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-rw-r--r--fs/logfs/segment.c961
1 files changed, 0 insertions, 961 deletions
diff --git a/fs/logfs/segment.c b/fs/logfs/segment.c
deleted file mode 100644
index 1efd6055f4b0..000000000000
--- a/fs/logfs/segment.c
+++ /dev/null
@@ -1,961 +0,0 @@
-/*
- * fs/logfs/segment.c - Handling the Object Store
- *
- * As should be obvious for Linux kernel code, license is GPLv2
- *
- * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org>
- *
- * Object store or ostore makes up the complete device with exception of
- * the superblock and journal areas. Apart from its own metadata it stores
- * three kinds of objects: inodes, dentries and blocks, both data and indirect.
- */
-#include "logfs.h"
-#include <linux/slab.h>
-
-static int logfs_mark_segment_bad(struct super_block *sb, u32 segno)
-{
- struct logfs_super *super = logfs_super(sb);
- struct btree_head32 *head = &super->s_reserved_segments;
- int err;
-
- err = btree_insert32(head, segno, (void *)1, GFP_NOFS);
- if (err)
- return err;
- logfs_super(sb)->s_bad_segments++;
- /* FIXME: write to journal */
- return 0;
-}
-
-int logfs_erase_segment(struct super_block *sb, u32 segno, int ensure_erase)
-{
- struct logfs_super *super = logfs_super(sb);
-
- super->s_gec++;
-
- return super->s_devops->erase(sb, (u64)segno << super->s_segshift,
- super->s_segsize, ensure_erase);
-}
-
-static s64 logfs_get_free_bytes(struct logfs_area *area, size_t bytes)
-{
- s32 ofs;
-
- logfs_open_area(area, bytes);
-
- ofs = area->a_used_bytes;
- area->a_used_bytes += bytes;
- BUG_ON(area->a_used_bytes >= logfs_super(area->a_sb)->s_segsize);
-
- return dev_ofs(area->a_sb, area->a_segno, ofs);
-}
-
-static struct page *get_mapping_page(struct super_block *sb, pgoff_t index,
- int use_filler)
-{
- struct logfs_super *super = logfs_super(sb);
- struct address_space *mapping = super->s_mapping_inode->i_mapping;
- filler_t *filler = super->s_devops->readpage;
- struct page *page;
-
- BUG_ON(mapping_gfp_constraint(mapping, __GFP_FS));
- if (use_filler)
- page = read_cache_page(mapping, index, filler, sb);
- else {
- page = find_or_create_page(mapping, index, GFP_NOFS);
- if (page)
- unlock_page(page);
- }
- return page;
-}
-
-int __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len,
- int use_filler)
-{
- pgoff_t index = ofs >> PAGE_SHIFT;
- struct page *page;
- long offset = ofs & (PAGE_SIZE-1);
- long copylen;
-
- /* Only logfs_wbuf_recover may use len==0 */
- BUG_ON(!len && !use_filler);
- do {
- copylen = min((ulong)len, PAGE_SIZE - offset);
-
- page = get_mapping_page(area->a_sb, index, use_filler);
- if (IS_ERR(page))
- return PTR_ERR(page);
- BUG_ON(!page); /* FIXME: reserve a pool */
- SetPageUptodate(page);
- memcpy(page_address(page) + offset, buf, copylen);
-
- if (!PagePrivate(page)) {
- SetPagePrivate(page);
- get_page(page);
- }
- put_page(page);
-
- buf += copylen;
- len -= copylen;
- offset = 0;
- index++;
- } while (len);
- return 0;
-}
-
-static void pad_partial_page(struct logfs_area *area)
-{
- struct super_block *sb = area->a_sb;
- struct page *page;
- u64 ofs = dev_ofs(sb, area->a_segno, area->a_used_bytes);
- pgoff_t index = ofs >> PAGE_SHIFT;
- long offset = ofs & (PAGE_SIZE-1);
- u32 len = PAGE_SIZE - offset;
-
- if (len % PAGE_SIZE) {
- page = get_mapping_page(sb, index, 0);
- BUG_ON(!page); /* FIXME: reserve a pool */
- memset(page_address(page) + offset, 0xff, len);
- if (!PagePrivate(page)) {
- SetPagePrivate(page);
- get_page(page);
- }
- put_page(page);
- }
-}
-
-static void pad_full_pages(struct logfs_area *area)
-{
- struct super_block *sb = area->a_sb;
- struct logfs_super *super = logfs_super(sb);
- u64 ofs = dev_ofs(sb, area->a_segno, area->a_used_bytes);
- u32 len = super->s_segsize - area->a_used_bytes;
- pgoff_t index = PAGE_ALIGN(ofs) >> PAGE_SHIFT;
- pgoff_t no_indizes = len >> PAGE_SHIFT;
- struct page *page;
-
- while (no_indizes) {
- page = get_mapping_page(sb, index, 0);
- BUG_ON(!page); /* FIXME: reserve a pool */
- SetPageUptodate(page);
- memset(page_address(page), 0xff, PAGE_SIZE);
- if (!PagePrivate(page)) {
- SetPagePrivate(page);
- get_page(page);
- }
- put_page(page);
- index++;
- no_indizes--;
- }
-}
-
-/*
- * bdev_writeseg will write full pages. Memset the tail to prevent data leaks.
