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authorCesar Eduardo Barros <cesarb@cesarb.net>2011-03-22 16:33:16 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-22 17:44:06 -0700
commite8e6c2ec403ecfaa226857d8204344c98fe12b7b (patch)
tree93a3cdaf385c72ba1f98add399b34ba65608efff /mm/swapfile.c
parent80b0df12b808bf8e8391afae1b43f5e529f76d89 (diff)
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sys_swapon: do not depend on "type" after allocation
Within sys_swapon, after the swap_info entry has been allocated, we always have type == p->type and swap_info[type] == p. Use this fact to reduce the dependency on the "type" local variable within the function, as a preparation to move the allocation of the swap_info entry to a separate function. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: Pekka Enberg <penberg@kernel.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujisu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/swapfile.c')
-rw-r--r--mm/swapfile.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 97146447093..5238d8d15d7 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1927,7 +1927,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
for (i = 0; i < nr_swapfiles; i++) {
struct swap_info_struct *q = swap_info[i];
- if (i == type || !q->swap_file)
+ if (q == p || !q->swap_file)
continue;
if (mapping == q->swap_file->f_mapping)
goto bad_swap;
@@ -2062,7 +2062,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
}
}
- error = swap_cgroup_swapon(type, maxpages);
+ error = swap_cgroup_swapon(p->type, maxpages);
if (error)
goto bad_swap;
@@ -2120,9 +2120,9 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
}
p->next = i;
if (prev < 0)
- swap_list.head = swap_list.next = type;
+ swap_list.head = swap_list.next = p->type;
else
- swap_info[prev]->next = type;
+ swap_info[prev]->next = p->type;
spin_unlock(&swap_lock);
mutex_unlock(&swapon_mutex);
atomic_inc(&proc_poll_event);
@@ -2136,7 +2136,7 @@ bad_swap:
blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
}
destroy_swap_extents(p);
- swap_cgroup_swapoff(type);
+ swap_cgroup_swapoff(p->type);
bad_swap_2:
spin_lock(&swap_lock);
p->swap_file = NULL;