xfs: flush inode inactivation work when compiling usage statistics

mainline-inclusion
from mainline-v5.14-rc4
commit 01e8f379
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=01e8f379a4895a9a173391408db4fb49ec91e148

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

mainline-inclusion
from mainline-v5.14-rc4
commit 01e8f379
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=01e8f379a4895a9a173391408db4fb49ec91e148

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Users have come to expect that the space accounting information in
statfs and getquota reports are fairly accurate.  Now that we inactivate
inodes from a background queue, these numbers can be thrown off by
whatever resources are singly-owned by the inodes in the queue.  Flush
the pending inactivations when userspace asks for a space usage report.
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NLihong Kou <koulihong@huawei.com>
Reviewed-by: NZhang Yi <yi.zhang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

fs/xfs/xfs_qm_syscalls.c

@@ -481,6 +481,10 @@ xfs_qm_scall_getquota(
 	struct xfs_dquot	*dqp;
 	int			error;
 
+	/* Flush inodegc work at the start of a quota reporting scan. */
+	if (id == 0)
+		xfs_inodegc_flush(mp);
+
 	/*
 	 * Try to get the dquot. We don't want it allocated on disk, so don't
 	 * set doalloc. If it doesn't exist, we'll get ENOENT back.
@@ -519,6 +523,10 @@ xfs_qm_scall_getquota_next(
 	struct xfs_dquot	*dqp;
 	int			error;
 
+	/* Flush inodegc work at the start of a quota reporting scan. */
+	if (*id == 0)
+		xfs_inodegc_flush(mp);
+
 	error = xfs_qm_dqget_next(mp, *id, type, &dqp);
 	if (error)
 		return error;

fs/xfs/xfs_super.c

@@ -791,6 +791,9 @@ xfs_fs_statfs(
 	xfs_extlen_t		lsize;
 	int64_t			ffree;
 
+	/* Wait for whatever inactivations are in progress. */
+	xfs_inodegc_flush(mp);
+
 	statp->f_type = XFS_SUPER_MAGIC;
 	statp->f_namelen = MAXNAMELEN - 1;