Commit 8f78fc5e authored by Kai Makisara's avatar Kai Makisara Committed by James Bottomley
Browse files

[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: default avatarKai Makisara <Kai.Makisara@kolumbus.fi>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent 02ae2c0e

drivers/scsi/st.c

+10 −1
Original line number Diff line number Diff line
@@ -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;) {

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