diff options
| -rw-r--r-- | mm/swap_state.c | 53 |
1 files changed, 19 insertions, 34 deletions
diff --git a/mm/swap_state.c b/mm/swap_state.c index 18fce3613e5a..c75eda2c9cc5 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -64,10 +64,10 @@ void show_swap_cache_info(void) } /* - * __add_to_swap_cache resembles add_to_page_cache on swapper_space, + * add_to_swap_cache resembles add_to_page_cache on swapper_space, * but sets SwapCache flag and private instead of mapping and index. */ -static int __add_to_swap_cache(struct page *page, swp_entry_t entry, +static int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask) { int error; @@ -94,28 +94,6 @@ static int __add_to_swap_cache(struct page *page, swp_entry_t entry, return error; } -static int add_to_swap_cache(struct page *page, swp_entry_t entry, - gfp_t gfp_mask) -{ - int error; - - BUG_ON(PageLocked(page)); - if (!swap_duplicate(entry)) - return -ENOENT; - - SetPageLocked(page); - error = __add_to_swap_cache(page, entry, gfp_mask & GFP_KERNEL); - /* - * Anon pages are already on the LRU, we don't run lru_cache_add here. - */ - if (error) { - ClearPageLocked(page); - swap_free(entry); - return error; - } - return 0; -} - /* * This must be called only on pages that have * been verified to be in the swap cache. @@ -165,7 +143,7 @@ int add_to_swap(struct page * page, gfp_t gfp_mask) /* * Add it to the swap cache and mark it dirty */ - err = __add_to_swap_cache(page, entry, + err = add_to_swap_cache(page, entry, gfp_mask|__GFP_NOMEMALLOC|__GFP_NOWARN); switch (err) { @@ -210,7 +188,7 @@ void delete_from_swap_cache(struct page *page) */ int move_to_swap_cache(struct page *page, swp_entry_t entry) { - int err = __add_to_swap_cache(page, entry, GFP_ATOMIC); + int err = add_to_swap_cache(page, entry, GFP_ATOMIC); if (!err) { remove_from_page_cache(page); page_cache_release(page); /* pagecache ref */ @@ -335,16 +313,21 @@ struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, } /* + * Swap entry may have been freed since our caller observed it. + */ + if (!swap_duplicate(entry)) + break; + + /* * Associate the page with swap entry in the swap cache. - * May fail (-ENOENT) if swap entry has been freed since - * our caller observed it. May fail (-EEXIST) if there - * is already a page associated with this entry in the - * swap cache: added by a racing read_swap_cache_async, - * or by try_to_swap_out (or shmem_writepage) re-using - * the just freed swap entry for an existing page. + * May fail (-EEXIST) if there is already a page associated + * with this entry in the swap cache: added by a racing + * read_swap_cache_async, or add_to_swap or shmem_writepage + * re-using the just freed swap entry for an existing page. * May fail (-ENOMEM) if radix-tree node allocation failed. */ - err = add_to_swap_cache(new_page, entry, gfp_mask); + SetPageLocked(new_page); + err = add_to_swap_cache(new_page, entry, gfp_mask & GFP_KERNEL); if (!err) { /* * Initiate read into locked page and return. @@ -353,7 +336,9 @@ struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask, swap_readpage(NULL, new_page); return new_page; } - } while (err != -ENOENT && err != -ENOMEM); + ClearPageLocked(new_page); + swap_free(entry); + } while (err != -ENOMEM); if (new_page) page_cache_release(new_page); |