From 599a0ac14e065b7c08471ef2e75a504b7dec9267 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 12 Mar 2013 09:58:10 -0400 Subject: pipe: fold file_operations instances in one Signed-off-by: Al Viro --- fs/inode.c | 2 +- fs/internal.h | 5 ++ fs/pipe.c | 221 ++++++++--------------------------------------------- include/linux/fs.h | 5 -- 4 files changed, 38 insertions(+), 195 deletions(-) diff --git a/fs/inode.c b/fs/inode.c index f5f7c06c36fb..5b76d9b1a884 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -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 diff --git a/fs/internal.h b/fs/internal.h index 4be78237d896..eaa75f75b625 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -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; diff --git a/fs/pipe.c b/fs/pipe.c index aed80c25cd40..099ac3bf89f9 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -25,6 +25,8 @@ #include #include +#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, }; /* diff --git a/include/linux/fs.h b/include/linux/fs.h index 578a66e6ee72..b1f28b02ede6 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -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 -- cgit