From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: References: <20200709133103.31615-1-a.fatoum@pengutronix.de> From: Ahmad Fatoum Message-ID: Date: Wed, 10 Feb 2021 10:43:52 +0100 MIME-Version: 1.0 In-Reply-To: <20200709133103.31615-1-a.fatoum@pengutronix.de> Content-Language: en-US Subject: Re: [OSS-Tools] [PATCH] barebox-state: introduce --no-lock option to avoid lock file List-Id: Pengutronix Public Open-Source-Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: oss-tools-bounces@pengutronix.de Sender: "OSS-Tools" To: oss-tools@pengutronix.de, rhi@pengutronix.de Hello, On 09.07.20 15:31, Ahmad Fatoum wrote: > barebox-state may be run in restricted contexts where /var/lock is not > yet mounted. Introduce a --no-lock option for users that guarantee by > other means that multiple instances of barebox-state won't run concurrently. Please dismiss. This patch was for running barebox-state in a systemd-generator, which didn't have /var/lock available. /run is however available that early, so I replaced this patch with Agner's lock in /run patch on my side and I no longer see a need for this to be merged. > > Signed-off-by: Ahmad Fatoum > --- > Correct operation can be verified with > $ strace barebox-state -i file.dtb --no-lock 2>&1 | grep /var/lock > --- > src/barebox-state.c | 35 +++++++++++++++++++++++------------ > 1 file changed, 23 insertions(+), 12 deletions(-) > > diff --git a/src/barebox-state.c b/src/barebox-state.c > index c7f6dee90d4a..cd56ce7192c3 100644 > --- a/src/barebox-state.c > +++ b/src/barebox-state.c > @@ -381,6 +381,7 @@ struct state *state_get(const char *name, const char *filename, bool readonly, b > enum opt { > OPT_DUMP_SHELL = UCHAR_MAX + 1, > OPT_VERSION = UCHAR_MAX + 2, > + OPT_NO_LOCK = UCHAR_MAX + 3, > }; > > static struct option long_options[] = { > @@ -391,6 +392,7 @@ static struct option long_options[] = { > {"dump", no_argument, 0, 'd' }, > {"dump-shell", no_argument, 0, OPT_DUMP_SHELL }, > {"force", no_argument, 0, 'f' }, > + {"no-lock", no_argument, 0, OPT_NO_LOCK }, > {"verbose", no_argument, 0, 'v' }, > {"quiet", no_argument, 0, 'q' }, > {"version", no_argument, 0, OPT_VERSION }, > @@ -410,6 +412,7 @@ static void usage(char *name) > "-d, --dump dump the state\n" > "--dump-shell dump the state suitable for shell sourcing\n" > "-f, --force do not check for state manipulation via the HMAC\n" > +"--no-lock do not use lock file to guard access\n" > "-v, --verbose increase verbosity\n" > "-q, --quiet decrease verbosity\n" > "--version display version\n" > @@ -447,6 +450,7 @@ int main(int argc, char *argv[]) > int pr_level = 5; > int auth = 1; > const char *dtb = NULL; > + bool use_lock_file = true; > > INIT_LIST_HEAD(&sg_list); > INIT_LIST_HEAD(&state_list.list); > @@ -478,6 +482,9 @@ int main(int argc, char *argv[]) > case 'f': > auth = 0; > break; > + case OPT_NO_LOCK: > + use_lock_file = false; > + break; > case 'd': > do_dump = 1; > break; > @@ -530,17 +537,19 @@ int main(int argc, char *argv[]) > ++nr_states; > } > > - lock_fd = open("/var/lock/barebox-state", O_CREAT | O_RDWR, 0600); > - if (lock_fd < 0) { > - pr_err("Failed to open lock-file /var/lock/barebox-state\n"); > - exit(1); > - } > + if (use_lock_file) { > + lock_fd = open("/var/lock/barebox-state", O_CREAT | O_RDWR, 0600); > + if (lock_fd < 0) { > + pr_err("Failed to open lock-file /var/lock/barebox-state\n"); > + exit(1); > + } > > - ret = flock(lock_fd, LOCK_EX); > - if (ret < 0) { > - pr_err("Failed to lock /var/lock/barebox-state: %m\n"); > - close(lock_fd); > - exit(1); > + ret = flock(lock_fd, LOCK_EX); > + if (ret < 0) { > + pr_err("Failed to lock /var/lock/barebox-state: %m\n"); > + close(lock_fd); > + exit(1); > + } > } > > list_for_each_entry(state, &state_list.list, list) { > @@ -662,8 +671,10 @@ int main(int argc, char *argv[]) > > ret = 0; > out_unlock: > - flock(lock_fd, LOCK_UN); > - close(lock_fd); > + if (use_lock_file) { > + flock(lock_fd, LOCK_UN); > + close(lock_fd); > + } > > return ret; > } > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ OSS-Tools mailing list OSS-Tools@pengutronix.de