KVM: x86 emulator: add and use new callbacks set_idt(), set_gdt()

[pandora-kernel.git] / mm / swapfile.c

diff --git a/mm/swapfile.c b/mm/swapfile.c
index aafcf36..8c6b3ce 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -94,39 +94,6 @@ __try_to_reclaim_swap(struct swap_info_struct *si, unsigned long offset)
        return ret;
 }
 
-/*
- * We need this because the bdev->unplug_fn can sleep and we cannot
- * hold swap_lock while calling the unplug_fn. And swap_lock
- * cannot be turned into a mutex.
- */
-static DECLARE_RWSEM(swap_unplug_sem);
-
-void swap_unplug_io_fn(struct backing_dev_info *unused_bdi, struct page *page)
-{
-       swp_entry_t entry;
-
-       down_read(&swap_unplug_sem);
-       entry.val = page_private(page);
-       if (PageSwapCache(page)) {
-               struct block_device *bdev = swap_info[swp_type(entry)]->bdev;
-               struct backing_dev_info *bdi;
-
-               /*
-                * If the page is removed from swapcache from under us (with a
-                * racy try_to_unuse/swapoff) we need an additional reference
-                * count to avoid reading garbage from page_private(page) above.
-                * If the WARN_ON triggers during a swapoff it maybe the race
-                * condition and it's harmless. However if it triggers without
-                * swapoff it signals a problem.
-                */
-               WARN_ON(page_count(page) <= 1);
-
-               bdi = bdev->bd_inode->i_mapping->backing_dev_info;
-               blk_run_backing_dev(bdi, page);
-       }
-       up_read(&swap_unplug_sem);
-}
-
 /*
  * swapon tell device that all the old swap contents can be discarded,
  * to allow the swap device to optimize its wear-levelling.
@@ -880,7 +847,7 @@ unsigned int count_swap_pages(int type, int free)
 static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
                unsigned long addr, swp_entry_t entry, struct page *page)
 {
-       struct mem_cgroup *ptr = NULL;
+       struct mem_cgroup *ptr;
        spinlock_t *ptl;
        pte_t *pte;
        int ret = 1;
@@ -1662,10 +1629,6 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
                goto out_dput;
        }
 
-       /* wait for any unplug function to finish */
-       down_write(&swap_unplug_sem);
-       up_write(&swap_unplug_sem);
-
        destroy_swap_extents(p);
        if (p->flags & SWP_CONTINUED)
                free_swap_count_continuations(p);
@@ -2088,7 +2051,6 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 
        p->swap_file = swap_file;
        mapping = swap_file->f_mapping;
-       inode = mapping->host;
 
        for (i = 0; i < nr_swapfiles; i++) {
                struct swap_info_struct *q = swap_info[i];
@@ -2101,6 +2063,8 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
                }
        }
 
+       inode = mapping->host;
+       /* If S_ISREG(inode->i_mode) will do mutex_lock(&inode->i_mutex); */
        error = claim_swapfile(p, inode);
        if (unlikely(error))
                goto bad_swap;
@@ -2187,8 +2151,10 @@ bad_swap:
        spin_unlock(&swap_lock);
        vfree(swap_map);
        if (swap_file) {
-               if (inode && S_ISREG(inode->i_mode))
+               if (inode && S_ISREG(inode->i_mode)) {
                        mutex_unlock(&inode->i_mutex);
+                       inode = NULL;
+               }
                filp_close(swap_file, NULL);
        }
 out: