This is a note to let you know that I've just added the patch titled
cachefiles: narrow the scope of triggering EPOLLIN events in ondemand mode
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cachefiles-narrow-the-scope-of-triggering-epollin-ev.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 4c716f8575302f00d82e77b23cfb65120313a765
Author: Jia Zhu <zhujia.zj@xxxxxxxxxxxxx>
Date: Mon Nov 20 12:14:21 2023 +0800
cachefiles: narrow the scope of triggering EPOLLIN events in ondemand mode
[ Upstream commit b817e22b2e91257ace32a6768c3c003faeaa1c5c ]
Don't trigger EPOLLIN when there are only reopening read requests in
xarray.
Suggested-by: Xin Yin <yinxin.x@xxxxxxxxxxxxx>
Signed-off-by: Jia Zhu <zhujia.zj@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20231120041422.75170-5-zhujia.zj@xxxxxxxxxxxxx
Reviewed-by: Jingbo Xu <jefflexu@xxxxxxxxxxxxxxxxx>
Reviewed-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Stable-dep-of: 12e009d60852 ("cachefiles: wait for ondemand_object_worker to finish when dropping object")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c
index b9945e4f697be..06cdf1a8a16f6 100644
--- a/fs/cachefiles/daemon.c
+++ b/fs/cachefiles/daemon.c
@@ -357,14 +357,24 @@ static __poll_t cachefiles_daemon_poll(struct file *file,
struct poll_table_struct *poll)
{
struct cachefiles_cache *cache = file->private_data;
+ XA_STATE(xas, &cache->reqs, 0);
+ struct cachefiles_req *req;
__poll_t mask;
poll_wait(file, &cache->daemon_pollwq, poll);
mask = 0;
if (cachefiles_in_ondemand_mode(cache)) {
- if (!xa_empty(&cache->reqs))
- mask |= EPOLLIN;
+ if (!xa_empty(&cache->reqs)) {
+ rcu_read_lock();
+ xas_for_each_marked(&xas, req, ULONG_MAX, CACHEFILES_REQ_NEW) {
+ if (!cachefiles_ondemand_is_reopening_read(req)) {
+ mask |= EPOLLIN;
+ break;
+ }
+ }
+ rcu_read_unlock();
+ }
} else {
if (test_bit(CACHEFILES_STATE_CHANGED, &cache->flags))
mask |= EPOLLIN;
diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index 3eea52462fc87..e0eac16e4741c 100644
--- a/fs/cachefiles/internal.h
+++ b/fs/cachefiles/internal.h
@@ -335,6 +335,13 @@ cachefiles_ondemand_set_object_##_state(struct cachefiles_object *object) \
CACHEFILES_OBJECT_STATE_FUNCS(open, OPEN);
CACHEFILES_OBJECT_STATE_FUNCS(close, CLOSE);
CACHEFILES_OBJECT_STATE_FUNCS(reopening, REOPENING);
+
+static inline bool cachefiles_ondemand_is_reopening_read(struct cachefiles_req *req)
+{
+ return cachefiles_ondemand_object_is_reopening(req->object) &&
+ req->msg.opcode == CACHEFILES_OP_READ;
+}
+
#else
static inline ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
char __user *_buffer, size_t buflen)
@@ -365,6 +372,11 @@ static inline int cachefiles_ondemand_init_obj_info(struct cachefiles_object *ob
static inline void cachefiles_ondemand_deinit_obj_info(struct cachefiles_object *obj)
{
}
+
+static inline bool cachefiles_ondemand_is_reopening_read(struct cachefiles_req *req)
+{
+ return false;
+}
#endif
/*
