jsflash: stop sharing request queue across multiple gendisks

Compile-tested only (by hacking it to compile on x86).

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 36 insertions, 14 deletions

diff --git a/drivers/sbus/char/jsflash.c b/drivers/sbus/char/jsflash.c
index 6ff61dad5e21..62fed9dc893e 100644
--- a/drivers/sbus/char/jsflash.c
+++ b/drivers/sbus/char/jsflash.c
@@ -183,11 +183,33 @@ static void jsfd_read(char *buf, unsigned long p, size_t togo) {
         }
 }
 
-static void jsfd_do_request(struct request_queue *q)
+static int jsfd_queue;
+
+static struct request *jsfd_next_request(void)
+{
+        struct request_queue *q;
+        struct request *rq;
+        int old_pos = jsfd_queue;
+
+        do {
+                q = jsfd_disk[jsfd_queue]->queue;
+                if (++jsfd_queue == JSF_MAX)
+                        jsfd_queue = 0;
+                if (q) {
+                        rq = blk_fetch_request(q);
+                        if (rq)
+                                return rq;
+                }
+        } while (jsfd_queue != old_pos);
+
+        return NULL;
+}
+
+static void jsfd_request(void)
 {
         struct request *req;
 
-        req = blk_fetch_request(q);
+        req = jsfd_next_request();
         while (req) {
                 struct jsfd_part *jdp = req->rq_disk->private_data;
                 unsigned long offset = blk_rq_pos(req) << 9;
@@ -211,10 +233,15 @@ static void jsfd_do_request(struct request_queue *q)
                 err = 0;
         end:
                 if (!__blk_end_request_cur(req, err))
-                        req = blk_fetch_request(q);
+                        req = jsfd_next_request();
         }
 }
 
+static void jsfd_do_request(struct request_queue *q)
+{
+        jsfd_request();
+}
+
 /*
  * The memory devices use the full 32/64 bits of the offset, and so we cannot
  * check against negative addresses: they are ok. The return value is weird,
@@ -544,8 +571,6 @@ static int jsflash_init(void)
         return 0;
 }
 
-static struct request_queue *jsf_queue;
-
 static int jsfd_init(void)
 {
         static DEFINE_SPINLOCK(lock);
@@ -562,6 +587,11 @@ static int jsfd_init(void)
                 struct gendisk *disk = alloc_disk(1);
                 if (!disk)
                         goto out;
+                disk->queue = blk_init_queue(jsfd_do_request, &lock);
+                if (!disk->queue) {
+                        put_disk(disk);
+                        goto out;
+                }
                 jsfd_disk[i] = disk;
         }
 
@@ -570,13 +600,6 @@ static int jsfd_init(void)
                 goto out;
         }
 
-        jsf_queue = blk_init_queue(jsfd_do_request, &lock);
-        if (!jsf_queue) {
-                err = -ENOMEM;
-                unregister_blkdev(JSFD_MAJOR, "jsfd");
-                goto out;
-        }
-
         for (i = 0; i < JSF_MAX; i++) {
                 struct gendisk *disk = jsfd_disk[i];
                 if ((i & JSF_PART_MASK) >= JSF_NPART) continue;
@@ -589,7 +612,6 @@ static int jsfd_init(void)
                 disk->fops = &jsfd_fops;
                 set_capacity(disk, jdp->dsize >> 9);
                 disk->private_data = jdp;
-                disk->queue = jsf_queue;
                 add_disk(disk);
                 set_disk_ro(disk, 1);
         }
@@ -619,6 +641,7 @@ static void __exit jsflash_cleanup_module(void)
         for (i = 0; i < JSF_MAX; i++) {
                 if ((i & JSF_PART_MASK) >= JSF_NPART) continue;
                 del_gendisk(jsfd_disk[i]);
+                blk_cleanup_queue(jsfd_disk[i]->queue);
                 put_disk(jsfd_disk[i]);
         }
         if (jsf0.busy)
@@ -628,7 +651,6 @@ static void __exit jsflash_cleanup_module(void)
 
         misc_deregister(&jsf_dev);
         unregister_blkdev(JSFD_MAJOR, "jsfd");
-        blk_cleanup_queue(jsf_queue);
 }
 
 module_init(jsflash_init_module);