Commit e38f7f53 authored by Amir Goldstein's avatar Amir Goldstein Committed by Darrick J. Wong
Browse files

vfs: introduce file_modified() helper 



The combination of file_remove_privs() and file_update_mtime() is
quite common in filesystem ->write_iter() methods.

Modelled after the helper file_accessed(), introduce file_modified()
and use it from generic_remap_file_range_prep().

Note that the order of calling file_remove_privs() before
file_update_mtime() in the helper was matched to the more common order by
filesystems and not the current order in generic_remap_file_range_prep().

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 96e6e8f4

fs/inode.c

+20 −0
Original line number Diff line number Diff line
@@ -1899,6 +1899,26 @@ int file_update_time(struct file *file) 
}

EXPORT_SYMBOL(file_update_time);



/* Caller must hold the file's inode lock */

int file_modified(struct file *file)

{

	int err;



	/*

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

	 * This keeps people from modifying setuid and setgid binaries.

	 */

	err = file_remove_privs(file);

	if (err)

		return err;



	if (unlikely(file->f_mode & FMODE_NOCMTIME))

		return 0;



	return file_update_time(file);

}

EXPORT_SYMBOL(file_modified);



int inode_needs_sync(struct inode *inode)

{

	if (IS_SYNC(inode))

fs/read_write.c

+3 −18
Original line number Diff line number Diff line
@@ -1980,26 +1980,11 @@ int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, 
		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;

		}

	if (!(remap_flags & REMAP_FILE_DEDUP))

		ret = file_modified(file_out);



		/*

		 * 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 0;

}

EXPORT_SYMBOL(generic_remap_file_range_prep);



loff_t do_clone_file_range(struct file *file_in, loff_t pos_in,

include/linux/fs.h

+2 −0
Original line number Diff line number Diff line
@@ -2177,6 +2177,8 @@ static inline void file_accessed(struct file *file) 
		touch_atime(&file->f_path);

}



extern int file_modified(struct file *file);



int sync_inode(struct inode *inode, struct writeback_control *wbc);

int sync_inode_metadata(struct inode *inode, int wait);

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