From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52851) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fVMSf-0001pF-UW for qemu-devel@nongnu.org; Tue, 19 Jun 2018 15:38:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fVMSe-00033R-Gn for qemu-devel@nongnu.org; Tue, 19 Jun 2018 15:38:41 -0400 Received: from mail-qt0-x22b.google.com ([2607:f8b0:400d:c0d::22b]:45390) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1fVMSe-00032r-BH for qemu-devel@nongnu.org; Tue, 19 Jun 2018 15:38:40 -0400 Received: by mail-qt0-x22b.google.com with SMTP id i18-v6so851829qtp.12 for ; Tue, 19 Jun 2018 12:38:40 -0700 (PDT) From: Daniel Henrique Barboza Date: Tue, 19 Jun 2018 16:38:04 -0300 Message-Id: <20180619193806.17419-5-danielhb413@gmail.com> In-Reply-To: <20180619193806.17419-1-danielhb413@gmail.com> References: <20180619193806.17419-1-danielhb413@gmail.com> Subject: [Qemu-devel] [PATCH v1 4/6] qga: removing switch statements, adding run_process_child List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: armbru@redhat.com, mdroth@linux.vnet.ibm.com, Daniel Henrique Barboza This is a cleanup of the resulting code after detaching pmutils and Linux sys state file logic: - remove the SUSPEND_MODE_* macros and use an enumeration instead. At the same time, drop the switch statements at the start of each function and use the enumeration index to get the right binary/argument; - create a new function called run_process_child(). This function creates a child process and executes a (shell) command, returning the command return code. This is a common operation in the pmutils functions and will be used in the systemd implementation as well, so this function will avoid code repetition. There are more places inside commands-posix.c where this new run_process_child function can also be used, but one step at a time. Signed-off-by: Daniel Henrique Barboza --- qga/commands-posix.c | 190 +++++++++++++++++-------------------------- 1 file changed, 76 insertions(+), 114 deletions(-) diff --git a/qga/commands-posix.c b/qga/commands-posix.c index a2870f9ab9..d5e3805ce9 100644 --- a/qga/commands-posix.c +++ b/qga/commands-posix.c @@ -1438,152 +1438,122 @@ qmp_guest_fstrim(bool has_minimum, int64_t minimum, Error **errp) #define LINUX_SYS_STATE_FILE "/sys/power/state" #define SUSPEND_SUPPORTED 0 #define SUSPEND_NOT_SUPPORTED 1 -#define SUSPEND_MODE_DISK 1 -#define SUSPEND_MODE_RAM 2 -#define SUSPEND_MODE_HYBRID 3 -static bool pmutils_supports_mode(int suspend_mode, Error **errp) +typedef enum { + SUSPEND_MODE_DISK = 0, + SUSPEND_MODE_RAM = 1, + SUSPEND_MODE_HYBRID = 2, +} SuspendMode; + +static int run_process_child(const char *command[], Error **errp) { Error *local_err = NULL; - const char *pmutils_arg; - const char *pmutils_bin = "pm-is-supported"; - char *pmutils_path; + char *cmd_path = g_find_program_in_path(command[0]); pid_t pid; - int status; - bool ret = false; - - switch (suspend_mode) { - - case SUSPEND_MODE_DISK: - pmutils_arg = "--hibernate"; - break; - case SUSPEND_MODE_RAM: - pmutils_arg = "--suspend"; - break; - case SUSPEND_MODE_HYBRID: - pmutils_arg = "--suspend-hybrid"; - break; - default: - return ret; - } + int status, ret = -1; - pmutils_path = g_find_program_in_path(pmutils_bin); - if (!pmutils_path) { + if (!cmd_path) { return ret; } pid = fork(); if (!pid) { setsid(); - execle(pmutils_path, pmutils_bin, pmutils_arg, NULL, environ); /* - * If we get here execle() has failed. + * execve receives a char* const argv[] as second arg but we're + * receiving a const char*[]. Since execve does not change the + * array contents it's tolerable to cast here. */ - _exit(SUSPEND_NOT_SUPPORTED); + execve(cmd_path, (char* const*)command, environ); + _exit(errno); } else if (pid < 0) { error_setg_errno(errp, errno, "failed to create child process"); + ret = EXIT_FAILURE; goto out; } ga_wait_child(pid, &status, &local_err); if (local_err) { error_propagate(errp, local_err); + ret = EXIT_FAILURE; goto out; } - switch (WEXITSTATUS(status)) { - case SUSPEND_SUPPORTED: - ret = true; - goto out; - case SUSPEND_NOT_SUPPORTED: - goto out; - default: - error_setg(errp, - "the helper program '%s' returned an unexpected exit status" - " code (%d)", pmutils_path, WEXITSTATUS(status)); - goto out; - } + ret = WEXITSTATUS(status); out: - g_free(pmutils_path); + g_free(cmd_path); return ret; } -static void pmutils_suspend(int suspend_mode, Error **errp) +static bool pmutils_supports_mode(SuspendMode mode, Error **errp) { Error *local_err = NULL; - const char *pmutils_bin; - char *pmutils_path; - pid_t pid; + const char *pmutils_args[3] = {"--hibernate", "--suspend", + "--suspend-hybrid"}; + const