[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/fs/btrfs/free-space-cache.c b/ap/os/linux/linux-3.4.x/fs/btrfs/free-space-cache.c
new file mode 100644
index 0000000..202008e
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/btrfs/free-space-cache.c
@@ -0,0 +1,2943 @@
+/*
+ * Copyright (C) 2008 Red Hat. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/pagemap.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/math64.h>
+#include <linux/ratelimit.h>
+#include "ctree.h"
+#include "free-space-cache.h"
+#include "transaction.h"
+#include "disk-io.h"
+#include "extent_io.h"
+#include "inode-map.h"
+
+#define BITS_PER_BITMAP (PAGE_CACHE_SIZE * 8)
+#define MAX_CACHE_BYTES_PER_GIG (32 * 1024)
+
+static int link_free_space(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info);
+
+static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 offset)
+{
+ struct btrfs_key key;
+ struct btrfs_key location;
+ struct btrfs_disk_key disk_key;
+ struct btrfs_free_space_header *header;
+ struct extent_buffer *leaf;
+ struct inode *inode = NULL;
+ int ret;
+
+ key.objectid = BTRFS_FREE_SPACE_OBJECTID;
+ key.offset = offset;
+ key.type = 0;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ if (ret > 0) {
+ btrfs_release_path(path);
+ return ERR_PTR(-ENOENT);
+ }
+
+ leaf = path->nodes[0];
+ header = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_free_space_header);
+ btrfs_free_space_key(leaf, header, &disk_key);
+ btrfs_disk_key_to_cpu(&location, &disk_key);
+ btrfs_release_path(path);
+
+ inode = btrfs_iget(root->fs_info->sb, &location, root, NULL);
+ if (!inode)
+ return ERR_PTR(-ENOENT);
+ if (IS_ERR(inode))
+ return inode;
+ if (is_bad_inode(inode)) {
+ iput(inode);
+ return ERR_PTR(-ENOENT);
+ }
+
+ inode->i_mapping->flags &= ~__GFP_FS;
+
+ return inode;
+}
+
+struct inode *lookup_free_space_inode(struct btrfs_root *root,
+ struct btrfs_block_group_cache
+ *block_group, struct btrfs_path *path)
+{
+ struct inode *inode = NULL;
+ u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
+
+ spin_lock(&block_group->lock);
+ if (block_group->inode)
+ inode = igrab(block_group->inode);
+ spin_unlock(&block_group->lock);
+ if (inode)
+ return inode;
+
+ inode = __lookup_free_space_inode(root, path,
+ block_group->key.objectid);
+ if (IS_ERR(inode))
+ return inode;
+
+ spin_lock(&block_group->lock);
+ if (!((BTRFS_I(inode)->flags & flags) == flags)) {
+ printk(KERN_INFO "Old style space inode found, converting.\n");
+ BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM |
+ BTRFS_INODE_NODATACOW;
+ block_group->disk_cache_state = BTRFS_DC_CLEAR;
+ }
+
+ if (!block_group->iref) {
+ block_group->inode = igrab(inode);
+ block_group->iref = 1;
+ }
+ spin_unlock(&block_group->lock);
+
+ return inode;
+}
+
+int __create_free_space_inode(struct btrfs_root *root,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_path *path, u64 ino, u64 offset)
+{
+ struct btrfs_key key;
+ struct btrfs_disk_key disk_key;
+ struct btrfs_free_space_header *header;
+ struct btrfs_inode_item *inode_item;
+ struct extent_buffer *leaf;
+ u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC;
+ int ret;
+
+ ret = btrfs_insert_empty_inode(trans, root, path, ino);
+ if (ret)
+ return ret;
+
+ /* We inline crc's for the free disk space cache */
+ if (ino != BTRFS_FREE_INO_OBJECTID)
+ flags |= BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
+
+ leaf = path->nodes[0];
+ inode_item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_inode_item);
+ btrfs_item_key(leaf, &disk_key, path->slots[0]);
+ memset_extent_buffer(leaf, 0, (unsigned long)inode_item,
+ sizeof(*inode_item));
+ btrfs_set_inode_generation(leaf, inode_item, trans->transid);
+ btrfs_set_inode_size(leaf, inode_item, 0);
+ btrfs_set_inode_nbytes(leaf, inode_item, 0);
+ btrfs_set_inode_uid(leaf, inode_item, 0);
+ btrfs_set_inode_gid(leaf, inode_item, 0);
+ btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
+ btrfs_set_inode_flags(leaf, inode_item, flags);
+ btrfs_set_inode_nlink(leaf, inode_item, 1);
+ btrfs_set_inode_transid(leaf, inode_item, trans->transid);
+ btrfs_set_inode_block_group(leaf, inode_item, offset);
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_release_path(path);
+
+ key.objectid = BTRFS_FREE_SPACE_OBJECTID;
+ key.offset = offset;
+ key.type = 0;
+
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ sizeof(struct btrfs_free_space_header));
+ if (ret < 0) {
+ btrfs_release_path(path);
+ return ret;
+ }
+ leaf = path->nodes[0];
+ header = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_free_space_header);
+ memset_extent_buffer(leaf, 0, (unsigned long)header, sizeof(*header));
+ btrfs_set_free_space_key(leaf, header, &disk_key);
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_release_path(path);
+
+ return 0;
+}
+
+int create_free_space_inode(struct btrfs_root *root,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_path *path)
+{
+ int ret;
+ u64 ino;
+
+ ret = btrfs_find_free_objectid(root, &ino);
+ if (ret < 0)
+ return ret;
+
+ return __create_free_space_inode(root, trans, path, ino,
+ block_group->key.objectid);
+}
+
+int btrfs_truncate_free_space_cache(struct btrfs_root *root,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_path *path,
+ struct inode *inode)
+{
+ struct btrfs_block_rsv *rsv;
+ u64 needed_bytes;
+ loff_t oldsize;
+ int ret = 0;
+
+ rsv = trans->block_rsv;
+ trans->block_rsv = &root->fs_info->global_block_rsv;
+
+ /* 1 for slack space, 1 for updating the inode */
+ needed_bytes = btrfs_calc_trunc_metadata_size(root, 1) +
+ btrfs_calc_trans_metadata_size(root, 1);
+
+ spin_lock(&trans->block_rsv->lock);
+ if (trans->block_rsv->reserved < needed_bytes) {
+ spin_unlock(&trans->block_rsv->lock);
+ trans->block_rsv = rsv;
+ return -ENOSPC;
+ }
+ spin_unlock(&trans->block_rsv->lock);
+
+ oldsize = i_size_read(inode);
+ btrfs_i_size_write(inode, 0);
+ truncate_pagecache(inode, oldsize, 0);
+
+ /*
+ * We don't need an orphan item because truncating the free space cache
+ * will never be split across transactions.
+ */
+ ret = btrfs_truncate_inode_items(trans, root, inode,
+ 0, BTRFS_EXTENT_DATA_KEY);
+
+ if (ret) {
+ trans->block_rsv = rsv;
+ btrfs_abort_transaction(trans, root, ret);
+ return ret;
+ }
+
+ ret = btrfs_update_inode(trans, root, inode);
+ if (ret)
+ btrfs_abort_transaction(trans, root, ret);
+ trans->block_rsv = rsv;
+
+ return ret;
+}
+
+static int readahead_cache(struct inode *inode)
+{
+ struct file_ra_state *ra;
+ unsigned long last_index;
+
+ ra = kzalloc(sizeof(*ra), GFP_NOFS);
+ if (!ra)
+ return -ENOMEM;
+
+ file_ra_state_init(ra, inode->i_mapping);
+ last_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT;
+
+ page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index);
+
+ kfree(ra);
+
+ return 0;
+}
+
+struct io_ctl {
+ void *cur, *orig;
+ struct page *page;
+ struct page **pages;
+ struct btrfs_root *root;
+ unsigned long size;
+ int index;
+ int num_pages;
+ unsigned check_crcs:1;
+};
+
+static int io_ctl_init(struct io_ctl *io_ctl, struct inode *inode,
+ struct btrfs_root *root)
+{
+ memset(io_ctl, 0, sizeof(struct io_ctl));
+ io_ctl->num_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
+ PAGE_CACHE_SHIFT;
+ io_ctl->pages = kzalloc(sizeof(struct page *) * io_ctl->num_pages,
+ GFP_NOFS);
+ if (!io_ctl->pages)
+ return -ENOMEM;
+ io_ctl->root = root;
+ if (btrfs_ino(inode) != BTRFS_FREE_INO_OBJECTID)
+ io_ctl->check_crcs = 1;
+ return 0;
+}
+
+static void io_ctl_free(struct io_ctl *io_ctl)
+{
+ kfree(io_ctl->pages);
+}
+
+static void io_ctl_unmap_page(struct io_ctl *io_ctl)
+{
+ if (io_ctl->cur) {
+ kunmap(io_ctl->page);
+ io_ctl->cur = NULL;
+ io_ctl->orig = NULL;
+ }
+}
+
+static void io_ctl_map_page(struct io_ctl *io_ctl, int clear)
+{
+ WARN_ON(io_ctl->cur);
+ BUG_ON(io_ctl->index >= io_ctl->num_pages);
+ io_ctl->page = io_ctl->pages[io_ctl->index++];
+ io_ctl->cur = kmap(io_ctl->page);
+ io_ctl->orig = io_ctl->cur;
+ io_ctl->size = PAGE_CACHE_SIZE;
+ if (clear)
+ memset(io_ctl->cur, 0, PAGE_CACHE_SIZE);
+}
+
+static void io_ctl_drop_pages(struct io_ctl *io_ctl)
+{
+ int i;
+
+ io_ctl_unmap_page(io_ctl);
+
+ for (i = 0; i < io_ctl->num_pages; i++) {
+ if (io_ctl->pages[i]) {
+ ClearPageChecked(io_ctl->pages[i]);
+ unlock_page(io_ctl->pages[i]);
+ page_cache_release(io_ctl->pages[i]);
+ }
+ }
+}
+
+static int io_ctl_prepare_pages(struct io_ctl *io_ctl, struct inode *inode,
+ int uptodate)
+{
+ struct page *page;
+ gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
+ int i;
+
+ for (i = 0; i < io_ctl->num_pages; i++) {
+ page = find_or_create_page(inode->i_mapping, i, mask);
+ if (!page) {
+ io_ctl_drop_pages(io_ctl);
+ return -ENOMEM;
+ }
+ io_ctl->pages[i] = page;
+ if (uptodate && !PageUptodate(page)) {
+ btrfs_readpage(NULL, page);
+ lock_page(page);
+ if (!PageUptodate(page)) {
+ printk(KERN_ERR "btrfs: error reading free "
+ "space cache\n");
+ io_ctl_drop_pages(io_ctl);
+ return -EIO;
+ }
+ }
+ }
+
+ for (i = 0; i < io_ctl->num_pages; i++) {
+ clear_page_dirty_for_io(io_ctl->pages[i]);
+ set_page_extent_mapped(io_ctl->pages[i]);
+ }
+
+ return 0;
+}
+
+static void io_ctl_set_generation(struct io_ctl *io_ctl, u64 generation)
+{
+ u64 *val;
+
+ io_ctl_map_page(io_ctl, 1);
+
+ /*
+ * Skip the csum areas. If we don't check crcs then we just have a
+ * 64bit chunk at the front of the first page.
