From: Kotresh HR <khiremat@redhat.com>
Date: Wed, 10 Nov 2021 23:30:21 +0530
Subject: ceph: Fix incorrect statfs report for small quota
Git-commit: 8e55ba8caae5cd380b1c9c81a426602a667e110e
Patch-mainline: v5.17-rc1
References: jsc#SES-1880
Problem:
The statfs reports incorrect free/available space for quota less then
CEPH_BLOCK size (4M).
Solution:
For quota less than CEPH_BLOCK size, smaller block size of 4K is used.
But if quota is less than 4K, it is decided to go with binary use/free
of 4K block. For quota size less than 4K size, report the
total=used=4K,free=0 when quota is full and total=free=4K,used=0
otherwise.
Signed-off-by: Kotresh HR <khiremat@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Acked-by: Luis Henriques <lhenriques@suse.com>
---
fs/ceph/quota.c | 14 ++++++++++++++
fs/ceph/super.h | 1 +
2 files changed, 15 insertions(+)
diff --git a/fs/ceph/quota.c b/fs/ceph/quota.c
index 620c691af40e..24ae13ea2241 100644
--- a/fs/ceph/quota.c
+++ b/fs/ceph/quota.c
@@ -494,10 +494,24 @@ bool ceph_quota_update_statfs(struct ceph_fs_client *fsc, struct kstatfs *buf)
if (ci->i_max_bytes) {
total = ci->i_max_bytes >> CEPH_BLOCK_SHIFT;
used = ci->i_rbytes >> CEPH_BLOCK_SHIFT;
+ /* For quota size less than 4MB, use 4KB block size */
+ if (!total) {
+ total = ci->i_max_bytes >> CEPH_4K_BLOCK_SHIFT;
+ used = ci->i_rbytes >> CEPH_4K_BLOCK_SHIFT;
+ buf->f_frsize = 1 << CEPH_4K_BLOCK_SHIFT;
+ }
/* It is possible for a quota to be exceeded.
* Report 'zero' in that case
*/
free = total > used ? total - used : 0;
+ /* For quota size less than 4KB, report the
+ * total=used=4KB,free=0 when quota is full
+ * and total=free=4KB, used=0 otherwise */
+ if (!total) {
+ total = 1;
+ free = ci->i_max_bytes > ci->i_rbytes ? 1 : 0;
+ buf->f_frsize = 1 << CEPH_4K_BLOCK_SHIFT;
+ }
}
spin_unlock(&ci->i_ceph_lock);
if (total) {
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index ec6b221e5b62..533189b537b2 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -32,6 +32,7 @@
* large volume sizes on 32-bit machines. */
#define CEPH_BLOCK_SHIFT 22 /* 4 MB */
#define CEPH_BLOCK (1 << CEPH_BLOCK_SHIFT)
+#define CEPH_4K_BLOCK_SHIFT 12 /* 4 KB */
#define CEPH_MOUNT_OPT_CLEANRECOVER (1<<1) /* auto reonnect (clean mode) after blocklisted */
#define CEPH_MOUNT_OPT_DIRSTAT (1<<4) /* `cat dirname` for stats */