[SCSI] scsi_error: fix target reset handling (c82dc88d) · Commits · 戴 / test

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>

drivers/scsi/scsi_error.c

+15 −4

Original line number	Diff line number	Diff line
		@@ -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);
		}

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