+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0
-#ifndef NO_BCACHEFS_FS
-
-#include "bcachefs.h"
-#include "printbuf.h"
-#include "thread_with_file.h"
-
-#include <linux/anon_inodes.h>
-#include <linux/file.h>
-#include <linux/kthread.h>
-#include <linux/pagemap.h>
-#include <linux/poll.h>
-
-void bch2_thread_with_file_exit(struct thread_with_file *thr)
-{
- if (thr->task) {
- kthread_stop(thr->task);
- put_task_struct(thr->task);
- }
-}
-
-int bch2_run_thread_with_file(struct thread_with_file *thr,
- const struct file_operations *fops,
- int (*fn)(void *))
-{
- struct file *file = NULL;
- int ret, fd = -1;
- unsigned fd_flags = O_CLOEXEC;
-
- if (fops->read && fops->write)
- fd_flags |= O_RDWR;
- else if (fops->read)
- fd_flags |= O_RDONLY;
- else if (fops->write)
- fd_flags |= O_WRONLY;
-
- char name[TASK_COMM_LEN];
- get_task_comm(name, current);
-
- thr->ret = 0;
- thr->task = kthread_create(fn, thr, "%s", name);
- ret = PTR_ERR_OR_ZERO(thr->task);
- if (ret)
- return ret;
-
- ret = get_unused_fd_flags(fd_flags);
- if (ret < 0)
- goto err;
- fd = ret;
-
- file = anon_inode_getfile(name, fops, thr, fd_flags);
- ret = PTR_ERR_OR_ZERO(file);
- if (ret)
- goto err;
-
- fd_install(fd, file);
- get_task_struct(thr->task);
- wake_up_process(thr->task);
- return fd;
-err:
- if (fd >= 0)
- put_unused_fd(fd);
- if (thr->task)
- kthread_stop(thr->task);
- return ret;
-}
-
-static inline bool thread_with_stdio_has_output(struct thread_with_stdio *thr)
-{
- return thr->stdio.output_buf.pos ||
- thr->output2.nr ||
- thr->thr.done;
-}
-
-static ssize_t thread_with_stdio_read(struct file *file, char __user *buf,
- size_t len, loff_t *ppos)
-{
- struct thread_with_stdio *thr =
- container_of(file->private_data, struct thread_with_stdio, thr);
- size_t copied = 0, b;
- int ret = 0;
-
- if ((file->f_flags & O_NONBLOCK) &&
- !thread_with_stdio_has_output(thr))
- return -EAGAIN;
-
- ret = wait_event_interruptible(thr->stdio.output_wait,
- thread_with_stdio_has_output(thr));
- if (ret)
- return ret;
-
- if (thr->thr.done)
- return 0;
-
- while (len) {
- ret = darray_make_room(&thr->output2, thr->stdio.output_buf.pos);
- if (ret)
- break;
-
- spin_lock_irq(&thr->stdio.output_lock);
- b = min_t(size_t, darray_room(thr->output2), thr->stdio.output_buf.pos);
-
- memcpy(&darray_top(thr->output2), thr->stdio.output_buf.buf, b);
- memmove(thr->stdio.output_buf.buf,
- thr->stdio.output_buf.buf + b,
- thr->stdio.output_buf.pos - b);
-
- thr->output2.nr += b;
- thr->stdio.output_buf.pos -= b;
- spin_unlock_irq(&thr->stdio.output_lock);
-
- b = min(len, thr->output2.nr);
- if (!b)
- break;
-
- b -= copy_to_user(buf, thr->output2.data, b);
- if (!b) {
- ret = -EFAULT;
- break;
- }
-
- copied += b;
- buf += b;
- len -= b;
-
- memmove(thr->output2.data,
- thr->output2.data + b,
- thr->output2.nr - b);
- thr->output2.nr -= b;
- }
-
- return copied ?: ret;
-}
-
-static int thread_with_stdio_release(struct inode *inode, struct file *file)
-{
- struct thread_with_stdio *thr =
- container_of(file->private_data, struct thread_with_stdio, thr);
-
- bch2_thread_with_file_exit(&thr->thr);
- printbuf_exit(&thr->stdio.input_buf);
- printbuf_exit(&thr->stdio.output_buf);
- darray_exit(&thr->output2);
- thr->exit(thr);
- return 0;
-}
-
-#define WRITE_BUFFER 4096
-
-static inline bool thread_with_stdio_has_input_space(struct thread_with_stdio *thr)
-{
- return thr->stdio.input_buf.pos < WRITE_BUFFER || thr->thr.done;
-}
-
-static ssize_t thread_with_stdio_write(struct file *file, const char __user *ubuf,
- size_t len, loff_t *ppos)
-{
- struct thread_with_stdio *thr =
- container_of(file->private_data, struct thread_with_stdio, thr);
- struct printbuf *buf = &thr->stdio.input_buf;
- size_t copied = 0;
- ssize_t ret = 0;
-
- while (len) {
- if (thr->thr.done) {
- ret = -EPIPE;
- break;
- }
-
- size_t b = len - fault_in_readable(ubuf, len);
- if (!b) {
- ret = -EFAULT;
- break;
- }
-
- spin_lock(&thr->stdio.input_lock);
- if (buf->pos < WRITE_BUFFER)
- bch2_printbuf_make_room(buf, min(b, WRITE_BUFFER - buf->pos));
- b = min(len, printbuf_remaining_size(buf));
-
- if (b && !copy_from_user_nofault(&buf->buf[buf->pos], ubuf, b)) {
- ubuf += b;
- len -= b;
- copied += b;
- buf->pos += b;
- }
- spin_unlock(&thr->stdio.input_lock);
-
- if (b) {
- wake_up(&thr->stdio.input_wait);
- } else {
- if ((file->f_flags & O_NONBLOCK)) {
- ret = -EAGAIN;
- break;
- }
-
- ret = wait_event_interruptible(thr->stdio.input_wait,
- thread_with_stdio_has_input_space(thr));
- if (ret)
- break;
- }
- }
-
- return copied ?: ret;
-}
-
-static __poll_t thread_with_stdio_poll(struct file *file, struct poll_table_struct *wait)
-{
- struct thread_with_stdio *thr =
- container_of(file->private_data, struct thread_with_stdio, thr);
-
- poll_wait(file, &thr->stdio.output_wait, wait);
- poll_wait(file, &thr->stdio.input_wait, wait);
-
- __poll_t mask = 0;
-
- if (thread_with_stdio_has_output(thr))
- mask |= EPOLLIN;
- if (thread_with_stdio_has_input_space(thr))
- mask |= EPOLLOUT;
- if (thr->thr.done)
- mask |= EPOLLHUP|EPOLLERR;
- return mask;
-}
-
-static const struct file_operations thread_with_stdio_fops = {
- .release = thread_with_stdio_release,
- .read = thread_with_stdio_read,
- .write = thread_with_stdio_write,
- .poll = thread_with_stdio_poll,
- .llseek = no_llseek,
-};
-
-int bch2_run_thread_with_stdio(struct thread_with_stdio *thr,
- void (*exit)(struct thread_with_stdio *),
- int (*fn)(void *))
-{
- thr->stdio.input_buf = PRINTBUF;
- thr->stdio.input_buf.atomic++;
- spin_lock_init(&thr->stdio.input_lock);
- init_waitqueue_head(&thr->stdio.input_wait);
-
- thr->stdio.output_buf = PRINTBUF;
- thr->stdio.output_buf.atomic++;
- spin_lock_init(&thr->stdio.output_lock);
- init_waitqueue_head(&thr->stdio.output_wait);
-
- darray_init(&thr->output2);
- thr->exit = exit;
-
- return bch2_run_thread_with_file(&thr->thr, &thread_with_stdio_fops, fn);
-}
-
-int bch2_stdio_redirect_read(struct stdio_redirect *stdio, char *buf, size_t len)
-{
- wait_event(stdio->input_wait,
- stdio->input_buf.pos || stdio->done);
-
- if (stdio->done)
- return -1;
-
- spin_lock(&stdio->input_lock);
- int ret = min(len, stdio->input_buf.pos);
- stdio->input_buf.pos -= ret;
- memcpy(buf, stdio->input_buf.buf, ret);
- memmove(stdio->input_buf.buf,
- stdio->input_buf.buf + ret,
- stdio->input_buf.pos);
- spin_unlock(&stdio->input_lock);
-
- wake_up(&stdio->input_wait);
- return ret;
-}
-
-int bch2_stdio_redirect_readline(struct stdio_redirect *stdio, char *buf, size_t len)
-{
- wait_event(stdio->input_wait,
- stdio->input_buf.pos || stdio->done);
-
- if (stdio->done)
- return -1;
-
- spin_lock(&stdio->input_lock);
- int ret = min(len, stdio->input_buf.pos);
- char *n = memchr(stdio->input_buf.buf, '\n', ret);
- if (n)
- ret = min(ret, n + 1 - stdio->input_buf.buf);
- stdio->input_buf.pos -= ret;
- memcpy(buf, stdio->input_buf.buf, ret);
- memmove(stdio->input_buf.buf,
- stdio->input_buf.buf + ret,
- stdio->input_buf.pos);
- spin_unlock(&stdio->input_lock);
-
- wake_up(&stdio->input_wait);
- return ret;
-}
-
-#endif /* NO_BCACHEFS_FS */
projects / bcachefs-tools-debian / blobdiff