Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 */
 
#include <linux/kthread.h>
#include <linux/pagemap.h>
 
#include "ctree.h"
#include "disk-io.h"
#include "free-space-cache.h"
#include "inode-map.h"
#include "transaction.h"
#include "delalloc-space.h"
 
static void fail_caching_thread(struct btrfs_root *root)
{
<------>struct btrfs_fs_info *fs_info = root->fs_info;
 
<------>btrfs_warn(fs_info, "failed to start inode caching task");
<------>btrfs_clear_pending_and_info(fs_info, INODE_MAP_CACHE,
<------><------><------><------>     "disabling inode map caching");
<------>spin_lock(&root->ino_cache_lock);
<------>root->ino_cache_state = BTRFS_CACHE_ERROR;
<------>spin_unlock(&root->ino_cache_lock);
<------>wake_up(&root->ino_cache_wait);
}
 
static int caching_kthread(void *data)
{
<------>struct btrfs_root *root = data;
<------>struct btrfs_fs_info *fs_info = root->fs_info;
<------>struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
<------>struct btrfs_key key;
<------>struct btrfs_path *path;
<------>struct extent_buffer *leaf;
<------>u64 last = (u64)-1;
<------>int slot;
<------>int ret;
 
<------>if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
<------><------>return 0;
 
<------>path = btrfs_alloc_path();
<------>if (!path) {
<------><------>fail_caching_thread(root);
<------><------>return -ENOMEM;
<------>}
 
<------>/* Since the commit root is read-only, we can safely skip locking. */
<------>path->skip_locking = 1;
<------>path->search_commit_root = 1;
<------>path->reada = READA_FORWARD;
 
<------>key.objectid = BTRFS_FIRST_FREE_OBJECTID;
<------>key.offset = 0;
<------>key.type = BTRFS_INODE_ITEM_KEY;
again:
<------>/* need to make sure the commit_root doesn't disappear */
<------>down_read(&fs_info->commit_root_sem);
 
<------>ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
<------>if (ret < 0)
<------><------>goto out;
 
<------>while (1) {
<------><------>if (btrfs_fs_closing(fs_info))
<------><------><------>goto out;
 
<------><------>leaf = path->nodes[0];
<------><------>slot = path->slots[0];
<------><------>if (slot >= btrfs_header_nritems(leaf)) {
<------><------><------>ret = btrfs_next_leaf(root, path);
<------><------><------>if (ret < 0)
<------><------><------><------>goto out;
<------><------><------>else if (ret > 0)
<------><------><------><------>break;
 
<------><------><------>if (need_resched() ||
<------><------><------>    btrfs_transaction_in_commit(fs_info)) {
<------><------><------><------>leaf = path->nodes[0];
 
<------><------><------><------>if (WARN_ON(btrfs_header_nritems(leaf) == 0))
<------><------><------><------><------>break;
 
<------><------><------><------>/*
<------><------><------><------> * Save the key so we can advances forward
<------><------><------><------> * in the next search.
<------><------><------><------> */
<------><------><------><------>btrfs_item_key_to_cpu(leaf, &key, 0);
<------><------><------><------>btrfs_release_path(path);
<------><------><------><------>root->ino_cache_progress = last;
<------><------><------><------>up_read(&fs_info->commit_root_sem);
<------><------><------><------>schedule_timeout(1);
<------><------><------><------>goto again;
<------><------><------>} else
<------><------><------><------>continue;
<------><------>}
 
<------><------>btrfs_item_key_to_cpu(leaf, &key, slot);
 
<------><------>if (key.type != BTRFS_INODE_ITEM_KEY)
<------><------><------>goto next;
 
<------><------>if (key.objectid >= root->highest_objectid)
<------><------><------>break;
 
<------><------>if (last != (u64)-1 && last + 1 != key.objectid) {
<------><------><------>__btrfs_add_free_space(fs_info, ctl, last + 1,
<------><------><------><------><------>       key.objectid - last - 1, 0);
<------><------><------>wake_up(&root->ino_cache_wait);
<------><------>}
 
<------><------>last = key.objectid;
next:
<------><------>path->slots[0]++;
<------>}
 
<------>if (last < root->highest_objectid - 1) {
<------><------>__btrfs_add_free_space(fs_info, ctl, last + 1,
<------><------><------><------>       root->highest_objectid - last - 1, 0);
<------>}
 
<------>spin_lock(&root->ino_cache_lock);
<------>root->ino_cache_state = BTRFS_CACHE_FINISHED;
<------>spin_unlock(&root->ino_cache_lock);
 
