diff options
Diffstat (limited to 'Documentation/target')
| -rw-r--r-- | Documentation/target/tcmu-design.txt | 33 |
1 files changed, 7 insertions, 26 deletions
diff --git a/Documentation/target/tcmu-design.txt b/Documentation/target/tcmu-design.txt index 43e94ea6d2ca..263b907517ac 100644 --- a/Documentation/target/tcmu-design.txt +++ b/Documentation/target/tcmu-design.txt @@ -15,8 +15,7 @@ Contents: a) Discovering and configuring TCMU uio devices b) Waiting for events on the device(s) c) Managing the command ring -3) Command filtering and pass_level -4) A final note +3) A final note TCM Userspace Design @@ -324,7 +323,7 @@ int handle_device_events(int fd, void *map) /* Process events from cmd ring until we catch up with cmd_head */ while (ent != (void *)mb + mb->cmdr_off + mb->cmd_head) { - if (tcmu_hdr_get_op(&ent->hdr) == TCMU_OP_CMD) { + if (tcmu_hdr_get_op(ent->hdr.len_op) == TCMU_OP_CMD) { uint8_t *cdb = (void *)mb + ent->req.cdb_off; bool success = true; @@ -339,8 +338,12 @@ int handle_device_events(int fd, void *map) ent->rsp.scsi_status = SCSI_CHECK_CONDITION; } } + else if (tcmu_hdr_get_op(ent->hdr.len_op) != TCMU_OP_PAD) { + /* Tell the kernel we didn't handle unknown opcodes */ + ent->hdr.uflags |= TCMU_UFLAG_UNKNOWN_OP; + } else { - /* Do nothing for PAD entries */ + /* Do nothing for PAD entries except update cmd_tail */ } /* update cmd_tail */ @@ -360,28 +363,6 @@ int handle_device_events(int fd, void *map) } -Command filtering and pass_level --------------------------------- - -TCMU supports a "pass_level" option with valid values of 0 or 1. When -the value is 0 (the default), nearly all SCSI commands received for -the device are passed through to the handler. This allows maximum -flexibility but increases the amount of code required by the handler, -to support all mandatory SCSI commands. If pass_level is set to 1, -then only IO-related commands are presented, and the rest are handled -by LIO's in-kernel command emulation. The commands presented at level -1 include all versions of: - -READ -WRITE -WRITE_VERIFY -XDWRITEREAD -WRITE_SAME -COMPARE_AND_WRITE -SYNCHRONIZE_CACHE -UNMAP - - A final note ------------ |