[RFC,11/18] iomap: add a fs private parameter to iomap_ioend

Commit Message

Zhang Yi Nov. 23, 2023, 12:51 p.m. UTC

From: Zhang Yi <[e-mail]>

Add a private parameter to iomap_ioend structure, letting filesystems
can pass something they needed from .prepare_ioend() to IO end.

Signed-off-by: Zhang Yi <[e-mail]>
---
 fs/iomap/buffered-io.c | 1 +
 include/linux/iomap.h  | 1 +
 2 files changed, 2 insertions(+)

Comments

Christoph Hellwig Nov. 23, 2023, 3:36 p.m. UTC | #1

On Thu, Nov 23, 2023 at 08:51:13PM +0800, Zhang Yi wrote:
> From: Zhang Yi <[e-mail]>
> 
> Add a private parameter to iomap_ioend structure, letting filesystems
> can pass something they needed from .prepare_ioend() to IO end.

On it's own this looks fine.  Note that I have a series that I probably
should send out ASAP:

   http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/iomap-map-multiple-blocks

that makes each ioend only have the embdeed bio, and bi_private in that
is unused, so you could just use that if we go down that route.

Zhang Yi Nov. 24, 2023, 1:36 a.m. UTC | #2

On 2023/11/23 23:36, Christoph Hellwig wrote:
> On Thu, Nov 23, 2023 at 08:51:13PM +0800, Zhang Yi wrote:
>> From: Zhang Yi <[e-mail]>
>>
>> Add a private parameter to iomap_ioend structure, letting filesystems
>> can pass something they needed from .prepare_ioend() to IO end.
> 
> On it's own this looks fine.  Note that I have a series that I probably
> should send out ASAP:
> 
>    http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/iomap-map-multiple-blocks
> 
> that makes each ioend only have the embdeed bio, and bi_private in that
> is unused, so you could just use that if we go down that route.
> 

Thanks for this improvement, I will analyze the changes of this series
in depth.

Thanks,
Yi.

Patch

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 2bc0aa23fde3..fd4d43bafd1b 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1676,6 +1676,7 @@  iomap_alloc_ioend(struct inode *inode, struct iomap_writepage_ctx *wpc,
 	ioend->io_offset = offset;
 	ioend->io_bio = bio;
 	ioend->io_sector = sector;
+	ioend->io_private = NULL;
 	return ioend;
 }
 
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 96dd0acbba44..8b3296a5474d 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -300,6 +300,7 @@  struct iomap_ioend {
 	sector_t		io_sector;	/* start sector of ioend */
 	struct bio		*io_bio;	/* bio being built */
 	struct bio		io_inline_bio;	/* MUST BE LAST! */
+	void			*io_private;	/* fs private pointer */
 };
 
 struct iomap_writeback_ops {