proc: decouple proc from VFS with "struct proc_ops"

Currently core /proc code uses "struct file_operations" for custom hooks,
however, VFS doesn't directly call them.  Every time VFS expands
file_operations hook set, /proc code bloats for no reason.

Introduce "struct proc_ops" which contains only those hooks which /proc
allows to call into (open, release, read, write, ioctl, mmap, poll).  It
doesn't contain module pointer as well.

Save ~184 bytes per usage:

	add/remove: 26/26 grow/shrink: 1/4 up/down: 1922/-6674 (-4752)
	Function                                     old     new   delta
	sysvipc_proc_ops                               -      72     +72
				...
	config_gz_proc_ops                             -      72     +72
	proc_get_inode                               289     339     +50
	proc_reg_get_unmapped_area                   110     107      -3
	close_pdeo                                   227     224      -3
	proc_reg_open                                289     284      -5
	proc_create_data                              60      53      -7
	rt_cpu_seq_fops                              256       -    -256
				...
	default_affinity_proc_fops                   256       -    -256
	Total: Before=5430095, After=5425343, chg -0.09%

Link: http://lkml.kernel.org/r/20191225172228.GA13378@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 074e958..3faed94 100644 (file)
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -473,7 +473,7 @@ struct proc_dir_entry *proc_mkdir_data(const char *name, umode_t mode,
        ent = __proc_create(&parent, name, S_IFDIR | mode, 2);
        if (ent) {
                ent->data = data;
-               ent->proc_fops = &proc_dir_operations;
+               ent->proc_dir_ops = &proc_dir_operations;
                ent->proc_iops = &proc_dir_inode_operations;
                ent = proc_register(parent, ent);
        }
@@ -503,7 +503,7 @@ struct proc_dir_entry *proc_create_mount_point(const char *name)
        ent = __proc_create(&parent, name, mode, 2);
        if (ent) {
                ent->data = NULL;
-               ent->proc_fops = NULL;
+               ent->proc_dir_ops = NULL;
                ent->proc_iops = NULL;
                ent = proc_register(parent, ent);
        }
@@ -533,25 +533,23 @@ struct proc_dir_entry *proc_create_reg(const char *name, umode_t mode,
 
 struct proc_dir_entry *proc_create_data(const char *name, umode_t mode,
                struct proc_dir_entry *parent,
-               const struct file_operations *proc_fops, void *data)
+               const struct proc_ops *proc_ops, void *data)
 {
        struct proc_dir_entry *p;
 
-       BUG_ON(proc_fops == NULL);
-
        p = proc_create_reg(name, mode, &parent, data);
        if (!p)
                return NULL;
-       p->proc_fops = proc_fops;
+       p->proc_ops = proc_ops;
        return proc_register(parent, p);
 }
 EXPORT_SYMBOL(proc_create_data);
  
 struct proc_dir_entry *proc_create(const char *name, umode_t mode,
                                   struct proc_dir_entry *parent,
-                                  const struct file_operations *proc_fops)
+                                  const struct proc_ops *proc_ops)
 {
-       return proc_create_data(name, mode, parent, proc_fops, NULL);
+       return proc_create_data(name, mode, parent, proc_ops, NULL);
 }
 EXPORT_SYMBOL(proc_create);
 
@@ -573,11 +571,11 @@ static int proc_seq_release(struct inode *inode, struct file *file)
        return seq_release(inode, file);
 }
 
-static const struct file_operations proc_seq_fops = {
-       .open           = proc_seq_open,
-       .read           = seq_read,
-       .llseek         = seq_lseek,
-       .release        = proc_seq_release,
+static const struct proc_ops proc_seq_ops = {
+       .proc_open      = proc_seq_open,
+       .proc_read      = seq_read,
+       .proc_lseek     = seq_lseek,
+       .proc_release   = proc_seq_release,
 };
 
 struct proc_dir_entry *proc_create_seq_private(const char *name, umode_t mode,
@@ -589,7 +587,7 @@ struct proc_dir_entry *proc_create_seq_private(const char *name, umode_t mode,
        p = proc_create_reg(name, mode, &parent, data);
        if (!p)
                return NULL;
-       p->proc_fops = &proc_seq_fops;
+       p->proc_ops = &proc_seq_ops;
        p->seq_ops = ops;
        p->state_size = state_size;
        return proc_register(parent, p);
@@ -603,11 +601,11 @@ static int proc_single_open(struct inode *inode, struct file *file)
        return single_open(file, de->single_show, de->data);
 }
 
