On 05/04/2016 09:27 AM, Steve Dickson wrote:
> One very small nit...
>
> On 05/03/2016 10:46 AM, Olga Kornievskaia wrote:
>> This patch moves reading of the upcall information from the child thread
>> into the main thread. It removes the need to synchronize between the
>> parent and child thread before processing upcall. Also it creates the thread
>> in a detached state.
>>
>> Signed-off-by: Olga Kornievskaia <kolga@xxxxxxxxxx>
>> ---
>> utils/gssd/gssd.c | 95 +++++++++++++++++++++++++++++++++++---------------
>> utils/gssd/gssd.h | 13 +++++--
>> utils/gssd/gssd_proc.c | 73 +++++++++++---------------------------
>> 3 files changed, 98 insertions(+), 83 deletions(-)
>>
>> diff --git a/utils/gssd/gssd.c b/utils/gssd/gssd.c
>> index 9bf7917..95b6715 100644
>> --- a/utils/gssd/gssd.c
>> +++ b/utils/gssd/gssd.c
>> @@ -363,54 +363,93 @@ gssd_destroy_client(struct clnt_info *clp)
>>
>> static void gssd_scan(void);
>>
>> -static inline void
>> -wait_for_child_and_detach(pthread_t th)
>> +static void
>> +start_upcall_thread(void (*func)(struct clnt_upcall_info *), void *info)
>> +{
>> + pthread_attr_t attr;
>> + pthread_t th;
>> + int ret;
>> +
>> + ret = pthread_attr_init(&attr);
>> + if (ret != 0) {
>> + printerr(0, "ERROR: failed to init pthread attr: ret %d: %s\n",
>> + ret, strerror(errno));
>> + goto err;
>> + }
>> + ret = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
>> + if (ret != 0) {
>> + printerr(0, "ERROR: failed to create pthread attr: ret %d: "
>> + "%s\n", ret, strerror(errno));
>> + goto err;
>> + }
>> +
>> + ret = pthread_create(&th, &attr, (void *)func, (void *)info);
>> + if (ret != 0) {
>> + printerr(0, "ERROR: pthread_create failed: ret %d: %s\n",
>> + ret, strerror(errno));
>> + goto err;
>> + }
>> + return;
>> +err:
>> + free(info);
>> +}
>> +
>> +static struct clnt_upcall_info *alloc_upcall_info(struct clnt_info *clp)
>> {
>> - pthread_mutex_lock(&pmutex);
>> - while (!thread_started)
>> - pthread_cond_wait(&pcond, &pmutex);
>> - thread_started = false;
>> - pthread_mutex_unlock(&pmutex);
>> - pthread_detach(th);
>> + struct clnt_upcall_info *info;
>> +
>> + info = malloc(sizeof(struct clnt_upcall_info));
>> + if (info == NULL)
>> + return NULL;
>> + info->clp = clp;
>> +
>> + return info;
>> }
>>
>> -/* For each upcall create a thread, detach from the main process so that
>> - * resources are released back into the system without the need for a join.
>> - * We need to wait for the child thread to start and consume the event from
>> - * the file descriptor.
>> +/* For each upcall read the upcall info into the buffer, then create a
>> + * thread in a detached state so that resources are released back into
>> + * the system without the need for a join.
>> */
>> static void
>> gssd_clnt_gssd_cb(int UNUSED(fd), short UNUSED(which), void *data)
>> {
>> struct clnt_info *clp = data;
>> - pthread_t th;
>> - int ret;
>> + struct clnt_upcall_info *info;
>>
>> - ret = pthread_create(&th, NULL, (void *)handle_gssd_upcall,
>> - (void *)clp);
>> - if (ret != 0) {
>> - printerr(0, "ERROR: pthread_create failed: ret %d: %s\n",
>> - ret, strerror(errno));
>> + info = alloc_upcall_info(clp);
>> + if (info == NULL)
>> + return;
>> +
>> + info->lbuflen = read(clp->gssd_fd, info->lbuf, sizeof(info->lbuf));
>> + if (info->lbuflen <= 0 || info->lbuf[info->lbuflen-1] != '\n') {
>> + printerr(0, "WARNING: %s: failed reading request\n", __func__);
>> + free(info);
>> return;
>> }
>> - wait_for_child_and_detach(th);
>> + info->lbuf[info->lbuflen-1] = 0;
>> +
>> + start_upcall_thread(handle_gssd_upcall, info);
> Instead of having start_upcall_thread() free the info pointer
> I think it makes it more readable if gssd_clnt_gssd_cb() does the
> free... So the routine would allocate the pointer, populate the
> pointer and free the point all in one routine.
