+++ /dev/null
-// 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, BTRFS_I(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;
-}
git.samba.org / sfrench / cifs-2.6.git / blobdiff