- * Also make sure we allocate (and memset) all pages for final writeout.
- */
-static void pad_wbuf(struct logfs_area *area, int final)
-{
- pad_partial_page(area);
- if (final)
- pad_full_pages(area);
-}
-
-/*
- * We have to be careful with the alias tree. Since lookup is done by bix,
- * it needs to be normalized, so 14, 15, 16, etc. all match when dealing with
- * indirect blocks. So always use it through accessor functions.
- */
-static void *alias_tree_lookup(struct super_block *sb, u64 ino, u64 bix,
- level_t level)
-{
- struct btree_head128 *head = &logfs_super(sb)->s_object_alias_tree;
- pgoff_t index = logfs_pack_index(bix, level);
-
- return btree_lookup128(head, ino, index);
-}
-
-static int alias_tree_insert(struct super_block *sb, u64 ino, u64 bix,
- level_t level, void *val)
-{
- struct btree_head128 *head = &logfs_super(sb)->s_object_alias_tree;
- pgoff_t index = logfs_pack_index(bix, level);
-
- return btree_insert128(head, ino, index, val, GFP_NOFS);
-}
-
-static int btree_write_alias(struct super_block *sb, struct logfs_block *block,
- write_alias_t *write_one_alias)
-{
- struct object_alias_item *item;
- int err;
-
- list_for_each_entry(item, &block->item_list, list) {
- err = write_alias_journal(sb, block->ino, block->bix,
- block->level, item->child_no, item->val);
- if (err)
- return err;
- }
- return 0;
-}
-
-static const struct logfs_block_ops btree_block_ops = {
- .write_block = btree_write_block,
- .free_block = __free_block,
- .write_alias = btree_write_alias,
-};
-
-int logfs_load_object_aliases(struct super_block *sb,
- struct logfs_obj_alias *oa, int count)
-{
- struct logfs_super *super = logfs_super(sb);
- struct logfs_block *block;
- struct object_alias_item *item;
- u64 ino, bix;
- level_t level;
- int i, err;
-
- super->s_flags |= LOGFS_SB_FLAG_OBJ_ALIAS;
- count /= sizeof(*oa);
- for (i = 0; i < count; i++) {
- item = mempool_alloc(super->s_alias_pool, GFP_NOFS);
- if (!item)
- return -ENOMEM;
- memset(item, 0, sizeof(*item));
-
- super->s_no_object_aliases++;
- item->val = oa[i].val;
- item->child_no = be16_to_cpu(oa[i].child_no);
-
- ino = be64_to_cpu(oa[i].ino);
- bix = be64_to_cpu(oa[i].bix);
- level = LEVEL(oa[i].level);
-
- log_aliases("logfs_load_object_aliases(%llx, %llx, %x, %x) %llx\n",
- ino, bix, level, item->child_no,
- be64_to_cpu(item->val));
- block = alias_tree_lookup(sb, ino, bix, level);
- if (!block) {
- block = __alloc_block(sb, ino, bix, level);
- block->ops = &btree_block_ops;
- err = alias_tree_insert(sb, ino, bix, level, block);
- BUG_ON(err); /* mempool empty */
- }
- if (test_and_set_bit(item->child_no, block->alias_map)) {
- printk(KERN_ERR"LogFS: Alias collision detected\n");
- return -EIO;
- }
- list_move_tail(&block->alias_list, &super->s_object_alias);
- list_add(&item->list, &block->item_list);
- }
- return 0;
-}
-
-static void kill_alias(void *_block, unsigned long ignore0,
