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proc: decouple proc from VFS with "struct proc_ops"
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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 <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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@torvalds
Alexey Dobriyan authored and torvalds committed Feb 4, 2020
1 parent 0d6e24d commit d56c0d4
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Showing 7 changed files with 98 additions and 80 deletions.
38 changes: 18 additions & 20 deletions fs/proc/generic.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
}
Expand Down Expand Up @@ -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);
}
Expand Down Expand Up @@ -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);

Expand All @@ -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,
Expand All @@ -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);
Expand All @@ -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,
Expand All @@ -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);
}
Expand Down
76 changes: 39 additions & 37 deletions fs/proc/inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down Expand Up @@ -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;
Expand All @@ -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);
Expand All @@ -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);
Expand All @@ -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);
Expand All @@ -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);
Expand All @@ -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);
Expand All @@ -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);
Expand All @@ -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;
Expand All @@ -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;

/*
Expand All @@ -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) {
Expand All @@ -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);

Expand Down Expand Up @@ -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;
Expand Down
5 changes: 4 additions & 1 deletion fs/proc/internal.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down
32 changes: 16 additions & 16 deletions fs/proc/proc_net.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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,
Expand All @@ -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);
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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,
Expand All @@ -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);
}
Expand Down Expand Up @@ -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);
Expand Down
2 changes: 1 addition & 1 deletion fs/proc/proc_sysctl.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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();
Expand Down
2 changes: 1 addition & 1 deletion fs/proc/root.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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",
Expand Down
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