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>
This commit is contained in:
Jason A. Donenfeld 2022-06-29 15:06:59 +02:00 committed by Al Viro
parent e7478158e1
commit 4e3299eadd
3 changed files with 6 additions and 12 deletions

View File

@ -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;

View File

@ -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) {

View File

@ -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);