path: root/fs/f2fs/recovery.c

// SPDX-License-Identifier: GPL-2.0
/*
 * fs/f2fs/recovery.c
 *
 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
 *             http://www.samsung.com/
 */
#include <linux/unaligned.h>
#include <linux/fs.h>
#include <linux/f2fs_fs.h>
#include <linux/sched/mm.h>
#include "f2fs.h"
#include "node.h"
#include "segment.h"

/*
 * Roll forward recovery scenarios.
 *
 * [Term] F: fsync_mark, D: dentry_mark
 *
 * 1. inode(x) | CP | inode(x) | dnode(F)
 * -> Update the latest inode(x).
 *
 * 2. inode(x) | CP | inode(F) | dnode(F)
 * -> No problem.
 *
 * 3. inode(x) | CP | dnode(F) | inode(x)
 * -> Recover to the latest dnode(F), and drop the last inode(x)
 *
 * 4. inode(x) | CP | dnode(F) | inode(F)
 * -> No problem.
 *
 * 5. CP | inode(x) | dnode(F)
 * -> The inode(DF) was missing. Should drop this dnode(F).
 *
 * 6. CP | inode(DF) | dnode(F)
 * -> No problem.
 *
 * 7. CP | dnode(F) | inode(DF)
 * -> If f2fs_iget fails, then goto next to find inode(DF).
 *
 * 8. CP | dnode(F) | inode(x)
 * -> If f2fs_iget fails, then goto next to find inode(DF).
 *    But it will fail due to no inode(DF).
 */

static struct kmem_cache *fsync_entry_slab;

bool f2fs_space_for_roll_forward(struct f2fs_sb_info *sbi)
{
	s64 nalloc = percpu_counter_sum_positive(&sbi->alloc_valid_block_count);

	if (sbi->last_valid_block_count + nalloc > sbi->user_block_count)
		return false;
	if (NM_I(sbi)->max_rf_node_blocks &&
		percpu_counter_sum_positive(&sbi->rf_node_block_count) >=
						NM_I(sbi)->max_rf_node_blocks)
		return false;
	return true;
}

static struct fsync_inode_entry *get_fsync_inode(struct list_head *head,
								nid_t ino)
{
	struct fsync_inode_entry *entry;

	list_for_each_entry(entry, head, list)
		if (entry->inode->i_ino == ino)
			return entry;

	return NULL;
}

static struct fsync_inode_entry *add_fsync_inode(struct f2fs_sb_info *sbi,
			struct list_head *head, nid_t ino, bool quota_inode)
{
	struct inode *inode;
	struct fsync_inode_entry *entry;
	int err;

	inode = f2fs_iget_retry(sbi->sb, ino);
	if (IS_ERR(inode))
		return ERR_CAST(inode);

	err = f2fs_dquot_initialize(inode);
	if (err)
		goto err_out;

	if (quota_inode) {
		err = dquot_alloc_inode(inode);
		if (err)
			goto err_out;
	}

	entry = f2fs_kmem_cache_alloc(fsync_entry_slab,
					GFP_F2FS_ZERO, true, NULL);
	entry->inode = inode;
	list_add_tail(&entry->list, head);

	return entry;
err_out:
	iput(inode);
	return ERR_PTR(err);
}

static void del_fsync_inode(struct fsync_inode_entry *entry, int drop)
{
	if (drop) {
		/* inode should not be recovered, drop it */
		f2fs_inode_synced(entry->inode);
	}
	iput(entry->inode);
	list_del(&entry->list);
	kmem_cache_free(fsync_entry_slab, entry);
}

static int init_recovered_filename(const struct inode *dir,
				   struct f2fs_inode *raw_inode,
				   struct f2fs_filename *fname,
				   struct qstr *usr_fname)
{
	int err;

	memset(fname, 0, sizeof(*fname));
	fname->disk_name.len = le32_to_cpu(raw_inode->i_namelen);
	fname->disk_name.name = raw_inode->i_name;

	if (WARN_ON(fname->disk_name.len > F2FS_NAME_LEN))
		return -ENAMETOOLONG;

	if (!IS_ENCRYPTED(dir)) {
		usr_fname->name = fname->disk_name.name;
		usr_fname->len = fname->disk_name.len;
		fname->usr_fname = usr_fname;
	}

	/* Compute the hash of the filename */
	if (IS_ENCRYPTED(dir) && IS_CASEFOLDED(dir)) {
		/*
		 * In this case the hash isn't computable without the key, so it
		 * was saved on-disk.
		 */
		if (fname->disk_name.len + sizeof(f2fs_hash_t) > F2FS_NAME_LEN)
			return -EINVAL;
		fname->hash = get_unaligned((f2fs_hash_t *)
				&raw_inode->i_name[fname->disk_name.len]);
	} else if (IS_CASEFOLDED(dir)) {
		err = f2fs_init_casefolded_name(dir, fname);
		if (err)
			return err;
		f2fs_hash_filename(dir, fname);
		/* Case-sensitive match is fine for recovery */
		f2fs_free_casefolded_name(fname);
	} else {
		f2fs_hash_filename(dir, fname);
	}
	return 0;
}

static int recover_dentry(struct inode *inode, struct folio *ifolio,
						struct list_head *dir_list)
{
	struct f2fs_inode *raw_inode = F2FS_INODE(ifolio);