- u64 ignore1, u64 ignore2, size_t ignore3)
-{
- struct logfs_block *block = _block;
- struct super_block *sb = block->sb;
- struct logfs_super *super = logfs_super(sb);
- struct object_alias_item *item;
-
- while (!list_empty(&block->item_list)) {
- item = list_entry(block->item_list.next, typeof(*item), list);
- list_del(&item->list);
- mempool_free(item, super->s_alias_pool);
- }
- block->ops->free_block(sb, block);
-}
-
-static int obj_type(struct inode *inode, level_t level)
-{
- if (level == 0) {
- if (S_ISDIR(inode->i_mode))
- return OBJ_DENTRY;
- if (inode->i_ino == LOGFS_INO_MASTER)
- return OBJ_INODE;
- }
- return OBJ_BLOCK;
-}
-
-static int obj_len(struct super_block *sb, int obj_type)
-{
- switch (obj_type) {
- case OBJ_DENTRY:
- return sizeof(struct logfs_disk_dentry);
- case OBJ_INODE:
- return sizeof(struct logfs_disk_inode);
- case OBJ_BLOCK:
- return sb->s_blocksize;
- default:
- BUG();
- }
-}
-
-static int __logfs_segment_write(struct inode *inode, void *buf,
- struct logfs_shadow *shadow, int type, int len, int compr)
-{
- struct logfs_area *area;
- struct super_block *sb = inode->i_sb;
- s64 ofs;
- struct logfs_object_header h;
- int acc_len;
-
- if (shadow->gc_level == 0)
- acc_len = len;
- else
- acc_len = obj_len(sb, type);
-
- area = get_area(sb, shadow->gc_level);
- ofs = logfs_get_free_bytes(area, len + LOGFS_OBJECT_HEADERSIZE);
- LOGFS_BUG_ON(ofs <= 0, sb);
- /*
- * Order is important. logfs_get_free_bytes(), by modifying the
- * segment file, may modify the content of the very page we're about
- * to write now. Which is fine, as long as the calculated crc and
- * written data still match. So do the modifications _before_
- * calculating the crc.
- */
-
- h.len = cpu_to_be16(len);
- h.type = type;
- h.compr = compr;
- h.ino = cpu_to_be64(inode->i_ino);
- h.bix = cpu_to_be64(shadow->bix);
- h.crc = logfs_crc32(&h, sizeof(h) - 4, 4);
- h.data_crc = logfs_crc32(buf, len, 0);
-
- logfs_buf_write(area, ofs, &h, sizeof(h));
- logfs_buf_write(area, ofs + LOGFS_OBJECT_HEADERSIZE, buf, len);
-
- shadow->new_ofs = ofs;
- shadow->new_len = acc_len + LOGFS_OBJECT_HEADERSIZE;
-
- return 0;
-}
-
-static s64 logfs_segment_write_compress(struct inode *inode, void *buf,
- struct logfs_shadow *shadow, int type, int len)
-{
- struct super_block *sb = inode->i_sb;
- void *compressor_buf = logfs_super(sb)->s_compressed_je;
- ssize_t compr_len;
- int ret;
-
- mutex_lock(&logfs_super(sb)->s_journal_mutex);
- compr_len = logfs_compress(buf, compressor_buf, len, len);
-
- if (compr_len >= 0) {
- ret = __logfs_segment_write(inode, compressor_buf, shadow,
- type, compr_len, COMPR_ZLIB);
- } else {
- ret = __logfs_segment_write(inode, buf, shadow, type, len,
- COMPR_NONE);
- }
- mutex_unlock(&logfs_super(sb)->s_journal_mutex);
- return ret;
-}
-
-/**
- * logfs_segment_write - write data block to object store
- * @inode: inode containing data
- *
- * Returns an errno or zero.
