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0006-f2fs-add-node-operations.patch
1827 lines (1817 loc) · 44.6 KB
/
0006-f2fs-add-node-operations.patch
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From d82d4ed9ade4bc588b919fbc58825ba5c003c637 Mon Sep 17 00:00:00 2001
From: ??? <jaegeuk.kim@samsung.com>
Date: Tue, 23 Oct 2012 02:28:19 +0000
Subject: [PATCH 06/20] f2fs: add node operations
This adds specific functions to manage NAT pages, a cache for NAT entries, free
nids, direct/indirect node blocks for indexing data, and address space for node
pages.
- The key information of an NAT entry consists of a node id and a block address.
- An NAT page is composed of block addresses covered by a certain range of NAT
entries, which is maintained by the address space of meta_inode.
- A radix tree structure is used to cache NAT entries. The index for the tree
is a node id.
- When there is no free nid, F2FS should scan NAT entries to find new one. In
order to avoid scanning frequently, F2FS manages a list containing a number of
free nids in memory. Only when free nids in the list are exhausted, scanning
process, build_free_nids(), is triggered.
- F2FS has direct and indirect node blocks for indexing data. This patch adds
fuctions related to the node block management such as getting, allocating, and
truncating node blocks to index data.
- In order to cache node blocks in memory, F2FS has a node_inode with an address
space for node pages. This patch also adds the address space operations for
node_inode.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
---
fs/f2fs/node.c | 1782 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 1782 insertions(+), 0 deletions(-)
create mode 100644 fs/f2fs/node.c
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
new file mode 100644
index 0000000..df69058
--- /dev/null
+++ b/fs/f2fs/node.c
@@ -0,0 +1,1782 @@
+/**
+ * fs/f2fs/node.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ * http://www.samsung.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/mpage.h>
+#include <linux/backing-dev.h>
+#include <linux/blkdev.h>
+#include <linux/pagevec.h>
+#include <linux/swap.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+
+static struct kmem_cache *nat_entry_slab;
+static struct kmem_cache *free_nid_slab;
+
+static void clear_node_page_dirty(struct page *page)
+{
+ struct address_space *mapping = page->mapping;
+ struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
+ unsigned int long flags;
+
+ if (PageDirty(page)) {
+ spin_lock_irqsave(&mapping->tree_lock, flags);
+ radix_tree_tag_clear(&mapping->page_tree,
+ page_index(page),
+ PAGECACHE_TAG_DIRTY);
+ spin_unlock_irqrestore(&mapping->tree_lock, flags);
+
+ clear_page_dirty_for_io(page);
+ dec_page_count(sbi, F2FS_DIRTY_NODES);
+ }
+ ClearPageUptodate(page);
+}
+
+static struct page *get_current_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
+{
+ pgoff_t index = current_nat_addr(sbi, nid);
+ return get_meta_page(sbi, index);
+}
+
+static struct page *get_next_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
+{
+ struct page *src_page;
+ struct page *dst_page;
+ pgoff_t src_off;
+ pgoff_t dst_off;
+ void *src_addr;
+ void *dst_addr;
+ struct f2fs_nm_info *nm_i = NM_I(sbi);
+
+ src_off = current_nat_addr(sbi, nid);
+ dst_off = next_nat_addr(sbi, src_off);
+
+ /* get current nat block page with lock */
+ src_page = get_meta_page(sbi, src_off);
