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| author | Kent Overstreet <kmo@daterainc.com> | 2013-12-16 23:12:09 +0100 |
|---|---|---|
| committer | Kent Overstreet <kmo@daterainc.com> | 2013-12-16 23:22:58 +0100 |
| commit | 6d3d1a9c542b19dff1c7d7c8354d0869e4655287 (patch) | |
| tree | 92afafc81797f8ad6ed2548e25f9818f7f67a8d4 | |
| parent | bcache: fix for gc and writeback race (diff) | |
| download | linux-6d3d1a9c542b19dff1c7d7c8354d0869e4655287.tar.xz linux-6d3d1a9c542b19dff1c7d7c8354d0869e4655287.zip | |
bcache: bugfix for race between moving_gc and bucket_invalidate
There is a possibility for a bucket to be invalidated by the allocator
while moving_gc was copying it's contents to another bucket, if the
bucket only held cached data. To prevent this moving checks for
a stale ptr (to an invalidated bucket), before and after reads.
It it finds one, it simply ignores moving that data. This only
affects bcache if the moving_gc was turned on, note that it's
off by default.
Signed-off-by: Nicholas Swenson <nks@daterainc.com>
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
| -rw-r--r-- | drivers/md/bcache/movinggc.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/md/bcache/movinggc.c b/drivers/md/bcache/movinggc.c index 30f347d4e609..f2f0998c4a91 100644 --- a/drivers/md/bcache/movinggc.c +++ b/drivers/md/bcache/movinggc.c @@ -64,11 +64,16 @@ static void write_moving_finish(struct closure *cl) static void read_moving_endio(struct bio *bio, int error) { + struct bbio *b = container_of(bio, struct bbio, bio); struct moving_io *io = container_of(bio->bi_private, struct moving_io, cl); if (error) io->op.error = error; + else if (!KEY_DIRTY(&b->key) && + ptr_stale(io->op.c, &b->key, 0)) { + io->op.error = -EINTR; + } bch_bbio_endio(io->op.c, bio, error, "reading data to move"); } @@ -140,6 +145,11 @@ static void read_moving(struct cache_set *c) if (!w) break; + if (ptr_stale(c, &w->key, 0)) { + bch_keybuf_del(&c->moving_gc_keys, w); + continue; + } + io = kzalloc(sizeof(struct moving_io) + sizeof(struct bio_vec) * DIV_ROUND_UP(KEY_SIZE(&w->key), PAGE_SECTORS), GFP_KERNEL); |