amiga floppy: Stop sharing request queue across multiple gendisks

o Use one request queue per gendisk instead of sharing request queue

o Don't have hardware. No compile testing or run time testing done. Completely
  untested.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

diff --git a/drivers/block/amiflop.c b/drivers/block/amiflop.c
index 76f114f0bba32f5d0396ac9b2a1ec2a88963f7c1..ead8b7792c528f98c2714badeac20b2d8d85964b 100644 (file)
--- a/drivers/block/amiflop.c
+++ b/drivers/block/amiflop.c
@@ -114,8 +114,6 @@ static unsigned long int fd_def_df0 = FD_DD_3;     /* default for df0 if it does
 module_param(fd_def_df0, ulong, 0);
 MODULE_LICENSE("GPL");
 
-static struct request_queue *floppy_queue;
-
 /*
  *  Macros
  */
@@ -164,6 +162,7 @@ static volatile int selected = -1;  /* currently selected drive */
 static int writepending;
 static int writefromint;
 static char *raw_buf;
+static int fdc_queue;
 
 static DEFINE_SPINLOCK(amiflop_lock);
 
@@ -1334,6 +1333,42 @@ static int get_track(int drive, int track)
        return -1;
 }
 
+/*
+ * Round-robin between our available drives, doing one request from each
+ */
+static struct request *set_next_request(void)
+{
+       struct request_queue *q;
+       int cnt = FD_MAX_UNITS;
+       struct request *rq;
+
+       /* Find next queue we can dispatch from */
+       fdc_queue = fdc_queue + 1;
+       if (fdc_queue == FD_MAX_UNITS)
+               fdc_queue = 0;
+
+       for(cnt = FD_MAX_UNITS; cnt > 0, cnt--) {
+
+               if (unit[fdc_queue].type->code == FD_NODRIVE) {
+                       if (++fdc_queue == FD_MAX_UNITS)
+                               fdc_queue = 0;
+                       cotinue;
+               }
+
+               q = unit[fdc_queue].gendisk->queue;
+               if (q) {
+                       rq = blk_fetch_request(q);
+                       if (rq)
+                               break;
+               }
+
+               if (++fdc_queue == FD_MAX_UNITS)
+                       fdc_queue = 0;
+       }
+
+       return rq;
+}
+
 static void redo_fd_request(void)
 {
        struct request *rq;
@@ -1345,7 +1380,7 @@ static void redo_fd_request(void)
        int err;
 
 next_req:
-       rq = blk_fetch_request(floppy_queue);
+       rq = set_next_request();
        if (!rq) {
                /* Nothing left to do */
                return;
@@ -1682,6 +1717,13 @@ static int __init fd_probe_drives(void)
                        continue;
                }
                unit[drive].gendisk = disk;
+
+               disk->queue = blk_init_queue(do_fd_request, &amiflop_lock);
+               if (!disk->queue) {
+                       unit[drive].type->code = FD_NODRIVE;
+                       continue;
+               }
+
                drives++;
                if ((unit[drive].trackbuf = kmalloc(FLOPPY_MAX_SECTORS * 512, GFP_KERNEL)) == NULL) {
                        printk("no mem for ");
@@ -1695,7 +1737,6 @@ static int __init fd_probe_drives(void)
                disk->fops = &floppy_fops;
                sprintf(disk->disk_name, "fd%d", drive);
                disk->private_data = &unit[drive];
-               disk->queue = floppy_queue;
                set_capacity(disk, 880*2);
                add_disk(disk);
        }
@@ -1743,11 +1784,6 @@ static int __init amiga_floppy_probe(struct platform_device *pdev)
                goto out_irq2;
        }
 
-       ret = -ENOMEM;
-       floppy_queue = blk_init_queue(do_fd_request, &amiflop_lock);
-       if (!floppy_queue)
-               goto out_queue;
-
        ret = -ENODEV;
        if (fd_probe_drives() < 1) /* No usable drives */
                goto out_probe;
@@ -1791,7 +1827,6 @@ static int __init amiga_floppy_probe(struct platform_device *pdev)
        return 0;
 
 out_probe:
-       blk_cleanup_queue(floppy_queue);
 out_queue:
        free_irq(IRQ_AMIGA_CIAA_TB, NULL);
 out_irq2:
@@ -1810,9 +1845,12 @@ static int __exit amiga_floppy_remove(struct platform_device *pdev)
 
        for( i = 0; i < FD_MAX_UNITS; i++) {
                if (unit[i].type->code != FD_NODRIVE) {
+                       struct request_queue *q = unit[i].gendisk->queue;
                        del_gendisk(unit[i].gendisk);
                        put_disk(unit[i].gendisk);
                        kfree(unit[i].trackbuf);
+                       if (q)
+                               blk_cleanup_queue(q);
                }
        }
        blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256);
@@ -1820,7 +1858,6 @@ static int __exit amiga_floppy_remove(struct platform_device *pdev)
        free_irq(IRQ_AMIGA_DSKBLK, NULL);
        custom.dmacon = DMAF_DISK; /* disable DMA */
        amiga_chip_free(raw_buf);
-       blk_cleanup_queue(floppy_queue);
        unregister_blkdev(FLOPPY_MAJOR, "fd");
 }
 #endif