static int pipe_release(struct inode * inode) { if (!PIPE_READERS(*inode) && !PIPE_WRITERS(*inode)) { free_page((unsigned long) PIPE_BASE(*inode)); PIPE_BASE(*inode) = NULL; } wake_up_interruptible(&PIPE_WAIT(*inode)); return 0; }
struct inode *get_pipe_inode(void) { register struct inode *inode; extern struct inode_operations pipe_inode_operations; if ((inode = get_empty_inode())) { if (!(PIPE_BASE(*inode) = get_pipe_mem())) { iput(inode); return NULL; } inode->i_op = &pipe_inode_operations; inode->i_count = 2; /* sum of readers/writers */ PIPE_START(*inode) = PIPE_LEN(*inode) = 0; PIPE_RD_OPENERS(*inode) = PIPE_WR_OPENERS(*inode) = 0; PIPE_READERS(*inode) = PIPE_WRITERS(*inode) = 1; PIPE_LOCK(*inode) = 0; inode->i_pipe = 1; inode->i_mode |= S_IFIFO | S_IRUSR | S_IWUSR; inode->i_uid = current->euid; inode->i_gid = (__u8) current->egid; inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; #if 0 inode->i_blksize = PAGE_SIZE; #endif } return inode; }
struct inode* pipe_new(struct inode* inode) { unsigned long page; page = __get_free_page(GFP_USER); if (!page) return NULL; inode->i_pipe = kmalloc(sizeof(struct pipe_inode_info), GFP_KERNEL); if (!inode->i_pipe) goto fail_page; init_waitqueue_head(PIPE_WAIT(*inode)); PIPE_BASE(*inode) = (char*) page; PIPE_START(*inode) = PIPE_LEN(*inode) = 0; PIPE_READERS(*inode) = PIPE_WRITERS(*inode) = 0; PIPE_WAITING_WRITERS(*inode) = 0; PIPE_RCOUNTER(*inode) = PIPE_WCOUNTER(*inode) = 1; *PIPE_FASYNC_READERS(*inode) = *PIPE_FASYNC_WRITERS(*inode) = NULL; return inode; fail_page: free_page(page); return NULL; }
static struct inode * get_pipe_inode(void) { extern struct inode_operations pipe_inode_operations; struct inode *inode = get_empty_inode(); if (inode) { unsigned long page = __get_free_page(GFP_USER); if (!page) { iput(inode); inode = NULL; } else { PIPE_BASE(*inode) = (char *) page; inode->i_op = &pipe_inode_operations; PIPE_WAIT(*inode) = NULL; PIPE_START(*inode) = PIPE_LEN(*inode) = 0; PIPE_RD_OPENERS(*inode) = PIPE_WR_OPENERS(*inode) = 0; PIPE_READERS(*inode) = PIPE_WRITERS(*inode) = 1; PIPE_LOCK(*inode) = 0; /* * Mark the inode dirty from the very beginning, * that way it will never be moved to the dirty * list because "mark_inode_dirty()" will think * that it already _is_ on the dirty list. */ 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_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; inode->i_blksize = PAGE_SIZE; } } return inode; }
static ssize_t pipe_read(struct file * filp, char * buf, size_t count, loff_t *ppos) { struct inode * inode = filp->f_dentry->d_inode; ssize_t chars = 0, size = 0, read = 0; char *pipebuf; if (ppos != &filp->f_pos) return -ESPIPE; if ( !count ) return 0; if (filp->f_flags & O_NONBLOCK) { if (PIPE_LOCK(*inode)) return -EAGAIN; if (PIPE_EMPTY(*inode)) { if (PIPE_WRITERS(*inode)) return -EAGAIN; else return 0; } } else while (PIPE_EMPTY(*inode) || PIPE_LOCK(*inode)) { if (PIPE_EMPTY(*inode)) { if (!PIPE_WRITERS(*inode) || !count) return 0; } if (signal_pending(current)) return -ERESTARTSYS; interruptible_sleep_on(&PIPE_WAIT(*inode)); } PIPE_LOCK(*inode)++; while (count>0 && (size = PIPE_SIZE(*inode))) { chars = PIPE_MAX_RCHUNK(*inode); if (chars > count) chars = count; if (chars > size) chars = size; read += chars; pipebuf = PIPE_BASE(*inode)+PIPE_START(*inode); PIPE_START(*inode) += chars; PIPE_START(*inode) &= (PIPE_BUF-1); PIPE_LEN(*inode) -= chars; count -= chars; copy_to_user(buf, pipebuf, chars ); buf += chars; } PIPE_LOCK(*inode)--; wake_up_interruptible(&PIPE_WAIT(*inode)); if (read) { UPDATE_ATIME(inode); return read; } if (PIPE_WRITERS(*inode)) return -EAGAIN; return 0; }
