pnfsblock: limit bio page count
One bio can have at most BIO_MAX_PAGES pages. We should limit it bec otherwise
bio_alloc will fail when there are many pages in one read/write_pagelist.
Cc: <stable@vger.kernel.org> #3.1+
Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index 6d39e9a..baf0bf2 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -146,14 +146,19 @@
{
struct bio *bio;
+ npg = min(npg, BIO_MAX_PAGES);
bio = bio_alloc(GFP_NOIO, npg);
- if (!bio)
- return NULL;
+ if (!bio && (current->flags & PF_MEMALLOC)) {
+ while (!bio && (npg /= 2))
+ bio = bio_alloc(GFP_NOIO, npg);
+ }
- bio->bi_sector = isect - be->be_f_offset + be->be_v_offset;
- bio->bi_bdev = be->be_mdev;
- bio->bi_end_io = end_io;
- bio->bi_private = par;
+ if (bio) {
+ bio->bi_sector = isect - be->be_f_offset + be->be_v_offset;
+ bio->bi_bdev = be->be_mdev;
+ bio->bi_end_io = end_io;
+ bio->bi_private = par;
+ }
return bio;
}