diff options
Diffstat (limited to 'mm/swapfile.c')
| -rw-r--r-- | mm/swapfile.c | 46 |
1 files changed, 6 insertions, 40 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index aafcf3611b3..8c6b3ce38f0 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -95,39 +95,6 @@ __try_to_reclaim_swap(struct swap_info_struct *si, unsigned long offset) } /* - * 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: |