static int pipe_rdwr_open(register struct inode *inode, register struct file *filp) { debug("PIPE: rdwr called.\n"); if(!PIPE_BASE(*inode)) { if(!(PIPE_BASE(*inode) = get_pipe_mem())) return -ENOMEM; #if 0 /* next fields already set to zero by get_empty_inode() */ PIPE_START(*inode) = PIPE_LEN(*inode) = 0; PIPE_RD_OPENERS(*inode) = PIPE_WR_OPENERS(*inode) = 0; PIPE_READERS(*inode) = PIPE_WRITERS(*inode) = 0; PIPE_LOCK(*inode) = 0; #endif } if (filp->f_mode & FMODE_READ) { (inode->u.pipe_i.readers)++; if(inode->u.pipe_i.writers > 0) { if(inode->u.pipe_i.readers < 2) wake_up_interruptible(&(inode->u.pipe_i.wait)); } else { if(!(filp->f_flags & O_NONBLOCK) && (inode->i_sb)) while(!(inode->u.pipe_i.writers)) interruptible_sleep_on(&(inode->u.pipe_i.wait)); } } if (filp->f_mode & FMODE_WRITE) { (inode->u.pipe_i.writers)++; if(inode->u.pipe_i.readers > 0) { if(inode->u.pipe_i.writers < 2) wake_up_interruptible(&(inode->u.pipe_i.wait)); } else { if(filp->f_flags & O_NONBLOCK) return -ENXIO; while(!(inode->u.pipe_i.readers)) interruptible_sleep_on(&(inode->u.pipe_i.wait)); } } return 0; }
void init_fifo(struct inode * inode) { inode->i_op = &fifo_inode_operations; inode->i_pipe = 1; PIPE_LOCK(*inode) = 0; PIPE_BASE(*inode) = NULL; PIPE_START(*inode) = PIPE_LEN(*inode) = 0; PIPE_RD_OPENERS(*inode) = PIPE_WR_OPENERS(*inode) = 0; PIPE_WAIT(*inode) = NULL; PIPE_READERS(*inode) = PIPE_WRITERS(*inode) = 0; }
void minix_read_inode(struct inode * inode) { struct buffer_head * bh; struct minix_inode * raw_inode; int block; block = 2 + inode->i_sb->u.minix_sb.s_imap_blocks + inode->i_sb->u.minix_sb.s_zmap_blocks + (inode->i_ino-1)/MINIX_INODES_PER_BLOCK; if (!(bh=bread(inode->i_dev,block, BLOCK_SIZE))) panic("unable to read i-node block"); raw_inode = ((struct minix_inode *) bh->b_data) + (inode->i_ino-1)%MINIX_INODES_PER_BLOCK; inode->i_mode = raw_inode->i_mode; inode->i_uid = raw_inode->i_uid; inode->i_gid = raw_inode->i_gid; inode->i_nlink = raw_inode->i_nlinks; inode->i_size = raw_inode->i_size; inode->i_mtime = inode->i_atime = inode->i_ctime = raw_inode->i_time; inode->i_blocks = inode->i_blksize = 0; if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) inode->i_rdev = raw_inode->i_zone[0]; else for (block = 0; block < 9; block++) inode->u.minix_i.i_data[block] = raw_inode->i_zone[block]; brelse(bh); inode->i_op = NULL; if (S_ISREG(inode->i_mode)) inode->i_op = &minix_file_inode_operations; else if (S_ISDIR(inode->i_mode)) inode->i_op = &minix_dir_inode_operations; else if (S_ISLNK(inode->i_mode)) inode->i_op = &minix_symlink_inode_operations; else if (S_ISCHR(inode->i_mode)) inode->i_op = &minix_chrdev_inode_operations; else if (S_ISBLK(inode->i_mode)) inode->i_op = &minix_blkdev_inode_operations; else if (S_ISFIFO(inode->i_mode)) { inode->i_op = &minix_fifo_inode_operations; inode->i_pipe = 1; PIPE_BASE(*inode) = NULL; PIPE_HEAD(*inode) = PIPE_TAIL(*inode) = 0; PIPE_READ_WAIT(*inode) = PIPE_WRITE_WAIT(*inode) = NULL; PIPE_READERS(*inode) = PIPE_WRITERS(*inode) = 0; } }
