diff options
| author | Weijie Yang <weijie.yang@samsung.com> | 2014-02-06 12:04:23 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-02-06 13:48:51 -0800 |
| commit | f893ab41e4dae2fe8991faf5d86d029068d1ef3a (patch) | |
| tree | 6cde60539b7c64f11381a58d8c07112f0e7d5d5f /mm/page-writeback.c | |
| parent | 579f82901f6f41256642936d7e632f3979ad76d4 (diff) | |
| download | lwn-f893ab41e4dae2fe8991faf5d86d029068d1ef3a.tar.gz lwn-f893ab41e4dae2fe8991faf5d86d029068d1ef3a.zip | |
mm/swap: fix race on swap_info reuse between swapoff and swapon
swapoff clear swap_info's SWP_USED flag prematurely and free its
resources after that. A concurrent swapon will reuse this swap_info
while its previous resources are not cleared completely.
These late freed resources are:
- p->percpu_cluster
- swap_cgroup_ctrl[type]
- block_device setting
- inode->i_flags &= ~S_SWAPFILE
This patch clears the SWP_USED flag after all its resources are freed,
so that swapon can reuse this swap_info by alloc_swap_info() safely.
[akpm@linux-foundation.org: tidy up code comment]
Signed-off-by: Weijie Yang <weijie.yang@samsung.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page-writeback.c')
0 files changed, 0 insertions, 0 deletions