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: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Amir Goldstein 2019-06-05 08:04:48 -07:00 committed by Darrick J. Wong
parent 64bf5ff58d
commit a31713517d
3 changed files with 36 additions and 27 deletions

View file

@ -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)