target: Fix SYNCHRONIZE_CACHE zero LBA + range breakage

This patch fixes a SYNCHRONIZE_CACHE CDB handling bug with IBLOCK/FILEIO
backends where transport_cmd_get_valid_sectors() was incorrectly rejecting
a zero LBA + range CDB from being processed, and returning CHECK_CONDITION.

This includes changing transport_cmd_get_valid_sectors() to return '0' on
success and '-EINVAL' on failure (this makes more sense than sectors),
and to only check transport_cmd_get_valid_sectors() when a non zero LBA +
range SYNCHRONIZE_CACHE operation has been receieved for the non passthrough
case.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index d35c2cc..d385c31 100644 (file)
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2853,12 +2853,10 @@ static int transport_cmd_get_valid_sectors(struct se_cmd *cmd)
                        " transport_dev_end_lba(): %llu\n",
                        cmd->t_task_lba, sectors,
                        transport_dev_end_lba(dev));
-               pr_err("  We should return CHECK_CONDITION"
-                      " but we don't yet\n");
-               return 0;
+               return -EINVAL;
        }
 
-       return sectors;
+       return 0;
 }
 
 static int target_check_write_same_discard(unsigned char *flags, struct se_device *dev)
@@ -3350,10 +3348,12 @@ static int transport_generic_cmd_sequencer(
                cmd->se_cmd_flags |= SCF_EMULATE_CDB_ASYNC;
                /*
                 * Check to ensure that LBA + Range does not exceed past end of
-                * device.
+                * device for IBLOCK and FILEIO ->do_sync_cache() backend calls
                 */
-               if (!transport_cmd_get_valid_sectors(cmd))
-                       goto out_invalid_cdb_field;
+               if ((cmd->t_task_lba != 0) || (sectors != 0)) {
+                       if (transport_cmd_get_valid_sectors(cmd) < 0)
+                               goto out_invalid_cdb_field;
+               }
                break;
        case UNMAP:
                size = get_unaligned_be16(&cdb[7]);