aoe: prevent cache aliases (0a1f127a) · Commits · 戴 / test

Prevent the AoE block driver from creating cache aliases of page cache pages on machines with virtually indexed caches. Building kernels on an AT91SAM9G20 board without this patch fails with segmentation faults after a couple of passes. Signed-off-by:

Peter Horton <zero@colonel-panic.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Signed-off-by:

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

Linus Torvalds <torvalds@linux-foundation.org>

drivers/block/aoe/aoecmd.c

+21 −2

Original line number	Diff line number	Diff line
		@@ -735,6 +735,21 @@ diskstats(struct gendisk disk, struct bio bio, ulong duration, sector_t sector
		part_stat_unlock();
		}

		/*
		* Ensure we don't create aliases in VI caches
		*/
		static inline void
		killalias(struct bio *bio)
		{
		struct bio_vec *bv;
		int i;

		if (bio_data_dir(bio) == READ)
		__bio_for_each_segment(bv, bio, i, 0) {
		flush_dcache_page(bv->bv_page);
		}
		}

		void
		aoecmd_ata_rsp(struct sk_buff *skb)
		{
		@@ -853,8 +868,12 @@ aoecmd_ata_rsp(struct sk_buff *skb)

		if (buf && --buf->nframesout == 0 && buf->resid == 0) {
		diskstats(d->gd, buf->bio, jiffies - buf->stime, buf->sector);
		n = (buf->flags & BUFFL_FAIL) ? -EIO : 0;
		bio_endio(buf->bio, n);
		if (buf->flags & BUFFL_FAIL)
		bio_endio(buf->bio, -EIO);
		else {
		killalias(buf->bio);
		bio_endio(buf->bio, 0);
		}
		mempool_free(buf, d->bufpool);
		}

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