From 8c6157b6b30a765ec233a1be5f9446f24a5283de Mon Sep 17 00:00:00 2001 From: Anton Ivanov Date: Mon, 21 Dec 2015 18:54:00 +0000 Subject: um: Update UBD to use pread/pwrite family of functions This decreases the number of syscalls per read/write by half. Signed-off-by: Anton Ivanov Signed-off-by: Richard Weinberger --- arch/um/drivers/ubd_kern.c | 27 +++++---------------------- 1 file changed, 5 insertions(+), 22 deletions(-) (limited to 'arch/um/drivers/ubd_kern.c') diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index e8ab93c3e638..39ba20755e03 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -535,11 +535,7 @@ static int read_cow_bitmap(int fd, void *buf, int offset, int len) { int err; - err = os_seek_file(fd, offset); - if (err < 0) - return err; - - err = os_read_file(fd, buf, len); + err = os_pread_file(fd, buf, len, offset); if (err < 0) return err; @@ -1377,14 +1373,8 @@ static int update_bitmap(struct io_thread_req *req) if(req->cow_offset == -1) return 0; - n = os_seek_file(req->fds[1], req->cow_offset); - if(n < 0){ - printk("do_io - bitmap lseek failed : err = %d\n", -n); - return 1; - } - - n = os_write_file(req->fds[1], &req->bitmap_words, - sizeof(req->bitmap_words)); + 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]); @@ -1399,7 +1389,6 @@ static void do_io(struct io_thread_req *req) char *buf; unsigned long len; int n, nsectors, start, end, bit; - int err; __u64 off; if (req->op == UBD_FLUSH) { @@ -1428,18 +1417,12 @@ static void do_io(struct io_thread_req *req) len = (end - start) * req->sectorsize; buf = &req->buffer[start * req->sectorsize]; - err = os_seek_file(req->fds[bit], off); - if(err < 0){ - printk("do_io - lseek failed : err = %d\n", -err); - req->error = 1; - return; - } if(req->op == UBD_READ){ n = 0; do { buf = &buf[n]; len -= n; - n = os_read_file(req->fds[bit], buf, len); + 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]); @@ -1449,7 +1432,7 @@ static void do_io(struct io_thread_req *req) } while((n < len) && (n != 0)); if (n < len) memset(&buf[n], 0, len - n); } else { - n = os_write_file(req->fds[bit], buf, len); + 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]); -- cgit v1.2.3