+ */
+ if (io_ctl->check_crcs) {
+ io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
+ io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
+ } else {
+ io_ctl->cur += sizeof(u64);
+ io_ctl->size -= sizeof(u64) * 2;
+ }
+
+ val = io_ctl->cur;
+ *val = cpu_to_le64(generation);
+ io_ctl->cur += sizeof(u64);
+}
+
+static int io_ctl_check_generation(struct io_ctl *io_ctl, u64 generation)
+{
+ u64 *gen;
+
+ /*
+ * Skip the crc area. If we don't check crcs then we just have a 64bit
+ * chunk at the front of the first page.
+ */
+ if (io_ctl->check_crcs) {
+ io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
+ io_ctl->size -= sizeof(u64) +
+ (sizeof(u32) * io_ctl->num_pages);
+ } else {
+ io_ctl->cur += sizeof(u64);
+ io_ctl->size -= sizeof(u64) * 2;
+ }
+
+ gen = io_ctl->cur;
+ if (le64_to_cpu(*gen) != generation) {
+ printk_ratelimited(KERN_ERR "btrfs: space cache generation "
+ "(%Lu) does not match inode (%Lu)\n", *gen,
+ generation);
+ io_ctl_unmap_page(io_ctl);
+ return -EIO;
+ }
+ io_ctl->cur += sizeof(u64);
+ return 0;
+}
+
+static void io_ctl_set_crc(struct io_ctl *io_ctl, int index)
+{
+ u32 *tmp;
+ u32 crc = ~(u32)0;
+ unsigned offset = 0;
+
+ if (!io_ctl->check_crcs) {
+ io_ctl_unmap_page(io_ctl);
+ return;
+ }
+
+ if (index == 0)
+ offset = sizeof(u32) * io_ctl->num_pages;
+
+ crc = btrfs_csum_data(io_ctl->root, io_ctl->orig + offset, crc,
+ PAGE_CACHE_SIZE - offset);
+ btrfs_csum_final(crc, (char *)&crc);
+ io_ctl_unmap_page(io_ctl);
+ tmp = kmap(io_ctl->pages[0]);
+ tmp += index;
+ *tmp = crc;
+ kunmap(io_ctl->pages[0]);
+}
+
+static int io_ctl_check_crc(struct io_ctl *io_ctl, int index)
+{
+ u32 *tmp, val;
+ u32 crc = ~(u32)0;
+ unsigned offset = 0;
+
+ if (!io_ctl->check_crcs) {
+ io_ctl_map_page(io_ctl, 0);
+ return 0;
+ }
+
+ if (index == 0)
+ offset = sizeof(u32) * io_ctl->num_pages;
+
+ tmp = kmap(io_ctl->pages[0]);
+ tmp += index;
+ val = *tmp;
+ kunmap(io_ctl->pages[0]);
+
+ io_ctl_map_page(io_ctl, 0);
+ crc = btrfs_csum_data(io_ctl->root, io_ctl->orig + offset, crc,
+ PAGE_CACHE_SIZE - offset);
+ btrfs_csum_final(crc, (char *)&crc);
+ if (val != crc) {
+ printk_ratelimited(KERN_ERR "btrfs: csum mismatch on free "
+ "space cache\n");
+ io_ctl_unmap_page(io_ctl);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int io_ctl_add_entry(struct io_ctl *io_ctl, u64 offset, u64 bytes,
+ void *bitmap)
+{
+ struct btrfs_free_space_entry *entry;
+
+ if (!io_ctl->cur)
+ return -ENOSPC;
+
+ entry = io_ctl->cur;
+ entry->offset = cpu_to_le64(offset);
+ entry->bytes = cpu_to_le64(bytes);
+ entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
+ BTRFS_FREE_SPACE_EXTENT;
+ io_ctl->cur += sizeof(struct btrfs_free_space_entry);
+ io_ctl->size -= sizeof(struct btrfs_free_space_entry);
+
+ if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
+ return 0;
+
+ io_ctl_set_crc(io_ctl, io_ctl->index - 1);
+
+ /* No more pages to map */
+ if (io_ctl->index >= io_ctl->num_pages)
+ return 0;
+
+ /* map the next page */
+ io_ctl_map_page(io_ctl, 1);
+ return 0;
+}
+
+static int io_ctl_add_bitmap(struct io_ctl *io_ctl, void *bitmap)
+{
+ if (!io_ctl->cur)
+ return -ENOSPC;
+
+ /*
+ * If we aren't at the start of the current page, unmap this one and
+ * map the next one if there is any left.
+ */
+ if (io_ctl->cur != io_ctl->orig) {
+ io_ctl_set_crc(io_ctl, io_ctl->index - 1);
+ if (io_ctl->index >= io_ctl->num_pages)
+ return -ENOSPC;
+ io_ctl_map_page(io_ctl, 0);
+ }
+
+ memcpy(io_ctl->cur, bitmap, PAGE_CACHE_SIZE);
+ io_ctl_set_crc(io_ctl, io_ctl->index - 1);
+ if (io_ctl->index < io_ctl->num_pages)
+ io_ctl_map_page(io_ctl, 0);
+ return 0;
+}
+
+static void io_ctl_zero_remaining_pages(struct io_ctl *io_ctl)
+{
+ /*
+ * If we're not on the boundary we know we've modified the page and we
+ * need to crc the page.
+ */
+ if (io_ctl->cur != io_ctl->orig)
+ io_ctl_set_crc(io_ctl, io_ctl->index - 1);
+ else
+ io_ctl_unmap_page(io_ctl);
+
+ while (io_ctl->index < io_ctl->num_pages) {
+ io_ctl_map_page(io_ctl, 1);
+ io_ctl_set_crc(io_ctl, io_ctl->index - 1);
+ }
+}
+
+static int io_ctl_read_entry(struct io_ctl *io_ctl,
+ struct btrfs_free_space *entry, u8 *type)
+{
+ struct btrfs_free_space_entry *e;
+ int ret;
+
+ if (!io_ctl->cur) {
+ ret = io_ctl_check_crc(io_ctl, io_ctl->index);
+ if (ret)
+ return ret;
+ }
+
+ e = io_ctl->cur;
+ entry->offset = le64_to_cpu(e->offset);
+ entry->bytes = le64_to_cpu(e->bytes);
+ *type = e->type;
+ io_ctl->cur += sizeof(struct btrfs_free_space_entry);
+ io_ctl->size -= sizeof(struct btrfs_free_space_entry);
+
+ if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
+ return 0;
+
+ io_ctl_unmap_page(io_ctl);
+
+ return 0;
+}
+
+static int io_ctl_read_bitmap(struct io_ctl *io_ctl,
+ struct btrfs_free_space *entry)
+{
+ int ret;
+
+ ret = io_ctl_check_crc(io_ctl, io_ctl->index);
+ if (ret)
+ return ret;
+
+ memcpy(entry->bitmap, io_ctl->cur, PAGE_CACHE_SIZE);
+ io_ctl_unmap_page(io_ctl);
+
+ return 0;
+}
+
+int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
+ struct btrfs_free_space_ctl *ctl,
+ struct btrfs_path *path, u64 offset)
+{
+ struct btrfs_free_space_header *header;
+ struct extent_buffer *leaf;
+ struct io_ctl io_ctl;
+ struct btrfs_key key;
+ struct btrfs_free_space *e, *n;
+ struct list_head bitmaps;
+ u64 num_entries;
+ u64 num_bitmaps;
+ u64 generation;
+ u8 type;
+ int ret = 0;
+
+ INIT_LIST_HEAD(&bitmaps);
+
+ /* Nothing in the space cache, goodbye */
+ if (!i_size_read(inode))
+ return 0;
+
+ key.objectid = BTRFS_FREE_SPACE_OBJECTID;
+ key.offset = offset;
+ key.type = 0;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ return 0;
+ else if (ret > 0) {
+ btrfs_release_path(path);
+ return 0;
+ }
+
+ ret = -1;
+
+ leaf = path->nodes[0];
+ header = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_free_space_header);
+ num_entries = btrfs_free_space_entries(leaf, header);
+ num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
+ generation = btrfs_free_space_generation(leaf, header);
+ btrfs_release_path(path);
+
+ if (BTRFS_I(inode)->generation != generation) {
+ printk(KERN_ERR "btrfs: free space inode generation (%llu) did"
+ " not match free space cache generation (%llu)\n",
+ (unsigned long long)BTRFS_I(inode)->generation,
+ (unsigned long long)generation);
+ return 0;
+ }
+
+ if (!num_entries)
+ return 0;
+
+ ret = io_ctl_init(&io_ctl, inode, root);
+ if (ret)
+ return ret;
+
+ ret = readahead_cache(inode);
+ if (ret)
+ goto out;
+
+ ret = io_ctl_prepare_pages(&io_ctl, inode, 1);
+ if (ret)
+ goto out;
+
+ ret = io_ctl_check_crc(&io_ctl, 0);
+ if (ret)
+ goto free_cache;
+
+ ret = io_ctl_check_generation(&io_ctl, generation);
+ if (ret)
+ goto free_cache;
+
+ while (num_entries) {
+ e = kmem_cache_zalloc(btrfs_free_space_cachep,
+ GFP_NOFS);
+ if (!e)
+ goto free_cache;
+
+ ret = io_ctl_read_entry(&io_ctl, e, &type);
+ if (ret) {
+ kmem_cache_free(btrfs_free_space_cachep, e);
+ goto free_cache;
+ }
+
+ if (!e->bytes) {
+ kmem_cache_free(btrfs_free_space_cachep, e);
+ goto free_cache;
+ }
+
+ if (type == BTRFS_FREE_SPACE_EXTENT) {
+ spin_lock(&ctl->tree_lock);
+ ret = link_free_space(ctl, e);
+ spin_unlock(&ctl->tree_lock);
+ if (ret) {
+ printk(KERN_ERR "Duplicate entries in "
+ "free space cache, dumping\n");
+ kmem_cache_free(btrfs_free_space_cachep, e);
+ goto free_cache;
+ }
+ } else {
+ BUG_ON(!num_bitmaps);
+ num_bitmaps--;
+ e->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
+ if (!e->bitmap) {
+ kmem_cache_free(
+ btrfs_free_space_cachep, e);
+ goto free_cache;
+ }
+ spin_lock(&ctl->tree_lock);
+ ret = link_free_space(ctl, e);
+ ctl->total_bitmaps++;
+ ctl->op->recalc_thresholds(ctl);
+ spin_unlock(&ctl->tree_lock);
+ if (ret) {
+ printk(KERN_ERR "Duplicate entries in "
+ "free space cache, dumping\n");
+ kmem_cache_free(btrfs_free_space_cachep, e);
+ goto free_cache;
+ }
+ list_add_tail(&e->list, &bitmaps);
+ }
+
+ num_entries--;
+ }
+
+ io_ctl_unmap_page(&io_ctl);
+
+ /*
+ * We add the bitmaps at the end of the entries in order that
+ * the bitmap entries are added to the cache.