- */
-int logfs_segment_write(struct inode *inode, struct page *page,
- struct logfs_shadow *shadow)
-{
- struct super_block *sb = inode->i_sb;
- struct logfs_super *super = logfs_super(sb);
- int do_compress, type, len;
- int ret;
- void *buf;
-
- super->s_flags |= LOGFS_SB_FLAG_DIRTY;
- BUG_ON(super->s_flags & LOGFS_SB_FLAG_SHUTDOWN);
- do_compress = logfs_inode(inode)->li_flags & LOGFS_IF_COMPRESSED;
- if (shadow->gc_level != 0) {
- /* temporarily disable compression for indirect blocks */
- do_compress = 0;
- }
-
- type = obj_type(inode, shrink_level(shadow->gc_level));
- len = obj_len(sb, type);
- buf = kmap(page);
- if (do_compress)
- ret = logfs_segment_write_compress(inode, buf, shadow, type,
- len);
- else
- ret = __logfs_segment_write(inode, buf, shadow, type, len,
- COMPR_NONE);
- kunmap(page);
-
- log_segment("logfs_segment_write(%llx, %llx, %x) %llx->%llx %x->%x\n",
- shadow->ino, shadow->bix, shadow->gc_level,
- shadow->old_ofs, shadow->new_ofs,
- shadow->old_len, shadow->new_len);
- /* this BUG_ON did catch a locking bug. useful */
- BUG_ON(!(shadow->new_ofs & (super->s_segsize - 1)));
- return ret;
-}
-
-int wbuf_read(struct super_block *sb, u64 ofs, size_t len, void *buf)
-{
- pgoff_t index = ofs >> PAGE_SHIFT;
- struct page *page;
- long offset = ofs & (PAGE_SIZE-1);
- long copylen;
-
- while (len) {
- copylen = min((ulong)len, PAGE_SIZE - offset);
-
- page = get_mapping_page(sb, index, 1);
- if (IS_ERR(page))
- return PTR_ERR(page);
- memcpy(buf, page_address(page) + offset, copylen);
- put_page(page);
-
- buf += copylen;
- len -= copylen;
- offset = 0;
- index++;
- }
- return 0;
-}
-
-/*
- * The "position" of indirect blocks is ambiguous. It can be the position
- * of any data block somewhere behind this indirect block. So we need to
- * normalize the positions through logfs_block_mask() before comparing.
- */
-static int check_pos(struct super_block *sb, u64 pos1, u64 pos2, level_t level)
-{
- return (pos1 & logfs_block_mask(sb, level)) !=
- (pos2 & logfs_block_mask(sb, level));
-}
-
-#if 0
-static int read_seg_header(struct super_block *sb, u64 ofs,
- struct logfs_segment_header *sh)
-{
- __be32 crc;
- int err;
-
- err = wbuf_read(sb, ofs, sizeof(*sh), sh);
- if (err)
- return err;
- crc = logfs_crc32(sh, sizeof(*sh), 4);
- if (crc != sh->crc) {
- printk(KERN_ERR"LOGFS: header crc error at %llx: expected %x, "
- "got %x\n", ofs, be32_to_cpu(sh->crc),
- be32_to_cpu(crc));
- return -EIO;
- }
- return 0;
-}
-#endif
-
-static int read_obj_header(struct super_block *sb, u64 ofs,
- struct logfs_object_header *oh)
-{
- __be32 crc;
- int err;
-
- err = wbuf_read(sb, ofs, sizeof(*oh), oh);
- if (err)
- return err;
- crc = logfs_crc32(oh, sizeof(*oh) - 4, 4);
- if (crc != oh->crc) {
- printk(KERN_ERR"LOGFS: header crc error at %llx: expected %x, "
- "got %x\n", ofs, be32_to_cpu(oh->crc),
- be32_to_cpu(crc));
- return -EIO;
- }
- return 0;
-}
-
-static void move_btree_to_page(struct inode *inode, struct page *page,
- __be64 *data)
-{
- struct super_block *sb = inode->i_sb;
- struct logfs_super *super = logfs_super(sb);
- struct btree_head128 *head = &super->s_object_alias_tree;
- struct logfs_block *block;
- struct object_alias_item *item, *next;
-
- if (!(super->s_flags & LOGFS_SB_FLAG_OBJ_ALIAS))
- return;
-
- block = btree_remove128(head, inode->i_ino, page->index);
- if (!block)
- return;
-
- log_blockmove("move_btree_to_page(%llx, %llx, %x)\n",
- block->ino, block->bix, block->level);
- list_for_each_entry_safe(item, next, &block->item_list, list) {
- data[item->child_no] = item->val;
- list_del(&item->list);
- mempool_free(item, super->s_alias_pool);
- }
- block->page = page;
-
- if (!PagePrivate(page)) {
- SetPagePrivate(page);
- get_page(page);
- set_page_private(page, (unsigned long) block);
- }
- block->ops = &indirect_block_ops;
- initialize_block_counters(page, block, data, 0);
-}
-
-/*
- * This silences a false, yet annoying gcc warning. I hate it when my editor
- * jumps into bitops.h each time I recompile this file.
