Commit 8dde90bc authored by Darrick J. Wong's avatar Darrick J. Wong Committed by Dave Chinner
Browse files

vfs: remap helper should update destination inode metadata 



Extend generic_remap_file_range_prep to handle inode metadata updates
when remapping into a file.  If the operation can possibly alter the
file contents, we must update the ctime and mtime and remove security
privileges, just like we do for regular file writes.

Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
parent 3d28193e

fs/read_write.c

+19 −0
Original line number Original line Diff line number Diff line
@@ -1820,6 +1820,25 @@ int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, 
	if (ret)

	if (ret)

		return ret;

		return ret;





	/* If can't alter the file contents, we're done. */

	if (!(remap_flags & REMAP_FILE_DEDUP)) {

		/* Update the timestamps, since we can alter file contents. */

		if (!(file_out->f_mode & FMODE_NOCMTIME)) {

			ret = file_update_time(file_out);

			if (ret)

				return ret;

		}



		/*

		 * Clear the security bits if the process is not being run by

		 * root.  This keeps people from modifying setuid and setgid

		 * binaries.

		 */

		ret = file_remove_privs(file_out);

		if (ret)

			return ret;

	}



	return 1;

	return 1;

}

}

EXPORT_SYMBOL(generic_remap_file_range_prep);

EXPORT_SYMBOL(generic_remap_file_range_prep);

fs/xfs/xfs_reflink.c

+0 −23
Original line number Original line Diff line number Diff line
@@ -1372,29 +1372,6 @@ xfs_reflink_remap_prep( 
	truncate_inode_pages_range(&inode_out->i_data, pos_out,

	truncate_inode_pages_range(&inode_out->i_data, pos_out,

				   PAGE_ALIGN(pos_out + *len) - 1);

				   PAGE_ALIGN(pos_out + *len) - 1);





	/* If we're altering the file contents... */

	if (!(remap_flags & REMAP_FILE_DEDUP)) {

		/*

		 * ...update the timestamps (which will grab the ilock again

		 * from xfs_fs_dirty_inode, so we have to call it before we

		 * take the ilock).

		 */

		if (!(file_out->f_mode & FMODE_NOCMTIME)) {

			ret = file_update_time(file_out);

			if (ret)

				goto out_unlock;

		}



		/*

		 * ...clear the security bits if the process is not being run

		 * by root.  This keeps people from modifying setuid and setgid

		 * binaries.

		 */

		ret = file_remove_privs(file_out);

		if (ret)

			goto out_unlock;

	}



	return 1;

	return 1;

out_unlock:

out_unlock:

	xfs_reflink_remap_unlock(file_in, file_out);

	xfs_reflink_remap_unlock(file_in, file_out);

CRA Git | Maintained and supported by SUSTech CRA and CCSE