gcinode.c

  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Dummy inodes to buffer blocks for garbage collection
  4 *
  5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
  6 *
  7 * Written by Seiji Kihara, Amagai Yoshiji, and Ryusuke Konishi.
  8 * Revised by Ryusuke Konishi.
  9 *
 10 */
 11/*
 12 * This file adds the cache of on-disk blocks to be moved in garbage
 13 * collection.  The disk blocks are held with dummy inodes (called
 14 * gcinodes), and this file provides lookup function of the dummy
 15 * inodes and their buffer read function.
 16 *
 17 * Buffers and pages held by the dummy inodes will be released each
 18 * time after they are copied to a new log.  Dirty blocks made on the
 19 * current generation and the blocks to be moved by GC never overlap
 20 * because the dirty blocks make a new generation; they rather must be
 21 * written individually.
 22 */
 23
 24#include <linux/buffer_head.h>
 25#include <linux/mpage.h>
 26#include <linux/hash.h>
 27#include <linux/slab.h>
 28#include <linux/swap.h>
 29#include "nilfs.h"
 30#include "btree.h"
 31#include "btnode.h"
 32#include "page.h"
 33#include "mdt.h"
 34#include "dat.h"
 35#include "ifile.h"
 36
 37/*
 38 * nilfs_gccache_submit_read_data() - add data buffer and submit read request
 39 * @inode - gc inode
 40 * @blkoff - dummy offset treated as the key for the page cache
 41 * @pbn - physical block number of the block
 42 * @vbn - virtual block number of the block, 0 for non-virtual block
 43 * @out_bh - indirect pointer to a buffer_head struct to receive the results
 44 *
 45 * Description: nilfs_gccache_submit_read_data() registers the data buffer
 46 * specified by @pbn to the GC pagecache with the key @blkoff.
 47 * This function sets @vbn (@pbn if @vbn is zero) in b_blocknr of the buffer.
 48 *
 49 * Return: 0 on success, or one of the following negative error codes on
 50 * failure:
 51 * * %-EIO	- I/O error (including metadata corruption).
 52 * * %-ENOENT	- The block specified with @pbn does not exist.
 53 * * %-ENOMEM	- Insufficient memory available.
 54 */
 55int nilfs_gccache_submit_read_data(struct inode *inode, sector_t blkoff,
 56				   sector_t pbn, __u64 vbn,
 57				   struct buffer_head **out_bh)
 58{
 59	struct buffer_head *bh;
 60	int err;
 61
 62	bh = nilfs_grab_buffer(inode, inode->i_mapping, blkoff, 0);
 63	if (unlikely(!bh))
 64		return -ENOMEM;
 65
 66	if (buffer_uptodate(bh))
 67		goto out;
 68
 69	if (pbn == 0) {
 70		struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 71
 72		err = nilfs_dat_translate(nilfs->ns_dat, vbn, &pbn);
 73		if (unlikely(err)) /* -EIO, -ENOMEM, -ENOENT */
 74			goto failed;
 75	}
 76
 77	lock_buffer(bh);
 78	if (buffer_uptodate(bh)) {
 79		unlock_buffer(bh);
 80		goto out;
 81	}
 82
 83	if (!buffer_mapped(bh))
 84		set_buffer_mapped(bh);
 85	bh->b_blocknr = pbn;
 86	bh->b_end_io = end_buffer_read_sync;
 87	get_bh(bh);
 88	submit_bh(REQ_OP_READ, bh);
 89	if (vbn)
 90		bh->b_blocknr = vbn;
 91 out:
 92	err = 0;
 93	*out_bh = bh;
 94
 95 failed:
 96	folio_unlock(bh->b_folio);
 97	folio_put(bh->b_folio);
 98	if (unlikely(err))
 99		brelse(bh);
100	return err;
101}
102
103/*
104 * nilfs_gccache_submit_read_node() - add node buffer and submit read request
105 * @inode - gc inode
106 * @pbn - physical block number for the block
107 * @vbn - virtual block number for the block
108 * @out_bh - indirect pointer to a buffer_head struct to receive the results
109 *
110 * Description: nilfs_gccache_submit_read_node() registers the node buffer
111 * specified by @vbn to the GC pagecache.  @pbn can be supplied by the
112 * caller to avoid translation of the disk block address.
113 *
114 * Return: 0 on success, or one of the following negative error codes on
115 * failure:
116 * * %-EIO	- I/O error (including metadata corruption).
117 * * %-ENOENT	- Invalid virtual block address.
118 * * %-ENOMEM	- Insufficient memory available.
119 */
120int nilfs_gccache_submit_read_node(struct inode *inode, sector_t pbn,
121				   __u64 vbn, struct buffer_head **out_bh)
122{
123	struct inode *btnc_inode = NILFS_I(inode)->i_assoc_inode;
124	int ret;
125
126	ret = nilfs_btnode_submit_block(btnc_inode->i_mapping, vbn ? : pbn, pbn,
127					REQ_OP_READ, out_bh, &pbn);
128	if (ret == -EEXIST) /* internal code (cache hit) */
129		ret = 0;
130	return ret;
131}
132
133int nilfs_gccache_wait_and_mark_dirty(struct buffer_head *bh)
134{
135	wait_on_buffer(bh);
136	if (!buffer_uptodate(bh)) {
137		struct inode *inode = bh->b_folio->mapping->host;
138
139		nilfs_err(inode->i_sb,
140			  "I/O error reading %s block for GC (ino=%lu, vblocknr=%llu)",
141			  buffer_nilfs_node(bh) ? "node" : "data",
142			  inode->i_ino, (unsigned long long)bh->b_blocknr);
143		return -EIO;
144	}
145	if (buffer_dirty(bh))
146		return -EEXIST;
147
148	if (buffer_nilfs_node(bh) && nilfs_btree_broken_node_block(bh)) {
149		clear_buffer_uptodate(bh);
150		return -EIO;
151	}
152	mark_buffer_dirty(bh);
153	return 0;
154}
155
156int nilfs_init_gcinode(struct inode *inode)
157{
158	struct nilfs_inode_info *ii = NILFS_I(inode);
159
160	inode->i_mode = S_IFREG;
161	mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
162	inode->i_mapping->a_ops = &nilfs_buffer_cache_aops;
163
164	ii->i_flags = 0;
165	nilfs_bmap_init_gc(ii->i_bmap);
166
167	return nilfs_attach_btree_node_cache(inode);
168}
169
170/**
171 * nilfs_remove_all_gcinodes() - remove all unprocessed gc inodes
172 * @nilfs: NILFS filesystem instance
173 */
174void nilfs_remove_all_gcinodes(struct the_nilfs *nilfs)
175{
176	struct list_head *head = &nilfs->ns_gc_inodes;
177	struct nilfs_inode_info *ii;
178
179	while (!list_empty(head)) {
180		ii = list_first_entry(head, struct nilfs_inode_info, i_dirty);
181		list_del_init(&ii->i_dirty);
182		truncate_inode_pages(&ii->vfs_inode.i_data, 0);
183		nilfs_btnode_cache_clear(ii->i_assoc_inode->i_mapping);
184		iput(&ii->vfs_inode);
185	}
186}