bdev->bd_dev = dev;
inode->i_mode = S_IFBLK;
inode->i_rdev = dev;
- inode->i_bdev = bdev;
inode->i_data.a_ops = &def_blk_aops;
mapping_set_gfp_mask(&inode->i_data, GFP_USER);
unlock_new_inode(inode);
{
iput(bdev->bd_inode);
}
-
EXPORT_SYMBOL(bdput);
-static struct block_device *bd_acquire(struct inode *inode)
-{
- struct block_device *bdev;
-
- spin_lock(&bdev_lock);
- bdev = inode->i_bdev;
- if (bdev && !inode_unhashed(bdev->bd_inode)) {
- bdgrab(bdev);
- spin_unlock(&bdev_lock);
- return bdev;
- }
- spin_unlock(&bdev_lock);
-
- /*
- * i_bdev references block device inode that was already shut down
- * (corresponding device got removed). Remove the reference and look
- * up block device inode again just in case new device got
- * reestablished under the same device number.
- */
- if (bdev)
- bd_forget(inode);
-
- bdev = bdget(inode->i_rdev);
- if (bdev) {
- spin_lock(&bdev_lock);
- if (!inode->i_bdev) {
- /*
- * We take an additional reference to bd_inode,
- * and it's released in clear_inode() of inode.
- * So, we can access it via ->i_mapping always
- * without igrab().
- */
- bdgrab(bdev);
- inode->i_bdev = bdev;
- inode->i_mapping = bdev->bd_inode->i_mapping;
- }
- spin_unlock(&bdev_lock);
- }
- return bdev;
-}
-
-/* Call when you free inode */
-
-void bd_forget(struct inode *inode)
-{
- struct block_device *bdev = NULL;
-
- spin_lock(&bdev_lock);
- if (!sb_is_blkdev_sb(inode->i_sb))
- bdev = inode->i_bdev;
- inode->i_bdev = NULL;
- inode->i_mapping = &inode->i_data;
- spin_unlock(&bdev_lock);
-
- if (bdev)
- bdput(bdev);
-}
-
/**
* bd_may_claim - test whether a block device can be claimed
* @bdev: block device of interest
}
/**
- * blkdev_get - open a block device
- * @bdev: block_device to open
+ * blkdev_get_by_dev - open a block device by device number
+ * @dev: device number of block device to open
* @mode: FMODE_* mask
* @holder: exclusive holder identifier
*
- * Open @bdev with @mode. If @mode includes %FMODE_EXCL, @bdev is
- * open with exclusive access. Specifying %FMODE_EXCL with %NULL
- * @holder is invalid. Exclusive opens may nest for the same @holder.
+ * Open the block device described by device number @dev. If @mode includes
+ * %FMODE_EXCL, the block device is opened with exclusive access. Specifying
+ * %FMODE_EXCL with a %NULL @holder is invalid. Exclusive opens may nest for
+ * the same @holder.
*
- * On success, the reference count of @bdev is unchanged. On failure,
- * @bdev is put.
+ * Use this interface ONLY if you really do not have anything better - i.e. when
+ * you are behind a truly sucky interface and all you are given is a device
+ * number. Everything else should use blkdev_get_by_path().
*
* CONTEXT:
* Might sleep.
*
* RETURNS:
- * 0 on success, -errno on failure.
+ * Reference to the block_device on success, ERR_PTR(-errno) on failure.
*/
-static int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
+struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder)
{
struct block_device *claiming;
bool unblock_events = true;
+ struct block_device *bdev;
struct gendisk *disk;
- int perm = 0;
int partno;
int ret;
- if (mode & FMODE_READ)
- perm |= MAY_READ;
- if (mode & FMODE_WRITE)
- perm |= MAY_WRITE;
- ret = devcgroup_inode_permission(bdev->bd_inode, perm);
+ ret = devcgroup_check_permission(DEVCG_DEV_BLOCK,
+ MAJOR(dev), MINOR(dev),
+ ((mode & FMODE_READ) ? DEVCG_ACC_READ : 0) |
+ ((mode & FMODE_WRITE) ? DEVCG_ACC_WRITE : 0));
if (ret)
- goto bdput;
+ return ERR_PTR(ret);
+
+ bdev = bdget(dev);
+ if (!bdev)
+ return ERR_PTR(-ENOMEM);
/*
* If we lost a race with 'disk' being deleted, try again. See md.c.
if (ret == -ERESTARTSYS)
goto retry;
bdput:
- if (ret)
+ if (ret) {
bdput(bdev);
- return ret;
+ return ERR_PTR(ret);
+ }
+ return bdev;
}
+EXPORT_SYMBOL(blkdev_get_by_dev);
/**
* blkdev_get_by_path - open a block device by name
* @mode: FMODE_* mask
* @holder: exclusive holder identifier
*
- * Open the blockdevice described by the device file at @path. @mode
- * and @holder are identical to blkdev_get().
