From a31713517dac0862a3f0ec9006df9160ce022b0c Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Wed, 5 Jun 2019 08:04:48 -0700 Subject: 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 Signed-off-by: Amir Goldstein Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- mm/filemap.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'mm/filemap.c') diff --git a/mm/filemap.c b/mm/filemap.c index df2006ba0cfa..a38619a4a6af 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -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) -- cgit