+
+ /* Dirty src_page means that it is already the new target NAT page. */
+ if (PageDirty(src_page))
+ return src_page;
+
+ dst_page = grab_meta_page(sbi, dst_off);
+
+ src_addr = page_address(src_page);
+ dst_addr = page_address(dst_page);
+ memcpy(dst_addr, src_addr, PAGE_CACHE_SIZE);
+ set_page_dirty(dst_page);
+ f2fs_put_page(src_page, 1);
+
+ set_to_next_nat(nm_i, nid);
+
+ return dst_page;
+}
+
+/**
+ * Readahead NAT pages
+ */
+static void ra_nat_pages(struct f2fs_sb_info *sbi, int nid)
+{
+ struct address_space *mapping = sbi->meta_inode->i_mapping;
+ struct f2fs_nm_info *nm_i = NM_I(sbi);
+ struct page *page;
+ pgoff_t index;
+ int i;
+
+ for (i = 0; i < FREE_NID_PAGES; i++, nid += NAT_ENTRY_PER_BLOCK) {
+ if (nid >= nm_i->max_nid)
+ nid = 0;
+ index = current_nat_addr(sbi, nid);
+
+ page = grab_cache_page(mapping, index);
+ if (!page)
+ continue;
+ if (f2fs_readpage(sbi, page, index, READ)) {
+ f2fs_put_page(page, 1);
+ continue;
+ }
+ page_cache_release(page);
+ }
+}
+
+static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n)
+{
+ return radix_tree_lookup(&nm_i->nat_root, n);
+}
+
+static unsigned int __gang_lookup_nat_cache(struct f2fs_nm_info *nm_i,
+ nid_t start, unsigned int nr, struct nat_entry **ep)
+{
+ return radix_tree_gang_lookup(&nm_i->nat_root, (void **)ep, start, nr);
+}
+
+static void __del_from_nat_cache(struct f2fs_nm_info *nm_i, struct nat_entry *e)
+{
+ list_del(&e->list);
+ radix_tree_delete(&nm_i->nat_root, nat_get_nid(e));
+ nm_i->nat_cnt--;
+ kmem_cache_free(nat_entry_slab, e);
+}
+
+int is_checkpointed_node(struct f2fs_sb_info *sbi, nid_t nid)
+{
+ struct f2fs_nm_info *nm_i = NM_I(sbi);
+ struct nat_entry *e;
+ int is_cp = 1;
+
+ read_lock(&nm_i->nat_tree_lock);
+ e = __lookup_nat_cache(nm_i, nid);
+ if (e && !e->checkpointed)
+ is_cp = 0;
+ read_unlock(&nm_i->nat_tree_lock);
+ return is_cp;
+}
+
+static struct nat_entry *grab_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid)
+{
+ struct nat_entry *new;
+
+ new = kmem_cache_alloc(nat_entry_slab, GFP_ATOMIC);
+ if (!new)
+ return NULL;
+ if (radix_tree_insert(&nm_i->nat_root, nid, new)) {
+ kmem_cache_free(nat_entry_slab, new);
+ return NULL;
+ }
+ memset(new, 0, sizeof(struct nat_entry));
+ nat_set_nid(new, nid);
+ list_add_tail(&new->list, &nm_i->nat_entries);
+ nm_i->nat_cnt++;
+ return new;
+}
+
+static void cache_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid,
+ struct f2fs_nat_entry *ne)
+{
+ struct nat_entry *e;
+retry:
+ write_lock(&nm_i->nat_tree_lock);
+ e = __lookup_nat_cache(nm_i, nid);
+ if (!e) {
+ e = grab_nat_entry(nm_i, nid);
+ if (!e) {
+ write_unlock(&nm_i->nat_tree_lock);
+ goto retry;
+ }
+ nat_set_blkaddr(e, le32_to_cpu(ne->block_addr));
+ nat_set_ino(e, le32_to_cpu(ne->ino));
+ nat_set_version(e, ne->version);
+ e->checkpointed = true;
+ }
+ write_unlock(&nm_i->nat_tree_lock);
+}
+
+static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
+ block_t new_blkaddr)
+{
+ struct f2fs_nm_info *nm_i = NM_I(sbi);
+ struct nat_entry *e;
+retry:
+ write_lock(&nm_i->nat_tree_lock);
+ e = __lookup_nat_cache(nm_i, ni->nid);
+ if (!e) {
+ e = grab_nat_entry(nm_i, ni->nid);
+ if (!e) {
+ write_unlock(&nm_i->nat_tree_lock);
+ goto retry;
+ }
+ e->ni = *ni;
+ e->checkpointed = true;
+ BUG_ON(ni->blk_addr == NEW_ADDR);
+ } else if (new_blkaddr == NEW_ADDR) {
+ /*
+ * when nid is reallocated,
+ * previous nat entry can be remained in nat cache.
+ * So, reinitialize it with new information.
+ */
+ e->ni = *ni;
+ BUG_ON(ni->blk_addr != NULL_ADDR);
+ }
+
+ if (new_blkaddr == NEW_ADDR)
+ e->checkpointed = false;
+
+ /* sanity check */
+ BUG_ON(nat_get_blkaddr(e) != ni->blk_addr);
+ BUG_ON(nat_get_blkaddr(e) == NULL_ADDR &&
+ new_blkaddr == NULL_ADDR);
+ BUG_ON(nat_get_blkaddr(e) == NEW_ADDR &&
+ new_blkaddr == NEW_ADDR);
+ BUG_ON(nat_get_blkaddr(e) != NEW_ADDR &&
+ nat_get_blkaddr(e) != NULL_ADDR &&
+ new_blkaddr == NEW_ADDR);
+
+ /* increament version no as node is removed */
+ if (nat_get_blkaddr(e) != NEW_ADDR && new_blkaddr == NULL_ADDR) {
+ unsigned char version = nat_get_version(e);
+ nat_set_version(e, inc_node_version(version));
+ }
+
+ /* change address */
+ nat_set_blkaddr(e, new_blkaddr);
+ __set_nat_cache_dirty(nm_i, e);
+ write_unlock(&nm_i->nat_tree_lock);
+}
+
+static int try_to_free_nats(struct f2fs_sb_info *sbi, int nr_shrink)
+{
+ struct f2fs_nm_info *nm_i = NM_I(sbi);
+
+ if (nm_i->nat_cnt < 2 * NM_WOUT_THRESHOLD)
+ return 0;
+
+ write_lock(&nm_i->nat_tree_lock);
+ while (nr_shrink && !list_empty(&nm_i->nat_entries)) {
+ struct nat_entry *ne;
+ ne = list_first_entry(&nm_i->nat_entries,
+ struct nat_entry, list);
+ __del_from_nat_cache(nm_i, ne);
+ nr_shrink--;
+ }
+ write_unlock(&nm_i->nat_tree_lock);
+ return nr_shrink;
+}
+
+/**
+ * This function returns always success
+ */
+void get_node_info(struct f2fs_sb_info *sbi, nid_t nid, struct node_info *ni)
+{
+ struct f2fs_nm_info *nm_i = NM_I(sbi);
+ struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
+ struct f2fs_summary_block *sum = curseg->sum_blk;
+ nid_t start_nid = START_NID(nid);
+ struct f2fs_nat_block *nat_blk;
+ struct page *page = NULL;
+ struct f2fs_nat_entry ne;
+ struct nat_entry *e;
+ int i;
+
+ ni->nid = nid;
+
+ /* Check nat cache */
+ read_lock(&nm_i->nat_tree_lock);
+ e = __lookup_nat_cache(nm_i, nid);
+ if (e) {
+ ni->ino = nat_get_ino(e);
+ ni->blk_addr = nat_get_blkaddr(e);
+ ni->version = nat_get_version(e);
+ }
+ read_unlock(&nm_i->nat_tree_lock);
+ if (e)
+ return;
+
+ /* Check current segment summary */
+ mutex_lock(&curseg->curseg_mutex);
+ i = lookup_journal_in_cursum(sum, NAT_JOURNAL, nid, 0);
+ if (i >= 0) {
+ ne = nat_in_journal(sum, i);
+ node_info_from_raw_nat(ni, &ne);
+ }
+ mutex_unlock(&curseg->curseg_mutex);
+ if (i >= 0)
+ goto cache;
+
+ /* Fill node_info from nat page */
+ page = get_current_nat_page(sbi, start_nid);
+ nat_blk = (struct f2fs_nat_block *)page_address(page);
+ ne = nat_blk->entries[nid - start_nid];
+ node_info_from_raw_nat(ni, &ne);
+ f2fs_put_page(page, 1);
+cache:
+ /* cache nat entry */
+ cache_nat_entry(NM_I(sbi), nid, &ne);
+}
+
+/**
+ * The maximum depth is four.
+ * Offset[0] will have raw inode offset.