- * TODO: Complain to gcc folks about this and upgrade compiler.
- */
-static unsigned long fnb(const unsigned long *addr,
- unsigned long size, unsigned long offset)
-{
- return find_next_bit(addr, size, offset);
-}
-
-void move_page_to_btree(struct page *page)
-{
- struct logfs_block *block = logfs_block(page);
- struct super_block *sb = block->sb;
- struct logfs_super *super = logfs_super(sb);
- struct object_alias_item *item;
- unsigned long pos;
- __be64 *child;
- int err;
-
- if (super->s_flags & LOGFS_SB_FLAG_SHUTDOWN) {
- block->ops->free_block(sb, block);
- return;
- }
- log_blockmove("move_page_to_btree(%llx, %llx, %x)\n",
- block->ino, block->bix, block->level);
- super->s_flags |= LOGFS_SB_FLAG_OBJ_ALIAS;
-
- for (pos = 0; ; pos++) {
- pos = fnb(block->alias_map, LOGFS_BLOCK_FACTOR, pos);
- if (pos >= LOGFS_BLOCK_FACTOR)
- break;
-
- item = mempool_alloc(super->s_alias_pool, GFP_NOFS);
- BUG_ON(!item); /* mempool empty */
- memset(item, 0, sizeof(*item));
-
- child = kmap_atomic(page);
- item->val = child[pos];
- kunmap_atomic(child);
- item->child_no = pos;
- list_add(&item->list, &block->item_list);
- }
- block->page = NULL;
-
- if (PagePrivate(page)) {
- ClearPagePrivate(page);
- put_page(page);
- set_page_private(page, 0);
- }
- block->ops = &btree_block_ops;
- err = alias_tree_insert(block->sb, block->ino, block->bix, block->level,
- block);
- BUG_ON(err); /* mempool empty */
- ClearPageUptodate(page);
-}
-
-static int __logfs_segment_read(struct inode *inode, void *buf,
- u64 ofs, u64 bix, level_t level)
-{
- struct super_block *sb = inode->i_sb;
- void *compressor_buf = logfs_super(sb)->s_compressed_je;
- struct logfs_object_header oh;
- __be32 crc;
- u16 len;
- int err, block_len;
-
- block_len = obj_len(sb, obj_type(inode, level));
- err = read_obj_header(sb, ofs, &oh);
- if (err)
- goto out_err;
-
- err = -EIO;
- if (be64_to_cpu(oh.ino) != inode->i_ino
- || check_pos(sb, be64_to_cpu(oh.bix), bix, level)) {
- printk(KERN_ERR"LOGFS: (ino, bix) don't match at %llx: "
- "expected (%lx, %llx), got (%llx, %llx)\n",
- ofs, inode->i_ino, bix,
- be64_to_cpu(oh.ino), be64_to_cpu(oh.bix));
- goto out_err;
- }
-
- len = be16_to_cpu(oh.len);
-
- switch (oh.compr) {
- case COMPR_NONE:
- err = wbuf_read(sb, ofs + LOGFS_OBJECT_HEADERSIZE, len, buf);
- if (err)
- goto out_err;
- crc = logfs_crc32(buf, len, 0);
- if (crc != oh.data_crc) {
- printk(KERN_ERR"LOGFS: uncompressed data crc error at "
- "%llx: expected %x, got %x\n", ofs,
- be32_to_cpu(oh.data_crc),
