swapfile: remove v0 SWAP-SPACE message
The kernel has not supported v0 SWAP-SPACE since 2.5.22: I think we can now safely drop its "version 0 swap is no longer supported" message - just say "Unable to find swap-space signature" as usual. This removes one level of indentation from a stretch of sys_swapon(). I'd have liked to be specific, saying "Unable to find SWAPSPACE2 signature", but it's just too confusing that the version 1 signature shows the number 2. Irrelevant nearby cleanup: kmap(page) already gives page_address(page). Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Hugh Dickins
Linus Torvalds
parent
886bb7e9c3
commit
81e3397127
1 changed files with 68 additions and 84 deletions
152
mm/swapfile.c
152
mm/swapfile.c
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@ -1456,7 +1456,6 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
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int i, prev;
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int error;
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union swap_header *swap_header = NULL;
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int swap_header_version;
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unsigned int nr_good_pages = 0;
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int nr_extents = 0;
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sector_t span;
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@ -1553,101 +1552,86 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
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error = PTR_ERR(page);
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goto bad_swap;
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}
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kmap(page);
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swap_header = page_address(page);
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swap_header = kmap(page);
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if (!memcmp("SWAP-SPACE",swap_header->magic.magic,10))
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swap_header_version = 1;
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else if (!memcmp("SWAPSPACE2",swap_header->magic.magic,10))
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swap_header_version = 2;
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else {
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if (memcmp("SWAPSPACE2", swap_header->magic.magic, 10)) {
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printk(KERN_ERR "Unable to find swap-space signature\n");
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error = -EINVAL;
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goto bad_swap;
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}
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switch (swap_header_version) {
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case 1:
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printk(KERN_ERR "version 0 swap is no longer supported. "
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"Use mkswap -v1 %s\n", name);
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/* swap partition endianess hack... */
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if (swab32(swap_header->info.version) == 1) {
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swab32s(&swap_header->info.version);
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swab32s(&swap_header->info.last_page);
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swab32s(&swap_header->info.nr_badpages);
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for (i = 0; i < swap_header->info.nr_badpages; i++)
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swab32s(&swap_header->info.badpages[i]);
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}
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/* Check the swap header's sub-version */
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if (swap_header->info.version != 1) {
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printk(KERN_WARNING
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"Unable to handle swap header version %d\n",
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swap_header->info.version);
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error = -EINVAL;
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goto bad_swap;
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case 2:
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/* swap partition endianess hack... */
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if (swab32(swap_header->info.version) == 1) {
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swab32s(&swap_header->info.version);
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swab32s(&swap_header->info.last_page);
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swab32s(&swap_header->info.nr_badpages);
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for (i = 0; i < swap_header->info.nr_badpages; i++)
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swab32s(&swap_header->info.badpages[i]);
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}
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/* Check the swap header's sub-version and the size of
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the swap file and bad block lists */
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if (swap_header->info.version != 1) {
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printk(KERN_WARNING
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"Unable to handle swap header version %d\n",
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swap_header->info.version);
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}
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p->lowest_bit = 1;
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p->cluster_next = 1;
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/*
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* Find out how many pages are allowed for a single swap
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* device. There are two limiting factors: 1) the number of
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* bits for the swap offset in the swp_entry_t type and
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* 2) the number of bits in the a swap pte as defined by
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* the different architectures. In order to find the
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* largest possible bit mask a swap entry with swap type 0
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* and swap offset ~0UL is created, encoded to a swap pte,
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* decoded to a swp_entry_t again and finally the swap
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* offset is extracted. This will mask all the bits from
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* the initial ~0UL mask that can't be encoded in either
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* the swp_entry_t or the architecture definition of a
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* swap pte.
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*/
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maxpages = swp_offset(pte_to_swp_entry(
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swp_entry_to_pte(swp_entry(0, ~0UL)))) - 1;
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if (maxpages > swap_header->info.last_page)
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maxpages = swap_header->info.last_page;
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p->highest_bit = maxpages - 1;
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error = -EINVAL;
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if (!maxpages)
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goto bad_swap;
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if (swapfilepages && maxpages > swapfilepages) {
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printk(KERN_WARNING
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"Swap area shorter than signature indicates\n");
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goto bad_swap;
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}
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if (swap_header->info.nr_badpages && S_ISREG(inode->i_mode))
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goto bad_swap;
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if (swap_header->info.nr_badpages > MAX_SWAP_BADPAGES)
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goto bad_swap;
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/* OK, set up the swap map and apply the bad block list */
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swap_map = vmalloc(maxpages * sizeof(short));
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if (!swap_map) {
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error = -ENOMEM;
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goto bad_swap;
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}
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memset(swap_map, 0, maxpages * sizeof(short));
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for (i = 0; i < swap_header->info.nr_badpages; i++) {
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int page_nr = swap_header->info.badpages[i];
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if (page_nr <= 0 || page_nr >= swap_header->info.last_page) {
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error = -EINVAL;
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goto bad_swap;
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}
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p->lowest_bit = 1;
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p->cluster_next = 1;
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/*
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* Find out how many pages are allowed for a single swap
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* device. There are two limiting factors: 1) the number of
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* bits for the swap offset in the swp_entry_t type and
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* 2) the number of bits in the a swap pte as defined by
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* the different architectures. In order to find the
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* largest possible bit mask a swap entry with swap type 0
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* and swap offset ~0UL is created, encoded to a swap pte,
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* decoded to a swp_entry_t again and finally the swap
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* offset is extracted. This will mask all the bits from
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* the initial ~0UL mask that can't be encoded in either
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* the swp_entry_t or the architecture definition of a
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* swap pte.
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*/
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maxpages = swp_offset(pte_to_swp_entry(swp_entry_to_pte(swp_entry(0,~0UL)))) - 1;
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if (maxpages > swap_header->info.last_page)
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maxpages = swap_header->info.last_page;
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p->highest_bit = maxpages - 1;
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error = -EINVAL;
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if (!maxpages)
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goto bad_swap;
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if (swapfilepages && maxpages > swapfilepages) {
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printk(KERN_WARNING
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"Swap area shorter than signature indicates\n");
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goto bad_swap;
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}
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if (swap_header->info.nr_badpages && S_ISREG(inode->i_mode))
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goto bad_swap;
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if (swap_header->info.nr_badpages > MAX_SWAP_BADPAGES)
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goto bad_swap;
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/* OK, set up the swap map and apply the bad block list */
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swap_map = vmalloc(maxpages * sizeof(short));
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if (!swap_map) {
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error = -ENOMEM;
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goto bad_swap;
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}
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error = 0;
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memset(swap_map, 0, maxpages * sizeof(short));
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for (i = 0; i < swap_header->info.nr_badpages; i++) {
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int page_nr = swap_header->info.badpages[i];
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if (page_nr <= 0 || page_nr >= swap_header->info.last_page)
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error = -EINVAL;
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else
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swap_map[page_nr] = SWAP_MAP_BAD;
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}
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nr_good_pages = swap_header->info.last_page -
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swap_header->info.nr_badpages -
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1 /* header page */;
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if (error)
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goto bad_swap;
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swap_map[page_nr] = SWAP_MAP_BAD;
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}
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nr_good_pages = swap_header->info.last_page -
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swap_header->info.nr_badpages -
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1 /* header page */;
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if (nr_good_pages) {
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swap_map[0] = SWAP_MAP_BAD;
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