diff options
Diffstat (limited to 'mm/swapfile.c')
| -rw-r--r-- | mm/swapfile.c | 44 |
1 files changed, 34 insertions, 10 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index bf91dc9e7a79..3074b02eaa09 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1328,6 +1328,13 @@ int page_swapcount(struct page *page) return count; } +int __swap_count(struct swap_info_struct *si, swp_entry_t entry) +{ + pgoff_t offset = swp_offset(entry); + + return swap_count(si->swap_map[offset]); +} + static int swap_swapcount(struct swap_info_struct *si, swp_entry_t entry) { int count = 0; @@ -2869,6 +2876,7 @@ static struct swap_info_struct *alloc_swap_info(void) p->flags = SWP_USED; spin_unlock(&swap_lock); spin_lock_init(&p->lock); + spin_lock_init(&p->cont_lock); return p; } @@ -3168,6 +3176,9 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) if (bdi_cap_stable_pages_required(inode_to_bdi(inode))) p->flags |= SWP_STABLE_WRITES; + if (bdi_cap_synchronous_io(inode_to_bdi(inode))) + p->flags |= SWP_SYNCHRONOUS_IO; + if (p->bdev && blk_queue_nonrot(bdev_get_queue(p->bdev))) { int cpu; unsigned long ci, nr_cluster; @@ -3451,10 +3462,15 @@ int swapcache_prepare(swp_entry_t entry) return __swap_duplicate(entry, SWAP_HAS_CACHE); } +struct swap_info_struct *swp_swap_info(swp_entry_t entry) +{ + return swap_info[swp_type(entry)]; +} + struct swap_info_struct *page_swap_info(struct page *page) { - swp_entry_t swap = { .val = page_private(page) }; - return swap_info[swp_type(swap)]; + swp_entry_t entry = { .val = page_private(page) }; + return swp_swap_info(entry); } /* @@ -3462,7 +3478,6 @@ struct swap_info_struct *page_swap_info(struct page *page) */ struct address_space *__page_file_mapping(struct page *page) { - VM_BUG_ON_PAGE(!PageSwapCache(page), page); return page_swap_info(page)->swap_file->f_mapping; } EXPORT_SYMBOL_GPL(__page_file_mapping); @@ -3470,7 +3485,6 @@ EXPORT_SYMBOL_GPL(__page_file_mapping); pgoff_t __page_file_index(struct page *page) { swp_entry_t swap = { .val = page_private(page) }; - VM_BUG_ON_PAGE(!PageSwapCache(page), page); return swp_offset(swap); } EXPORT_SYMBOL_GPL(__page_file_index); @@ -3545,6 +3559,7 @@ int add_swap_count_continuation(swp_entry_t entry, gfp_t gfp_mask) head = vmalloc_to_page(si->swap_map + offset); offset &= ~PAGE_MASK; + spin_lock(&si->cont_lock); /* * Page allocation does not initialize the page's lru field, * but it does always reset its private field. @@ -3564,7 +3579,7 @@ int add_swap_count_continuation(swp_entry_t entry, gfp_t gfp_mask) * a continuation page, free our allocation and use this one. */ if (!(count & COUNT_CONTINUED)) - goto out; + goto out_unlock_cont; map = kmap_atomic(list_page) + offset; count = *map; @@ -3575,11 +3590,13 @@ int add_swap_count_continuation(swp_entry_t entry, gfp_t gfp_mask) * free our allocation and use this one. */ if ((count & ~COUNT_CONTINUED) != SWAP_CONT_MAX) - goto out; + goto out_unlock_cont; } list_add_tail(&page->lru, &head->lru); page = NULL; /* now it's attached, don't free it */ +out_unlock_cont: + spin_unlock(&si->cont_lock); out: unlock_cluster(ci); spin_unlock(&si->lock); @@ -3604,6 +3621,7 @@ static bool swap_count_continued(struct swap_info_struct *si, struct page *head; struct page *page; unsigned char *map; + bool ret; head = vmalloc_to_page(si->swap_map + offset); if (page_private(head) != SWP_CONTINUED) { @@ -3611,6 +3629,7 @@ static bool swap_count_continued(struct swap_info_struct *si, return false; /* need to add count continuation */ } + spin_lock(&si->cont_lock); offset &= ~PAGE_MASK; page = list_entry(head->lru.next, struct page, lru); map = kmap_atomic(page) + offset; @@ -3631,8 +3650,10 @@ static bool swap_count_continued(struct swap_info_struct *si, if (*map == SWAP_CONT_MAX) { kunmap_atomic(map); page = list_entry(page->lru.next, struct page, lru); - if (page == head) - return false; /* add count continuation */ + if (page == head) { + ret = false; /* add count continuation */ + goto out; + } map = kmap_atomic(page) + offset; init_map: *map = 0; /* we didn't zero the page */ } @@ -3645,7 +3666,7 @@ init_map: *map = 0; /* we didn't zero the page */ kunmap_atomic(map); page = list_entry(page->lru.prev, struct page, lru); } - return true; /* incremented */ + ret = true; /* incremented */ } else { /* decrementing */ /* @@ -3671,8 +3692,11 @@ init_map: *map = 0; /* we didn't zero the page */ kunmap_atomic(map); page = list_entry(page->lru.prev, struct page, lru); } - return count == COUNT_CONTINUED; + ret = count == COUNT_CONTINUED; } +out: + spin_unlock(&si->cont_lock); + return ret; } /* |