- be32_to_cpu(crc));
- goto out_err;
- }
- break;
- case COMPR_ZLIB:
- mutex_lock(&logfs_super(sb)->s_journal_mutex);
- err = wbuf_read(sb, ofs + LOGFS_OBJECT_HEADERSIZE, len,
- compressor_buf);
- if (err) {
- mutex_unlock(&logfs_super(sb)->s_journal_mutex);
- goto out_err;
- }
- crc = logfs_crc32(compressor_buf, len, 0);
- if (crc != oh.data_crc) {
- printk(KERN_ERR"LOGFS: compressed data crc error at "
- "%llx: expected %x, got %x\n", ofs,
- be32_to_cpu(oh.data_crc),
- be32_to_cpu(crc));
- mutex_unlock(&logfs_super(sb)->s_journal_mutex);
- goto out_err;
- }
- err = logfs_uncompress(compressor_buf, buf, len, block_len);
- mutex_unlock(&logfs_super(sb)->s_journal_mutex);
- if (err) {
- printk(KERN_ERR"LOGFS: uncompress error at %llx\n", ofs);
- goto out_err;
- }
- break;
- default:
- LOGFS_BUG(sb);
- err = -EIO;
- goto out_err;
- }
- return 0;
-
-out_err:
- logfs_set_ro(sb);
- printk(KERN_ERR"LOGFS: device is read-only now\n");
- LOGFS_BUG(sb);
- return err;
-}
-
-/**
- * logfs_segment_read - read data block from object store
- * @inode: inode containing data
- * @buf: data buffer
- * @ofs: physical data offset
- * @bix: block index
- * @level: block level
- *
- * Returns 0 on success or a negative errno.
- */
-int logfs_segment_read(struct inode *inode, struct page *page,
- u64 ofs, u64 bix, level_t level)
-{
- int err;
- void *buf;
-
- if (PageUptodate(page))
- return 0;
-
- ofs &= ~LOGFS_FULLY_POPULATED;
-
- buf = kmap(page);
- err = __logfs_segment_read(inode, buf, ofs, bix, level);
- if (!err) {
- move_btree_to_page(inode, page, buf);
- SetPageUptodate(page);
- }
- kunmap(page);
- log_segment("logfs_segment_read(%lx, %llx, %x) %llx (%d)\n",
- inode->i_ino, bix, level, ofs, err);
- return err;
-}
-
-int logfs_segment_delete(struct inode *inode, struct logfs_shadow *shadow)
-{
- struct super_block *sb = inode->i_sb;
- struct logfs_super *super = logfs_super(sb);
- struct logfs_object_header h;
- u16 len;
- int err;
-
- super->s_flags |= LOGFS_SB_FLAG_DIRTY;
- BUG_ON(super->s_flags & LOGFS_SB_FLAG_SHUTDOWN);
- BUG_ON(shadow->old_ofs & LOGFS_FULLY_POPULATED);
- if (!shadow->old_ofs)
- return 0;
-
- log_segment("logfs_segment_delete(%llx, %llx, %x) %llx->%llx %x->%x\n",
- shadow->ino, shadow->bix, shadow->gc_level,
- shadow->old_ofs, shadow->new_ofs,
- shadow->old_len, shadow->new_len);
- err = read_obj_header(sb, shadow->old_ofs, &h);
- LOGFS_BUG_ON(err, sb);
- LOGFS_BUG_ON(be64_to_cpu(h.ino) != inode->i_ino, sb);
- LOGFS_BUG_ON(check_pos(sb, shadow->bix, be64_to_cpu(h.bix),
