This patch (as1142b) consolidates a lot of repetitious code in
scsi_io_completion(). It also fixes a few comments. Most
importantly, however, it clearly distinguishes among the three sorts
of retries that can be done when a command fails to complete:
Unprepare the request and resubmit it, so that a new
command will be created for it.
Requeue the request directly so that it will be retried
immediately using the same command.
Requeue the request so that it will be retried following
a short delay.
Complete the remainder of the request with an I/O error.
[jejb: Updates
1. For several error conditions, we would now print the sense twice
in slightly different ways, so unify the location of sense
printing.
2. I added more descriptions to actual failure conditions for
better debugging
3. according to spec, ABORTED_COMMAND is supposed to be retried
(except on DIF failure). Our old behaviour of erroring it looks
to be a bug.
4. I'd prefer not to default initialise the action variable because
that ensures that every leg of the error handler has an
associated action and the compiler will warn if someone later
accidentally misses one or removes one.
]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
b60af5b0ad