Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit bd441dea authored by Mike Christie's avatar Mike Christie Committed by James Bottomley
Browse files

[SCSI] fix write buffer length in scsi_req_map_sg() 



sg's may have setup a the buffer with a different length than
the transfer length so we should be using the bufflen passed
in as the request's data len.

Signed-off-by: default avatarMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent 35814740

drivers/scsi/scsi_lib.c

+10 −4
Original line number Diff line number Diff line
@@ -301,7 +301,7 @@ static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl, 
{

	struct request_queue *q = rq->q;

	int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT;

	unsigned int data_len = 0, len, bytes, off;

	unsigned int data_len = bufflen, len, bytes, off;

	struct page *page;

	struct bio *bio = NULL;

	int i, err, nr_vecs = 0;
@@ -310,10 +310,15 @@ static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl, 
		page = sgl[i].page;

		off = sgl[i].offset;

		len = sgl[i].length;

		data_len += len;



		while (len > 0) {

		while (len > 0 && data_len > 0) {

			/*

			 * sg sends a scatterlist that is larger than

			 * the data_len it wants transferred for certain

			 * IO sizes

			 */

			bytes = min_t(unsigned int, len, PAGE_SIZE - off);

			bytes = min(bytes, data_len);



			if (!bio) {

				nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
@@ -345,12 +350,13 @@ static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl, 


			page++;

			len -= bytes;

			data_len -=bytes;

			off = 0;

		}

	}



	rq->buffer = rq->data = NULL;

	rq->data_len = data_len;

	rq->data_len = bufflen;

	return 0;



free_bios: