fs: move the bdex_statx call to vfs_getattr_nosec

Currently bdex_statx is only called from the very high-level
vfs_statx_path function, and thus bypassing it for in-kernel calls
to vfs_getattr or vfs_getattr_nosec.

This breaks querying the block ѕize of the underlying device in the
loop driver and also is a pitfall for any other new kernel caller.

Move the call into the lowest level helper to ensure all callers get
the right results.

Fixes: 2d985f8c6b91 ("vfs: support STATX_DIOALIGN on block devices")
Fixes: f4774e92aab8 ("loop: take the file system minimum dio alignment into account")
Reported-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/20250417064042.712140-1-hch@lst.de
Signed-off-by: Christian Brauner <brauner@kernel.org>

1 files changed, 18 insertions, 14 deletions

diff --git a/fs/stat.c b/fs/stat.c
index f13308bfdc98..3d9222807214 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -204,12 +204,25 @@ int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
 				  STATX_ATTR_DAX);
 
 	idmap = mnt_idmap(path->mnt);
-	if (inode->i_op->getattr)
-		return inode->i_op->getattr(idmap, path, stat,
-					    request_mask,
-					    query_flags);
+	if (inode->i_op->getattr) {
+		int ret;
+
+		ret = inode->i_op->getattr(idmap, path, stat, request_mask,
+				query_flags);
+		if (ret)
+			return ret;
+	} else {
+		generic_fillattr(idmap, request_mask, inode, stat);
+	}
+
+	/*
+	 * If this is a block device inode, override the filesystem attributes
+	 * with the block device specific parameters that need to be obtained
+	 * from the bdev backing inode.
+	 */
+	if (S_ISBLK(stat->mode))
+		bdev_statx(path, stat, request_mask);
 
-	generic_fillattr(idmap, request_mask, inode, stat);
 	return 0;
 }
 EXPORT_SYMBOL(vfs_getattr_nosec);
@@ -295,15 +308,6 @@ static int vfs_statx_path(struct path *path, int flags, struct kstat *stat,
 	if (path_mounted(path))
 		stat->attributes |= STATX_ATTR_MOUNT_ROOT;
 	stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;
-
-	/*
-	 * If this is a block device inode, override the filesystem
-	 * attributes with the block device specific parameters that need to be
-	 * obtained from the bdev backing inode.
-	 */
-	if (S_ISBLK(stat->mode))
-		bdev_statx(path, stat, request_mask);
-
 	return 0;
 }