From fa8584566cc9cdaf067dbc12132792887a521da9 Mon Sep 17 00:00:00 2001 From: Aaro Koskinen Date: Tue, 14 Apr 2009 15:47:00 -0500 Subject: [PATCH] [SCSI] sym53c8xx_2: slave_alloc/destroy safety (2.6.27.5) 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 Tested-by: Tony Battersby Signed-off-by: Mike Christie Signed-off-by: James Bottomley --- drivers/scsi/sym53c8xx_2/sym_glue.c | 66 +++++++++++++++++++++++------ drivers/scsi/sym53c8xx_2/sym_hipd.c | 40 ++++++++++++++++- drivers/scsi/sym53c8xx_2/sym_hipd.h | 2 + 3 files changed, 93 insertions(+), 15 deletions(-) diff --git a/drivers/scsi/sym53c8xx_2/sym_glue.c b/drivers/scsi/sym53c8xx_2/sym_glue.c index 583966ec8266..45374d66d26a 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 @@ -753,26 +756,37 @@ static int sym53c8xx_slave_alloc(struct scsi_device *sdev) if (tp->usrflags & SYM_SCAN_BOOT_DISABLED) { tp->usrflags &= ~SYM_SCAN_BOOT_DISABLED; - starget_printk(KERN_INFO, tp->starget, + starget_printk(KERN_INFO, sdev->sdev_target, "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; - starget_printk(KERN_INFO, tp->starget, + if (sdev->lun != 0) { + error = -ENXIO; + goto out; + } + starget_printk(KERN_INFO, sdev->sdev_target, "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 60d6a6d23088..69ad4945c936 100644 --- a/drivers/scsi/sym53c8xx_2/sym_hipd.c +++ b/drivers/scsi/sym53c8xx_2/sym_hipd.c @@ -4997,7 +4997,7 @@ struct sym_lcb *sym_alloc_lcb (struct sym_hcb *np, u_char tn, u_char ln) */ if (ln && !tp->lunmp) { tp->lunmp = kcalloc(SYM_CONF_MAX_LUN, sizeof(struct sym_lcb *), - GFP_KERNEL); + GFP_ATOMIC); if (!tp->lunmp) goto fail; } @@ -5017,6 +5017,7 @@ 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. @@ -5093,6 +5094,43 @@ fail: return; } +/* + * 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. */ diff --git a/drivers/scsi/sym53c8xx_2/sym_hipd.h b/drivers/scsi/sym53c8xx_2/sym_hipd.h index 9ebc8706b6bf..053e63c86822 100644 --- a/drivers/scsi/sym53c8xx_2/sym_hipd.h +++ b/drivers/scsi/sym53c8xx_2/sym_hipd.h @@ -401,6 +401,7 @@ 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. @@ -1065,6 +1066,7 @@ 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); -- 2.30.2