This enables bsg to resize the queue depth via
SG_SET_COMMAND_Q. bsg_command structures are allocated via mempool
because the previous way to use contiguous memory makes it difficult
to resize the queue depth when a bsg_device has outstanding commands.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
---
block/bsg.c | 112 +++++++++++++++++++++++-----------------------------------
1 files changed, 45 insertions(+), 67 deletions(-)
diff --git a/block/bsg.c b/block/bsg.c
index 9d77a0c..af46f54 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -33,8 +33,6 @@ #include <scsi/sg.h>
static char bsg_version[] = "block layer sg (bsg) 0.4";
-struct bsg_command;
-
struct bsg_device {
struct gendisk *disk;
request_queue_t *queue;
@@ -46,8 +44,7 @@ struct bsg_device {
int minor;
int queued_cmds;
int done_cmds;
- unsigned long *cmd_bitmap;
- struct bsg_command *cmd_map;
+ mempool_t *bsg_cmd_q;
wait_queue_head_t wq_done;
wait_queue_head_t wq_free;
char name[BDEVNAME_SIZE];
@@ -55,19 +52,26 @@ struct bsg_device {
unsigned long flags;
};
+/*
+ * our internal command type
+ */
+struct bsg_command {
+ struct bsg_device *bd;
+ struct list_head list;
+ struct request *rq;
+ struct bio *bio;
+ int err;
+ struct sg_io_v4 hdr;
+ struct sg_io_v4 __user *uhdr;
+ char sense[SCSI_SENSE_BUFFERSIZE];
+};
+
enum {
BSG_F_BLOCK = 1,
BSG_F_WRITE_PERM = 2,
};
-/*
- * command allocation bitmap defines
- */
-#define BSG_CMDS_PAGE_ORDER (1)
-#define BSG_CMDS_PER_LONG (sizeof(unsigned long) * 8)
-#define BSG_CMDS_MASK (BSG_CMDS_PER_LONG - 1)
-#define BSG_CMDS_BYTES (PAGE_SIZE * (1 << BSG_CMDS_PAGE_ORDER))
-#define BSG_CMDS (BSG_CMDS_BYTES / sizeof(struct bsg_command))
+#define BSG_DEFAULT_CMDS (64)
#undef BSG_DEBUG
@@ -94,31 +98,18 @@ static struct hlist_head bsg_device_list
static struct class *bsg_class;
static LIST_HEAD(bsg_class_list);
-/*
- * our internal command type
- */
-struct bsg_command {
- struct bsg_device *bd;
- struct list_head list;
- struct request *rq;
- struct bio *bio;
- int err;
- struct sg_io_v4 hdr;
- struct sg_io_v4 __user *uhdr;
- char sense[SCSI_SENSE_BUFFERSIZE];
-};
+static struct kmem_cache *bsg_cmd_cachep;
static void bsg_free_command(struct bsg_command *bc)
{
struct bsg_device *bd = bc->bd;
- unsigned long bitnr = bc - bd->cmd_map;
unsigned long flags;
- dprintk("%s: command bit offset %lu\n", bd->name, bitnr);
+ dprintk("%s: command free %p\n", bd->name, bc);
+ mempool_free(bc, bd->bsg_cmd_q);
spin_lock_irqsave(&bd->lock, flags);
bd->queued_cmds--;
- __clear_bit(bitnr, bd->cmd_bitmap);
spin_unlock_irqrestore(&bd->lock, flags);
wake_up(&bd->wq_free);
@@ -127,29 +118,18 @@ static void bsg_free_command(struct bsg_
static struct bsg_command *__bsg_alloc_command(struct bsg_device *bd)
{
struct bsg_command *bc = NULL;
- unsigned long *map;
- int free_nr;
spin_lock_irq(&bd->lock);
-
if (bd->queued_cmds >= bd->max_queue)
goto out;
-
- for (free_nr = 0, map = bd->cmd_bitmap; *map == ~0UL; map++)
- free_nr += BSG_CMDS_PER_LONG;
-
- BUG_ON(*map == ~0UL);
-
bd->queued_cmds++;
- free_nr += ffz(*map);
