[Devel] [PATCH vz7 23/46] fuse: iqueue locking
Maxim Patlasov
mpatlasov at virtuozzo.com
Fri Mar 24 19:21:47 PDT 2017
Backport from ml:
commit 4ce6081260ea4c1b5bfa8ecca5cbb93eea279ad4
Author: Miklos Szeredi <mszeredi at suse.cz>
Date: Wed Jul 1 16:26:02 2015 +0200
fuse: iqueue locking
Use fiq->waitq.lock for protecting members of struct fuse_iqueue and
FR_PENDING request flag, previously protected by fc->lock.
Following patches will remove fc->lock protection from these members.
Signed-off-by: Miklos Szeredi <mszeredi at suse.cz>
Reviewed-by: Ashish Samant <ashish.samant at oracle.com>
Signed-off-by: Maxim Patlasov <mpatlasov at virtuozzo.com>
---
fs/fuse/dev.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 46 insertions(+), 6 deletions(-)
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 1349fb3..de28d86 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -311,7 +311,7 @@ static void queue_request(struct fuse_iqueue *fiq, struct fuse_req *req)
req->in.h.len = sizeof(struct fuse_in_header) +
len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
list_add_tail(&req->list, &fiq->pending);
- wake_up(&fiq->waitq);
+ wake_up_locked(&fiq->waitq);
kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
}
@@ -324,14 +324,16 @@ void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
forget->forget_one.nlookup = nlookup;
spin_lock(&fc->lock);
+ spin_lock(&fiq->waitq.lock);
if (fiq->connected) {
fiq->forget_list_tail->next = forget;
fiq->forget_list_tail = forget;
- wake_up(&fiq->waitq);
+ wake_up_locked(&fiq->waitq);
kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
} else {
kfree(forget);
}
+ spin_unlock(&fiq->waitq.lock);
spin_unlock(&fc->lock);
}
@@ -345,8 +347,10 @@ static void flush_bg_queue(struct fuse_conn *fc)
req = list_entry(fc->bg_queue.next, struct fuse_req, list);
list_del(&req->list);
fc->active_background++;
+ spin_lock(&fiq->waitq.lock);
req->in.h.unique = fuse_get_unique(fiq);
queue_request(fiq, req);
+ spin_unlock(&fiq->waitq.lock);
}
}
@@ -363,10 +367,13 @@ static void flush_bg_queue(struct fuse_conn *fc)
static void request_end(struct fuse_conn *fc, struct fuse_req *req)
__releases(fc->lock)
{
+ struct fuse_iqueue *fiq = &fc->iq;
void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
req->end = NULL;
list_del_init(&req->list);
+ spin_lock(&fiq->waitq.lock);
list_del_init(&req->intr_entry);
+ spin_unlock(&fiq->waitq.lock);
WARN_ON(test_bit(FR_PENDING, &req->flags));
WARN_ON(test_bit(FR_SENT, &req->flags));
smp_wmb();
@@ -398,13 +405,16 @@ __releases(fc->lock)
static void queue_interrupt(struct fuse_iqueue *fiq, struct fuse_req *req)
{
+ spin_lock(&fiq->waitq.lock);
list_add_tail(&req->intr_entry, &fiq->interrupts);
- wake_up(&fiq->waitq);
+ wake_up_locked(&fiq->waitq);
+ spin_unlock(&fiq->waitq.lock);
kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
}
static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
{
+ struct fuse_iqueue *fiq = &fc->iq;
int err;
if (!fc->no_interrupt) {
@@ -417,7 +427,7 @@ static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
spin_lock(&fc->lock);
set_bit(FR_INTERRUPTED, &req->flags);
if (test_bit(FR_SENT, &req->flags))
- queue_interrupt(&fc->iq, req);
+ queue_interrupt(fiq, req);
spin_unlock(&fc->lock);
}
@@ -430,14 +440,17 @@ static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
return;
spin_lock(&fc->lock);
+ spin_lock(&fiq->waitq.lock);
/* Request is not yet in userspace, bail out */
if (test_bit(FR_PENDING, &req->flags)) {
list_del(&req->list);
+ spin_unlock(&fiq->waitq.lock);
spin_unlock(&fc->lock);
__fuse_put_request(req);
req->out.h.error = -EINTR;
return;
}
+ spin_unlock(&fiq->waitq.lock);
spin_unlock(&fc->lock);
}
@@ -455,11 +468,14 @@ static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req,
BUG_ON(test_bit(FR_BACKGROUND, &req->flags));
spin_lock(&fc->lock);
+ spin_lock(&fiq->waitq.lock);
if (!fiq->connected) {
spin_unlock(&fc->lock);
+ spin_unlock(&fiq->waitq.lock);
req->out.h.error = -ENOTCONN;
} else if (ff && test_bit(FUSE_S_FAIL_IMMEDIATELY, &ff->ff_state)) {
spin_unlock(&fc->lock);
+ spin_unlock(&fiq->waitq.lock);
req->out.h.error = -EIO;
} else {
req->in.h.unique = fuse_get_unique(fiq);
@@ -467,6 +483,7 @@ static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req,
/* acquire extra reference, since request is still needed
after request_end() */
__fuse_get_request(req);
+ spin_unlock(&fiq->waitq.lock);
spin_unlock(&fc->lock);
request_wait_answer(fc, req);
@@ -549,10 +566,12 @@ static int fuse_request_send_notify_reply(struct fuse_conn *fc,
