From: Alexey Dobriyan <adobriyan@xxxxxxxxx> Subject: fs/proc/inode.c: use typeof_member() macro Don't repeat function signatures twice. This is a kind-of-precursor for "struct proc_ops". Note: typeof(pde->proc_fops->...) ...; can't be used because ->proc_fops is "const struct file_operations *". "const" prevents assignment down the code and it can't be deleted in the type system. Link: http://lkml.kernel.org/r/20190529191110.GB5703@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/proc/inode.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) --- a/fs/proc/inode.c~proc-use-typeof_member-macro +++ a/fs/proc/inode.c @@ -200,7 +200,8 @@ static loff_t proc_reg_llseek(struct fil struct proc_dir_entry *pde = PDE(file_inode(file)); loff_t rv = -EINVAL; if (use_pde(pde)) { - loff_t (*llseek)(struct file *, loff_t, int); + typeof_member(struct file_operations, llseek) llseek; + llseek = pde->proc_fops->llseek; if (!llseek) llseek = default_llseek; @@ -212,10 +213,11 @@ static loff_t proc_reg_llseek(struct fil static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { - ssize_t (*read)(struct file *, char __user *, size_t, loff_t *); struct proc_dir_entry *pde = PDE(file_inode(file)); ssize_t rv = -EIO; if (use_pde(pde)) { + typeof_member(struct file_operations, read) read; + read = pde->proc_fops->read; if (read) rv = read(file, buf, count, ppos); @@ -226,10 +228,11 @@ static ssize_t proc_reg_read(struct file static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { - ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *); struct proc_dir_entry *pde = PDE(file_inode(file)); ssize_t rv = -EIO; if (use_pde(pde)) { + typeof_member(struct file_operations, write) write; + write = pde->proc_fops->write; if (write) rv = write(file, buf, count, ppos); @@ -242,8 +245,9 @@ static __poll_t proc_reg_poll(struct fil { struct proc_dir_entry *pde = PDE(file_inode(file)); __poll_t rv = DEFAULT_POLLMASK; - __poll_t (*poll)(struct file *, struct poll_table_struct *); if (use_pde(pde)) { + typeof_member(struct file_operations, poll) poll; + poll = pde->proc_fops->poll; if (poll) rv = poll(file, pts); @@ -256,8 +260,9 @@ static long proc_reg_unlocked_ioctl(stru { struct proc_dir_entry *pde = PDE(file_inode(file)); long rv = -ENOTTY; - long (*ioctl)(struct file *, unsigned int, unsigned long); if (use_pde(pde)) { + typeof_member(struct file_operations, unlocked_ioctl) ioctl; + ioctl = pde->proc_fops->unlocked_ioctl; if (ioctl) rv = ioctl(file, cmd, arg); @@ -271,8 +276,9 @@ static long proc_reg_compat_ioctl(struct { struct proc_dir_entry *pde = PDE(file_inode(file)); long rv = -ENOTTY; - long (*compat_ioctl)(struct file *, unsigned int, unsigned long); if (use_pde(pde)) { + typeof_member(struct file_operations, compat_ioctl) compat_ioctl; + compat_ioctl = pde->proc_fops->compat_ioctl; if (compat_ioctl) rv = compat_ioctl(file, cmd, arg); @@ -286,8 +292,9 @@ static int proc_reg_mmap(struct file *fi { struct proc_dir_entry *pde = PDE(file_inode(file)); int rv = -EIO; - int (*mmap)(struct file *, struct vm_area_struct *); if (use_pde(pde)) { + typeof_member(struct file_operations, mmap) mmap; + mmap = pde->proc_fops->mmap; if (mmap) rv = mmap(file, vma); @@ -305,7 +312,7 @@ proc_reg_get_unmapped_area(struct file * unsigned long rv = -EIO; if (use_pde(pde)) { - typeof(proc_reg_get_unmapped_area) *get_area; + typeof_member(struct file_operations, get_unmapped_area) get_area; get_area = pde->proc_fops->get_unmapped_area; #ifdef CONFIG_MMU @@ -326,8 +333,8 @@ static int proc_reg_open(struct inode *i { struct proc_dir_entry *pde = PDE(inode); int rv = 0; - int (*open)(struct inode *, struct file *); - int (*release)(struct inode *, struct file *); + typeof_member(struct file_operations, open) open; + typeof_member(struct file_operations, release) release; struct pde_opener *pdeo; /* _