+ */
+ list_for_each_entry_safe(e, n, &bitmaps, list) {
+ list_del_init(&e->list);
+ ret = io_ctl_read_bitmap(&io_ctl, e);
+ if (ret)
+ goto free_cache;
+ }
+
+ io_ctl_drop_pages(&io_ctl);
+ ret = 1;
+out:
+ io_ctl_free(&io_ctl);
+ return ret;
+free_cache:
+ io_ctl_drop_pages(&io_ctl);
+ __btrfs_remove_free_space_cache(ctl);
+ goto out;
+}
+
+int load_free_space_cache(struct btrfs_fs_info *fs_info,
+ struct btrfs_block_group_cache *block_group)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_root *root = fs_info->tree_root;
+ struct inode *inode;
+ struct btrfs_path *path;
+ int ret = 0;
+ bool matched;
+ u64 used = btrfs_block_group_used(&block_group->item);
+
+ /*
+ * If this block group has been marked to be cleared for one reason or
+ * another then we can't trust the on disk cache, so just return.
+ */
+ spin_lock(&block_group->lock);
+ if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
+ spin_unlock(&block_group->lock);
+ return 0;
+ }
+ spin_unlock(&block_group->lock);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return 0;
+ path->search_commit_root = 1;
+ path->skip_locking = 1;
+
+ inode = lookup_free_space_inode(root, block_group, path);
+ if (IS_ERR(inode)) {
+ btrfs_free_path(path);
+ return 0;
+ }
+
+ /* We may have converted the inode and made the cache invalid. */
+ spin_lock(&block_group->lock);
+ if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
+ spin_unlock(&block_group->lock);
+ btrfs_free_path(path);
+ goto out;
+ }
+ spin_unlock(&block_group->lock);
+
+ ret = __load_free_space_cache(fs_info->tree_root, inode, ctl,
+ path, block_group->key.objectid);
+ btrfs_free_path(path);
+ if (ret <= 0)
+ goto out;
+
+ spin_lock(&ctl->tree_lock);
+ matched = (ctl->free_space == (block_group->key.offset - used -
+ block_group->bytes_super));
+ spin_unlock(&ctl->tree_lock);
+
+ if (!matched) {
+ __btrfs_remove_free_space_cache(ctl);
+ printk(KERN_ERR "block group %llu has an wrong amount of free "
+ "space\n", block_group->key.objectid);
+ ret = -1;
+ }
+out:
+ if (ret < 0) {
+ /* This cache is bogus, make sure it gets cleared */
+ spin_lock(&block_group->lock);
+ block_group->disk_cache_state = BTRFS_DC_CLEAR;
+ spin_unlock(&block_group->lock);
+ ret = 0;
+
+ printk(KERN_ERR "btrfs: failed to load free space cache "
+ "for block group %llu\n", block_group->key.objectid);
+ }
+
+ iput(inode);
+ return ret;
+}
+
+/**
+ * __btrfs_write_out_cache - write out cached info to an inode
+ * @root - the root the inode belongs to
+ * @ctl - the free space cache we are going to write out
+ * @block_group - the block_group for this cache if it belongs to a block_group
+ * @trans - the trans handle
+ * @path - the path to use
+ * @offset - the offset for the key we'll insert
+ *
+ * This function writes out a free space cache struct to disk for quick recovery
+ * on mount. This will return 0 if it was successfull in writing the cache out,
+ * and -1 if it was not.
+ */
+int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
+ struct btrfs_free_space_ctl *ctl,
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_path *path, u64 offset)
+{
+ struct btrfs_free_space_header *header;
+ struct extent_buffer *leaf;
+ struct rb_node *node;
+ struct list_head *pos, *n;
+ struct extent_state *cached_state = NULL;
+ struct btrfs_free_cluster *cluster = NULL;
+ struct extent_io_tree *unpin = NULL;
+ struct io_ctl io_ctl;
+ struct list_head bitmap_list;
+ struct btrfs_key key;
+ u64 start, extent_start, extent_end, len;
+ int entries = 0;
+ int bitmaps = 0;
+ int ret;
+ int err = -1;
+
+ INIT_LIST_HEAD(&bitmap_list);
+
+ if (!i_size_read(inode))
+ return -1;
+
+ ret = io_ctl_init(&io_ctl, inode, root);
+ if (ret)
+ return -1;
+
+ /* Get the cluster for this block_group if it exists */
+ if (block_group && !list_empty(&block_group->cluster_list))
+ cluster = list_entry(block_group->cluster_list.next,
+ struct btrfs_free_cluster,
+ block_group_list);
+
+ /* Lock all pages first so we can lock the extent safely. */
+ io_ctl_prepare_pages(&io_ctl, inode, 0);
+
+ lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
+ 0, &cached_state);
+
+ node = rb_first(&ctl->free_space_offset);
+ if (!node && cluster) {
+ node = rb_first(&cluster->root);
+ cluster = NULL;
+ }
+
+ /* Make sure we can fit our crcs into the first page */
+ if (io_ctl.check_crcs &&
+ (io_ctl.num_pages * sizeof(u32)) >= PAGE_CACHE_SIZE) {
+ WARN_ON(1);
+ goto out_nospc;
+ }
+
+ io_ctl_set_generation(&io_ctl, trans->transid);
+
+ /* Write out the extent entries */
+ while (node) {
+ struct btrfs_free_space *e;
+
+ e = rb_entry(node, struct btrfs_free_space, offset_index);
+ entries++;
+
+ ret = io_ctl_add_entry(&io_ctl, e->offset, e->bytes,
+ e->bitmap);
+ if (ret)
+ goto out_nospc;
+
+ if (e->bitmap) {
+ list_add_tail(&e->list, &bitmap_list);
+ bitmaps++;
+ }
+ node = rb_next(node);
+ if (!node && cluster) {
+ node = rb_first(&cluster->root);
+ cluster = NULL;
+ }
+ }
+
+ /*
+ * We want to add any pinned extents to our free space cache
+ * so we don't leak the space
+ */
+
+ /*
+ * We shouldn't have switched the pinned extents yet so this is the
+ * right one
+ */
+ unpin = root->fs_info->pinned_extents;
+
+ if (block_group)
+ start = block_group->key.objectid;
+
+ while (block_group && (start < block_group->key.objectid +
+ block_group->key.offset)) {
+ ret = find_first_extent_bit(unpin, start,
+ &extent_start, &extent_end,
+ EXTENT_DIRTY);
+ if (ret) {
+ ret = 0;
+ break;
+ }
+
+ /* This pinned extent is out of our range */
+ if (extent_start >= block_group->key.objectid +
+ block_group->key.offset)
+ break;
+
+ extent_start = max(extent_start, start);
+ extent_end = min(block_group->key.objectid +
+ block_group->key.offset, extent_end + 1);
+ len = extent_end - extent_start;
+
+ entries++;
+ ret = io_ctl_add_entry(&io_ctl, extent_start, len, NULL);
+ if (ret)
+ goto out_nospc;
+
+ start = extent_end;
+ }
+
+ /* Write out the bitmaps */
+ list_for_each_safe(pos, n, &bitmap_list) {
+ struct btrfs_free_space *entry =
+ list_entry(pos, struct btrfs_free_space, list);
+
+ ret = io_ctl_add_bitmap(&io_ctl, entry->bitmap);
+ if (ret)
+ goto out_nospc;
+ list_del_init(&entry->list);
+ }
+
+ /* Zero out the rest of the pages just to make sure */
+ io_ctl_zero_remaining_pages(&io_ctl);
+
+ ret = btrfs_dirty_pages(root, inode, io_ctl.pages, io_ctl.num_pages,
+ 0, i_size_read(inode), &cached_state);
+ io_ctl_drop_pages(&io_ctl);
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
+ i_size_read(inode) - 1, &cached_state, GFP_NOFS);
+
+ if (ret)
+ goto out;
+
+
+ ret = filemap_write_and_wait(inode->i_mapping);
+ if (ret)
+ goto out;
+
+ key.objectid = BTRFS_FREE_SPACE_OBJECTID;
+ key.offset = offset;
+ key.type = 0;
+
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+ if (ret < 0) {
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
+ EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL,
+ GFP_NOFS);
+ goto out;
+ }
+ leaf = path->nodes[0];
+ if (ret > 0) {
+ struct btrfs_key found_key;
+ BUG_ON(!path->slots[0]);
+ path->slots[0]--;
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
+ found_key.offset != offset) {
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
+ inode->i_size - 1,
+ EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0,
+ NULL, GFP_NOFS);
+ btrfs_release_path(path);
+ goto out;
+ }
+ }
+
+ BTRFS_I(inode)->generation = trans->transid;
+ header = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_free_space_header);
+ btrfs_set_free_space_entries(leaf, header, entries);
+ btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
+ btrfs_set_free_space_generation(leaf, header, trans->transid);
+ btrfs_mark_buffer_dirty(leaf);
+ btrfs_release_path(path);
+
+ err = 0;
+out:
+ io_ctl_free(&io_ctl);
+ if (err) {
+ invalidate_inode_pages2(inode->i_mapping);
+ BTRFS_I(inode)->generation = 0;
+ }
+ btrfs_update_inode(trans, root, inode);
+ return err;
+
+out_nospc:
+ list_for_each_safe(pos, n, &bitmap_list) {
+ struct btrfs_free_space *entry =
+ list_entry(pos, struct btrfs_free_space, list);
+ list_del_init(&entry->list);
+ }
+ io_ctl_drop_pages(&io_ctl);
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
+ i_size_read(inode) - 1, &cached_state, GFP_NOFS);
+ goto out;
+}
+
+int btrfs_write_out_cache(struct btrfs_root *root,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_path *path)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct inode *inode;
+ int ret = 0;
+
+ root = root->fs_info->tree_root;
+
+ spin_lock(&block_group->lock);
+ if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
+ spin_unlock(&block_group->lock);
+ return 0;
+ }
+ spin_unlock(&block_group->lock);
+
+ inode = lookup_free_space_inode(root, block_group, path);
+ if (IS_ERR(inode))
+ return 0;
+
+ ret = __btrfs_write_out_cache(root, inode, ctl, block_group, trans,
+ path, block_group->key.objectid);
+ if (ret) {
+ spin_lock(&block_group->lock);
+ block_group->disk_cache_state = BTRFS_DC_ERROR;
+ spin_unlock(&block_group->lock);
+ ret = 0;
+#ifdef DEBUG
+ printk(KERN_ERR "btrfs: failed to write free space cache "
+ "for block group %llu\n", block_group->key.objectid);
+#endif
+ }
+
+ iput(inode);
+ return ret;
+}
+
+static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
+ u64 offset)
+{
+ BUG_ON(offset < bitmap_start);
+ offset -= bitmap_start;
+ return (unsigned long)(div_u64(offset, unit));
+}
+
+static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
+{
+ return (unsigned long)(div_u64(bytes, unit));
+}
+
+static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
+ u64 offset)
+{
+ u64 bitmap_start;
+ u64 bytes_per_bitmap;
+
+ bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
+ bitmap_start = offset - ctl->start;
+ bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
+ bitmap_start *= bytes_per_bitmap;
+ bitmap_start += ctl->start;
+
+ return bitmap_start;
+}
+
+static int tree_insert_offset(struct rb_root *root, u64 offset,
+ struct rb_node *node, int bitmap)
+{
+ struct rb_node **p = &root->rb_node;
+ struct rb_node *parent = NULL;
+ struct btrfs_free_space *info;
+
+ while (*p) {
+ parent = *p;
+ info = rb_entry(parent, struct btrfs_free_space, offset_index);
+
+ if (offset < info->offset) {
+ p = &(*p)->rb_left;
+ } else if (offset > info->offset) {
+ p = &(*p)->rb_right;
+ } else {
+ /*
+ * we could have a bitmap entry and an extent entry
+ * share the same offset. If this is the case, we want
+ * the extent entry to always be found first if we do a
+ * linear search through the tree, since we want to have
+ * the quickest allocation time, and allocating from an
+ * extent is faster than allocating from a bitmap. So
+ * if we're inserting a bitmap and we find an entry at
+ * this offset, we want to go right, or after this entry
+ * logically. If we are inserting an extent and we've
+ * found a bitmap, we want to go left, or before
+ * logically.
