linux_dsm_epyc7002/fs/f2fs/recovery.c
Jaegeuk Kim d4686d56ec f2fs: avoid balanc_fs during evict_inode
1. Background

Previously, if f2fs tries to move data blocks of an *evicting* inode during the
cleaning process, it stops the process incompletely and then restarts the whole
process, since it needs a locked inode to grab victim data pages in its address
space. In order to get a locked inode, iget_locked() by f2fs_iget() is normally
used, but, it waits if the inode is on freeing.

So, here is a deadlock scenario.
1. f2fs_evict_inode()       <- inode "A"
  2. f2fs_balance_fs()
    3. f2fs_gc()
      4. gc_data_segment()
        5. f2fs_iget()      <- inode "A" too!

If step #1 and #5 treat a same inode "A", step #5 would fall into deadlock since
the inode "A" is on freeing. In order to resolve this, f2fs_iget_nowait() which
skips __wait_on_freeing_inode() was introduced in step #5, and stops f2fs_gc()
to complete f2fs_evict_inode().

1. f2fs_evict_inode()           <- inode "A"
  2. f2fs_balance_fs()
    3. f2fs_gc()
      4. gc_data_segment()
        5. f2fs_iget_nowait()   <- inode "A", then stop f2fs_gc() w/ -ENOENT

2. Problem and Solution

In the above scenario, however, f2fs cannot finish f2fs_evict_inode() only if:
 o there are not enough free sections, and
 o f2fs_gc() tries to move data blocks of the *evicting* inode repeatedly.

So, the final solution is to use f2fs_iget() and remove f2fs_balance_fs() in
f2fs_evict_inode().
The f2fs_evict_inode() actually truncates all the data and node blocks, which
means that it doesn't produce any dirty node pages accordingly.
So, we don't need to do f2fs_balance_fs() in practical.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:15:01 +09:00

378 lines
9.1 KiB
C

/*
* 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 {
err = 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 = le16_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_F2FS_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;
}
entry->inode = f2fs_iget(sbi->sb, ino_of_node(page));
if (IS_ERR(entry->inode)) {
err = PTR_ERR(entry->inode);
kmem_cache_free(fsync_entry_slab, entry);
goto out;
}
list_add_tail(&entry->list, head);
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 fsync_inode_entry *entry, *tmp;
list_for_each_entry_safe(entry, tmp, head, 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(sbi->sb, ino);
if (IS_ERR(inode))
return;
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);
}