[PATCH v2 3/7] iomap: Lift blocksize restriction on atomic writes

John Garry
2024-12-10T12:58:28Z

From: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>

Filesystems like ext4 can submit writes in multiples of blocksizes.
But we still can't allow the writes to be split. Hence let's check if
the iomap_length() is same as iter->len or not.

It is the role of the FS to ensure that a single mapping may be created
for an atomic write. The FS will also continue to check size and alignment
legality.

Signed-off-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
jpg: Tweak commit message
Signed-off-by: John Garry <john.g.garry@oracle.com>
---
fs/iomap/direct-io.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 18c888f0c11f..6510bb5d5a6f 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -314,7 +314,7 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter,
size_t copied = 0;
size_t orig_count;

- if (atomic && length != fs_block_size)
+ if (atomic && length != iter->len)
return -EINVAL;

if ((pos | length) & (bdev_logical_block_size(iomap->bdev) - 1) ||
--
2.31.1