+ */
+ if (bitmap) {
+ if (info->bitmap) {
+ WARN_ON_ONCE(1);
+ return -EEXIST;
+ }
+ p = &(*p)->rb_right;
+ } else {
+ if (!info->bitmap) {
+ WARN_ON_ONCE(1);
+ return -EEXIST;
+ }
+ p = &(*p)->rb_left;
+ }
+ }
+ }
+
+ rb_link_node(node, parent, p);
+ rb_insert_color(node, root);
+
+ return 0;
+}
+
+/*
+ * searches the tree for the given offset.
+ *
+ * fuzzy - If this is set, then we are trying to make an allocation, and we just
+ * want a section that has at least bytes size and comes at or after the given
+ * offset.
+ */
+static struct btrfs_free_space *
+tree_search_offset(struct btrfs_free_space_ctl *ctl,
+ u64 offset, int bitmap_only, int fuzzy)
+{
+ struct rb_node *n = ctl->free_space_offset.rb_node;
+ struct btrfs_free_space *entry, *prev = NULL;
+
+ /* find entry that is closest to the 'offset' */
+ while (1) {
+ if (!n) {
+ entry = NULL;
+ break;
+ }
+
+ entry = rb_entry(n, struct btrfs_free_space, offset_index);
+ prev = entry;
+
+ if (offset < entry->offset)
+ n = n->rb_left;
+ else if (offset > entry->offset)
+ n = n->rb_right;
+ else
+ break;
+ }
+
+ if (bitmap_only) {
+ if (!entry)
+ return NULL;
+ if (entry->bitmap)
+ return entry;
+
+ /*
+ * bitmap entry and extent entry may share same offset,
+ * in that case, bitmap entry comes after extent entry.
+ */
+ n = rb_next(n);
+ if (!n)
+ return NULL;
+ entry = rb_entry(n, struct btrfs_free_space, offset_index);
+ if (entry->offset != offset)
+ return NULL;
+
+ WARN_ON(!entry->bitmap);
+ return entry;
+ } else if (entry) {
+ if (entry->bitmap) {
+ /*
+ * if previous extent entry covers the offset,
+ * we should return it instead of the bitmap entry
+ */
+ n = &entry->offset_index;
+ while (1) {
+ n = rb_prev(n);
+ if (!n)
+ break;
+ prev = rb_entry(n, struct btrfs_free_space,
+ offset_index);
+ if (!prev->bitmap) {
+ if (prev->offset + prev->bytes > offset)
+ entry = prev;
+ break;
+ }
+ }
+ }
+ return entry;
+ }
+
+ if (!prev)
+ return NULL;
+
+ /* find last entry before the 'offset' */
+ entry = prev;
+ if (entry->offset > offset) {
+ n = rb_prev(&entry->offset_index);
+ if (n) {
+ entry = rb_entry(n, struct btrfs_free_space,
+ offset_index);
+ BUG_ON(entry->offset > offset);
+ } else {
+ if (fuzzy)
+ return entry;
+ else
+ return NULL;
+ }
+ }
+
+ if (entry->bitmap) {
+ n = &entry->offset_index;
+ while (1) {
+ n = rb_prev(n);
+ if (!n)
+ break;
+ prev = rb_entry(n, struct btrfs_free_space,
+ offset_index);
+ if (!prev->bitmap) {
+ if (prev->offset + prev->bytes > offset)
+ return prev;
+ break;
+ }
+ }
+ if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
+ return entry;
+ } else if (entry->offset + entry->bytes > offset)
+ return entry;
+
+ if (!fuzzy)
+ return NULL;
+
+ while (1) {
+ if (entry->bitmap) {
+ if (entry->offset + BITS_PER_BITMAP *
+ ctl->unit > offset)
+ break;
+ } else {
+ if (entry->offset + entry->bytes > offset)
+ break;
+ }
+
+ n = rb_next(&entry->offset_index);
+ if (!n)
+ return NULL;
+ entry = rb_entry(n, struct btrfs_free_space, offset_index);
+ }
+ return entry;
+}
+
+static inline void
+__unlink_free_space(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info)
+{
+ rb_erase(&info->offset_index, &ctl->free_space_offset);
+ ctl->free_extents--;
+}
+
+static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info)
+{
+ __unlink_free_space(ctl, info);
+ ctl->free_space -= info->bytes;
+}
+
+static int link_free_space(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info)
+{
+ int ret = 0;
+
+ BUG_ON(!info->bitmap && !info->bytes);
+ ret = tree_insert_offset(&ctl->free_space_offset, info->offset,
+ &info->offset_index, (info->bitmap != NULL));
+ if (ret)
+ return ret;
+
+ ctl->free_space += info->bytes;
+ ctl->free_extents++;
+ return ret;
+}
+
+static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
+{
+ struct btrfs_block_group_cache *block_group = ctl->private;
+ u64 max_bytes;
+ u64 bitmap_bytes;
+ u64 extent_bytes;
+ u64 size = block_group->key.offset;
+ u64 bytes_per_bg = BITS_PER_BITMAP * block_group->sectorsize;
+ int max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);
+
+ BUG_ON(ctl->total_bitmaps > max_bitmaps);
+
+ /*
+ * The goal is to keep the total amount of memory used per 1gb of space
+ * at or below 32k, so we need to adjust how much memory we allow to be
+ * used by extent based free space tracking
+ */
+ if (size < 1024 * 1024 * 1024)
+ max_bytes = MAX_CACHE_BYTES_PER_GIG;
+ else
+ max_bytes = MAX_CACHE_BYTES_PER_GIG *
+ div64_u64(size, 1024 * 1024 * 1024);
+
+ /*
+ * we want to account for 1 more bitmap than what we have so we can make
+ * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as
+ * we add more bitmaps.
+ */
+ bitmap_bytes = (ctl->total_bitmaps + 1) * PAGE_CACHE_SIZE;
+
+ if (bitmap_bytes >= max_bytes) {
+ ctl->extents_thresh = 0;
+ return;
+ }
+
+ /*
+ * we want the extent entry threshold to always be at most 1/2 the maxw
+ * bytes we can have, or whatever is less than that.
+ */
+ extent_bytes = max_bytes - bitmap_bytes;
+ extent_bytes = min_t(u64, extent_bytes, div64_u64(max_bytes, 2));
+
+ ctl->extents_thresh =
+ div64_u64(extent_bytes, (sizeof(struct btrfs_free_space)));
+}
+
+static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info,
+ u64 offset, u64 bytes)
+{
+ unsigned long start, count;
+
+ start = offset_to_bit(info->offset, ctl->unit, offset);
+ count = bytes_to_bits(bytes, ctl->unit);
+ BUG_ON(start + count > BITS_PER_BITMAP);
+
+ bitmap_clear(info->bitmap, start, count);
+
+ info->bytes -= bytes;
+}
+
+static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info, u64 offset,
+ u64 bytes)
+{
+ __bitmap_clear_bits(ctl, info, offset, bytes);
+ ctl->free_space -= bytes;
+}
+
+static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info, u64 offset,
+ u64 bytes)
+{
+ unsigned long start, count;
+
+ start = offset_to_bit(info->offset, ctl->unit, offset);
+ count = bytes_to_bits(bytes, ctl->unit);
+ BUG_ON(start + count > BITS_PER_BITMAP);
+
+ bitmap_set(info->bitmap, start, count);
+
+ info->bytes += bytes;
+ ctl->free_space += bytes;
+}
+
+static int search_bitmap(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *bitmap_info, u64 *offset,
+ u64 *bytes)
+{
+ unsigned long found_bits = 0;
+ unsigned long bits, i;
+ unsigned long next_zero;
+
+ i = offset_to_bit(bitmap_info->offset, ctl->unit,
+ max_t(u64, *offset, bitmap_info->offset));
+ bits = bytes_to_bits(*bytes, ctl->unit);
+
+ for (i = find_next_bit(bitmap_info->bitmap, BITS_PER_BITMAP, i);
+ i < BITS_PER_BITMAP;
+ i = find_next_bit(bitmap_info->bitmap, BITS_PER_BITMAP, i + 1)) {
+ next_zero = find_next_zero_bit(bitmap_info->bitmap,
+ BITS_PER_BITMAP, i);
+ if ((next_zero - i) >= bits) {
+ found_bits = next_zero - i;
+ break;
+ }
+ i = next_zero;
+ }
+
+ if (found_bits) {
+ *offset = (u64)(i * ctl->unit) + bitmap_info->offset;
+ *bytes = (u64)(found_bits) * ctl->unit;
+ return 0;
+ }
+
+ return -1;
+}
+
+static struct btrfs_free_space *
+find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes)
+{
+ struct btrfs_free_space *entry;
+ struct rb_node *node;
+ int ret;
+
+ if (!ctl->free_space_offset.rb_node)
+ return NULL;
+
+ entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1);
+ if (!entry)
+ return NULL;
+
+ for (node = &entry->offset_index; node; node = rb_next(node)) {
+ entry = rb_entry(node, struct btrfs_free_space, offset_index);
+ if (entry->bytes < *bytes)
+ continue;
+
+ if (entry->bitmap) {
+ ret = search_bitmap(ctl, entry, offset, bytes);
+ if (!ret)
+ return entry;
+ continue;
+ }
+
+ *offset = entry->offset;
+ *bytes = entry->bytes;
+ return entry;
+ }
+
+ return NULL;
+}
+
+static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info, u64 offset)
+{
+ info->offset = offset_to_bitmap(ctl, offset);
+ info->bytes = 0;
+ INIT_LIST_HEAD(&info->list);
+ link_free_space(ctl, info);
+ ctl->total_bitmaps++;
+
+ ctl->op->recalc_thresholds(ctl);
+}
+
+static void free_bitmap(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *bitmap_info)
+{
+ unlink_free_space(ctl, bitmap_info);
+ kfree(bitmap_info->bitmap);
+ kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
+ ctl->total_bitmaps--;
+ ctl->op->recalc_thresholds(ctl);
+}
+
+static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *bitmap_info,
+ u64 *offset, u64 *bytes)
+{
+ u64 end;
+ u64 search_start, search_bytes;
+ int ret;
+
+again:
+ end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
+
+ /*
+ * XXX - this can go away after a few releases.