<------>root->ino_cache_progress = (u64)-1;
<------>btrfs_unpin_free_ino(root);
out:
<------>wake_up(&root->ino_cache_wait);
<------>up_read(&fs_info->commit_root_sem);
 
<------>btrfs_free_path(path);
 
<------>return ret;
}
 
static void start_caching(struct btrfs_root *root)
{
<------>struct btrfs_fs_info *fs_info = root->fs_info;
<------>struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
<------>struct task_struct *tsk;
<------>int ret;
<------>u64 objectid;
 
<------>if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
<------><------>return;
 
<------>spin_lock(&root->ino_cache_lock);
<------>if (root->ino_cache_state != BTRFS_CACHE_NO) {
<------><------>spin_unlock(&root->ino_cache_lock);
<------><------>return;
<------>}
 
<------>root->ino_cache_state = BTRFS_CACHE_STARTED;
<------>spin_unlock(&root->ino_cache_lock);
 
<------>ret = load_free_ino_cache(fs_info, root);
<------>if (ret == 1) {
<------><------>spin_lock(&root->ino_cache_lock);
<------><------>root->ino_cache_state = BTRFS_CACHE_FINISHED;
<------><------>spin_unlock(&root->ino_cache_lock);
<------><------>wake_up(&root->ino_cache_wait);
<------><------>return;
<------>}
 
<------>/*
<------> * It can be quite time-consuming to fill the cache by searching
<------> * through the extent tree, and this can keep ino allocation path
<------> * waiting. Therefore at start we quickly find out the highest
<------> * inode number and we know we can use inode numbers which fall in
<------> * [highest_ino + 1, BTRFS_LAST_FREE_OBJECTID].
<------> */
<------>ret = btrfs_find_free_objectid(root, &objectid);
<------>if (!ret && objectid <= BTRFS_LAST_FREE_OBJECTID) {
<------><------>__btrfs_add_free_space(fs_info, ctl, objectid,
<------><------><------><------>       BTRFS_LAST_FREE_OBJECTID - objectid + 1,
<------><------><------><------>       0);
<------><------>wake_up(&root->ino_cache_wait);
<------>}
 
<------>tsk = kthread_run(caching_kthread, root, "btrfs-ino-cache-%llu",
<------><------><------>  root->root_key.objectid);
<------>if (IS_ERR(tsk))
<------><------>fail_caching_thread(root);
}
 
int btrfs_find_free_ino(struct btrfs_root *root, u64 *objectid)
{
<------>if (!btrfs_test_opt(root->fs_info, INODE_MAP_CACHE))
<------><------>return btrfs_find_free_objectid(root, objectid);
 
again:
<------>*objectid = btrfs_find_ino_for_alloc(root);
 
<------>if (*objectid != 0)
<------><------>return 0;
 
<------>start_caching(root);
 
<------>wait_event(root->ino_cache_wait,
<------><------>   root->ino_cache_state == BTRFS_CACHE_FINISHED ||
<------><------>   root->ino_cache_state == BTRFS_CACHE_ERROR ||
<------><------>   root->free_ino_ctl->free_space > 0);
 
<------>if (root->ino_cache_state == BTRFS_CACHE_FINISHED &&
<------>    root->free_ino_ctl->free_space == 0)
<------><------>return -ENOSPC;
<------>else if (root->ino_cache_state == BTRFS_CACHE_ERROR)
<------><------>return btrfs_find_free_objectid(root, objectid);
<------>else
<------><------>goto again;
}
 
void btrfs_return_ino(struct btrfs_root *root, u64 objectid)
{
<------>struct btrfs_fs_info *fs_info = root->fs_info;
<------>struct btrfs_free_space_ctl *pinned = root->free_ino_pinned;
 
<------>if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
<------><------>return;
again:
<------>if (root->ino_cache_state == BTRFS_CACHE_FINISHED) {
<------><------>__btrfs_add_free_space(fs_info, pinned, objectid, 1, 0);
<------>} else {
<------><------>down_write(&fs_info->commit_root_sem);
<------><------>spin_lock(&root->ino_cache_lock);
<------><------>if (root->ino_cache_state == BTRFS_CACHE_FINISHED) {
<------><------><------>spin_unlock(&root->ino_cache_lock);
<------><------><------>up_write(&fs_info->commit_root_sem);
<------><------><------>goto again;
<------><------>}
<------><------>spin_unlock(&root->ino_cache_lock);
 
