src/patches/suse-2.6.27.39/patches.fixes/scsi-fixup-recovered-error

   1 From: James Bottomley <James.Bottomley@HansenPartnership.com>
   2 Date: Mon Mar 30 16:55:51 2009 +0000
   3 X-Git: a9bddd74630b2a1f2dedc537417c372b2d9edc76
   4 Subject: scsi: fix recovered error handling
   5 References: bnc#487412
   6
   7 We have a problem with recovered error handling in that any command
   8 which goes down as BLOCK_PC but which returns a sense code of RECOVERED
   9 ERROR gets completed with -EIO.  For actual SG_IO commands, this doesn't
  10 matter at all, since the error return code gets dropped in favour of
  11 req->errors which contain the SCSI completion code.
  12
  13 However, if this command is part of the block system, then it will pay
  14 attention to the returned error code.  In particularly if a SYNCHRONIZE
  15 CACHE from a barrier command completes with RECOVERED ERROR, the
  16 resulting -EIO on the barrier causes block to error the request and
  17 return it to the filesystem.  Fix this by converting the -EIO for
  18 recovered error to zero, plus remove the printing of this from sd and
  19 sr so the message isn't double printed.
  20
  21 Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
  22 Signed-off-by: Hannes Reinecke <hare@suse.de>
  23
  24 diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
  25 index 4b13e36..d1cb64a 100644
  26 --- a/drivers/scsi/scsi_lib.c
  27 +++ b/drivers/scsi/scsi_lib.c
  28 @@ -791,7 +791,22 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
  29                                       "%d bytes done.\n",
  30                                       req->nr_sectors, good_bytes));
  31
  32 -       /* A number of bytes were successfully read.  If there
  33 +       /*
  34 +        * Recovered errors need reporting, but they're always treated
  35 +        * as success, so fiddle the result code here.  For BLOCK_PC
  36 +        * we already took a copy of the original into rq->errors which
  37 +        * is what gets returned to the user
  38 +        */
  39 +       if (sense_valid && sshdr.sense_key == RECOVERED_ERROR) {
  40 +               if (!(req->cmd_flags & REQ_QUIET))
  41 +                       scsi_print_sense("", cmd);
  42 +               result = 0;
  43 +               /* BLOCK_PC may have set error */
  44 +               error = 0;
  45 +       }
  46 +
  47 +       /*
  48 +        * A number of bytes were successfully read.  If there
  49          * are leftovers and there is some kind of error
  50          * (result != 0), retry the rest.
  51          */
  52 diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
  53 index aeab5d9..3fcb64b 100644
  54 --- a/drivers/scsi/sd.c
  55 +++ b/drivers/scsi/sd.c
  56 @@ -1051,12 +1051,6 @@ static int sd_done(struct scsi_cmnd *SCpnt)
  57                 good_bytes = sd_completed_bytes(SCpnt);
  58                 break;
  59         case RECOVERED_ERROR:
  60 -               /* Inform the user, but make sure that it's not treated
  61 -                * as a hard error.
  62 -                */
  63 -               scsi_print_sense("sd", SCpnt);
  64 -               SCpnt->result = 0;
  65 -               memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
  66                 good_bytes = scsi_bufflen(SCpnt);
  67                 break;
  68         case NO_SENSE:
  69 diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
  70 index e7fa3ca..0e1a0f2 100644
  71 --- a/drivers/scsi/sr.c
  72 +++ b/drivers/scsi/sr.c
  73 @@ -309,15 +309,6 @@ static int sr_done(struct scsi_cmnd *SCpnt)
  74                         break;
  75
  76                 case RECOVERED_ERROR:
  77 -
  78 -                       /*
  79 -                        * An error occured, but it recovered.  Inform the
  80 -                        * user, but make sure that it's not treated as a
  81 -                        * hard error.
  82 -                        */
  83 -                       scsi_print_sense("sr", SCpnt);
  84 -                       SCpnt->result = 0;
  85 -                       SCpnt->sense_buffer[0] = 0x0;
  86                         good_bytes = this_count;
  87                         break;
  88