vfs: introduce generic_file_rw_checks() (a3171351) · Commits · 戴 / test

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)

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