<------><------>start_caching(root);
 
<------><------>__btrfs_add_free_space(fs_info, pinned, objectid, 1, 0);
 
<------><------>up_write(&fs_info->commit_root_sem);
<------>}
}
 
/*
 * When a transaction is committed, we'll move those inode numbers which are
 * smaller than root->ino_cache_progress from pinned tree to free_ino tree, and
 * others will just be dropped, because the commit root we were searching has
 * changed.
 *
 * Must be called with root->fs_info->commit_root_sem held
 */
void btrfs_unpin_free_ino(struct btrfs_root *root)
{
<------>struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
<------>struct rb_root *rbroot = &root->free_ino_pinned->free_space_offset;
<------>spinlock_t *rbroot_lock = &root->free_ino_pinned->tree_lock;
<------>struct btrfs_free_space *info;
<------>struct rb_node *n;
<------>u64 count;
 
<------>if (!btrfs_test_opt(root->fs_info, INODE_MAP_CACHE))
<------><------>return;
 
<------>while (1) {
<------><------>spin_lock(rbroot_lock);
<------><------>n = rb_first(rbroot);
<------><------>if (!n) {
<------><------><------>spin_unlock(rbroot_lock);
<------><------><------>break;
<------><------>}
 
<------><------>info = rb_entry(n, struct btrfs_free_space, offset_index);
<------><------>BUG_ON(info->bitmap); /* Logic error */
 
<------><------>if (info->offset > root->ino_cache_progress)
<------><------><------>count = 0;
<------><------>else
<------><------><------>count = min(root->ino_cache_progress - info->offset + 1,
<------><------><------><------>    info->bytes);
 
<------><------>rb_erase(&info->offset_index, rbroot);
<------><------>spin_unlock(rbroot_lock);
<------><------>if (count)
<------><------><------>__btrfs_add_free_space(root->fs_info, ctl,
<------><------><------><------><------>       info->offset, count, 0);
<------><------>kmem_cache_free(btrfs_free_space_cachep, info);
<------>}
}
 
#define INIT_THRESHOLD	((SZ_32K / 2) / sizeof(struct btrfs_free_space))
#define INODES_PER_BITMAP (PAGE_SIZE * 8)
 
/*
 * The goal is to keep the memory used by the free_ino tree won't
 * exceed the memory if we use bitmaps only.
 */
static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
{
<------>struct btrfs_free_space *info;
<------>struct rb_node *n;
<------>int max_ino;
<------>int max_bitmaps;
 
<------>n = rb_last(&ctl->free_space_offset);
<------>if (!n) {
<------><------>ctl->extents_thresh = INIT_THRESHOLD;
<------><------>return;
<------>}
<------>info = rb_entry(n, struct btrfs_free_space, offset_index);
 
<------>/*
<------> * Find the maximum inode number in the filesystem. Note we
<------> * ignore the fact that this can be a bitmap, because we are
<------> * not doing precise calculation.
<------> */
<------>max_ino = info->bytes - 1;
 
<------>max_bitmaps = ALIGN(max_ino, INODES_PER_BITMAP) / INODES_PER_BITMAP;
<------>if (max_bitmaps <= ctl->total_bitmaps) {
<------><------>ctl->extents_thresh = 0;
<------><------>return;
<------>}
 
<------>ctl->extents_thresh = (max_bitmaps - ctl->total_bitmaps) *
<------><------><------><------>PAGE_SIZE / sizeof(*info);
}
 
/*
 * We don't fall back to bitmap, if we are below the extents threshold
 * or this chunk of inode numbers is a big one.
 */
static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
<------><------>       struct btrfs_free_space *info)
{
<------>if (ctl->free_extents < ctl->extents_thresh ||
<------>    info->bytes > INODES_PER_BITMAP / 10)
<------><------>return false;
 
<------>return true;
}
 
static const struct btrfs_free_space_op free_ino_op = {
<------>.recalc_thresholds	= recalculate_thresholds,
<------>.use_bitmap		= use_bitmap,
};
 
static void pinned_recalc_thresholds(struct btrfs_free_space_ctl *ctl)
{
}
 
static bool pinned_use_bitmap(struct btrfs_free_space_ctl *ctl,
<------><------><------>      struct btrfs_free_space *info)
{
<------>/*
<------> * We always use extents for two reasons:
<------> *
<------> * - The pinned tree is only used during the process of caching
<------> *   work.
<------> * - Make code simpler. See btrfs_unpin_free_ino().
<------> */
<------>return false;
}
 
static const struct btrfs_free_space_op pinned_free_ino_op = {
<------>.recalc_thresholds	= pinned_recalc_thresholds,
<------>.use_bitmap		= pinned_use_bitmap,
};
 
void btrfs_init_free_ino_ctl(struct btrfs_root *root)
{
<------>struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
<------>struct btrfs_free_space_ctl *pinned = root->free_ino_pinned;
 
