Backport from ml:
commit fd22d62ed0c36e260ac3e13167bc073f28407c70
Author: Miklos Szeredi <[email protected]>
Date: Wed Jul 1 16:26:03 2015 +0200
fuse: no fc->lock for iqueue parts
Remove fc->lock protection from input queue members, now protected by
fiq->waitq.lock.
Signed-off-by: Miklos Szeredi <[email protected]>
Reviewed-by: Ashish Samant <[email protected]>
Signed-off-by: Maxim Patlasov <[email protected]>
---
fs/fuse/dev.c | 72 ++++++++++++++++-----------------------------------------
1 file changed, 20 insertions(+), 52 deletions(-)
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 5a65afa..de6731b 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -323,7 +323,6 @@ void fuse_queue_forget(struct fuse_conn *fc, struct
fuse_forget_link *forget,
forget->forget_one.nodeid = nodeid;
forget->forget_one.nlookup = nlookup;
- spin_lock(&fc->lock);
spin_lock(&fiq->waitq.lock);
if (fiq->connected) {
fiq->forget_list_tail->next = forget;
@@ -334,7 +333,6 @@ void fuse_queue_forget(struct fuse_conn *fc, struct
fuse_forget_link *forget,
kfree(forget);
}
spin_unlock(&fiq->waitq.lock);
- spin_unlock(&fc->lock);
}
static void flush_bg_queue(struct fuse_conn *fc)
@@ -426,13 +424,11 @@ static void request_wait_answer(struct fuse_conn *fc,
struct fuse_req *req)
if (!err)
return;
- spin_lock(&fc->lock);
set_bit(FR_INTERRUPTED, &req->flags);
/* matches barrier in fuse_dev_do_read() */
smp_mb__after_atomic();
if (test_bit(FR_SENT, &req->flags))
queue_interrupt(fiq, req);
- spin_unlock(&fc->lock);
}
if (!test_bit(FR_FORCE, &req->flags)) {
@@ -443,19 +439,16 @@ static void request_wait_answer(struct fuse_conn *fc,
struct fuse_req *req)
if (!err)
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);
}
/*
@@ -471,14 +464,11 @@ static void __fuse_request_send(struct fuse_conn *fc,
struct fuse_req *req,
struct fuse_iqueue *fiq = &fc->iq;
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 {
@@ -488,7 +478,6 @@ static void __fuse_request_send(struct fuse_conn *fc,
struct fuse_req *req,
after request_end() */
__fuse_get_request(req);
spin_unlock(&fiq->waitq.lock);
- spin_unlock(&fc->lock);
request_wait_answer(fc, req);
/* Pairs with smp_wmb() in request_end() */
@@ -569,14 +558,12 @@ 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;
}
@@ -1050,13 +1037,10 @@ 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)
+static void request_wait(struct fuse_iqueue *fiq)
+__releases(fiq->waitq.lock)
+__acquires(fiq->waitq.lock)
{
- struct fuse_iqueue *fiq = &fc->iq;
DECLARE_WAITQUEUE(wait, current);
add_wait_queue_exclusive(&fiq->waitq, &wait);
@@ -1066,9 +1050,7 @@ __acquires(fc->iq.waitq.lock)
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);
@@ -1081,14 +1063,13 @@ __acquires(fc->iq.waitq.lock)
* Unlike other requests this is assembled on demand, without a need
* to allocate a separate fuse_req structure.
