Validate that an atomic write adheres to length/offset rules. Currently
we can only write a single FS block.
For an IOCB with IOCB_ATOMIC set to get as far as xfs_file_dio_write(),
FMODE_CAN_ATOMIC_WRITE will need to be set for the file; for this,
ATOMICWRITES flags would also need to be set for the inode.
Signed-off-by: John Garry <john.g.garry@xxxxxxxxxx>
---
fs/xfs/xfs_file.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 412b1d71b52b..fa6a44b88ecc 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -688,6 +688,13 @@ xfs_file_dio_write(
struct xfs_buftarg *target = xfs_inode_buftarg(ip);
size_t count = iov_iter_count(from);
+ if (iocb->ki_flags & IOCB_ATOMIC) {
+ if (count != ip->i_mount->m_sb.sb_blocksize)
+ return -EINVAL;
+ if (!generic_atomic_write_valid(iocb, from))
+ return -EINVAL;
+ }
+
/* direct I/O must be aligned to device logical sector size */
if ((iocb->ki_pos | count) & target->bt_logical_sectormask)
return -EINVAL;
--
2.31.1
