1 files changed, 75 insertions, 7 deletions

diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index 0e1d4be5865a..e137d96f1b17 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -187,6 +187,52 @@ struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
 	return bh;
 }
 
+static void gfs2_meta_read_endio(struct bio *bio)
+{
+	struct bio_vec *bvec;
+	int i;
+
+	bio_for_each_segment_all(bvec, bio, i) {
+		struct page *page = bvec->bv_page;
+		struct buffer_head *bh = page_buffers(page);
+		unsigned int len = bvec->bv_len;
+
+		while (bh_offset(bh) < bvec->bv_offset)
+			bh = bh->b_this_page;
+		do {
+			struct buffer_head *next = bh->b_this_page;
+			len -= bh->b_size;
+			bh->b_end_io(bh, !bio->bi_error);
+			bh = next;
+		} while (bh && len);
+	}
+	bio_put(bio);
+}
+
+/*
+ * Submit several consecutive buffer head I/O requests as a single bio I/O
+ * request.  (See submit_bh_wbc.)
+ */
+static void gfs2_submit_bhs(int rw, struct buffer_head *bhs[], int num)
+{
+	struct buffer_head *bh = bhs[0];
+	struct bio *bio;
+	int i;
+
+	if (!num)
+		return;
+
+	bio = bio_alloc(GFP_NOIO, num);
+	bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
+	bio->bi_bdev = bh->b_bdev;
+	for (i = 0; i < num; i++) {
+		bh = bhs[i];
+		bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh));
+	}
+	bio->bi_end_io = gfs2_meta_read_endio;
+	submit_bio(rw, bio);
+}
+
 /**
  * gfs2_meta_read - Read a block from disk
  * @gl: The glock covering the block
@@ -198,10 +244,11 @@ struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
  */
 
 int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
-		   struct buffer_head **bhp)
+		   int rahead, struct buffer_head **bhp)
 {
 	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
-	struct buffer_head *bh;
+	struct buffer_head *bh, *bhs[2];
+	int num = 0;
 
 	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) {
 		*bhp = NULL;
@@ -213,14 +260,31 @@ int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
 	lock_buffer(bh);
 	if (buffer_uptodate(bh)) {
 		unlock_buffer(bh);
-		return 0;
+		flags &= ~DIO_WAIT;
+	} else {
+		bh->b_end_io = end_buffer_read_sync;
+		get_bh(bh);
+		bhs[num++] = bh;
 	}
-	bh->b_end_io = end_buffer_read_sync;
-	get_bh(bh);
-	submit_bh(READ_SYNC | REQ_META | REQ_PRIO, bh);
+
+	if (rahead) {
+		bh = gfs2_getbuf(gl, blkno + 1, CREATE);
+
+		lock_buffer(bh);
+		if (buffer_uptodate(bh)) {
+			unlock_buffer(bh);
+			brelse(bh);
+		} else {
+			bh->b_end_io = end_buffer_read_sync;
+			bhs[num++] = bh;
+		}
+	}
+
+	gfs2_submit_bhs(READ_SYNC | REQ_META | REQ_PRIO, bhs, num);
 	if (!(flags & DIO_WAIT))
 		return 0;
 
+	bh = *bhp;
 	wait_on_buffer(bh);
 	if (unlikely(!buffer_uptodate(bh))) {
 		struct gfs2_trans *tr = current->journal_info;
@@ -341,8 +405,12 @@ int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
 	struct buffer_head *bh;
 	int ret = 0;
 	u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
+	int rahead = 0;
+
+	if (num == ip->i_no_addr)
+		rahead = ip->i_rahead;
 
-	ret = gfs2_meta_read(gl, num, DIO_WAIT, &bh);
+	ret = gfs2_meta_read(gl, num, DIO_WAIT, rahead, &bh);
 	if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
 		brelse(bh);
 		ret = -EIO;