diff options
Diffstat (limited to 'mm/swapfile.c')
| -rw-r--r-- | mm/swapfile.c | 71 |
1 files changed, 56 insertions, 15 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index 6c0585b1641..6cd0a8f90dc 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -723,6 +723,37 @@ int free_swap_and_cache(swp_entry_t entry) return p != NULL; } +#ifdef CONFIG_CGROUP_MEM_RES_CTLR +/** + * mem_cgroup_count_swap_user - count the user of a swap entry + * @ent: the swap entry to be checked + * @pagep: the pointer for the swap cache page of the entry to be stored + * + * Returns the number of the user of the swap entry. The number is valid only + * for swaps of anonymous pages. + * If the entry is found on swap cache, the page is stored to pagep with + * refcount of it being incremented. + */ +int mem_cgroup_count_swap_user(swp_entry_t ent, struct page **pagep) +{ + struct page *page; + struct swap_info_struct *p; + int count = 0; + + page = find_get_page(&swapper_space, ent.val); + if (page) + count += page_mapcount(page); + p = swap_info_get(ent); + if (p) { + count += swap_count(p->swap_map[swp_offset(ent)]); + spin_unlock(&swap_lock); + } + + *pagep = page; + return count; +} +#endif + #ifdef CONFIG_HIBERNATION /* * Find the swap type that corresponds to given device (if any). @@ -840,7 +871,8 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, goto out; } - inc_mm_counter(vma->vm_mm, anon_rss); + dec_mm_counter(vma->vm_mm, MM_SWAPENTS); + inc_mm_counter(vma->vm_mm, MM_ANONPAGES); get_page(page); set_pte_at(vma->vm_mm, addr, pte, pte_mkold(mk_pte(page, vma->vm_page_prot))); @@ -1759,11 +1791,11 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) unsigned int type; int i, prev; int error; - union swap_header *swap_header = NULL; - unsigned int nr_good_pages = 0; + union swap_header *swap_header; + unsigned int nr_good_pages; int nr_extents = 0; sector_t span; - unsigned long maxpages = 1; + unsigned long maxpages; unsigned long swapfilepages; unsigned char *swap_map = NULL; struct page *page = NULL; @@ -1922,9 +1954,13 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) * swap pte. */ maxpages = swp_offset(pte_to_swp_entry( - swp_entry_to_pte(swp_entry(0, ~0UL)))) - 1; - if (maxpages > swap_header->info.last_page) - maxpages = swap_header->info.last_page; + swp_entry_to_pte(swp_entry(0, ~0UL)))) + 1; + if (maxpages > swap_header->info.last_page) { + maxpages = swap_header->info.last_page + 1; + /* p->max is an unsigned int: don't overflow it */ + if ((unsigned int)maxpages == 0) + maxpages = UINT_MAX; + } p->highest_bit = maxpages - 1; error = -EINVAL; @@ -1948,23 +1984,24 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) } memset(swap_map, 0, maxpages); + nr_good_pages = maxpages - 1; /* omit header page */ + for (i = 0; i < swap_header->info.nr_badpages; i++) { - int page_nr = swap_header->info.badpages[i]; - if (page_nr <= 0 || page_nr >= swap_header->info.last_page) { + unsigned int page_nr = swap_header->info.badpages[i]; + if (page_nr == 0 || page_nr > swap_header->info.last_page) { error = -EINVAL; goto bad_swap; } - swap_map[page_nr] = SWAP_MAP_BAD; + if (page_nr < maxpages) { + swap_map[page_nr] = SWAP_MAP_BAD; + nr_good_pages--; + } } error = swap_cgroup_swapon(type, maxpages); if (error) goto bad_swap; - nr_good_pages = swap_header->info.last_page - - swap_header->info.nr_badpages - - 1 /* header page */; - if (nr_good_pages) { swap_map[0] = SWAP_MAP_BAD; p->max = maxpages; @@ -2155,7 +2192,11 @@ void swap_shmem_alloc(swp_entry_t entry) } /* - * increase reference count of swap entry by 1. + * Increase reference count of swap entry by 1. + * Returns 0 for success, or -ENOMEM if a swap_count_continuation is required + * but could not be atomically allocated. Returns 0, just as if it succeeded, + * if __swap_duplicate() fails for another reason (-EINVAL or -ENOENT), which + * might occur if a page table entry has got corrupted. */ int swap_duplicate(swp_entry_t entry) { |