[RFC PATCH v3 21/26] ext4: implement zero_range iomap path

[Zhang Yi <yi.zhang@huaweicloud.com>]

From: Zhang Yi <yi.zhang@huawei.com>

Implement zero_range iomap path, add ext4_iomap_zero_range() to zero
out the already mapped blocks, everything have been done in
iomap_zero_range(), so invoke it directly.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
---
 fs/ext4/inode.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index dee661e64a69..f8e9f566ef6a 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4126,6 +4126,13 @@ static int __ext4_block_zero_page_range(handle_t *handle,
 	return err;
 }
 
+static int ext4_iomap_zero_range(struct inode *inode,
+				 loff_t from, loff_t length)
+{
+	return iomap_zero_range(inode, from, length, NULL,
+				&ext4_iomap_buffered_read_ops);
+}
+
 /*
  * ext4_block_zero_page_range() zeros out a mapping of length 'length'
  * starting from file offset 'from'.  The range to be zero'd must
@@ -4151,6 +4158,8 @@ static int ext4_block_zero_page_range(handle_t *handle,
 	if (IS_DAX(inode)) {
 		return dax_zero_range(inode, from, length, NULL,
 				      &ext4_iomap_ops);
+	} else if (ext4_test_inode_state(inode, EXT4_STATE_BUFFERED_IOMAP)) {
+		return ext4_iomap_zero_range(inode, from, length);
 	}
 	return __ext4_block_zero_page_range(handle, mapping, from, length);
 }
-- 
2.39.2