int do_pipe(int *fd) { struct qstr this; char name[32]; 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; inode = get_pipe_inode(); if (!inode) goto close_f12; 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); if (!dentry) goto close_f12_inode_i_j; 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); /* read file */ f1->f_pos = f2->f_pos = 0; f1->f_flags = O_RDONLY; f1->f_op = &read_pipe_fops; f1->f_mode = 1; f1->f_version = 0; /* write file */ f2->f_flags = O_WRONLY; f2->f_op = &write_pipe_fops; f2->f_mode = 2; f2->f_version = 0; fd_install(i, f1); fd_install(j, f2); fd[0] = i; fd[1] = j; return 0; close_f12_inode_i_j: put_unused_fd(j); close_f12_inode_i: put_unused_fd(i); close_f12_inode: free_page((unsigned long) PIPE_BASE(*inode)); kfree(inode->i_pipe); inode->i_pipe = NULL; iput(inode); close_f12: put_filp(f2); close_f1: put_filp(f1); no_files: return error; }
static ssize_t pipe_read(struct file *filp, char *buf, size_t count, loff_t *ppos) { struct inode *inode = filp->f_dentry->d_inode; ssize_t size, read, ret; /* Seeks are not allowed on pipes. */ ret = -ESPIPE; read = 0; if (ppos != &filp->f_pos) goto out_nolock; /* Always return 0 on null read. */ ret = 0; if (count == 0) goto out_nolock; /* Get the pipe semaphore */ ret = -ERESTARTSYS; if (down_interruptible(PIPE_SEM(*inode))) goto out_nolock; if (PIPE_EMPTY(*inode)) { do_more_read: ret = 0; if (!PIPE_WRITERS(*inode)) goto out; ret = -EAGAIN; if (filp->f_flags & O_NONBLOCK) goto out; for (;;) { PIPE_WAITING_READERS(*inode)++; pipe_wait(inode); PIPE_WAITING_READERS(*inode)--; ret = -ERESTARTSYS; if (signal_pending(current)) goto out; ret = 0; if (!PIPE_EMPTY(*inode)) break; if (!PIPE_WRITERS(*inode)) goto out; } } /* Read what data is available. */ ret = -EFAULT; while (count > 0 && (size = PIPE_LEN(*inode))) { char *pipebuf = PIPE_BASE(*inode) + PIPE_START(*inode); ssize_t chars = PIPE_MAX_RCHUNK(*inode); if (chars > count) chars = count; if (chars > size) chars = size; if (copy_to_user(buf, pipebuf, chars)) goto out; read += chars; PIPE_START(*inode) += chars; PIPE_START(*inode) &= (PIPE_SIZE - 1); PIPE_LEN(*inode) -= chars; count -= chars; buf += chars; } /* Cache behaviour optimization */ if (!PIPE_LEN(*inode)) PIPE_START(*inode) = 0; if (count && PIPE_WAITING_WRITERS(*inode) && !(filp->f_flags & O_NONBLOCK)) { /* * We know that we are going to sleep: signal * writers synchronously that there is more * room. */ wake_up_interruptible_sync(PIPE_WAIT(*inode)); if (!PIPE_EMPTY(*inode)) BUG(); goto do_more_read; } /* Signal writers asynchronously that there is more room. */ wake_up_interruptible(PIPE_WAIT(*inode)); ret = read; out: up(PIPE_SEM(*inode)); out_nolock: if (read) ret = read; UPDATE_ATIME(inode); return ret; }
static ssize_t pipe_write(struct file *filp, const char *buf, size_t count, loff_t *ppos) { struct inode *inode = filp->f_dentry->d_inode; ssize_t free, written, ret; /* Seeks are not allowed on pipes. */ ret = -ESPIPE; written = 0; if (ppos != &filp->f_pos) goto out_nolock; /* Null write succeeds. */ ret = 0; if (count == 0) goto out_nolock; ret = -ERESTARTSYS; if (down_interruptible(PIPE_SEM(*inode))) goto out_nolock; /* No readers yields SIGPIPE. */ if (!PIPE_READERS(*inode)) goto sigpipe; /* If count <= PIPE_BUF, we have to make it atomic. */ free = (count <= PIPE_BUF ? count : 1); /* Wait, or check for, available space. */ if (filp->f_flags & O_NONBLOCK) { ret = -EAGAIN; if (PIPE_FREE(*inode) < free) goto out; } else { while (PIPE_FREE(*inode) < free) { PIPE_WAITING_WRITERS(*inode)++; pipe_wait(inode); PIPE_WAITING_WRITERS(*inode)--; ret = -ERESTARTSYS; if (signal_pending(current)) goto out; if (!PIPE_READERS(*inode)) goto sigpipe; } } /* Copy into available space. */ ret = -EFAULT; while (count > 0) { int space; char *pipebuf = PIPE_BASE(*inode) + PIPE_END(*inode); ssize_t chars = PIPE_MAX_WCHUNK(*inode); if ((space = PIPE_FREE(*inode)) != 0) { if (chars > count) chars = count; if (chars > space) chars = space; if (copy_from_user(pipebuf, buf, chars)) goto out; written += chars; PIPE_LEN(*inode) += chars; count -= chars; buf += chars; space = PIPE_FREE(*inode); continue; } ret = written; if (filp->f_flags & O_NONBLOCK) break; do { /* * Synchronous wake-up: it knows that this process * is going to give up this CPU, so it doesn't have * to do idle reschedules. */ wake_up_interruptible_sync(PIPE_WAIT(*inode)); PIPE_WAITING_WRITERS(*inode)++; pipe_wait(inode); PIPE_WAITING_WRITERS(*inode)--; if (signal_pending(current)) goto out; if (!PIPE_READERS(*inode)) goto sigpipe; } while (!PIPE_FREE(*inode)); ret = -EFAULT; } /* Signal readers asynchronously that there is more data. */ wake_up_interruptible(PIPE_WAIT(*inode)); update_mctime(inode); out: up(PIPE_SEM(*inode)); out_nolock: if (written) ret = written; return ret; sigpipe: if (written) goto out; up(PIPE_SEM(*inode)); send_sig(SIGPIPE, current, 0); return -EPIPE; }
static ssize_t pipe_readv(struct file *filp, const struct iovec *_iov, unsigned long nr_segs, loff_t *ppos) { struct inode *inode = filp->f_dentry->d_inode; int do_wakeup; ssize_t ret; struct iovec *iov = (struct iovec *)_iov; size_t total_len; total_len = iov_length(iov, nr_segs); /* Null read succeeds. */ if (unlikely(total_len == 0)) return 0; do_wakeup = 0; ret = 0; down(PIPE_SEM(*inode)); for (;;) { int size = PIPE_LEN(*inode); if (size) { char *pipebuf = PIPE_BASE(*inode) + PIPE_START(*inode); ssize_t chars = PIPE_MAX_RCHUNK(*inode); if (chars > total_len) chars = total_len; if (chars > size) chars = size; if (pipe_iov_copy_to_user(iov, pipebuf, chars)) { if (!ret) ret = -EFAULT; break; } ret += chars; PIPE_START(*inode) += chars; PIPE_START(*inode) &= (PIPE_SIZE - 1); PIPE_LEN(*inode) -= chars; total_len -= chars; do_wakeup = 1; if (!total_len) break; /* common path: read succeeded */ } if (PIPE_LEN(*inode)) /* test for cyclic buffers */ continue; if (!PIPE_WRITERS(*inode)) break; if (!PIPE_WAITING_WRITERS(*inode)) { /* syscall merging: Usually we must not sleep * if O_NONBLOCK is set, or if we got some data. * But if a writer sleeps in kernel space, then * we can wait for that data without violating POSIX. */ if (ret) break; if (filp->f_flags & O_NONBLOCK) { ret = -EAGAIN; break; } } if (signal_pending(current)) { if (!ret) ret = -ERESTARTSYS; break; } if (do_wakeup) { wake_up_interruptible_sync(PIPE_WAIT(*inode)); kill_fasync(PIPE_FASYNC_WRITERS(*inode), SIGIO, POLL_OUT); } pipe_wait(inode); } up(PIPE_SEM(*inode)); /* Signal writers asynchronously that there is more room. */ if (do_wakeup) { wake_up_interruptible(PIPE_WAIT(*inode)); kill_fasync(PIPE_FASYNC_WRITERS(*inode), SIGIO, POLL_OUT); } /* * Hack: we turn off atime updates for -RT kernels. * Who uses them on pipes anyway? */ #ifndef CONFIG_PREEMPT_RT if (ret > 0) file_accessed(filp); #endif return ret; }
