[PATCH] block: clean up the check in blkdev_iomap_begin()

[PATCH] block: clean up the check in blkdev_iomap_begin()

[linan666]

From: Li Nan <linan122@huawei.com>

It is odd to check the offset amidst a series of assignments. Moving this
check to the beginning of the function makes the code look better.

Signed-off-by: Li Nan <linan122@huawei.com>
---
 block/fops.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/block/fops.c b/block/fops.c
index 376265935714..bc5ad3e6197f 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -383,10 +383,11 @@ static int blkdev_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
 	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 (offset >= isize)
 		return -EIO;
+
+	iomap->bdev = bdev;
+	iomap->offset = ALIGN_DOWN(offset, bdev_logical_block_size(bdev));
 	iomap->type = IOMAP_MAPPED;
 	iomap->addr = iomap->offset;
 	iomap->length = isize - iomap->offset;
-- 
2.39.2

Re: [PATCH] block: clean up the check in blkdev_iomap_begin()

[Chaitanya Kulkarni]

On 6/25/24 04:55, linan666@huaweicloud.com wrote:
> From: Li Nan<linan122@huawei.com>
>
> It is odd to check the offset amidst a series of assignments. Moving this
> check to the beginning of the function makes the code look better.
>
> Signed-off-by: Li Nan<linan122@huawei.com>

it is always better to wait for assignments after all the error checks.

I believe you have verified all the callers and make sure none of the
callers rely on these assignments when this function returns -EIO and
this change will not result in change of behavior, if that is the
case :-

Looks good.

Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

-ck

Re: [PATCH] block: clean up the check in blkdev_iomap_begin()

[Christoph Hellwig]

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH] block: clean up the check in blkdev_iomap_begin()

[Jens Axboe]

On Tue, 25 Jun 2024 19:55:17 +0800, linan666@huaweicloud.com wrote:
> It is odd to check the offset amidst a series of assignments. Moving this
> check to the beginning of the function makes the code look better.
> 
> 

Applied, thanks!

[1/1] block: clean up the check in blkdev_iomap_begin()
      commit: e269537e491da6336776b5548a3c73f62273aa15

Best regards,
-- 
Jens Axboe