Commit 98db5195 authored by James Bottomley's avatar James Bottomley
Browse files

[SCSI] fix id computation in scsi_eh_target_reset() 



The current code in scsi_eh_target_reset() has an off by one error
that actually sends spurious extra resets.  Since there's no real need
to reset the targets in numerical order, simply chunk up the command
recovery list doing target resets and pulling matching targets out of
the list (that also makes the loop O(N) instead of O(N^2).

[mike christie found and fixed a list_splice -> list_splice_init problem]

Reported-by: default avatarHillf <Danton&lt;dhillf@gmail.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@suse.de>
parent 110def85

drivers/scsi/scsi_error.c

+25 −36
Original line number Diff line number Diff line
@@ -1124,51 +1124,40 @@ static int scsi_eh_target_reset(struct Scsi_Host *shost, 
				struct list_head *work_q,

				struct list_head *done_q)

{

	struct scsi_cmnd *scmd, *tgtr_scmd, *next;

	unsigned int id = 0;

	LIST_HEAD(tmp_list);



	list_splice_init(work_q, &tmp_list);



	while (!list_empty(&tmp_list)) {

		struct scsi_cmnd *next, *scmd;

		int rtn;

		unsigned int 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)

			/* no more commands, that's it */

			break;

		scmd = list_entry(tmp_list.next, struct scsi_cmnd, eh_entry);

		id = scmd_id(scmd);



		SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending target reset "

						  "to target %d\n",

						  current->comm, id));

		rtn = scsi_try_target_reset(tgtr_scmd);

		if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {

			list_for_each_entry_safe(scmd, next, work_q, eh_entry) {

				if (id == scmd_id(scmd))

					if (!scsi_device_online(scmd->device) ||

					    rtn == FAST_IO_FAIL ||

					    !scsi_eh_tur(tgtr_scmd))

						scsi_eh_finish_cmd(scmd,

								   done_q);

			}

		} else

		rtn = scsi_try_target_reset(scmd);

		if (rtn != SUCCESS && rtn != FAST_IO_FAIL)

			SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Target reset"

							  " failed target: "

							  "%d\n",

							  current->comm, id));

		id++;

	} while(id != 0);

		list_for_each_entry_safe(scmd, next, &tmp_list, eh_entry) {

			if (scmd_id(scmd) != id)

				continue;



			if ((rtn == SUCCESS || rtn == FAST_IO_FAIL)

			    && (!scsi_device_online(scmd->device) ||

				 rtn == FAST_IO_FAIL || !scsi_eh_tur(scmd)))

				scsi_eh_finish_cmd(scmd, done_q);

			else

				/* push back on work queue for further processing */

				list_move(&scmd->eh_entry, work_q);

		}

	}



	return list_empty(work_q);

}