- shrink_level(shadow->gc_level)), sb);
-
- if (shadow->gc_level == 0)
- len = be16_to_cpu(h.len);
- else
- len = obj_len(sb, h.type);
- shadow->old_len = len + sizeof(h);
- return 0;
-}
-
-void freeseg(struct super_block *sb, u32 segno)
-{
- struct logfs_super *super = logfs_super(sb);
- struct address_space *mapping = super->s_mapping_inode->i_mapping;
- struct page *page;
- u64 ofs, start, end;
-
- start = dev_ofs(sb, segno, 0);
- end = dev_ofs(sb, segno + 1, 0);
- for (ofs = start; ofs < end; ofs += PAGE_SIZE) {
- page = find_get_page(mapping, ofs >> PAGE_SHIFT);
- if (!page)
- continue;
- if (PagePrivate(page)) {
- ClearPagePrivate(page);
- put_page(page);
- }
- put_page(page);
- }
-}
-
-int logfs_open_area(struct logfs_area *area, size_t bytes)
-{
- struct super_block *sb = area->a_sb;
- struct logfs_super *super = logfs_super(sb);
- int err, closed = 0;
-
- if (area->a_is_open && area->a_used_bytes + bytes <= super->s_segsize)
- return 0;
-
- if (area->a_is_open) {
- u64 ofs = dev_ofs(sb, area->a_segno, area->a_written_bytes);
- u32 len = super->s_segsize - area->a_written_bytes;
-
- log_gc("logfs_close_area(%x)\n", area->a_segno);
- pad_wbuf(area, 1);
- super->s_devops->writeseg(area->a_sb, ofs, len);
- freeseg(sb, area->a_segno);
- closed = 1;
- }
-
- area->a_used_bytes = 0;
- area->a_written_bytes = 0;
-again:
- area->a_ops->get_free_segment(area);
- area->a_ops->get_erase_count(area);
-
- log_gc("logfs_open_area(%x, %x)\n", area->a_segno, area->a_level);
- err = area->a_ops->erase_segment(area);
- if (err) {
- printk(KERN_WARNING "LogFS: Error erasing segment %x\n",
- area->a_segno);
- logfs_mark_segment_bad(sb, area->a_segno);
- goto again;
- }
- area->a_is_open = 1;
- return closed;
-}
-
-void logfs_sync_area(struct logfs_area *area)
-{
- struct super_block *sb = area->a_sb;
- struct logfs_super *super = logfs_super(sb);
- u64 ofs = dev_ofs(sb, area->a_segno, area->a_written_bytes);
- u32 len = (area->a_used_bytes - area->a_written_bytes);
-
- if (super->s_writesize)
- len &= ~(super->s_writesize - 1);
- if (len == 0)
- return;
- pad_wbuf(area, 0);
- super->s_devops->writeseg(sb, ofs, len);
- area->a_written_bytes += len;
-}
-
-void logfs_sync_segments(struct super_block *sb)
-{
- struct logfs_super *super = logfs_super(sb);
- int i;
-
- for_each_area(i)
- logfs_sync_area(super->s_area[i]);
-}
-
-/*
- * Pick a free segment to be used for this area. Effectively takes a
- * candidate from the free list (not really a candidate anymore).
