[PATCH 01/11] mem: remove duplicate ops for /dev/zero and /dev/null

Christoph Hellwig
2020-08-17T07:32:36Z

There is no good reason to implement both the traditional ->read and
->write as well as the iter based ops. So implement just the iter
based ones.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/char/mem.c | 16 ----------------
1 file changed, 16 deletions(-)

diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 687d4af6945d36..14851f36787372 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -670,18 +670,6 @@ static ssize_t write_port(struct file *file, const char __user *buf,
return tmp-buf;
}

-static ssize_t read_null(struct file *file, char __user *buf,
- size_t count, loff_t *ppos)
-{
- return 0;
-}
-
-static ssize_t write_null(struct file *file, const char __user *buf,
- size_t count, loff_t *ppos)
-{
- return count;
-}
-
static ssize_t read_iter_null(struct kiocb *iocb, struct iov_iter *to)
{
return 0;
@@ -872,7 +860,6 @@ static int open_port(struct inode *inode, struct file *filp)

#define zero_lseek null_lseek
#define full_lseek null_lseek
-#define write_zero write_null
#define write_iter_zero write_iter_null
#define open_mem open_port
#define open_kmem open_mem
@@ -903,8 +890,6 @@ static const struct file_operations __maybe_unused kmem_fops = {

static const struct file_operations null_fops = {
.llseek = null_lseek,
- .read = read_null,
- .write = write_null,
.read_iter = read_iter_null,
.write_iter = write_iter_null,
.splice_write = splice_write_null,
@@ -919,7 +904,6 @@ static const struct file_operations __maybe_unused port_fops = {

static const struct file_operations zero_fops = {
.llseek = zero_lseek,
- .write = write_zero,
.read_iter = read_iter_zero,
.write_iter = write_iter_zero,
.mmap = mmap_zero,
--
2.28.0