dm io: delay dec_count (c897feb3) · Commits · 戴 / test

Delay decrementing the 'struct io' reference count until after the bio has been freed so that a bio destructor function may reference it. Required by a later patch. Signed-off-by:

Heinz Mauelshagen <hjm@redhat.com> Signed-off-by:

Alasdair G Kergon <agk@redhat.com> Cc: Milan Broz <mbroz@redhat.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

drivers/md/dm-io.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -126,7 +126,8 @@ static void dec_count(struct io *io, unsigned int region, int error)

		static int endio(struct bio *bio, unsigned int done, int error)
		{
		struct io io = (struct io ) bio->bi_private;
		struct io *io;
		unsigned region;

		/* keep going until we've finished */
		if (bio->bi_size)
		@@ -135,10 +136,17 @@ static int endio(struct bio *bio, unsigned int done, int error)
		if (error && bio_data_dir(bio) == READ)
		zero_fill_bio(bio);

		dec_count(io, bio_get_region(bio), error);
		/*
		* The bio destructor in bio_put() may use the io object.
		*/
		io = bio->bi_private;
		region = bio_get_region(bio);

		bio->bi_max_vecs++;
		bio_put(bio);

		dec_count(io, region, error);

		return 0;
		}

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