Commit ae2dffa3 authored by Kirill Tkhai's avatar Kirill Tkhai Committed by Miklos Szeredi
Browse files

fuse: introduce fc->bg_lock



To reduce contention of fc->lock, this patch introduces bg_lock for
protection of fields related to background queue. These are:
max_background, congestion_threshold, num_background, active_background,
bg_queue and blocked.

This allows next patch to make async reads not requiring fc->lock, so async
reads and writes will have better performance executed in parallel.
Signed-off-by: default avatarKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 2b30a533
......@@ -125,12 +125,12 @@ static ssize_t fuse_conn_max_background_write(struct file *file,
if (ret > 0) {
struct fuse_conn *fc = fuse_ctl_file_conn_get(file);
if (fc) {
spin_lock(&fc->lock);
spin_lock(&fc->bg_lock);
fc->max_background = val;
fc->blocked = fc->num_background >= fc->max_background;
if (!fc->blocked)
wake_up(&fc->blocked_waitq);
spin_unlock(&fc->lock);
spin_unlock(&fc->bg_lock);
fuse_conn_put(fc);
}
}
......@@ -171,7 +171,7 @@ static ssize_t fuse_conn_congestion_threshold_write(struct file *file,
if (!fc)
goto out;
spin_lock(&fc->lock);
spin_lock(&fc->bg_lock);
fc->congestion_threshold = val;
if (fc->sb) {
if (fc->num_background < fc->congestion_threshold) {
......@@ -182,7 +182,7 @@ static ssize_t fuse_conn_congestion_threshold_write(struct file *file,
set_bdi_congested(fc->sb->s_bdi, BLK_RW_ASYNC);
}
}
spin_unlock(&fc->lock);
spin_unlock(&fc->bg_lock);
fuse_conn_put(fc);
out:
return ret;
......
......@@ -287,10 +287,10 @@ void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
* We get here in the unlikely case that a background
* request was allocated but not sent
*/
spin_lock(&fc->lock);
spin_lock(&fc->bg_lock);
if (!fc->blocked)
wake_up(&fc->blocked_waitq);
spin_unlock(&fc->lock);
spin_unlock(&fc->bg_lock);
}
if (test_bit(FR_WAITING, &req->flags)) {
......@@ -390,7 +390,7 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req)
WARN_ON(test_bit(FR_PENDING, &req->flags));
WARN_ON(test_bit(FR_SENT, &req->flags));
if (test_bit(FR_BACKGROUND, &req->flags)) {
spin_lock(&fc->lock);
spin_lock(&fc->bg_lock);
clear_bit(FR_BACKGROUND, &req->flags);
if (fc->num_background == fc->max_background) {
fc->blocked = 0;
......@@ -413,7 +413,7 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req)
fc->num_background--;
fc->active_background--;
flush_bg_queue(fc);
spin_unlock(&fc->lock);
spin_unlock(&fc->bg_lock);
}
wake_up(&req->waitq);
if (req->end)
......@@ -586,8 +586,8 @@ ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args)
*
* fc->connected must have been checked previously
*/
void fuse_request_send_background_locked(struct fuse_conn *fc,
struct fuse_req *req)
void fuse_request_send_background_nocheck(struct fuse_conn *fc,
struct fuse_req *req)
{
BUG_ON(!test_bit(FR_BACKGROUND, &req->flags));
if (!test_bit(FR_WAITING, &req->flags)) {
......@@ -595,6 +595,7 @@ void fuse_request_send_background_locked(struct fuse_conn *fc,
atomic_inc(&fc->num_waiting);
}
__set_bit(FR_ISREPLY, &req->flags);
spin_lock(&fc->bg_lock);
fc->num_background++;
if (fc->num_background == fc->max_background)
fc->blocked = 1;
......@@ -604,6 +605,7 @@ void fuse_request_send_background_locked(struct fuse_conn *fc,
}
list_add_tail(&req->list, &fc->bg_queue);
flush_bg_queue(fc);
spin_unlock(&fc->bg_lock);
}
void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req)
......@@ -611,7 +613,7 @@ void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req)
BUG_ON(!req->end);
spin_lock(&fc->lock);
if (fc->connected) {
fuse_request_send_background_locked(fc, req);
fuse_request_send_background_nocheck(fc, req);
spin_unlock(&fc->lock);
} else {
spin_unlock(&fc->lock);
......@@ -2118,7 +2120,6 @@ void fuse_abort_conn(struct fuse_conn *fc, bool is_abort)
LIST_HEAD(to_end);
fc->connected = 0;
fc->blocked = 0;
fc->aborted = is_abort;
fuse_set_initialized(fc);
list_for_each_entry(fud, &fc->devices, entry) {
......@@ -2140,8 +2141,11 @@ void fuse_abort_conn(struct fuse_conn *fc, bool is_abort)
list_splice_tail_init(&fpq->processing, &to_end);
spin_unlock(&fpq->lock);
}
spin_lock(&fc->bg_lock);
fc->blocked = 0;
fc->max_background = UINT_MAX;
flush_bg_queue(fc);
spin_unlock(&fc->bg_lock);
spin_lock(&fiq->waitq.lock);
fiq->connected = 0;
......
......@@ -1502,7 +1502,7 @@ __acquires(fc->lock)
req->in.args[1].size = inarg->size;
fi->writectr++;
fuse_request_send_background_locked(fc, req);
fuse_request_send_background_nocheck(fc, req);
return;
out_free:
......
......@@ -500,6 +500,10 @@ struct fuse_conn {
/** The list of background requests set aside for later queuing */
struct list_head bg_queue;
/** Protects: max_background, congestion_threshold, num_background,
* active_background, bg_queue, blocked */
spinlock_t bg_lock;
/** Flag indicating that INIT reply has been received. Allocating
* any fuse request will be suspended until the flag is set */
int initialized;
......@@ -860,8 +864,8 @@ ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args);
*/
void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
void fuse_request_send_background_locked(struct fuse_conn *fc,
struct fuse_req *req);
void fuse_request_send_background_nocheck(struct fuse_conn *fc,
struct fuse_req *req);
/* Abort all requests */
void fuse_abort_conn(struct fuse_conn *fc, bool is_abort);
......
......@@ -605,6 +605,7 @@ void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns)
{
memset(fc, 0, sizeof(*fc));
spin_lock_init(&fc->lock);
spin_lock_init(&fc->bg_lock);
init_rwsem(&fc->killsb);
refcount_set(&fc->count, 1);
atomic_set(&fc->dev_count, 1);
......@@ -852,6 +853,7 @@ static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
sanitize_global_limit(&max_user_bgreq);
sanitize_global_limit(&max_user_congthresh);
spin_lock(&fc->bg_lock);
if (arg->max_background) {
fc->max_background = arg->max_background;
......@@ -865,6 +867,7 @@ static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
fc->congestion_threshold > max_user_congthresh)
fc->congestion_threshold = max_user_congthresh;
}
spin_unlock(&fc->bg_lock);
}
static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
......
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