From 9c421ef3f6b30ab912eaaa3c3d20cfb921fd8c8f Mon Sep 17 00:00:00 2001
From: Hongbo Li <lihongbo22@huawei.com>
Date: Thu, 18 Jul 2024 16:32:43 +0800
Subject: [PATCH] erofs: support STATX_DIOALIGN
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 <lihongbo22@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240718083243.2485437-1-hsiangkao@linux.alibaba.com
---
fs/erofs/inode.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index 5f6439a63af79..43c09aae2afcd 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -334,14 +334,29 @@ int erofs_getattr(struct mnt_idmap *idmap, const struct path *path,
unsigned int query_flags)
{
struct inode *const inode = d_inode(path->dentry);
+ bool compressed =
+ erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout);
- if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout))
+ if (compressed)
stat->attributes |= STATX_ATTR_COMPRESSED;
-
stat->attributes |= STATX_ATTR_IMMUTABLE;
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
+ * compressed files, 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) && !compressed) {
+ stat->dio_mem_align =
+ bdev_logical_block_size(inode->i_sb->s_bdev);
+ stat->dio_offset_align = stat->dio_mem_align;
+ }
+ }
generic_fillattr(idmap, request_mask, inode, stat);
return 0;
}
--
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