[PATCH 4/7] Return proper error code on device create failure

From: Nitin Gupta
Date: Thu Jan 28 2010 - 10:46:32 EST


Currently, we return 0 if create_device() fails and 1 otherwise.
Now, proper error code is returned from create_device() and the
same is propagated as module error code from ramzswap_init().

Also added some cleanups for ramzswap_init(), improving function
structure.

Signed-off-by: Nitin Gupta <ngupta@xxxxxxxxxx>
---
drivers/staging/ramzswap/ramzswap_drv.c | 44 +++++++++++++++++++-----------
1 files changed, 28 insertions(+), 16 deletions(-)

diff --git a/drivers/staging/ramzswap/ramzswap_drv.c b/drivers/staging/ramzswap/ramzswap_drv.c
index 2021ad6..3035add 100644
--- a/drivers/staging/ramzswap/ramzswap_drv.c
+++ b/drivers/staging/ramzswap/ramzswap_drv.c
@@ -1300,6 +1300,8 @@ static struct block_device_operations ramzswap_devops = {

static int create_device(struct ramzswap *rzs, int device_id)
{
+ int ret = 0;
+
mutex_init(&rzs->lock);
spin_lock_init(&rzs->stat64_lock);
INIT_LIST_HEAD(&rzs->backing_swap_extent_list);
@@ -1308,7 +1310,8 @@ static int create_device(struct ramzswap *rzs, int device_id)
if (!rzs->queue) {
pr_err("Error allocating disk queue for device %d\n",
device_id);
- return 0;
+ ret = -ENOMEM;
+ goto out;
}

blk_queue_make_request(rzs->queue, ramzswap_make_request);
@@ -1320,7 +1323,8 @@ static int create_device(struct ramzswap *rzs, int device_id)
blk_cleanup_queue(rzs->queue);
pr_warning("Error allocating disk structure for device %d\n",
device_id);
- return 0;
+ ret = -ENOMEM;
+ goto out;
}

rzs->disk->major = ramzswap_major;
@@ -1342,7 +1346,9 @@ static int create_device(struct ramzswap *rzs, int device_id)
add_disk(rzs->disk);

rzs->init_done = 0;
- return 1;
+
+out:
+ return ret;
}

static void destroy_device(struct ramzswap *rzs)
@@ -1358,18 +1364,20 @@ static void destroy_device(struct ramzswap *rzs)

static int __init ramzswap_init(void)
{
- int i, ret;
+ int ret, dev_id;

if (num_devices > max_num_devices) {
pr_warning("Invalid value for num_devices: %u\n",
num_devices);
- return -EINVAL;
+ ret = -EINVAL;
+ goto out;
}

ramzswap_major = register_blkdev(0, "ramzswap");
if (ramzswap_major <= 0) {
pr_warning("Unable to get major number\n");
- return -EBUSY;
+ ret = -EBUSY;
+ goto out;
}

if (!num_devices) {
@@ -1380,21 +1388,25 @@ static int __init ramzswap_init(void)
/* Allocate the device array and initialize each one */
pr_info("Creating %u devices ...\n", num_devices);
devices = kzalloc(num_devices * sizeof(struct ramzswap), GFP_KERNEL);
- if (!devices)
- goto out;
+ if (!devices) {
+ ret = -ENOMEM;
+ goto unregister;
+ }

- for (i = 0; i < num_devices; i++)
- if (!create_device(&devices[i], i)) {
- ret = i;
+ for (dev_id = 0; dev_id < num_devices; dev_id++) {
+ ret = create_device(&devices[dev_id], dev_id);
+ if (ret)
goto free_devices;
- }
+ }
+
return 0;
+
free_devices:
- for (i = 0; i < ret; i++)
- destroy_device(&devices[i]);
-out:
- ret = -ENOMEM;
+ while (dev_id)
+ destroy_device(&devices[--dev_id]);
+unregister:
unregister_blkdev(ramzswap_major, "ramzswap");
+out:
return ret;
}

--
1.6.2.5

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