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raw: don't keep unopened block device around

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Turn binding into a normal dev_t as the struct block device doesn't
buy us anything and use blkdev_open_by_dev to actually open it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2020-09-21 09:19:51 +02:00 committed by Jens Axboe
parent 0fc66c9d63
commit 5a56ad7882
1 changed files with 19 additions and 32 deletions
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51
drivers/char/raw.c
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@ -28,7 +28,8 @@
#include <linux/uaccess.h>
struct raw_device_data {
struct block_device *binding;
dev_t binding;
struct block_device *bdev;
int inuse;
};
@ -73,14 +74,15 @@ static int raw_open(struct inode *inode, struct file *filp)
/*
* All we need to do on open is check that the device is bound.
*/
bdev = raw_devices[minor].binding;
err = -ENODEV;
if (!bdev)
if (!raw_devices[minor].binding)
goto out;
bdgrab(bdev);
err = blkdev_get(bdev, filp->f_mode | FMODE_EXCL, raw_open);
if (err)
bdev = blkdev_get_by_dev(raw_devices[minor].binding,
filp->f_mode | FMODE_EXCL, raw_open);
if (IS_ERR(bdev)) {
err = PTR_ERR(bdev);
goto out;
}
err = set_blocksize(bdev, bdev_logical_block_size(bdev));
if (err)
goto out1;
@ -90,6 +92,7 @@ static int raw_open(struct inode *inode, struct file *filp)
file_inode(filp)->i_mapping =
bdev->bd_inode->i_mapping;
filp->private_data = bdev;
raw_devices[minor].bdev = bdev;
mutex_unlock(&raw_mutex);
return 0;
@ -110,7 +113,7 @@ static int raw_release(struct inode *inode, struct file *filp)
struct block_device *bdev;
mutex_lock(&raw_mutex);
bdev = raw_devices[minor].binding;
bdev = raw_devices[minor].bdev;
if (--raw_devices[minor].inuse == 0)
/* Here inode->i_mapping == bdev->bd_inode->i_mapping */
inode->i_mapping = &inode->i_data;
@ -133,6 +136,7 @@ raw_ioctl(struct file *filp, unsigned int command, unsigned long arg)
static int bind_set(int number, u64 major, u64 minor)
{
dev_t dev = MKDEV(major, minor);
dev_t raw = MKDEV(RAW_MAJOR, number);
struct raw_device_data *rawdev;
int err = 0;
@ -166,25 +170,17 @@ static int bind_set(int number, u64 major, u64 minor)
mutex_unlock(&raw_mutex);
return -EBUSY;
}
if (rawdev->binding) {
bdput(rawdev->binding);
if (rawdev->binding)
module_put(THIS_MODULE);
}
rawdev->binding = dev;
if (!dev) {
/* unbind */
rawdev->binding = NULL;
device_destroy(raw_class, MKDEV(RAW_MAJOR, number));
device_destroy(raw_class, raw);
} else {
rawdev->binding = bdget(dev);
if (rawdev->binding == NULL) {
err = -ENOMEM;
} else {
dev_t raw = MKDEV(RAW_MAJOR, number);
__module_get(THIS_MODULE);
device_destroy(raw_class, raw);
device_create(raw_class, NULL, raw, NULL,
"raw%d", number);
}
__module_get(THIS_MODULE);
device_destroy(raw_class, raw);
device_create(raw_class, NULL, raw, NULL, "raw%d", number);
}
mutex_unlock(&raw_mutex);
return err;
@ -192,18 +188,9 @@ static int bind_set(int number, u64 major, u64 minor)
static int bind_get(int number, dev_t *dev)
{
struct raw_device_data *rawdev;
struct block_device *bdev;
if (number <= 0 || number >= max_raw_minors)
return -EINVAL;
rawdev = &raw_devices[number];
mutex_lock(&raw_mutex);
bdev = rawdev->binding;
*dev = bdev ? bdev->bd_dev : 0;
mutex_unlock(&raw_mutex);
*dev = raw_devices[number].binding;
return 0;
}