>
> I think it would make start_upcall_thread() simpler since
> it would not need all those goto...
If you are good with this... I'll make the changes... no
need to post a second versions...
steved.
>
> steved.
>
>> }
>>
>> static void
>> gssd_clnt_krb5_cb(int UNUSED(fd), short UNUSED(which), void *data)
>> {
>> struct clnt_info *clp = data;
>> - pthread_t th;
>> - int ret;
>> + struct clnt_upcall_info *info;
>>
>> - ret = pthread_create(&th, NULL, (void *)handle_krb5_upcall,
>> - (void *)clp);
>> - if (ret != 0) {
>> - printerr(0, "ERROR: pthread_create failed: ret %d: %s\n",
>> - ret, strerror(errno));
>> + info = alloc_upcall_info(clp);
>> + if (info == NULL)
>> + return;
>> +
>> + if (read(clp->krb5_fd, &info->uid,
>> + sizeof(info->uid)) < (ssize_t)sizeof(info->uid)) {
>> + printerr(0, "WARNING: %s: failed reading uid from krb5 "
>> + "upcall pipe: %s\n", __func__, strerror(errno));
>> + free(info);
>> return;
>> }
>> - wait_for_child_and_detach(th);
>> +
>> + start_upcall_thread(handle_krb5_upcall, info);
>> }
>>
>> static struct clnt_info *
>> diff --git a/utils/gssd/gssd.h b/utils/gssd/gssd.h
>> index 565bce3..f4f5975 100644
>> --- a/utils/gssd/gssd.h
>> +++ b/utils/gssd/gssd.h
>> @@ -49,7 +49,7 @@
>> #define GSSD_DEFAULT_MACHINE_CRED_SUFFIX "machine"
>> #define GSSD_DEFAULT_KEYTAB_FILE "/etc/krb5.keytab"
>> #define GSSD_SERVICE_NAME "nfs"
>> -
>> +#define RPC_CHAN_BUF_SIZE 32768
>> /*
>> * The gss mechanisms that we can handle
>> */
>> @@ -85,8 +85,15 @@ struct clnt_info {
>> struct sockaddr_storage addr;
>> };
>>
>> -void handle_krb5_upcall(struct clnt_info *clp);
>> -void handle_gssd_upcall(struct clnt_info *clp);
>> +struct clnt_upcall_info {
>> + struct clnt_info *clp;
>> + char lbuf[RPC_CHAN_BUF_SIZE];
>> + int lbuflen;
>> + uid_t uid;
>> +};
>> +
>> +void handle_krb5_upcall(struct clnt_upcall_info *clp);
>> +void handle_gssd_upcall(struct clnt_upcall_info *clp);
>>
>>
>> #endif /* _RPC_GSSD_H_ */
>> diff --git a/utils/gssd/gssd_proc.c b/utils/gssd/gssd_proc.c
>> index afaaf9e..d74d372 100644
>> --- a/utils/gssd/gssd_proc.c
>> +++ b/utils/gssd/gssd_proc.c
>> @@ -79,7 +79,6 @@
>> #include "nfsrpc.h"
>> #include "nfslib.h"
>> #include "gss_names.h"
>> -#include "misc.h"
>>
>> /* Encryption types supported by the kernel rpcsec_gss code */
>> int num_krb5_enctypes = 0;
>> @@ -708,45 +707,22 @@ out_return_error:
>> goto out;
>> }
>>
>> -/* signal to the parent thread that we have read from the file descriptor.
>> - * it should allow the parent to proceed to poll on the descriptor for
>> - * the next upcall from the kernel.