char *cmd[3] = {"pm-is-supported", pmutils_args[mode], NULL}; int status; - switch (suspend_mode) { - - case SUSPEND_MODE_DISK: - pmutils_bin = "pm-hibernate"; - break; - case SUSPEND_MODE_RAM: - pmutils_bin = "pm-suspend"; - break; - case SUSPEND_MODE_HYBRID: - pmutils_bin = "pm-suspend-hybrid"; - break; - default: - error_setg(errp, "unknown guest suspend mode"); - return; - } + status = run_process_child(cmd, &local_err); - pmutils_path = g_find_program_in_path(pmutils_bin); - if (!pmutils_path) { - error_setg(errp, "the helper program '%s' was not found", pmutils_bin); - return; + if (status == SUSPEND_SUPPORTED) { + return true; } - pid = fork(); - if (!pid) { - setsid(); - execle(pmutils_path, pmutils_bin, NULL, environ); - /* - * If we get here execle() has failed. - */ - _exit(EXIT_FAILURE); - } else if (pid < 0) { - error_setg_errno(errp, errno, "failed to create child process"); - goto out; + if (status == -1) { + return false; } - ga_wait_child(pid, &status, &local_err); if (local_err) { error_propagate(errp, local_err); - goto out; + } else { + error_setg(errp, + "the helper program '%s' returned an unexpected exit" + " status code (%d)", "pm-is-supported", status); } - if (WEXITSTATUS(status)) { - error_setg(errp, - "the helper program '%s' returned an unexpected exit status" - " code (%d)", pmutils_path, WEXITSTATUS(status)); + return false; +} + +static void pmutils_suspend(SuspendMode mode, Error **errp) +{ + Error *local_err = NULL; + const char *pmutils_binaries[3] = {"pm-hibernate", "pm-suspend", + "pm-suspend-hybrid"}; + const char *cmd[2] = {pmutils_binaries[mode], NULL}; + int status; + + status = run_process_child(cmd, &local_err); + + if (status == 0) { + return; } -out: - g_free(pmutils_path); + if (status == -1) { + error_setg(errp, "the helper program '%s' was not found", + pmutils_binaries[mode]); + return; + } + + if (local_err) { + error_propagate(errp, local_err); + } else { + error_setg(errp, + "the helper program '%s' returned an unexpected exit" + " status code (%d)", pmutils_binaries[mode], status); + } } -static bool linux_sys_state_supports_mode(int suspend_mode, Error **errp) +static bool linux_sys_state_supports_mode(SuspendMode mode, Error **errp) { - const char *sysfile_str; + const char *sysfile_strs[3] = {"disk", "mem", NULL}; + const char *sysfile_str = sysfile_strs[mode]; char buf[32]; /* hopefully big enough */ int fd; ssize_t ret; - switch (suspend_mode) { - - case SUSPEND_MODE_DISK: - sysfile_str = "disk"; - break; - case SUSPEND_MODE_RAM: - sysfile_str = "mem"; - break; - default: + if (!sysfile_str) { + error_setg(errp, "unknown guest suspend mode"); return false; } @@ -1604,22 +1574,15 @@ static bool linux_sys_state_supports_mode(int suspend_mode, Error **errp) return false; } -static void linux_sys_state_suspend(int suspend_mode, Error **errp) +static void linux_sys_state_suspend(SuspendMode mode, Error **errp) { Error *local_err = NULL; - const char *sysfile_str; + const char *sysfile_strs[3] = {"disk", "mem", NULL}; + const char *sysfile_str = sysfile_strs[mode]; pid_t pid; int status; - switch (suspend_mode) { - - case SUSPEND_MODE_DISK: - sysfile_str = "disk"; - break; - case SUSPEND_MODE_RAM: - sysfile_str = "mem"; - break; - default: + if (!sysfile_str) { error_setg(errp, "unknown guest suspend mode"); return; } @@ -1661,12 +1624,12 @@ static void linux_sys_state_suspend(int suspend_mode, Error **errp) } -static void bios_supports_mode(int suspend_mode, Error **errp) +static void bios_supports_mode(SuspendMode mode, Error **errp) { Error *local_err = NULL; bool ret; - ret = pmutils_supports_mode(suspend_mode, &local_err); + ret = pmutils_supports_mode(mode, &local_err); if (ret) { return; } @@ -1674,32 +1637,31 @@ static void bios_supports_mode(int suspend_mode, Error **errp) error_propagate(errp, local_err); return; } - ret = linux_sys_state_supports_mode(suspend_mode, errp); + ret = linux_sys_state_supports_mode(mode, &local_err); if (!ret) { error_setg(errp, "the requested suspend mode is not supported by the guest"); - return; } } -static void guest_suspend(int suspend_mode, Error **errp) +static void guest_suspend(SuspendMode mode, Error **errp) { Error *local_err = NULL; - bios_supports_mode(suspend_mode, &local_err); + bios_supports_mode(mode, &local_err); if (local_err) { error_propagate(errp, local_err); return; } - pmutils_suspend(suspend_mode, &local_err); + pmutils_suspend(mode, &local_err); if (!local_err) { return; } local_err = NULL; - linux_sys_state_suspend(suspend_mode, &local_err); + linux_sys_state_suspend(mode, &local_err); if (local_err) { error_propagate(errp, local_err); } -- 2.17.1