+ */
+static int get_node_path(long block, int offset[4], unsigned int noffset[4])
+{
+ const long direct_index = ADDRS_PER_INODE;
+ const long direct_blks = ADDRS_PER_BLOCK;
+ const long dptrs_per_blk = NIDS_PER_BLOCK;
+ const long indirect_blks = ADDRS_PER_BLOCK * NIDS_PER_BLOCK;
+ const long dindirect_blks = indirect_blks * NIDS_PER_BLOCK;
+ int n = 0;
+ int level = 0;
+
+ noffset[0] = 0;
+
+ if (block < direct_index) {
+ offset[n++] = block;
+ level = 0;
+ goto got;
+ }
+ block -= direct_index;
+ if (block < direct_blks) {
+ offset[n++] = NODE_DIR1_BLOCK;
+ noffset[n] = 1;
+ offset[n++] = block;
+ level = 1;
+ goto got;
+ }
+ block -= direct_blks;
+ if (block < direct_blks) {
+ offset[n++] = NODE_DIR2_BLOCK;
+ noffset[n] = 2;
+ offset[n++] = block;
+ level = 1;
+ goto got;
+ }
+ block -= direct_blks;
+ if (block < indirect_blks) {
+ offset[n++] = NODE_IND1_BLOCK;
+ noffset[n] = 3;
+ offset[n++] = block / direct_blks;
+ noffset[n] = 4 + offset[n - 1];
+ offset[n++] = block % direct_blks;
+ level = 2;
+ goto got;
+ }
+ block -= indirect_blks;
+ if (block < indirect_blks) {
+ offset[n++] = NODE_IND2_BLOCK;
+ noffset[n] = 4 + dptrs_per_blk;
+ offset[n++] = block / direct_blks;
+ noffset[n] = 5 + dptrs_per_blk + offset[n - 1];
+ offset[n++] = block % direct_blks;
+ level = 2;
+ goto got;
+ }
+ block -= indirect_blks;
+ if (block < dindirect_blks) {
+ offset[n++] = NODE_DIND_BLOCK;
+ noffset[n] = 5 + (dptrs_per_blk * 2);
+ offset[n++] = block / indirect_blks;
+ noffset[n] = 6 + (dptrs_per_blk * 2) +
+ offset[n - 1] * (dptrs_per_blk + 1);
+ offset[n++] = (block / direct_blks) % dptrs_per_blk;
+ noffset[n] = 7 + (dptrs_per_blk * 2) +
+ offset[n - 2] * (dptrs_per_blk + 1) +
+ offset[n - 1];
+ offset[n++] = block % direct_blks;
+ level = 3;
+ goto got;
+ } else {
+ BUG();
+ }
+got:
+ return level;
+}
+
+/*
+ * Caller should call f2fs_put_dnode(dn).
+ */
+int get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int ro)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
+ struct page *npage[4];
+ struct page *parent;
+ int offset[4];
+ unsigned int noffset[4];
+ nid_t nids[4];
+ int level, i;
+ int err = 0;
+
+ level = get_node_path(index, offset, noffset);
+
+ nids[0] = dn->inode->i_ino;
+ npage[0] = get_node_page(sbi, nids[0]);
+ if (IS_ERR(npage[0]))
+ return PTR_ERR(npage[0]);
+
+ parent = npage[0];
+ nids[1] = get_nid(parent, offset[0], true);
+ dn->inode_page = npage[0];
+ dn->inode_page_locked = true;
+
+ /* get indirect or direct nodes */
+ for (i = 1; i <= level; i++) {
+ bool done = false;
+
+ if (!nids[i] && !ro) {
+ mutex_lock_op(sbi, NODE_NEW);
+
+ /* alloc new node */
+ if (!alloc_nid(sbi, &(nids[i]))) {
