Tidy up the end-of-data handling in backup
* Increase transfer buffer size to 32K
* Add logging about error conditions and fd teardown
* Pass the fd number as a command line option to the 'bu' subprocess
* Properly harvest the 'bu' subprocess after it's done
Change-Id: Id44dde25778ecf43c5604fd9d01d726ba58861e5
diff --git a/adb/backup_service.c b/adb/backup_service.c
index 2e6e754..4f0c8ac 100644
--- a/adb/backup_service.c
+++ b/adb/backup_service.c
@@ -22,6 +22,23 @@
#define TRACE_TAG TRACE_ADB
#include "adb.h"
+// socketpair but do *not* mark as close_on_exec
+static int backup_socketpair(int sv[2]) {
+ int rc = unix_socketpair( AF_UNIX, SOCK_STREAM, 0, sv );
+ if (rc < 0)
+ return -1;
+
+ return 0;
+}
+
+static void* backup_child_waiter(void* pid_cookie) {
+ int status;
+
+ waitpid((pid_t) pid_cookie, &status, 0);
+ D("harvested backup/restore child, status=%d\n", status);
+ return NULL;
+}
+
/* returns the data socket passing the backup data here for forwarding */
int backup_service(BackupOperation op, char* args) {
pid_t pid;
@@ -42,12 +59,15 @@
// set up the pipe from the subprocess to here
// parent will read s[0]; child will write s[1]
- if (adb_socketpair(s)) {
+ if (backup_socketpair(s)) {
D("can't create backup/restore socketpair\n");
fprintf(stderr, "unable to create backup/restore socketpair\n");
return -1;
}
+ D("Backup/restore socket pair: (send=%d, receive=%d)\n", s[1], s[0]);
+ close_on_exec(s[0]); // only the side we hold on to
+
// spin off the child process to run the backup command
pid = fork();
if (pid < 0) {
@@ -61,12 +81,14 @@
// Great, we're off and running.
if (pid == 0) {
+ // child -- actually run the backup here
char* p;
int argc;
+ char portnum[16];
char** bu_args;
- // child -- actually run the backup here
- argc = 2; // room for the basic 'bu' argv[0] and '[operation]' argv[1]
+ // fixed args: [0] is 'bu', [1] is the port number, [2] is the 'operation' string
+ argc = 3;
for (p = (char*)args; p && *p; ) {
argc++;
while (*p && *p != ':') p++;
@@ -74,9 +96,13 @@
}
bu_args = (char**) alloca(argc*sizeof(char*) + 1);
- bu_args[0] = "bu";
- bu_args[1] = operation;
- argc = 2; // run through again to build the argv array
+
+ // run through again to build the argv array
+ argc = 0;
+ bu_args[argc++] = "bu";
+ snprintf(portnum, sizeof(portnum), "%d", s[1]);
+ bu_args[argc++] = portnum;
+ bu_args[argc++] = operation;
for (p = (char*)args; p && *p; ) {
bu_args[argc++] = p;
while (*p && *p != ':') p++;
@@ -90,7 +116,6 @@
// Close the half of the socket that we don't care about, route 'bu's console
// to the output socket, and off we go
adb_close(s[0]);
- dup2(s[1], socketnum);
// off we go
execvp("/system/bin/bu", (char * const *)bu_args);
@@ -98,8 +123,18 @@
fprintf(stderr, "Unable to exec 'bu', bailing\n");
exit(-1);
} else {
+ adb_thread_t t;
+
// parent, i.e. adbd -- close the sending half of the socket
+ D("fork() returned pid %d\n", pid);
adb_close(s[1]);
+
+ // spin a thread to harvest the child process
+ if (adb_thread_create(&t, backup_child_waiter, (void*)pid)) {
+ adb_close(s[0]);
+ D("Unable to create child harvester\n");
+ return -1;
+ }
}
// we'll be reading from s[0] as the data is sent by the child process
diff --git a/adb/commandline.c b/adb/commandline.c
index 2dc86f2..28bae98 100644
--- a/adb/commandline.c
+++ b/adb/commandline.c
@@ -239,18 +239,23 @@
}
static void copy_to_file(int inFd, int outFd) {
- char buf[4096];
+ const size_t BUFSIZE = 32 * 1024;
+ char* buf = (char*) malloc(BUFSIZE);
int len;
long total = 0;
D("copy_to_file(%d -> %d)\n", inFd, outFd);
for (;;) {
- len = adb_read(inFd, buf, sizeof(buf));
+ len = adb_read(inFd, buf, BUFSIZE);
if (len == 0) {
+ D("copy_to_file() : read 0 bytes; exiting\n");
break;
}
if (len < 0) {
- if (errno == EINTR) continue;
+ if (errno == EINTR) {
+ D("copy_to_file() : EINTR, retrying\n");
+ continue;
+ }
D("copy_to_file() : error %d\n", errno);
break;
}
@@ -258,6 +263,7 @@
total += len;
}
D("copy_to_file() finished after %lu bytes\n", total);
+ free(buf);
}
static void *stdin_read_thread(void *x)
diff --git a/adb/sockets.c b/adb/sockets.c
index 7219293..80152f2 100644
--- a/adb/sockets.c
+++ b/adb/sockets.c
@@ -288,6 +288,7 @@
if(errno == EAGAIN) return;
if(errno == EINTR) continue;
}
+ D(" closing after write because r=%d and errno is %d\n", r, errno);
s->close(s);
return;
}
@@ -303,6 +304,7 @@
** we can now destroy it.
*/
if (s->closing) {
+ D(" closing because 'closing' is set after write\n");
s->close(s);
return;
}
@@ -372,6 +374,7 @@
}
/* Don't allow a forced eof if data is still there */
if((s->fde.force_eof && !r) || is_eof) {
+ D(" closing because is_eof=%d r=%d s->fde.force_eof=%d\n", is_eof, r, s->fde.force_eof);
s->close(s);
}
}