}
EXPORT_SYMBOL(I_BDEV);
+struct block_device *file_bdev(struct file *bdev_file)
+{
+ return I_BDEV(bdev_file->f_mapping->host);
+}
+EXPORT_SYMBOL(file_bdev);
+
static void bdev_write_inode(struct block_device *bdev)
{
struct inode *inode = bdev->bd_inode;
};
struct super_block *blockdev_superblock __ro_after_init;
+struct vfsmount *blockdev_mnt __ro_after_init;
EXPORT_SYMBOL_GPL(blockdev_superblock);
void __init bdev_cache_init(void)
{
int err;
- static struct vfsmount *bd_mnt __ro_after_init;
bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode),
0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
- SLAB_MEM_SPREAD|SLAB_ACCOUNT|SLAB_PANIC),
+ SLAB_ACCOUNT|SLAB_PANIC),
init_once);
err = register_filesystem(&bd_type);
if (err)
panic("Cannot register bdev pseudo-fs");
- bd_mnt = kern_mount(&bd_type);
- if (IS_ERR(bd_mnt))
+ blockdev_mnt = kern_mount(&bd_type);
+ if (IS_ERR(blockdev_mnt))
panic("Cannot create bdev pseudo-fs");
- blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */
+ blockdev_superblock = blockdev_mnt->mnt_sb; /* For writeback */
}
struct block_device *bdev_alloc(struct gendisk *disk, u8 partno)
return ret;
}
+int bdev_permission(dev_t dev, blk_mode_t mode, void *holder)
+{
+ int ret;
+
+ ret = devcgroup_check_permission(DEVCG_DEV_BLOCK,
+ MAJOR(dev), MINOR(dev),
+ ((mode & BLK_OPEN_READ) ? DEVCG_ACC_READ : 0) |
+ ((mode & BLK_OPEN_WRITE) ? DEVCG_ACC_WRITE : 0));
+ if (ret)
+ return ret;
+
+ /* Blocking writes requires exclusive opener */
+ if (mode & BLK_OPEN_RESTRICT_WRITES && !holder)
+ return -EINVAL;
+
+ /*
+ * We're using error pointers to indicate to ->release() when we
+ * failed to open that block device. Also this doesn't make sense.
+ */
+ if (WARN_ON_ONCE(IS_ERR(holder)))
+ return -EINVAL;
+
+ return 0;
+}
+
static void blkdev_put_part(struct block_device *part)
{
struct block_device *whole = bdev_whole(part);
bdev->bd_writers++;
}
-static void bdev_yield_write_access(struct block_device *bdev, blk_mode_t mode)
+static void bdev_yield_write_access(struct file *bdev_file)
{
+ struct block_device *bdev;
+
if (bdev_allow_write_mounted)
return;
+ bdev = file_bdev(bdev_file);
/* Yield exclusive or shared write access. */
- if (mode & BLK_OPEN_RESTRICT_WRITES)
- bdev_unblock_writes(bdev);
- else if (mode & BLK_OPEN_WRITE)
- bdev->bd_writers--;
+ if (bdev_file->f_mode & FMODE_WRITE) {
+ if (bdev_writes_blocked(bdev))
+ bdev_unblock_writes(bdev);
+ else
+ bdev->bd_writers--;
+ }
}
/**
- * bdev_open_by_dev - open a block device by device number
- * @dev: device number of block device to open
+ * bdev_open - open a block device
+ * @bdev: block device to open
* @mode: open mode (BLK_OPEN_*)
* @holder: exclusive holder identifier
* @hops: holder operations
+ * @bdev_file: file for the block device
*
- * Open the block device described by device number @dev. If @holder is not
- * %NULL, the block device is opened with exclusive access. Exclusive opens may
- * nest for the same @holder.
- *
- * 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 bdev_open_by_path().
+ * Open the block device. If @holder is not %NULL, the block device is opened
+ * with exclusive access. Exclusive opens may nest for the same @holder.
*
* CONTEXT:
* Might sleep.
*
* RETURNS:
- * Handle with a reference to the block_device on success, ERR_PTR(-errno) on
- * failure.
+ * zero on success, -errno on failure.
