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uffd: Introduce lazy_pages_fd as preparation for socket polling

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We will want to poll not only a bunch of uffd-s, but also the lazy
socket, so here's "an fd and a callback" object to be pushed into
epoll.

travis-ci: success for uffd: A new set of improvements
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
This commit is contained in:
Pavel Emelyanov
2016-11-15 18:57:12 +02:00
committed by Andrei Vagin
parent 700419bc7e
commit 7c6f72cf4d
1 changed files with 31 additions and 18 deletions
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49
criu/uffd.c
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@@ -53,9 +53,13 @@ struct lazy_iovec {
unsigned long len;
};
struct lazy_pages_fd {
int fd;
int (*event)(struct lazy_pages_fd *, void *dest);
};
struct lazy_pages_info {
int pid;
int uffd;
struct list_head iovs;
@@ -64,10 +68,13 @@ struct lazy_pages_info {
unsigned long total_pages;
unsigned long copied_pages;
struct lazy_pages_fd lpfd;
struct list_head l;
};
static LIST_HEAD(lpis);
static int handle_user_fault(struct lazy_pages_fd *lpfd, void *dest);
static struct lazy_pages_info *lpi_init(void)
{
@@ -80,6 +87,7 @@ static struct lazy_pages_info *lpi_init(void)
memset(lpi, 0, sizeof(*lpi));
INIT_LIST_HEAD(&lpi->iovs);
INIT_LIST_HEAD(&lpi->l);
lpi->lpfd.event = handle_user_fault;
return lpi;
}
@@ -92,8 +100,8 @@ static void lpi_fini(struct lazy_pages_info *lpi)
return;
list_for_each_entry_safe(p, n, &lpi->iovs, l)
xfree(p);
if (lpi->uffd > 0)
close(lpi->uffd);
if (lpi->lpfd.fd > 0)
close(lpi->lpfd.fd);
if (lpi->pr.close)
lpi->pr.close(&lpi->pr);
free(lpi);
@@ -457,15 +465,15 @@ static int ud_open(int client, struct lazy_pages_info **_lpi)
return 0;
}
lpi->uffd = recv_fd(client);
if (lpi->uffd < 0) {
lpi->lpfd.fd = recv_fd(client);
if (lpi->lpfd.fd < 0) {
pr_err("recv_fd error\n");
goto out;
}
pr_debug("lpi->uffd %d\n", lpi->uffd);
pr_debug("lpi->uffd %d\n", lpi->lpfd.fd);
pr_debug("uffd is 0x%d\n", lpi->uffd);
uffd_flags = fcntl(lpi->uffd, F_GETFD, NULL);
pr_debug("uffd is 0x%d\n", lpi->lpfd.fd);
uffd_flags = fcntl(lpi->lpfd.fd, F_GETFD, NULL);
pr_debug("uffd_flags are 0x%x\n", uffd_flags);
ret = open_page_read(lpi->pid, &lpi->pr, PR_TASK);
@@ -537,7 +545,7 @@ static int uffd_copy_page(struct lazy_pages_info *lpi, __u64 address,
uffdio_copy.copy = 0;
pr_debug("uffdio_copy.dst 0x%llx\n", uffdio_copy.dst);
rc = ioctl(lpi->uffd, UFFDIO_COPY, &uffdio_copy);
rc = ioctl(lpi->lpfd.fd, UFFDIO_COPY, &uffdio_copy);
pr_debug("ioctl UFFDIO_COPY rc 0x%x\n", rc);
pr_debug("uffdio_copy.copy 0x%llx\n", uffdio_copy.copy);
if (rc) {
@@ -568,7 +576,7 @@ static int uffd_zero_page(struct lazy_pages_info *lpi, __u64 address)
uffdio_zeropage.mode = 0;
pr_debug("uffdio_zeropage.range.start 0x%llx\n", uffdio_zeropage.range.start);
rc = ioctl(lpi->uffd, UFFDIO_ZEROPAGE, &uffdio_zeropage);
rc = ioctl(lpi->lpfd.fd, UFFDIO_ZEROPAGE, &uffdio_zeropage);
pr_debug("ioctl UFFDIO_ZEROPAGE rc 0x%x\n", rc);
pr_debug("uffdio_zeropage.zeropage 0x%llx\n", uffdio_zeropage.zeropage);
if (rc) {
@@ -634,14 +642,17 @@ static int handle_regular_pages(struct lazy_pages_info *lpi, void *dest,
return 0;
}
static int handle_user_fault(struct lazy_pages_info *lpi, void *dest)
static int handle_user_fault(struct lazy_pages_fd *lpfd, void *dest)
{
struct lazy_pages_info *lpi;
struct uffd_msg msg;
__u64 flags;
__u64 address;
int ret;
ret = read(lpi->uffd, &msg, sizeof(msg));
lpi = container_of(lpfd, struct lazy_pages_info, lpfd);
ret = read(lpfd->fd, &msg, sizeof(msg));
pr_debug("read() ret: 0x%x\n", ret);
if (!ret)
return 1;
@@ -709,6 +720,8 @@ static int handle_requests(int epollfd, struct epoll_event *events)
return ret;
while (1) {
struct lazy_pages_fd *lpfd;
/*
* Setting the timeout to 5 seconds. If after this time
* no uffd pages are requested the code switches to
@@ -728,8 +741,8 @@ static int handle_requests(int epollfd, struct epoll_event *events)
for (i = 0; i < ret; i++) {
int err;
lpi = (struct lazy_pages_info *)events[i].data.ptr;
err = handle_user_fault(lpi, dest);
lpfd = (struct lazy_pages_fd *)events[i].data.ptr;
err = lpfd->event(lpfd, dest);
if (err < 0)
goto out;
}
@@ -789,13 +802,13 @@ free_events:
return -1;
}
static int epoll_add_lpi(int epollfd, struct lazy_pages_info *lpi)
static int epoll_add_lpfd(int epollfd, struct lazy_pages_fd *lpfd)
{
struct epoll_event ev;
ev.events = EPOLLIN;
ev.data.ptr = lpi;
if (epoll_ctl(epollfd, EPOLL_CTL_ADD, lpi->uffd, &ev) == -1) {
ev.data.ptr = lpfd;
if (epoll_ctl(epollfd, EPOLL_CTL_ADD, lpfd->fd, &ev) == -1) {
pr_perror("epoll_ctl failed");
return -1;
}
@@ -842,7 +855,7 @@ static int prepare_uffds(int listen, int epollfd)
goto close_uffd;
if (lpi == NULL)
continue;
if (epoll_add_lpi(epollfd, lpi))
if (epoll_add_lpfd(epollfd, &lpi->lpfd))
goto close_uffd;
}