- *
- * On success, the returned block_device has reference count of one.
+ * Open the block device described by the device file at @path. If @mode
+ * includes %FMODE_EXCL, the block device is opened with exclusive access.
+ * Specifying %FMODE_EXCL with a %NULL @holder is invalid. Exclusive opens may
+ * nest for the same @holder.
*
* CONTEXT:
* Might sleep.
*
* RETURNS:
- * Pointer to block_device on success, ERR_PTR(-errno) on failure.
+ * Reference to the block_device on success, ERR_PTR(-errno) on failure.
*/
struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
void *holder)
{
struct block_device *bdev;
- int err;
-
- bdev = lookup_bdev(path);
- if (IS_ERR(bdev))
- return bdev;
+ dev_t dev;
+ int error;
- err = blkdev_get(bdev, mode, holder);
- if (err)
- return ERR_PTR(err);
+ error = lookup_bdev(path, &dev);
+ if (error)
+ return ERR_PTR(error);
- if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) {
+ bdev = blkdev_get_by_dev(dev, mode, holder);
+ if (!IS_ERR(bdev) && (mode & FMODE_WRITE) && bdev_read_only(bdev)) {
blkdev_put(bdev, mode);
return ERR_PTR(-EACCES);
}
}
EXPORT_SYMBOL(blkdev_get_by_path);
-/**
- * blkdev_get_by_dev - open a block device by device number
- * @dev: device number of block device to open
- * @mode: FMODE_* mask
- * @holder: exclusive holder identifier
- *
- * Open the blockdevice described by device number @dev. @mode and
- * @holder are identical to blkdev_get().
- *
- * Use it ONLY if you really do not have anything better - i.e. when
- * you are behind a truly sucky interface and all you are given is a
- * device number. _Never_ to be used for internal purposes. If you
- * ever need it - reconsider your API.
- *
- * On success, the returned block_device has reference count of one.
- *
- * CONTEXT:
- * Might sleep.
- *
- * RETURNS:
- * Pointer to block_device on success, ERR_PTR(-errno) on failure.
- */
-struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder)
-{
- struct block_device *bdev;
- int err;
-
- bdev = bdget(dev);
- if (!bdev)
- return ERR_PTR(-ENOMEM);
-
- err = blkdev_get(bdev, mode, holder);
- if (err)
- return ERR_PTR(err);
-
- return bdev;
-}
-EXPORT_SYMBOL(blkdev_get_by_dev);
-
static int blkdev_open(struct inode * inode, struct file * filp)
{
struct block_device *bdev;
if ((filp->f_flags & O_ACCMODE) == 3)
filp->f_mode |= FMODE_WRITE_IOCTL;
- bdev = bd_acquire(inode);
- if (bdev == NULL)
- return -ENOMEM;
-
+ bdev = blkdev_get_by_dev(inode->i_rdev, filp->f_mode, filp);
+ if (IS_ERR(bdev))
+ return PTR_ERR(bdev);
filp->f_mapping = bdev->bd_inode->i_mapping;
filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping);
-
- return blkdev_get(bdev, filp->f_mode, filp);
+ return 0;
}
static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
* namespace if possible and return it. Return ERR_PTR(error)
* otherwise.
*/
-struct block_device *lookup_bdev(const char *pathname)
+int lookup_bdev(const char *pathname, dev_t *dev)
{
- struct block_device *bdev;
struct inode *inode;
struct path path;
int error;
if (!pathname || !*pathname)
- return ERR_PTR(-EINVAL);
+ return -EINVAL;
error = kern_path(pathname, LOOKUP_FOLLOW, &path);
if (error)
- return ERR_PTR(error);
+ return error;
inode = d_backing_inode(path.dentry);
error = -ENOTBLK;
if (!S_ISBLK(inode->i_mode))
- goto fail;
+ goto out_path_put;
error = -EACCES;
if (!may_open_dev(&path))
- goto fail;
- error = -ENOMEM;
- bdev = bd_acquire(inode);
- if (!bdev)
- goto fail;
-out:
+ goto out_path_put;
+
+ *dev = inode->i_rdev;
+ error = 0;
+out_path_put:
path_put(&path);
- return bdev;
-fail:
- bdev = ERR_PTR(error);
- goto out;
+ return error;
}
EXPORT_SYMBOL(lookup_bdev);
projects / linux-2.6-microblaze.git / blobdiff