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proc: Delete create_proc_read_entry()
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Delete create_proc_read_entry() as it no longer has any users.

Also delete read_proc_t, write_proc_t, the read_proc member of the
proc_dir_entry struct and the support functions that use them.  This saves a
pointer for every PDE allocated.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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dhowells authored and Al Viro committed Apr 29, 2013
1 parent 526c597 commit 3cb5bf1
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Showing 4 changed files with 1 addition and 220 deletions.
168 changes: 1 addition & 167 deletions fs/proc/generic.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -36,141 +36,6 @@ static int proc_match(unsigned int len, const char *name, struct proc_dir_entry
return !memcmp(name, de->name, len);
}

/* buffer size is one page but our output routines use some slack for overruns */
#define PROC_BLOCK_SIZE (PAGE_SIZE - 1024)

ssize_t
__proc_file_read(struct file *file, char __user *buf, size_t nbytes,
loff_t *ppos)
{
struct inode * inode = file_inode(file);
char *page;
ssize_t retval=0;
int eof=0;
ssize_t n, count;
char *start;
struct proc_dir_entry * dp;
unsigned long long pos;

/*
* Gaah, please just use "seq_file" instead. The legacy /proc
* interfaces cut loff_t down to off_t for reads, and ignore
* the offset entirely for writes..
*/
pos = *ppos;
if (pos > MAX_NON_LFS)
return 0;
if (nbytes > MAX_NON_LFS - pos)
nbytes = MAX_NON_LFS - pos;

dp = PDE(inode);
if (!(page = (char*) __get_free_page(GFP_TEMPORARY)))
return -ENOMEM;

while ((nbytes > 0) && !eof) {
count = min_t(size_t, PROC_BLOCK_SIZE, nbytes);

start = NULL;
if (!dp->read_proc)
break;

/* How to be a proc read function
* ------------------------------
* Prototype:
* int f(char *buffer, char **start, off_t offset,
* int count, int *peof, void *dat)
*
* Assume that the buffer is "count" bytes in size.
*
* If you know you have supplied all the data you have, set
* *peof.
*
* You have three ways to return data:
*
* 0) Leave *start = NULL. (This is the default.) Put the
* data of the requested offset at that offset within the
* buffer. Return the number (n) of bytes there are from
* the beginning of the buffer up to the last byte of data.
* If the number of supplied bytes (= n - offset) is greater
* than zero and you didn't signal eof and the reader is
* prepared to take more data you will be called again with
* the requested offset advanced by the number of bytes
* absorbed. This interface is useful for files no larger
* than the buffer.
*
* 1) Set *start = an unsigned long value less than the buffer
* address but greater than zero. Put the data of the
* requested offset at the beginning of the buffer. Return
* the number of bytes of data placed there. If this number
* is greater than zero and you didn't signal eof and the
* reader is prepared to take more data you will be called
* again with the requested offset advanced by *start. This
* interface is useful when you have a large file consisting
* of a series of blocks which you want to count and return
* as wholes.
* (Hack by Paul.Russell@rustcorp.com.au)
*
* 2) Set *start = an address within the buffer. Put the data
* of the requested offset at *start. Return the number of
* bytes of data placed there. If this number is greater
* than zero and you didn't signal eof and the reader is
* prepared to take more data you will be called again with
* the requested offset advanced by the number of bytes
* absorbed.
*/
n = dp->read_proc(page, &start, *ppos, count, &eof, dp->data);

if (n == 0) /* end of file */
break;
if (n < 0) { /* error */
if (retval == 0)
retval = n;
break;
}

if (start == NULL) {
if (n > PAGE_SIZE) /* Apparent buffer overflow */
n = PAGE_SIZE;
n -= *ppos;
if (n <= 0)
break;
if (n > count)
n = count;
start = page + *ppos;
} else if (start < page) {
if (n > PAGE_SIZE) /* Apparent buffer overflow */
n = PAGE_SIZE;
if (n > count) {
/*
* Don't reduce n because doing so might
* cut off part of a data block.
*/
pr_warn("proc_file_read: count exceeded\n");
}
} else /* start >= page */ {
unsigned long startoff = (unsigned long)(start - page);
if (n > (PAGE_SIZE - startoff)) /* buffer overflow? */
n = PAGE_SIZE - startoff;
if (n > count)
n = count;
}

n -= copy_to_user(buf, start < page ? page : start, n);
if (n == 0) {
if (retval == 0)
retval = -EFAULT;
break;
}

