gfs2: replace ll_rw_block()

ll_rw_block() is not safe for the sync read path because it cannot
guarantee that always submitting read IO if the buffer has been locked,
so stop using it. We also switch to new bh_readahead() helper for the
readahead path.

Link: https://lkml.kernel.org/r/20220901133505.2510834-5-yi.zhang@huawei.comSigned-off-by: NZhang Yi <yi.zhang@huawei.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NAndreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

fs/gfs2/meta_io.c

@@ -525,8 +525,7 @@ struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
 
 	if (buffer_uptodate(first_bh))
 		goto out;
-	if (!buffer_locked(first_bh))
-		ll_rw_block(REQ_OP_READ | REQ_META | REQ_PRIO, 1, &first_bh);
+	bh_read_nowait(first_bh, REQ_META | REQ_PRIO);
 
 	dblock++;
 	extlen--;
@@ -534,9 +533,7 @@ struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
 	while (extlen) {
 		bh = gfs2_getbuf(gl, dblock, CREATE);
 
-		if (!buffer_uptodate(bh) && !buffer_locked(bh))
-			ll_rw_block(REQ_OP_READ | REQ_RAHEAD | REQ_META |
-				    REQ_PRIO, 1, &bh);
+		bh_readahead(bh, REQ_RAHEAD | REQ_META | REQ_PRIO);
 		brelse(bh);
 		dblock++;
 		extlen--;

fs/gfs2/quota.c

@@ -745,12 +745,8 @@ static int gfs2_write_buf_to_page(struct gfs2_inode *ip, unsigned long index,
 		}
 		if (PageUptodate(page))
 			set_buffer_uptodate(bh);
-		if (!buffer_uptodate(bh)) {
-			ll_rw_block(REQ_OP_READ | REQ_META | REQ_PRIO, 1, &bh);
-			wait_on_buffer(bh);
-			if (!buffer_uptodate(bh))
-				goto unlock_out;
-		}
+		if (bh_read(bh, REQ_META | REQ_PRIO) < 0)
+			goto unlock_out;
 		if (gfs2_is_jdata(ip))
 			gfs2_trans_add_data(ip->i_gl, bh);
 		else