xfs: get root inode correctly at bulkstat

mainline inclusion
from mainline-v6.2-rc4
commit 817644fa
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4KIAO
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=817644fa4525258992f17fecf4f1d6cdd2e1b731

--------------------------------

The root inode number should be set to `breq->startino` for getting stat
information of the root when XFS_BULK_IREQ_SPECIAL_ROOT is used.
Otherwise, the inode search is started from 1
(XFS_BULK_IREQ_SPECIAL_ROOT) and the inode with the lowest number in a
filesystem is returned.

Fixes: bf3cb394 ("xfs: allow single bulkstat of special inodes")
Signed-off-by: NHironori Shiina <shiina.hironori@fujitsu.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: Nyangerkun <yangerkun@huaweicloud.com>
Reviewed-by: NZhang Yi <yi.zhang@huawei.com>
Signed-off-by: NJialin Zhang <zhangjialin11@huawei.com>

fs/xfs/xfs_ioctl.c

@@ -830,7 +830,7 @@ xfs_bulkstat_fmt(
 static int
 xfs_bulk_ireq_setup(
 	struct xfs_mount	*mp,
-	struct xfs_bulk_ireq	*hdr,
+	const struct xfs_bulk_ireq *hdr,
 	struct xfs_ibulk	*breq,
 	void __user		*ubuffer)
 {
@@ -856,7 +856,7 @@ xfs_bulk_ireq_setup(
 
 		switch (hdr->ino) {
 		case XFS_BULK_IREQ_SPECIAL_ROOT:
-			hdr->ino = mp->m_sb.sb_rootino;
+			breq->startino = mp->m_sb.sb_rootino;
 			break;
 		default:
 			return -EINVAL;