ext4: use common helpers in all places reading metadata buffers

Revome all open codes that read metadata buffers, switch to use
ext4_read_bh_*() common helpers.

Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Suggested-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200924073337.861472-4-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/balloc.c

@@ -494,12 +494,10 @@ ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group,
 	 * submit the buffer_head for reading
 	 */
 	set_buffer_new(bh);
-	clear_buffer_verified(bh);
 	trace_ext4_read_block_bitmap_load(sb, block_group, ignore_locked);
-	bh->b_end_io = ext4_end_bitmap_read;
+	ext4_read_bh_nowait(bh, REQ_META | REQ_PRIO |
-	get_bh(bh);
+			    (ignore_locked ? REQ_RAHEAD : 0),
-	submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO |
+			    ext4_end_bitmap_read);
-		  (ignore_locked ? REQ_RAHEAD : 0), bh);
 	return bh;
 verify:
 	err = ext4_validate_block_bitmap(sb, desc, block_group, bh);

fs/ext4/extents.c

@@ -501,8 +501,7 @@ __read_extent_tree_block(const char *function, unsigned int line,
 
 	if (!bh_uptodate_or_lock(bh)) {
 		trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
-		clear_buffer_verified(bh);
+		err = ext4_read_bh(bh, 0, NULL);
-		err = bh_submit_read(bh);
 		if (err < 0)
 			goto errout;
 	}

fs/ext4/ialloc.c

@@ -188,12 +188,8 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 	/*
 	 * submit the buffer_head for reading
 	 */
-	clear_buffer_verified(bh);
 	trace_ext4_load_inode_bitmap(sb, block_group);
-	bh->b_end_io = ext4_end_bitmap_read;
+	ext4_read_bh(bh, REQ_META | REQ_PRIO, ext4_end_bitmap_read);
-	get_bh(bh);
-	submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
-	wait_on_buffer(bh);
 	ext4_simulate_fail_bh(sb, bh, EXT4_SIM_IBITMAP_EIO);
 	if (!buffer_uptodate(bh)) {
 		put_bh(bh);

fs/ext4/indirect.c

@@ -163,7 +163,7 @@ static Indirect *ext4_get_branch(struct inode *inode, int depth,
 		}
 
 		if (!bh_uptodate_or_lock(bh)) {
-			if (bh_submit_read(bh) < 0) {
+			if (ext4_read_bh(bh, 0, NULL) < 0) {
 				put_bh(bh);
 				goto failure;
 			}

fs/ext4/inode.c

@@ -878,19 +878,20 @@ struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
 			       ext4_lblk_t block, int map_flags)
 {
 	struct buffer_head *bh;
+	int ret;
 
 	bh = ext4_getblk(handle, inode, block, map_flags);
 	if (IS_ERR(bh))
 		return bh;
 	if (!bh || ext4_buffer_uptodate(bh))
 		return bh;
-	clear_buffer_verified(bh);
+
-	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &bh);
+	ret = ext4_read_bh_lock(bh, REQ_META | REQ_PRIO, true);
-	wait_on_buffer(bh);
+	if (ret) {
-	if (buffer_uptodate(bh))
-		return bh;
 		put_bh(bh);
-	return ERR_PTR(-EIO);
+		return ERR_PTR(ret);
+	}
+	return bh;
 }
 
 /* Read a contiguous batch of blocks. */
@@ -910,11 +911,8 @@ int ext4_bread_batch(struct inode *inode, ext4_lblk_t block, int bh_count,
 
 	for (i = 0; i < bh_count; i++)
 		/* Note that NULL bhs[i] is valid because of holes. */
-		if (bhs[i] && !ext4_buffer_uptodate(bhs[i])) {
+		if (bhs[i] && !ext4_buffer_uptodate(bhs[i]))
-			clear_buffer_verified(bhs[i]);
+			ext4_read_bh_lock(bhs[i], REQ_META | REQ_PRIO, false);
-			ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1,
-				    &bhs[i]);
-		}
 
 	if (!wait)
 		return 0;
@@ -1084,7 +1082,7 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
 		if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
 		    !buffer_unwritten(bh) &&
 		    (block_start < from || block_end > to)) {
-			ll_rw_block(REQ_OP_READ, 0, 1, &bh);
+			ext4_read_bh_lock(bh, 0, false);
 			wait[nr_wait++] = bh;
 		}
 	}
@@ -3756,11 +3754,8 @@ static int __ext4_block_zero_page_range(handle_t *handle,
 		set_buffer_uptodate(bh);
 
