parport/pf: stop sharing request queue across multiple gendisks

Compile-tested only.

Cc: Tim Waugh <tim@cyberelk.net>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/drivers/block/paride/pf.c b/drivers/block/paride/pf.c
index 14c5d32f5d8bc067532ba6ea95070d5c2a76db73..f24ca7315ddc91e24e2cfa6ca62c7f3a5578a296 100644 (file)
--- a/drivers/block/paride/pf.c
+++ b/drivers/block/paride/pf.c
@@ -287,6 +287,12 @@ static void __init pf_init_units(void)
                struct gendisk *disk = alloc_disk(1);
                if (!disk)
                        continue;
+               disk->queue = blk_init_queue(do_pf_request, &pf_spin_lock);
+               if (!disk->queue) {
+                       put_disk(disk);
+                       return;
+               }
+               blk_queue_max_segments(disk->queue, cluster);
                pf->disk = disk;
                pf->pi = &pf->pia;
                pf->media_status = PF_NM;
@@ -772,7 +778,28 @@ static int pf_ready(void)
        return (((status_reg(pf_current) & (STAT_BUSY | pf_mask)) == pf_mask));
 }
 
-static struct request_queue *pf_queue;
+static int pf_queue;
+
+static int set_next_request(void)
+{
+       struct pf_unit *pf;
+       struct request_queue *q;
+       int old_pos = pf_queue;
+
+       do {
+               pf = &units[pf_queue];
+               q = pf->present ? pf->disk->queue : NULL;
+               if (++pf_queue == PF_UNITS)
+                       pf_queue = 0;
+               if (q) {
+                       pf_req = blk_fetch_request(q);
+                       if (pf_req)
+                               break;
+               }
+       } while (pf_queue != old_pos);
+
+       return pf_req != NULL;
+}
 
 static void pf_end_request(int err)
 {
@@ -780,16 +807,13 @@ static void pf_end_request(int err)
                pf_req = NULL;
 }
 
-static void do_pf_request(struct request_queue * q)
+static void pf_request(void)
 {
        if (pf_busy)
                return;
 repeat:
-       if (!pf_req) {
-               pf_req = blk_fetch_request(q);
-               if (!pf_req)
-                       return;
-       }
+       if (!pf_req && !set_next_request())
+               return;
 
        pf_current = pf_req->rq_disk->private_data;
        pf_block = blk_rq_pos(pf_req);
@@ -817,6 +841,11 @@ repeat:
        }
 }
 
+static void do_pf_request(struct request_queue *q)
+{
+       pf_request();
+}
+
 static int pf_next_buf(void)
 {
        unsigned long saved_flags;
@@ -846,7 +875,7 @@ static inline void next_request(int err)
        spin_lock_irqsave(&pf_spin_lock, saved_flags);
        pf_end_request(err);
        pf_busy = 0;
-       do_pf_request(pf_queue);
+       pf_request();
        spin_unlock_irqrestore(&pf_spin_lock, saved_flags);
 }
 
@@ -972,15 +1001,6 @@ static int __init pf_init(void)
                        put_disk(pf->disk);
                return -EBUSY;
        }
-       pf_queue = blk_init_queue(do_pf_request, &pf_spin_lock);
-       if (!pf_queue) {
-               unregister_blkdev(major, name);
-               for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++)
-                       put_disk(pf->disk);
-               return -ENOMEM;
-       }
-
-       blk_queue_max_segments(pf_queue, cluster);
 
        for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++) {
                struct gendisk *disk = pf->disk;
@@ -988,7 +1008,6 @@ static int __init pf_init(void)
                if (!pf->present)
                        continue;
                disk->private_data = pf;
-               disk->queue = pf_queue;
                add_disk(disk);
        }
        return 0;
@@ -1003,10 +1022,10 @@ static void __exit pf_exit(void)
                if (!pf->present)
                        continue;
                del_gendisk(pf->disk);
+               blk_cleanup_queue(pf->disk->queue);
                put_disk(pf->disk);
                pi_release(pf->pi);
        }
-       blk_cleanup_queue(pf_queue);
 }
 
 MODULE_LICENSE("GPL");