*/
-struct bdev_handle *bdev_open_by_dev(dev_t dev, blk_mode_t mode, void *holder,
- const struct blk_holder_ops *hops)
+int bdev_open(struct block_device *bdev, blk_mode_t mode, void *holder,
+ const struct blk_holder_ops *hops, struct file *bdev_file)
{
- struct bdev_handle *handle = kmalloc(sizeof(struct bdev_handle),
- GFP_KERNEL);
- struct block_device *bdev;
bool unblock_events = true;
- struct gendisk *disk;
+ struct gendisk *disk = bdev->bd_disk;
int ret;
- if (!handle)
- return ERR_PTR(-ENOMEM);
-
- ret = devcgroup_check_permission(DEVCG_DEV_BLOCK,
- MAJOR(dev), MINOR(dev),
- ((mode & BLK_OPEN_READ) ? DEVCG_ACC_READ : 0) |
- ((mode & BLK_OPEN_WRITE) ? DEVCG_ACC_WRITE : 0));
- if (ret)
- goto free_handle;
-
- /* Blocking writes requires exclusive opener */
- if (mode & BLK_OPEN_RESTRICT_WRITES && !holder) {
- ret = -EINVAL;
- goto free_handle;
- }
-
- bdev = blkdev_get_no_open(dev);
- if (!bdev) {
- ret = -ENXIO;
- goto free_handle;
- }
- disk = bdev->bd_disk;
-
if (holder) {
mode |= BLK_OPEN_EXCL;
ret = bd_prepare_to_claim(bdev, holder, hops);
if (ret)
- goto put_blkdev;
+ return ret;
} else {
- if (WARN_ON_ONCE(mode & BLK_OPEN_EXCL)) {
- ret = -EIO;
- goto put_blkdev;
- }
+ if (WARN_ON_ONCE(mode & BLK_OPEN_EXCL))
+ return -EIO;
}
disk_block_events(disk);
if (unblock_events)
disk_unblock_events(disk);
- handle->bdev = bdev;
- handle->holder = holder;
- handle->mode = mode;
- return handle;
+
+ bdev_file->f_flags |= O_LARGEFILE;
+ bdev_file->f_mode |= FMODE_BUF_RASYNC | FMODE_CAN_ODIRECT;
+ if (bdev_nowait(bdev))
+ bdev_file->f_mode |= FMODE_NOWAIT;
+ bdev_file->f_mapping = bdev->bd_inode->i_mapping;
+ bdev_file->f_wb_err = filemap_sample_wb_err(bdev_file->f_mapping);
+ bdev_file->private_data = holder;
+
+ return 0;
put_module:
module_put(disk->fops->owner);
abort_claiming:
bd_abort_claiming(bdev, holder);
mutex_unlock(&disk->open_mutex);
disk_unblock_events(disk);
-put_blkdev:
- blkdev_put_no_open(bdev);
-free_handle:
- kfree(handle);
- return ERR_PTR(ret);
+ return ret;
}
-EXPORT_SYMBOL(bdev_open_by_dev);
-/**
- * bdev_open_by_path - open a block device by name
- * @path: path to the block device to open
- * @mode: open mode (BLK_OPEN_*)
- * @holder: exclusive holder identifier
- * @hops: holder operations
- *
- * Open the block device described by the device file at @path. If @holder is
- * not %NULL, the block device is opened with exclusive access. Exclusive opens
- * may nest for the same @holder.
- *
- * CONTEXT:
- * Might sleep.
+/*
+ * If BLK_OPEN_WRITE_IOCTL is set then this is a historical quirk
+ * associated with the floppy driver where it has allowed ioctls if the
+ * file was opened for writing, but does not allow reads or writes.
+ * Make sure that this quirk is reflected in @f_flags.
*
- * RETURNS:
- * Handle with a reference to the block_device on success, ERR_PTR(-errno) on
- * failure.
+ * It can also happen if a block device is opened as O_RDWR | O_WRONLY.