<------>spin_lock_init(&ctl->tree_lock);
<------>ctl->unit = 1;
<------>ctl->start = 0;
<------>ctl->private = NULL;
<------>ctl->op = &free_ino_op;
<------>INIT_LIST_HEAD(&ctl->trimming_ranges);
<------>mutex_init(&ctl->cache_writeout_mutex);
 
<------>/*
<------> * Initially we allow to use 16K of ram to cache chunks of
<------> * inode numbers before we resort to bitmaps. This is somewhat
<------> * arbitrary, but it will be adjusted in runtime.
<------> */
<------>ctl->extents_thresh = INIT_THRESHOLD;
 
<------>spin_lock_init(&pinned->tree_lock);
<------>pinned->unit = 1;
<------>pinned->start = 0;
<------>pinned->private = NULL;
<------>pinned->extents_thresh = 0;
<------>pinned->op = &pinned_free_ino_op;
}
 
int btrfs_save_ino_cache(struct btrfs_root *root,
<------><------><------> struct btrfs_trans_handle *trans)
{
<------>struct btrfs_fs_info *fs_info = root->fs_info;
<------>struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
<------>struct btrfs_path *path;
<------>struct inode *inode;
<------>struct btrfs_block_rsv *rsv;
<------>struct extent_changeset *data_reserved = NULL;
<------>u64 num_bytes;
<------>u64 alloc_hint = 0;
<------>int ret;
<------>int prealloc;
<------>bool retry = false;
 
<------>/* only fs tree and subvol/snap needs ino cache */
<------>if (root->root_key.objectid != BTRFS_FS_TREE_OBJECTID &&
<------>    (root->root_key.objectid < BTRFS_FIRST_FREE_OBJECTID ||
<------>     root->root_key.objectid > BTRFS_LAST_FREE_OBJECTID))
<------><------>return 0;
 
<------>/* Don't save inode cache if we are deleting this root */
<------>if (btrfs_root_refs(&root->root_item) == 0)
<------><------>return 0;
 
<------>if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
<------><------>return 0;
 
<------>path = btrfs_alloc_path();
<------>if (!path)
<------><------>return -ENOMEM;
 
<------>rsv = trans->block_rsv;
<------>trans->block_rsv = &fs_info->trans_block_rsv;
 
<------>num_bytes = trans->bytes_reserved;
<------>/*
<------> * 1 item for inode item insertion if need
<------> * 4 items for inode item update (in the worst case)
<------> * 1 items for slack space if we need do truncation
<------> * 1 item for free space object
<------> * 3 items for pre-allocation
<------> */
<------>trans->bytes_reserved = btrfs_calc_insert_metadata_size(fs_info, 10);
<------>ret = btrfs_block_rsv_add(root, trans->block_rsv,
<------><------><------><------>  trans->bytes_reserved,
<------><------><------><------>  BTRFS_RESERVE_NO_FLUSH);
<------>if (ret)
<------><------>goto out;
<------>trace_btrfs_space_reservation(fs_info, "ino_cache", trans->transid,
<------><------><------><------>      trans->bytes_reserved, 1);
again:
<------>inode = lookup_free_ino_inode(root, path);
<------>if (IS_ERR(inode) && (PTR_ERR(inode) != -ENOENT || retry)) {
<------><------>ret = PTR_ERR(inode);
<------><------>goto out_release;
<------>}
 
<------>if (IS_ERR(inode)) {
<------><------>BUG_ON(retry); /* Logic error */
<------><------>retry = true;
 
<------><------>ret = create_free_ino_inode(root, trans, path);
<------><------>if (ret)
<------><------><------>goto out_release;
<------><------>goto again;
<------>}
 
<------>BTRFS_I(inode)->generation = 0;
<------>ret = btrfs_update_inode(trans, root, inode);
<------>if (ret) {
<------><------>btrfs_abort_transaction(trans, ret);
<------><------>goto out_put;
<------>}
 