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; ssize_t ret; size_t min; int do_wakeup; struct iovec *iov = (struct iovec *)_iov; size_t total_len; total_len = iov_length(iov, nr_segs); /* Null write succeeds. */ if (unlikely(total_len == 0)) return 0; do_wakeup = 0; ret = 0; min = total_len; if (min > PIPE_BUF) min = 1; down(PIPE_SEM(*inode)); for (;;) { int free; if (!PIPE_READERS(*inode)) { send_sig(SIGPIPE, current, 0); if (!ret) ret = -EPIPE; break; } free = PIPE_FREE(*inode); if (free >= min) { /* transfer data */ ssize_t chars = PIPE_MAX_WCHUNK(*inode); char *pipebuf = PIPE_BASE(*inode) + PIPE_END(*inode); /* Always wakeup, even if the copy fails. Otherwise * we lock up (O_NONBLOCK-)readers that sleep due to * syscall merging. */ do_wakeup = 1; if (chars > total_len) chars = total_len; if (chars > free) chars = free; if (pipe_iov_copy_from_user(pipebuf, iov, chars)) { if (!ret) ret = -EFAULT; break; } ret += chars; PIPE_LEN(*inode) += chars; total_len -= chars; if (!total_len) break; } if (PIPE_FREE(*inode) && ret) { /* handle cyclic data buffers */ min = 1; continue; } if (filp->f_flags & O_NONBLOCK) { if (!ret) ret = -EAGAIN; break; } if (signal_pending(current)) { if (!ret) ret = -ERESTARTSYS; break; } if (do_wakeup) { wake_up_interruptible_sync(PIPE_WAIT(*inode)); kill_fasync(PIPE_FASYNC_READERS(*inode), SIGIO, POLL_IN); do_wakeup = 0; } PIPE_WAITING_WRITERS(*inode)++; pipe_wait(inode); PIPE_WAITING_WRITERS(*inode)--; } up(PIPE_SEM(*inode)); if (do_wakeup) { wake_up_interruptible(PIPE_WAIT(*inode)); kill_fasync(PIPE_FASYNC_READERS(*inode), SIGIO, POLL_IN); } /* * Hack: we turn off atime updates for -RT kernels. * Who uses them on pipes anyway? */ #ifndef CONFIG_PREEMPT_RT if (ret > 0) inode_update_time(inode, 1); /* mtime and ctime */ #endif return ret; }
static ssize_t pipe_write(struct file * filp, const char * buf, size_t count, loff_t *ppos) { struct inode * inode = filp->f_dentry->d_inode; ssize_t chars = 0, free = 0, written = 0, err=0; char *pipebuf; if (ppos != &filp->f_pos) return -ESPIPE; if (!PIPE_READERS(*inode)) { /* no readers */ send_sig(SIGPIPE,current,0); return -EPIPE; } /* if count <= PIPE_BUF, we have to make it atomic */ if (count <= PIPE_BUF) free = count; else free = 1; /* can't do it atomically, wait for any free space */ up(&inode->i_sem); if (down_interruptible(&inode->i_atomic_write)) { down(&inode->i_sem); return -ERESTARTSYS; } while (count>0) { while ((PIPE_FREE(*inode) < free) || PIPE_LOCK(*inode)) { if (!PIPE_READERS(*inode)) { /* no readers */ send_sig(SIGPIPE,current,0); err = -EPIPE; goto errout; } if (signal_pending(current)) { err = -ERESTARTSYS; goto errout; } if (filp->f_flags & O_NONBLOCK) { err = -EAGAIN; goto errout; } interruptible_sleep_on(&PIPE_WAIT(*inode)); } PIPE_LOCK(*inode)++; while (count>0 && (free = PIPE_FREE(*inode))) { chars = PIPE_MAX_WCHUNK(*inode); if (chars > count) chars = count; if (chars > free) chars = free; pipebuf = PIPE_BASE(*inode)+PIPE_END(*inode); written += chars; PIPE_LEN(*inode) += chars; count -= chars; copy_from_user(pipebuf, buf, chars ); buf += chars; } PIPE_LOCK(*inode)--; wake_up_interruptible(&PIPE_WAIT(*inode)); free = 1; } inode->i_ctime = inode->i_mtime = CURRENT_TIME; mark_inode_dirty(inode); errout: up(&inode->i_atomic_write); down(&inode->i_sem); return written ? written : err; }
int do_pipe(int *fd) { 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; inode = get_pipe_inode(); if (!inode) goto close_f12; 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; f1->f_dentry = f2->f_dentry = dget(d_alloc_root(inode, NULL)); if (!f1->f_dentry) goto close_f12_inode_i_j; /* read file */ f1->f_pos = f2->f_pos = 0; f1->f_flags = O_RDONLY; f1->f_op = &read_pipe_fops; f1->f_mode = 1; /* write file */ f2->f_flags = O_WRONLY; f2->f_op = &write_pipe_fops; f2->f_mode = 2; fd_install(i, f1); fd_install(j, f2); fd[0] = i; fd[1] = j; return 0; close_f12_inode_i_j: put_unused_fd(j); close_f12_inode_i: put_unused_fd(i); close_f12_inode: free_page((unsigned long) PIPE_BASE(*inode)); iput(inode); close_f12: put_filp(f2); close_f1: put_filp(f1); no_files: return error; }
static int fifo_open(struct inode * inode,struct file * filp) { int retval = 0; unsigned long page; switch( filp->f_mode ) { case 1: /* * 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 = &connecting_fifo_fops; if (!PIPE_READERS(*inode)++) wake_up_interruptible(&PIPE_WAIT(*inode)); if (!(filp->f_flags & O_NONBLOCK) && !PIPE_WRITERS(*inode)) { PIPE_RD_OPENERS(*inode)++; while (!PIPE_WRITERS(*inode)) { if (current->signal & ~current->blocked) { retval = -ERESTARTSYS; break; } interruptible_sleep_on(&PIPE_WAIT(*inode)); } if (!--PIPE_RD_OPENERS(*inode)) wake_up_interruptible(&PIPE_WAIT(*inode)); } while (PIPE_WR_OPENERS(*inode)) interruptible_sleep_on(&PIPE_WAIT(*inode)); if (PIPE_WRITERS(*inode)) filp->f_op = &read_fifo_fops; if (retval && !--PIPE_READERS(*inode)) wake_up_interruptible(&PIPE_WAIT(*inode)); break; case 2: /* * O_WRONLY * POSIX.1 says that O_NONBLOCK means return -1 with * errno=ENXIO when there is no process reading the FIFO. */ if ((filp->f_flags & O_NONBLOCK) && !PIPE_READERS(*inode)) { retval = -ENXIO; break; } filp->f_op = &write_fifo_fops; if (!PIPE_WRITERS(*inode)++) wake_up_interruptible(&PIPE_WAIT(*inode)); if (!PIPE_READERS(*inode)) { PIPE_WR_OPENERS(*inode)++; while (!PIPE_READERS(*inode)) { if (current->signal & ~current->blocked) { retval = -ERESTARTSYS; break; } interruptible_sleep_on(&PIPE_WAIT(*inode)); } if (!--PIPE_WR_OPENERS(*inode)) wake_up_interruptible(&PIPE_WAIT(*inode)); } while (PIPE_RD_OPENERS(*inode)) interruptible_sleep_on(&PIPE_WAIT(*inode)); if (retval && !--PIPE_WRITERS(*inode)) wake_up_interruptible(&PIPE_WAIT(*inode)); break; case 3: /* * 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_fifo_fops; if (!PIPE_READERS(*inode)++) wake_up_interruptible(&PIPE_WAIT(*inode)); while (PIPE_WR_OPENERS(*inode)) interruptible_sleep_on(&PIPE_WAIT(*inode)); if (!PIPE_WRITERS(*inode)++) wake_up_interruptible(&PIPE_WAIT(*inode)); while (PIPE_RD_OPENERS(*inode)) interruptible_sleep_on(&PIPE_WAIT(*inode)); break; default: retval = -EINVAL; } if (retval || PIPE_BASE(*inode)) return retval; page = __get_free_page(GFP_KERNEL); if (PIPE_BASE(*inode)) { free_page(page); return 0; } if (!page) return -ENOMEM; PIPE_LOCK(*inode) = 0; PIPE_START(*inode) = PIPE_LEN(*inode) = 0; PIPE_BASE(*inode) = (char *) page; return 0; }