From: Serge E. Hallyn <[email protected]> Move setting of ctx->errno into do_ckpt_msg(). If the operation is a restart, and errno was previously unset, then also wake all waiting callers so they know to quit.
NOTE that the way this is set up, users of _ckpt_err().._ckpt_msg_complete() do not cause restore_wake_all_on_error() to be called. If a restart path has to use _ckpt_err(), then we'll have to work around that, which seems simplest to do by again using the CKPT_CTX_WOKEN flag separate from CKPT_CTX_ERROR. Signed-off-by: Serge E. Hallyn <[email protected]> --- checkpoint/restart.c | 32 ++++---------------------------- checkpoint/sys.c | 25 +++++++++++++++++-------- include/linux/checkpoint.h | 6 ------ 3 files changed, 21 insertions(+), 42 deletions(-) diff --git a/checkpoint/restart.c b/checkpoint/restart.c index 6cdefc9..a45263e 100644 --- a/checkpoint/restart.c +++ b/checkpoint/restart.c @@ -719,29 +719,6 @@ static inline int is_task_active(struct ckpt_ctx *ctx, pid_t pid) return get_active_pid(ctx) == pid; } -/* should not be called under write_lock_irq(&tasklist_lock) */ -static void _restore_notify_error(struct ckpt_ctx *ctx, int errno) -{ - /* first to fail: notify everyone (racy but harmless) */ - if (!ckpt_test_ctx_error(ctx)) { - ckpt_debug("setting restart error %d\n", errno); \ - ckpt_set_ctx_error(ctx, errno); - complete(&ctx->complete); - wake_up_all(&ctx->waitq); - wake_up_all(&ctx->ghostq); - } -} - -/* - * Need to call ckpt_debug such that it will get the correct source - * location. Should not be called under write_lock_irq(&tasklist_lock) -*/ -#define restore_notify_error(ctx, errno) \ -do { \ - ckpt_debug("restart error %d, root pid %d\n", errno, ctx->root_pid); \ - _restore_notify_error(ctx, errno); \ -} while(0) - static inline struct ckpt_ctx *get_task_ctx(struct task_struct *task) { struct ckpt_ctx *ctx; @@ -812,8 +789,7 @@ static int restore_activate_next(struct ckpt_ctx *ctx) rcu_read_unlock(); if (!task) { - ckpt_debug("could not find task %d\n", pid); - restore_notify_error(ctx, -ESRCH); + ckpt_err(ctx, -ESRCH, "could not find task %d\n", pid); return -ESRCH; } } else { @@ -898,7 +874,7 @@ static int do_ghost_task(void) out: restore_debug_error(ctx, ret); if (ret < 0) - restore_notify_error(ctx, ret); + ckpt_err(ctx, ret, "Error while restarting ghost\n"); current->exit_signal = -1; restore_debug_exit(ctx); @@ -1009,7 +985,7 @@ static int do_restore_task(void) out: restore_debug_error(ctx, ret); if (ret < 0) - restore_notify_error(ctx, ret); + ckpt_err(ctx, ret, "Error while restarting task\n"); post_restore_task(); current->flags &= ~PF_RESTARTING; @@ -1272,7 +1248,7 @@ static int do_restore_coord(struct ckpt_ctx *ctx, pid_t pid) restore_debug_error(ctx, ret); if (ret < 0) - ckpt_set_ctx_error(ctx, ret); + ckpt_err(ctx, ret, "Error while restarting coordinator\n"); if (ckpt_test_ctx_error(ctx)) { destroy_descendants(ctx); diff --git a/checkpoint/sys.c b/checkpoint/sys.c index bf66418..f22bdb7 100644 --- a/checkpoint/sys.c +++ b/checkpoint/sys.c @@ -376,6 +376,19 @@ static inline int is_special_flag(char *s) } /* + * If exiting a restart with error, then wake up all other tasks + * in the restart context. + */ +static void restore_wake_all_on_error(struct ckpt_ctx *ctx) +{ + if (!ctx->kflags & CKPT_CTX_RESTART) + return; + complete(&ctx->complete); + wake_up_all(&ctx->waitq); + wake_up_all(&ctx->ghostq); +} + +/* * _ckpt_generate_fmt - handle the special flags in the enhanced format * strings used by checkpoint/restart error messages. * @ctx: checkpoint context @@ -459,14 +472,6 @@ static void _ckpt_msg_appendv(struct ckpt_ctx *ctx, int err, char *fmt, int len = ctx->msglen; if (err) { - /* At restart we must use a more baroque helper to set - * ctx->errno, which also wakes all other waiting restarting - * tasks. But at checkpoint we just set ctx->errno so that - * _ckpt_msg_complete() will know to write the error message - * to the checkpoint image. - */ - if (ctx->kflags & CKPT_CTX_CHECKPOINT && !ctx->errno) - ctx->errno = err; len += snprintf(&ctx->msg[len], CKPT_MSG_LEN-len, "[err %d]", err); if (len > CKPT_MSG_LEN) @@ -543,6 +548,10 @@ void do_ckpt_msg(struct ckpt_ctx *ctx, int err, char *fmt, ...) { if (!ctx) return; + if (err && !ckpt_test_and_set_ctx_kflag(ctx, CKPT_CTX_ERROR)) { + ctx->errno = err; + restore_wake_all_on_error(ctx); + } ckpt_msg_lock(ctx); __do_ckpt_msg(ctx, err, fmt); _ckpt_msg_complete(ctx); diff --git a/include/linux/checkpoint.h b/include/linux/checkpoint.h index 65765af..470097d 100644 --- a/include/linux/checkpoint.h +++ b/include/linux/checkpoint.h @@ -104,12 +104,6 @@ extern int ckpt_sock_getnames(struct ckpt_ctx *ctx, #define ckpt_set_ctx_success(ctx) ckpt_set_ctx_kflag(ctx, CKPT_CTX_SUCCESS) -static inline void ckpt_set_ctx_error(struct ckpt_ctx *ctx, int errno) -{ - if (!ckpt_test_and_set_ctx_kflag(ctx, CKPT_CTX_ERROR)) - ctx->errno = errno; -} - #define ckpt_test_ctx_error(ctx) \ ((ctx)->kflags & CKPT_CTX_ERROR) #define ckpt_test_ctx_complete(ctx) \ -- 1.6.1 _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
