[PATCH 2/2] fs: remove fs.f_write_hint

Christoph Hellwig
2022-03-08T06:05:39Z

The value is now completely unused except for reporting it back through
the F_GET_FILE_RW_HINT ioctl, so remove the value and the two ioctls
for it.

Trying to use the F_SET_FILE_RW_HINT and F_GET_FILE_RW_HINT fcntls will
now return EINVAL, just like it would on a kernel that never supported
this functionality in the first place.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/fcntl.c | 18 ------------------
fs/open.c | 1 -
include/linux/fs.h | 9 ---------
3 files changed, 28 deletions(-)

diff --git a/fs/fcntl.c b/fs/fcntl.c
index 9c6c6a3e2de51..f15d885b97961 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -291,22 +291,6 @@ static long fcntl_rw_hint(struct file *file, unsigned int cmd,
u64 h;

switch (cmd) {
- case F_GET_FILE_RW_HINT:
- h = file_write_hint(file);
- if (copy_to_user(argp, &h, sizeof(*argp)))
- return -EFAULT;
- return 0;
- case F_SET_FILE_RW_HINT:
- if (copy_from_user(&h, argp, sizeof(h)))
- return -EFAULT;
- hint = (enum rw_hint) h;
- if (!rw_hint_valid(hint))
- return -EINVAL;
-
- spin_lock(&file->f_lock);
- file->f_write_hint = hint;
- spin_unlock(&file->f_lock);
- return 0;
case F_GET_RW_HINT:
h = inode->i_write_hint;
if (copy_to_user(argp, &h, sizeof(*argp)))
@@ -431,8 +415,6 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
break;
case F_GET_RW_HINT:
case F_SET_RW_HINT:
- case F_GET_FILE_RW_HINT:
- case F_SET_FILE_RW_HINT:
err = fcntl_rw_hint(filp, cmd, arg);
break;
default:
diff --git a/fs/open.c b/fs/open.c
index 9ff2f621b760b..1315253e02473 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -835,7 +835,6 @@ static int do_dentry_open(struct file *f,
likely(f->f_op->write || f->f_op->write_iter))
f->f_mode |= FMODE_CAN_WRITE;

- f->f_write_hint = WRITE_LIFE_NOT_SET;
f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);

file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index d5658ac5d8c65..a1fc3b41cd82f 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -966,7 +966,6 @@ struct file {
* Must not be taken from IRQ context.
*/
spinlock_t f_lock;
- enum rw_hint f_write_hint;
atomic_long_t f_count;
unsigned int f_flags;
fmode_t f_mode;
@@ -2214,14 +2213,6 @@ static inline bool HAS_UNMAPPED_ID(struct user_namespace *mnt_userns,
!gid_valid(i_gid_into_mnt(mnt_userns, inode));
}

-static inline enum rw_hint file_write_hint(struct file *file)
-{
- if (file->f_write_hint != WRITE_LIFE_NOT_SET)
- return file->f_write_hint;
-
- return file_inode(file)->i_write_hint;
-}
-
static inline int iocb_flags(struct file *file);

static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
--
2.30.2