Commit a3171351 authored by Amir Goldstein's avatar Amir Goldstein Committed by Darrick J. Wong
Browse files

vfs: introduce generic_file_rw_checks() 



Factor out helper with some checks on in/out file that are
common to clone_file_range and copy_file_range.

Suggested-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
parent 64bf5ff5

fs/read_write.c

+11 −27
Original line number Diff line number Diff line
@@ -1617,17 +1617,18 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, 
			    struct file *file_out, loff_t pos_out,

			    size_t len, unsigned int flags)

{

	struct inode *inode_in = file_inode(file_in);

	struct inode *inode_out = file_inode(file_out);

	ssize_t ret;



	if (flags != 0)

		return -EINVAL;



	if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))

		return -EISDIR;

	if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))

		return -EINVAL;

	/* this could be relaxed once a method supports cross-fs copies */

	if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)

		return -EXDEV;



	ret = generic_file_rw_checks(file_in, file_out);

	if (unlikely(ret))

		return ret;



	ret = rw_verify_area(READ, file_in, &pos_in, len);

	if (unlikely(ret))
@@ -1637,15 +1638,6 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, 
	if (unlikely(ret))

		return ret;



	if (!(file_in->f_mode & FMODE_READ) ||

	    !(file_out->f_mode & FMODE_WRITE) ||

	    (file_out->f_flags & O_APPEND))

		return -EBADF;



	/* this could be relaxed once a method supports cross-fs copies */

	if (inode_in->i_sb != inode_out->i_sb)

		return -EXDEV;



	if (len == 0)

		return 0;
@@ -2013,29 +2005,21 @@ loff_t do_clone_file_range(struct file *file_in, loff_t pos_in, 
			   struct file *file_out, loff_t pos_out,

			   loff_t len, unsigned int remap_flags)

{

	struct inode *inode_in = file_inode(file_in);

	struct inode *inode_out = file_inode(file_out);

	loff_t ret;



	WARN_ON_ONCE(remap_flags & REMAP_FILE_DEDUP);



	if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))

		return -EISDIR;

	if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))

		return -EINVAL;



	/*

	 * FICLONE/FICLONERANGE ioctls enforce that src and dest files are on

	 * the same mount. Practically, they only need to be on the same file

	 * system.

	 */

	if (inode_in->i_sb != inode_out->i_sb)

	if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)

		return -EXDEV;



	if (!(file_in->f_mode & FMODE_READ) ||

	    !(file_out->f_mode & FMODE_WRITE) ||

	    (file_out->f_flags & O_APPEND))

		return -EBADF;

	ret = generic_file_rw_checks(file_in, file_out);

	if (ret < 0)

		return ret;



	if (!file_in->f_op->remap_file_range)

		return -EOPNOTSUPP;

include/linux/fs.h

+1 −0
Original line number Diff line number Diff line
@@ -3049,6 +3049,7 @@ extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *); 
extern int generic_remap_checks(struct file *file_in, loff_t pos_in,

				struct file *file_out, loff_t pos_out,

				loff_t *count, unsigned int remap_flags);

extern int generic_file_rw_checks(struct file *file_in, struct file *file_out);

extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);

extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *);

extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *);

mm/filemap.c

+24 −0
Original line number Diff line number Diff line
@@ -3041,6 +3041,30 @@ int generic_remap_checks(struct file *file_in, loff_t pos_in, 
	return 0;

}





/*

 * Performs common checks before doing a file copy/clone

 * from @file_in to @file_out.

 */

int generic_file_rw_checks(struct file *file_in, struct file *file_out)

{

	struct inode *inode_in = file_inode(file_in);

	struct inode *inode_out = file_inode(file_out);



	/* Don't copy dirs, pipes, sockets... */

	if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))

		return -EISDIR;

	if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))

		return -EINVAL;



	if (!(file_in->f_mode & FMODE_READ) ||

	    !(file_out->f_mode & FMODE_WRITE) ||

	    (file_out->f_flags & O_APPEND))

		return -EBADF;



	return 0;

}



int pagecache_write_begin(struct file *file, struct address_space *mapping,

				loff_t pos, unsigned len, unsigned flags,

				struct page **pagep, void **fsdata)