X-Git-Url: https://nv-tegra.nvidia.com/r/gitweb?p=linux-2.6.git;a=blobdiff_plain;f=Documentation%2Fscsi%2Fscsi_eh.txt;h=7acbebb17fa6c42bd07f1da11311dde70b4bc60b;hp=534a50922a7b0b4efe3a1e64f559432e7ae040ef;hb=78e0c621deca08e5f802383dbe75fd20b258ea4e;hpb=70c83e110541e894fa16aee0f57bcf4207b33e7b diff --git a/Documentation/scsi/scsi_eh.txt b/Documentation/scsi/scsi_eh.txt index 534a50922a7..7acbebb17fa 100644 --- a/Documentation/scsi/scsi_eh.txt +++ b/Documentation/scsi/scsi_eh.txt @@ -19,9 +19,9 @@ TABLE OF CONTENTS [2-1-1] Overview [2-1-2] Flow of scmds through EH [2-1-3] Flow of control - [2-2] EH through hostt->eh_strategy_handler() - [2-2-1] Pre hostt->eh_strategy_handler() SCSI midlayer conditions - [2-2-2] Post hostt->eh_strategy_handler() SCSI midlayer conditions + [2-2] EH through transportt->eh_strategy_handler() + [2-2-1] Pre transportt->eh_strategy_handler() SCSI midlayer conditions + [2-2-2] Post transportt->eh_strategy_handler() SCSI midlayer conditions [2-2-3] Things to consider @@ -75,7 +75,7 @@ with the command. - otherwise scsi_eh_scmd_add(scmd, 0) is invoked for the command. See - [1-3] for details of this funciton. + [1-3] for details of this function. [1-2-2] Completing a scmd w/ timeout @@ -83,11 +83,11 @@ with the command. The timeout handler is scsi_times_out(). When a timeout occurs, this function - 1. invokes optional hostt->eh_timedout() callback. Return value can + 1. invokes optional hostt->eh_timed_out() callback. Return value can be one of - EH_HANDLED - This indicates that eh_timedout() dealt with the timeout. The + This indicates that eh_timed_out() dealt with the timeout. The scmd is passed to __scsi_done() and thus linked into per-cpu scsi_done_q. Normal command completion described in [1-2-1] follows. @@ -105,7 +105,7 @@ function command will time out again. - EH_NOT_HANDLED - This is the same as when eh_timedout() callback doesn't exist. + This is the same as when eh_timed_out() callback doesn't exist. Step #2 is taken. 2. scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD) is invoked for the @@ -142,7 +142,7 @@ are linked on shost->eh_cmd_q. Note that this does not mean lower layers are quiescent. If a LLDD completed a scmd with error status, the LLDD and lower layers are assumed to forget about the scmd at that point. However, if a scmd -has timed out, unless hostt->eh_timedout() made lower layers forget +has timed out, unless hostt->eh_timed_out() made lower layers forget about the scmd, which currently no LLDD does, the command is still active as long as lower layers are concerned and completion could occur at any time. Of course, all such completions are ignored as the @@ -160,7 +160,7 @@ ways. - Fine-grained EH callbacks LLDD can implement fine-grained EH callbacks and let SCSI midlayer drive error handling and call appropriate callbacks. - This will be dicussed further in [2-1]. + This will be discussed further in [2-1]. - eh_strategy_handler() callback This is one big callback which should perform whole error @@ -194,7 +194,7 @@ lower layers and lower layers are ready to process or fail the scmd again. To achieve these goals, EH performs recovery actions with increasing -severity. Some actions are performed by issueing SCSI commands and +severity. Some actions are performed by issuing SCSI commands and others are performed by invoking one of the following fine-grained hostt EH callbacks. Callbacks may be omitted and omitted ones are considered to fail always. @@ -413,9 +413,9 @@ scmd->allowed. layer of failure of the scmds. -[2-2] EH through hostt->eh_strategy_handler() +[2-2] EH through transportt->eh_strategy_handler() - hostt->eh_strategy_handler() is invoked in the place of + transportt->eh_strategy_handler() is invoked in the place of scsi_unjam_host() and it is responsible for whole recovery process. On completion, the handler should have made lower layers forget about all failed scmds and either ready for new commands or offline. Also, @@ -424,7 +424,7 @@ SCSI midlayer. IOW, of the steps described in [2-1-2], all steps except for #1 must be implemented by eh_strategy_handler(). -[2-2-1] Pre hostt->eh_strategy_handler() SCSI midlayer conditions +[2-2-1] Pre transportt->eh_strategy_handler() SCSI midlayer conditions The following conditions are true on entry to the handler. @@ -437,7 +437,7 @@ except for #1 must be implemented by eh_strategy_handler(). - shost->host_failed == shost->host_busy -[2-2-2] Post hostt->eh_strategy_handler() SCSI midlayer conditions +[2-2-2] Post transportt->eh_strategy_handler() SCSI midlayer conditions The following conditions must be true on exit from the handler.