*ppos += start < page ? (unsigned long)start : n;
nbytes -= n;
buf += n;
retval += n;
}
free_page((unsigned long) page);
return retval;
}

static int proc_notify_change(struct dentry *dentry, struct iattr *iattr)
{
struct inode *inode = dentry->d_inode;
Expand Down Expand Up @@ -476,8 +341,7 @@ static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp
} else if (S_ISLNK(dp->mode)) {
dp->proc_iops = &proc_link_inode_operations;
} else if (S_ISREG(dp->mode)) {
if (dp->proc_fops == NULL)
dp->proc_fops = &proc_file_operations;
BUG_ON(dp->proc_fops == NULL);
dp->proc_iops = &proc_file_inode_operations;
} else {
WARN_ON(1);
Expand Down Expand Up @@ -604,36 +468,6 @@ struct proc_dir_entry *proc_mkdir(const char *name,
}
EXPORT_SYMBOL(proc_mkdir);

struct proc_dir_entry *create_proc_read_entry(
const char *name, umode_t mode, struct proc_dir_entry *parent,
read_proc_t *read_proc, void *data)
{
struct proc_dir_entry *ent;

if ((mode & S_IFMT) == 0)
mode |= S_IFREG;

if (!S_ISREG(mode)) {
WARN_ON(1); /* use proc_mkdir(), damnit */
return NULL;
}

if ((mode & S_IALLUGO) == 0)
mode |= S_IRUGO;

ent = __proc_create(&parent, name, mode, 1);
if (ent) {
ent->read_proc = read_proc;
ent->data = data;
if (proc_register(parent, ent) < 0) {
kfree(ent);
ent = NULL;
}
}
return ent;
}
EXPORT_SYMBOL(create_proc_read_entry);

struct proc_dir_entry *proc_create_data(const char *name, umode_t mode,
struct proc_dir_entry *parent,
const struct file_operations *proc_fops,
Expand Down
35 changes: 0 additions & 35 deletions fs/proc/inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -183,41 +183,6 @@ void proc_entry_rundown(struct proc_dir_entry *de)
spin_unlock(&de->pde_unload_lock);
}

/* ->read_proc() users - legacy crap */
static ssize_t
proc_file_read(struct file *file, char __user *buf, size_t nbytes,
loff_t *ppos)
{
struct proc_dir_entry *pde = PDE(file_inode(file));
ssize_t rv = -EIO;
if (use_pde(pde)) {
rv = __proc_file_read(file, buf, nbytes, ppos);
unuse_pde(pde);
}
return rv;
}

static loff_t
proc_file_lseek(struct file *file, loff_t offset, int orig)
{
loff_t retval = -EINVAL;
switch (orig) {
case 1:
offset += file->f_pos;
/* fallthrough */
case 0:
if (offset < 0 || offset > MAX_NON_LFS)
break;
file->f_pos = retval = offset;
}
return retval;
}

const struct file_operations proc_file_operations = {
.llseek = proc_file_lseek,
.read = proc_file_read,
};

static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence)
{
struct proc_dir_entry *pde = PDE(file_inode(file));
Expand Down
2 changes: 0 additions & 2 deletions fs/proc/internal.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -157,8 +157,6 @@ struct pde_opener {
struct completion *c;
};

ssize_t __proc_file_read(struct file *, char __user *, size_t, loff_t *);
extern const struct file_operations proc_file_operations;
void proc_entry_rundown(struct proc_dir_entry *);

extern spinlock_t proc_subdir_lock;
Expand Down
16 changes: 0 additions & 16 deletions include/linux/proc_fs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -47,11 +47,6 @@ enum {
* non-directory entries).
*/

typedef int (read_proc_t)(char *page, char **start, off_t off,
int count, int *eof, void *data);
typedef int (write_proc_t)(struct file *file, const char __user *buffer,
unsigned long count, void *data);

struct proc_dir_entry {
unsigned int low_ino;
umode_t mode;
Expand All @@ -63,7 +58,6 @@ struct proc_dir_entry {
const struct file_operations *proc_fops;
struct proc_dir_entry *next, *parent, *subdir;
void *data;
read_proc_t *read_proc;
atomic_t count; /* use count */
atomic_t in_use; /* number of callers into module in progress; */
/* negative -> it's going away RSN */
Expand Down Expand Up @@ -154,11 +148,6 @@ static inline struct proc_dir_entry *proc_create(const char *name, umode_t mode,
{
return proc_create_data(name, mode, parent, proc_fops, NULL);
}

extern __deprecated
struct proc_dir_entry *create_proc_read_entry(const char *name,
umode_t mode, struct proc_dir_entry *base,
read_proc_t *read_proc, void *data);

extern struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name,
struct proc_dir_entry *parent);
Expand Down Expand Up @@ -192,11 +181,6 @@ static inline struct proc_dir_entry *proc_mkdir(const char *name,
static inline struct proc_dir_entry *proc_mkdir_mode(const char *name,
umode_t mode, struct proc_dir_entry *parent) { return NULL; }

static inline __deprecated
struct proc_dir_entry *create_proc_read_entry(const char *name,
umode_t mode, struct proc_dir_entry *base,
read_proc_t *read_proc, void * data) { return NULL; }

struct tty_driver;
static inline void proc_tty_register_driver(struct tty_driver *driver) {};
static inline void proc_tty_unregister_driver(struct tty_driver *driver) {};
Expand Down

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