+ mutex_unlock_op(sbi, NODE_NEW);
+ err = -ENOSPC;
+ goto release_pages;
+ }
+
+ dn->nid = nids[i];
+ npage[i] = new_node_page(dn, noffset[i]);
+ if (IS_ERR(npage[i])) {
+ alloc_nid_failed(sbi, nids[i]);
+ mutex_unlock_op(sbi, NODE_NEW);
+ err = PTR_ERR(npage[i]);
+ goto release_pages;
+ }
+
+ set_nid(parent, offset[i - 1], nids[i], i == 1);
+ alloc_nid_done(sbi, nids[i]);
+ mutex_unlock_op(sbi, NODE_NEW);
+ done = true;
+ } else if (ro && i == level && level > 1) {
+ npage[i] = get_node_page_ra(parent, offset[i - 1]);
+ if (IS_ERR(npage[i])) {
+ err = PTR_ERR(npage[i]);
+ goto release_pages;
+ }
+ done = true;
+ }
+ if (i == 1) {
+ dn->inode_page_locked = false;
+ unlock_page(parent);
+ } else {
+ f2fs_put_page(parent, 1);
+ }
+
+ if (!done) {
+ npage[i] = get_node_page(sbi, nids[i]);
+ if (IS_ERR(npage[i])) {
+ err = PTR_ERR(npage[i]);
+ f2fs_put_page(npage[0], 0);
+ goto release_out;
+ }
+ }
+ if (i < level) {
+ parent = npage[i];
+ nids[i + 1] = get_nid(parent, offset[i], false);
+ }
+ }
+ dn->nid = nids[level];
+ dn->ofs_in_node = offset[level];
+ dn->node_page = npage[level];
+ dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
+ return 0;
+
+release_pages:
+ f2fs_put_page(parent, 1);
+ if (i > 1)
+ f2fs_put_page(npage[0], 0);
+release_out:
+ dn->inode_page = NULL;
+ dn->node_page = NULL;
+ return err;
+}
+
+static void truncate_node(struct dnode_of_data *dn)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
+ struct node_info ni;
+
+ get_node_info(sbi, dn->nid, &ni);
+ BUG_ON(ni.blk_addr == NULL_ADDR);
+
+ if (ni.blk_addr != NULL_ADDR)
+ invalidate_blocks(sbi, ni.blk_addr);
+
+ /* Deallocate node address */
+ dec_valid_node_count(sbi, dn->inode, 1);
+ set_node_addr(sbi, &ni, NULL_ADDR);
+
+ if (dn->nid == dn->inode->i_ino) {
+ remove_orphan_inode(sbi, dn->nid);
+ dec_valid_inode_count(sbi);
+ } else {
+ sync_inode_page(dn);
+ }
+
+ clear_node_page_dirty(dn->node_page);
+ F2FS_SET_SB_DIRT(sbi);
+
+ f2fs_put_page(dn->node_page, 1);
+ dn->node_page = NULL;
+}
+
+static int truncate_dnode(struct dnode_of_data *dn)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
+ struct page *page;
+
+ if (dn->nid == 0)
+ return 1;
+
+ /* get direct node */
+ page = get_node_page(sbi, dn->nid);
+ if (IS_ERR(page) && PTR_ERR(page) == -ENOENT)
+ return 1;
+ else if (IS_ERR(page))
+ return PTR_ERR(page);
+
+ /* Make dnode_of_data for parameter */
+ dn->node_page = page;
+ dn->ofs_in_node = 0;
+ truncate_data_blocks(dn);
+ truncate_node(dn);
+ return 1;
+}
+
+static int truncate_nodes(struct dnode_of_data *dn, unsigned int nofs,
+ int ofs, int depth)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