-static const struct file_operations proc_single_fops = {
-       .open           = proc_single_open,
-       .read           = seq_read,
-       .llseek         = seq_lseek,
-       .release        = single_release,
+static const struct proc_ops proc_single_ops = {
+       .proc_open      = proc_single_open,
+       .proc_read      = seq_read,
+       .proc_lseek     = seq_lseek,
+       .proc_release   = single_release,
 };
 
 struct proc_dir_entry *proc_create_single_data(const char *name, umode_t mode,
@@ -619,7 +617,7 @@ struct proc_dir_entry *proc_create_single_data(const char *name, umode_t mode,
        p = proc_create_reg(name, mode, &parent, data);
        if (!p)
                return NULL;
-       p->proc_fops = &proc_single_fops;
+       p->proc_ops = &proc_single_ops;
        p->single_show = show;
        return proc_register(parent, p);
 }

diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index dbe43a5..6da1831 100644 (file)
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -163,7 +163,7 @@ static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo)
                pdeo->closing = true;
                spin_unlock(&pde->pde_unload_lock);
                file = pdeo->file;
-               pde->proc_fops->release(file_inode(file), file);
+               pde->proc_ops->proc_release(file_inode(file), file);
                spin_lock(&pde->pde_unload_lock);
                /* After ->release. */
                list_del(&pdeo->lh);
@@ -200,12 +200,12 @@ static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence)
        struct proc_dir_entry *pde = PDE(file_inode(file));
        loff_t rv = -EINVAL;
        if (use_pde(pde)) {
-               typeof_member(struct file_operations, llseek) llseek;
+               typeof_member(struct proc_ops, proc_lseek) lseek;
 
-               llseek = pde->proc_fops->llseek;
-               if (!llseek)
-                       llseek = default_llseek;
-               rv = llseek(file, offset, whence);
+               lseek = pde->proc_ops->proc_lseek;
+               if (!lseek)
+                       lseek = default_llseek;
+               rv = lseek(file, offset, whence);
                unuse_pde(pde);
        }
        return rv;
@@ -216,9 +216,9 @@ static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count,
        struct proc_dir_entry *pde = PDE(file_inode(file));
        ssize_t rv = -EIO;
        if (use_pde(pde)) {
-               typeof_member(struct file_operations, read) read;
+               typeof_member(struct proc_ops, proc_read) read;
 
-               read = pde->proc_fops->read;
+               read = pde->proc_ops->proc_read;
                if (read)
                        rv = read(file, buf, count, ppos);
                unuse_pde(pde);
@@ -231,9 +231,9 @@ static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_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;
+               typeof_member(struct proc_ops, proc_write) write;
 
-               write = pde->proc_fops->write;
+               write = pde->proc_ops->proc_write;
                if (write)
                        rv = write(file, buf, count, ppos);
                unuse_pde(pde);
@@ -246,9 +246,9 @@ static __poll_t proc_reg_poll(struct file *file, struct poll_table_struct *pts)
        struct proc_dir_entry *pde = PDE(file_inode(file));
        __poll_t rv = DEFAULT_POLLMASK;
        if (use_pde(pde)) {
-               typeof_member(struct file_operations, poll) poll;
+               typeof_member(struct proc_ops, proc_poll) poll;
 
-               poll = pde->proc_fops->poll;
+               poll = pde->proc_ops->proc_poll;
                if (poll)
                        rv = poll(file, pts);
                unuse_pde(pde);
@@ -261,9 +261,9 @@ static long proc_reg_unlocked_ioctl(struct file *file, unsigned int cmd, unsigne
        struct proc_dir_entry *pde = PDE(file_inode(file));
        long rv = -ENOTTY;
        if (use_pde(pde)) {
-               typeof_member(struct file_operations, unlocked_ioctl) ioctl;
+               typeof_member(struct proc_ops, proc_ioctl) ioctl;
 
