X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fpipe.c;h=ae17d026aaa3f496fc0bf9d8522f52d027d8dadb;hb=6c28705418de012216161b14a2ff1dda3da3d786;hp=d9644fd9cc0dfe11902a3539b0c78d7c60875611;hpb=f84d751994441292593523c7069ed147176f6cab;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/pipe.c b/fs/pipe.c index d9644fd..ae17d02 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -16,6 +16,8 @@ #include #include #include +#include +#include #include #include @@ -35,6 +37,42 @@ * -- Manfred Spraul 2002-05-09 */ +static void pipe_lock_nested(struct pipe_inode_info *pipe, int subclass) +{ + if (pipe->inode) + mutex_lock_nested(&pipe->inode->i_mutex, subclass); +} + +void pipe_lock(struct pipe_inode_info *pipe) +{ + /* + * pipe_lock() nests non-pipe inode locks (for writing to a file) + */ + pipe_lock_nested(pipe, I_MUTEX_PARENT); +} +EXPORT_SYMBOL(pipe_lock); + +void pipe_unlock(struct pipe_inode_info *pipe) +{ + if (pipe->inode) + mutex_unlock(&pipe->inode->i_mutex); +} +EXPORT_SYMBOL(pipe_unlock); + +void pipe_double_lock(struct pipe_inode_info *pipe1, + struct pipe_inode_info *pipe2) +{ + BUG_ON(pipe1 == pipe2); + + if (pipe1 < pipe2) { + pipe_lock_nested(pipe1, I_MUTEX_PARENT); + pipe_lock_nested(pipe2, I_MUTEX_CHILD); + } else { + pipe_lock_nested(pipe2, I_MUTEX_PARENT); + pipe_lock_nested(pipe1, I_MUTEX_CHILD); + } +} + /* Drop the inode semaphore and wait for a pipe event, atomically */ void pipe_wait(struct pipe_inode_info *pipe) { @@ -44,18 +82,16 @@ void pipe_wait(struct pipe_inode_info *pipe) * Pipes are system-local resources, so sleeping on them * is considered a noninteractive wait: */ - prepare_to_wait(&pipe->wait, &wait, - TASK_INTERRUPTIBLE | TASK_NONINTERACTIVE); - if (pipe->inode) - mutex_unlock(&pipe->inode->i_mutex); + prepare_to_wait(&pipe->wait, &wait, TASK_INTERRUPTIBLE); + pipe_unlock(pipe); schedule(); finish_wait(&pipe->wait, &wait); - if (pipe->inode) - mutex_lock(&pipe->inode->i_mutex); + pipe_lock(pipe); } static int -pipe_iov_copy_from_user(void *to, struct iovec *iov, unsigned long len) +pipe_iov_copy_from_user(void *to, struct iovec *iov, unsigned long len, + int atomic) { unsigned long copy; @@ -64,8 +100,13 @@ pipe_iov_copy_from_user(void *to, struct iovec *iov, unsigned long len) iov++; copy = min_t(unsigned long, len, iov->iov_len); - if (copy_from_user(to, iov->iov_base, copy)) - return -EFAULT; + if (atomic) { + if (__copy_from_user_inatomic(to, iov->iov_base, copy)) + return -EFAULT; + } else { + if (copy_from_user(to, iov->iov_base, copy)) + return -EFAULT; + } to += copy; len -= copy; iov->iov_base += copy; @@ -75,7 +116,8 @@ pipe_iov_copy_from_user(void *to, struct iovec *iov, unsigned long len) } static int -pipe_iov_copy_to_user(struct iovec *iov, const void *from, unsigned long len) +pipe_iov_copy_to_user(struct iovec *iov, const void *from, unsigned long len, + int atomic) { unsigned long copy; @@ -84,8 +126,13 @@ pipe_iov_copy_to_user(struct iovec *iov, const void *from, unsigned long len) iov++; copy = min_t(unsigned long, len, iov->iov_len); - if (copy_to_user(iov->iov_base, from, copy)) - return -EFAULT; + if (atomic) { + if (__copy_to_user_inatomic(iov->iov_base, from, copy)) + return -EFAULT; + } else { + if (copy_to_user(iov->iov_base, from, copy)) + return -EFAULT; + } from += copy; len -= copy; iov->iov_base += copy; @@ -94,6 +141,47 @@ pipe_iov_copy_to_user(struct iovec *iov, const void *from, unsigned long len) return 0; } +/* + * Attempt to pre-fault in the user memory, so we can use atomic copies. + * Returns the number of bytes not faulted in. + */ +static int iov_fault_in_pages_write(struct iovec *iov, unsigned long len) +{ + while (!iov->iov_len) + iov++; + + while (len > 0) { + unsigned long this_len; + + this_len = min_t(unsigned long, len, iov->iov_len); + if (fault_in_pages_writeable(iov->iov_base, this_len)) + break; + + len -= this_len; + iov++; + } + + return len; +} + +/* + * Pre-fault in the user memory, so we can use atomic copies. + */ +static void iov_fault_in_pages_read(struct iovec *iov, unsigned long len) +{ + while (!iov->iov_len) + iov++; + + while (len > 0) { + unsigned long this_len; + + this_len = min_t(unsigned long, len, iov->iov_len); + fault_in_pages_readable(iov->iov_base, this_len); + len -= this_len; + iov++; + } +} + static void anon_pipe_buf_release(struct pipe_inode_info *pipe, struct pipe_buffer *buf) { @@ -110,23 +198,72 @@ static void anon_pipe_buf_release(struct pipe_inode_info *pipe, page_cache_release(page); } +/** + * generic_pipe_buf_map - virtually map a pipe buffer + * @pipe: the pipe that the buffer belongs to + * @buf: the buffer that should be mapped + * @atomic: whether to use an atomic map + * + * Description: + * This function returns a kernel virtual address mapping for the + * pipe_buffer passed in @buf. If @atomic is set, an atomic map is provided + * and the caller has to be careful not to fault before calling + * the unmap function. + * + * Note that this function occupies KM_USER0 if @atomic != 0. + */ void *generic_pipe_buf_map(struct pipe_inode_info *pipe, - struct pipe_buffer *buf) + struct pipe_buffer *buf, int atomic) { + if (atomic) { + buf->flags |= PIPE_BUF_FLAG_ATOMIC; + return kmap_atomic(buf->page, KM_USER0); + } + return kmap(buf->page); } +/** + * generic_pipe_buf_unmap - unmap a previously mapped pipe buffer + * @pipe: the pipe that the buffer belongs to + * @buf: the buffer that should be unmapped + * @map_data: the data that the mapping function returned + * + * Description: + * This function undoes the mapping that ->map() provided. + */ void generic_pipe_buf_unmap(struct pipe_inode_info *pipe, - struct pipe_buffer *buf) + struct pipe_buffer *buf, void *map_data) { - kunmap(buf->page); + if (buf->flags & PIPE_BUF_FLAG_ATOMIC) { + buf->flags &= ~PIPE_BUF_FLAG_ATOMIC; + kunmap_atomic(map_data, KM_USER0); + } else + kunmap(buf->page); } -static int anon_pipe_buf_steal(struct pipe_inode_info *pipe, - struct pipe_buffer *buf) +/** + * generic_pipe_buf_steal - attempt to take ownership of a &pipe_buffer + * @pipe: the pipe that the buffer belongs to + * @buf: the buffer to attempt to steal + * + * Description: + * This function attempts to steal the &struct page attached to + * @buf. If successful, this function returns 0 and returns with + * the page locked. The caller may then reuse the page for whatever + * he wishes; the typical use is insertion into a different file + * page cache. + */ +int generic_pipe_buf_steal(struct pipe_inode_info *pipe, + struct pipe_buffer *buf) { struct page *page = buf->page; + /* + * A