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xen/blkback: Move global/static variables into struct xen_blkbk. 

Bundle the lot of discrete variables into a single structure.
This is based on what was done in the xen-netback driver:
xen: netback: Move global/static variables into struct xen_netbk.
(094944631cc5a9d6e623302c987f78117c0bf7ac)

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Konrad Rzeszutek Wilk 2011-02-25 10:51:29 -05:00
parent efe08a3eec
commit e8e28871ed
1 changed files with 48 additions and 34 deletions
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82
drivers/xen/blkback/blkback.c
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@ -84,31 +84,34 @@ typedef struct {
struct list_head free_list;
} pending_req_t;
static pending_req_t *pending_reqs;
static struct list_head pending_free;
static DEFINE_SPINLOCK(pending_free_lock);
static DECLARE_WAIT_QUEUE_HEAD(pending_free_wq);
#define BLKBACK_INVALID_HANDLE (~0)
static struct page **pending_pages;
static grant_handle_t *pending_grant_handles;
struct xen_blkbk {
pending_req_t *pending_reqs;
struct list_head pending_free;
spinlock_t pending_free_lock;
wait_queue_head_t pending_free_wq;
struct page **pending_pages;
grant_handle_t *pending_grant_handles;
};
static struct xen_blkbk *blkbk;
static inline int vaddr_pagenr(pending_req_t *req, int seg)
{
return (req - pending_reqs) * BLKIF_MAX_SEGMENTS_PER_REQUEST + seg;
return (req - blkbk->pending_reqs) * BLKIF_MAX_SEGMENTS_PER_REQUEST + seg;
}
#define pending_page(req, seg) pending_pages[vaddr_pagenr(req, seg)]
static inline unsigned long vaddr(pending_req_t *req, int seg)
{
unsigned long pfn = page_to_pfn(pending_page(req, seg));
unsigned long pfn = page_to_pfn(blkbk->pending_page(req, seg));
return (unsigned long)pfn_to_kaddr(pfn);
}
#define pending_handle(_req, _seg) \
(pending_grant_handles[vaddr_pagenr(_req, _seg)])
(blkbk->pending_grant_handles[vaddr_pagenr(_req, _seg)])
static int do_block_io_op(blkif_t *blkif);
@ -126,12 +129,12 @@ static pending_req_t* alloc_req(void)
pending_req_t *req = NULL;
unsigned long flags;
spin_lock_irqsave(&pending_free_lock, flags);
if (!list_empty(&pending_free)) {
req = list_entry(pending_free.next, pending_req_t, free_list);
spin_lock_irqsave(&blkbk->pending_free_lock, flags);
if (!list_empty(&blkbk->pending_free)) {
req = list_entry(blkbk->pending_free.next, pending_req_t, free_list);
list_del(&req->free_list);
}
spin_unlock_irqrestore(&pending_free_lock, flags);
spin_unlock_irqrestore(&blkbk->pending_free_lock, flags);
return req;
}
@ -140,12 +143,12 @@ static void free_req(pending_req_t *req)
unsigned long flags;
int was_empty;
spin_lock_irqsave(&pending_free_lock, flags);
was_empty = list_empty(&pending_free);
list_add(&req->free_list, &pending_free);
spin_unlock_irqrestore(&pending_free_lock, flags);
spin_lock_irqsave(&blkbk->pending_free_lock, flags);
was_empty = list_empty(&blkbk->pending_free);
list_add(&req->free_list, &blkbk->pending_free);
spin_unlock_irqrestore(&blkbk->pending_free_lock, flags);
if (was_empty)
wake_up(&pending_free_wq);
wake_up(&blkbk->pending_free_wq);
}
static void unplug_queue(blkif_t *blkif)
@ -226,8 +229,8 @@ int blkif_schedule(void *arg)
blkif->wq,
blkif->waiting_reqs || kthread_should_stop());
wait_event_interruptible(
pending_free_wq,
!list_empty(&pending_free) || kthread_should_stop());
blkbk->pending_free_wq,
!list_empty(&blkbk->pending_free) || kthread_should_stop());
blkif->waiting_reqs = 0;
smp_mb(); /* clear flag *before* checking for work */
@ -466,7 +469,7 @@ static void dispatch_rw_block_io(blkif_t *blkif,
continue;
set_phys_to_machine(
page_to_pfn(pending_page(pending_req, i)),
page_to_pfn(blkbk->pending_page(pending_req, i)),
FOREIGN_FRAME(map[i].dev_bus_addr >> PAGE_SHIFT));
seg[i].buf = map[i].dev_bus_addr |
(req->seg[i].first_sect << 9);
@ -497,7 +500,7 @@ static void dispatch_rw_block_io(blkif_t *blkif,
while ((bio == NULL) ||
(bio_add_page(bio,
pending_page(pending_req, i),
blkbk->pending_page(pending_req, i),
seg[i].nsec << 9,
seg[i].buf & ~PAGE_MASK) == 0)) {
if (bio) {
@ -624,31 +627,40 @@ static int __init blkif_init(void)
if (!xen_pv_domain())
return -ENODEV;
blkbk = (struct xen_blkbk *)vmalloc(sizeof(struct xen_blkbk));
if (!blkbk) {
printk(KERN_ALERT "%s: out of memory!\n", __func__);
return -ENOMEM;
}
mmap_pages = blkif_reqs * BLKIF_MAX_SEGMENTS_PER_REQUEST;
pending_reqs = kmalloc(sizeof(pending_reqs[0]) *
blkbk->pending_reqs = kmalloc(sizeof(blkbk->pending_reqs[0]) *
blkif_reqs, GFP_KERNEL);
pending_grant_handles = kmalloc(sizeof(pending_grant_handles[0]) *
blkbk->pending_grant_handles = kmalloc(sizeof(blkbk->pending_grant_handles[0]) *
mmap_pages, GFP_KERNEL);
pending_pages = alloc_empty_pages_and_pagevec(mmap_pages);
blkbk->pending_pages = alloc_empty_pages_and_pagevec(mmap_pages);
if (!pending_reqs || !pending_grant_handles || !pending_pages) {
if (!blkbk->pending_reqs || !blkbk->pending_grant_handles || !blkbk->pending_pages) {
rc = -ENOMEM;
goto out_of_memory;
}
for (i = 0; i < mmap_pages; i++)
pending_grant_handles[i] = BLKBACK_INVALID_HANDLE;
blkbk->pending_grant_handles[i] = BLKBACK_INVALID_HANDLE;
rc = blkif_interface_init();
if (rc)
goto failed_init;
memset(pending_reqs, 0, sizeof(pending_reqs));
INIT_LIST_HEAD(&pending_free);
memset(blkbk->pending_reqs, 0, sizeof(blkbk->pending_reqs));
INIT_LIST_HEAD(&blkbk->pending_free);
spin_lock_init(&blkbk->pending_free_lock);
init_waitqueue_head(&blkbk->pending_free_wq);
for (i = 0; i < blkif_reqs; i++)
list_add_tail(&pending_reqs[i].free_list, &pending_free);
list_add_tail(&blkbk->pending_reqs[i].free_list, &blkbk->pending_free);
rc = blkif_xenbus_init();
if (rc)
@ -659,9 +671,11 @@ static int __init blkif_init(void)
out_of_memory:
printk(KERN_ERR "%s: out of memory\n", __func__);
failed_init:
kfree(pending_reqs);
kfree(pending_grant_handles);
free_empty_pages_and_pagevec(pending_pages, mmap_pages);
kfree(blkbk->pending_reqs);
kfree(blkbk->pending_grant_handles);
free_empty_pages_and_pagevec(blkbk->pending_pages, mmap_pages);
vfree(blkbk);
blkbk = NULL;
return rc;
}