Commit 4e3299ea authored Jun 29, 2022 by Jason A. Donenfeld Committed by Al Viro Jul 16, 2022

fs: do not compare against ->llseek



Now vfs_llseek() can simply check for FMODE_LSEEK; if it's set,
we know that ->llseek() won't be NULL and if it's not we should
just fail with -ESPIPE.

A couple of other places where we used to check for special
values of ->llseek() (somewhat inconsistently) switched to
checking FMODE_LSEEK.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

parent e7478158

fs/coredump.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -816,9 +816,9 @@ static int __dump_skip(struct coredump_params *cprm, size_t nr)
		{
		static char zeroes[PAGE_SIZE];
		struct file *file = cprm->file;
		if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
		if (file->f_mode & FMODE_LSEEK) {
		if (dump_interrupted() \|\|
		file->f_op->llseek(file, nr, SEEK_CUR) < 0)
		vfs_llseek(file, nr, SEEK_CUR) < 0)
		return 0;
		cprm->pos += nr;
		return 1;

fs/overlayfs/copy_up.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -226,8 +226,7 @@ static int ovl_copy_up_data(struct ovl_fs ofs, struct path old,
		/* Couldn't clone, so now we try to copy the data */

		/* Check if lower fs supports seek operation */
		if (old_file->f_mode & FMODE_LSEEK &&
		old_file->f_op->llseek)
		if (old_file->f_mode & FMODE_LSEEK)
		skip_hole = true;

		while (len) {

fs/read_write.c

+3 −8

Original line number	Diff line number	Diff line
		@@ -290,14 +290,9 @@ EXPORT_SYMBOL(default_llseek);

		loff_t vfs_llseek(struct file *file, loff_t offset, int whence)
		{
		loff_t (fn)(struct file , loff_t, int);

		fn = no_llseek;
		if (file->f_mode & FMODE_LSEEK) {
		if (file->f_op->llseek)
		fn = file->f_op->llseek;
		}
		return fn(file, offset, whence);
		if (!(file->f_mode & FMODE_LSEEK))
		return -ESPIPE;
		return file->f_op->llseek(file, offset, whence);
		}
		EXPORT_SYMBOL(vfs_llseek);