reference of one is golden, that means that the owner of this + * page is the only one holding a reference to it. lock the page + * and return OK. + */ if (page_count(page) == 1) { lock_page(page); return 0; @@ -135,31 +272,66 @@ static int anon_pipe_buf_steal(struct pipe_inode_info *pipe, return 1; } -void generic_pipe_buf_get(struct pipe_inode_info *info, struct pipe_buffer *buf) +/** + * generic_pipe_buf_get - get a reference to a &struct pipe_buffer + * @pipe: the pipe that the buffer belongs to + * @buf: the buffer to get a reference to + * + * Description: + * This function grabs an extra reference to @buf. It's used in + * in the tee() system call, when we duplicate the buffers in one + * pipe into another. + */ +void generic_pipe_buf_get(struct pipe_inode_info *pipe, struct pipe_buffer *buf) { page_cache_get(buf->page); } -int generic_pipe_buf_pin(struct pipe_inode_info *info, struct pipe_buffer *buf) +/** + * generic_pipe_buf_confirm - verify contents of the pipe buffer + * @info: the pipe that the buffer belongs to + * @buf: the buffer to confirm + * + * Description: + * This function does nothing, because the generic pipe code uses + * pages that are always good when inserted into the pipe. + */ +int generic_pipe_buf_confirm(struct pipe_inode_info *info, + struct pipe_buffer *buf) { return 0; } -static struct pipe_buf_operations anon_pipe_buf_ops = { +/** + * generic_pipe_buf_release - put a reference to a &struct pipe_buffer + * @pipe: the pipe that the buffer belongs to + * @buf: the buffer to put a reference to + * + * Description: + * This function releases a reference to @buf. + */ +void generic_pipe_buf_release(struct pipe_inode_info *pipe, + struct pipe_buffer *buf) +{ + page_cache_release(buf->page); +} + +static const struct pipe_buf_operations anon_pipe_buf_ops = { .can_merge = 1, .map = generic_pipe_buf_map, .unmap = generic_pipe_buf_unmap, - .pin = generic_pipe_buf_pin, + .confirm = generic_pipe_buf_confirm, .release = anon_pipe_buf_release, - .steal = anon_pipe_buf_steal, + .steal = generic_pipe_buf_steal, .get = generic_pipe_buf_get, }; static ssize_t -pipe_readv(struct file *filp, const struct iovec *_iov, - unsigned long nr_segs, loff_t *ppos) +pipe_read(struct kiocb *iocb, const struct iovec *_iov, + unsigned long nr_segs, loff_t pos) { - struct inode *inode = filp->f_dentry->d_inode; + struct file *filp = iocb->ki_filp; + struct inode *inode = filp->f_path.dentry->d_inode; struct pipe_inode_info *pipe; int do_wakeup; ssize_t ret; @@ -180,27 +352,36 @@ pipe_readv(struct file *filp, const struct iovec *_iov, if (bufs) { int curbuf = pipe->curbuf; struct pipe_buffer *buf = pipe->bufs + curbuf; - struct pipe_buf_operations *ops = buf->ops; + const struct pipe_buf_operations *ops = buf->ops; void *addr; size_t chars = buf->len; - int error; + int error, atomic; if (chars > total_len) chars = total_len; - error = ops->pin(pipe, buf); + error = ops->confirm(pipe, buf); if (error) { if (!ret) error = ret; break; } - addr = ops->map(pipe, buf); - error = pipe_iov_copy_to_user(iov, addr + buf->offset, chars); - ops->unmap(pipe, buf); + atomic = !iov_fault_in_pages_write(iov, chars); +redo: + addr = ops->map(pipe, buf, atomic); + error = pipe_iov_copy_to_user(iov, addr + buf->offset, chars, atomic); + ops->unmap(pipe, buf, addr); if (unlikely(error)) { + /* + * Just retry with the slow path if we failed. + */ + if (atomic) { + atomic = 0; + goto redo; + } if (!ret) - ret = -EFAULT; + ret = error; break; } ret += chars; @@ -250,7 +431,7 @@ pipe_readv(struct file *filp, const struct iovec *_iov, /* Signal writers asynchronously that there is more room. */ if (do_wakeup) { - wake_up_interruptible(&pipe->wait); + wake_up_interruptible_sync(&pipe->wait); kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); } if (ret > 0) @@ -259,18 +440,11 @@ pipe_readv(struct file *filp, const struct iovec *_iov, } static ssize_t -pipe_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos) +pipe_write(struct kiocb *iocb, const struct iovec *_iov, + unsigned long nr_segs, loff_t ppos) { - struct iovec iov = { .iov_base = buf, .iov_len = count }; - - return pipe_readv(filp, &iov, 1, ppos); -} - -static ssize_t -pipe_writev(struct file *filp, const struct iovec *_iov, - unsigned long nr_segs, loff_t *ppos) -{ - struct inode *inode = filp->f_dentry->d_inode; + struct file *filp = iocb->ki_filp; + struct inode *inode = filp->f_path.dentry->d_inode; struct pipe_inode_info *pipe; ssize_t ret; int do_wakeup; @@ -300,25 +474,32 @@ pipe_writev(struct file *filp, const struct iovec *_iov, int lastbuf = (pipe->curbuf + pipe->nrbufs - 1) & (PIPE_BUFFERS-1); struct pipe_buffer *buf = pipe->bufs + lastbuf; - struct pipe_buf_operations *ops = buf->ops; + const struct pipe_buf_operations *ops = buf->ops; int offset = buf->offset + buf->len; if (ops->can_merge && offset + chars <= PAGE_SIZE) { + int error, atomic = 1; void *addr; - int error; - error = ops->pin(pipe, buf); + error = ops->confirm(pipe, buf); if (error) goto out; - addr = ops->map(pipe, buf); + iov_fault_in_pages_read(iov, chars); +redo1: + addr = ops->map(pipe, buf, atomic); error = pipe_iov_copy_from_user(offset + addr, iov, - chars); - ops->unmap(pipe, buf); + chars, atomic); + ops->unmap(pipe, buf, addr); ret = error; do_wakeup = 1; - if (error) + if (error) { + if (atomic) { + atomic = 0; + goto redo1; + } goto out; + } buf->len += chars; total_len -= chars; ret = chars; @@ -341,7 +522,8 @@ pipe_writev(struct file *filp, const struct iovec *_iov, int newbuf = (pipe->curbuf + bufs) & (PIPE_BUFFERS-1); struct pipe_buffer *buf = pipe->bufs + newbuf; struct page *page = pipe->tmp_page; - int error; + char *src; + int error, atomic = 1; if (!page) { page = alloc_page(GFP_HIGHUSER); @@ -361,11 +543,27 @@ pipe_writev(struct file *filp, const struct iovec *_iov, if (chars > total_len) chars = total_len; - error = pipe_iov_copy_from_user(kmap(page), iov, chars); - kunmap(page); + iov_fault_in_pages_read(iov, chars); +redo2: + if (atomic) + src = kmap_atomic(page, KM_USER0); + else + src = kmap(page); + + error = pipe_iov_copy_from_user(src, iov, chars, + atomic); + if (atomic) + kunmap_atomic(src, KM_USER0); + else + kunmap(page); + if (unlikely(error)) { + if (atomic) { + atomic = 0; + goto redo2; + } if (!ret) - ret = -EFAULT; + ret = error; break; } ret += chars; @@ -406,7 +604,7 @@ pipe_writev(struct file *filp, const struct iovec *_iov, out: mutex_unlock(&inode->i_mutex); if (do_wakeup) { - wake_up_interruptible(&pipe->wait); + wake_up_interruptible_sync(&pipe->wait); kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); } if (ret > 0) @@ -415,15 +613,6 @@ out: } static ssize_t -pipe_write(struct file *filp, const char __user *buf, - size_t count, loff_t *ppos) -{ - struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = count }; - - return pipe_writev(filp, &iov, 1, ppos); -} - -static ssize_t bad_pipe_r(struct file *filp, char __user *buf, size_t count, loff_t *ppos) { return -EBADF; @@ -436,11 +625,9 @@ bad_pipe_w(struct file *filp, const char __user *buf, size_t count, return -EBADF; } -static int -pipe_ioctl(struct inode *pino, struct file *filp, - unsigned int cmd, unsigned long arg) +static long pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { - struct inode *inode = filp->f_dentry->d_inode; + struct inode *inode = filp->f_path.dentry->d_inode; struct pipe_inode_info *pipe; int count, buf, nrbufs; @@ -468,7 +655,7 @@ static unsigned int pipe_poll(struct file *filp, poll_table *wait) { unsigned int mask; - struct inode *inode = filp->f_dentry->d_inode; + struct inode *inode = filp->f_path.dentry->d_inode; struct pipe_inode_info *pipe = inode->i_pipe; int nrbufs; @@ -509,7 +696,7 @@ pipe_release(struct inode *inode, int decr, int decw) if (!pipe->readers && !pipe->writers) { free_pipe_info(inode); } else { - wake_up_interruptible(&pipe->wait); + wake_up_interruptible_sync(&pipe->wait); kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); } @@ -521,71 +708,59 @@ pipe_release(struct inode *inode, int decr, int decw) static int pipe_read_fasync(int fd, struct file *filp, int on) { - struct inode *inode = filp->f_dentry->d_inode; + struct inode *inode = filp->f_path.dentry->d_inode; int retval; mutex_lock(&inode->i_mutex); retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_readers); mutex_unlock(&inode->i_mutex); - if (retval < 0) - return retval; - - return 0; + return retval; } static int pipe_write_fasync(int fd, struct file *filp, int on) { - struct inode *inode = filp->f_dentry->d_inode; + struct inode *inode = filp->f_path.dentry->d_inode; int retval; mutex_lock(&inode->i_mutex); retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_writers); mutex_unlock(&inode->i_mutex); - if (retval < 0) - return retval; - - return 0; + return retval; } static int pipe_rdwr_fasync(int fd, struct file *filp, int on) { - struct inode *inode = filp->f_dentry->d_inode; + struct inode *inode = filp->f_path.dentry->d_inode; struct pipe_inode_info *pipe = inode->i_pipe; int retval; mutex_lock(&inode->i_mutex); - retval = fasync_helper(fd, filp, on, &pipe->fasync_readers); - - if (retval >= 0) + if (retval >= 0) { retval = fasync_helper(fd, filp, on, &pipe->fasync_writers); - + if (retval < 0) /* this can happen only if on == T */ + fasync_helper(-1, filp, 0, &pipe->fasync_readers); + } mutex_unlock(&inode->i_mutex); - - if (retval < 0) - return retval; - - return 0; + return retval; } static int pipe_read_release(struct inode *inode, struct file *filp) { - pipe_read_fasync(-1, filp, 0); return pipe_release(inode, 1, 0); } static int pipe_write_release(struct inode *inode, struct file *filp) { - pipe_write_fasync(-1, filp, 0); return pipe_release(inode, 0, 1); } @@ -594,7 +769,6 @@ pipe_rdwr_release(struct inode *inode, struct file *filp) { int decr, decw; - pipe_rdwr_fasync(-1, filp, 