From: Xiubo Li <xiubli@xxxxxxxxxx>
For write when trying to get the Fwb caps we need to keep waiting
on transition from WRBUFFER|WR -> WR to avoid a new WR sync write
from going before a prior buffered writeback happens.
Whild for read there is not need to wait on transition from
RDCACHE|RD -> RD, and we can just exclude the revoking caps and
force to sync read.
Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx>
---
fs/ceph/caps.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 139d21b8fb49..d5fc9b1be7c3 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2811,13 +2811,17 @@ static int try_get_cap_refs(struct inode *inode, int need, int want,
* on transition from wanted -> needed caps. This is needed
* for WRBUFFER|WR -> WR to avoid a new WR sync write from
* going before a prior buffered writeback happens.
+ *
+ * For RDCACHE|RD -> RD, there is not need to wait and we can
+ * just exclude the revoking caps and force to sync read.
*/
int not = want & ~(have & need);
int revoking = implemented & ~have;
+ int exclude = revoking & not;
dout("get_cap_refs %p have %s but not %s (revoking %s)\n",
inode, ceph_cap_string(have), ceph_cap_string(not),
ceph_cap_string(revoking));
- if ((revoking & not) == 0) {
+ if (!exclude || !(exclude & CEPH_CAP_FILE_BUFFER)) {
if (!snap_rwsem_locked &&
!ci->i_head_snapc &&
(need & CEPH_CAP_FILE_WR)) {
@@ -2839,7 +2843,7 @@ static int try_get_cap_refs(struct inode *inode, int need, int want,
snap_rwsem_locked = true;
}
if ((have & want) == want)
- *got = need | want;
+ *got = need | (want & ~exclude);
else
*got = need;
ceph_take_cap_refs(ci, *got, true);
--
2.36.0.rc1
