(Updated based on Mike Christie's comments.)
Make the sym53c8xx_2 driver slave_alloc/destroy less unsafe. References
to the destroyed LCB are cleared from the target structure (instead of
leaving a dangling pointer), and when the last LCB for the target is
destroyed the reference to the upper layer target data is cleared. The
host lock is used to prevent a race with the interrupt handler. Also
user commands are prevented for targets with all LCBs destroyed.
Signed-off-by: Aaro Koskinen <Aaro.Koskinen@xxxxxxxxx>
---
drivers/scsi/sym53c8xx_2/sym_glue.c | 62 ++++++++++++++++++++++++++++-------
drivers/scsi/sym53c8xx_2/sym_hipd.c | 38 +++++++++++++++++++++
drivers/scsi/sym53c8xx_2/sym_hipd.h | 2 +
3 files changed, 90 insertions(+), 12 deletions(-)
diff --git a/drivers/scsi/sym53c8xx_2/sym_glue.c b/drivers/scsi/sym53c8xx_2/sym_glue.c
index d39107b..c518585 100644
--- a/drivers/scsi/sym53c8xx_2/sym_glue.c
+++ b/drivers/scsi/sym53c8xx_2/sym_glue.c
@@ -737,11 +737,14 @@ static int sym53c8xx_slave_alloc(struct scsi_device *sdev)
struct sym_hcb *np = sym_get_hcb(sdev->host);
struct sym_tcb *tp = &np->target[sdev->id];
struct sym_lcb *lp;
+ unsigned long flags;
+ int error;
if (sdev->id >= SYM_CONF_MAX_TARGET || sdev->lun >= SYM_CONF_MAX_LUN)
return -ENXIO;
- tp->starget = sdev->sdev_target;
+ spin_lock_irqsave(np->s.host->host_lock, flags);
+
/*
* Fail the device init if the device is flagged NOSCAN at BOOT in
* the NVRAM. This may speed up boot and maintain coherency with
@@ -755,24 +758,35 @@ static int sym53c8xx_slave_alloc(struct scsi_device *sdev)
tp->usrflags &= ~SYM_SCAN_BOOT_DISABLED;
starget_printk(KERN_INFO, tp->starget,
"Scan at boot disabled in NVRAM\n");
- return -ENXIO;
+ error = -ENXIO;
+ goto out;
}
if (tp->usrflags & SYM_SCAN_LUNS_DISABLED) {
- if (sdev->lun != 0)
- return -ENXIO;
+ if (sdev->lun != 0) {
+ error = -ENXIO;
+ goto out;
+ }
starget_printk(KERN_INFO, tp->starget,
"Multiple LUNs disabled in NVRAM\n");
}
lp = sym_alloc_lcb(np, sdev->id, sdev->lun);
- if (!lp)
- return -ENOMEM;
+ if (!lp) {
+ error = -ENOMEM;
+ goto out;
+ }
+ if (tp->nlcb == 1)
+ tp->starget = sdev->sdev_target;
spi_min_period(tp->starget) = tp->usr_period;
spi_max_width(tp->starget) = tp->usr_width;
- return 0;
+ error = 0;
+out:
+ spin_unlock_irqrestore(np->s.host->host_lock, flags);
+
+ return error;
}
/*
@@ -819,12 +833,34 @@ static int sym53c8xx_slave_configure(struct scsi_device *sdev)
static void sym53c8xx_slave_destroy(struct scsi_device *sdev)
{
struct sym_hcb *np = sym_get_hcb(sdev->host);
- struct sym_lcb *lp = sym_lp(&np->target[sdev->id], sdev->lun);
+ struct sym_tcb *tp = &np->target[sdev->id];
+ struct sym_lcb *lp = sym_lp(tp, sdev->lun);
+ unsigned long flags;
+
+ spin_lock_irqsave(np->s.host->host_lock, flags);
+
+ if (lp->busy_itlq || lp->busy_itl) {
+ /*
+ * This really shouldn't happen, but we can't return an error
+ * so let's try to stop all on-going I/O.
+ */
+ starget_printk(KERN_WARNING, tp->starget,
+ "Removing busy LCB (%d)\n", sdev->lun);
+ sym_reset_scsi_bus(np, 1);
+ }
- if (lp->itlq_tbl)
- sym_mfree_dma(lp->itlq_tbl, SYM_CONF_MAX_TASK * 4, "ITLQ_TBL");
- kfree(lp->cb_tags);
- sym_mfree_dma(lp, sizeof(*lp), "LCB");
+ if (sym_free_lcb(np, sdev->id, sdev->lun) == 0) {
+ /*
+ * It was the last unit for this target.