+ struct dnode_of_data rdn = *dn;
+ struct page *page;
+ struct f2fs_node *rn;
+ nid_t child_nid;
+ unsigned int child_nofs;
+ int freed = 0;
+ int i, ret;
+
+ if (dn->nid == 0)
+ return NIDS_PER_BLOCK + 1;
+
+ page = get_node_page(sbi, dn->nid);
+ if (IS_ERR(page))
+ return PTR_ERR(page);
+
+ rn = (struct f2fs_node *)page_address(page);
+ if (depth < 3) {
+ for (i = ofs; i < NIDS_PER_BLOCK; i++, freed++) {
+ child_nid = le32_to_cpu(rn->in.nid[i]);
+ if (child_nid == 0)
+ continue;
+ rdn.nid = child_nid;
+ ret = truncate_dnode(&rdn);
+ if (ret < 0)
+ goto out_err;
+ set_nid(page, i, 0, false);
+ }
+ } else {
+ child_nofs = nofs + ofs * (NIDS_PER_BLOCK + 1) + 1;
+ for (i = ofs; i < NIDS_PER_BLOCK; i++) {
+ child_nid = le32_to_cpu(rn->in.nid[i]);
+ if (child_nid == 0) {
+ child_nofs += NIDS_PER_BLOCK + 1;
+ continue;
+ }
+ rdn.nid = child_nid;
+ ret = truncate_nodes(&rdn, child_nofs, 0, depth - 1);
+ if (ret == (NIDS_PER_BLOCK + 1)) {
+ set_nid(page, i, 0, false);
+ child_nofs += ret;
+ } else if (ret < 0 && ret != -ENOENT) {
+ goto out_err;
+ }
+ }
+ freed = child_nofs;
+ }
+
+ if (!ofs) {
+ /* remove current indirect node */
+ dn->node_page = page;
+ truncate_node(dn);
+ freed++;
+ } else {
+ f2fs_put_page(page, 1);
+ }
+ return freed;
+
+out_err:
+ f2fs_put_page(page, 1);
+ return ret;
+}
+
+static int truncate_partial_nodes(struct dnode_of_data *dn,
+ struct f2fs_inode *ri, int *offset, int depth)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
+ struct page *pages[2];
+ nid_t nid[3];
+ nid_t child_nid;
+ int err = 0;
+ int i;
+ int idx = depth - 2;
+
+ nid[0] = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]);
+ if (!nid[0])
+ return 0;
+
+ /* get indirect nodes in the path */
+ for (i = 0; i < depth - 1; i++) {
+ /* refernece count'll be increased */
+ pages[i] = get_node_page(sbi, nid[i]);
+ if (IS_ERR(pages[i])) {
+ depth = i + 1;
+ err = PTR_ERR(pages[i]);
+ goto fail;
+ }
+ nid[i + 1] = get_nid(pages[i], offset[i + 1], false);
+ }
+
+ /* free direct nodes linked to a partial indirect node */
+ for (i = offset[depth - 1]; i < NIDS_PER_BLOCK; i++) {
+ child_nid = get_nid(pages[idx], i, false);
+ if (!child_nid)
+ continue;
+ dn->nid = child_nid;
+ err = truncate_dnode(dn);
+ if (err < 0)
+ goto fail;
+ set_nid(pages[idx], i, 0, false);
+ }
+
+ if (offset[depth - 1] == 0) {
+ dn->node_page = pages[idx];
+ dn->nid = nid[idx];
+ truncate_node(dn);
+ } else {
+ f2fs_put_page(pages[idx], 1);
+ }
+ offset[idx]++;
+ offset[depth - 1] = 0;
+fail:
+ for (i = depth - 3; i >= 0; i--)
+ f2fs_put_page(pages[i], 1);
+ return err;
+}
+
+/**
+ * All the block addresses of data and nodes should be nullified.
