diff options
| -rw-r--r-- | fs/Makefile | 2 | ||||
| -rw-r--r-- | fs/fifo.c | 153 | ||||
| -rw-r--r-- | fs/pipe.c | 138 |
3 files changed, 139 insertions, 154 deletions
diff --git a/fs/Makefile b/fs/Makefile index 9d53192..b691a96 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -7,7 +7,7 @@ obj-y := open.o read_write.o file_table.o super.o \ char_dev.o stat.o exec.o pipe.o namei.o fcntl.o \ - ioctl.o readdir.o select.o fifo.o dcache.o inode.o \ + ioctl.o readdir.o select.o dcache.o inode.o \ attr.o bad_inode.o file.o filesystems.o namespace.o \ seq_file.o xattr.o libfs.o fs-writeback.o \ pnode.o drop_caches.o splice.o sync.o utimes.o \ diff --git a/fs/fifo.c b/fs/fifo.c deleted file mode 100644 index cf6f434..0000000 --- a/fs/fifo.c +++ /dev/null @@ -1,153 +0,0 @@ -/* - * linux/fs/fifo.c - * - * written by Paul H. Hargrove - * - * Fixes: - * 10-06-1999, AV: fixed OOM handling in fifo_open(), moved - * initialization there, switched to external - * allocation of pipe_inode_info. - */ - -#include <linux/mm.h> -#include <linux/fs.h> -#include <linux/sched.h> -#include <linux/pipe_fs_i.h> - -static int wait_for_partner(struct inode* inode, unsigned int *cnt) -{ - int cur = *cnt; - - while (cur == *cnt) { - pipe_wait(inode->i_pipe); - if (signal_pending(current)) - break; - } - return cur == *cnt ? -ERESTARTSYS : 0; -} - -static void wake_up_partner(struct inode* inode) -{ - wake_up_interruptible(&inode->i_pipe->wait); -} - -static int fifo_open(struct inode *inode, struct file *filp) -{ - struct pipe_inode_info *pipe; - int ret; - - mutex_lock(&inode->i_mutex); - pipe = inode->i_pipe; - if (!pipe) { - ret = -ENOMEM; - pipe = alloc_pipe_info(inode); - if (!pipe) - goto err_nocleanup; - inode->i_pipe = pipe; - } - filp->f_version = 0; - - /* We can only do regular read/write on fifos */ - filp->f_mode &= (FMODE_READ | FMODE_WRITE); - - switch (filp->f_mode) { - case FMODE_READ: - /* - * O_RDONLY - * 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 ((filp->f_flags & O_NONBLOCK)) { - /* suppress POLLHUP until we have - * seen a writer */ - filp->f_version = pipe->w_counter; - } else { - if (wait_for_partner(inode, &pipe->w_counter)) - goto err_rd; - } - } - break; - - case FMODE_WRITE: - /* - * O_WRONLY - * POSIX.1 says that O_NONBLOCK means return -1 with - * errno=ENXIO when there is no process reading the FIFO. - */ - ret = -ENXIO; - if ((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 (wait_for_partner(inode, &pipe->r_counter)) - goto err_wr; - } - break; - - case FMODE_READ | FMODE_WRITE: - /* - * O_RDWR - * POSIX.1 leaves this case "undefined" when O_NONBLOCK is set. - * 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++; - pipe->r_counter++; - pipe->w_counter++; - if (pipe->readers == 1 || pipe->writers == 1) - wake_up_partner(inode); - break; - - default: - ret = -EINVAL; - goto err; - } - - /* Ok! */ - mutex_unlock(&inode->i_mutex); - return 0; - -err_rd: - if (!--pipe->readers) - wake_up_interruptible(&pipe->wait); - ret = -ERESTARTSYS; - goto err; - -err_wr: - if (!--pipe->writers) - wake_up_interruptible(&pipe->wait); - ret = -ERESTARTSYS; - goto err; - -err: - if (!pipe->readers && !pipe->writers) - free_pipe_info(inode); - -err_nocleanup: - mutex_unlock(&inode->i_mutex); - 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, -}; @@ -1144,6 +1144,144 @@ SYSCALL_DEFINE1(pipe, int __user *, fildes) return sys_pipe2(fildes, 0); } +static int wait_for_partner(struct inode* inode, unsigned int *cnt) +{ + int cur = *cnt; + + while (cur == *cnt) { + pipe_wait(inode->i_pipe); + if (signal_pending(current)) + break; + } + return cur == *cnt ? -ERESTARTSYS : 0; +} + +static void wake_up_partner(struct inode* inode) +{ + wake_up_interruptible(&inode->i_pipe->wait); +} + +static int fifo_open(struct inode *inode, struct file *filp) +{ + struct pipe_inode_info *pipe; + int ret; + + mutex_lock(&inode->i_mutex); + pipe = inode->i_pipe; + if (!pipe) { + ret = -ENOMEM; + pipe = alloc_pipe_info(inode); + if (!pipe) + goto err_nocleanup; + inode->i_pipe = pipe; + } + filp->f_version = 0; + + /* We can only do regular read/write on fifos */ + filp->f_mode &= (FMODE_READ | FMODE_WRITE); + + switch (filp->f_mode) { + case FMODE_READ: + /* + * O_RDONLY + * 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 ((filp->f_flags & O_NONBLOCK)) { + /* suppress POLLHUP until we have + * seen a writer */ + filp->f_version = pipe->w_counter; + } else { + if (wait_for_partner(inode, &pipe->w_counter)) + goto err_rd; + } + } + break; + + case FMODE_WRITE: + /* + * O_WRONLY + * POSIX.1 says that O_NONBLOCK means return -1 with + * errno=ENXIO when there is no process reading the FIFO. + */ + ret = -ENXIO; + if ((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 (wait_for_partner(inode, &pipe->r_counter)) + goto err_wr; + } + break; + + case FMODE_READ | FMODE_WRITE: + /* + * O_RDWR + * POSIX.1 leaves this case "undefined" when O_NONBLOCK is set. + * 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++; + pipe->r_counter++; + pipe->w_counter++; + if (pipe->readers == 1 || pipe->writers == 1) + wake_up_partner(inode); + break; + + default: + ret = -EINVAL; + goto err; + } + + /* Ok! */ + mutex_unlock(&inode->i_mutex); + return 0; + +err_rd: + if (!--pipe->readers) + wake_up_interruptible(&pipe->wait); + ret = -ERESTARTSYS; + goto err; + +err_wr: + if (!--pipe->writers) + wake_up_interruptible(&pipe->wait); + ret = -ERESTARTSYS; + goto err; + +err: + if (!pipe->readers && !pipe->writers) + free_pipe_info(inode); + +err_nocleanup: + mutex_unlock(&inode->i_mutex); + 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, +}; + /* * Allocate a new array of pipe buffers and copy the info over. Returns the * pipe size if successful, or return -ERROR on error. |
