Eric Lee / linux-smarc-t335x-v3.2

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Commit 0a1f127a0594d62cb23c26732686d0e2b097b264

Authored by Peter Horton
Committed by Linus Torvalds
1 parent ca0297015d
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

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>

Showing 1 changed file with 21 additions and 2 deletions Side-by-side Diff

drivers/block/aoe/aoecmd.c
Diff comments   View file @ 0a1f127
... ... @@ -735,6 +735,21 @@
735 735 part_stat_unlock();
736 736 }
737 737  
  738 +/*
  739 + * Ensure we don't create aliases in VI caches
  740 + */
  741 +static inline void
  742 +killalias(struct bio *bio)
  743 +{
  744 + struct bio_vec *bv;
  745 + int i;
  746 +
  747 + if (bio_data_dir(bio) == READ)
  748 + __bio_for_each_segment(bv, bio, i, 0) {
  749 + flush_dcache_page(bv->bv_page);
  750 + }
  751 +}
  752 +
738 753 void
739 754 aoecmd_ata_rsp(struct sk_buff *skb)
740 755 {
... ... @@ -853,8 +868,12 @@
853 868  
854 869 if (buf && --buf->nframesout == 0 && buf->resid == 0) {
855 870 diskstats(d->gd, buf->bio, jiffies - buf->stime, buf->sector);
856   - n = (buf->flags & BUFFL_FAIL) ? -EIO : 0;
857   - bio_endio(buf->bio, n);
  871 + if (buf->flags & BUFFL_FAIL)
  872 + bio_endio(buf->bio, -EIO);
  873 + else {
  874 + killalias(buf->bio);
  875 + bio_endio(buf->bio, 0);
  876 + }
858 877 mempool_free(buf, d->bufpool);
859 878 }
860 879