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authorLinus Torvalds <torvalds@linux-foundation.org>2016-06-26 10:08:49 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-06-26 10:08:49 -0700
commit2ac9b9735b4d1924d7484e497c930ea013a29ac1 (patch)
treebb8f3396fb6926735834eb989b68491f7ef55207
parentda2f6aba4a21f8da3331e5251a117c52764da579 (diff)
parent951d77fd5a541d68eeb7372e72cd4757e3058517 (diff)
Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley: "Two straightforward fixes. One is a concurrency issue only affecting SAS connected SATA drives, but which could hang the storage subsystem if it triggers (because the outstanding command count on error never goes back to zero) and the other is a NO_TAG fallout from the switch to hostwide tags which causes the system to crash on module insertion (we've checked carefully and only the 53c700 family of drivers is vulnerable to this issue)" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: 53c700: fix BUG on untagged commands scsi: fix race between simultaneous decrements of ->host_failed
-rw-r--r--Documentation/scsi/scsi_eh.txt8
-rw-r--r--drivers/ata/libata-eh.c2
-rw-r--r--drivers/scsi/53c700.c4
-rw-r--r--drivers/scsi/scsi_error.c4
4 files changed, 12 insertions, 6 deletions
diff --git a/Documentation/scsi/scsi_eh.txt b/Documentation/scsi/scsi_eh.txt
index 8638f61c8c9d..37eca00796ee 100644
--- a/Documentation/scsi/scsi_eh.txt
+++ b/Documentation/scsi/scsi_eh.txt
@@ -263,19 +263,23 @@ scmd->allowed.
3. scmd recovered
ACTION: scsi_eh_finish_cmd() is invoked to EH-finish scmd
- - shost->host_failed--
- clear scmd->eh_eflags
- scsi_setup_cmd_retry()
- move from local eh_work_q to local eh_done_q
LOCKING: none
+ CONCURRENCY: at most one thread per separate eh_work_q to
+ keep queue manipulation lockless
4. EH completes
ACTION: scsi_eh_flush_done_q() retries scmds or notifies upper
- layer of failure.
+ layer of failure. May be called concurrently but must have
+ a no more than one thread per separate eh_work_q to
+ manipulate the queue locklessly
- scmd is removed from eh_done_q and scmd->eh_entry is cleared
- if retry is necessary, scmd is requeued using
scsi_queue_insert()
- otherwise, scsi_finish_command() is invoked for scmd
+ - zero shost->host_failed
LOCKING: queue or finish function performs appropriate locking
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 61dc7a99e89a..c6f017458958 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -606,7 +606,7 @@ void ata_scsi_error(struct Scsi_Host *host)
ata_scsi_port_error_handler(host, ap);
/* finish or retry handled scmd's and clean up */
- WARN_ON(host->host_failed || !list_empty(&eh_work_q));
+ WARN_ON(!list_empty(&eh_work_q));
DPRINTK("EXIT\n");
}
diff --git a/drivers/scsi/53c700.c b/drivers/scsi/53c700.c
index d4c285688ce9..3ddc85e6efd6 100644
--- a/drivers/scsi/53c700.c
+++ b/drivers/scsi/53c700.c
@@ -1122,7 +1122,7 @@ process_script_interrupt(__u32 dsps, __u32 dsp, struct scsi_cmnd *SCp,
} else {
struct scsi_cmnd *SCp;
- SCp = scsi_host_find_tag(SDp->host, SCSI_NO_TAG);
+ SCp = SDp->current_cmnd;
if(unlikely(SCp == NULL)) {
sdev_printk(KERN_ERR, SDp,
"no saved request for untagged cmd\n");
@@ -1826,7 +1826,7 @@ NCR_700_queuecommand_lck(struct scsi_cmnd *SCp, void (*done)(struct scsi_cmnd *)
slot->tag, slot);
} else {
slot->tag = SCSI_NO_TAG;
- /* must populate current_cmnd for scsi_host_find_tag to work */
+ /* save current command for reselection */
SCp->device->current_cmnd = SCp;
}
/* sanity check: some of the commands generated by the mid-layer
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index a8b610eaa0ca..106a6adbd6f1 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1128,7 +1128,6 @@ static int scsi_eh_action(struct scsi_cmnd *scmd, int rtn)
*/
void scsi_eh_finish_cmd(struct scsi_cmnd *scmd, struct list_head *done_q)
{
- scmd->device->host->host_failed--;
scmd->eh_eflags = 0;
list_move_tail(&scmd->eh_entry, done_q);
}
@@ -2227,6 +2226,9 @@ int scsi_error_handler(void *data)
else
scsi_unjam_host(shost);
+ /* All scmds have been handled */
+ shost->host_failed = 0;
+
/*
* Note - if the above fails completely, the action is to take
* individual devices offline and flush the queue of any