This adds roll-forward routines to recover fsynced data. - F2FS uses basically roll-back model with checkpointing. - In order to implement fsync(), there are two approaches as follows. 1. A roll-back model with checkpointing at every fsync() : This is a naive method, but suffers from very low performance. 2. A roll-forward model : F2FS adopts this model where all the fsynced data should be recovered, which were written after checkpointing was done. In order to figure out the data, F2FS keeps a "fsync" mark in direct node blocks. In addition, F2FS remains the location of next node block in each direct node block for reconstructing the chain of node blocks during the recovery. - In order to enhance the performance, F2FS keeps a "dentry" mark also in direct node blocks. If this is set during the recovery, F2FS replays adding a dentry. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@xxxxxxxxxxx> --- fs/f2fs/recovery.c | 375 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 375 insertions(+) create mode 100644 fs/f2fs/recovery.c diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c new file mode 100644 index 0000000..59b6331 --- /dev/null +++ b/fs/f2fs/recovery.c @@ -0,0 +1,375 @@ +/** + * fs/f2fs/recovery.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 "f2fs.h" +#include "node.h" +#include "segment.h" + +static struct kmem_cache *fsync_entry_slab; + +bool space_for_roll_forward(struct f2fs_sb_info *sbi) +{ + if (sbi->last_valid_block_count + sbi->alloc_valid_block_count + > sbi->user_block_count) + return false; + return true; +} + +static struct fsync_inode_entry *get_fsync_inode(struct list_head *head, + nid_t ino) +{ + struct list_head *this; + struct fsync_inode_entry *entry; + + list_for_each(this, head) { + entry = list_entry(this, struct fsync_inode_entry, list); + if (entry->inode->i_ino == ino) + return entry; + } + return NULL; +} + +static int recover_dentry(struct page *ipage, struct inode *inode) +{ + struct f2fs_node *raw_node = (struct f2fs_node *)kmap(ipage); + struct f2fs_inode *raw_inode = &(raw_node->i); + struct dentry dent, parent; + struct f2fs_dir_entry *de; + struct page *page; + struct inode *dir; + int err = 0; + + if (!is_dent_dnode(ipage)) + goto out; + + dir = f2fs_iget(inode->i_sb, le32_to_cpu(raw_inode->i_pino)); + if (IS_ERR(dir)) { + err = -EINVAL; + goto out; + } + + parent.d_inode = dir; + dent.d_parent = &parent; + dent.d_name.len = le32_to_cpu(raw_inode->i_namelen); + dent.d_name.name = raw_inode->i_name; + + de = f2fs_find_entry(dir, &dent.d_name, &page); + if (de) { + kunmap(page); + f2fs_put_page(page, 0); + } else { + f2fs_add_link(&dent, inode); + } + iput(dir); +out: + kunmap(ipage); + return err; +} + +static int recover_inode(struct inode *inode, struct page *node_page) +{ + void *kaddr = page_address(node_page); + struct f2fs_node *raw_node = (struct f2fs_node *)kaddr; + struct f2fs_inode *raw_inode = &(raw_node->i); + + inode->i_mode = le32_to_cpu(raw_inode->i_mode); + i_size_write(inode, le64_to_cpu(raw_inode->i_size)); + inode->i_atime.tv_sec = le64_to_cpu(raw_inode->i_mtime); + inode->i_ctime.tv_sec = le64_to_cpu(raw_inode->i_ctime); + inode->i_mtime.tv_sec = le64_to_cpu(raw_inode->i_mtime); + inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec); + inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec); + inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec); + + return recover_dentry(node_page, inode); +} + +static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head) +{ + unsigned long long cp_ver = le64_to_cpu(sbi->ckpt->checkpoint_ver); + struct curseg_info *curseg; + struct page *page; + block_t blkaddr; + int err = 0; + + /* get node pages in the current segment */ + curseg = CURSEG_I(sbi, CURSEG_WARM_NODE); + blkaddr = START_BLOCK(sbi, curseg->segno) + curseg->next_blkoff; + + /* read node page */ + page = alloc_page(GFP_NOFS | __GFP_ZERO); + if (IS_ERR(page)) + return PTR_ERR(page); + lock_page(page); + + while (1) { + struct fsync_inode_entry *entry; + + if (f2fs_readpage(sbi, page, blkaddr, READ_SYNC)) + goto out; + + if (cp_ver != cpver_of_node(page)) + goto out; + + if (!is_fsync_dnode(page)) + goto next; + + entry = get_fsync_inode(head, ino_of_node(page)); + if (entry) { + entry->blkaddr = blkaddr; + if (IS_INODE(page) && is_dent_dnode(page)) + set_inode_flag(F2FS_I(entry->inode), + FI_INC_LINK); + } else { + if (IS_INODE(page) && is_dent_dnode(page)) { + if (recover_inode_page(sbi, page)) { + err = -ENOMEM; + goto out; + } + } + + /* add this fsync inode to the list */ + entry = kmem_cache_alloc(fsync_entry_slab, GFP_NOFS); + if (!entry) { + err = -ENOMEM; + goto out; + } + + INIT_LIST_HEAD(&entry->list); + list_add_tail(&entry->list, head); + + entry->inode = f2fs_iget(sbi->sb, ino_of_node(page)); + if (IS_ERR(entry->inode)) { + err = PTR_ERR(entry->inode); + goto out; + } + entry->blkaddr = blkaddr; + } + if (IS_INODE(page)) { + err = recover_inode(entry->inode, page); + if (err) + goto out; + } +next: + /* check next segment */ + blkaddr = next_blkaddr_of_node(page); + ClearPageUptodate(page); + } +out: + unlock_page(page); + __free_pages(page, 0); + return err; +} + +static void destroy_fsync_dnodes(struct f2fs_sb_info *sbi, + struct list_head *head) +{ + struct list_head *this; + struct fsync_inode_entry *entry; + list_for_each(this, head) { + entry = list_entry(this, struct fsync_inode_entry, list); + iput(entry->inode); + list_del(&entry->list); + kmem_cache_free(fsync_entry_slab, entry); + } +} + +static void check_index_in_prev_nodes(struct f2fs_sb_info *sbi, + block_t blkaddr) +{ + struct seg_entry *sentry; + unsigned int segno = GET_SEGNO(sbi, blkaddr); + unsigned short blkoff = GET_SEGOFF_FROM_SEG0(sbi, blkaddr) & + (sbi->blocks_per_seg - 1); + struct f2fs_summary sum; + nid_t ino; + void *kaddr; + struct inode *inode; + struct page *node_page; + block_t bidx; + int i; + + sentry = get_seg_entry(sbi, segno); + if (!f2fs_test_bit(blkoff, sentry->cur_valid_map)) + return; + + /* Get the previous summary */ + for (i = CURSEG_WARM_DATA; i <= CURSEG_COLD_DATA; i++) { + struct curseg_info *curseg = CURSEG_I(sbi, i); + if (curseg->segno == segno) { + sum = curseg->sum_blk->entries[blkoff]; + break; + } + } + if (i > CURSEG_COLD_DATA) { + struct page *sum_page = get_sum_page(sbi, segno); + struct f2fs_summary_block *sum_node; + kaddr = page_address(sum_page); + sum_node = (struct f2fs_summary_block *)kaddr; + sum = sum_node->entries[blkoff]; + f2fs_put_page(sum_page, 1); + } + + /* Get the node page */ + node_page = get_node_page(sbi, le32_to_cpu(sum.nid)); + bidx = start_bidx_of_node(ofs_of_node(node_page)) + + le16_to_cpu(sum.ofs_in_node); + ino = ino_of_node(node_page); + f2fs_put_page(node_page, 1); + + /* Deallocate previous index in the node page */ + inode = f2fs_iget_nowait(sbi->sb, ino); + truncate_hole(inode, bidx, bidx + 1); + iput(inode); +} + +static void do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode, + struct