[PATCH v1 13/16] iomap: add a private arg for read and readahead

[Joanne Koong <joannelkoong@gmail.com>]

Add a void *private arg for read and readahead which filesystems that
pass in custom read callbacks can use. Stash this in the existing
private field in the iomap_iter.

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
---
 block/fops.c           | 4 ++--
 fs/erofs/data.c        | 4 ++--
 fs/gfs2/aops.c         | 4 ++--
 fs/iomap/buffered-io.c | 8 ++++++--
 fs/xfs/xfs_aops.c      | 4 ++--
 fs/zonefs/file.c       | 4 ++--
 include/linux/iomap.h  | 4 ++--
 7 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/block/fops.c b/block/fops.c
index b42e16d0eb35..57ae886c7b1a 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -533,12 +533,12 @@ const struct address_space_operations def_blk_aops = {
 #else /* CONFIG_BUFFER_HEAD */
 static int blkdev_read_folio(struct file *file, struct folio *folio)
 {
-	return iomap_read_folio(folio, &blkdev_iomap_ops, NULL);
+	return iomap_read_folio(folio, &blkdev_iomap_ops, NULL, NULL);
 }
 
 static void blkdev_readahead(struct readahead_control *rac)
 {
-	iomap_readahead(rac, &blkdev_iomap_ops, NULL);
+	iomap_readahead(rac, &blkdev_iomap_ops, NULL, NULL);
 }
 
 static ssize_t blkdev_writeback_range(struct iomap_writepage_ctx *wpc,
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index ea451f233263..2ea338448ca1 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -371,7 +371,7 @@ static int erofs_read_folio(struct file *file, struct folio *folio)
 {
 	trace_erofs_read_folio(folio, true);
 
-	return iomap_read_folio(folio, &erofs_iomap_ops, NULL);
+	return iomap_read_folio(folio, &erofs_iomap_ops, NULL, NULL);
 }
 
 static void erofs_readahead(struct readahead_control *rac)
@@ -379,7 +379,7 @@ static void erofs_readahead(struct readahead_control *rac)
 	trace_erofs_readahead(rac->mapping->host, readahead_index(rac),
 					readahead_count(rac), true);
 
-	return iomap_readahead(rac, &erofs_iomap_ops, NULL);
+	return iomap_readahead(rac, &erofs_iomap_ops, NULL, NULL);
 }
 
 static sector_t erofs_bmap(struct address_space *mapping, sector_t block)
diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
index bf531bcfd8a0..211a0f7b1416 100644
--- a/fs/gfs2/aops.c
+++ b/fs/gfs2/aops.c
@@ -428,7 +428,7 @@ static int gfs2_read_folio(struct file *file, struct folio *folio)
 
 	if (!gfs2_is_jdata(ip) ||
 	    (i_blocksize(inode) == PAGE_SIZE && !folio_buffers(folio))) {
-		error = iomap_read_folio(folio, &gfs2_iomap_ops, NULL);
+		error = iomap_read_folio(folio, &gfs2_iomap_ops, NULL, NULL);
 	} else if (gfs2_is_stuffed(ip)) {
 		error = stuffed_read_folio(ip, folio);
 	} else {
@@ -503,7 +503,7 @@ static void gfs2_readahead(struct readahead_control *rac)
 	else if (gfs2_is_jdata(ip))
 		mpage_readahead(rac, gfs2_block_map);
 	else
-		iomap_readahead(rac, &gfs2_iomap_ops, NULL);
+		iomap_readahead(rac, &gfs2_iomap_ops, NULL, NULL);
 }
 
 /**
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 06f2c857de64..d68dd7f63923 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -539,12 +539,13 @@ static void iomap_readfolio_complete(const struct iomap_iter *iter,
 }
 
 int iomap_read_folio(struct folio *folio, const struct iomap_ops *ops,
-		const struct iomap_read_ops *read_ops)
+		const struct iomap_read_ops *read_ops, void *private)
 {
 	struct iomap_iter iter = {
 		.inode		= folio->mapping->host,
 		.pos		= folio_pos(folio),
 		.len		= folio_size(folio),
+		.private	= private,
 	};
 	struct iomap_readfolio_ctx ctx = {
 		.cur_folio	= folio,
@@ -591,6 +592,8 @@ static int iomap_readahead_iter(struct iomap_iter *iter,
  * @rac: Describes the pages to be read.
  * @ops: The operations vector for the filesystem.
  * @read_ops: Optional ops callers can pass in if they want custom handling.
+ * @private: If passed in, this will be usable by the caller in any
+ * read_ops callbacks.
  *
  * This function is for filesystems to call to implement their readahead
  * address_space operation.
@@ -603,12 +606,13 @@ static int iomap_readahead_iter(struct iomap_iter *iter,
  * the filesystem to be reentered.
  */
 void iomap_readahead(struct readahead_control *rac, const struct iomap_ops *ops,
-		const struct iomap_read_ops *read_ops)
+		const struct iomap_read_ops *read_ops, void *private)
 {
 	struct iomap_iter iter = {
 		.inode	= rac->mapping->host,
 		.pos	= readahead_pos(rac),
 		.len	= readahead_length(rac),
+		.private = private,
 	};
 	struct iomap_readfolio_ctx ctx = {
 		.rac	= rac,
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index fb2150c0825a..5e71a3888e6d 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -742,14 +742,14 @@ xfs_vm_read_folio(
 	struct file		*unused,
 	struct folio		*folio)
 {
-	return iomap_read_folio(folio, &xfs_read_iomap_ops, NULL);
+	return iomap_read_folio(folio, &xfs_read_iomap_ops, NULL, NULL);
 }
 
 STATIC void
 xfs_vm_readahead(
 	struct readahead_control	*rac)
 {
-	iomap_readahead(rac, &xfs_read_iomap_ops, NULL);
+	iomap_readahead(rac, &xfs_read_iomap_ops, NULL, NULL);
 }
 
 static int
diff --git a/fs/zonefs/file.c b/fs/zonefs/file.c
index 96470daf4d3f..182bb473a82b 100644
--- a/fs/zonefs/file.c
+++ b/fs/zonefs/file.c
@@ -112,12 +112,12 @@ static const struct iomap_ops zonefs_write_iomap_ops = {
 
 static int zonefs_read_folio(struct file *unused, struct folio *folio)
 {
-	return iomap_read_folio(folio, &zonefs_read_iomap_ops, NULL);
+	return iomap_read_folio(folio, &zonefs_read_iomap_ops, NULL, NULL);
 }
 
 static void zonefs_readahead(struct readahead_control *rac)
 {
-	iomap_readahead(rac, &zonefs_read_iomap_ops, NULL);
+	iomap_readahead(rac, &zonefs_read_iomap_ops, NULL, NULL);
 }
 
 /*
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index a7247439aeb5..9bc7900dd448 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -355,9 +355,9 @@ ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
 		const struct iomap_ops *ops,
 		const struct iomap_write_ops *write_ops, void *private);
 int iomap_read_folio(struct folio *folio, const struct iomap_ops *ops,
-		const struct iomap_read_ops *read_ops);
+		const struct iomap_read_ops *read_ops, void *private);
 void iomap_readahead(struct readahead_control *, const struct iomap_ops *ops,
-		const struct iomap_read_ops *read_ops);
+		const struct iomap_read_ops *read_ops, void *private);
 bool iomap_is_partially_uptodate(struct folio *, size_t from, size_t count);
 struct folio *iomap_get_folio(struct iomap_iter *iter, loff_t pos, size_t len);
 bool iomap_release_folio(struct folio *folio, gfp_t gfp_flags);
-- 
2.47.3