*/
-struct bdev_handle *bdev_open_by_path(const char *path, blk_mode_t mode,
- void *holder, const struct blk_holder_ops *hops)
+static unsigned blk_to_file_flags(blk_mode_t mode)
+{
+ unsigned int flags = 0;
+
+ if ((mode & (BLK_OPEN_READ | BLK_OPEN_WRITE)) ==
+ (BLK_OPEN_READ | BLK_OPEN_WRITE))
+ flags |= O_RDWR;
+ else if (mode & BLK_OPEN_WRITE_IOCTL)
+ flags |= O_RDWR | O_WRONLY;
+ else if (mode & BLK_OPEN_WRITE)
+ flags |= O_WRONLY;
+ else if (mode & BLK_OPEN_READ)
+ flags |= O_RDONLY; /* homeopathic, because O_RDONLY is 0 */
+ else
+ WARN_ON_ONCE(true);
+
+ if (mode & BLK_OPEN_NDELAY)
+ flags |= O_NDELAY;
+
+ return flags;
+}
+
+struct file *bdev_file_open_by_dev(dev_t dev, blk_mode_t mode, void *holder,
+ const struct blk_holder_ops *hops)
{
- struct bdev_handle *handle;
+ struct file *bdev_file;
+ struct block_device *bdev;
+ unsigned int flags;
+ int ret;
+
+ ret = bdev_permission(dev, mode, holder);
+ if (ret)
+ return ERR_PTR(ret);
+
+ bdev = blkdev_get_no_open(dev);
+ if (!bdev)
+ return ERR_PTR(-ENXIO);
+
+ flags = blk_to_file_flags(mode);
+ bdev_file = alloc_file_pseudo_noaccount(bdev->bd_inode,
+ blockdev_mnt, "", flags | O_LARGEFILE, &def_blk_fops);
+ if (IS_ERR(bdev_file)) {
+ blkdev_put_no_open(bdev);
+ return bdev_file;
+ }
+ ihold(bdev->bd_inode);
+
+ ret = bdev_open(bdev, mode, holder, hops, bdev_file);
+ if (ret) {
+ /* We failed to open the block device. Let ->release() know. */
+ bdev_file->private_data = ERR_PTR(ret);
+ fput(bdev_file);
+ return ERR_PTR(ret);
+ }
+ return bdev_file;
+}
+EXPORT_SYMBOL(bdev_file_open_by_dev);
+
+struct file *bdev_file_open_by_path(const char *path, blk_mode_t mode,
+ void *holder,
+ const struct blk_holder_ops *hops)
+{
+ struct file *file;
dev_t dev;
int error;
if (error)
return ERR_PTR(error);
- handle = bdev_open_by_dev(dev, mode, holder, hops);
- if (!IS_ERR(handle) && (mode & BLK_OPEN_WRITE) &&
- bdev_read_only(handle->bdev)) {
- bdev_release(handle);
- return ERR_PTR(-EACCES);
+ file = bdev_file_open_by_dev(dev, mode, holder, hops);
+ if (!IS_ERR(file) && (mode & BLK_OPEN_WRITE)) {
+ if (bdev_read_only(file_bdev(file))) {
+ fput(file);
+ file = ERR_PTR(-EACCES);
+ }
}
- return handle;
+ return file;
}
-EXPORT_SYMBOL(bdev_open_by_path);
+EXPORT_SYMBOL(bdev_file_open_by_path);
-void bdev_release(struct bdev_handle *handle)
+void bdev_release(struct file *bdev_file)
{
- struct block_device *bdev = handle->bdev;
+ struct block_device *bdev = file_bdev(bdev_file);
+ void *holder = bdev_file->private_data;
struct gendisk *disk = bdev->bd_disk;
+ /* We failed to open that block device. */
+ if (IS_ERR(holder))
+ goto put_no_open;
+
/*
* Sync early if it looks like we're the last one. If someone else
* opens the block device between now and the decrement of bd_openers
sync_blockdev(bdev);
mutex_lock(&disk->open_mutex);
- bdev_yield_write_access(bdev, handle->mode);
+ bdev_yield_write_access(bdev_file);
- if (handle->holder)
- bd_end_claim(bdev, handle->holder);
+ if (holder)
+ bd_end_claim(bdev, holder);
/*
* Trigger event checking and tell drivers to flush MEDIA_CHANGE
mutex_unlock(&disk->open_mutex);
module_put(disk->fops->owner);
+put_no_open:
blkdev_put_no_open(bdev);
- kfree(handle);
}
-EXPORT_SYMBOL(bdev_release);
/**
* lookup_bdev() - Look up a struct block_device by name.
projects / linux-2.6-block.git / blobdiff