*
- * Called with fc->lock held, releases it
+ * Called with fiq->waitq.lock held, releases it
*/
-static int fuse_read_interrupt(struct fuse_conn *fc, struct fuse_copy_state
*cs,
+static int fuse_read_interrupt(struct fuse_iqueue *fiq,
+ struct fuse_copy_state *cs,
size_t nbytes, struct fuse_req *req)
-__releases(fc->iq.waitq.lock)
-__releases(fc->lock)
+__releases(fiq->waitq.lock)
{
- struct fuse_iqueue *fiq = &fc->iq;
struct fuse_in_header ih;
struct fuse_interrupt_in arg;
unsigned reqsize = sizeof(ih) + sizeof(arg);
@@ -1104,7 +1085,6 @@ __releases(fc->lock)
arg.unique = req->in.h.unique;
spin_unlock(&fiq->waitq.lock);
- spin_unlock(&fc->lock);
if (nbytes < reqsize)
return -EINVAL;
@@ -1138,14 +1118,12 @@ static struct fuse_forget_link *dequeue_forget(struct
fuse_iqueue *fiq,
return head;
}
-static int fuse_read_single_forget(struct fuse_conn *fc,
+static int fuse_read_single_forget(struct fuse_iqueue *fiq,
struct fuse_copy_state *cs,
size_t nbytes)
-__releases(fc->iq.waitq.lock)
-__releases(fc->lock)
+__releases(fiq->waitq.lock)
{
int err;
- struct fuse_iqueue *fiq = &fc->iq;
struct fuse_forget_link *forget = dequeue_forget(fiq, 1, NULL);
struct fuse_forget_in arg = {
.nlookup = forget->forget_one.nlookup,
@@ -1158,7 +1136,6 @@ __releases(fc->lock)
};
spin_unlock(&fiq->waitq.lock);
- spin_unlock(&fc->lock);
kfree(forget);
if (nbytes < ih.len)
return -EINVAL;
@@ -1174,16 +1151,14 @@ __releases(fc->lock)
return ih.len;
}
-static int fuse_read_batch_forget(struct fuse_conn *fc,
+static int fuse_read_batch_forget(struct fuse_iqueue *fiq,
struct fuse_copy_state *cs, size_t nbytes)
-__releases(fc->iq.waitq.lock)
-__releases(fc->lock)
+__releases(fiq->waitq.lock)
{
int err;
unsigned max_forgets;
unsigned count;
struct fuse_forget_link *head;
- struct fuse_iqueue *fiq = &fc->iq;
struct fuse_batch_forget_in arg = { .count = 0 };
struct fuse_in_header ih = {
.opcode = FUSE_BATCH_FORGET,
@@ -1193,14 +1168,12 @@ __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;
ih.len += count * sizeof(struct fuse_forget_one);
@@ -1227,17 +1200,15 @@ __releases(fc->lock)
return ih.len;
}
-static int fuse_read_forget(struct fuse_conn *fc, struct fuse_copy_state *cs,
+static int fuse_read_forget(struct fuse_conn *fc, struct fuse_iqueue *fiq,
+ struct fuse_copy_state *cs,
size_t nbytes)
-__releases(fc->iq.waitq.lock)
-__releases(fc->lock)
+__releases(fiq->waitq.lock)
{
- struct fuse_iqueue *fiq = &fc->iq;
-
if (fc->minor < 16 || fiq->forget_list_head.next->next == NULL)
- return fuse_read_single_forget(fc, cs, nbytes);
+ return fuse_read_single_forget(fiq, cs, nbytes);
else
- return fuse_read_batch_forget(fc, cs, nbytes);
+ return fuse_read_batch_forget(fiq, cs, nbytes);
}
/*
@@ -1259,14 +1230,13 @@ static ssize_t fuse_dev_do_read(struct fuse_conn *fc,
struct file *file,
unsigned reqsize;
restart:
- spin_lock(&fc->lock);
spin_lock(&fiq->waitq.lock);
err = -EAGAIN;
if ((file->f_flags & O_NONBLOCK) && fiq->connected &&
!request_pending(fiq))
goto err_unlock;
- request_wait(fc);
+ request_wait(fiq);
err = -ENODEV;
if (!fiq->connected)
goto err_unlock;
@@ -1277,12 +1247,12 @@ static ssize_t fuse_dev_do_read(struct fuse_conn *fc,
struct file *file,
if (!list_empty(&fiq->interrupts)) {
req = list_entry(fiq->interrupts.next, struct fuse_req,
intr_entry);
- return fuse_read_interrupt(fc, cs, nbytes, req);
+ return fuse_read_interrupt(fiq, cs, nbytes, req);
}
if (forget_pending(fiq)) {
if (list_empty(&fiq->pending) || fiq->forget_batch-- > 0)
- return fuse_read_forget(fc, cs, nbytes);
+ return fuse_read_forget(fc, fiq, cs, nbytes);
if (fiq->forget_batch <= -8)
fiq->forget_batch = 16;
@@ -1293,6 +1263,7 @@ static ssize_t fuse_dev_do_read(struct fuse_conn *fc,
struct file *file,
list_del_init(&req->list);
spin_unlock(&fiq->waitq.lock);
+ spin_lock(&fc->lock);
list_add(&req->list, &fc->io);
in = &req->in;
@@ -1339,7 +1310,6 @@ static ssize_t fuse_dev_do_read(struct fuse_conn *fc,
struct file *file,
err_unlock:
spin_unlock(&fiq->waitq.lock);
- spin_unlock(&fc->lock);
return err;
}
@@ -2091,14 +2061,12 @@ static unsigned fuse_dev_poll(struct file *file,
poll_table *wait)
fiq = &fc->iq;
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;
}
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