dq_sb);
+	depth = reiserfs_write_unlock_nested(dquot->dq_sb);
 	ret = dquot_acquire(dquot);
-	reiserfs_write_lock(dquot->dq_sb);
+	reiserfs_write_lock_nested(dquot->dq_sb, depth);
 	err =
 	    journal_end(&th, dquot->dq_sb,
 			REISERFS_QUOTA_INIT_BLOCKS(dquot->dq_sb));
@@ -2184,15 +2189,16 @@
 {
 	struct reiserfs_transaction_handle th;
 	int ret, err;
+	int depth;
 
 	/* Data block + inode block */
 	reiserfs_write_lock(sb);
 	ret = journal_begin(&th, sb, 2);
 	if (ret)
 		goto out;
-	reiserfs_write_unlock(sb);
+	depth = reiserfs_write_unlock_nested(sb);
 	ret = dquot_commit_info(sb, type);
-	reiserfs_write_lock(sb);
+	reiserfs_write_lock_nested(sb, depth);
 	err = journal_end(&th, sb, 2);
 	if (!ret && err)
 		ret = err;