 	if (!buffer_uptodate(bh)) {
-		err = -EIO;
+		err = ext4_read_bh_lock(bh, 0, true);
-		ll_rw_block(REQ_OP_READ, 0, 1, &bh);
+		if (err)
-		wait_on_buffer(bh);
-		/* Uhhuh. Read error. Complain and punt. */
-		if (!buffer_uptodate(bh))
 			goto unlock;
 		if (fscrypt_inode_uses_fs_layer_crypto(inode)) {
 			/* We expect the key to be set. */
@@ -4404,9 +4399,7 @@ make_io:
 		 * Read the block from disk.
 		 */
 		trace_ext4_load_inode(inode);
-		get_bh(bh);
+		ext4_read_bh_nowait(bh, REQ_META | REQ_PRIO, NULL);
-		bh->b_end_io = end_buffer_read_sync;
-		submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
 		blk_finish_plug(&plug);
 		wait_on_buffer(bh);
 		if (!buffer_uptodate(bh)) {

fs/ext4/mmp.c

@@ -85,15 +85,11 @@ static int read_mmp_block(struct super_block *sb, struct buffer_head **bh,
 		}
 	}
 
-	get_bh(*bh);
 	lock_buffer(*bh);
-	(*bh)->b_end_io = end_buffer_read_sync;
+	ret = ext4_read_bh(*bh, REQ_META | REQ_PRIO, NULL);
-	submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, *bh);
+	if (ret)
-	wait_on_buffer(*bh);
-	if (!buffer_uptodate(*bh)) {
-		ret = -EIO;
 		goto warn_exit;
-	}
+
 	mmp = (struct mmp_struct *)((*bh)->b_data);
 	if (le32_to_cpu(mmp->mmp_magic) != EXT4_MMP_MAGIC) {
 		ret = -EFSCORRUPTED;

fs/ext4/move_extent.c

@@ -215,7 +215,7 @@ mext_page_mkuptodate(struct page *page, unsigned from, unsigned to)
 	for (i = 0; i < nr; i++) {
 		bh = arr[i];
 		if (!bh_uptodate_or_lock(bh)) {
-			err = bh_submit_read(bh);
+			err = ext4_read_bh(bh, 0, NULL);
 			if (err)
 				return err;
 		}

fs/ext4/resize.c

@@ -1245,7 +1245,7 @@ static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block)
 	if (unlikely(!bh))
 		return NULL;
 	if (!bh_uptodate_or_lock(bh)) {
-		if (bh_submit_read(bh) < 0) {
+		if (ext4_read_bh(bh, 0, NULL) < 0) {
 			brelse(bh);
 			return NULL;
 		}

fs/ext4/super.c

@@ -212,19 +212,21 @@ int ext4_read_bh_lock(struct buffer_head *bh, int op_flags, bool wait)
 struct buffer_head *
 ext4_sb_bread(struct super_block *sb, sector_t block, int op_flags)
 {
-	struct buffer_head *bh = sb_getblk(sb, block);
+	struct buffer_head *bh;
+	int ret;
 
+	bh = sb_getblk(sb, block);
 	if (bh == NULL)
 		return ERR_PTR(-ENOMEM);
 	if (ext4_buffer_uptodate(bh))
 		return bh;
-	clear_buffer_verified(bh);
+
-	ll_rw_block(REQ_OP_READ, REQ_META | op_flags, 1, &bh);
+	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
-	wait_on_buffer(bh);
+	if (ret) {
-	if (buffer_uptodate(bh))
-		return bh;
 		put_bh(bh);
-	return ERR_PTR(-EIO);
+		return ERR_PTR(ret);
+	}
+	return bh;
 }
 
 static int ext4_verify_csum_type(struct super_block *sb,
@@ -5176,9 +5178,7 @@ static journal_t *ext4_get_dev_journal(struct super_block *sb,
 		goto out_bdev;
 	}
 	journal->j_private = sb;
-	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
+	if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
-	wait_on_buffer(journal->j_sb_buffer);
-	if (!buffer_uptodate(journal->j_sb_buffer)) {
 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
 		goto out_journal;
 	}