[PATCH] xfs: convert quotacheck to attach dquot buffers

["Darrick J. Wong" <djwong@xxxxxxxxxx>]

Now that we've converted the dquot logging machinery to attach the dquot
buffer to the li_buf pointer so that the AIL dqflush doesn't have to
allocate or read buffers in a reclaim path, do the same for the
quotacheck code so that the reclaim shrinker dqflush call doesn't have
to do that either.

Cc: <stable@xxxxxxxxxxxxxxx> # v6.12
Fixes: 903edea6c53f09 ("mm: warn about illegal __GFP_NOFAIL usage in a more appropriate location and manner")
Signed-off-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>

diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
index 708fd3358375..f11d475898f2 100644
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -1285,11 +1285,10 @@ xfs_qm_dqflush_check(
  * Requires dquot flush lock, will clear the dirty flag, delete the quota log
  * item from the AIL, and shut down the system if something goes wrong.
  */
-int
+static int
 xfs_dquot_read_buf(
 	struct xfs_trans	*tp,
 	struct xfs_dquot	*dqp,
-	xfs_buf_flags_t		xbf_flags,
 	struct xfs_buf		**bpp)
 {
 	struct xfs_mount	*mp = dqp->q_mount;
@@ -1297,10 +1296,8 @@ xfs_dquot_read_buf(
 	int			error;
 
 	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, dqp->q_blkno,
-				   mp->m_quotainfo->qi_dqchunklen, xbf_flags,
+				   mp->m_quotainfo->qi_dqchunklen, 0,
 				   &bp, &xfs_dquot_buf_ops);
-	if (error == -EAGAIN)
-		return error;
 	if (xfs_metadata_is_sick(error))
 		xfs_dquot_mark_sick(dqp);
 	if (error)
@@ -1334,7 +1331,7 @@ xfs_dquot_attach_buf(
 		struct xfs_buf	*bp = NULL;
 
 		spin_unlock(&qlip->qli_lock);
-		error = xfs_dquot_read_buf(tp, dqp, 0, &bp);
+		error = xfs_dquot_read_buf(tp, dqp, &bp);
 		if (error)
 			return error;
 
diff --git a/fs/xfs/xfs_dquot.h b/fs/xfs/xfs_dquot.h
index c7e80fc90823..c617bac75361 100644
--- a/fs/xfs/xfs_dquot.h
+++ b/fs/xfs/xfs_dquot.h
@@ -214,8 +214,6 @@ void xfs_dquot_to_disk(struct xfs_disk_dquot *ddqp, struct xfs_dquot *dqp);
 #define XFS_DQ_IS_DIRTY(dqp)	((dqp)->q_flags & XFS_DQFLAG_DIRTY)
 
 void		xfs_qm_dqdestroy(struct xfs_dquot *dqp);
-int		xfs_dquot_read_buf(struct xfs_trans *tp, struct xfs_dquot *dqp,
-				xfs_buf_flags_t flags, struct xfs_buf **bpp);
 int		xfs_qm_dqflush(struct xfs_dquot *dqp, struct xfs_buf *bp);
 void		xfs_qm_dqunpin_wait(struct xfs_dquot *dqp);
 void		xfs_qm_adjust_dqtimers(struct xfs_dquot *d);
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index 7d07d4b5c339..69b70c3e999d 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -148,13 +148,13 @@ xfs_qm_dqpurge(
 		 * We don't care about getting disk errors here. We need
 		 * to purge this dquot anyway, so we go ahead regardless.
 		 */
-		error = xfs_dquot_read_buf(NULL, dqp, XBF_TRYLOCK, &bp);
+		error = xfs_dquot_use_attached_buf(dqp, &bp);
 		if (error == -EAGAIN) {
 			xfs_dqfunlock(dqp);
 			dqp->q_flags &= ~XFS_DQFLAG_FREEING;
 			goto out_unlock;
 		}
-		if (error)
+		if (!bp)
 			goto out_funlock;
 
 		/*
@@ -506,8 +506,8 @@ xfs_qm_dquot_isolate(
 		/* we have to drop the LRU lock to flush the dquot */
 		spin_unlock(&lru->lock);
 
-		error = xfs_dquot_read_buf(NULL, dqp, XBF_TRYLOCK, &bp);
-		if (error) {
+		error = xfs_dquot_use_attached_buf(dqp, &bp);
+		if (!bp || error == -EAGAIN) {
 			xfs_dqfunlock(dqp);
 			goto out_unlock_dirty;
 		}
@@ -1331,6 +1331,10 @@ xfs_qm_quotacheck_dqadjust(
 		return error;
 	}
 
+	error = xfs_dquot_attach_buf(NULL, dqp);
+	if (error)
+		return error;
+
 	trace_xfs_dqadjust(dqp);
 
 	/*
@@ -1513,9 +1517,13 @@ xfs_qm_flush_one(
 		goto out_unlock;
 	}
 
-	error = xfs_dquot_read_buf(NULL, dqp, XBF_TRYLOCK, &bp);
+	error = xfs_dquot_use_attached_buf(dqp, &bp);
 	if (error)
 		goto out_unlock;
+	if (!bp) {
+		error = -EFSCORRUPTED;
+		goto out_unlock;
+	}
 
 	error = xfs_qm_dqflush(dqp, bp);
 	if (!error)