blockdev: remove bd_block_size_semaphore again
This reverts the block-device direct access code to the previous
unlocked code, now that fs/buffer.c no longer needs external locking.
With this, fs/block_dev.c is back to the original version, apart from a
whitespace cleanup that I didn't want to revert.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 1a1e5e3..47a949d 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -116,8 +116,6 @@
int set_blocksize(struct block_device *bdev, int size)
{
- struct address_space *mapping;
-
/* Size must be a power of two, and between 512 and PAGE_SIZE */
if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size))
return -EINVAL;
@@ -126,19 +124,6 @@
if (size < bdev_logical_block_size(bdev))
return -EINVAL;
- /* Prevent starting I/O or mapping the device */
- percpu_down_write(&bdev->bd_block_size_semaphore);
-
- /* Check that the block device is not memory mapped */
- mapping = bdev->bd_inode->i_mapping;
- mutex_lock(&mapping->i_mmap_mutex);
- if (mapping_mapped(mapping)) {
- mutex_unlock(&mapping->i_mmap_mutex);
- percpu_up_write(&bdev->bd_block_size_semaphore);
- return -EBUSY;
- }
- mutex_unlock(&mapping->i_mmap_mutex);
-
/* Don't change the size if it is same as current */
if (bdev->bd_block_size != size) {
sync_blockdev(bdev);
@@ -146,9 +131,6 @@
bdev->bd_inode->i_blkbits = blksize_bits(size);
kill_bdev(bdev);
}
-
- percpu_up_write(&bdev->bd_block_size_semaphore);
-
return 0;
}
@@ -459,12 +441,6 @@
struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL);
if (!ei)
return NULL;
-
- if (unlikely(percpu_init_rwsem(&ei->bdev.bd_block_size_semaphore))) {
- kmem_cache_free(bdev_cachep, ei);
- return NULL;
- }
-
return &ei->vfs_inode;
}
@@ -473,8 +449,6 @@
struct inode *inode = container_of(head, struct inode, i_rcu);
struct bdev_inode *bdi = BDEV_I(inode);
- percpu_free_rwsem(&bdi->bdev.bd_block_size_semaphore);
-
kmem_cache_free(bdev_cachep, bdi);
}
@@ -1593,22 +1567,6 @@
return blkdev_ioctl(bdev, mode, cmd, arg);
}
-ssize_t blkdev_aio_read(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs, loff_t pos)
-{
- ssize_t ret;
- struct block_device *bdev = I_BDEV(iocb->ki_filp->f_mapping->host);
-
- percpu_down_read(&bdev->bd_block_size_semaphore);
-
- ret = generic_file_aio_read(iocb, iov, nr_segs, pos);
-
- percpu_up_read(&bdev->bd_block_size_semaphore);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(blkdev_aio_read);
-
/*
* Write data to the block device. Only intended for the block device itself
* and the raw driver which basically is a fake block device.
@@ -1620,16 +1578,12 @@
unsigned long nr_segs, loff_t pos)
{
struct file *file = iocb->ki_filp;
- struct block_device *bdev = I_BDEV(file->f_mapping->host);
struct blk_plug plug;
ssize_t ret;
BUG_ON(iocb->ki_pos != pos);
blk_start_plug(&plug);
-
- percpu_down_read(&bdev->bd_block_size_semaphore);
-
ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
if (ret > 0 || ret == -EIOCBQUEUED) {
ssize_t err;
@@ -1638,62 +1592,11 @@
if (err < 0 && ret > 0)
ret = err;
}
-
- percpu_up_read(&bdev->bd_block_size_semaphore);
-
blk_finish_plug(&plug);
-
return ret;
}
EXPORT_SYMBOL_GPL(blkdev_aio_write);
-static int blkdev_mmap(struct file *file, struct vm_area_struct *vma)
-{
- int ret;
- struct block_device *bdev = I_BDEV(file->f_mapping->host);
-
- percpu_down_read(&bdev->bd_block_size_semaphore);
-
- ret = generic_file_mmap(file, vma);
-
- percpu_up_read(&bdev->bd_block_size_semaphore);
-
- return ret;
-}
-
-static ssize_t blkdev_splice_read(struct file *file, loff_t *ppos,
- struct pipe_inode_info *pipe, size_t len,
- unsigned int flags)
-{
- ssize_t ret;
- struct block_device *bdev = I_BDEV(file->f_mapping->host);
-
- percpu_down_read(&bdev->bd_block_size_semaphore);
-
- ret = generic_file_splice_read(file, ppos, pipe, len, flags);
-
- percpu_up_read(&bdev->bd_block_size_semaphore);
-
- return ret;
-}
-
-static ssize_t blkdev_splice_write(struct pipe_inode_info *pipe,
- struct file *file, loff_t *ppos, size_t len,
- unsigned int flags)
-{
- ssize_t ret;
- struct block_device *bdev = I_BDEV(file->f_mapping->host);
-
- percpu_down_read(&bdev->bd_block_size_semaphore);
-
- ret = generic_file_splice_write(pipe, file, ppos, len, flags);
-
- percpu_up_read(&bdev->bd_block_size_semaphore);
-
- return ret;
-}
-
-
/*
* Try to release a page associated with block device when the system
* is under memory pressure.
@@ -1724,16 +1627,16 @@
.llseek = block_llseek,
.read = do_sync_read,
.write = do_sync_write,
- .aio_read = blkdev_aio_read,
+ .aio_read = generic_file_aio_read,
.aio_write = blkdev_aio_write,
- .mmap = blkdev_mmap,
+ .mmap = generic_file_mmap,
.fsync = blkdev_fsync,
.unlocked_ioctl = block_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = compat_blkdev_ioctl,
#endif
- .splice_read = blkdev_splice_read,
- .splice_write = blkdev_splice_write,
+ .splice_read = generic_file_splice_read,
+ .splice_write = generic_file_splice_write,
};
int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg)