scsi: target: fix crash with iscsi target and dvd

When the current page can't be added to bio, one new bio should be
created for adding this page again, instead of ignoring this page.

This patch fixes kernel crash with iscsi target and dvd, as reported by
Wakko.

Cc: Wakko Warner <wakko@animx.eu.org>
Cc: Bart Van Assche <Bart.VanAssche@wdc.com>
Cc: target-devel@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: Christoph Hellwig <hch@lst.de>
Fixes: 84c8590646d5b35804 ("target: avoid accessing .bi_vcnt directly")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index 0d99b242e82e3f84da25a47564f96db60be4b5f5..6cb933ecc084029f420fb2e13784a01f9c97e434 100644 (file)
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -890,6 +890,7 @@ pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
                        bytes = min(bytes, data_len);
 
                        if (!bio) {
+new_bio:
                                nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
                                nr_pages -= nr_vecs;
                                /*
@@ -931,6 +932,7 @@ pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
                                 * be allocated with pscsi_get_bio() above.
                                 */
                                bio = NULL;
+                               goto new_bio;
                        }
 
                        data_len -= bytes;