+static const struct inode_operations yaffs_dir_inode_operations = {
+ .create = yaffs_create,
+ .lookup = yaffs_lookup,
+ .link = yaffs_link,
+ .unlink = yaffs_unlink,
+ .symlink = yaffs_symlink,
+ .mkdir = yaffs_mkdir,
+ .rmdir = yaffs_unlink,
+ .mknod = yaffs_mknod,
+ .rename = yaffs_rename,
+ .setattr = yaffs_setattr,
+ .listxattr = yaffs_listxattr,
+#ifdef YAFFS_USE_XATTR
+ .setxattr = yaffs_setxattr,
+ .getxattr = yaffs_getxattr,
+ .removexattr = yaffs_removexattr,
+#endif
+};
+
+/*-----------------------------------------------------------------*/
+/* Directory search context allows us to unlock access to yaffs during
+ * filldir without causing problems with the directory being modified.
+ * This is similar to the tried and tested mechanism used in yaffs direct.
+ *
+ * A search context iterates along a doubly linked list of siblings in the
+ * directory. If the iterating object is deleted then this would corrupt
+ * the list iteration, likely causing a crash. The search context avoids
+ * this by using the remove_obj_fn to move the search context to the
+ * next object before the object is deleted.
+ *
+ * Many readdirs (and thus seach conexts) may be alive simulateously so
+ * each struct yaffs_dev has a list of these.
+ *
+ * A seach context lives for the duration of a readdir.
+ *
+ * All these functions must be called while yaffs is locked.
+ */
+
+struct yaffs_search_context {
+ struct yaffs_dev *dev;
+ struct yaffs_obj *dir_obj;
+ struct yaffs_obj *next_return;
+ struct list_head others;
+};
+
+/*
+ * yaffs_new_search() creates a new search context, initialises it and
+ * adds it to the device's search context list.
+ *
+ * Called at start of readdir.
+ */
+static struct yaffs_search_context *yaffs_new_search(struct yaffs_obj *dir)
+{
+ struct yaffs_dev *dev = dir->my_dev;
+ struct yaffs_search_context *sc =
+ kmalloc(sizeof(struct yaffs_search_context), GFP_NOFS);
+ if (sc) {
+ sc->dir_obj = dir;
+ sc->dev = dev;
+ if (list_empty(&sc->dir_obj->variant.dir_variant.children))
+ sc->next_return = NULL;
+ else
+ sc->next_return =
+ list_entry(dir->variant.dir_variant.children.next,
+ struct yaffs_obj, siblings);
+ INIT_LIST_HEAD(&sc->others);
+ list_add(&sc->others, &(yaffs_dev_to_lc(dev)->search_contexts));
+ }
+ return sc;
+}
+
+/*
+ * yaffs_search_end() disposes of a search context and cleans up.
+ */
+static void yaffs_search_end(struct yaffs_search_context *sc)
+{
+ if (sc) {
+ list_del(&sc->others);
+ kfree(sc);
+ }
+}
+
+/*
+ * yaffs_search_advance() moves a search context to the next object.
+ * Called when the search iterates or when an object removal causes
+ * the search context to be moved to the next object.
+ */
+static void yaffs_search_advance(struct yaffs_search_context *sc)
+{
+ if (!sc)
+ return;
+
+ if (sc->next_return == NULL ||
+ list_empty(&sc->dir_obj->variant.dir_variant.children))
+ sc->next_return = NULL;
+ else {
+ struct list_head *next = sc->next_return->siblings.next;
+
+ if (next == &sc->dir_obj->variant.dir_variant.children)
+ sc->next_return = NULL; /* end of list */
+ else
+ sc->next_return =
+ list_entry(next, struct yaffs_obj, siblings);
+ }
+}
+
+/*
+ * yaffs_remove_obj_callback() is called when an object is unlinked.
+ * We check open search contexts and advance any which are currently
+ * on the object being iterated.
+ */
+static void yaffs_remove_obj_callback(struct yaffs_obj *obj)
+{
+
+ struct list_head *i;
+ struct yaffs_search_context *sc;
+ struct list_head *search_contexts =
+ &(yaffs_dev_to_lc(obj->my_dev)->search_contexts);
+
+ /* Iterate through the directory search contexts.