- __set_bit(free_nr, bd->cmd_bitmap);
spin_unlock_irq(&bd->lock);
- bc = bd->cmd_map + free_nr;
+ bc = mempool_alloc(bd->bsg_cmd_q, GFP_NOWAIT);
memset(bc, 0, sizeof(*bc));
bc->bd = bd;
INIT_LIST_HEAD(&bc->list);
- dprintk("%s: returning free cmd %p (bit %d)\n", bd->name, bc, free_nr);
+ dprintk("%s: returning free cmd %p\n", bd->name, bc);
return bc;
out:
dprintk("%s: failed (depth %d)\n", bd->name, bd->queued_cmds);
@@ -356,8 +336,8 @@ static void bsg_rq_end_io(struct request
struct bsg_device *bd = bc->bd;
unsigned long flags;
- dprintk("%s: finished rq %p bc %p, bio %p offset %Zd stat %d\n",
- bd->name, rq, bc, bc->bio, bc - bd->cmd_map, uptodate);
+ dprintk("%s: finished rq %p bc %p, bio %p stat %d\n",
+ bd->name, rq, bc, bc->bio, uptodate);
bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
@@ -705,19 +685,13 @@ bsg_write(struct file *file, const char
static void bsg_free_device(struct bsg_device *bd)
{
- if (bd->cmd_map)
- free_pages((unsigned long) bd->cmd_map, BSG_CMDS_PAGE_ORDER);
-
- kfree(bd->cmd_bitmap);
+ mempool_destroy(bd->bsg_cmd_q);
kfree(bd);
}
static struct bsg_device *bsg_alloc_device(void)
{
- struct bsg_command *cmd_map;
- unsigned long *cmd_bitmap;
struct bsg_device *bd;
- int bits;
bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL);
if (unlikely(!bd))
@@ -725,19 +699,10 @@ static struct bsg_device *bsg_alloc_devi
spin_lock_init(&bd->lock);
- bd->max_queue = BSG_CMDS;
-
- bits = (BSG_CMDS / BSG_CMDS_PER_LONG) + 1;
- cmd_bitmap = kzalloc(bits * sizeof(unsigned long), GFP_KERNEL);
- if (!cmd_bitmap)
+ bd->max_queue = BSG_DEFAULT_CMDS;
+ bd->bsg_cmd_q = mempool_create_slab_pool(bd->max_queue, bsg_cmd_cachep);
+ if (unlikely(!bd->bsg_cmd_q))
goto out_free_bd;
- bd->cmd_bitmap = cmd_bitmap;
-
- cmd_map = (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
- BSG_CMDS_PAGE_ORDER);
- if (!cmd_map)
- goto out_free_bitmap;
- bd->cmd_map = cmd_map;
INIT_LIST_HEAD(&bd->busy_list);
INIT_LIST_HEAD(&bd->done_list);
@@ -747,8 +712,6 @@ static struct bsg_device *bsg_alloc_devi
init_waitqueue_head(&bd->wq_done);
return bd;
-out_free_bitmap:
- kfree(cmd_bitmap);
out_free_bd:
kfree(bd);
return NULL;
@@ -918,15 +881,22 @@ bsg_ioctl(struct inode *inode, struct fi
*/
case SG_GET_COMMAND_Q:
return put_user(bd->max_queue, uarg);
- case SG_SET_COMMAND_Q: {
- int queue;
+ case SG_SET_COMMAND_Q: {
+ int queue, ret;
if (get_user(queue, uarg))
return -EFAULT;
- if (queue > BSG_CMDS || queue < 1)
+
+ if (queue < 1)
return -EINVAL;
+ ret = mempool_resize(bd->bsg_cmd_q, queue, GFP_KERNEL);
+ if (ret)
+ return ret;
+
+ spin_lock_irq(&bd->lock);
bd->max_queue = queue;
+ spin_unlock_irq(&bd->lock);
return 0;
}
@@ -1048,6 +1018,14 @@ static int __init bsg_init(void)
return ret;
}
+ bsg_cmd_cachep = kmem_cache_create("bsg_cmd", sizeof(struct bsg_command),
+ 0, 0, NULL, NULL);
+ if (!bsg_cmd_cachep) {
+ class_destroy(bsg_class);
+ unregister_chrdev(BSG_MAJOR, "bsg");
+ return -ENOMEM;
+ }
+
printk(KERN_INFO "%s loaded\n", bsg_version);
return 0;
}
--
1.4.3.2
-
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