[SCSI] scsi_error: fix target reset handling

There's a target reset bug.

This loop:

	for (id = 0; id <= shost->max_id; id++) {

Never terminates if shost->max_id is set to ~0, like aic94xx does.

It's also pretty inefficient since you mostly have compact target
numbers, but the max_id can be very high.  The best way would be to
sort the recovery list by target id and skip them if they're equal,
but even a worst case O(N^2) traversal is probably OK here, so fix it
by finding the next highest target number (assuming n+1) and
terminating when there isn't one.

Cc: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 15 insertions, 4 deletions

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index ad019ece2139..94ed262bdf0c 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1065,10 +1065,10 @@ static int scsi_eh_target_reset(struct Scsi_Host *shost,
                                 struct list_head *done_q)
 {
         struct scsi_cmnd *scmd, *tgtr_scmd, *next;
-        unsigned int id;
+        unsigned int id = 0;
         int rtn;
 
-        for (id = 0; id <= shost->max_id; id++) {
+        do {
                 tgtr_scmd = NULL;
                 list_for_each_entry(scmd, work_q, eh_entry) {
                         if (id == scmd_id(scmd)) {
@@ -1076,8 +1076,18 @@ static int scsi_eh_target_reset(struct Scsi_Host *shost,
                                 break;
                         }
                 }
+                if (!tgtr_scmd) {
+                        /* not one exactly equal; find the next highest */
+                        list_for_each_entry(scmd, work_q, eh_entry) {
+                                if (scmd_id(scmd) > id &&
+                                    (!tgtr_scmd ||
+                                     scmd_id(tgtr_scmd) > scmd_id(scmd)))
+                                                tgtr_scmd = scmd;
+                        }
+                }
                 if (!tgtr_scmd)
-                        continue;
+                        /* no more commands, that's it */
+                        break;
 
                 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending target reset "
                                                   "to target %d\n",
@@ -1096,7 +1106,8 @@ static int scsi_eh_target_reset(struct Scsi_Host *shost,
                                                           " failed target: "
                                                           "%d\n",
                                                           current->comm, id));
-        }
+                id++;
+        } while(id != 0);
 
         return list_empty(work_q);
 }