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[SCSI] scsi_error: fix target reset handling
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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>
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James Bottomley authored and James Bottomley committed Oct 13, 2008
1 parent ea2151b commit c82dc88
Showing 1 changed file with 15 additions and 4 deletions.
19 changes: 15 additions & 4 deletions drivers/scsi/scsi_error.c
Original file line number Diff line number Diff line change
Expand Up @@ -1065,19 +1065,29 @@ 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)) {
tgtr_scmd = scmd;
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",
Expand All @@ -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);
}
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