diff options
Diffstat (limited to 'arch/um/drivers/ubd_kern.c')
| -rw-r--r-- | arch/um/drivers/ubd_kern.c | 42 |
1 files changed, 17 insertions, 25 deletions
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index 58860ef6931a..1672e3c49bfb 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -1,4 +1,5 @@ /* + * Copyright (C) 2018 Cambridge Greys Ltd * Copyright (C) 2015-2016 Anton Ivanov (aivanov@brocade.com) * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) * Licensed under the GPL @@ -1440,6 +1441,19 @@ static int map_error(int error_code) return BLK_STS_IOERR; } +/* + * Everything from here onwards *IS NOT PART OF THE KERNEL* + * + * The following functions are part of UML hypervisor code. + * All functions from here onwards are executed as a helper + * thread and are not allowed to execute any kernel functions. + * + * Any communication must occur strictly via shared memory and IPC. + * + * Do not add printks, locks, kernel memory operations, etc - it + * will result in unpredictable behaviour and/or crashes. + */ + static int update_bitmap(struct io_thread_req *req) { int n; @@ -1449,11 +1463,8 @@ static int update_bitmap(struct io_thread_req *req) n = os_pwrite_file(req->fds[1], &req->bitmap_words, sizeof(req->bitmap_words), req->cow_offset); - if(n != sizeof(req->bitmap_words)){ - printk("do_io - bitmap update failed, err = %d fd = %d\n", -n, - req->fds[1]); + if(n != sizeof(req->bitmap_words)) return map_error(-n); - } return map_error(0); } @@ -1467,12 +1478,7 @@ static void do_io(struct io_thread_req *req) if (req_op(req->req) == REQ_OP_FLUSH) { /* fds[0] is always either the rw image or our cow file */ - n = os_sync_file(req->fds[0]); - if (n != 0) { - printk("do_io - sync failed err = %d " - "fd = %d\n", -n, req->fds[0]); - req->error = map_error(-n); - } + req->error = map_error(-os_sync_file(req->fds[0])); return; } @@ -1497,9 +1503,7 @@ static void do_io(struct io_thread_req *req) buf = &buf[n]; len -= n; n = os_pread_file(req->fds[bit], buf, len, off); - if (n < 0) { - printk("do_io - read failed, err = %d " - "fd = %d\n", -n, req->fds[bit]); + if(n < 0){ req->error = map_error(-n); return; } @@ -1508,8 +1512,6 @@ static void do_io(struct io_thread_req *req) } else { n = os_pwrite_file(req->fds[bit], buf, len, off); if(n != len){ - printk("do_io - write failed err = %d " - "fd = %d\n", -n, req->fds[bit]); req->error = map_error(-n); return; } @@ -1547,11 +1549,6 @@ int io_thread(void *arg) if (n == -EAGAIN) { ubd_read_poll(-1); continue; - } else { - printk("io_thread - read failed, fd = %d, " - "err = %d," - "reminder = %d\n", - kernel_fd, -n, io_remainder_size); } } @@ -1566,11 +1563,6 @@ int io_thread(void *arg) res = os_write_file(kernel_fd, ((char *) io_req_buffer) + written, n); if (res >= 0) { written += res; - } else { - if (res != -EAGAIN) { - printk("io_thread - write failed, fd = %d, " - "err = %d\n", kernel_fd, -n); - } } if (written < n) { ubd_write_poll(-1); |