Use iomap in buffer_head compat mode to write to block devices.
Signed-off-by: Christoph Hellwig <[email protected]>
---
block/Kconfig | 1 +
block/fops.c | 31 +++++++++++++++++++++++++++++--
2 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/block/Kconfig b/block/Kconfig
index 86122e459fe046..1a13ef0b1ca10c 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -5,6 +5,7 @@
menuconfig BLOCK
bool "Enable the block layer" if EXPERT
default y
+ select FS_IOMAP
select SBITMAP
help
Provide block layer support for the kernel.
diff --git a/block/fops.c b/block/fops.c
index 0c37c35003c3b7..31d356c83f27a3 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -15,6 +15,7 @@
#include <linux/falloc.h>
#include <linux/suspend.h>
#include <linux/fs.h>
+#include <linux/iomap.h>
#include <linux/module.h>
#include "blk.h"
@@ -386,6 +387,27 @@ static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
return __blkdev_direct_IO(iocb, iter, bio_max_segs(nr_pages));
}
+static int blkdev_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
+ unsigned int flags, struct iomap *iomap, struct iomap *srcmap)
+{
+ struct block_device *bdev = I_BDEV(inode);
+ loff_t isize = i_size_read(inode);
+
+ iomap->bdev = bdev;
+ iomap->offset = ALIGN_DOWN(offset, bdev_logical_block_size(bdev));
+ if (WARN_ON_ONCE(iomap->offset >= isize))
+ return -EIO;
+ iomap->type = IOMAP_MAPPED;
+ iomap->addr = iomap->offset;
+ iomap->length = isize - iomap->offset;
+ iomap->flags |= IOMAP_F_BUFFER_HEAD;
+ return 0;
+}
+
+static const struct iomap_ops blkdev_iomap_ops = {
+ .iomap_begin = blkdev_iomap_begin,
+};
+
static int blkdev_writepage(struct page *page, struct writeback_control *wbc)
{
return block_write_full_page(page, blkdev_get_block, wbc);
@@ -555,6 +577,11 @@ blkdev_direct_write(struct kiocb *iocb, struct iov_iter *from)
return written;
}
+static ssize_t blkdev_buffered_write(struct kiocb *iocb, struct iov_iter *from)
+{
+ return iomap_file_buffered_write(iocb, from, &blkdev_iomap_ops);
+}
+
/*
* Write data to the block device. Only intended for the block device itself
* and the raw driver which basically is a fake block device.
@@ -604,9 +631,9 @@ static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
ret = blkdev_direct_write(iocb, from);
if (ret >= 0 && iov_iter_count(from))
ret = direct_write_fallback(iocb, from, ret,
- generic_perform_write(iocb, from));
+ blkdev_buffered_write(iocb, from));
} else {
- ret = generic_perform_write(iocb, from);
+ ret = blkdev_buffered_write(iocb, from);
}
if (ret > 0)
--
2.39.2
On 7/20/23 16:04, Christoph Hellwig wrote:
> Use iomap in buffer_head compat mode to write to block devices.
>
> Signed-off-by: Christoph Hellwig <[email protected]>
> ---
> block/Kconfig | 1 +
> block/fops.c | 31 +++++++++++++++++++++++++++++--
> 2 files changed, 30 insertions(+), 2 deletions(-)
>
Reviewed-by: Hannes Reinecke <[email protected]>
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
[email protected] +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman
On Thu, Jul 20, 2023 at 04:04:51PM +0200, Christoph Hellwig wrote:
> Use iomap in buffer_head compat mode to write to block devices.
>
> Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Luis Chamberlain <[email protected]>
Luis
On Thu, Jul 20, 2023 at 04:04:51PM +0200, Christoph Hellwig wrote:
> Use iomap in buffer_head compat mode to write to block devices.
>
> Signed-off-by: Christoph Hellwig <[email protected]>
Looks good,
Reviewed-by: Pankaj Raghav <[email protected]>