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| author | Hugh Dickins <hugh@veritas.com> | 2006-09-29 02:01:26 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-09-29 09:18:23 -0700 |
| commit | 3f9e7949f86dfe2bd9a1ad0604f78e7683c059de (patch) | |
| tree | af710aa375e0f641ceec1bf7d4002ef33beeb571 /mm/swapfile.c | |
| parent | 2d1d43f6a43b703587e759145f69467e7c6553a7 (diff) | |
| download | lwn-3f9e7949f86dfe2bd9a1ad0604f78e7683c059de.tar.gz lwn-3f9e7949f86dfe2bd9a1ad0604f78e7683c059de.zip | |
[PATCH] valid_swaphandles() fix
akpm draws my attention to the fact that sysctl(VM_PAGE_CLUSTER) might
conceivably change page_cluster to 0 while valid_swaphandles() is in the
middle of using it, leading to an embarrassingly long loop: take a local
snapshot of page_cluster and work with that.
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/swapfile.c')
| -rw-r--r-- | mm/swapfile.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index f1f5ec783781..a15def63f28f 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1723,13 +1723,14 @@ get_swap_info_struct(unsigned type) */ int valid_swaphandles(swp_entry_t entry, unsigned long *offset) { - int ret = 0, i = 1 << page_cluster; + int our_page_cluster = page_cluster; + int ret = 0, i = 1 << our_page_cluster; unsigned long toff; struct swap_info_struct *swapdev = swp_type(entry) + swap_info; - if (!page_cluster) /* no readahead */ + if (!our_page_cluster) /* no readahead */ return 0; - toff = (swp_offset(entry) >> page_cluster) << page_cluster; + toff = (swp_offset(entry) >> our_page_cluster) << our_page_cluster; if (!toff) /* first page is swap header */ toff++, i--; *offset = toff; |