+ * If any are currently on the object being removed, then advance
+ * the search context to the next object to prevent a hanging pointer.
+ */
+ list_for_each(i, search_contexts) {
+ sc = list_entry(i, struct yaffs_search_context, others);
+ if (sc->next_return == obj)
+ yaffs_search_advance(sc);
+ }
+
+}
+
+
+/*-----------------------------------------------------------------*/
+
+#ifdef YAFFS_USE_DIR_ITERATE
+static int yaffs_iterate(struct file *f, struct dir_context *dc)
+{
+ struct yaffs_obj *obj;
+ struct yaffs_dev *dev;
+ struct yaffs_search_context *sc;
+ unsigned long curoffs;
+ struct yaffs_obj *l;
+ int ret_val = 0;
+
+ char name[YAFFS_MAX_NAME_LENGTH + 1];
+
+ obj = yaffs_dentry_to_obj(Y_GET_DENTRY(f));
+ dev = obj->my_dev;
+
+ yaffs_gross_lock(dev);
+
+ yaffs_dev_to_lc(dev)->readdir_process = current;
+
+ sc = yaffs_new_search(obj);
+ if (!sc) {
+ ret_val = -ENOMEM;
+ goto out;
+ }
+
+ if (!dir_emit_dots(f, dc))
+ goto out;
+
+ curoffs = 1;
+
+ while (sc->next_return) {
+ curoffs++;
+ l = sc->next_return;
+ if (curoffs >= dc->pos) {
+ int this_inode = yaffs_get_obj_inode(l);
+ int this_type = yaffs_get_obj_type(l);
+
+ yaffs_get_obj_name(l, name, YAFFS_MAX_NAME_LENGTH + 1);
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_readdir: %s inode %d",
+ name, yaffs_get_obj_inode(l));
+
+ yaffs_gross_unlock(dev);
+
+ if (!dir_emit(dc,
+ name,
+ strlen(name),
+ this_inode,
+ this_type)) {
+ yaffs_gross_lock(dev);
+ goto out;
+ }
+
+ yaffs_gross_lock(dev);
+
+ dc->pos++;
+ f->f_pos++;
+ }
+ yaffs_search_advance(sc);
+ }
+
+out:
+ yaffs_search_end(sc);
+ yaffs_dev_to_lc(dev)->readdir_process = NULL;
+ yaffs_gross_unlock(dev);
+
+ return ret_val;
+}
+
+#else
+
+static int yaffs_readdir(struct file *f, void *dirent, filldir_t filldir)
+{
+ struct yaffs_obj *obj;
+ struct yaffs_dev *dev;
+ struct yaffs_search_context *sc;
+ struct inode *inode = Y_GET_DENTRY(f)->d_inode;
+ unsigned long offset, curoffs;
+ struct yaffs_obj *l;
+ int ret_val = 0;
+
+ char name[YAFFS_MAX_NAME_LENGTH + 1];
+
+ obj = yaffs_dentry_to_obj(Y_GET_DENTRY(f));
+ dev = obj->my_dev;
+
+ yaffs_gross_lock(dev);
+
+ yaffs_dev_to_lc(dev)->readdir_process = current;
+
+ offset = f->f_pos;
+
+ sc = yaffs_new_search(obj);
+ if (!sc) {
+ ret_val = -ENOMEM;
+ goto out;
+ }
+
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_readdir: starting at %d", (int)offset);
+
+ if (offset == 0) {
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_readdir: entry . ino %d",
+ (int)inode->i_ino);
+ yaffs_gross_unlock(dev);
+ if (filldir(dirent, ".", 1, offset, inode->i_ino, DT_DIR) < 0) {
+ yaffs_gross_lock(dev);
+ goto out;
+ }
+ yaffs_gross_lock(dev);
+ offset++;
+ f->f_pos++;
+ }
+ if (offset == 1) {
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_readdir: entry .. ino %d",
+ (int)f->f_dentry->d_parent->d_inode->i_ino);
+ yaffs_gross_unlock(dev);
+ if (filldir(dirent, "..", 2, offset,
+ f->f_dentry->d_parent->d_inode->i_ino,
