Hi,
On 2024/7/16 20:45, Hongbo Li wrote:
Add support for STATX_DIOALIGN to erofs, so that direct I/O
alignment restrictions are exposed to userspace in a generic
way.
[Before]
```
./statx_test /mnt/erofs/testfile
statx(/mnt/erofs/testfile) = 0
dio mem align:0
dio offset align:0
```
[After]
```
./statx_test /mnt/erofs/testfile
statx(/mnt/erofs/testfile) = 0
dio mem align:512
dio offset align:512
```
Signed-off-by: Hongbo Li <lihongb...@huawei.com>
---
fs/erofs/inode.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index 5f6439a63af7..9325a6f0058a 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -342,6 +342,25 @@ int erofs_getattr(struct mnt_idmap *idmap, const struct
path *path,
stat->attributes_mask |= (STATX_ATTR_COMPRESSED |
STATX_ATTR_IMMUTABLE);
+ /*
+ * Return the DIO alignment restrictions if requested.
+ *
+ * In erofs, STATX_DIOALIGN is not supported in ondemand mode and
+ * the compressed file, so in these cases we report no DIO support.
+ */
+ if ((request_mask & STATX_DIOALIGN) && S_ISREG(inode->i_mode)) {
+ stat->result_mask |= STATX_DIOALIGN;
+ if (!erofs_is_fscache_mode(inode->i_sb) &&
+
!erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout)) {
+ struct block_device *bdev = inode->i_sb->s_bdev;
+ unsigned int bsize = (bdev) ?
bdev_logical_block_size(bdev) :
+ i_blocksize(inode);
I guess in this way you could always use
stat->dio_mem_align = bdev_logical_block_size(bdev);
stat->dio_offset_align = stat->dio_mem_align;
? since bdev won't be NULL.
Otherwise it looks good to me.
Thanks,
Gao Xiang