+ */
+int truncate_inode_blocks(struct inode *inode, pgoff_t from)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+ int err = 0, cont = 1;
+ int level, offset[4], noffset[4];
+ unsigned int nofs;
+ struct f2fs_node *rn;
+ struct dnode_of_data dn;
+ struct page *page;
+
+ level = get_node_path(from, offset, noffset);
+
+ page = get_node_page(sbi, inode->i_ino);
+ if (IS_ERR(page))
+ return PTR_ERR(page);
+
+ set_new_dnode(&dn, inode, page, NULL, 0);
+ unlock_page(page);
+
+ rn = page_address(page);
+ switch (level) {
+ case 0:
+ case 1:
+ nofs = noffset[1];
+ break;
+ case 2:
+ nofs = noffset[1];
+ if (!offset[level - 1])
+ goto skip_partial;
+ err = truncate_partial_nodes(&dn, &rn->i, offset, level);
+ if (err < 0 && err != -ENOENT)
+ goto fail;
+ nofs += 1 + NIDS_PER_BLOCK;
+ break;
+ case 3:
+ nofs = 5 + 2 * NIDS_PER_BLOCK;
+ if (!offset[level - 1])
+ goto skip_partial;
+ err = truncate_partial_nodes(&dn, &rn->i, offset, level);
+ if (err < 0 && err != -ENOENT)
+ goto fail;
+ break;
+ default:
+ BUG();
+ }
+
+skip_partial:
+ while (cont) {
+ dn.nid = le32_to_cpu(rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK]);
+ switch (offset[0]) {
+ case NODE_DIR1_BLOCK:
+ case NODE_DIR2_BLOCK:
+ err = truncate_dnode(&dn);
+ break;
+
+ case NODE_IND1_BLOCK:
+ case NODE_IND2_BLOCK:
+ err = truncate_nodes(&dn, nofs, offset[1], 2);
+ break;
+
+ case NODE_DIND_BLOCK:
+ err = truncate_nodes(&dn, nofs, offset[1], 3);
+ cont = 0;
+ break;
+
+ default:
+ BUG();
+ }
+ if (err < 0 && err != -ENOENT)
+ goto fail;
+ if (offset[1] == 0 &&
+ rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK]) {
+ lock_page(page);
+ wait_on_page_writeback(page);
+ rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK] = 0;
+ set_page_dirty(page);
+ unlock_page(page);
+ }
+ offset[1] = 0;
+ offset[0]++;
+ nofs += err;
+ }
+fail:
+ f2fs_put_page(page, 0);
+ return err > 0 ? 0 : err;
+}
+
+int remove_inode_page(struct inode *inode)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+ struct page *page;
+ nid_t ino = inode->i_ino;
+ struct dnode_of_data dn;
+
+ mutex_lock_op(sbi, NODE_TRUNC);
+ page = get_node_page(sbi, ino);
+ if (IS_ERR(page)) {
+ mutex_unlock_op(sbi, NODE_TRUNC);
+ return PTR_ERR(page);
+ }
+
+ if (F2FS_I(inode)->i_xattr_nid) {
+ nid_t nid = F2FS_I(inode)->i_xattr_nid;
+ struct page *npage = get_node_page(sbi, nid);
+
+ if (IS_ERR(npage)) {
+ mutex_unlock_op(sbi, NODE_TRUNC);
+ return PTR_ERR(npage);
+ }
+
+ F2FS_I(inode)->i_xattr_nid = 0;
+ set_new_dnode(&dn, inode, page, npage, nid);
+ dn.inode_page_locked = 1;
+ truncate_node(&dn);
+ }
+ if (inode->i_blocks == 1) {
+ /* inernally call f2fs_put_page() */
+ set_new_dnode(&dn, inode, page, page, ino);
+ truncate_node(&dn);
+ } else if (inode->i_blocks == 0) {
+ struct node_info ni;
+ get_node_info(sbi, inode->i_ino, &ni);
+
+ /* called after f2fs_new_inode() is failed */
+ BUG_ON(ni.blk_addr != NULL_ADDR);
+ f2fs_put_page(page, 1);
+ } else {
+ BUG();
+ }
+ mutex_unlock_op(sbi, NODE_TRUNC);
+ return 0;
+}
+
+int new_inode_page(struct inode *inode, struct dentry *dentry)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+ struct page *page;
+ struct dnode_of_data dn;
+
+ /* allocate inode page for new inode */
+ set_new_dnode(&dn, inode, NULL, NULL, inode->i_ino);
+ mutex_lock_op(sbi, NODE_NEW);
+ page = new_node_page(&dn, 0);
+ init_dent_inode(dentry, page);
+ mutex_unlock_op(sbi, NODE_NEW);
+ if (IS_ERR(page))
+ return PTR_ERR(page);
+ f2fs_put_page(page, 1);
