From e8e6c2ec403ecfaa226857d8204344c98fe12b7b Mon Sep 17 00:00:00 2001 From: Cesar Eduardo Barros Date: Tue, 22 Mar 2011 16:33:16 -0700 Subject: 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 Tested-by: Eric B Munson Acked-by: Eric B Munson Reviewed-by: Pekka Enberg Reviewed-by: KAMEZAWA Hiroyuki Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swapfile.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'mm/swapfile.c') diff --git a/mm/swapfile.c b/mm/swapfile.c index 971464470938..5238d8d15d78 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; -- cgit v1.2.3