+ DT_DIR) < 0) {
+ yaffs_gross_lock(dev);
+ goto out;
+ }
+ yaffs_gross_lock(dev);
+ offset++;
+ f->f_pos++;
+ }
+
+ curoffs = 1;
+
+ /* If the directory has changed since the open or last call to
+ readdir, rewind to after the 2 canned entries. */
+ if (f->f_version != inode->i_version) {
+ offset = 2;
+ f->f_pos = offset;
+ f->f_version = inode->i_version;
+ }
+
+ while (sc->next_return) {
+ curoffs++;
+ l = sc->next_return;
+ if (curoffs >= offset) {
+ int this_inode = yaffs_get_obj_inode(l);
+ int this_type = yaffs_get_obj_type(l);
+
+ yaffs_get_obj_name(l, name, YAFFS_MAX_NAME_LENGTH + 1);
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_readdir: %s inode %d",
+ name, yaffs_get_obj_inode(l));
+
+ yaffs_gross_unlock(dev);
+
+ if (filldir(dirent,
+ name,
+ strlen(name),
+ offset, this_inode, this_type) < 0) {
+ yaffs_gross_lock(dev);
+ goto out;
+ }
+
+ yaffs_gross_lock(dev);
+
+ offset++;
+ f->f_pos++;
+ }
+ yaffs_search_advance(sc);
+ }
+
+out:
+ yaffs_search_end(sc);
+ yaffs_dev_to_lc(dev)->readdir_process = NULL;
+ yaffs_gross_unlock(dev);
+
+ return ret_val;
+}
+
+#endif
+
+static const struct file_operations yaffs_dir_operations = {
+ .read = generic_read_dir,
+#ifdef YAFFS_USE_DIR_ITERATE
+ .iterate = yaffs_iterate,
+#else
+ .readdir = yaffs_readdir,
+#endif
+ .fsync = yaffs_sync_object,
+ .llseek = generic_file_llseek,
+};
+
+static void yaffs_fill_inode_from_obj(struct inode *inode,
+ struct yaffs_obj *obj)
+{
+ if (inode && obj) {
+
+ /* Check mode against the variant type and attempt to repair if broken. */
+ u32 mode = obj->yst_mode;
+ switch (obj->variant_type) {
+ case YAFFS_OBJECT_TYPE_FILE:
+ if (!S_ISREG(mode)) {
+ obj->yst_mode &= ~S_IFMT;
+ obj->yst_mode |= S_IFREG;
+ }
+
+ break;
+ case YAFFS_OBJECT_TYPE_SYMLINK:
+ if (!S_ISLNK(mode)) {
+ obj->yst_mode &= ~S_IFMT;
+ obj->yst_mode |= S_IFLNK;
+ }
+
+ break;
+ case YAFFS_OBJECT_TYPE_DIRECTORY:
+ if (!S_ISDIR(mode)) {
+ obj->yst_mode &= ~S_IFMT;
+ obj->yst_mode |= S_IFDIR;
+ }
+
+ break;
+ case YAFFS_OBJECT_TYPE_UNKNOWN:
+ case YAFFS_OBJECT_TYPE_HARDLINK:
+ case YAFFS_OBJECT_TYPE_SPECIAL:
+ default:
+ /* TODO? */
+ break;
+ }
+
+ inode->i_flags |= S_NOATIME;
+
+ inode->i_ino = obj->obj_id;
+ inode->i_mode = obj->yst_mode;
+ inode->i_uid = MAKE_uid(obj->yst_uid);
+ inode->i_gid = MAKE_gid(obj->yst_gid);
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 19))
+ inode->i_blksize = inode->i_sb->s_blocksize;
+#endif
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+
+ inode->i_rdev = old_decode_dev(obj->yst_rdev);
+ inode->i_atime.tv_sec = (YTIME_T) (obj->yst_atime);
+ inode->i_atime.tv_nsec = 0;
+ inode->i_mtime.tv_sec = (YTIME_T) obj->yst_mtime;
+ inode->i_mtime.tv_nsec = 0;
+ inode->i_ctime.tv_sec = (YTIME_T) obj->yst_ctime;
+ inode->i_ctime.tv_nsec = 0;
+#else
+ inode->i_rdev = obj->yst_rdev;
+ inode->i_atime = obj->yst_atime;
+ inode->i_mtime = obj->yst_mtime;
+ inode->i_ctime = obj->yst_ctime;
