From 4e3299eaddffd9d7d5b8bae28ad700bb775f02d0 Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Wed, 29 Jun 2022 15:06:59 +0200
Subject: [PATCH] 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>
---
fs/coredump.c | 4 ++--
fs/overlayfs/copy_up.c | 3 +--
fs/read_write.c | 11 +++--------
3 files changed, 6 insertions(+), 12 deletions(-)
diff --git a/fs/coredump.c b/fs/coredump.c
index ebc43f960b645..9f4aae2021093 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -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;
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 714ec569d25b3..022606c9703b9 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -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) {
diff --git a/fs/read_write.c b/fs/read_write.c
index b1b1cdfee9d39..d94b6dbba6f9c 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -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);
--
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