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Diffstat (limited to 'Documentation/target/tcmu-design.txt')
| -rw-r--r-- | Documentation/target/tcmu-design.txt | 18 |
1 files changed, 7 insertions, 11 deletions
diff --git a/Documentation/target/tcmu-design.txt b/Documentation/target/tcmu-design.txt index 43e94ea6d2ca..c80bf1ed8981 100644 --- a/Documentation/target/tcmu-design.txt +++ b/Documentation/target/tcmu-design.txt @@ -15,7 +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 +3) Command filtering 4) A final note @@ -360,17 +360,13 @@ int handle_device_events(int fd, void *map) } -Command filtering and pass_level --------------------------------- +Command filtering +----------------- -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: +Initial TCMU support is for a filtered commandset. Only IO-related +commands are presented to userspace, and the rest are handled by LIO's +in-kernel command emulation. The commands presented are all versions +of: READ WRITE |