+#endif
+ inode->i_size = yaffs_get_obj_length(obj);
+ inode->i_blocks = (inode->i_size + 511) >> 9;
+
+ set_nlink(inode, yaffs_get_obj_link_count(obj));
+
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_fill_inode mode %x uid %d gid %d size %lld count %d",
+ inode->i_mode, obj->yst_uid, obj->yst_gid,
+ inode->i_size, atomic_read(&inode->i_count));
+
+ switch (obj->yst_mode & S_IFMT) {
+ default: /* fifo, device or socket */
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+ init_special_inode(inode, obj->yst_mode,
+ old_decode_dev(obj->yst_rdev));
+#else
+ init_special_inode(inode, obj->yst_mode,
+ (dev_t) (obj->yst_rdev));
+#endif
+ break;
+ case S_IFREG: /* file */
+ inode->i_op = &yaffs_file_inode_operations;
+ inode->i_fop = &yaffs_file_operations;
+ inode->i_mapping->a_ops =
+ &yaffs_file_address_operations;
+ break;
+ case S_IFDIR: /* directory */
+ inode->i_op = &yaffs_dir_inode_operations;
+ inode->i_fop = &yaffs_dir_operations;
+ break;
+ case S_IFLNK: /* symlink */
+ inode->i_op = &yaffs_symlink_inode_operations;
+ break;
+ }
+
+ yaffs_inode_to_obj_lv(inode) = obj;
+
+ obj->my_inode = inode;
+
+ } else {
+ yaffs_trace(YAFFS_TRACE_OS,
+ "yaffs_fill_inode invalid parameters");
+ }
+
+}
+
+
+
+/*
+ * yaffs background thread functions .
+ * yaffs_bg_thread_fn() the thread function
+ * yaffs_bg_start() launches the background thread.
+ * yaffs_bg_stop() cleans up the background thread.
+ *
+ * NB:
+ * The thread should only run after the yaffs is initialised
+ * The thread should be stopped before yaffs is unmounted.
+ * The thread should not do any writing while the fs is in read only.
+ */
+
+static unsigned yaffs_bg_gc_urgency(struct yaffs_dev *dev)
+{
+ unsigned erased_chunks =
+ dev->n_erased_blocks * dev->param.chunks_per_block;
+ struct yaffs_linux_context *context = yaffs_dev_to_lc(dev);
+ unsigned scattered = 0; /* Free chunks not in an erased block */
+
+ if (erased_chunks < dev->n_free_chunks)
+ scattered = (dev->n_free_chunks - erased_chunks);
+
+ if (!context->bg_running)
+ return 0;
+ else if (scattered < (dev->param.chunks_per_block * 2))
+ return 0;
+ else if (erased_chunks > dev->n_free_chunks / 2)
+ return 0;
+ else if (erased_chunks > dev->n_free_chunks / 4)
+ return 1;
+ else
+ return 2;
+}
+
+#ifdef YAFFS_COMPILE_BACKGROUND
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0))
+struct timer_struct {
+ struct task_struct *task;
+ struct timer_list timer;
+};
+#endif
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0))
+static void yaffs_background_waker(struct timer_list *t)
+{
+ struct timer_struct *ts = from_timer(ts, t, timer);
+
+ wake_up_process(ts->task);
+}
+#else
+void yaffs_background_waker(unsigned long data)
+{
+ wake_up_process((struct task_struct *)data);
+}
+#endif
+
+static int yaffs_bg_thread_fn(void *data)
+{
+ struct yaffs_dev *dev = (struct yaffs_dev *)data;
+ struct yaffs_linux_context *context = yaffs_dev_to_lc(dev);
