mirror of https://gitee.com/openkylin/linux.git
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>
This commit is contained in:
Linus Torvalds
parent
45bce8f3e3
commit
1e8b33328a
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@ -285,7 +285,7 @@ static long raw_ctl_compat_ioctl(struct file *file, unsigned int cmd,
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static const struct file_operations raw_fops = {
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.read = do_sync_read,
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.aio_read = blkdev_aio_read,
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.aio_read = generic_file_aio_read,
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.write = do_sync_write,
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.aio_write = blkdev_aio_write,
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.fsync = blkdev_fsync,
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105
fs/block_dev.c
105
fs/block_dev.c
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@ -116,8 +116,6 @@ EXPORT_SYMBOL(invalidate_bdev);
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int set_blocksize(struct block_device *bdev, int size)
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{
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struct address_space *mapping;
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/* Size must be a power of two, and between 512 and PAGE_SIZE */
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if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size))
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return -EINVAL;
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@ -126,19 +124,6 @@ int set_blocksize(struct block_device *bdev, int size)
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if (size < bdev_logical_block_size(bdev))
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return -EINVAL;
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/* Prevent starting I/O or mapping the device */
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percpu_down_write(&bdev->bd_block_size_semaphore);
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/* Check that the block device is not memory mapped */
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mapping = bdev->bd_inode->i_mapping;
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mutex_lock(&mapping->i_mmap_mutex);
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if (mapping_mapped(mapping)) {
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mutex_unlock(&mapping->i_mmap_mutex);
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percpu_up_write(&bdev->bd_block_size_semaphore);
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return -EBUSY;
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}
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mutex_unlock(&mapping->i_mmap_mutex);
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/* Don't change the size if it is same as current */
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if (bdev->bd_block_size != size) {
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sync_blockdev(bdev);
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@ -146,9 +131,6 @@ int set_blocksize(struct block_device *bdev, int size)
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bdev->bd_inode->i_blkbits = blksize_bits(size);
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kill_bdev(bdev);
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}
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percpu_up_write(&bdev->bd_block_size_semaphore);
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return 0;
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}
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@ -459,12 +441,6 @@ static struct inode *bdev_alloc_inode(struct super_block *sb)
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struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL);
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if (!ei)
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return NULL;
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if (unlikely(percpu_init_rwsem(&ei->bdev.bd_block_size_semaphore))) {
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kmem_cache_free(bdev_cachep, ei);
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return NULL;
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}
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return &ei->vfs_inode;
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}
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@ -473,8 +449,6 @@ static void bdev_i_callback(struct rcu_head *head)
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struct inode *inode = container_of(head, struct inode, i_rcu);
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struct bdev_inode *bdi = BDEV_I(inode);
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percpu_free_rwsem(&bdi->bdev.bd_block_size_semaphore);
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kmem_cache_free(bdev_cachep, bdi);
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}
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@ -1593,22 +1567,6 @@ static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
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return blkdev_ioctl(bdev, mode, cmd, arg);
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}
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ssize_t blkdev_aio_read(struct kiocb *iocb, const struct iovec *iov,
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unsigned long nr_segs, loff_t pos)
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{
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ssize_t ret;
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struct block_device *bdev = I_BDEV(iocb->ki_filp->f_mapping->host);
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percpu_down_read(&bdev->bd_block_size_semaphore);
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ret = generic_file_aio_read(iocb, iov, nr_segs, pos);
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percpu_up_read(&bdev->bd_block_size_semaphore);
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return ret;
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}
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EXPORT_SYMBOL_GPL(blkdev_aio_read);
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/*
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* Write data to the block device. Only intended for the block device itself
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* and the raw driver which basically is a fake block device.
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@ -1620,16 +1578,12 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
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unsigned long nr_segs, loff_t pos)
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{
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struct file *file = iocb->ki_filp;
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struct block_device *bdev = I_BDEV(file->f_mapping->host);
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struct blk_plug plug;
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ssize_t ret;
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BUG_ON(iocb->ki_pos != pos);
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blk_start_plug(&plug);
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percpu_down_read(&bdev->bd_block_size_semaphore);
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ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
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if (ret > 0 || ret == -EIOCBQUEUED) {
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ssize_t err;
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@ -1638,62 +1592,11 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
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if (err < 0 && ret > 0)
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ret = err;
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}
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percpu_up_read(&bdev->bd_block_size_semaphore);
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blk_finish_plug(&plug);
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return ret;
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}
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EXPORT_SYMBOL_GPL(blkdev_aio_write);
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static int blkdev_mmap(struct file *file, struct vm_area_struct *vma)
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{
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int ret;
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struct block_device *bdev = I_BDEV(file->f_mapping->host);
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percpu_down_read(&bdev->bd_block_size_semaphore);
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ret = generic_file_mmap(file, vma);
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percpu_up_read(&bdev->bd_block_size_semaphore);
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return ret;
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}
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static ssize_t blkdev_splice_read(struct file *file, loff_t *ppos,
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struct pipe_inode_info *pipe, size_t len,
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unsigned int flags)
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{
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ssize_t ret;
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struct block_device *bdev = I_BDEV(file->f_mapping->host);
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percpu_down_read(&bdev->bd_block_size_semaphore);
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ret = generic_file_splice_read(file, ppos, pipe, len, flags);
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percpu_up_read(&bdev->bd_block_size_semaphore);
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return ret;
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}
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static ssize_t blkdev_splice_write(struct pipe_inode_info *pipe,
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struct file *file, loff_t *ppos, size_t len,
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unsigned int flags)
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{
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ssize_t ret;
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struct block_device *bdev = I_BDEV(file->f_mapping->host);
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percpu_down_read(&bdev->bd_block_size_semaphore);
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ret = generic_file_splice_write(pipe, file, ppos, len, flags);
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percpu_up_read(&bdev->bd_block_size_semaphore);
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return ret;
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}
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/*
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* Try to release a page associated with block device when the system
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* is under memory pressure.
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@ -1724,16 +1627,16 @@ const struct file_operations def_blk_fops = {
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.llseek = block_llseek,
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.read = do_sync_read,
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.write = do_sync_write,
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.aio_read = blkdev_aio_read,
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.aio_read = generic_file_aio_read,
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.aio_write = blkdev_aio_write,
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.mmap = blkdev_mmap,
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.mmap = generic_file_mmap,
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.fsync = blkdev_fsync,
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.unlocked_ioctl = block_ioctl,
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#ifdef CONFIG_COMPAT
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.compat_ioctl = compat_blkdev_ioctl,
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#endif
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.splice_read = blkdev_splice_read,
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.splice_write = blkdev_splice_write,
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.splice_read = generic_file_splice_read,
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.splice_write = generic_file_splice_write,
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};
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int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg)
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@ -462,8 +462,6 @@ struct block_device {
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int bd_fsfreeze_count;
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/* Mutex for freeze */
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struct mutex bd_fsfreeze_mutex;
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/* A semaphore that prevents I/O while block size is being changed */
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struct percpu_rw_semaphore bd_block_size_semaphore;
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};
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/*
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@ -2379,8 +2377,6 @@ extern int generic_segment_checks(const struct iovec *iov,
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unsigned long *nr_segs, size_t *count, int access_flags);
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/* fs/block_dev.c */
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extern ssize_t blkdev_aio_read(struct kiocb *iocb, const struct iovec *iov,
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unsigned long nr_segs, loff_t pos);
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extern ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
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unsigned long nr_segs, loff_t pos);
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extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
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