fuse: pqueue locking

Add a fpq->lock for protecting members of struct fuse_pqueue and FR_LOCKED
request flag.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: Ashish Samant <ashish.samant@oracle.com>

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 3e84300..32e0e74 100644 (file)
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1291,7 +1291,9 @@ static ssize_t fuse_dev_do_read(struct fuse_conn *fc, struct file *file,
                request_end(fc, req);
                goto restart;
        }
+       spin_lock(&fpq->lock);
        list_add(&req->list, &fpq->io);
+       spin_unlock(&fpq->lock);
        spin_unlock(&fc->lock);
        cs->req = req;
        err = fuse_copy_one(cs, &in->h, sizeof(in->h));
@@ -1300,6 +1302,7 @@ static ssize_t fuse_dev_do_read(struct fuse_conn *fc, struct file *file,
                                     (struct fuse_arg *) in->args, 0);
        fuse_copy_finish(cs);
        spin_lock(&fc->lock);
+       spin_lock(&fpq->lock);
        clear_bit(FR_LOCKED, &req->flags);
        if (!fpq->connected) {
                err = -ENODEV;
@@ -1314,6 +1317,7 @@ static ssize_t fuse_dev_do_read(struct fuse_conn *fc, struct file *file,
                goto out_end;
        }
        list_move_tail(&req->list, &fpq->processing);
+       spin_unlock(&fpq->lock);
        set_bit(FR_SENT, &req->flags);
        /* matches barrier in request_wait_answer() */
        smp_mb__after_atomic();
@@ -1325,6 +1329,7 @@ static ssize_t fuse_dev_do_read(struct fuse_conn *fc, struct file *file,
 
 out_end:
        list_del_init(&req->list);
+       spin_unlock(&fpq->lock);
        request_end(fc, req);
        return err;
 
@@ -1893,16 +1898,19 @@ static ssize_t fuse_dev_do_write(struct fuse_conn *fc,
                goto err_finish;
 
        spin_lock(&fc->lock);
+       spin_lock(&fpq->lock);
        err = -ENOENT;
        if (!fpq->connected)
-               goto err_unlock;
+               goto err_unlock_pq;
 
        req = request_find(fpq, oh.unique);
        if (!req)
-               goto err_unlock;
+               goto err_unlock_pq;
 
        /* Is it an interrupt reply? */
        if (req->intr_unique == oh.unique) {
+               spin_unlock(&fpq->lock);
+
                err = -EINVAL;
                if (nbytes != sizeof(struct fuse_out_header))
                        goto err_unlock;
@@ -1921,6 +1929,7 @@ static ssize_t fuse_dev_do_write(struct fuse_conn *fc,
        list_move(&req->list, &fpq->io);
        req->out.h = oh;
        set_bit(FR_LOCKED, &req->flags);
+       spin_unlock(&fpq->lock);
        cs->req = req;
        if (!req->out.page_replace)
                cs->move_pages = 0;
@@ -1930,16 +1939,20 @@ static ssize_t fuse_dev_do_write(struct fuse_conn *fc,
        fuse_copy_finish(cs);
 
        spin_lock(&fc->lock);
+       spin_lock(&fpq->lock);
        clear_bit(FR_LOCKED, &req->flags);
        if (!fpq->connected)
                err = -ENOENT;
        else if (err)
                req->out.h.error = -EIO;
        list_del_init(&req->list);
+       spin_unlock(&fpq->lock);
        request_end(fc, req);
 
        return err ? err : nbytes;
 
+ err_unlock_pq:
+       spin_unlock(&fpq->lock);
  err_unlock:
        spin_unlock(&fc->lock);
  err_finish:
@@ -2130,6 +2143,7 @@ void fuse_abort_conn(struct fuse_conn *fc)
                fc->connected = 0;
                fc->blocked = 0;
                fuse_set_initialized(fc);
+               spin_lock(&fpq->lock);
                fpq->connected = 0;
                list_for_each_entry_safe(req, next, &fpq->io, list) {
                        req->out.h.error = -ECONNABORTED;
@@ -2140,6 +2154,7 @@ void fuse_abort_conn(struct fuse_conn *fc)
                        spin_unlock(&req->waitq.lock);
                }
                list_splice_init(&fpq->processing, &to_end2);
+               spin_unlock(&fpq->lock);
                fc->max_background = UINT_MAX;
                flush_bg_queue(fc);
 

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 5897d89..ad3799e 100644 (file)
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -405,6 +405,9 @@ struct fuse_pqueue {
        /** Connection established */
        unsigned connected;
 
+       /** Lock protecting accessess to  members of this structure */
+       spinlock_t lock;
+
        /** The list of requests being processed */
        struct list_head processing;
 

diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 88b9ca4..8373f59 100644 (file)
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -580,6 +580,7 @@ static void fuse_iqueue_init(struct fuse_iqueue *fiq)
 static void fuse_pqueue_init(struct fuse_pqueue *fpq)
 {
        memset(fpq, 0, sizeof(struct fuse_pqueue));
+       spin_lock_init(&fpq->lock);
        INIT_LIST_HEAD(&fpq->processing);
        INIT_LIST_HEAD(&fpq->io);
        fpq->connected = 1;