hpsa: don't return abort request until target is complete
authorWebb Scales <webbnh@hp.com>
Thu, 23 Apr 2015 14:34:16 +0000 (09:34 -0500)
committerJames Bottomley <JBottomley@Odin.com>
Sun, 31 May 2015 18:37:48 +0000 (11:37 -0700)
commita58e7e53b410c8ed05f0b1b0f37411c76b8e253f
treead417864686234e35fc58c863cc2d1b423756494
parent8a0ff92cc342e6be0f4db5183b27446796c15d91
hpsa: don't return abort request until target is complete

Don't return from the abort request until the target command is complete.
Mark outstanding commands which have a pending abort, and do not send them
to the host if we can avoid it.

If the current command has been aborted, do not call the SCSI command
completion routine from the I/O path: when the abort returns successfully,
the SCSI mid-layer will handle the completion implicitly.

The following race was possible in theory.

1. LLD is requested to abort a scsi command
2. scsi command completes
3. The struct CommandList associated with 2 is made available.
4. new io request to LLD to another LUN re-uses struct CommandList
5. abort handler follows scsi_cmnd->host_scribble and
   finds struct CommandList and tries to aborts it.

Now we have aborted the wrong command.

Fix by resetting the scsi_cmd field of struct CommandList
upon completion and making the abort handler check that
the scsi_cmd pointer in the CommadList struct matches the
scsi_cmnd that it has been asked to abort.

Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Hannes Reinecke <hare@Suse.de>
Signed-off-by: Webb Scales <webbnh@hp.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
drivers/scsi/hpsa.c
drivers/scsi/hpsa.h
drivers/scsi/hpsa_cmd.h