diff options
| -rw-r--r-- | mm/swapfile.c | 83 |
1 files changed, 54 insertions, 29 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index 10f2b33805f..a0f39f9dc5a 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1991,6 +1991,54 @@ static unsigned long read_swap_header(struct swap_info_struct *p, return maxpages; } +static int setup_swap_map_and_extents(struct swap_info_struct *p, + union swap_header *swap_header, + unsigned char *swap_map, + unsigned long maxpages, + sector_t *span) +{ + int i; + int error; + unsigned int nr_good_pages; + int nr_extents; + + nr_good_pages = maxpages - 1; /* omit header page */ + + for (i = 0; i < swap_header->info.nr_badpages; i++) { + 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; + } + if (page_nr < maxpages) { + swap_map[page_nr] = SWAP_MAP_BAD; + nr_good_pages--; + } + } + + if (nr_good_pages) { + swap_map[0] = SWAP_MAP_BAD; + p->max = maxpages; + p->pages = nr_good_pages; + nr_extents = setup_swap_extents(p, span); + if (nr_extents < 0) { + error = nr_extents; + goto bad_swap; + } + nr_good_pages = p->pages; + } + if (!nr_good_pages) { + printk(KERN_WARNING "Empty swap-file\n"); + error = -EINVAL; + goto bad_swap; + } + + return nr_extents; + +bad_swap: + return error; +} + SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) { struct swap_info_struct *p; @@ -2001,7 +2049,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) int error; union swap_header *swap_header; unsigned int nr_good_pages; - int nr_extents = 0; + int nr_extents; sector_t span; unsigned long maxpages; unsigned char *swap_map = NULL; @@ -2078,36 +2126,13 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) if (error) goto bad_swap; - nr_good_pages = maxpages - 1; /* omit header page */ - - for (i = 0; i < swap_header->info.nr_badpages; i++) { - 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; - } - if (page_nr < maxpages) { - swap_map[page_nr] = SWAP_MAP_BAD; - nr_good_pages--; - } - } - - if (nr_good_pages) { - swap_map[0] = SWAP_MAP_BAD; - p->max = maxpages; - p->pages = nr_good_pages; - nr_extents = setup_swap_extents(p, &span); - if (nr_extents < 0) { - error = nr_extents; - goto bad_swap; - } - nr_good_pages = p->pages; - } - if (!nr_good_pages) { - printk(KERN_WARNING "Empty swap-file\n"); - error = -EINVAL; + nr_extents = setup_swap_map_and_extents(p, swap_header, swap_map, + maxpages, &span); + if (unlikely(nr_extents < 0)) { + error = nr_extents; goto bad_swap; } + nr_good_pages = p->pages; if (p->bdev) { if (blk_queue_nonrot(bdev_get_queue(p->bdev))) { |