From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([222.73.24.84]:32415 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1756186Ab3IEHqW (ORCPT ); Thu, 5 Sep 2013 03:46:22 -0400 Message-ID: <5228364B.2020904@cn.fujitsu.com> Date: Thu, 05 Sep 2013 15:44:11 +0800 From: Wang Shilong MIME-Version: 1.0 To: Ilya Dryomov CC: Wang Shilong , linux-btrfs@vger.kernel.org, dsterba@suse.cz, sandeen@redhat.com Subject: Re: [PATCH 18/20] Btrfs-progs: fix magic return value in cmds-balance.c References: <1378308157-4621-1-git-send-email-wangshilong1991@gmail.com> <1378308157-4621-19-git-send-email-wangshilong1991@gmail.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hi Illya, On 09/05/2013 12:26 AM, Ilya Dryomov wrote: > Hi Wang, > > Thank you for doing the grunt work, it's been a long standing todo. > See the comments below. > > On Wed, Sep 4, 2013 at 6:22 PM, Wang Shilong wrote: >> From: Wang Shilong >> >> If there is no balance in progress.resume/pause/cancel will >> return 2. For usage or syntal errors will return 1. 0 means >> operations return successfully. > This needs to be reworded (spelling, punctuation). will fix this. > >> Signed-off-by: Wang Shilong >> --- >> cmds-balance.c | 93 ++++++++++++++++++++++++++++++++++++---------------------- >> 1 file changed, 58 insertions(+), 35 deletions(-) >> >> diff --git a/cmds-balance.c b/cmds-balance.c >> index b7382ef..fd68051 100644 >> --- a/cmds-balance.c >> +++ b/cmds-balance.c >> @@ -58,7 +58,7 @@ static int parse_one_profile(const char *profile, u64 *flags) >> *flags |= BTRFS_AVAIL_ALLOC_BIT_SINGLE; >> } else { >> fprintf(stderr, "Unknown profile '%s'\n", profile); >> - return 1; >> + return -ENOENT; >> } >> >> return 0; >> @@ -68,12 +68,14 @@ static int parse_profiles(char *profiles, u64 *flags) >> { >> char *this_char; >> char *save_ptr = NULL; /* Satisfy static checkers */ >> + int ret; >> >> for (this_char = strtok_r(profiles, "|", &save_ptr); >> this_char != NULL; >> this_char = strtok_r(NULL, "|", &save_ptr)) { >> - if (parse_one_profile(this_char, flags)) >> - return 1; >> + ret = parse_one_profile(this_char, flags); >> + if (ret) >> + return ret; >> } >> >> return 0; >> @@ -86,7 +88,7 @@ static int parse_u64(const char *str, u64 *result) >> >> val = strtoull(str, &endptr, 10); >> if (*endptr) >> - return 1; >> + return -EINVAL; >> >> *result = val; >> return 0; >> @@ -95,6 +97,7 @@ static int parse_u64(const char *str, u64 *result) >> static int parse_range(const char *range, u64 *start, u64 *end) >> { >> char *dots; >> + int ret; >> >> dots = strstr(range, ".."); >> if (dots) { >> @@ -107,29 +110,31 @@ static int parse_range(const char *range, u64 *start, u64 *end) >> *end = (u64)-1; >> skipped++; >> } else { >> - if (parse_u64(rest, end)) >> - return 1; >> + ret = parse_u64(rest, end); >> + if (ret) >> + return ret; >> } >> if (dots == range) { >> *start = 0; >> skipped++; >> } else { >> + ret = parse_u64(rest, end); >> if (parse_u64(range, start)) >> - return 1; >> + return ret; >> } >> >> if (*start >= *end) { >> fprintf(stderr, "Range %llu..%llu doesn't make " >> "sense\n", (unsigned long long)*start, >> (unsigned long long)*end); >> - return 1; >> + return -EINVAL; >> } >> >> if (skipped <= 1) >> return 0; >> } >> >> - return 1; >> + return -EINVAL; >> } >> >> static int parse_filters(char *filters, struct btrfs_balance_args *args) >> @@ -137,6 +142,7 @@ static int parse_filters(char *filters, struct btrfs_balance_args *args) >> char *this_char; >> char *value; >> char *save_ptr = NULL; /* Satisfy static checkers */ >> + int ret = 0; >> >> if (!filters) >> return 0; >> @@ -150,70 +156,72 @@ static int parse_filters(char *filters, struct btrfs_balance_args *args) >> if (!value || !