+ *
+ * since the only user of btrfs_remove_free_space is the tree logging
+ * stuff, and the only way to test that is under crash conditions, we
+ * want to have this debug stuff here just in case somethings not
+ * working. Search the bitmap for the space we are trying to use to
+ * make sure its actually there. If its not there then we need to stop
+ * because something has gone wrong.
+ */
+ search_start = *offset;
+ search_bytes = *bytes;
+ search_bytes = min(search_bytes, end - search_start + 1);
+ ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes);
+ BUG_ON(ret < 0 || search_start != *offset);
+
+ if (*offset > bitmap_info->offset && *offset + *bytes > end) {
+ bitmap_clear_bits(ctl, bitmap_info, *offset, end - *offset + 1);
+ *bytes -= end - *offset + 1;
+ *offset = end + 1;
+ } else if (*offset >= bitmap_info->offset && *offset + *bytes <= end) {
+ bitmap_clear_bits(ctl, bitmap_info, *offset, *bytes);
+ *bytes = 0;
+ }
+
+ if (*bytes) {
+ struct rb_node *next = rb_next(&bitmap_info->offset_index);
+ if (!bitmap_info->bytes)
+ free_bitmap(ctl, bitmap_info);
+
+ /*
+ * no entry after this bitmap, but we still have bytes to
+ * remove, so something has gone wrong.
+ */
+ if (!next)
+ return -EINVAL;
+
+ bitmap_info = rb_entry(next, struct btrfs_free_space,
+ offset_index);
+
+ /*
+ * if the next entry isn't a bitmap we need to return to let the
+ * extent stuff do its work.
+ */
+ if (!bitmap_info->bitmap)
+ return -EAGAIN;
+
+ /*
+ * Ok the next item is a bitmap, but it may not actually hold
+ * the information for the rest of this free space stuff, so
+ * look for it, and if we don't find it return so we can try
+ * everything over again.
+ */
+ search_start = *offset;
+ search_bytes = *bytes;
+ ret = search_bitmap(ctl, bitmap_info, &search_start,
+ &search_bytes);
+ if (ret < 0 || search_start != *offset)
+ return -EAGAIN;
+
+ goto again;
+ } else if (!bitmap_info->bytes)
+ free_bitmap(ctl, bitmap_info);
+
+ return 0;
+}
+
+static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info, u64 offset,
+ u64 bytes)
+{
+ u64 bytes_to_set = 0;
+ u64 end;
+
+ end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
+
+ bytes_to_set = min(end - offset, bytes);
+
+ bitmap_set_bits(ctl, info, offset, bytes_to_set);
+
+ return bytes_to_set;
+
+}
+
+static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info)
+{
+ struct btrfs_block_group_cache *block_group = ctl->private;
+
+ /*
+ * If we are below the extents threshold then we can add this as an
+ * extent, and don't have to deal with the bitmap
+ */
+ if (ctl->free_extents < ctl->extents_thresh) {
+ /*
+ * If this block group has some small extents we don't want to
+ * use up all of our free slots in the cache with them, we want
+ * to reserve them to larger extents, however if we have plent
+ * of cache left then go ahead an dadd them, no sense in adding
+ * the overhead of a bitmap if we don't have to.
+ */
+ if (info->bytes <= block_group->sectorsize * 4) {
+ if (ctl->free_extents * 2 <= ctl->extents_thresh)
+ return false;
+ } else {
+ return false;
+ }
+ }
+
+ /*
+ * some block groups are so tiny they can't be enveloped by a bitmap, so
+ * don't even bother to create a bitmap for this
+ */
+ if (BITS_PER_BITMAP * block_group->sectorsize >
+ block_group->key.offset)
+ return false;
+
+ return true;
+}
+
+static struct btrfs_free_space_op free_space_op = {
+ .recalc_thresholds = recalculate_thresholds,
+ .use_bitmap = use_bitmap,
+};
+
+static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info)
+{
+ struct btrfs_free_space *bitmap_info;
+ struct btrfs_block_group_cache *block_group = NULL;
+ int added = 0;
+ u64 bytes, offset, bytes_added;
+ int ret;
+
+ bytes = info->bytes;
+ offset = info->offset;
+
+ if (!ctl->op->use_bitmap(ctl, info))
+ return 0;
+
+ if (ctl->op == &free_space_op)
+ block_group = ctl->private;
+again:
+ /*
+ * Since we link bitmaps right into the cluster we need to see if we
+ * have a cluster here, and if so and it has our bitmap we need to add
+ * the free space to that bitmap.
+ */
+ if (block_group && !list_empty(&block_group->cluster_list)) {
+ struct btrfs_free_cluster *cluster;
+ struct rb_node *node;
+ struct btrfs_free_space *entry;
+
+ cluster = list_entry(block_group->cluster_list.next,
+ struct btrfs_free_cluster,
+ block_group_list);
+ spin_lock(&cluster->lock);
+ node = rb_first(&cluster->root);
+ if (!node) {
+ spin_unlock(&cluster->lock);
+ goto no_cluster_bitmap;
+ }
+
+ entry = rb_entry(node, struct btrfs_free_space, offset_index);
+ if (!entry->bitmap) {
+ spin_unlock(&cluster->lock);
+ goto no_cluster_bitmap;
+ }
+
+ if (entry->offset == offset_to_bitmap(ctl, offset)) {
+ bytes_added = add_bytes_to_bitmap(ctl, entry,
+ offset, bytes);
+ bytes -= bytes_added;
+ offset += bytes_added;
+ }
+ spin_unlock(&cluster->lock);
+ if (!bytes) {
+ ret = 1;
+ goto out;
+ }
+ }
+
+no_cluster_bitmap:
+ bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
+ 1, 0);
+ if (!bitmap_info) {
+ BUG_ON(added);
+ goto new_bitmap;
+ }
+
+ bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
+ bytes -= bytes_added;
+ offset += bytes_added;
+ added = 0;
+
+ if (!bytes) {
+ ret = 1;
+ goto out;
+ } else
+ goto again;
+
+new_bitmap:
+ if (info && info->bitmap) {
+ add_new_bitmap(ctl, info, offset);
+ added = 1;
+ info = NULL;
+ goto again;
+ } else {
+ spin_unlock(&ctl->tree_lock);
+
+ /* no pre-allocated info, allocate a new one */
+ if (!info) {
+ info = kmem_cache_zalloc(btrfs_free_space_cachep,
+ GFP_NOFS);
+ if (!info) {
+ spin_lock(&ctl->tree_lock);
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+
+ /* allocate the bitmap */
+ info->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
+ spin_lock(&ctl->tree_lock);
+ if (!info->bitmap) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ goto again;
+ }
+
+out:
+ if (info) {
+ if (info->bitmap)
+ kfree(info->bitmap);
+ kmem_cache_free(btrfs_free_space_cachep, info);
+ }
+
+ return ret;
+}
+
+static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
+ struct btrfs_free_space *info, bool update_stat)
+{
+ struct btrfs_free_space *left_info;
+ struct btrfs_free_space *right_info;
+ bool merged = false;
+ u64 offset = info->offset;
+ u64 bytes = info->bytes;
+
+ /*
+ * first we want to see if there is free space adjacent to the range we
+ * are adding, if there is remove that struct and add a new one to
+ * cover the entire range
+ */
+ right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
+ if (right_info && rb_prev(&right_info->offset_index))
+ left_info = rb_entry(rb_prev(&right_info->offset_index),
+ struct btrfs_free_space, offset_index);
+ else
+ left_info = tree_search_offset(ctl, offset - 1, 0, 0);
+
+ if (right_info && !right_info->bitmap) {
+ if (update_stat)
+ unlink_free_space(ctl, right_info);
+ else
+ __unlink_free_space(ctl, right_info);
+ info->bytes += right_info->bytes;
+ kmem_cache_free(btrfs_free_space_cachep, right_info);
+ merged = true;
+ }
+
+ if (left_info && !left_info->bitmap &&
+ left_info->offset + left_info->bytes == offset) {
+ if (update_stat)
+ unlink_free_space(ctl, left_info);
+ else
+ __unlink_free_space(ctl, left_info);
+ info->offset = left_info->offset;
+ info->bytes += left_info->bytes;
+ kmem_cache_free(btrfs_free_space_cachep, left_info);
+ merged = true;
+ }
+
+ return merged;
+}
+
+int __btrfs_add_free_space(struct btrfs_free_space_ctl *ctl,
+ u64 offset, u64 bytes)
+{
+ struct btrfs_free_space *info;
+ int ret = 0;
+
+ info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
+ if (!info)
+ return -ENOMEM;
+
+ info->offset = offset;
+ info->bytes = bytes;
+
+ spin_lock(&ctl->tree_lock);
+
+ if (try_merge_free_space(ctl, info, true))
+ goto link;
+
+ /*
+ * There was no extent directly to the left or right of this new
+ * extent then we know we're going to have to allocate a new extent, so
+ * before we do that see if we need to drop this into a bitmap
+ */
+ ret = insert_into_bitmap(ctl, info);
+ if (ret < 0) {
+ goto out;
+ } else if (ret) {
+ ret = 0;
+ goto out;
+ }
+link:
+ ret = link_free_space(ctl, info);
+ if (ret)
+ kmem_cache_free(btrfs_free_space_cachep, info);
+out:
+ spin_unlock(&ctl->tree_lock);
+
+ if (ret) {
+ printk(KERN_CRIT "btrfs: unable to add free space :%d\n", ret);
+ BUG_ON(ret == -EEXIST);
+ }
+
+ return ret;
+}
+
+int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
+ u64 offset, u64 bytes)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *info;
+ struct btrfs_free_space *next_info = NULL;
+ int ret = 0;
+
+ spin_lock(&ctl->tree_lock);
+
+again:
+ info = tree_search_offset(ctl, offset, 0, 0);
+ if (!info) {
+ /*
+ * oops didn't find an extent that matched the space we wanted
+ * to remove, look for a bitmap instead
+ */
+ info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
+ 1, 0);
+ if (!info) {
+ /* the tree logging code might be calling us before we
+ * have fully loaded the free space rbtree for this
+ * block group. So it is possible the entry won't
+ * be in the rbtree yet at all. The caching code
+ * will make sure not to put it in the rbtree if
+ * the logging code has pinned it.