+ unsigned long now = jiffies;
+ unsigned long next_dir_update = now;
+ unsigned long next_gc = now;
+ unsigned long expires;
+ unsigned int urgency;
+
+ int gc_result;
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0))
+ struct timer_struct timer;
+#else
+ struct timer_list timer;
+#endif
+
+ yaffs_trace(YAFFS_TRACE_BACKGROUND,
+ "yaffs_background starting for dev %p", (void *)dev);
+
+#ifdef YAFFS_COMPILE_FREEZER
+ set_freezable();
+#endif
+ while (context->bg_running) {
+ yaffs_trace(YAFFS_TRACE_BACKGROUND, "yaffs_background");
+
+ if (kthread_should_stop())
+ break;
+
+#ifdef YAFFS_COMPILE_FREEZER
+ if (try_to_freeze())
+ continue;
+#endif
+ yaffs_gross_lock(dev);
+
+ now = jiffies;
+
+ if (time_after(now, next_dir_update) && yaffs_bg_enable) {
+ yaffs_update_dirty_dirs(dev);
+ next_dir_update = now + HZ;
+ }
+
+ if (time_after(now, next_gc) && yaffs_bg_enable) {
+ if (!dev->is_checkpointed) {
+ urgency = yaffs_bg_gc_urgency(dev);
+ gc_result = yaffs_bg_gc(dev, urgency);
+ if (urgency > 1)
+ next_gc = now + HZ / 20 + 1;
+ else if (urgency > 0)
+ next_gc = now + HZ / 10 + 1;
+ else
+ next_gc = now + HZ * 2;
+ } else {
+ /*
+ * gc not running so set to next_dir_update
+ * to cut down on wake ups
+ */
+ next_gc = next_dir_update;
+ }
+ }
+ yaffs_gross_unlock(dev);
+ expires = next_dir_update;
+ if (time_before(next_gc, expires))
+ expires = next_gc;
+ if (time_before(expires, now))
+ expires = now + HZ;
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0))
+ Y_INIT_TIMER(&timer.timer, yaffs_background_waker);
+ timer.timer.expires = expires + 1;
+ timer.task = current;
+#else
+ Y_INIT_TIMER(&timer);
+ timer.expires = expires + 1;
+ timer.data = (unsigned long)current;
+ timer.function = yaffs_background_waker;
+#endif
+
+ set_current_state(TASK_INTERRUPTIBLE);
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0))
+ add_timer(&timer.timer);
+ schedule();
+ del_timer_sync(&timer.timer);
+#else
+ add_timer(&timer);
+ schedule();
+ del_timer_sync(&timer);
+#endif
+ }
+
+ return 0;
+}
+
+static int yaffs_bg_start(struct yaffs_dev *dev)
+{
+ int retval = 0;
+ struct yaffs_linux_context *context = yaffs_dev_to_lc(dev);
+
+ if (dev->read_only)
+ return -1;
+
+ context->bg_running = 1;
+
+ context->bg_thread = kthread_run(yaffs_bg_thread_fn,
+ (void *)dev, "yaffs-bg-%d",
+ context->mount_id);
+
+ if (IS_ERR(context->bg_thread)) {
+ retval = PTR_ERR(context->bg_thread);
+ context->bg_thread = NULL;
+ context->bg_running = 0;
+ }
+ return retval;
+}
+
+static void yaffs_bg_stop(struct yaffs_dev *dev)
+{
+ struct yaffs_linux_context *ctxt = yaffs_dev_to_lc(dev);
+
+ ctxt->bg_running = 0;
+
+ if (ctxt->bg_thread) {
+ kthread_stop(ctxt->bg_thread);
+ ctxt->bg_thread = NULL;
+ }
+}
+#else
+static int yaffs_bg_thread_fn(void *data)
+{
+ return 0;
+}
+
+static int yaffs_bg_start(struct yaffs_dev *dev)
+{
+ return 0;
+}
+
+static void yaffs_bg_stop(struct yaffs_dev *dev)
+{
+}
+#endif