Re: [PATCH v4 3/9] btrfs: add .copy_file_range file operation

[Anna Schumaker <Anna.Schumaker-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org>]

On 09/29/2015 11:20 PM, Zhao Lei wrote:
> Hi, Anna Schumaker
> 
>> -----Original Message-----
>> From: linux-btrfs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>> [mailto:linux-btrfs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org] On Behalf Of Anna Schumaker
>> Sent: Wednesday, September 30, 2015 2:05 AM
>> To: linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; linux-btrfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org;
>> linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; zab-ugsP4Wv/S6ZeoWH0uzbU5w@public.gmane.org;
>> viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org; clm-b10kYP2dOMg@public.gmane.org; darrick.wong-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org;
>> mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org; andros-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org; hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org
>> Subject: [PATCH v4 3/9] btrfs: add .copy_file_range file operation
>>
>> From: Zach Brown <zab-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>>
>> This rearranges the existing COPY_RANGE ioctl implementation so that
>> the .copy_file_range file operation can call the core loop that copies file data
>> extent items.
>>
>> The extent copying loop is lifted up into its own function.  It retains the core
>> btrfs error checks that should be shared.
>>
>> Signed-off-by: Zach Brown <zab-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>> Signed-off-by: Anna Schumaker <Anna.Schumaker-ZwjVKphTwtPQT0dZR+AlfA@public.gmane.org>
>> Reviewed-by: Josef Bacik <jbacik-b10kYP2dOMg@public.gmane.org>
>> Reviewed-by: David Sterba <dsterba-IBi9RG/b67k@public.gmane.org>
>> ---
>>  fs/btrfs/ctree.h |  3 ++
>>  fs/btrfs/file.c  |  1 +
>>  fs/btrfs/ioctl.c | 91 ++++++++++++++++++++++++++++++++------------------------
>>  3 files changed, 56 insertions(+), 39 deletions(-)
>>
>> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 938efe3..5d06a4f 100644
>> --- a/fs/btrfs/ctree.h
>> +++ b/fs/btrfs/ctree.h
>> @@ -3996,6 +3996,9 @@ int btrfs_dirty_pages(struct btrfs_root *root, struct
>> inode *inode,
>>  		      loff_t pos, size_t write_bytes,
>>  		      struct extent_state **cached);
>>  int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end);
>> +ssize_t btrfs_copy_file_range(struct file *file_in, loff_t pos_in,
>> +			      struct file *file_out, loff_t pos_out,
>> +			      size_t len, int flags);
>>
> 
> It is different with declaration:
> ssize_t (*copy_file_range)(struct file *, loff_t, struct file *, loff_t, size_t, unsigned int);
> 
> (flags changed from unsigned int to int)
> 
>>  /* tree-defrag.c */
>>  int btrfs_defrag_leaves(struct btrfs_trans_handle *trans, diff --git
>> a/fs/btrfs/file.c b/fs/btrfs/file.c index b823fac..b05449c 100644
>> --- a/fs/btrfs/file.c
>> +++ b/fs/btrfs/file.c
>> @@ -2816,6 +2816,7 @@ const struct file_operations btrfs_file_operations =
>> {  #ifdef CONFIG_COMPAT
>>  	.compat_ioctl	= btrfs_ioctl,
>>  #endif
>> +	.copy_file_range = btrfs_copy_file_range,
> 
> And cause compiler warning at this line:
> fs/btrfs/file.c:2819: warning: initialization from incompatible pointer type   
> 
> Small problem, but better to fix.

Thanks!  I must have missed it when I switched flags to unsigned int.

