[SCSI] st: retry enlarge_buffer allocation

Make enlarge_buffer() retry allocation if the previously chosen page
order was too small. Really limit the page order to 6. Return error if
the maximum order is not large enough for the request.

Signed-off-by: Kai Makisara <Kai.Makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This commit is contained in:
Kai Makisara 2008-12-18 14:49:51 +09:00 committed by James Bottomley
parent 02ae2c0e84
commit 8f78fc5eb7

View File

@ -3695,6 +3695,8 @@ static struct st_buffer *new_tape_buffer(int need_dma, int max_sg)
/* Try to allocate enough space in the tape buffer */
#define ST_MAX_ORDER 6
static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dma)
{
int segs, nbr, max_segs, b_size, order, got;
@ -3723,9 +3725,16 @@ static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dm
b_size = PAGE_SIZE << order;
} else {
for (b_size = PAGE_SIZE, order = 0;
order <= 6 && b_size < new_size; order++, b_size *= 2)
order < ST_MAX_ORDER && b_size < new_size;
order++, b_size *= 2)
; /* empty */
}
if (max_segs * (PAGE_SIZE << order) < new_size) {
if (order == ST_MAX_ORDER)
return 0;
normalize_buffer(STbuffer);
return enlarge_buffer(STbuffer, new_size, need_dma);
}
for (segs = STbuffer->frp_segs, got = STbuffer->buffer_size;
segs < max_segs && got < new_size;) {