page *page, block_t blkaddr) +{ + unsigned int start, end; + struct dnode_of_data dn; + struct f2fs_summary sum; + struct node_info ni; + + start = start_bidx_of_node(ofs_of_node(page)); + if (IS_INODE(page)) + end = start + ADDRS_PER_INODE; + else + end = start + ADDRS_PER_BLOCK; + + set_new_dnode(&dn, inode, NULL, NULL, 0); + if (get_dnode_of_data(&dn, start, 0)) + return; + + wait_on_page_writeback(dn.node_page); + + get_node_info(sbi, dn.nid, &ni); + BUG_ON(ni.ino != ino_of_node(page)); + BUG_ON(ofs_of_node(dn.node_page) != ofs_of_node(page)); + + for (; start < end; start++) { + block_t src, dest; + + src = datablock_addr(dn.node_page, dn.ofs_in_node); + dest = datablock_addr(page, dn.ofs_in_node); + + if (src != dest && dest != NEW_ADDR && dest != NULL_ADDR) { + if (src == NULL_ADDR) { + int err = reserve_new_block(&dn); + /* We should not get -ENOSPC */ + BUG_ON(err); + } + + /* Check the previous node page having this index */ + check_index_in_prev_nodes(sbi, dest); + + set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version); + + /* write dummy data page */ + recover_data_page(sbi, NULL, &sum, src, dest); + update_extent_cache(dest, &dn); + } + dn.ofs_in_node++; + } + + /* write node page in place */ + set_summary(&sum, dn.nid, 0, 0); + if (IS_INODE(dn.node_page)) + sync_inode_page(&dn); + + copy_node_footer(dn.node_page, page); + fill_node_footer(dn.node_page, dn.nid, ni.ino, + ofs_of_node(page), false); + set_page_dirty(dn.node_page); + + recover_node_page(sbi, dn.node_page, &sum, &ni, blkaddr); + f2fs_put_dnode(&dn); +} + +static void recover_data(struct f2fs_sb_info *sbi, + struct list_head *head, int type) +{ + unsigned long long cp_ver = le64_to_cpu(sbi->ckpt->checkpoint_ver); + struct curseg_info *curseg; + struct page *page; + block_t blkaddr; + + /* get node pages in the current segment */ + curseg = CURSEG_I(sbi, type); + blkaddr = NEXT_FREE_BLKADDR(sbi, curseg); + + /* read node page */ + page = alloc_page(GFP_NOFS | __GFP_ZERO); + if (IS_ERR(page)) + return; + lock_page(page); + + while (1) { + struct fsync_inode_entry *entry; + + if (f2fs_readpage(sbi, page, blkaddr, READ_SYNC)) + goto out; + + if (cp_ver != cpver_of_node(page)) + goto out; + + entry = get_fsync_inode(head, ino_of_node(page)); + if (!entry) + goto next; + + do_recover_data(sbi, entry->inode, page, blkaddr); + + if (entry->blkaddr == blkaddr) { + iput(entry->inode); + list_del(&entry->list); + kmem_cache_free(fsync_entry_slab, entry); + } +next: + /* check next segment */ + blkaddr = next_blkaddr_of_node(page); + ClearPageUptodate(page); + } +out: + unlock_page(page); + __free_pages(page, 0); + + allocate_new_segments(sbi); +} + +void recover_fsync_data(struct f2fs_sb_info *sbi) +{ + struct list_head inode_list; + + fsync_entry_slab = f2fs_kmem_cache_create("f2fs_fsync_inode_entry", + sizeof(struct fsync_inode_entry), NULL); + if (unlikely(!fsync_entry_slab)) + return; + + INIT_LIST_HEAD(&inode_list); + + /* step #1: find fsynced inode numbers */ + if (find_fsync_dnodes(sbi, &inode_list)) + goto out; + + if (list_empty(&inode_list)) + goto out; + + /* step #2: recover data */ + sbi->por_doing = 1; + recover_data(sbi, &inode_list, CURSEG_WARM_NODE); + sbi->por_doing = 0; + BUG_ON(!list_empty(&inode_list)); +out: + destroy_fsync_dnodes(sbi, &inode_list); + kmem_cache_destroy(fsync_entry_slab); + write_checkpoint(sbi, false, false); +} -- 1.7.9.5 --- Jaegeuk Kim Samsung -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