*value) { >> fprintf(stderr, "the profiles filter requires " >> "an argument\n"); >> - return 1; >> + return -EINVAL; >> } >> if (parse_profiles(value, &args->profiles)) { >> fprintf(stderr, "Invalid profiles argument\n"); >> - return 1; >> + return -EINVAL; >> } >> args->flags |= BTRFS_BALANCE_ARGS_PROFILES; >> } else if (!strcmp(this_char, "usage")) { >> if (!value || !*value) { >> fprintf(stderr, "the usage filter requires " >> "an argument\n"); >> - return 1; >> + return -EINVAL; >> } >> if (parse_u64(value, &args->usage) || >> args->usage > 100) { >> fprintf(stderr, "Invalid usage argument: %s\n", >> value); >> - return 1; >> + return -EINVAL; >> } >> args->flags |= BTRFS_BALANCE_ARGS_USAGE; >> } else if (!strcmp(this_char, "devid")) { >> if (!value || !*value) { >> fprintf(stderr, "the devid filter requires " >> "an argument\n"); >> - return 1; >> + return -EINVAL; >> } >> if (parse_u64(value, &args->devid) || >> args->devid == 0) { >> fprintf(stderr, "Invalid devid argument: %s\n", >> value); >> - return 1; >> + return -EINVAL; >> } >> args->flags |= BTRFS_BALANCE_ARGS_DEVID; >> } else if (!strcmp(this_char, "drange")) { >> if (!value || !*value) { >> fprintf(stderr, "the drange filter requires " >> "an argument\n"); >> - return 1; >> + return -EINVAL; >> } >> - if (parse_range(value, &args->pstart, &args->pend)) { >> + ret = parse_range(value, &args->pstart, &args->pend); >> + if (ret) { >> fprintf(stderr, "Invalid drange argument\n"); >> - return 1; >> + return ret; >> } >> args->flags |= BTRFS_BALANCE_ARGS_DRANGE; >> } else if (!strcmp(this_char, "vrange")) { >> if (!value || !*value) { >> fprintf(stderr, "the vrange filter requires " >> "an argument\n"); >> - return 1; >> + return -EINVAL; >> } >> - if (parse_range(value, &args->vstart, &args->vend)) { >> + ret = parse_range(value, &args->vstart, &args->vend); >> + if (ret) { >> fprintf(stderr, "Invalid vrange argument\n"); >> - return 1; >> + return ret; >> } >> args->flags |= BTRFS_BALANCE_ARGS_VRANGE; >> } else if (!strcmp(this_char, "convert")) { >> if (!value || !*value) { >> fprintf(stderr, "the convert option requires " >> "an argument\n"); >> - return 1; >> + return -EINVAL; >> } >> if (parse_one_profile(value, &args->target)) { >> fprintf(stderr, "Invalid convert argument\n"); >> - return 1; >> + return -EINVAL; >> } >> args->flags |= BTRFS_BALANCE_ARGS_CONVERT; >> } else if (!strcmp(this_char, "soft")) { >> @@ -221,7 +229,7 @@ static int parse_filters(char *filters, struct btrfs_balance_args *args) >> } else { >> fprintf(stderr, "Unrecognized balance option '%s'\n", >> this_char); >> - return 1; >> + return -EINVAL; >> } >> } >> > All of the above hunks are unnecessary and need to be dropped. > Returning 0/1 is not magic, and all of those are just (static) helpers The reason is that i want to make functions return value more meaningful. We should do this as much as possible. And at the last, we chose to return 1. Thanks, Wang > >> @@ -297,9 +305,10 @@ static int do_balance(const char *path, struct btrfs_ioctl_balance_args *args, >> DIR *dirstream = NULL; >> >> fd = open_file_or_dir(path, &dirstream); >> + e = errno; >> if (fd < 0) { >> fprintf(stderr, "ERROR: can't access to '%s'\n", path); >> - return 12; >> + return e; >> } >> >> ret = ioctl(fd, BTRFS_IOC_BALANCE_V2, args); > Unnecessary, do a simple 'return 1' here. You are explicitly > discarding the return value below in your patch anyway. > >> @@ -330,7 +339,7 @@ static int do_balance(const char *path, struct btrfs_ioctl_balance_args *args, >> if (e != EINPROGRESS) >> fprintf(stderr, "There may be more info in " >> "syslog - try dmesg | tail\n"); >> - ret = 19; >> + ret = 1; >> } >> } else { >> printf("Done, had to relocate %llu out of %llu chunks\n", > Ack. > >> @@ -370,6 +379,7 @@ static int cmd_balance_start(int argc, char **argv) >> int verbose = 0; >> int nofilters = 1; >> int i; >> + int ret = 0; >> >> memset(&args, 0, sizeof(args)); >> >> @@ -473,7 +483,8 @@ static int cmd_balance_start(int argc, char **argv) >> if (verbose) >> dump_ioctl_balance_args(&args); >> >> - return do_balance(argv[optind], &args, nofilters); >> + ret = do_balance(argv[optind], &args, nofilters); >> + return !!ret; >> } >> >> static const char * const cmd_balance_pause_usage[] = { > Unnecessary, needs to be dropped. The above two hunks (with the > suggested change) already make sure do_balance() returns 0/1. > >> @@ -498,7 +509,7 @@ static int cmd_balance_pause(int argc, char **argv) >> fd = open_file_or_dir(path, &dirstream); >> if (fd < 0) { >> fprintf(stderr, "ERROR: can't access to '%s'\n", path); >> - return 12; >> + return 1; >> } >> >> ret = ioctl(fd, BTRFS_IOC_BALANCE_CTL, BTRFS_BALANCE_CTL_PAUSE); >> @@ -508,7 +519,10 @@ static int cmd_balance_pause(int argc, char **argv) >> if (ret < 0) { >> fprintf(stderr, "ERROR: balance pause on '%s' failed - %s\n", >> path, (e == ENOTCONN) ? "Not running" : strerror(e)); >> - return 19; >> + if (e == ENOTCONN) >> + return 2; >> + else >> + return 1; >> } >> >> return 0; >> @@ -536,7 +550,7 @@ static int cmd_balance_cancel(int argc, char **argv) >> fd = open_file_or_dir(path, &dirstream); >> if (fd < 0) { >> fprintf(stderr, "ERROR: can't access to '%s'\n", path); >> - return 12; >> + return 1; >> } >> >> ret = ioctl(fd, BTRFS_IOC_BALANCE_CTL, BTRFS_BALANCE_CTL_CANCEL); >> @@ -546,7 +560,10 @@ static int cmd_balance_cancel(int argc, char **argv) >> if (ret < 0) { >> fprintf(stderr, "ERROR: balance cancel on '%s' failed - %s\n", >> path, (e == ENOTCONN) ? "Not in progress" : strerror(e)); >> - return 19; >> + if (e == ENOTCONN) >> + return 2; >> + else >> + return 1; >> } >> >> return 0; >> @@ -575,7 +592,7 @@ static int cmd_balance_resume(int argc, char **argv) >> fd = open_file_or_dir(path, &dirstream); >> if (fd < 0) { >> fprintf(stderr, "ERROR: can't access to '%s'\n", path); >> - return 12; >> + return 1; >> } >> >> memset(&args, 0, sizeof(args)); >> @@ -596,12 +613,15 @@ static int cmd_balance_resume(int argc, char **argv) >> "failed - %s\n", path, >> (e == ENOTCONN) ? "Not in progress" : >> "Already running"); >> - return 19; >> + if (e == ENOTCONN) >> + return 2; >> + else >> + return 1; >> } else { >> fprintf(stderr, >> "ERROR: error during balancing '%s' - %s\n" >> "There may be more info in syslog - try dmesg | tail\n", path, strerror(e)); >> - return 19; >> + return 1; >> } >> } else { >> printf("Done, had to relocate %llu out of %llu chunks\n", > Ack up to this point. > >> @@ -719,6 +739,8 @@ const struct cmd_group balance_cmd_group = { >> >> int cmd_balance(int argc, char **argv) >> { >> + int ret = 0; >> + >> if (argc == 2) { >> /* old 'btrfs filesystem balance ' syntax */ >> struct btrfs_ioctl_balance_args args; >> @@ -726,7 +748,8 @@ int cmd_balance(int argc, char **argv) >> memset(&args, 0, sizeof(args)); >> args.flags |= BTRFS_BALANCE_TYPE_MASK; >> >> - return do_balance(argv[1], &args, 1); >> + ret = do_balance(argv[1], &args, 1); >> + return !!ret; >> } >> >> return handle_command_group(&balance_cmd_group, argc, argv); > Unnecessary, needs to be dropped. See the first do_balance() call > site. > > Thanks, > > Ilya > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >