From: Lars R. Damerow <lars@xxxxxxxxx>
This patch creates key_thread_attempt_id as a pthread key and populates it
in each new thread serving a mount attempt. This ID can be used in output logs
as an easy string to grep for, allowing admins to quickly see a mount attempt's
log entries without the messages from other attempts interleaved.
The contents of the ID are intended to be opaque, but to get a chance at
a unique value for each mount attempt, this patch does a very simple hash
computation of the thread's wait_queue_token, the pid of the requesting
process, and the key for the mount. The hash is based on the public domain
sdbm library.
Signed-off-by: Lars R. Damerow <lars@xxxxxxxxx>
Signed-off-by: Ian Kent <raven@xxxxxxxxxx>
---
CHANGELOG | 1 +
daemon/automount.c | 24 ++++++++++++++++++++++++
daemon/direct.c | 17 +++++++++++++++++
daemon/indirect.c | 17 +++++++++++++++++
include/automount.h | 6 ++++++
5 files changed, 65 insertions(+)
diff --git a/CHANGELOG b/CHANGELOG
index cf9b62c..0cd0d45 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -50,6 +50,7 @@ xx/xx/2016 autofs-5.1.3
- fix bogus check in expire_cleanup().
- delay submount exit for amd submounts.
- add the mount requestor's pid to pending_args.
+- create thread-local ID for mount attempts.
15/06/2016 autofs-5.1.2
=======================
diff --git a/daemon/automount.c b/daemon/automount.c
index 6ebe885..2b23dec 100644
--- a/daemon/automount.c
+++ b/daemon/automount.c
@@ -89,6 +89,7 @@ struct startup_cond suc = {
PTHREAD_MUTEX_INITIALIZER, PTHREAD_COND_INITIALIZER, 0, 0};
pthread_key_t key_thread_stdenv_vars;
+pthread_key_t key_thread_attempt_id = (pthread_key_t) 0L;
#define MAX_OPEN_FILES 10240
@@ -98,6 +99,17 @@ static int umount_all(struct autofs_point *ap, int force);
extern struct master *master_list;
+/* simple string hash based on public domain sdbm library */
+unsigned long sdbm_hash(const char *str, unsigned long seed)
+{
+ unsigned long hash = seed;
+ char c;
+
+ while ((c = *str++))
+ hash = c + (hash << 6) + (hash << 16) - hash;
+ return hash;
+}
+
static int is_remote_fstype(unsigned int fs_type)
{
int ret = 0;
@@ -2468,6 +2480,18 @@ int main(int argc, char *argv[])
exit(1);
}
+ status = pthread_key_create(&key_thread_attempt_id, free);
+ if (status) {
+ logerr("%s: failed to create thread data key for attempt ID!",
+ program);
+ master_kill(master_list);
+ res = write(start_pipefd[1], pst_stat, sizeof(*pst_stat));
+ close(start_pipefd[1]);
+ release_flag_file();
+ macro_free_global_table();
+ exit(1);
+ }
+
init_ioctl_ctl();
if (!alarm_start_handler()) {
diff --git a/daemon/direct.c b/daemon/direct.c
index 33faaea..6f1329b 100644
--- a/daemon/direct.c
+++ b/daemon/direct.c
@@ -1210,6 +1210,8 @@ static void *do_mount_direct(void *arg)
struct autofs_point *ap;
struct stat st;
int status, state;
+ char attempt_id_comp[20];
+ unsigned long *attempt_id;
args = (struct pending_args *) arg;
@@ -1219,6 +1221,21 @@ static void *do_mount_direct(void *arg)
ap = mt.ap;
+ attempt_id = pthread_getspecific(key_thread_attempt_id);
+ if (attempt_id == NULL) {
+ attempt_id = (unsigned long *) calloc(1, sizeof(unsigned long));
+ if (attempt_id == NULL)
+ fatal(ENOMEM);
+ snprintf(attempt_id_comp, 20, "%ld", mt.wait_queue_token);
+ *attempt_id = sdbm_hash(attempt_id_comp, 0);
+ snprintf(attempt_id_comp, 20, "%u", mt.pid);
+ *attempt_id = sdbm_hash(attempt_id_comp, *attempt_id);
+ *attempt_id = sdbm_hash(mt.name, *attempt_id);
+ status = pthread_setspecific(key_thread_attempt_id, attempt_id);
+ if (status != 0)
+ fatal(status);
+ }
+
args->signaled = 1;
status = pthread_cond_signal(&args->cond);
if (status)
diff --git a/daemon/indirect.c b/daemon/indirect.c
index 0db2749..3ed47e8 100644
--- a/daemon/indirect.c
+++ b/daemon/indirect.c
@@ -726,6 +726,8 @@ static void *do_mount_indirect(void *arg)
char buf[PATH_MAX + 1];
struct stat st;
int len, status, state;
+ char attempt_id_comp[20];
+ unsigned long *attempt_id;
args = (struct pending_args *) arg;
@@ -735,6 +737,21 @@ static void *do_mount_indirect(void *arg)
ap = mt.ap;
+ attempt_id = pthread_getspecific(key_thread_attempt_id);
+ if (attempt_id == NULL) {
+ attempt_id = (unsigned long *) calloc(1, sizeof(unsigned long));
+ if (attempt_id == NULL)
+ fatal(ENOMEM);
+ snprintf(attempt_id_comp, 20, "%ld", mt.wait_queue_token);
+ *attempt_id = sdbm_hash(attempt_id_comp, 0);
+ snprintf(attempt_id_comp, 20, "%u", mt.pid);
+ *attempt_id = sdbm_hash(attempt_id_comp, *attempt_id);
+ *attempt_id = sdbm_hash(mt.name, *attempt_id);
+ status = pthread_setspecific(key_thread_attempt_id, attempt_id);
+ if (status != 0)
+ fatal(status);
+ }
+
args->signaled = 1;
status = pthread_cond_signal(&args->cond);
if (status)
diff --git a/include/automount.h b/include/automount.h
index 58c45a9..1800c21 100644
--- a/include/automount.h
+++ b/include/automount.h
@@ -78,6 +78,8 @@ int load_autofs4_module(void);
#define NCP_SUPER_MAGIC 0x0000564CL
#define NFS_SUPER_MAGIC 0x00006969L
+#define ATTEMPT_ID_SIZE 24
+
/* This sould be enough for at least 20 host aliases */
#define HOST_ENT_BUF_SIZE 2048
@@ -243,6 +245,8 @@ const char **copy_argv(int argc, const char **argv);
int compare_argv(int argc1, const char **argv1, int argc2, const char **argv2);
int free_argv(int argc, const char **argv);
+unsigned long sdbm_hash(const char *str, unsigned long seed);
+
void dump_core(void);
int aquire_lock(void);
void release_lock(void);
@@ -503,6 +507,8 @@ struct thread_stdenv_vars {
extern pthread_key_t key_thread_stdenv_vars;
+extern pthread_key_t key_thread_attempt_id;
+
struct kernel_mod_version {
unsigned int major;
unsigned int minor;
--
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