0); decr = (filp->f_mode & FMODE_READ) != 0; decw = (filp->f_mode & FMODE_WRITE) != 0; return pipe_release(inode, decr, decw); @@ -603,111 +777,95 @@ pipe_rdwr_release(struct inode *inode, struct file *filp) static int pipe_read_open(struct inode *inode, struct file *filp) { - /* We could have perhaps used atomic_t, but this and friends - below are the only places. So it doesn't seem worthwhile. */ + int ret = -ENOENT; + mutex_lock(&inode->i_mutex); - inode->i_pipe->readers++; + + if (inode->i_pipe) { + ret = 0; + inode->i_pipe->readers++; + } + mutex_unlock(&inode->i_mutex); - return 0; + return ret; } static int pipe_write_open(struct inode *inode, struct file *filp) { + int ret = -ENOENT; + mutex_lock(&inode->i_mutex); - inode->i_pipe->writers++; + + if (inode->i_pipe) { + ret = 0; + inode->i_pipe->writers++; + } + mutex_unlock(&inode->i_mutex); - return 0; + return ret; } static int pipe_rdwr_open(struct inode *inode, struct file *filp) { + int ret = -ENOENT; + mutex_lock(&inode->i_mutex); - if (filp->f_mode & FMODE_READ) - inode->i_pipe->readers++; - if (filp->f_mode & FMODE_WRITE) - inode->i_pipe->writers++; + + 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 0; + 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_fifo_fops = { - .llseek = no_llseek, - .read = pipe_read, - .readv = pipe_readv, - .write = bad_pipe_w, - .poll = pipe_poll, - .ioctl = pipe_ioctl, - .open = pipe_read_open, - .release = pipe_read_release, - .fasync = pipe_read_fasync, -}; - -const struct file_operations write_fifo_fops = { +const struct file_operations read_pipefifo_fops = { .llseek = no_llseek, - .read = bad_pipe_r, - .write = pipe_write, - .writev = pipe_writev, - .poll = pipe_poll, - .ioctl = pipe_ioctl, - .open = pipe_write_open, - .release = pipe_write_release, - .fasync = pipe_write_fasync, -}; - -const struct file_operations rdwr_fifo_fops = { - .llseek = no_llseek, - .read = pipe_read, - .readv = pipe_readv, - .write = pipe_write, - .writev = pipe_writev, - .poll = pipe_poll, - .ioctl = pipe_ioctl, - .open = pipe_rdwr_open, - .release = pipe_rdwr_release, - .fasync = pipe_rdwr_fasync, -}; - -static struct file_operations read_pipe_fops = { - .llseek = no_llseek, - .read = pipe_read, - .readv = pipe_readv, + .read = do_sync_read, + .aio_read = pipe_read, .write = bad_pipe_w, .poll = pipe_poll, - .ioctl = pipe_ioctl, + .unlocked_ioctl = pipe_ioctl, .open = pipe_read_open, .release = pipe_read_release, .fasync = pipe_read_fasync, }; -static struct file_operations write_pipe_fops = { +const struct file_operations write_pipefifo_fops = { .llseek = no_llseek, .read = bad_pipe_r, - .write = pipe_write, - .writev = pipe_writev, + .write = do_sync_write, + .aio_write = pipe_write, .poll = pipe_poll, - .ioctl = pipe_ioctl, + .unlocked_ioctl = pipe_ioctl, .open = pipe_write_open, .release = pipe_write_release, .fasync = pipe_write_fasync, }; -static struct file_operations rdwr_pipe_fops = { +const struct file_operations rdwr_pipefifo_fops = { .llseek = no_llseek, - .read = pipe_read, - .readv = pipe_readv, - .write = pipe_write, - .writev = pipe_writev, + .read = do_sync_read, + .aio_read = pipe_read, + .write = do_sync_write, + .aio_write = pipe_write, .poll = pipe_poll, - .ioctl = pipe_ioctl, + .unlocked_ioctl = pipe_ioctl, .open = pipe_rdwr_open, .release = pipe_rdwr_release, .fasync = pipe_rdwr_fasync, @@ -750,11 +908,28 @@ void free_pipe_info(struct inode *inode) static struct vfsmount *pipe_mnt __read_mostly; static int pipefs_delete_dentry(struct dentry *dentry) { - return 1; + /* + * At creation time, we pretended this dentry was hashed + * (by clearing DCACHE_UNHASHED bit in d_flags) + * At delete time, we restore the truth : not hashed. + * (so that dput() can proceed correctly) + */ + dentry->d_flags |= DCACHE_UNHASHED; + return 0; } -static struct dentry_operations pipefs_dentry_operations = { +/* + * pipefs_dname() is called from d_path(). + */ +static char *pipefs_dname(struct dentry *dentry, char *buffer, int buflen) +{ + return dynamic_dname(dentry, buffer, buflen, "pipe:[%lu]", + dentry->d_inode->i_ino); +} + +static const struct dentry_operations pipefs_dentry_operations = { .d_delete = pipefs_delete_dentry, + .d_dname = pipefs_dname, }; static struct inode * get_pipe_inode(void) @@ -771,7 +946,7 @@ static struct inode * get_pipe_inode(void) inode->i_pipe = pipe; pipe->readers = pipe->writers = 1; - inode->i_fop = &rdwr_pipe_fops; + inode->i_fop = &rdwr_pipefifo_fops; /* * Mark the inode dirty from the very beginning, @@ -781,10 +956,9 @@ static struct inode * get_pipe_inode(void) */ inode->i_state = I_DIRTY; inode->i_mode = S_IFIFO | S_IRUSR | S_IWUSR; - inode->i_uid = current->fsuid; - inode->i_gid = current->fsgid; + inode->i_uid = current_fsuid(); + inode->i_gid = current_fsgid(); inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; - inode->i_blksize = PAGE_SIZE; return inode; @@ -795,87 +969,151 @@ fail_inode: return NULL; } -int do_pipe(int *fd) +struct file *create_write_pipe(int flags) { - struct qstr this; - char name[32]; + int err; + struct inode *inode; + struct file *f; struct dentry *dentry; - struct inode * inode; - struct file *f1, *f2; - int error; - int i, j; - - error = -ENFILE; - f1 = get_empty_filp(); - if (!f1) - goto no_files; - - f2 = get_empty_filp(); - if (!f2) - goto close_f1; + struct qstr name = { .name = "" }; + err = -ENFILE; inode = get_pipe_inode(); if (!inode) - goto close_f12; + goto err; - error = get_unused_fd(); - if (error < 0) - goto close_f12_inode; - i = error; - - error = get_unused_fd(); - if (error < 0) - goto close_f12_inode_i; - j = error; - - error = -ENOMEM; - sprintf(name, "[%lu]", inode->i_ino); - this.name = name; - this.len = strlen(name); - this.hash = inode->i_ino; /* will go */ - dentry = d_alloc(pipe_mnt->mnt_sb->s_root, &this); + err = -ENOMEM; + dentry = d_alloc(pipe_mnt->mnt_sb->s_root, &name); if (!dentry) - goto close_f12_inode_i_j; + goto err_inode; dentry->d_op = &pipefs_dentry_operations; - d_add(dentry, inode); - f1->f_vfsmnt = f2->f_vfsmnt = mntget(mntget(pipe_mnt)); - f1->f_dentry = f2->f_dentry = dget(dentry); - f1->f_mapping = f2->f_mapping = inode->i_mapping; - - /* read file */ - f1->f_pos = f2->f_pos = 0; - f1->f_flags = O_RDONLY; - f1->f_op = &read_pipe_fops; - f1->f_mode = FMODE_READ; - f1->f_version = 0; - - /* write file */ - f2->f_flags = O_WRONLY; - f2->f_op = &write_pipe_fops; - f2->f_mode = FMODE_WRITE; - f2->f_version = 0; - - fd_install(i, f1); - fd_install(j, f2); - fd[0] = i; - fd[1] = j; + /* + * We dont want to publish this dentry into global dentry hash table. + * We pretend dentry is already hashed, by unsetting DCACHE_UNHASHED + * This permits a working /proc/$pid/fd/XXX on pipes + */ + dentry->d_flags &= ~DCACHE_UNHASHED; + d_instantiate(dentry, inode); - return 0; + err = -ENFILE; + f = alloc_file(pipe_mnt, dentry, FMODE_WRITE, &write_pipefifo_fops); + if (!f) + goto err_dentry; + f->f_mapping = inode->i_mapping; + + f->f_flags = O_WRONLY | (flags & O_NONBLOCK); + f->f_version = 0; -close_f12_inode_i_j: - put_unused_fd(j); -close_f12_inode_i: - put_unused_fd(i); -close_f12_inode: + return f; + + err_dentry: + free_pipe_info(inode); + dput(dentry); + return ERR_PTR(err); + + err_inode: free_pipe_info(inode); iput(inode); -close_f12: - put_filp(f2); -close_f1: - put_filp(f1); -no_files: - return error; + err: + return ERR_PTR(err); +} + +void free_write_pipe(struct file *f) +{ + free_pipe_info(f->f_dentry->d_inode); + path_put(&f->f_path); + put_filp(f); +} + +struct file *create_read_pipe(struct file *wrf, int flags) +{ + struct file *f = get_empty_filp(); + if (!f) + return ERR_PTR(-ENFILE); + + /* Grab pipe from the writer */ + f->f_path = wrf->f_path; + path_get(&wrf->f_path); + f->f_mapping = wrf->f_path.dentry->d_inode->i_mapping; + + f->f_pos = 0; + f->f_flags = O_RDONLY | (flags & O_NONBLOCK); + f->f_op = &read_pipefifo_fops; + f->f_mode = FMODE_READ; + f->f_version = 0; + + return f; +} + +int do_pipe_flags(int *fd, int flags) +{ + struct file *fw, *fr; + int error; + int fdw, fdr; + + if (flags & ~(O_CLOEXEC | O_NONBLOCK)) + return -EINVAL; + + fw = create_write_pipe(flags); + if (IS_ERR(fw)) + return PTR_ERR(fw); + fr = create_read_pipe(fw, flags); + error = PTR_ERR(fr); + if (IS_ERR(fr)) + goto err_write_pipe; + + error = get_unused_fd_flags(flags); + if (error < 0) + goto err_read_pipe; + fdr = error; + + error = get_unused_fd_flags(flags); + if (error < 0) + goto err_fdr; + fdw = error; + + audit_fd_pair(fdr, fdw); + fd_install(fdr, fr); + fd_install(fdw, fw); + fd[0] = fdr; + fd[1] = fdw; + + return 0; + + err_fdr: + put_unused_fd(fdr); + err_read_pipe: + path_put(&fr->f_path); + put_filp(fr); + err_write_pipe: + free_write_pipe(fw); + return error; +} + +/* + * sys_pipe() is the normal C calling standard for creating + * a pipe. It's not the way Unix traditionally does this, though. + */ +SYSCALL_DEFINE2(pipe2, int __user *, fildes, int, flags) +{ + int fd[2]; + int error; + + error = do_pipe_flags(fd, flags); + if (!error) { + if (copy_to_user(fildes, fd, sizeof(fd))) { + sys_close(fd[0]); + sys_close(fd[1]); + error = -EFAULT; + } + } + return error; +} + +SYSCALL_DEFINE1(pipe, int __user *, fildes) +{ + return sys_pipe2(fildes, 0); } /* @@ -884,12 +1122,11 @@ no_files: * any operations on the root directory. However, we need a non-trivial * d_name - pipe: will go nicely and kill the special-casing in procfs. */ - -static struct super_block * -pipefs_get_sb(struct file_system_type *fs_type, int flags, - const char *dev_name, void *data) +static int pipefs_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, void *data, + struct vfsmount *mnt) { - return get_sb_pseudo(fs_type, "pipe:", NULL, PIPEFS_MAGIC); + return get_sb_pseudo(fs_type, "pipe:", NULL, PIPEFS_MAGIC, mnt); } static struct file_system_type pipe_fs_type = {