<------>if (i_size_read(inode) > 0) {
<------><------>ret = btrfs_truncate_free_space_cache(trans, NULL, inode);
<------><------>if (ret) {
<------><------><------>if (ret != -ENOSPC)
<------><------><------><------>btrfs_abort_transaction(trans, ret);
<------><------><------>goto out_put;
<------><------>}
<------>}
 
<------>spin_lock(&root->ino_cache_lock);
<------>if (root->ino_cache_state != BTRFS_CACHE_FINISHED) {
<------><------>ret = -1;
<------><------>spin_unlock(&root->ino_cache_lock);
<------><------>goto out_put;
<------>}
<------>spin_unlock(&root->ino_cache_lock);
 
<------>spin_lock(&ctl->tree_lock);
<------>prealloc = sizeof(struct btrfs_free_space) * ctl->free_extents;
<------>prealloc = ALIGN(prealloc, PAGE_SIZE);
<------>prealloc += ctl->total_bitmaps * PAGE_SIZE;
<------>spin_unlock(&ctl->tree_lock);
 
<------>/* Just to make sure we have enough space */
<------>prealloc += 8 * PAGE_SIZE;
 
<------>ret = btrfs_delalloc_reserve_space(BTRFS_I(inode), &data_reserved, 0,
<------><------><------><------><------>   prealloc);
<------>if (ret)
<------><------>goto out_put;
 
<------>ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, prealloc,
<------><------><------><------><------>      prealloc, prealloc, &alloc_hint);
<------>if (ret) {
<------><------>btrfs_delalloc_release_extents(BTRFS_I(inode), prealloc);
<------><------>btrfs_delalloc_release_metadata(BTRFS_I(inode), prealloc, true);
<------><------>goto out_put;
<------>}
 
<------>ret = btrfs_write_out_ino_cache(root, trans, path, inode);
<------>btrfs_delalloc_release_extents(BTRFS_I(inode), prealloc);
out_put:
<------>iput(inode);
out_release:
<------>trace_btrfs_space_reservation(fs_info, "ino_cache", trans->transid,
<------><------><------><------>      trans->bytes_reserved, 0);
<------>btrfs_block_rsv_release(fs_info, trans->block_rsv,
<------><------><------><------>trans->bytes_reserved, NULL);
out:
<------>trans->block_rsv = rsv;
<------>trans->bytes_reserved = num_bytes;
 
<------>btrfs_free_path(path);
<------>extent_changeset_free(data_reserved);
<------>return ret;
}
 
int btrfs_find_highest_objectid(struct btrfs_root *root, u64 *objectid)
{
<------>struct btrfs_path *path;
<------>int ret;
<------>struct extent_buffer *l;
<------>struct btrfs_key search_key;
<------>struct btrfs_key found_key;
<------>int slot;
 
<------>path = btrfs_alloc_path();
<------>if (!path)
<------><------>return -ENOMEM;
 
<------>search_key.objectid = BTRFS_LAST_FREE_OBJECTID;
<------>search_key.type = -1;
<------>search_key.offset = (u64)-1;
<------>ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
<------>if (ret < 0)
<------><------>goto error;
<------>BUG_ON(ret == 0); /* Corruption */
<------>if (path->slots[0] > 0) {
<------><------>slot = path->slots[0] - 1;
<------><------>l = path->nodes[0];
<------><------>btrfs_item_key_to_cpu(l, &found_key, slot);
<------><------>*objectid = max_t(u64, found_key.objectid,
<------><------><------><------>  BTRFS_FIRST_FREE_OBJECTID - 1);
<------>} else {
<------><------>*objectid = BTRFS_FIRST_FREE_OBJECTID - 1;
<------>}
<------>ret = 0;
error:
<------>btrfs_free_path(path);
<------>return ret;
}
 
int btrfs_find_free_objectid(struct btrfs_root *root, u64 *objectid)
{
<------>int ret;
<------>mutex_lock(&root->objectid_mutex);
 
<------>if (unlikely(root->highest_objectid >= BTRFS_LAST_FREE_OBJECTID)) {
<------><------>btrfs_warn(root->fs_info,
<------><------><------>   "the objectid of root %llu reaches its highest value",
<------><------><------>   root->root_key.objectid);
<------><------>ret = -ENOSPC;
<------><------>goto out;
<------>}
 
<------>*objectid = ++root->highest_objectid;
<------>ret = 0;
out:
<------>mutex_unlock(&root->objectid_mutex);
<------>return ret;
}