commit d6b0d375490f9c31da0131582b7d77d1fdd79706
author Christopher Ferris <cferris@google.com> Thu Oct 06 12:51:20 2016 -0700
committer Christopher Ferris <cferris@google.com> Fri Oct 07 12:16:00 2016 -0700
tree ccf2cca54b571c40b673ace3142c5b0a75ea7c01
parent 0d762648d0b9cb29f13f3f8cb7815236078fafbd

Small clean up of fuse code.

- Add TEMP_FAILURE_RETRY around all relevant system calls.
- Cleanup some of the read calls.
- Add error log messages when read/write calls do not actually read/write the
  expected number of bytes.
- Add error messages for write failures in fuse_status/fuse_replay.

Test: Attached to the sdcard process and stepped through most of the modified
Test: code. Also, create/read/write/delete files in /storage/emulated/0
Test: directory.

Change-Id: I73e4c0db861960f4c0af1bf96b06cd61fa74be69

sdcard/sdcard.cpp

diff --git a/sdcard/sdcard.cpp b/sdcard/sdcard.cpp
index 70bbf26..bc502a0 100644
--- a/sdcard/sdcard.cpp
+++ b/sdcard/sdcard.cpp
@@ -111,7 +111,7 @@
     char event_buf[512];
 
     int nfd = inotify_init();
-    if (nfd < 0) {
+    if (nfd == -1) {
         PLOG(ERROR) << "inotify_init failed";
         return;
     }
@@ -142,17 +142,19 @@
         }
 
         int event_pos = 0;
-        int res = read(nfd, event_buf, sizeof(event_buf));
-        if (res < (int) sizeof(*event)) {
-            if (errno == EINTR)
-                continue;
+        ssize_t res = TEMP_FAILURE_RETRY(read(nfd, event_buf, sizeof(event_buf)));
+        if (res == -1) {
             PLOG(ERROR) << "failed to read inotify event";
             return;
+        } else if (static_cast<size_t>(res) < sizeof(*event)) {
+            LOG(ERROR) << "failed to read inotify event: read " << res << " expected "
+                       << sizeof(event_buf);
+            return;
         }
 
-        while (res >= (int) sizeof(*event)) {
+        while (res >= static_cast<ssize_t>(sizeof(*event))) {
             int event_size;
-            event = (struct inotify_event *) (event_buf + event_pos);
+            event = reinterpret_cast<struct inotify_event*>(event_buf + event_pos);
 
             DLOG(INFO) << "inotify event: " << std::hex << event->mask << std::dec;
             if ((event->mask & IN_IGNORED) == IN_IGNORED) {
@@ -171,7 +173,7 @@
 static int fuse_setup(struct fuse* fuse, gid_t gid, mode_t mask) {
     char opts[256];
 
-    fuse->fd = open("/dev/fuse", O_RDWR);
+    fuse->fd = TEMP_FAILURE_RETRY(open("/dev/fuse", O_RDWR | O_CLOEXEC));
     if (fuse->fd == -1) {
         PLOG(ERROR) << "failed to open fuse device";
         return -1;
@@ -182,8 +184,8 @@
     snprintf(opts, sizeof(opts),
             "fd=%i,rootmode=40000,default_permissions,allow_other,user_id=%d,group_id=%d",
             fuse->fd, fuse->global->uid, fuse->global->gid);
-    if (mount("/dev/fuse", fuse->dest_path, "fuse", MS_NOSUID | MS_NODEV | MS_NOEXEC |
-            MS_NOATIME, opts) != 0) {
+    if (mount("/dev/fuse", fuse->dest_path, "fuse", MS_NOSUID | MS_NODEV | MS_NOEXEC | MS_NOATIME,
+              opts) == -1) {
         PLOG(ERROR) << "failed to mount fuse filesystem";
         return -1;
     }
@@ -321,7 +323,7 @@
             fsuid, fsgid, multi_user?"multiuser,":"", mask, userid, gid);
 
     if (mount(source_path.c_str(), dest_path.c_str(), "sdcardfs",
-                        MS_NOSUID | MS_NODEV | MS_NOEXEC | MS_NOATIME, opts.c_str()) != 0) {
+              MS_NOSUID | MS_NODEV | MS_NOEXEC | MS_NOATIME, opts.c_str()) == -1) {
         PLOG(ERROR) << "failed to mount sdcardfs filesystem";
         return false;
     }
@@ -480,7 +482,7 @@
 
     rlim.rlim_cur = 8192;
     rlim.rlim_max = 8192;
-    if (setrlimit(RLIMIT_NOFILE, &rlim)) {
+    if (setrlimit(RLIMIT_NOFILE, &rlim) == -1) {
         PLOG(ERROR) << "setting RLIMIT_NOFILE failed";
     }