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pipe: fold file_operations instances in one 

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
hifive-unleashed-5.1
Al Viro 2013-03-12 09:58:10 -04:00
parent f776c73888
commit 599a0ac14e
4 changed files with 38 additions and 195 deletions
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2
fs/inode.c
View File

@ -1803,7 +1803,7 @@ void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev)
inode->i_fop = &def_blk_fops;
inode->i_rdev = rdev;
} else if (S_ISFIFO(mode))
inode->i_fop = &def_fifo_fops;
inode->i_fop = &pipefifo_fops;
else if (S_ISSOCK(mode))
inode->i_fop = &bad_sock_fops;
else

5
fs/internal.h
View File

@ -130,3 +130,8 @@ extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
* read_write.c
*/
extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);
/*
* pipe.c
*/
extern const struct file_operations pipefifo_fops;

221
fs/pipe.c
View File

@ -25,6 +25,8 @@
#include <asm/uaccess.h>
#include <asm/ioctls.h>
#include "internal.h"
/*
* The max size that a non-root user is allowed to grow the pipe. Can
* be set by root in /proc/sys/fs/pipe-max-size
@ -662,19 +664,6 @@ out:
return ret;
}
static ssize_t
bad_pipe_r(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
{
return -EBADF;
}
static ssize_t
bad_pipe_w(struct file *filp, const char __user *buf, size_t count,
loff_t *ppos)
{
return -EBADF;
}
static long pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
@ -734,14 +723,16 @@ pipe_poll(struct file *filp, poll_table *wait)
}
static int
pipe_release(struct inode *inode, int decr, int decw)
pipe_release(struct inode *inode, struct file *file)
{
struct pipe_inode_info *pipe;
mutex_lock(&inode->i_mutex);
pipe = inode->i_pipe;
pipe->readers -= decr;
pipe->writers -= decw;
if (file->f_mode & FMODE_READ)
pipe->readers--;
if (file->f_mode & FMODE_WRITE)
pipe->writers--;
if (!pipe->readers && !pipe->writers) {
free_pipe_info(inode);
@ -756,174 +747,25 @@ pipe_release(struct inode *inode, int decr, int decw)
}
static int
pipe_read_fasync(int fd, struct file *filp, int on)
{
struct inode *inode = file_inode(filp);
int retval;
mutex_lock(&inode->i_mutex);
retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_readers);
mutex_unlock(&inode->i_mutex);
return retval;
}
static int
pipe_write_fasync(int fd, struct file *filp, int on)
{
struct inode *inode = file_inode(filp);
int retval;
mutex_lock(&inode->i_mutex);
retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_writers);
mutex_unlock(&inode->i_mutex);
return retval;
}
static int
pipe_rdwr_fasync(int fd, struct file *filp, int on)
pipe_fasync(int fd, struct file *filp, int on)
{
struct inode *inode = file_inode(filp);
struct pipe_inode_info *pipe = inode->i_pipe;
int retval;
int retval = 0;
mutex_lock(&inode->i_mutex);
retval = fasync_helper(fd, filp, on, &pipe->fasync_readers);
if (retval >= 0) {
if (filp->f_mode & FMODE_READ)
retval = fasync_helper(fd, filp, on, &pipe->fasync_readers);
if ((filp->f_mode & FMODE_WRITE) && retval >= 0) {
retval = fasync_helper(fd, filp, on, &pipe->fasync_writers);
if (retval < 0) /* this can happen only if on == T */
if (retval < 0 && (filp->f_mode & FMODE_READ))
/* this can happen only if on == T */
fasync_helper(-1, filp, 0, &pipe->fasync_readers);
}
mutex_unlock(&inode->i_mutex);
return retval;
}
static int
pipe_read_release(struct inode *inode, struct file *filp)
{
return pipe_release(inode, 1, 0);
}
static int
pipe_write_release(struct inode *inode, struct file *filp)
{
return pipe_release(inode, 0, 1);
}
static int
pipe_rdwr_release(struct inode *inode, struct file *filp)
{
int decr, decw;
decr = (filp->f_mode & FMODE_READ) != 0;
decw = (filp->f_mode & FMODE_WRITE) != 0;
return pipe_release(inode, decr, decw);
}
static int
pipe_read_open(struct inode *inode, struct file *filp)
{
int ret = -ENOENT;
mutex_lock(&inode->i_mutex);
if (inode->i_pipe) {
ret = 0;
inode->i_pipe->readers++;
}
mutex_unlock(&inode->i_mutex);
return ret;
}
static int
pipe_write_open(struct inode *inode, struct file *filp)
{
int ret = -ENOENT;
mutex_lock(&inode->i_mutex);
if (inode->i_pipe) {
ret = 0;
inode->i_pipe->writers++;
}
mutex_unlock(&inode->i_mutex);
return ret;
}
static int
pipe_rdwr_open(struct inode *inode, struct file *filp)
{
int ret = -ENOENT;
if (!(filp->f_mode & (FMODE_READ|FMODE_WRITE)))
return -EINVAL;
mutex_lock(&inode->i_mutex);
if (inode->i_pipe) {
ret = 0;
if (filp->f_mode & FMODE_READ)
inode->i_pipe->readers++;
if (filp->f_mode & FMODE_WRITE)
inode->i_pipe->writers++;
}
mutex_unlock(&inode->i_mutex);
return ret;
}
/*
* The file_operations structs are not static because they
* are also used in linux/fs/fifo.c to do operations on FIFOs.
