* [PATCH] block: Don't allow an atomic write be truncated in blkdev_write_iter()
@ 2024-11-27 9:23 John Garry
2024-11-27 9:31 ` Christoph Hellwig
2024-11-27 22:05 ` Jens Axboe
0 siblings, 2 replies; 3+ messages in thread
From: John Garry @ 2024-11-27 9:23 UTC (permalink / raw)
To: axboe; +Cc: linux-block, hare, hch, martin.petersen, John Garry
A write which goes past the end of the bdev in blkdev_write_iter() will
be truncated. Truncating cannot tolerated for an atomic write, so error
that condition.
Fixes: caf336f81b3a ("block: Add fops atomic write support")
Signed-off-by: John Garry <john.g.garry@oracle.com>
diff --git a/block/fops.c b/block/fops.c
index 2d01c9007681..13a67940d040 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -677,6 +677,7 @@ static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
struct file *file = iocb->ki_filp;
struct inode *bd_inode = bdev_file_inode(file);
struct block_device *bdev = I_BDEV(bd_inode);
+ bool atomic = iocb->ki_flags & IOCB_ATOMIC;
loff_t size = bdev_nr_bytes(bdev);
size_t shorted = 0;
ssize_t ret;
@@ -696,7 +697,7 @@ static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT)
return -EOPNOTSUPP;
- if (iocb->ki_flags & IOCB_ATOMIC) {
+ if (atomic) {
ret = generic_atomic_write_valid(iocb, from);
if (ret)
return ret;
@@ -704,6 +705,8 @@ static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
size -= iocb->ki_pos;
if (iov_iter_count(from) > size) {
+ if (atomic)
+ return -EINVAL;
shorted = iov_iter_count(from) - size;
iov_iter_truncate(from, size);
}
--
2.31.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] block: Don't allow an atomic write be truncated in blkdev_write_iter()
2024-11-27 9:23 [PATCH] block: Don't allow an atomic write be truncated in blkdev_write_iter() John Garry
@ 2024-11-27 9:31 ` Christoph Hellwig
2024-11-27 22:05 ` Jens Axboe
1 sibling, 0 replies; 3+ messages in thread
From: Christoph Hellwig @ 2024-11-27 9:31 UTC (permalink / raw)
To: John Garry; +Cc: axboe, linux-block, hare, hch, martin.petersen
Looks good:
Reviewed-by: Christoph Hellwig <hch@lst.de>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] block: Don't allow an atomic write be truncated in blkdev_write_iter()
2024-11-27 9:23 [PATCH] block: Don't allow an atomic write be truncated in blkdev_write_iter() John Garry
2024-11-27 9:31 ` Christoph Hellwig
@ 2024-11-27 22:05 ` Jens Axboe
1 sibling, 0 replies; 3+ messages in thread
From: Jens Axboe @ 2024-11-27 22:05 UTC (permalink / raw)
To: John Garry; +Cc: linux-block, hare, hch, martin.petersen
On Wed, 27 Nov 2024 09:23:18 +0000, John Garry wrote:
> A write which goes past the end of the bdev in blkdev_write_iter() will
> be truncated. Truncating cannot tolerated for an atomic write, so error
> that condition.
>
>
Applied, thanks!
[1/1] block: Don't allow an atomic write be truncated in blkdev_write_iter()
commit: 2cbd51f1f8739fd2fdf4bae1386bcf75ce0176ba
Best regards,
--
Jens Axboe
^ permalink raw reply [flat|nested] 3+ messages in thread
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2024-11-27 9:23 [PATCH] block: Don't allow an atomic write be truncated in blkdev_write_iter() John Garry
2024-11-27 9:31 ` Christoph Hellwig
2024-11-27 22:05 ` Jens Axboe
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