[PATCH 14/14] iomap: pass the length of the dirty region to ->map_blocks

[Christoph Hellwig <hch@xxxxxx>]

Let the file system know how much dirty data exists at the passed
in offset.  This allows file systems to allocate the right amount
of space that actually is written back if they can't eagerly
convert (e.g. because they don't support unwritten extents).

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 block/fops.c           | 2 +-
 fs/gfs2/bmap.c         | 2 +-
 fs/iomap/buffered-io.c | 2 +-
 fs/xfs/xfs_aops.c      | 3 ++-
 fs/zonefs/file.c       | 3 ++-
 include/linux/iomap.h  | 2 +-
 6 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/block/fops.c b/block/fops.c
index 0abaac705dafb0..7e921f999182dc 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -467,7 +467,7 @@ static void blkdev_readahead(struct readahead_control *rac)
 }
 
 static int blkdev_map_blocks(struct iomap_writepage_ctx *wpc,
-		struct inode *inode, loff_t offset)
+		struct inode *inode, loff_t offset, unsigned int len)
 {
 	loff_t isize = i_size_read(inode);
 
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index d9ccfd27e4f11f..789af5c8fade9d 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -2465,7 +2465,7 @@ int __gfs2_punch_hole(struct file *file, loff_t offset, loff_t length)
 }
 
 static int gfs2_map_blocks(struct iomap_writepage_ctx *wpc, struct inode *inode,
-		loff_t offset)
+		loff_t offset, unsigned int len)
 {
 	int ret;
 
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index d8f56968962b97..e0c9cede82ee4b 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1783,7 +1783,7 @@ static int iomap_writepage_map_blocks(struct iomap_writepage_ctx *wpc,
 	do {
 		unsigned map_len;
 
-		error = wpc->ops->map_blocks(wpc, inode, pos);
+		error = wpc->ops->map_blocks(wpc, inode, pos, dirty_len);
 		if (error)
 			break;
 		trace_iomap_writepage_map(inode, &wpc->iomap);
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index b45ee6cbbdaab2..bf26a91ecdbbc6 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -276,7 +276,8 @@ static int
 xfs_map_blocks(
 	struct iomap_writepage_ctx *wpc,
 	struct inode		*inode,
-	loff_t			offset)
+	loff_t			offset,
+	unsigned int		len)
 {
 	struct xfs_inode	*ip = XFS_I(inode);
 	struct xfs_mount	*mp = ip->i_mount;
diff --git a/fs/zonefs/file.c b/fs/zonefs/file.c
index b2c9b35df8f76d..1526e0ec6bfeaf 100644
--- a/fs/zonefs/file.c
+++ b/fs/zonefs/file.c
@@ -125,7 +125,8 @@ static void zonefs_readahead(struct readahead_control *rac)
  * which implies that the page range can only be within the fixed inode size.
  */
 static int zonefs_write_map_blocks(struct iomap_writepage_ctx *wpc,
-				   struct inode *inode, loff_t offset)
+				   struct inode *inode, loff_t offset,
+				   unsigned int len)
 {
 	struct zonefs_zone *z = zonefs_inode_zone(inode);
 
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 49d93f53878565..6fc1c858013d1e 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -318,7 +318,7 @@ struct iomap_writeback_ops {
 	 * by the file system if it is still valid.
 	 */
 	int (*map_blocks)(struct iomap_writepage_ctx *wpc, struct inode *inode,
-				loff_t offset);
+			  loff_t offset, unsigned len);
 
 	/*
 	 * Optional, allows the file systems to perform actions just before
-- 
2.39.2