*
* Pipes reuse fifos' file_operations structs.
*/
const struct file_operations read_pipefifo_fops = {
.llseek = no_llseek,
.read = do_sync_read,
.aio_read = pipe_read,
.write = bad_pipe_w,
.poll = pipe_poll,
.unlocked_ioctl = pipe_ioctl,
.open = pipe_read_open,
.release = pipe_read_release,
.fasync = pipe_read_fasync,
};
const struct file_operations write_pipefifo_fops = {
.llseek = no_llseek,
.read = bad_pipe_r,
.write = do_sync_write,
.aio_write = pipe_write,
.poll = pipe_poll,
.unlocked_ioctl = pipe_ioctl,
.open = pipe_write_open,
.release = pipe_write_release,
.fasync = pipe_write_fasync,
};
const struct file_operations rdwr_pipefifo_fops = {
.llseek = no_llseek,
.read = do_sync_read,
.aio_read = pipe_read,
.write = do_sync_write,
.aio_write = pipe_write,
.poll = pipe_poll,
.unlocked_ioctl = pipe_ioctl,
.open = pipe_rdwr_open,
.release = pipe_rdwr_release,
.fasync = pipe_rdwr_fasync,
};
struct pipe_inode_info * alloc_pipe_info(struct inode *inode)
{
struct pipe_inode_info *pipe;
@ -996,7 +838,7 @@ static struct inode * get_pipe_inode(void)
inode->i_pipe = pipe;
pipe->readers = pipe->writers = 1;
inode->i_fop = &rdwr_pipefifo_fops;
inode->i_fop = &pipefifo_fops;
/*
* Mark the inode dirty from the very beginning,
@ -1039,13 +881,13 @@ int create_pipe_files(struct file **res, int flags)
d_instantiate(path.dentry, inode);
err = -ENFILE;
f = alloc_file(&path, FMODE_WRITE, &write_pipefifo_fops);
f = alloc_file(&path, FMODE_WRITE, &pipefifo_fops);
if (IS_ERR(f))
goto err_dentry;
f->f_flags = O_WRONLY | (flags & (O_NONBLOCK | O_DIRECT));
res[0] = alloc_file(&path, FMODE_READ, &read_pipefifo_fops);
res[0] = alloc_file(&path, FMODE_READ, &pipefifo_fops);
if (IS_ERR(res[0]))
goto err_file;
@ -1164,6 +1006,7 @@ static void wake_up_partner(struct inode* inode)
static int fifo_open(struct inode *inode, struct file *filp)
{
struct pipe_inode_info *pipe;
bool is_pipe = inode->i_sb->s_magic == PIPEFS_MAGIC;
int ret;
mutex_lock(&inode->i_mutex);
@ -1187,12 +1030,11 @@ static int fifo_open(struct inode *inode, struct file *filp)
* POSIX.1 says that O_NONBLOCK means return with the FIFO
* opened, even when there is no process writing the FIFO.
*/
filp->f_op = &read_pipefifo_fops;
pipe->r_counter++;
if (pipe->readers++ == 0)
wake_up_partner(inode);
if (!pipe->writers) {
if (!is_pipe && !pipe->writers) {
if ((filp->f_flags & O_NONBLOCK)) {
/* suppress POLLHUP until we have
* seen a writer */
@ -1211,15 +1053,14 @@ static int fifo_open(struct inode *inode, struct file *filp)
* errno=ENXIO when there is no process reading the FIFO.
*/
ret = -ENXIO;
if ((filp->f_flags & O_NONBLOCK) && !pipe->readers)
if (!is_pipe && (filp->f_flags & O_NONBLOCK) && !pipe->readers)
goto err;
filp->f_op = &write_pipefifo_fops;
pipe->w_counter++;
if (!pipe->writers++)
wake_up_partner(inode);
if (!pipe->readers) {
if (!is_pipe && !pipe->readers) {
if (wait_for_partner(inode, &pipe->r_counter))
goto err_wr;
}
@ -1232,7 +1073,6 @@ static int fifo_open(struct inode *inode, struct file *filp)
* This implementation will NEVER block on a O_RDWR open, since
* the process can at least talk to itself.
*/
filp->f_op = &rdwr_pipefifo_fops;
pipe->readers++;
pipe->writers++;
@ -1272,14 +1112,17 @@ err_nocleanup:
return ret;
}
/*
* Dummy default file-operations: the only thing this does
* is contain the open that then fills in the correct operations
* depending on the access mode of the file...
*/
const struct file_operations def_fifo_fops = {
.open = fifo_open, /* will set read_ or write_pipefifo_fops */
.llseek = noop_llseek,
const struct file_operations pipefifo_fops = {
.open = fifo_open,
.llseek = no_llseek,
.read = do_sync_read,
.aio_read = pipe_read,
.write = do_sync_write,
.aio_write = pipe_write,
.poll = pipe_poll,
.unlocked_ioctl = pipe_ioctl,
.release = pipe_release,
.fasync = pipe_fasync,
};
/*

5
include/linux/fs.h
View File

@ -2080,7 +2080,6 @@ extern int sync_filesystem(struct super_block *);
extern const struct file_operations def_blk_fops;
extern const struct file_operations def_chr_fops;
extern const struct file_operations bad_sock_fops;
extern const struct file_operations def_fifo_fops;
#ifdef CONFIG_BLOCK
extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
extern int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
@ -2152,10 +2151,6 @@ extern void init_special_inode(struct inode *, umode_t, dev_t);
extern void make_bad_inode(struct inode *);
extern int is_bad_inode(struct inode *);
extern const struct file_operations read_pipefifo_fops;
extern const struct file_operations write_pipefifo_fops;
extern const struct file_operations rdwr_pipefifo_fops;
#ifdef CONFIG_BLOCK
/*
* return READ, READA, or WRITE