+ */
+ goto out_lock;
+ }
+ }
+
+ if (info->bytes < bytes && rb_next(&info->offset_index)) {
+ u64 end;
+ next_info = rb_entry(rb_next(&info->offset_index),
+ struct btrfs_free_space,
+ offset_index);
+
+ if (next_info->bitmap)
+ end = next_info->offset +
+ BITS_PER_BITMAP * ctl->unit - 1;
+ else
+ end = next_info->offset + next_info->bytes;
+
+ if (next_info->bytes < bytes ||
+ next_info->offset > offset || offset > end) {
+ printk(KERN_CRIT "Found free space at %llu, size %llu,"
+ " trying to use %llu\n",
+ (unsigned long long)info->offset,
+ (unsigned long long)info->bytes,
+ (unsigned long long)bytes);
+ WARN_ON(1);
+ ret = -EINVAL;
+ goto out_lock;
+ }
+
+ info = next_info;
+ }
+
+ if (info->bytes == bytes) {
+ unlink_free_space(ctl, info);
+ if (info->bitmap) {
+ kfree(info->bitmap);
+ ctl->total_bitmaps--;
+ }
+ kmem_cache_free(btrfs_free_space_cachep, info);
+ ret = 0;
+ goto out_lock;
+ }
+
+ if (!info->bitmap && info->offset == offset) {
+ unlink_free_space(ctl, info);
+ info->offset += bytes;
+ info->bytes -= bytes;
+ ret = link_free_space(ctl, info);
+ WARN_ON(ret);
+ goto out_lock;
+ }
+
+ if (!info->bitmap && info->offset <= offset &&
+ info->offset + info->bytes >= offset + bytes) {
+ u64 old_start = info->offset;
+ /*
+ * we're freeing space in the middle of the info,
+ * this can happen during tree log replay
+ *
+ * first unlink the old info and then
+ * insert it again after the hole we're creating
+ */
+ unlink_free_space(ctl, info);
+ if (offset + bytes < info->offset + info->bytes) {
+ u64 old_end = info->offset + info->bytes;
+
+ info->offset = offset + bytes;
+ info->bytes = old_end - info->offset;
+ ret = link_free_space(ctl, info);
+ WARN_ON(ret);
+ if (ret)
+ goto out_lock;
+ } else {
+ /* the hole we're creating ends at the end
+ * of the info struct, just free the info
+ */
+ kmem_cache_free(btrfs_free_space_cachep, info);
+ }
+ spin_unlock(&ctl->tree_lock);
+
+ /* step two, insert a new info struct to cover
+ * anything before the hole
+ */
+ ret = btrfs_add_free_space(block_group, old_start,
+ offset - old_start);
+ WARN_ON(ret); /* -ENOMEM */
+ goto out;
+ }
+
+ ret = remove_from_bitmap(ctl, info, &offset, &bytes);
+ if (ret == -EAGAIN)
+ goto again;
+ BUG_ON(ret); /* logic error */
+out_lock:
+ spin_unlock(&ctl->tree_lock);
+out:
+ return ret;
+}
+
+void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
+ u64 bytes)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *info;
+ struct rb_node *n;
+ int count = 0;
+
+ for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
+ info = rb_entry(n, struct btrfs_free_space, offset_index);
+ if (info->bytes >= bytes)
+ count++;
+ printk(KERN_CRIT "entry offset %llu, bytes %llu, bitmap %s\n",
+ (unsigned long long)info->offset,
+ (unsigned long long)info->bytes,
+ (info->bitmap) ? "yes" : "no");
+ }
+ printk(KERN_INFO "block group has cluster?: %s\n",
+ list_empty(&block_group->cluster_list) ? "no" : "yes");
+ printk(KERN_INFO "%d blocks of free space at or bigger than bytes is"
+ "\n", count);
+}
+
+void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+
+ spin_lock_init(&ctl->tree_lock);
+ ctl->unit = block_group->sectorsize;
+ ctl->start = block_group->key.objectid;
+ ctl->private = block_group;
+ ctl->op = &free_space_op;
+
+ /*
+ * we only want to have 32k of ram per block group for keeping
+ * track of free space, and if we pass 1/2 of that we want to
+ * start converting things over to using bitmaps
+ */
+ ctl->extents_thresh = ((1024 * 32) / 2) /
+ sizeof(struct btrfs_free_space);
+}
+
+/*
+ * for a given cluster, put all of its extents back into the free
+ * space cache. If the block group passed doesn't match the block group
+ * pointed to by the cluster, someone else raced in and freed the
+ * cluster already. In that case, we just return without changing anything
+ */
+static int
+__btrfs_return_cluster_to_free_space(
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_cluster *cluster)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *entry;
+ struct rb_node *node;
+
+ spin_lock(&cluster->lock);
+ if (cluster->block_group != block_group)
+ goto out;
+
+ cluster->block_group = NULL;
+ cluster->window_start = 0;
+ list_del_init(&cluster->block_group_list);
+
+ node = rb_first(&cluster->root);
+ while (node) {
+ bool bitmap;
+
+ entry = rb_entry(node, struct btrfs_free_space, offset_index);
+ node = rb_next(&entry->offset_index);
+ rb_erase(&entry->offset_index, &cluster->root);
+
+ bitmap = (entry->bitmap != NULL);
+ if (!bitmap)
+ try_merge_free_space(ctl, entry, false);
+ tree_insert_offset(&ctl->free_space_offset,
+ entry->offset, &entry->offset_index, bitmap);
+ }
+ cluster->root = RB_ROOT;
+
+out:
+ spin_unlock(&cluster->lock);
+ btrfs_put_block_group(block_group);
+ return 0;
+}
+
+void __btrfs_remove_free_space_cache_locked(struct btrfs_free_space_ctl *ctl)
+{
+ struct btrfs_free_space *info;
+ struct rb_node *node;
+
+ while ((node = rb_last(&ctl->free_space_offset)) != NULL) {
+ info = rb_entry(node, struct btrfs_free_space, offset_index);
+ if (!info->bitmap) {
+ unlink_free_space(ctl, info);
+ kmem_cache_free(btrfs_free_space_cachep, info);
+ } else {
+ free_bitmap(ctl, info);
+ }
+ if (need_resched()) {
+ spin_unlock(&ctl->tree_lock);
+ cond_resched();
+ spin_lock(&ctl->tree_lock);
+ }
+ }
+}
+
+void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl)
+{
+ spin_lock(&ctl->tree_lock);
+ __btrfs_remove_free_space_cache_locked(ctl);
+ spin_unlock(&ctl->tree_lock);
+}
+
+void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_cluster *cluster;
+ struct list_head *head;
+
+ spin_lock(&ctl->tree_lock);
+ while ((head = block_group->cluster_list.next) !=
+ &block_group->cluster_list) {
+ cluster = list_entry(head, struct btrfs_free_cluster,
+ block_group_list);
+
+ WARN_ON(cluster->block_group != block_group);
+ __btrfs_return_cluster_to_free_space(block_group, cluster);
+ if (need_resched()) {
+ spin_unlock(&ctl->tree_lock);
+ cond_resched();
+ spin_lock(&ctl->tree_lock);
+ }
+ }
+ __btrfs_remove_free_space_cache_locked(ctl);
+ spin_unlock(&ctl->tree_lock);
+
+}
+
+u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
+ u64 offset, u64 bytes, u64 empty_size)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *entry = NULL;
+ u64 bytes_search = bytes + empty_size;
+ u64 ret = 0;
+
+ spin_lock(&ctl->tree_lock);
+ entry = find_free_space(ctl, &offset, &bytes_search);
+ if (!entry)
+ goto out;
+
+ ret = offset;
+ if (entry->bitmap) {
+ bitmap_clear_bits(ctl, entry, offset, bytes);
+ if (!entry->bytes)
+ free_bitmap(ctl, entry);
+ } else {
+ unlink_free_space(ctl, entry);
+ entry->offset += bytes;
+ entry->bytes -= bytes;
+ if (!entry->bytes)
+ kmem_cache_free(btrfs_free_space_cachep, entry);
+ else
+ link_free_space(ctl, entry);
+ }
+
+out:
+ spin_unlock(&ctl->tree_lock);
+
+ return ret;
+}
+
+/*
+ * given a cluster, put all of its extents back into the free space
+ * cache. If a block group is passed, this function will only free
+ * a cluster that belongs to the passed block group.
+ *
+ * Otherwise, it'll get a reference on the block group pointed to by the
+ * cluster and remove the cluster from it.