-               ioctl = pde->proc_fops->unlocked_ioctl;
+               ioctl = pde->proc_ops->proc_ioctl;
                if (ioctl)
                        rv = ioctl(file, cmd, arg);
                unuse_pde(pde);
@@ -277,9 +277,9 @@ static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned
        struct proc_dir_entry *pde = PDE(file_inode(file));
        long rv = -ENOTTY;
        if (use_pde(pde)) {
-               typeof_member(struct file_operations, compat_ioctl) compat_ioctl;
+               typeof_member(struct proc_ops, proc_compat_ioctl) compat_ioctl;
 
-               compat_ioctl = pde->proc_fops->compat_ioctl;
+               compat_ioctl = pde->proc_ops->proc_compat_ioctl;
                if (compat_ioctl)
                        rv = compat_ioctl(file, cmd, arg);
                unuse_pde(pde);
@@ -293,9 +293,9 @@ static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma)
        struct proc_dir_entry *pde = PDE(file_inode(file));
        int rv = -EIO;
        if (use_pde(pde)) {
-               typeof_member(struct file_operations, mmap) mmap;
+               typeof_member(struct proc_ops, proc_mmap) mmap;
 
-               mmap = pde->proc_fops->mmap;
+               mmap = pde->proc_ops->proc_mmap;
                if (mmap)
                        rv = mmap(file, vma);
                unuse_pde(pde);
@@ -312,9 +312,9 @@ proc_reg_get_unmapped_area(struct file *file, unsigned long orig_addr,
        unsigned long rv = -EIO;
 
        if (use_pde(pde)) {
-               typeof_member(struct file_operations, get_unmapped_area) get_area;
+               typeof_member(struct proc_ops, proc_get_unmapped_area) get_area;
 
-               get_area = pde->proc_fops->get_unmapped_area;
+               get_area = pde->proc_ops->proc_get_unmapped_area;
 #ifdef CONFIG_MMU
                if (!get_area)
                        get_area = current->mm->get_unmapped_area;
@@ -333,8 +333,8 @@ static int proc_reg_open(struct inode *inode, struct file *file)
 {
        struct proc_dir_entry *pde = PDE(inode);
        int rv = 0;
-       typeof_member(struct file_operations, open) open;
-       typeof_member(struct file_operations, release) release;
+       typeof_member(struct proc_ops, proc_open) open;
+       typeof_member(struct proc_ops, proc_release) release;
        struct pde_opener *pdeo;
 
        /*
@@ -351,7 +351,7 @@ static int proc_reg_open(struct inode *inode, struct file *file)
        if (!use_pde(pde))
                return -ENOENT;
 
-       release = pde->proc_fops->release;
+       release = pde->proc_ops->proc_release;
        if (release) {
                pdeo = kmem_cache_alloc(pde_opener_cache, GFP_KERNEL);
                if (!pdeo) {
@@ -360,7 +360,7 @@ static int proc_reg_open(struct inode *inode, struct file *file)
                }
        }
 
-       open = pde->proc_fops->open;
+       open = pde->proc_ops->proc_open;
        if (open)
                rv = open(inode, file);
 
@@ -468,21 +468,23 @@ struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de)
                        inode->i_size = de->size;
                if (de->nlink)
                        set_nlink(inode, de->nlink);
-               WARN_ON(!de->proc_iops);
-               inode->i_op = de->proc_iops;
-               if (de->proc_fops) {
-                       if (S_ISREG(inode->i_mode)) {
+
+               if (S_ISREG(inode->i_mode)) {
+                       inode->i_op = de->proc_iops;
+                       inode->i_fop = &proc_reg_file_ops;
 #ifdef CONFIG_COMPAT
-                               if (!de->proc_fops->compat_ioctl)
-                                       inode->i_fop =
-                                               &proc_reg_file_ops_no_compat;
-                               else
-#endif
-                                       inode->i_fop = &proc_reg_file_ops;
-                       } else {
-                               inode->i_fop = de->proc_fops;
+                       if (!de->proc_ops->proc_compat_ioctl) {
+                               inode->i_fop = &proc_reg_file_ops_no_compat;
                        }
-               }
+#endif
+               } else if (S_ISDIR(inode->i_mode)) {
+                       inode->i_op = de->proc_iops;
+                       inode->i_fop = de->proc_dir_ops;
+               } else if (S_ISLNK(inode->i_mode)) {
+                       inode->i_op = de->proc_iops;
+                       inode->i_fop = NULL;
+               } else
+                       BUG();
        } else
               pde_put(de);
        return inode;

diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 0f3b557..4158727 100644 (file)
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -39,7 +39,10 @@ struct proc_dir_entry {
        spinlock_t pde_unload_lock;
        struct completion *pde_unload_completion;
        const struct inode_operations *proc_iops;
-       const struct file_operations *proc_fops;
+       union {
+               const struct proc_ops *proc_ops;
+               const struct file_operations *proc_dir_ops;
+       };
        const struct dentry_operations *proc_dops;
        union {
                const struct seq_operations *seq_ops;

diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c
index 76ae278..4888c52 100644 (file)
--- a/fs/proc/proc_net.c
+++ b/fs/proc/proc_net.c
@@ -90,12 +90,12 @@ static int seq_release_net(struct inode *ino, struct file *f)
        return 0;
 }
 
-static const struct file_operations proc_net_seq_fops = {
-       .open           = seq_open_net,
-       .read           = seq_read,
-       .write          = proc_simple_write,
-       .llseek         = seq_lseek,
-       .release        = seq_release_net,
+static const struct proc_ops proc_net_seq_ops = {
+       .proc_open      = seq_open_net,
+       .proc_read      = seq_read,
+       .proc_write     = proc_simple_write,
+       .proc_lseek     = seq_lseek,
+       .proc_release   = seq_release_net,
 };
 
 struct proc_dir_entry *proc_create_net_data(const char *name, umode_t mode,
@@ -108,7 +108,7 @@ struct proc_dir_entry *proc_create_net_data(const char *name, umode_t mode,
        if (!p)
                return NULL;
        pde_force_lookup(p);
-       p->proc_fops = &proc_net_seq_fops;
+       p->proc_ops = &proc_net_seq_ops;
        p->seq_ops = ops;
        p->state_size = state_size;
        return proc_register(parent, p);
@@ -152,7 +152,7 @@ struct proc_dir_entry *proc_create_net_data_write(const char *name, umode_t mode
        if (!p)
                return NULL;
        pde_force_lookup(p);
-       p->proc_fops = &proc_net_seq_fops;
+       p->proc_ops = &proc_net_seq_ops;
        p->seq_ops = ops;
        p->state_size = state_size;
        p->write = write;
@@ -183,12 +183,12 @@ static int single_release_net(struct inode *ino, struct file *f)
        return single_release(ino, f);
 }
 
-static const struct file_operations proc_net_single_fops = {
-       .open           = single_open_net,
-       .read           = seq_read,
-       .write          = proc_simple_write,
-       .llseek         = seq_lseek,
-       .release        = single_release_net,
+static const struct proc_ops proc_net_single_ops = {
+       .proc_open      = single_open_net,
+       .proc_read      = seq_read,
+       .proc_write     = proc_simple_write,
+       .proc_lseek     = seq_lseek,
+       .proc_release   = single_release_net,
 };
 
 struct proc_dir_entry *proc_create_net_single(const char *name, umode_t mode,
@@ -201,7 +201,7 @@ struct proc_dir_entry *proc_create_net_single(const char *name, umode_t mode,
        if (!p)
                return NULL;
        pde_force_lookup(p);
-       p->proc_fops = &proc_net_single_fops;
+       p->proc_ops = &proc_net_single_ops;
        p->single_show = show;
        return proc_register(parent, p);
 }
@@ -244,7 +244,7 @@ struct proc_dir_entry *proc_create_net_single_write(const char *name, umode_t mo
        if (!p)
                return NULL;
        pde_force_lookup(p);
-       p->proc_fops = &proc_net_single_fops;
+       p->proc_ops = &proc_net_single_ops;
        p->single_show = show;
        p->write = write;
        return proc_register(parent, p);