>> - */
>> -static inline void
>> -signal_parent_event_consumed(void)
>> -{
>> - pthread_mutex_lock(&pmutex);
>> - thread_started = true;
>> - pthread_cond_signal(&pcond);
>> - pthread_mutex_unlock(&pmutex);
>> -}
>> -
>> void
>> -handle_krb5_upcall(struct clnt_info *clp)
>> +handle_krb5_upcall(struct clnt_upcall_info *info)
>> {
>> - uid_t uid;
>> - int status;
>> + struct clnt_info *clp = info->clp;
>>
>> - status = read(clp->krb5_fd, &uid, sizeof(uid)) < (ssize_t)sizeof(uid);
>> - signal_parent_event_consumed();
>> + printerr(2, "\n%s: uid %d (%s)\n", __func__, info->uid, clp->relpath);
>>
>> - if (status) {
>> - printerr(0, "WARNING: failed reading uid from krb5 "
>> - "upcall pipe: %s\n", strerror(errno));
>> - return;
>> - }
>> -
>> - printerr(2, "\n%s: uid %d (%s)\n", __func__, uid, clp->relpath);
>> -
>> - process_krb5_upcall(clp, uid, clp->krb5_fd, NULL, NULL);
>> + process_krb5_upcall(clp, info->uid, clp->krb5_fd, NULL, NULL);
>> + free(info);
>> }
>>
>> void
>> -handle_gssd_upcall(struct clnt_info *clp)
>> +handle_gssd_upcall(struct clnt_upcall_info *info)
>> {
>> + struct clnt_info *clp = info->clp;
>> uid_t uid;
>> - char lbuf[RPC_CHAN_BUF_SIZE];
>> - int lbuflen = 0;
>> char *p;
>> char *mech = NULL;
>> char *uidstr = NULL;
>> @@ -754,19 +730,9 @@ handle_gssd_upcall(struct clnt_info *clp)
>> char *service = NULL;
>> char *enctypes = NULL;
>>
>> - lbuflen = read(clp->gssd_fd, lbuf, sizeof(lbuf));
>> - signal_parent_event_consumed();
>> + printerr(2, "\n%s: '%s' (%s)\n", __func__, info->lbuf, clp->relpath);
>>
>> - if (lbuflen <= 0 || lbuf[lbuflen-1] != '\n') {
>> - printerr(0, "WARNING: handle_gssd_upcall: "
>> - "failed reading request\n");
>> - return;
>> - }
>> - lbuf[lbuflen-1] = 0;
>> -
>> - printerr(2, "\n%s: '%s' (%s)\n", __func__, lbuf, clp->relpath);
>> -
>> - for (p = strtok(lbuf, " "); p; p = strtok(NULL, " ")) {
>> + for (p = strtok(info->lbuf, " "); p; p = strtok(NULL, " ")) {
>> if (!strncmp(p, "mech=", strlen("mech=")))
>> mech = p + strlen("mech=");
>> else if (!strncmp(p, "uid=", strlen("uid=")))
>> @@ -782,8 +748,8 @@ handle_gssd_upcall(struct clnt_info *clp)
>> if (!mech || strlen(mech) < 1) {
>> printerr(0, "WARNING: handle_gssd_upcall: "
>> "failed to find gss mechanism name "
>> - "in upcall string '%s'\n", lbuf);
>> - return;
>> + "in upcall string '%s'\n", info->lbuf);
>> + goto out;
>> }
>>
>> if (uidstr) {
>> @@ -795,21 +761,21 @@ handle_gssd_upcall(struct clnt_info *clp)
>> if (!uidstr) {
>> printerr(0, "WARNING: handle_gssd_upcall: "
>> "failed to find uid "
>> - "in upcall string '%s'\n", lbuf);
>> - return;
>> + "in upcall string '%s'\n", info->lbuf);
>> + goto out;
>> }
>>
>> if (enctypes && parse_enctypes(enctypes) != 0) {
>> printerr(0, "WARNING: handle_gssd_upcall: "
>> "parsing encryption types failed: errno %d\n", errno);
>> - return;
>> + goto out;
>> }
>>
>> if (target && strlen(target) < 1) {
>> printerr(0, "WARNING: handle_gssd_upcall: "
>> "failed to parse target name "
>> - "in upcall string '%s'\n", lbuf);
>> - return;
>> + "in upcall string '%s'\n", info->lbuf);
>> + goto out;
>> }
>>
>> /*
>> @@ -823,8 +789,8 @@ handle_gssd_upcall(struct clnt_info *clp)
>> if (service && strlen(service) < 1) {
>> printerr(0, "WARNING: handle_gssd_upcall: "
>> "failed to parse service type "
>> - "in upcall string '%s'\n", lbuf);
>> - return;
>> + "in upcall string '%s'\n", info->lbuf);
>> + goto out;
>> }
>>
>> if (strcmp(mech, "krb5") == 0 && clp->servername)
>> @@ -835,5 +801,8 @@ handle_gssd_upcall(struct clnt_info *clp)
>> "received unknown gss mech '%s'\n", mech);
>> do_error_downcall(clp->gssd_fd, uid, -EACCES);
>> }
>> +out:
>> + free(info);
>> + return;
>> }
>>
>>
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