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>

diff --git a/drivers/xen/blkback/blkback.c b/drivers/xen/blkback/blkback.c
index 7c9421c..c08875b 100644 (file)
--- a/drivers/xen/blkback/blkback.c
+++ b/drivers/xen/blkback/blkback.c
@@ -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;
 }