diff options
| -rw-r--r-- | mm/swapfile.c | 146 |
1 files changed, 65 insertions, 81 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index c46c83d6aab0..85ff603385c3 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1456,7 +1456,6 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags) int i, prev; int error; union swap_header *swap_header = NULL; - int swap_header_version; unsigned int nr_good_pages = 0; int nr_extents = 0; sector_t span; @@ -1553,101 +1552,86 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags) error = PTR_ERR(page); goto bad_swap; } - kmap(page); - swap_header = page_address(page); + swap_header = kmap(page); - if (!memcmp("SWAP-SPACE",swap_header->magic.magic,10)) - swap_header_version = 1; - else if (!memcmp("SWAPSPACE2",swap_header->magic.magic,10)) - swap_header_version = 2; - else { + if (memcmp("SWAPSPACE2", swap_header->magic.magic, 10)) { printk(KERN_ERR "Unable to find swap-space signature\n"); error = -EINVAL; goto bad_swap; } - switch (swap_header_version) { - case 1: - printk(KERN_ERR "version 0 swap is no longer supported. " - "Use mkswap -v1 %s\n", name); + /* swap partition endianess hack... */ + if (swab32(swap_header->info.version) == 1) { + swab32s(&swap_header->info.version); + swab32s(&swap_header->info.last_page); + swab32s(&swap_header->info.nr_badpages); + for (i = 0; i < swap_header->info.nr_badpages; i++) + swab32s(&swap_header->info.badpages[i]); + } + /* Check the swap header's sub-version */ + if (swap_header->info.version != 1) { + printk(KERN_WARNING + "Unable to handle swap header version %d\n", + swap_header->info.version); error = -EINVAL; goto bad_swap; - case 2: - /* swap partition endianess hack... */ - if (swab32(swap_header->info.version) == 1) { - swab32s(&swap_header->info.version); - swab32s(&swap_header->info.last_page); - swab32s(&swap_header->info.nr_badpages); - for (i = 0; i < swap_header->info.nr_badpages; i++) - swab32s(&swap_header->info.badpages[i]); - } - /* Check the swap header's sub-version and the size of - the swap file and bad block lists */ - if (swap_header->info.version != 1) { - printk(KERN_WARNING - "Unable to handle swap header version %d\n", - swap_header->info.version); - error = -EINVAL; - goto bad_swap; - } + } - p->lowest_bit = 1; - p->cluster_next = 1; + p->lowest_bit = 1; + p->cluster_next = 1; - /* - * Find out how many pages are allowed for a single swap - * device. There are two limiting factors: 1) the number of - * bits for the swap offset in the swp_entry_t type and - * 2) the number of bits in the a swap pte as defined by - * the different architectures. In order to find the - * largest possible bit mask a swap entry with swap type 0 - * and swap offset ~0UL is created, encoded to a swap pte, - * decoded to a swp_entry_t again and finally the swap - * offset is extracted. This will mask all the bits from - * the initial ~0UL mask that can't be encoded in either - * the swp_entry_t or the architecture definition of a - * 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; - p->highest_bit = maxpages - 1; + /* + * Find out how many pages are allowed for a single swap + * device. There are two limiting factors: 1) the number of + * bits for the swap offset in the swp_entry_t type and + * 2) the number of bits in the a swap pte as defined by + * the different architectures. In order to find the + * largest possible bit mask a swap entry with swap type 0 + * and swap offset ~0UL is created, encoded to a swap pte, + * decoded to a swp_entry_t again and finally the swap + * offset is extracted. This will mask all the bits from + * the initial ~0UL mask that can't be encoded in either + * the swp_entry_t or the architecture definition of a + * 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; + p->highest_bit = maxpages - 1; - error = -EINVAL; - if (!maxpages) - goto bad_swap; - if (swapfilepages && maxpages > swapfilepages) { - printk(KERN_WARNING - "Swap area shorter than signature indicates\n"); - goto bad_swap; - } - if (swap_header->info.nr_badpages && S_ISREG(inode->i_mode)) - goto bad_swap; - if (swap_header->info.nr_badpages > MAX_SWAP_BADPAGES) - goto bad_swap; + error = -EINVAL; + if (!maxpages) + goto bad_swap; + if (swapfilepages && maxpages > swapfilepages) { + printk(KERN_WARNING + "Swap area shorter than signature indicates\n"); + goto bad_swap; + } + if (swap_header->info.nr_badpages && S_ISREG(inode->i_mode)) + goto bad_swap; + if (swap_header->info.nr_badpages > MAX_SWAP_BADPAGES) + goto bad_swap; - /* OK, set up the swap map and apply the bad block list */ - swap_map = vmalloc(maxpages * sizeof(short)); - if (!swap_map) { - error = -ENOMEM; - goto bad_swap; - } + /* OK, set up the swap map and apply the bad block list */ + swap_map = vmalloc(maxpages * sizeof(short)); + if (!swap_map) { + error = -ENOMEM; + goto bad_swap; + } - error = 0; - memset(swap_map, 0, maxpages * sizeof(short)); - 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) - error = -EINVAL; - else - swap_map[page_nr] = SWAP_MAP_BAD; - } - nr_good_pages = swap_header->info.last_page - - swap_header->info.nr_badpages - - 1 /* header page */; - if (error) + memset(swap_map, 0, maxpages * sizeof(short)); + 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) { + error = -EINVAL; goto bad_swap; + } + swap_map[page_nr] = SWAP_MAP_BAD; } + 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; |