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authorHugh Dickins <hugh@veritas.com>2005-09-03 15:54:32 -0700
committerLinus Torvalds <torvalds@evo.osdl.org>2005-09-05 00:05:40 -0700
commite2244ec2efa4ee1edf391d0001d314933e2b2974 (patch)
treec9e43f9b6e11ce41d976025c6f9d94c273521132 /mm
parentb0d9bcd4bb79a7834f8492f2ae5c2655a551f23d (diff)
downloadlinux-sh-e2244ec2efa4ee1edf391d0001d314933e2b2974.tar.gz
[PATCH] swap: correct swapfile nr_good_pages
If a regular swapfile lies on a filesystem whose blocksize is less than PAGE_SIZE, then setup_swap_extents may have to cut the number of usable swap pages; but sys_swapon's nr_good_pages was not expecting that. Also, setup_swap_extents takes no account of badpages listed in the swap header: not worth doing so, but ensure nr_badpages is 0 for a regular swapfile. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/swapfile.c25
1 files changed, 16 insertions, 9 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 9f46d83b4ece..5ac5333f37a0 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1008,8 +1008,9 @@ reprobe:
}
ret = 0;
if (page_no == 0)
- ret = -EINVAL;
+ page_no = 1; /* force Empty message */
sis->max = page_no;
+ sis->pages = page_no - 1;
sis->highest_bit = page_no - 1;
done:
sis->curr_swap_extent = list_entry(sis->extent_list.prev,
@@ -1446,6 +1447,10 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
p->highest_bit = maxpages - 1;
error = -EINVAL;
+ if (!maxpages)
+ 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;
@@ -1470,25 +1475,27 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
if (error)
goto bad_swap;
}
-
+
if (swapfilesize && maxpages > swapfilesize) {
printk(KERN_WARNING
"Swap area shorter than signature indicates\n");
error = -EINVAL;
goto bad_swap;
}
+ if (nr_good_pages) {
+ p->swap_map[0] = SWAP_MAP_BAD;
+ p->max = maxpages;
+ p->pages = nr_good_pages;
+ error = setup_swap_extents(p);
+ if (error)
+ goto bad_swap;
+ nr_good_pages = p->pages;
+ }
if (!nr_good_pages) {
printk(KERN_WARNING "Empty swap-file\n");
error = -EINVAL;
goto bad_swap;
}
- p->swap_map[0] = SWAP_MAP_BAD;
- p->max = maxpages;
- p->pages = nr_good_pages;
-
- error = setup_swap_extents(p);
- if (error)
- goto bad_swap;
down(&swapon_sem);
swap_list_lock();