+ return 0;
+}
+
+struct page *new_node_page(struct dnode_of_data *dn, unsigned int ofs)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
+ struct address_space *mapping = sbi->node_inode->i_mapping;
+ struct node_info old_ni, new_ni;
+ struct page *page;
+ int err;
+
+ if (is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC))
+ return ERR_PTR(-EPERM);
+
+ page = grab_cache_page(mapping, dn->nid);
+ if (!page)
+ return ERR_PTR(-ENOMEM);
+
+ get_node_info(sbi, dn->nid, &old_ni);
+
+ SetPageUptodate(page);
+ fill_node_footer(page, dn->nid, dn->inode->i_ino, ofs, true);
+
+ /* Reinitialize old_ni with new node page */
+ BUG_ON(old_ni.blk_addr != NULL_ADDR);
+ new_ni = old_ni;
+ new_ni.ino = dn->inode->i_ino;
+
+ if (!inc_valid_node_count(sbi, dn->inode, 1)) {
+ err = -ENOSPC;
+ goto fail;
+ }
+ set_node_addr(sbi, &new_ni, NEW_ADDR);
+
+ dn->node_page = page;
+ sync_inode_page(dn);
+ set_page_dirty(page);
+ set_cold_node(dn->inode, page);
+ if (ofs == 0)
+ inc_valid_inode_count(sbi);
+
+ return page;
+
+fail:
+ f2fs_put_page(page, 1);
+ return ERR_PTR(err);
+}
+
+static int read_node_page(struct page *page, int type)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
+ struct node_info ni;
+
+ get_node_info(sbi, page->index, &ni);
+
+ if (ni.blk_addr == NULL_ADDR)
+ return -ENOENT;
+ return f2fs_readpage(sbi, page, ni.blk_addr, type);
+}
+
+/**
+ * Readahead a node page
+ */
+void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
+{
+ struct address_space *mapping = sbi->node_inode->i_mapping;
+ struct page *apage;
+
+ apage = find_get_page(mapping, nid);
+ if (apage && PageUptodate(apage))
+ goto release_out;
+ f2fs_put_page(apage, 0);
+
+ apage = grab_cache_page(mapping, nid);
+ if (!apage)
+ return;
+
+ if (read_node_page(apage, READA))
+ goto unlock_out;
+
+ page_cache_release(apage);
+ return;
+
+unlock_out:
+ unlock_page(apage);
+release_out:
+ page_cache_release(apage);
+}
+
+struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
+{
+ int err;
+ struct page *page;
+ struct address_space *mapping = sbi->node_inode->i_mapping;
+
+ page = grab_cache_page(mapping, nid);
+ if (!page)
+ return ERR_PTR(-ENOMEM);
+
+ err = read_node_page(page, READ_SYNC);
+ if (err) {
+ f2fs_put_page(page, 1);
+ return ERR_PTR(err);
+ }
+
+ BUG_ON(nid != nid_of_node(page));
+ mark_page_accessed(page);
+ return page;
+}
+
+/**
+ * Return a locked page for the desired node page.
+ * And, readahead MAX_RA_NODE number of node pages.
+ */
+struct page *get_node_page_ra(struct page *parent, int start)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(parent->mapping->host->i_sb);
+ struct address_space *mapping = sbi->node_inode->i_mapping;
+ int i, end;
+ int err = 0;
+ nid_t nid;
+ struct page *page;
+
+ /* First, try getting the desired direct node. */
+ nid = get_nid(parent, start, false);
+ if (!nid)
+ return ERR_PTR(-ENOENT);
+
+ page = find_get_page(mapping, nid);
+ if (page && PageUptodate(page))
+ goto page_hit;
+ f2fs_put_page(page, 0);
+
+repeat:
+ page = grab_cache_page(mapping, nid);
+ if (!page)
+ return ERR_PTR(-ENOMEM);
+
+ err = read_node_page(page, READA);
+ if (err) {
+ f2fs_put_page(page, 1);
+ return ERR_PTR(err);
+ }
+
+ /* Then, try readahead for siblings of the desired node */
+ end = start + MAX_RA_NODE;
+ end = min(end, NIDS_PER_BLOCK);
+ for (i = start + 1; i < end; i++) {
+ nid = get_nid(parent, i, false);
+ if (!nid)
+ continue;
+ ra_node_page(sbi, nid);
+ }
+
+page_hit:
+ lock_page(page);