__clear_bit(FR_ISREPLY, &req->flags);
req->in.h.unique = unique;
spin_lock(&fc->lock);
+ spin_lock(&fiq->waitq.lock);
if (fiq->connected) {
queue_request(fiq, req);
err = 0;
}
+ spin_unlock(&fiq->waitq.lock);
spin_unlock(&fc->lock);
return err;
@@ -1028,8 +1047,10 @@ static int request_pending(struct fuse_iqueue *fiq)
/* Wait until a request is available on the pending list */
static void request_wait(struct fuse_conn *fc)
+__releases(fc->iq.waitq.lock)
__releases(fc->lock)
__acquires(fc->lock)
+__acquires(fc->iq.waitq.lock)
{
struct fuse_iqueue *fiq = &fc->iq;
DECLARE_WAITQUEUE(wait, current);
@@ -1040,9 +1061,11 @@ __acquires(fc->lock)
if (signal_pending(current))
break;
+ spin_unlock(&fiq->waitq.lock);
spin_unlock(&fc->lock);
schedule();
spin_lock(&fc->lock);
+ spin_lock(&fiq->waitq.lock);
}
set_current_state(TASK_RUNNING);
remove_wait_queue(&fiq->waitq, &wait);
@@ -1058,15 +1081,17 @@ __acquires(fc->lock)
*/
static int fuse_read_interrupt(struct fuse_conn *fc, struct fuse_copy_state *cs,
size_t nbytes, struct fuse_req *req)
+__releases(fc->iq.waitq.lock)
__releases(fc->lock)
{
+ struct fuse_iqueue *fiq = &fc->iq;
struct fuse_in_header ih;
struct fuse_interrupt_in arg;
unsigned reqsize = sizeof(ih) + sizeof(arg);
int err;
list_del_init(&req->intr_entry);
- req->intr_unique = fuse_get_unique(&fc->iq);
+ req->intr_unique = fuse_get_unique(fiq);
memset(&ih, 0, sizeof(ih));
memset(&arg, 0, sizeof(arg));
ih.len = reqsize;
@@ -1074,6 +1099,7 @@ __releases(fc->lock)
ih.unique = req->intr_unique;
arg.unique = req->in.h.unique;
+ spin_unlock(&fiq->waitq.lock);
spin_unlock(&fc->lock);
if (nbytes < reqsize)
return -EINVAL;
@@ -1111,6 +1137,7 @@ static struct fuse_forget_link *dequeue_forget(struct fuse_iqueue *fiq,
static int fuse_read_single_forget(struct fuse_conn *fc,
struct fuse_copy_state *cs,
size_t nbytes)
+__releases(fc->iq.waitq.lock)
__releases(fc->lock)
{
int err;
@@ -1126,6 +1153,7 @@ __releases(fc->lock)
.len = sizeof(ih) + sizeof(arg),
};
+ spin_unlock(&fiq->waitq.lock);
spin_unlock(&fc->lock);
kfree(forget);
if (nbytes < ih.len)
@@ -1144,6 +1172,7 @@ __releases(fc->lock)
static int fuse_read_batch_forget(struct fuse_conn *fc,
struct fuse_copy_state *cs, size_t nbytes)
+__releases(fc->iq.waitq.lock)
__releases(fc->lock)
{
int err;
@@ -1159,12 +1188,14 @@ __releases(fc->lock)
};
if (nbytes < ih.len) {
+ spin_unlock(&fiq->waitq.lock);
spin_unlock(&fc->lock);
return -EINVAL;
}
max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one);
head = dequeue_forget(fiq, max_forgets, &count);
+ spin_unlock(&fiq->waitq.lock);
spin_unlock(&fc->lock);
arg.count = count;
@@ -1194,6 +1225,7 @@ __releases(fc->lock)
static int fuse_read_forget(struct fuse_conn *fc, struct fuse_copy_state *cs,
size_t nbytes)
+__releases(fc->iq.waitq.lock)
__releases(fc->lock)
{
struct fuse_iqueue *fiq = &fc->iq;
@@ -1224,6 +1256,7 @@ static ssize_t fuse_dev_do_read(struct fuse_conn *fc, struct file *file,
restart:
spin_lock(&fc->lock);
+ spin_lock(&fiq->waitq.lock);
err = -EAGAIN;
if ((file->f_flags & O_NONBLOCK) && fiq->connected &&
!request_pending(fiq))
@@ -1254,6 +1287,8 @@ static ssize_t fuse_dev_do_read(struct fuse_conn *fc, struct file *file,
req = list_entry(fiq->pending.next, struct fuse_req, list);
clear_bit(FR_PENDING, &req->flags);
list_del_init(&req->list);
+ spin_unlock(&fiq->waitq.lock);
+
list_add(&req->list, &fc->io);
in = &req->in;
@@ -1297,6 +1332,7 @@ static ssize_t fuse_dev_do_read(struct fuse_conn *fc, struct file *file,
return reqsize;
err_unlock:
+ spin_unlock(&fiq->waitq.lock);
spin_unlock(&fc->lock);
return err;
}
@@ -2050,10 +2086,12 @@ static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
poll_wait(file, &fiq->waitq, wait);
spin_lock(&fc->lock);
+ spin_lock(&fiq->waitq.lock);
if (!fiq->connected)
mask = POLLERR;
else if (request_pending(fiq))
mask |= POLLIN | POLLRDNORM;
+ spin_unlock(&fiq->waitq.lock);
spin_unlock(&fc->lock);
return mask;
@@ -2136,11 +2174,13 @@ void fuse_abort_conn(struct fuse_conn *fc)
fc->max_background = UINT_MAX;
flush_bg_queue(fc);
+ spin_lock(&fiq->waitq.lock);
fiq->connected = 0;
list_splice_init(&fiq->pending, &to_end2);
while (forget_pending(fiq))
kfree(dequeue_forget(fiq, 1, NULL));
- wake_up_all(&fiq->waitq);
+ wake_up_all_locked(&fiq->waitq);
+ spin_unlock(&fiq->waitq.lock);
kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
list_splice_init(&fc->processing, &to_end2);
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