diff options
| -rw-r--r-- | example/notify_store_retrieve.c | 49 |
1 files changed, 38 insertions, 11 deletions
diff --git a/example/notify_store_retrieve.c b/example/notify_store_retrieve.c index c4d0087..d7e1c4b 100644 --- a/example/notify_store_retrieve.c +++ b/example/notify_store_retrieve.c @@ -81,7 +81,9 @@ #define FILE_NAME "current_time" static char file_contents[MAX_STR_LEN]; static int lookup_cnt = 0; +static int open_cnt = 0; static size_t file_size; +static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER; /* Keep track if we ever stored data (==1), and received it back correctly (==2) */ @@ -139,7 +141,6 @@ static void tfs_lookup(fuse_req_t req, fuse_ino_t parent, goto err_out; else if (strcmp(name, FILE_NAME) == 0) { e.ino = FILE_INO; - lookup_cnt++; } else goto err_out; @@ -148,6 +149,18 @@ static void tfs_lookup(fuse_req_t req, fuse_ino_t parent, if (tfs_stat(e.ino, &e.attr) != 0) goto err_out; fuse_reply_entry(req, &e); + + /* + * must only be set when the kernel knows about the entry, + * otherwise update_fs_loop() might see a positive count, but kernel + * would not have the entry yet + */ + if (e.ino == FILE_INO) { + pthread_mutex_lock(&lock); + lookup_cnt++; + pthread_mutex_unlock(&lock); + } + return; err_out: @@ -157,9 +170,11 @@ err_out: static void tfs_forget (fuse_req_t req, fuse_ino_t ino, uint64_t nlookup) { (void) req; - if(ino == FILE_INO) + if(ino == FILE_INO) { + pthread_mutex_lock(&lock); lookup_cnt -= nlookup; - else + pthread_mutex_unlock(&lock); + } else assert(ino == FUSE_ROOT_ID); fuse_reply_none(req); } @@ -232,9 +247,12 @@ static void tfs_open(fuse_req_t req, fuse_ino_t ino, fuse_reply_err(req, EISDIR); else if ((fi->flags & O_ACCMODE) != O_RDONLY) fuse_reply_err(req, EACCES); - else if (ino == FILE_INO) + else if (ino == FILE_INO) { fuse_reply_open(req, fi); - else { + pthread_mutex_lock(&lock); + open_cnt++; + pthread_mutex_unlock(&lock); + } else { // This should not happen fprintf(stderr, "Got open for non-existing inode!\n"); fuse_reply_err(req, ENOENT); @@ -315,7 +333,8 @@ static void* update_fs_loop(void *data) { while(!is_umount) { update_fs(); - if (!options.no_notify && lookup_cnt) { + pthread_mutex_lock(&lock); + if (!options.no_notify && open_cnt && lookup_cnt) { /* Only send notification if the kernel is aware of the inode */ bufv.count = 1; @@ -325,11 +344,17 @@ static void* update_fs_loop(void *data) { bufv.buf[0].mem = file_contents; bufv.buf[0].flags = 0; - /* This shouldn't fail, but apparently it sometimes - does - see https://github.com/libfuse/libfuse/issues/105 */ + /* + * Some errors (ENOENT, EBADFD, ENODEV) have to be accepted as they + * might come up during umount, when kernel side already releases + * all inodes, but does not send FUSE_DESTROY yet. + */ + ret = fuse_lowlevel_notify_store(se, FILE_INO, 0, &bufv, 0); - if (ret != 0 && !is_umount) { - fprintf(stderr, "ERROR: fuse_lowlevel_notify_store() failed with %s (%d)\n", + if ((ret != 0 && !is_umount) && + ret != -ENOENT && ret != -EBADFD && ret != -ENODEV) { + fprintf(stderr, + "ERROR: fuse_lowlevel_notify_store() failed with %s (%d)\n", strerror(-ret), -ret); abort(); } @@ -338,10 +363,12 @@ static void* update_fs_loop(void *data) { kernel to send us back the stored data */ ret = fuse_lowlevel_notify_retrieve(se, FILE_INO, MAX_STR_LEN, 0, (void*) strdup(file_contents)); - assert(ret == 0 || is_umount); + assert((ret == 0 || is_umount) || ret == -ENOENT || ret == -EBADFD || + ret != -ENODEV); if(retrieve_status == 0) retrieve_status = 1; } + pthread_mutex_unlock(&lock); sleep(options.update_interval); } return NULL; |