pnfs-obj: Bug when we are running out of bio

When we have a situation that the number of pages we want
to encode is bigger then the size of the bio. (Which can
currently happen only when all IO is going to a single device
.e.g group_width==1) then the IO is submitted short and we
report back only the amount of bytes we actually wrote/read
and all is fine. BUT ...

There was a bug that the current length counter was advanced
before the fail to add the extra page, and we come to a situation
that the CDB length was one-page longer then the actual bio size,
which is of course rejected by the osd-target.

While here also fix the bio size calculation, in the case
that we received more then one group of devices.

CC: Stable Tree <stable@kernel.org>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Boaz Harrosh 2011-08-03 21:54:33 -07:00 committed by Trond Myklebust
parent 88c9e42196
commit 20618b21da
1 changed files with 5 additions and 7 deletions

View File

@ -589,22 +589,19 @@ static void _calc_stripe_info(struct objio_state *ios, u64 file_offset,
}
static int _add_stripe_unit(struct objio_state *ios, unsigned *cur_pg,
unsigned pgbase, struct _objio_per_comp *per_dev, int cur_len,
unsigned pgbase, struct _objio_per_comp *per_dev, int len,
gfp_t gfp_flags)
{
unsigned pg = *cur_pg;
int cur_len = len;
struct request_queue *q =
osd_request_queue(_io_od(ios, per_dev->dev));
per_dev->length += cur_len;
if (per_dev->bio == NULL) {
unsigned stripes = ios->layout->num_comps /
ios->layout->mirrors_p1;
unsigned pages_in_stripe = stripes *
unsigned pages_in_stripe = ios->layout->group_width *
(ios->layout->stripe_unit / PAGE_SIZE);
unsigned bio_size = (ios->ol_state.nr_pages + pages_in_stripe) /
stripes;
ios->layout->group_width;
if (BIO_MAX_PAGES_KMALLOC < bio_size)
bio_size = BIO_MAX_PAGES_KMALLOC;
@ -632,6 +629,7 @@ static int _add_stripe_unit(struct objio_state *ios, unsigned *cur_pg,
}
BUG_ON(cur_len);
per_dev->length += len;
*cur_pg = pg;
return 0;
}