Anna

> 
> Thanks
> Zhaolei
> 
>>  };
>>
>>  void btrfs_auto_defrag_exit(void)
>> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 0adf542..4311554 100644
>> --- a/fs/btrfs/ioctl.c
>> +++ b/fs/btrfs/ioctl.c
>> @@ -3727,17 +3727,16 @@ out:
>>  	return ret;
>>  }
>>
>> -static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
>> -				       u64 off, u64 olen, u64 destoff)
>> +static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
>> +					u64 off, u64 olen, u64 destoff)
>>  {
>>  	struct inode *inode = file_inode(file);
>> +	struct inode *src = file_inode(file_src);
>>  	struct btrfs_root *root = BTRFS_I(inode)->root;
>> -	struct fd src_file;
>> -	struct inode *src;
>>  	int ret;
>>  	u64 len = olen;
>>  	u64 bs = root->fs_info->sb->s_blocksize;
>> -	int same_inode = 0;
>> +	int same_inode = src == inode;
>>
>>  	/*
>>  	 * TODO:
>> @@ -3750,49 +3749,20 @@ static noinline long btrfs_ioctl_clone(struct file
>> *file, unsigned long srcfd,
>>  	 *   be either compressed or non-compressed.
>>  	 */
>>
>> -	/* the destination must be opened for writing */
>> -	if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
>> -		return -EINVAL;
>> -
>>  	if (btrfs_root_readonly(root))
>>  		return -EROFS;
>>
>> -	ret = mnt_want_write_file(file);
>> -	if (ret)
>> -		return ret;
>> -
>> -	src_file = fdget(srcfd);
>> -	if (!src_file.file) {
>> -		ret = -EBADF;
>> -		goto out_drop_write;
>> -	}
>> -
>> -	ret = -EXDEV;
>> -	if (src_file.file->f_path.mnt != file->f_path.mnt)
>> -		goto out_fput;
>> -
>> -	src = file_inode(src_file.file);
>> -
>> -	ret = -EINVAL;
>> -	if (src == inode)
>> -		same_inode = 1;
>> -
>> -	/* the src must be open for reading */
>> -	if (!(src_file.file->f_mode & FMODE_READ))
>> -		goto out_fput;
>> +	if (file_src->f_path.mnt != file->f_path.mnt ||
>> +	    src->i_sb != inode->i_sb)
>> +		return -EXDEV;
>>
>>  	/* don't make the dst file partly checksummed */
>>  	if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
>>  	    (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
>> -		goto out_fput;
>> +		return -EINVAL;
>>
>> -	ret = -EISDIR;
>>  	if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
>> -		goto out_fput;
>> -
>> -	ret = -EXDEV;
>> -	if (src->i_sb != inode->i_sb)
>> -		goto out_fput;
>> +		return -EISDIR;
>>
>>  	if (!same_inode) {
>>  		btrfs_double_inode_lock(src, inode);
>> @@ -3869,6 +3839,49 @@ out_unlock:
>>  		btrfs_double_inode_unlock(src, inode);
>>  	else
>>  		mutex_unlock(&src->i_mutex);
>> +	return ret;
>> +}
>> +
>> +ssize_t btrfs_copy_file_range(struct file *file_in, loff_t pos_in,
>> +			      struct file *file_out, loff_t pos_out,
>> +			      size_t len, int flags)
>> +{
>> +	ssize_t ret;
>> +
>> +	ret = btrfs_clone_files(file_out, file_in, pos_in, len, pos_out);
>> +	if (ret == 0)
>> +		ret = len;
>> +	return ret;
>> +}
>> +
>> +static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
>> +				       u64 off, u64 olen, u64 destoff) {
>> +	struct fd src_file;
>> +	int ret;
>> +
>> +	/* the destination must be opened for writing */
>> +	if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
>> +		return -EINVAL;
>> +
>> +	ret = mnt_want_write_file(file);
>> +	if (ret)
>> +		return ret;
>> +
>> +	src_file = fdget(srcfd);
>> +	if (!src_file.file) {
>> +		ret = -EBADF;
>> +		goto out_drop_write;
>> +	}
>> +
>> +	/* the src must be open for reading */
>> +	if (!(src_file.file->f_mode & FMODE_READ)) {
>> +		ret = -EINVAL;
>> +		goto out_fput;
>> +	}
>> +
>> +	ret = btrfs_clone_files(file, src_file.file, off, olen, destoff);
>> +
>>  out_fput:
>>  	fdput(src_file);
>>  out_drop_write:
>> --
>> 2.5.3
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body
>> of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at
>> http://vger.kernel.org/majordomo-info.html
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>