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index d80989b..c75bb46 100644 (file)
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -1720,7 +1720,7 @@ int __init proc_sys_init(void)
 
        proc_sys_root = proc_mkdir("sys", NULL);
        proc_sys_root->proc_iops = &proc_sys_dir_operations;
-       proc_sys_root->proc_fops = &proc_sys_dir_file_operations;
+       proc_sys_root->proc_dir_ops = &proc_sys_dir_file_operations;
        proc_sys_root->nlink = 0;
 
        return sysctl_init();

diff --git a/fs/proc/root.c b/fs/proc/root.c
index 0b7c8df..72c07a3 100644 (file)
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -292,7 +292,7 @@ struct proc_dir_entry proc_root = {
        .nlink          = 2, 
        .refcnt         = REFCOUNT_INIT(1),
        .proc_iops      = &proc_root_inode_operations, 
-       .proc_fops      = &proc_root_operations,
+       .proc_dir_ops   = &proc_root_operations,
        .parent         = &proc_root,
        .subdir         = RB_ROOT,
        .name           = "/proc",

diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index 0640be5..3dfa926 100644 (file)
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -12,6 +12,21 @@ struct proc_dir_entry;
 struct seq_file;
 struct seq_operations;
 
+struct proc_ops {
+       int     (*proc_open)(struct inode *, struct file *);
+       ssize_t (*proc_read)(struct file *, char __user *, size_t, loff_t *);
+       ssize_t (*proc_write)(struct file *, const char __user *, size_t, loff_t *);
+       loff_t  (*proc_lseek)(struct file *, loff_t, int);
+       int     (*proc_release)(struct inode *, struct file *);
+       __poll_t (*proc_poll)(struct file *, struct poll_table_struct *);
+       long    (*proc_ioctl)(struct file *, unsigned int, unsigned long);
+#ifdef CONFIG_COMPAT
+       long    (*proc_compat_ioctl)(struct file *, unsigned int, unsigned long);
+#endif
+       int     (*proc_mmap)(struct file *, struct vm_area_struct *);
+       unsigned long (*proc_get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
+};
+
 #ifdef CONFIG_PROC_FS
 
 typedef int (*proc_write_t)(struct file *, char *, size_t);
@@ -43,10 +58,10 @@ struct proc_dir_entry *proc_create_single_data(const char *name, umode_t mode,
  
 extern struct proc_dir_entry *proc_create_data(const char *, umode_t,
                                               struct proc_dir_entry *,
-                                              const struct file_operations *,
+                                              const struct proc_ops *,
                                               void *);
 
-struct proc_dir_entry *proc_create(const char *name, umode_t mode, struct proc_dir_entry *parent, const struct file_operations *proc_fops);
+struct proc_dir_entry *proc_create(const char *name, umode_t mode, struct proc_dir_entry *parent, const struct proc_ops *proc_ops);
 extern void proc_set_size(struct proc_dir_entry *, loff_t);
 extern void proc_set_user(struct proc_dir_entry *, kuid_t, kgid_t);
 extern void *PDE_DATA(const struct inode *);
@@ -108,8 +123,8 @@ static inline struct proc_dir_entry *proc_mkdir_mode(const char *name,
 #define proc_create_seq(name, mode, parent, ops) ({NULL;})
 #define proc_create_single(name, mode, parent, show) ({NULL;})
 #define proc_create_single_data(name, mode, parent, show, data) ({NULL;})
-#define proc_create(name, mode, parent, proc_fops) ({NULL;})
-#define proc_create_data(name, mode, parent, proc_fops, data) ({NULL;})
+#define proc_create(name, mode, parent, proc_ops) ({NULL;})
+#define proc_create_data(name, mode, parent, proc_ops, data) ({NULL;})
 
 static inline void proc_set_size(struct proc_dir_entry *de, loff_t size) {}
 static inline void proc_set_user(struct proc_dir_entry *de, kuid_t uid, kgid_t gid) {}