stream_smb: locking to bypass libsmbclient issues

Thread-unsafe libsmbclient is likely to crash when used simultaneously
across threads. For example, by:

    mpv "smb://...mkv" --sub-file "smb://...srt"

Work around this by locking all calls to this library under a single
global mutex. This is a temporary solution. When the libsmbclient bug
[1] is fixed, switch to the code from branch [2] which uses a new api to
create per-thread smb contexts. Fixes [3].

[1] https://bugzilla.samba.org/show_bug.cgi?id=11413
[2] https://github.com/orbisvicis/mpv/tree/smbclient_threaded_api
[3] https://github.com/mpv-player/mpv/issues/5936

(cherry picked from commit 112b3fa922)
This commit is contained in:
Yclept Nemo
2018-07-29 12:59:03 +03:00
committed by Jan Ekström
parent 0d134dc010
commit 021bea1592
+21 -1
View File
@@ -21,6 +21,7 @@
#include <libsmbclient.h>
#include <unistd.h>
#include <pthread.h>
#include "common/msg.h"
#include "stream.h"
@@ -31,6 +32,8 @@
#error GPL only
#endif
static pthread_mutex_t smb_lock = PTHREAD_MUTEX_INITIALIZER;
struct priv {
int fd;
};
@@ -46,8 +49,10 @@ static int control(stream_t *s, int cmd, void *arg) {
struct priv *p = s->priv;
switch(cmd) {
case STREAM_CTRL_GET_SIZE: {
pthread_mutex_lock(&smb_lock);
off_t size = smbc_lseek(p->fd,0,SEEK_END);
smbc_lseek(p->fd,s->pos,SEEK_SET);
pthread_mutex_unlock(&smb_lock);
if(size != (off_t)-1) {
*(int64_t *)arg = size;
return 1;
@@ -60,7 +65,10 @@ static int control(stream_t *s, int cmd, void *arg) {
static int seek(stream_t *s,int64_t newpos) {
struct priv *p = s->priv;
if(smbc_lseek(p->fd,newpos,SEEK_SET)<0) {
pthread_mutex_lock(&smb_lock);
off_t size = smbc_lseek(p->fd,newpos,SEEK_SET);
pthread_mutex_unlock(&smb_lock);
if(size<0) {
return 0;
}
return 1;
@@ -68,7 +76,9 @@ static int seek(stream_t *s,int64_t newpos) {
static int fill_buffer(stream_t *s, char* buffer, int max_len){
struct priv *p = s->priv;
pthread_mutex_lock(&smb_lock);
int r = smbc_read(p->fd,buffer,max_len);
pthread_mutex_unlock(&smb_lock);
return (r <= 0) ? -1 : r;
}
@@ -77,7 +87,9 @@ static int write_buffer(stream_t *s, char* buffer, int len) {
int r;
int wr = 0;
while (wr < len) {
pthread_mutex_lock(&smb_lock);
r = smbc_write(p->fd,buffer,len);
pthread_mutex_unlock(&smb_lock);
if (r <= 0)
return -1;
wr += r;
@@ -88,7 +100,9 @@ static int write_buffer(stream_t *s, char* buffer, int len) {
static void close_f(stream_t *s){
struct priv *p = s->priv;
pthread_mutex_lock(&smb_lock);
smbc_close(p->fd);
pthread_mutex_unlock(&smb_lock);
}
static int open_f (stream_t *stream)
@@ -110,13 +124,17 @@ static int open_f (stream_t *stream)
return STREAM_ERROR;
}
pthread_mutex_lock(&smb_lock);
err = smbc_init(smb_auth_fn, 1);
pthread_mutex_unlock(&smb_lock);
if (err < 0) {
MP_ERR(stream, "Cannot init the libsmbclient library: %d\n",err);
return STREAM_ERROR;
}
pthread_mutex_lock(&smb_lock);
fd = smbc_open(filename, m,0644);
pthread_mutex_unlock(&smb_lock);
if (fd < 0) {
MP_ERR(stream, "Could not open from LAN: '%s'\n", filename);
return STREAM_ERROR;
@@ -124,8 +142,10 @@ static int open_f (stream_t *stream)
len = 0;
if(!write) {
pthread_mutex_lock(&smb_lock);
len = smbc_lseek(fd,0,SEEK_END);
smbc_lseek (fd, 0, SEEK_SET);
pthread_mutex_unlock(&smb_lock);
}
if(len > 0 || write) {
stream->seekable = true;