+ */
+int btrfs_return_cluster_to_free_space(
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_cluster *cluster)
+{
+ struct btrfs_free_space_ctl *ctl;
+ int ret;
+
+ /* first, get a safe pointer to the block group */
+ spin_lock(&cluster->lock);
+ if (!block_group) {
+ block_group = cluster->block_group;
+ if (!block_group) {
+ spin_unlock(&cluster->lock);
+ return 0;
+ }
+ } else if (cluster->block_group != block_group) {
+ /* someone else has already freed it don't redo their work */
+ spin_unlock(&cluster->lock);
+ return 0;
+ }
+ atomic_inc(&block_group->count);
+ spin_unlock(&cluster->lock);
+
+ ctl = block_group->free_space_ctl;
+
+ /* now return any extents the cluster had on it */
+ spin_lock(&ctl->tree_lock);
+ ret = __btrfs_return_cluster_to_free_space(block_group, cluster);
+ spin_unlock(&ctl->tree_lock);
+
+ /* finally drop our ref */
+ btrfs_put_block_group(block_group);
+ return ret;
+}
+
+static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_cluster *cluster,
+ struct btrfs_free_space *entry,
+ u64 bytes, u64 min_start)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ int err;
+ u64 search_start = cluster->window_start;
+ u64 search_bytes = bytes;
+ u64 ret = 0;
+
+ search_start = min_start;
+ search_bytes = bytes;
+
+ err = search_bitmap(ctl, entry, &search_start, &search_bytes);
+ if (err)
+ return 0;
+
+ ret = search_start;
+ __bitmap_clear_bits(ctl, entry, ret, bytes);
+
+ return ret;
+}
+
+/*
+ * given a cluster, try to allocate 'bytes' from it, returns 0
+ * if it couldn't find anything suitably large, or a logical disk offset
+ * if things worked out
+ */
+u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_cluster *cluster, u64 bytes,
+ u64 min_start)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *entry = NULL;
+ struct rb_node *node;
+ u64 ret = 0;
+
+ spin_lock(&cluster->lock);
+ if (bytes > cluster->max_size)
+ goto out;
+
+ if (cluster->block_group != block_group)
+ goto out;
+
+ node = rb_first(&cluster->root);
+ if (!node)
+ goto out;
+
+ entry = rb_entry(node, struct btrfs_free_space, offset_index);
+ while(1) {
+ if (entry->bytes < bytes ||
+ (!entry->bitmap && entry->offset < min_start)) {
+ node = rb_next(&entry->offset_index);
+ if (!node)
+ break;
+ entry = rb_entry(node, struct btrfs_free_space,
+ offset_index);
+ continue;
+ }
+
+ if (entry->bitmap) {
+ ret = btrfs_alloc_from_bitmap(block_group,
+ cluster, entry, bytes,
+ cluster->window_start);
+ if (ret == 0) {
+ node = rb_next(&entry->offset_index);
+ if (!node)
+ break;
+ entry = rb_entry(node, struct btrfs_free_space,
+ offset_index);
+ continue;
+ }
+ cluster->window_start += bytes;
+ } else {
+ ret = entry->offset;
+
+ entry->offset += bytes;
+ entry->bytes -= bytes;
+ }
+
+ if (entry->bytes == 0)
+ rb_erase(&entry->offset_index, &cluster->root);
+ break;
+ }
+out:
+ spin_unlock(&cluster->lock);
+
+ if (!ret)
+ return 0;
+
+ spin_lock(&ctl->tree_lock);
+
+ ctl->free_space -= bytes;
+ if (entry->bytes == 0) {
+ ctl->free_extents--;
+ if (entry->bitmap) {
+ kfree(entry->bitmap);
+ ctl->total_bitmaps--;
+ ctl->op->recalc_thresholds(ctl);
+ }
+ kmem_cache_free(btrfs_free_space_cachep, entry);
+ }
+
+ spin_unlock(&ctl->tree_lock);
+
+ return ret;
+}
+
+static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_space *entry,
+ struct btrfs_free_cluster *cluster,
+ u64 offset, u64 bytes,
+ u64 cont1_bytes, u64 min_bytes)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ unsigned long next_zero;
+ unsigned long i;
+ unsigned long want_bits;
+ unsigned long min_bits;
+ unsigned long found_bits;
+ unsigned long start = 0;
+ unsigned long total_found = 0;
+ int ret;
+
+ i = offset_to_bit(entry->offset, block_group->sectorsize,
+ max_t(u64, offset, entry->offset));
+ want_bits = bytes_to_bits(bytes, block_group->sectorsize);
+ min_bits = bytes_to_bits(min_bytes, block_group->sectorsize);
+
+again:
+ found_bits = 0;
+ for (i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, i);
+ i < BITS_PER_BITMAP;
+ i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, i + 1)) {
+ next_zero = find_next_zero_bit(entry->bitmap,
+ BITS_PER_BITMAP, i);
+ if (next_zero - i >= min_bits) {
+ found_bits = next_zero - i;
+ break;
+ }
+ i = next_zero;
+ }
+
+ if (!found_bits)
+ return -ENOSPC;
+
+ if (!total_found) {
+ start = i;
+ cluster->max_size = 0;
+ }
+
+ total_found += found_bits;
+
+ if (cluster->max_size < found_bits * block_group->sectorsize)
+ cluster->max_size = found_bits * block_group->sectorsize;
+
+ if (total_found < want_bits || cluster->max_size < cont1_bytes) {
+ i = next_zero + 1;
+ goto again;
+ }
+
+ cluster->window_start = start * block_group->sectorsize +
+ entry->offset;
+ rb_erase(&entry->offset_index, &ctl->free_space_offset);
+ ret = tree_insert_offset(&cluster->root, entry->offset,
+ &entry->offset_index, 1);
+ BUG_ON(ret); /* -EEXIST; Logic error */
+
+ trace_btrfs_setup_cluster(block_group, cluster,
+ total_found * block_group->sectorsize, 1);
+ return 0;
+}
+
+/*
+ * This searches the block group for just extents to fill the cluster with.
+ * Try to find a cluster with at least bytes total bytes, at least one
+ * extent of cont1_bytes, and other clusters of at least min_bytes.
+ */
+static noinline int
+setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_cluster *cluster,
+ struct list_head *bitmaps, u64 offset, u64 bytes,
+ u64 cont1_bytes, u64 min_bytes)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *first = NULL;
+ struct btrfs_free_space *entry = NULL;
+ struct btrfs_free_space *last;
+ struct rb_node *node;
+ u64 window_start;
+ u64 window_free;
+ u64 max_extent;
+ u64 total_size = 0;
+
+ entry = tree_search_offset(ctl, offset, 0, 1);
+ if (!entry)
+ return -ENOSPC;
+
+ /*
+ * We don't want bitmaps, so just move along until we find a normal
+ * extent entry.
+ */
+ while (entry->bitmap || entry->bytes < min_bytes) {
+ if (entry->bitmap && list_empty(&entry->list))
+ list_add_tail(&entry->list, bitmaps);
+ node = rb_next(&entry->offset_index);
+ if (!node)
+ return -ENOSPC;
+ entry = rb_entry(node, struct btrfs_free_space, offset_index);
+ }
+
+ window_start = entry->offset;
+ window_free = entry->bytes;
+ max_extent = entry->bytes;
+ first = entry;
+ last = entry;
+
+ for (node = rb_next(&entry->offset_index); node;
+ node = rb_next(&entry->offset_index)) {
+ entry = rb_entry(node, struct btrfs_free_space, offset_index);
+
+ if (entry->bitmap) {
+ if (list_empty(&entry->list))
+ list_add_tail(&entry->list, bitmaps);
+ continue;
+ }
+
+ if (entry->bytes < min_bytes)
+ continue;
+
+ last = entry;
+ window_free += entry->bytes;
+ if (entry->bytes > max_extent)
+ max_extent = entry->bytes;
+ }
+
+ if (window_free < bytes || max_extent < cont1_bytes)
+ return -ENOSPC;
+
+ cluster->window_start = first->offset;
+
+ node = &first->offset_index;
+
+ /*
+ * now we've found our entries, pull them out of the free space
+ * cache and put them into the cluster rbtree
+ */
+ do {
+ int ret;
+
+ entry = rb_entry(node, struct btrfs_free_space, offset_index);
+ node = rb_next(&entry->offset_index);
+ if (entry->bitmap || entry->bytes < min_bytes)
+ continue;
+
+ rb_erase(&entry->offset_index, &ctl->free_space_offset);
+ ret = tree_insert_offset(&cluster->root, entry->offset,
+ &entry->offset_index, 0);
+ total_size += entry->bytes;
+ BUG_ON(ret); /* -EEXIST; Logic error */
+ } while (node && entry != last);
+
+ cluster->max_size = max_extent;
+ trace_btrfs_setup_cluster(block_group, cluster, total_size, 0);
+ return 0;
+}
+
+/*
+ * This specifically looks for bitmaps that may work in the cluster, we assume
+ * that we have already failed to find extents that will work.
+ */
+static noinline int
+setup_cluster_bitmap(struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_cluster *cluster,
+ struct list_head *bitmaps, u64 offset, u64 bytes,
+ u64 cont1_bytes, u64 min_bytes)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *entry;
+ int ret = -ENOSPC;
+ u64 bitmap_offset = offset_to_bitmap(ctl, offset);
+
+ if (ctl->total_bitmaps == 0)
+ return -ENOSPC;
+
+ /*
+ * The bitmap that covers offset won't be in the list unless offset
+ * is just its start offset.
+ */
+ entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
+ if (entry->offset != bitmap_offset) {
+ entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
+ if (entry && list_empty(&entry->list))
+ list_add(&entry->list, bitmaps);
+ }
+
+ list_for_each_entry(entry, bitmaps, list) {
+ if (entry->bytes < bytes)
+ continue;
+ ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
+ bytes, cont1_bytes, min_bytes);
+ if (!ret)
+ return 0;
+ }
+
+ /*
+ * The bitmaps list has all the bitmaps that record free space
+ * starting after offset, so no more search is required.
+ */
+ return -ENOSPC;
+}
+
+/*
+ * here we try to find a cluster of blocks in a block group. The goal
+ * is to find at least bytes+empty_size.
+ * We might not find them all in one contiguous area.
+ *
+ * returns zero and sets up cluster if things worked out, otherwise
+ * it returns -enospc
+ */
+int btrfs_find_space_cluster(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_block_group_cache *block_group,
+ struct btrfs_free_cluster *cluster,
+ u64 offset, u64 bytes, u64 empty_size)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *entry, *tmp;
+ LIST_HEAD(bitmaps);
+ u64 min_bytes;
+ u64 cont1_bytes;
+ int ret;
+
+ /*
+ * Choose the minimum extent size we'll require for this
+ * cluster. For SSD_SPREAD, don't allow any fragmentation.
+ * For metadata, allow allocates with smaller extents. For
+ * data, keep it dense.
+ */
+ if (btrfs_test_opt(root, SSD_SPREAD)) {
+ cont1_bytes = min_bytes = bytes + empty_size;
+ } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
+ cont1_bytes = bytes;
+ min_bytes = block_group->sectorsize;
+ } else {
+ cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
+ min_bytes = block_group->sectorsize;
+ }
+
+ spin_lock(&ctl->tree_lock);
+
+ /*
+ * If we know we don't have enough space to make a cluster don't even
+ * bother doing all the work to try and find one.
+ */
+ if (ctl->free_space < bytes) {
+ spin_unlock(&ctl->tree_lock);
+ return -ENOSPC;
+ }
+
+ spin_lock(&cluster->lock);
+
+ /* someone already found a cluster, hooray */
+ if (cluster->block_group) {
+ ret = 0;
+ goto out;
+ }
+
+ trace_btrfs_find_cluster(block_group, offset, bytes, empty_size,
+ min_bytes);
+
+ INIT_LIST_HEAD(&bitmaps);
+ ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
+ bytes + empty_size,
+ cont1_bytes, min_bytes);
+ if (ret)
+ ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
+ offset, bytes + empty_size,
+ cont1_bytes, min_bytes);
+
+ /* Clear our temporary list */
+ list_for_each_entry_safe(entry, tmp, &bitmaps, list)
+ list_del_init(&entry->list);
+
+ if (!ret) {
+ atomic_inc(&block_group->count);
+ list_add_tail(&cluster->block_group_list,
+ &block_group->cluster_list);
+ cluster->block_group = block_group;
+ } else {
+ trace_btrfs_failed_cluster_setup(block_group);
+ }
+out:
+ spin_unlock(&cluster->lock);
+ spin_unlock(&ctl->tree_lock);
+
+ return ret;
+}
+
+/*
+ * simple code to zero out a cluster
+ */
+void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
+{
+ spin_lock_init(&cluster->lock);
+ spin_lock_init(&cluster->refill_lock);
+ cluster->root = RB_ROOT;
+ cluster->max_size = 0;
+ INIT_LIST_HEAD(&cluster->block_group_list);
+ cluster->block_group = NULL;
+}
+
+static int do_trimming(struct btrfs_block_group_cache *block_group,
+ u64 *total_trimmed, u64 start, u64 bytes,
+ u64 reserved_start, u64 reserved_bytes)
+{
+ struct btrfs_space_info *space_info = block_group->space_info;
+ struct btrfs_fs_info *fs_info = block_group->fs_info;
+ int ret;
+ int update = 0;
+ u64 trimmed = 0;
+
+ spin_lock(&space_info->lock);
+ spin_lock(&block_group->lock);
+ if (!block_group->ro) {
+ block_group->reserved += reserved_bytes;
+ space_info->bytes_reserved += reserved_bytes;
+ update = 1;
+ }
+ spin_unlock(&block_group->lock);
+ spin_unlock(&space_info->lock);
+
+ ret = btrfs_error_discard_extent(fs_info->extent_root,
+ start, bytes, &trimmed);
+ if (!ret)
+ *total_trimmed += trimmed;
+
+ btrfs_add_free_space(block_group, reserved_start, reserved_bytes);
+
+ if (update) {
+ spin_lock(&space_info->lock);
+ spin_lock(&block_group->lock);
+ if (block_group->ro)
+ space_info->bytes_readonly += reserved_bytes;
+ block_group->reserved -= reserved_bytes;
+ space_info->bytes_reserved -= reserved_bytes;
+ spin_unlock(&space_info->lock);
+ spin_unlock(&block_group->lock);
+ }
+
+ return ret;
+}
+
+static int trim_no_bitmap(struct btrfs_block_group_cache *block_group,
+ u64 *total_trimmed, u64 start, u64 end, u64 minlen)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *entry;
+ struct rb_node *node;
+ int ret = 0;
+ u64 extent_start;
+ u64 extent_bytes;
+ u64 bytes;
+
+ while (start < end) {
+ spin_lock(&ctl->tree_lock);
+
+ if (ctl->free_space < minlen) {
+ spin_unlock(&ctl->tree_lock);
+ break;
+ }
+
+ entry = tree_search_offset(ctl, start, 0, 1);
+ if (!entry) {
+ spin_unlock(&ctl->tree_lock);
+ break;
+ }
+
+ /* skip bitmaps */
+ while (entry->bitmap) {
+ node = rb_next(&entry->offset_index);
+ if (!node) {
+ spin_unlock(&ctl->tree_lock);
+ goto out;
+ }
+ entry = rb_entry(node, struct btrfs_free_space,
+ offset_index);
+ }
+
+ if (entry->offset >= end) {
+ spin_unlock(&ctl->tree_lock);
+ break;
+ }
+
+ extent_start = entry->offset;
+ extent_bytes = entry->bytes;
+ start = max(start, extent_start);
+ bytes = min(extent_start + extent_bytes, end) - start;
+ if (bytes < minlen) {
+ spin_unlock(&ctl->tree_lock);
+ goto next;
+ }
+
+ unlink_free_space(ctl, entry);
+ kmem_cache_free(btrfs_free_space_cachep, entry);
+
+ spin_unlock(&ctl->tree_lock);
+
+ ret = do_trimming(block_group, total_trimmed, start, bytes,
+ extent_start, extent_bytes);
+ if (ret)
+ break;
+next:
+ start += bytes;
+
+ if (fatal_signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+
+ cond_resched();
+ }
+out:
+ return ret;
+}
+
+static int trim_bitmaps(struct btrfs_block_group_cache *block_group,
+ u64 *total_trimmed, u64 start, u64 end, u64 minlen)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *entry;
+ int ret = 0;
+ int ret2;
+ u64 bytes;
+ u64 offset = offset_to_bitmap(ctl, start);
+
+ while (offset < end) {
+ bool next_bitmap = false;
+
+ spin_lock(&ctl->tree_lock);
+
+ if (ctl->free_space < minlen) {
+ spin_unlock(&ctl->tree_lock);
+ break;
+ }
+
+ entry = tree_search_offset(ctl, offset, 1, 0);
+ if (!entry) {
+ spin_unlock(&ctl->tree_lock);
+ next_bitmap = true;
+ goto next;
+ }
+
+ bytes = minlen;
+ ret2 = search_bitmap(ctl, entry, &start, &bytes);
+ if (ret2 || start >= end) {
+ spin_unlock(&ctl->tree_lock);
+ next_bitmap = true;
+ goto next;
+ }
+
+ bytes = min(bytes, end - start);
+ if (bytes < minlen) {
+ spin_unlock(&ctl->tree_lock);
+ goto next;
+ }
+
+ bitmap_clear_bits(ctl, entry, start, bytes);
+ if (entry->bytes == 0)
+ free_bitmap(ctl, entry);
+
+ spin_unlock(&ctl->tree_lock);
+
+ ret = do_trimming(block_group, total_trimmed, start, bytes,
+ start, bytes);
+ if (ret)
+ break;
+next:
+ if (next_bitmap) {
+ offset += BITS_PER_BITMAP * ctl->unit;
+ } else {
+ start += bytes;
+ if (start >= offset + BITS_PER_BITMAP * ctl->unit)
+ offset += BITS_PER_BITMAP * ctl->unit;
+ }
+
+ if (fatal_signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+
+ cond_resched();
+ }
+
+ return ret;
+}
+
+int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
+ u64 *trimmed, u64 start, u64 end, u64 minlen)
+{
+ int ret;
+
+ *trimmed = 0;
+
+ ret = trim_no_bitmap(block_group, trimmed, start, end, minlen);
+ if (ret)
+ return ret;
+
+ ret = trim_bitmaps(block_group, trimmed, start, end, minlen);
+
+ return ret;
+}
+
+/*
+ * Find the left-most item in the cache tree, and then return the
+ * smallest inode number in the item.
+ *
+ * Note: the returned inode number may not be the smallest one in
+ * the tree, if the left-most item is a bitmap.
+ */
+u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root)
+{
+ struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl;
+ struct btrfs_free_space *entry = NULL;
+ u64 ino = 0;
+
+ spin_lock(&ctl->tree_lock);
+
+ if (RB_EMPTY_ROOT(&ctl->free_space_offset))
+ goto out;
+
+ entry = rb_entry(rb_first(&ctl->free_space_offset),
+ struct btrfs_free_space, offset_index);
+
+ if (!entry->bitmap) {
+ ino = entry->offset;
+
+ unlink_free_space(ctl, entry);
+ entry->offset++;
+ entry->bytes--;
+ if (!entry->bytes)
+ kmem_cache_free(btrfs_free_space_cachep, entry);
+ else
+ link_free_space(ctl, entry);
+ } else {
+ u64 offset = 0;
+ u64 count = 1;
+ int ret;
+
+ ret = search_bitmap(ctl, entry, &offset, &count);
+ /* Logic error; Should be empty if it can't find anything */
+ BUG_ON(ret);
+
+ ino = offset;
+ bitmap_clear_bits(ctl, entry, offset, 1);
+ if (entry->bytes == 0)
+ free_bitmap(ctl, entry);
+ }
+out:
+ spin_unlock(&ctl->tree_lock);
+
+ return ino;
+}
+
+struct inode *lookup_free_ino_inode(struct btrfs_root *root,
+ struct btrfs_path *path)
+{
+ struct inode *inode = NULL;
+
+ spin_lock(&root->cache_lock);
+ if (root->cache_inode)
+ inode = igrab(root->cache_inode);
+ spin_unlock(&root->cache_lock);
+ if (inode)
+ return inode;
+
+ inode = __lookup_free_space_inode(root, path, 0);
+ if (IS_ERR(inode))
+ return inode;
+
+ spin_lock(&root->cache_lock);
+ if (!btrfs_fs_closing(root->fs_info))
+ root->cache_inode = igrab(inode);
+ spin_unlock(&root->cache_lock);
+
+ return inode;
+}
+
+int create_free_ino_inode(struct btrfs_root *root,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_path *path)
+{
+ return __create_free_space_inode(root, trans, path,
+ BTRFS_FREE_INO_OBJECTID, 0);
+}
+
+int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
+{
+ struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
+ struct btrfs_path *path;
+ struct inode *inode;
+ int ret = 0;
+ u64 root_gen = btrfs_root_generation(&root->root_item);
+
+ if (!btrfs_test_opt(root, INODE_MAP_CACHE))
+ return 0;
+
+ /*
+ * If we're unmounting then just return, since this does a search on the
+ * normal root and not the commit root and we could deadlock.
+ */
+ if (btrfs_fs_closing(fs_info))
+ return 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return 0;
+
+ inode = lookup_free_ino_inode(root, path);
+ if (IS_ERR(inode))
+ goto out;
+
+ if (root_gen != BTRFS_I(inode)->generation)
+ goto out_put;
+
+ ret = __load_free_space_cache(root, inode, ctl, path, 0);
+
+ if (ret < 0)
+ printk(KERN_ERR "btrfs: failed to load free ino cache for "
+ "root %llu\n", root->root_key.objectid);
+out_put:
+ iput(inode);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_write_out_ino_cache(struct btrfs_root *root,
+ struct btrfs_trans_handle *trans,
+ struct btrfs_path *path)
+{
+ struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
+ struct inode *inode;
+ int ret;
+
+ if (!btrfs_test_opt(root, INODE_MAP_CACHE))
+ return 0;
+
+ inode = lookup_free_ino_inode(root, path);
+ if (IS_ERR(inode))
+ return 0;
+
+ ret = __btrfs_write_out_cache(root, inode, ctl, NULL, trans, path, 0);
+ if (ret) {
+ btrfs_delalloc_release_metadata(inode, inode->i_size);
+#ifdef DEBUG
+ printk(KERN_ERR "btrfs: failed to write free ino cache "
+ "for root %llu\n", root->root_key.objectid);
+#endif
+ }
+
+ iput(inode);
+ return ret;
+}