- */
-static void ostore_get_free_segment(struct logfs_area *area)
-{
- struct super_block *sb = area->a_sb;
- struct logfs_super *super = logfs_super(sb);
-
- if (super->s_free_list.count == 0) {
- printk(KERN_ERR"LOGFS: ran out of free segments\n");
- LOGFS_BUG(sb);
- }
-
- area->a_segno = get_best_cand(sb, &super->s_free_list, NULL);
-}
-
-static void ostore_get_erase_count(struct logfs_area *area)
-{
- struct logfs_segment_entry se;
- u32 ec_level;
-
- logfs_get_segment_entry(area->a_sb, area->a_segno, &se);
- BUG_ON(se.ec_level == cpu_to_be32(BADSEG) ||
- se.valid == cpu_to_be32(RESERVED));
-
- ec_level = be32_to_cpu(se.ec_level);
- area->a_erase_count = (ec_level >> 4) + 1;
-}
-
-static int ostore_erase_segment(struct logfs_area *area)
-{
- struct super_block *sb = area->a_sb;
- struct logfs_segment_header sh;
- u64 ofs;
- int err;
-
- err = logfs_erase_segment(sb, area->a_segno, 0);
- if (err)
- return err;
-
- sh.pad = 0;
- sh.type = SEG_OSTORE;
- sh.level = (__force u8)area->a_level;
- sh.segno = cpu_to_be32(area->a_segno);
- sh.ec = cpu_to_be32(area->a_erase_count);
- sh.gec = cpu_to_be64(logfs_super(sb)->s_gec);
- sh.crc = logfs_crc32(&sh, sizeof(sh), 4);
-
- logfs_set_segment_erased(sb, area->a_segno, area->a_erase_count,
- area->a_level);
-
- ofs = dev_ofs(sb, area->a_segno, 0);
- area->a_used_bytes = sizeof(sh);
- logfs_buf_write(area, ofs, &sh, sizeof(sh));
- return 0;
-}
-
-static const struct logfs_area_ops ostore_area_ops = {
- .get_free_segment = ostore_get_free_segment,
- .get_erase_count = ostore_get_erase_count,
- .erase_segment = ostore_erase_segment,
-};
-
-static void free_area(struct logfs_area *area)
-{
- if (area)
- freeseg(area->a_sb, area->a_segno);
- kfree(area);
-}
-
-void free_areas(struct super_block *sb)
-{
- struct logfs_super *super = logfs_super(sb);
- int i;
-
- for_each_area(i)
- free_area(super->s_area[i]);
- free_area(super->s_journal_area);
-}
-
-static struct logfs_area *alloc_area(struct super_block *sb)
-{
- struct logfs_area *area;
-
- area = kzalloc(sizeof(*area), GFP_KERNEL);
- if (!area)
- return NULL;
-
- area->a_sb = sb;
- return area;
-}
-
-static void map_invalidatepage(struct page *page, unsigned int o,
- unsigned int l)
-{
- return;
-}
-
-static int map_releasepage(struct page *page, gfp_t g)
-{
- /* Don't release these pages */
- return 0;
-}
-
-static const struct address_space_operations mapping_aops = {
- .invalidatepage = map_invalidatepage,
- .releasepage = map_releasepage,
- .set_page_dirty = __set_page_dirty_nobuffers,
-};
-
-int logfs_init_mapping(struct super_block *sb)
-{
- struct logfs_super *super = logfs_super(sb);
- struct address_space *mapping;
- struct inode *inode;
-
- inode = logfs_new_meta_inode(sb, LOGFS_INO_MAPPING);
- if (IS_ERR(inode))
- return PTR_ERR(inode);
- super->s_mapping_inode = inode;
- mapping = inode->i_mapping;
- mapping->a_ops = &mapping_aops;
- /* Would it be possible to use __GFP_HIGHMEM as well? */
- mapping_set_gfp_mask(mapping, GFP_NOFS);
- return 0;
-}
-
-int logfs_init_areas(struct super_block *sb)
-{
- struct logfs_super *super = logfs_super(sb);
- int i = -1;
-
- super->s_alias_pool = mempool_create_kmalloc_pool(600,
- sizeof(struct object_alias_item));
- if (!super->s_alias_pool)
- return -ENOMEM;
-
- super->s_journal_area = alloc_area(sb);
- if (!super->s_journal_area)
- goto err;
-
- for_each_area(i) {
- super->s_area[i] = alloc_area(sb);
- if (!super->s_area[i])
- goto err;
- super->s_area[i]->a_level = GC_LEVEL(i);
- super->s_area[i]->a_ops = &ostore_area_ops;
- }
- btree_init_mempool128(&super->s_object_alias_tree,
- super->s_btree_pool);
- return 0;
-
-err:
- for (i--; i >= 0; i--)
- free_area(super->s_area[i]);
- free_area(super->s_journal_area);
- logfs_mempool_destroy(super->s_alias_pool);
- return -ENOMEM;
-}
-
-void logfs_cleanup_areas(struct super_block *sb)
-{
- struct logfs_super *super = logfs_super(sb);
-
- btree_grim_visitor128(&super->s_object_alias_tree, 0, kill_alias);
-}