diff options
| author | Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> | 2009-09-21 17:02:52 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-22 07:17:35 -0700 |
| commit | 2ca4532a49be92d7b2766c3244b30fa8bfb0114d (patch) | |
| tree | 1dc838cebacb10317dff78ceccd50b97e24c4f7f /mm/shmem.c | |
| parent | 31a5639623a487d6db996c8138c9e53fef2e2d91 (diff) | |
mm: add_to_swap_cache() does not return -EEXIST
After commit 355cfa73 ("mm: modify swap_map and add SWAP_HAS_CACHE flag"),
only the context which have set SWAP_HAS_CACHE flag by swapcache_prepare()
or get_swap_page() would call add_to_swap_cache(). So add_to_swap_cache()
doesn't return -EEXIST any more.
Even though it doesn't return -EEXIST, it's not good behavior conceptually
to call swapcache_prepare() in the -EEXIST case, because it means clearing
SWAP_HAS_CACHE flag while the entry is on swap cache.
This patch removes redundant codes and comments from callers of it, and
adds VM_BUG_ON() in error path of add_to_swap_cache() and some comments.
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/shmem.c')
| -rw-r--r-- | mm/shmem.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index bd20f8bb02aa..376d8f0a8f6b 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1097,6 +1097,10 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) shmem_swp_unmap(entry); unlock: spin_unlock(&info->lock); + /* + * add_to_swap_cache() doesn't return -EEXIST, so we can safely + * clear SWAP_HAS_CACHE flag. + */ swapcache_free(swap, NULL); redirty: set_page_dirty(page); |