[PATCH 2 2/4] cciss: use mutex instead of flag to indicate busyinitializing

From: Andrew Patterson
Date: Tue Jul 21 2009 - 15:55:41 EST


cciss: use mutex instead of flag to indicate busy initializing

Convert busy_initializing from simple integer flag to mutex, so we
can use it to block and thus avoid some race conditions.

Acked-by: Mike Miller <mike.miller@xxxxxx>
Signed-off-by: Andrew Patterson <andrew.patterson@xxxxxx>
---

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 970c896..085ab11 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -751,7 +751,7 @@ static int cciss_open(struct block_device *bdev, fmode_t mode)
printk(KERN_DEBUG "cciss_open %s\n", bdev->bd_disk->disk_name);
#endif /* CCISS_DEBUG */

- if (host->busy_initializing || drv->busy_configuring)
+ if (mutex_is_locked(&host->busy_initializing) || drv->busy_configuring)
return -EBUSY;
/*
* Root is allowed to open raw volume zero even if it's not configured
@@ -3915,7 +3915,8 @@ static int __devinit cciss_init_one(struct pci_dev *pdev,
if (i < 0)
return -1;

- hba[i]->busy_initializing = 1;
+ mutex_init(&hba[i]->busy_initializing);
+ mutex_lock(&hba[i]->busy_initializing);
INIT_HLIST_HEAD(&hba[i]->cmpQ);
INIT_HLIST_HEAD(&hba[i]->reqQ);

@@ -4034,7 +4035,7 @@ static int __devinit cciss_init_one(struct pci_dev *pdev,

hba[i]->cciss_max_sectors = 2048;

- hba[i]->busy_initializing = 0;
+ mutex_unlock(&hba[i]->busy_initializing);

rebuild_lun_table(hba[i], 1);
hba[i]->cciss_scan_thread = kthread_run(scan_thread, hba[i],
@@ -4062,7 +4063,7 @@ clean2:
clean1:
cciss_destroy_hba_sysfs_entry(hba[i]);
clean0:
- hba[i]->busy_initializing = 0;
+ mutex_unlock(&hba[i]->busy_initializing);
/* cleanup any queues that may have been initialized */
for (j=0; j <= hba[i]->highest_lun; j++){
drive_info_struct *drv = &(hba[i]->drv[j]);
diff --git a/drivers/block/cciss.h b/drivers/block/cciss.h
index 06a5db2..bf1699c 100644
--- a/drivers/block/cciss.h
+++ b/drivers/block/cciss.h
@@ -107,7 +107,7 @@ struct ctlr_info
int nr_allocs;
int nr_frees;
int busy_configuring;
- int busy_initializing;
+ struct mutex busy_initializing;

/* This element holds the zero based queue number of the last
* queue to be started. It is used for fairness.

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