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| author | Omar Sandoval <osandov@fb.com> | 2018-10-26 15:10:55 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-10-26 16:38:15 -0700 |
| commit | aa8aa8a331d27fcef3e60dabb918eb8c5c9a2ad9 (patch) | |
| tree | 5f200509a0bcf548126fc9abe385637924555853 /mm/swapfile.c | |
| parent | bc4ae27d817a4e92071ef67cb6368120cfabe7ec (diff) | |
| download | lwn-aa8aa8a331d27fcef3e60dabb918eb8c5c9a2ad9.tar.gz lwn-aa8aa8a331d27fcef3e60dabb918eb8c5c9a2ad9.zip | |
mm: export add_swap_extent()
Btrfs currently does not support swap files because swap's use of bmap
does not work with copy-on-write and multiple devices. See 35054394c4b3
("Btrfs: stop providing a bmap operation to avoid swapfile corruptions").
However, the swap code has a mechanism for the filesystem to manually add
swap extents using add_swap_extent() from the ->swap_activate() aop.
iomap has done this since 67482129cdab ("iomap: add a swapfile activation
function"). Btrfs will do the same in a later patch, so export
add_swap_extent().
Link: http://lkml.kernel.org/r/bb1208575e02829aae51b538709476964f97b1ea.1536704650.git.osandov@fb.com
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Sterba <dsterba@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/swapfile.c')
| -rw-r--r-- | mm/swapfile.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index f0c7e4c11bab..644f746e167a 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2354,6 +2354,7 @@ add_swap_extent(struct swap_info_struct *sis, unsigned long start_page, list_add_tail(&new_se->list, &sis->first_swap_extent.list); return 1; } +EXPORT_SYMBOL_GPL(add_swap_extent); /* * A `swap extent' is a simple thing which maps a contiguous range of pages |