From 0a1f127a0594d62cb23c26732686d0e2b097b264 Mon Sep 17 00:00:00 2001 From: Peter Horton Date: Tue, 1 Dec 2009 13:17:46 -0800 Subject: aoe: prevent cache aliases 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 Cc: "Ed L. Cashin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/aoe/aoecmd.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c index 965ece2c7e4..13bb69d2abb 100644 --- a/drivers/block/aoe/aoecmd.c +++ b/drivers/block/aoe/aoecmd.c @@ -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); } -- cgit v1.2.3