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authorPeter Horton <phorton@bitbox.co.uk>2009-12-02 00:17:46 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2009-12-02 03:32:20 +0300
commit0a1f127a0594d62cb23c26732686d0e2b097b264 (patch)
tree117efe6cf0cd6c090d5832dc9dfb117c77a3fa8b /drivers/block/aoe
parentca0297015d4f117005718e01aa368875abcccbc5 (diff)
downloadlinux-0a1f127a0594d62cb23c26732686d0e2b097b264.tar.xz
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 <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>
Diffstat (limited to 'drivers/block/aoe')
-rw-r--r--drivers/block/aoe/aoecmd.c23
1 files changed, 21 insertions, 2 deletions
diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index 965ece2c7e4d..13bb69d2abb3 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);
}