Oren
Is there a reason we hard code STDIN_FILENO during restart in usercr ?
Or can we simply use the fd passed by the caller of cr_restart() -
something like in this patch ?
Whether it is STDIN_FILENO or another fd, do_sys_restart() holds a reference
to the 'struct file' and so we should still be able to read the image even
if close_all_fds() closes the fd. Or is there a subtle reason, we stick to
STDIN_FILENO ?
Sukadev
---
src/lxc/user-cr/restart.c | 35 ++++++++++++++++++++++-------------
1 files changed, 22 insertions(+), 13 deletions(-)
diff --git a/src/lxc/user-cr/restart.c b/src/lxc/user-cr/restart.c
index 5b22948..944dbf1 100644
--- a/src/lxc/user-cr/restart.c
+++ b/src/lxc/user-cr/restart.c
@@ -169,6 +169,7 @@ static int global_child_status;
static int global_child_collected;
static int global_sent_sigint;
static struct signal_array signal_array[] = INIT_SIGNAL_ARRAY;
+static int global_input_fd = -1;
/*
* TODO: Implement an API to let callers choose if/how an interrupt be sent
@@ -403,15 +404,23 @@ int process_args(struct cr_restart_args *args)
global_ulogfd = args->ulogfd;
global_uerrfd = args->uerrfd;
+ if (args->infd < 0) {
+ ckpt_err("Invalid input fd %d\n", args->infd);
+ exit(1);
+ }
+ global_input_fd = args->infd;
+
+#if 0
/* input file descriptor (default: stdin) */
if (args->infd >= 0) {
- if (dup2(args->infd, STDIN_FILENO) < 0) {
+ if (dup2(args->infd, global_input_fd) < 0) {
ckpt_perror("dup2 input file");
exit(1);
}
- if (args->infd != STDIN_FILENO)
+ if (args->infd != global_input_fd)
close(args->infd);
}
+#endif
/* output file descriptor (default: none) */
if (args->klogfd < 0)
@@ -492,7 +501,7 @@ int cr_restart(struct cr_restart_args *args)
if (args->mnt_pty && ckpt_remount_devpts(&ctx) < 0)
exit(1);
- restart(getpid(), STDIN_FILENO, RESTART_TASKSELF, args->klogfd);
+ restart(getpid(), global_input_fd, RESTART_TASKSELF, args->klogfd);
/* reach here if restart(2) failed ! */
ckpt_perror("restart");
@@ -926,7 +935,7 @@ static int ckpt_coordinator(struct ckpt_ctx *ctx)
if (ctx->args->keep_lsm)
flags |= RESTART_KEEP_LSM;
- ret = restart(root_pid, STDIN_FILENO, flags, ctx->args->klogfd);
+ ret = restart(root_pid, global_input_fd, flags, ctx->args->klogfd);
if (ret < 0) {
ckpt_perror("restart failed");
@@ -1658,7 +1667,7 @@ static int ckpt_make_tree(struct ckpt_ctx *ctx, struct task *task)
/* on success this doesn't return */
ckpt_dbg("about to call sys_restart(), flags %#lx\n", flags);
- ret = restart(0, STDIN_FILENO, flags, CHECKPOINT_FD_NONE);
+ ret = restart(0, global_input_fd, flags, CHECKPOINT_FD_NONE);
if (ret < 0)
ckpt_perror("task restore failed");
return ret;
@@ -1857,8 +1866,8 @@ static int ckpt_fork_feeder(struct ckpt_ctx *ctx)
ctx->pipe_out = ctx->pipe_child[1];
/* feeder pipe */
close(ctx->pipe_feed[1]);
- if (ctx->pipe_feed[0] != STDIN_FILENO) {
- dup2(ctx->pipe_feed[0], STDIN_FILENO);
+ if (ctx->pipe_feed[0] != global_input_fd) {
+ dup2(ctx->pipe_feed[0], global_input_fd);
close(ctx->pipe_feed[0]);
}
@@ -1878,7 +1887,7 @@ static void ckpt_read_write_blind(struct ckpt_ctx *ctx)
int ret;
while (1) {
- ret = read(STDIN_FILENO, ctx->buf, BUFSIZE);
+ ret = read(global_input_fd, ctx->buf, BUFSIZE);
ckpt_dbg("c/r read input %d\n", ret);
if (ret == 0)
break;
@@ -1897,7 +1906,7 @@ static void ckpt_read_write_inspect(struct ckpt_ctx *ctx)
int len, ret;
while (1) {
- ret = _ckpt_read(STDIN_FILENO, &h, sizeof(h));
+ ret = _ckpt_read(global_input_fd, &h, sizeof(h));
ckpt_dbg("ret %d len %d type %d\n", ret, h.len, h.type);
if (ret == 0)
break;
@@ -1915,7 +1924,7 @@ ckpt_dbg("ret %d len %d type %d\n", ret, h.len, h.type);
h.len -= sizeof(h);
if (h.type == CKPT_HDR_ERROR) {
len = (h.len > BUFSIZE ? BUFSIZE : h.len);
- ret = read(STDIN_FILENO, ctx->buf, len);
+ ret = read(global_input_fd, ctx->buf, len);
if (ret < 0)
ckpt_abort(ctx, "error record");
errno = EIO;
@@ -1926,7 +1935,7 @@ ckpt_dbg("ret %d len %d type %d\n", ret, h.len, h.type);
while (h.len) {
len = (h.len > BUFSIZE ? BUFSIZE : h.len);
- ret = read(STDIN_FILENO, ctx->buf, len);
+ ret = read(global_input_fd, ctx->buf, len);
if (ret == 0)
ckpt_abort(ctx, "short record");
if (ret < 0)
@@ -2163,7 +2172,7 @@ static int ckpt_read_obj(struct ckpt_ctx *ctx,
{
int ret;
- ret = ckpt_read(STDIN_FILENO, h, sizeof(*h));
+ ret = ckpt_read(global_input_fd, h, sizeof(*h));
if (ret < 0)
return ret;
if (h->len < sizeof(*h) || h->len > n) {
@@ -2172,7 +2181,7 @@ static int ckpt_read_obj(struct ckpt_ctx *ctx,
}
if (h->len == sizeof(*h))
return 0;
- return ckpt_read(STDIN_FILENO, buf, h->len - sizeof(*h));
+ return ckpt_read(global_input_fd, buf, h->len - sizeof(*h));
}
static int ckpt_read_obj_type(struct ckpt_ctx *ctx, void *buf, int n, int type)
--
1.6.6.1
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