mm: split SWP_FILE into SWP_ACTIVATED and SWP_FS
The SWP_FILE flag serves two purposes: to make swap_{read,write}page() go
through the filesystem, and to make swapoff() call ->swap_deactivate().
For Btrfs, we want the latter but not the former, so split this flag into
two. This makes us always call ->swap_deactivate() if ->swap_activate()
succeeded, not just if it didn't add any swap extents itself.
This also resolves the issue of the very misleading name of SWP_FILE,
which is only used for swap files over NFS.
Link: http://lkml.kernel.org/r/6d63d8668c4287a4f6d203d65696e96f80abdfc7.1536704650.git.osandov@fb.com
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/swap.h b/include/linux/swap.h
index b93740d..38195f5 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -167,13 +167,14 @@ enum {
SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */
SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */
SWP_BLKDEV = (1 << 6), /* its a block device */
- SWP_FILE = (1 << 7), /* set after swap_activate success */
- SWP_AREA_DISCARD = (1 << 8), /* single-time swap area discards */
- SWP_PAGE_DISCARD = (1 << 9), /* freed swap page-cluster discards */
- SWP_STABLE_WRITES = (1 << 10), /* no overwrite PG_writeback pages */
- SWP_SYNCHRONOUS_IO = (1 << 11), /* synchronous IO is efficient */
+ SWP_ACTIVATED = (1 << 7), /* set after swap_activate success */
+ SWP_FS = (1 << 8), /* swap file goes through fs */
+ SWP_AREA_DISCARD = (1 << 9), /* single-time swap area discards */
+ SWP_PAGE_DISCARD = (1 << 10), /* freed swap page-cluster discards */
+ SWP_STABLE_WRITES = (1 << 11), /* no overwrite PG_writeback pages */
+ SWP_SYNCHRONOUS_IO = (1 << 12), /* synchronous IO is efficient */
/* add others here before... */
- SWP_SCANNING = (1 << 12), /* refcount in scan_swap_map */
+ SWP_SCANNING = (1 << 13), /* refcount in scan_swap_map */
};
#define SWAP_CLUSTER_MAX 32UL