+ */
+ tp->head.sval = 0;
+ tp->head.wval = np->rv_scntl3;
+ tp->head.uval = 0;
+ tp->tgoal.check_nego = 1;
+ tp->starget = NULL;
+ }
+
+ spin_unlock_irqrestore(np->s.host->host_lock, flags);
}
/*
@@ -890,6 +926,8 @@ static void sym_exec_user_command (struct sym_hcb *np, struct sym_usrcmd *uc)
if (!((uc->target >> t) & 1))
continue;
tp = &np->target[t];
+ if (!tp->nlcb)
+ continue;
switch (uc->cmd) {
diff --git a/drivers/scsi/sym53c8xx_2/sym_hipd.c b/drivers/scsi/sym53c8xx_2/sym_hipd.c
index 98df165..bbe0b5c 100644
--- a/drivers/scsi/sym53c8xx_2/sym_hipd.c
+++ b/drivers/scsi/sym53c8xx_2/sym_hipd.c
@@ -4973,6 +4973,7 @@ struct sym_lcb *sym_alloc_lcb (struct sym_hcb *np, u_char tn, u_char ln)
tp->lun0p = lp;
tp->head.lun0_sa = cpu_to_scr(vtobus(lp));
}
+ tp->nlcb++;
/*
* Let the itl task point to error handling.
@@ -5050,6 +5051,43 @@ fail:
}
/*
+ * Lun control block deallocation. Returns the number of valid remaing LCBs
+ * for the target.
+ */
+int sym_free_lcb(struct sym_hcb *np, u_char tn, u_char ln)
+{
+ struct sym_tcb *tp = &np->target[tn];
+ struct sym_lcb *lp = sym_lp(tp, ln);
+
+ tp->nlcb--;
+
+ if (ln) {
+ if (!tp->nlcb) {
+ kfree(tp->lunmp);
+ sym_mfree_dma(tp->luntbl, 256, "LUNTBL");
+ tp->lunmp = NULL;
+ tp->luntbl = NULL;
+ tp->head.luntbl_sa = cpu_to_scr(vtobus(np->badluntbl));
+ } else {
+ tp->luntbl[ln] = cpu_to_scr(vtobus(&np->badlun_sa));
+ tp->lunmp[ln] = NULL;
+ }
+ } else {
+ tp->lun0p = NULL;
+ tp->head.lun0_sa = cpu_to_scr(vtobus(&np->badlun_sa));
+ }
+
+ if (lp->itlq_tbl) {
+ sym_mfree_dma(lp->itlq_tbl, SYM_CONF_MAX_TASK*4, "ITLQ_TBL");
+ kfree(lp->cb_tags);
+ }
+
+ sym_mfree_dma(lp, sizeof(*lp), "LCB");
+
+ return tp->nlcb;
+}
+
+/*
* Queue a SCSI IO to the controller.
*/
int sym_queue_scsiio(struct sym_hcb *np, struct scsi_cmnd *cmd, struct sym_ccb *cp)
diff --git a/drivers/scsi/sym53c8xx_2/sym_hipd.h b/drivers/scsi/sym53c8xx_2/sym_hipd.h
index ad07880..2ec25e1 100644
--- a/drivers/scsi/sym53c8xx_2/sym_hipd.h
+++ b/drivers/scsi/sym53c8xx_2/sym_hipd.h
@@ -400,6 +400,7 @@ struct sym_tcb {
* An array of bus addresses is used on reselection.
*/
u32 *luntbl; /* LCBs bus address table */
+ int nlcb; /* Number of valid LCBs (including LUN #0) */
/*
* LUN table used by the C code.
@@ -1061,6 +1062,7 @@ int sym_clear_tasks(struct sym_hcb *np, int cam_status, int target, int lun, int
struct sym_ccb *sym_get_ccb(struct sym_hcb *np, struct scsi_cmnd *cmd, u_char tag_order);
void sym_free_ccb(struct sym_hcb *np, struct sym_ccb *cp);
struct sym_lcb *sym_alloc_lcb(struct sym_hcb *np, u_char tn, u_char ln);
+int sym_free_lcb(struct sym_hcb *np, u_char tn, u_char ln);
int sym_queue_scsiio(struct sym_hcb *np, struct scsi_cmnd *csio, struct sym_ccb *cp);
int sym_abort_scsiio(struct sym_hcb *np, struct scsi_cmnd *ccb, int timed_out);
int sym_reset_scsi_target(struct sym_hcb *np, int target);
--
1.5.4.3
--
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