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 Value: On success, 0 is returned. On Error, one of the following 50 * negative error code is returned. 51 * 52 * %-EIO - I/O error. 53 * 54 * %-ENOMEM - Insufficient amount of memory available. 55 * 56 * %-ENOENT - The block specified with @pbn does not exist. 57 */ 58 int nilfs_gccache_submit_read_data(struct inode *inode, sector_t blkoff, 59 sector_t pbn, __u64 vbn, 60 struct buffer_head **out_bh) 61 { 62 struct buffer_head *bh; 63 int err; 64 65 bh = nilfs_grab_buffer(inode, inode->i_mapping, blkoff, 0); 66 if (unlikely(!bh)) 67 return -ENOMEM; 68 69 if (buffer_uptodate(bh)) 70 goto out; 71 72 if (pbn == 0) { 73 struct the_nilfs *nilfs = inode->i_sb->s_fs_info; 74 75 err = nilfs_dat_translate(nilfs->ns_dat, vbn, &pbn); 76 if (unlikely(err)) { /* -EIO, -ENOMEM, -ENOENT */ 77 brelse(bh); 78 goto failed; 79 } 80 } 81 82 lock_buffer(bh); 83 if (buffer_uptodate(bh)) { 84 unlock_buffer(bh); 85 goto out; 86 } 87 88 if (!buffer_mapped(bh)) { 89 bh->b_bdev = inode->i_sb->s_bdev; 90 set_buffer_mapped(bh); 91 } 92 bh->b_blocknr = pbn; 93 bh->b_end_io = end_buffer_read_sync; 94 get_bh(bh); 95 submit_bh(REQ_OP_READ, 0, bh); 96 if (vbn) 97 bh->b_blocknr = vbn; 98 out: 99 err = 0; 100 *out_bh = bh; 101 102 failed: 103 unlock_page(bh->b_page); 104 put_page(bh->b_page); 105 return err; 106 } 107 108 /* 109 * nilfs_gccache_submit_read_node() - add node buffer and submit read request 110 * @inode - gc inode 111 * @pbn - physical block number for the block 112 * @vbn - virtual block number for the block 113 * @out_bh - indirect pointer to a buffer_head struct to receive the results 114 * 115 * Description: nilfs_gccache_submit_read_node() registers the node buffer 116 * specified by @vbn to the GC pagecache. @pbn can be supplied by the 117 * caller to avoid translation of the disk block address. 118 * 119 * Return Value: On success, 0 is returned. On Error, one of the following 120 * negative error code is returned. 121 * 122 * %-EIO - I/O error. 123 * 124 * %-ENOMEM - Insufficient amount of memory available. 125 */ 126 int nilfs_gccache_submit_read_node(struct inode *inode, sector_t pbn, 127 __u64 vbn, struct buffer_head **out_bh) 128 { 129 struct inode *btnc_inode = NILFS_I(inode)->i_assoc_inode; 130 int ret; 131 132 ret = nilfs_btnode_submit_block(btnc_inode->i_mapping, 133 vbn ? : pbn, pbn, REQ_OP_READ, 0, 134 out_bh, &pbn); 135 if (ret == -EEXIST) /* internal code (cache hit) */ 136 ret = 0; 137 return ret; 138 } 139 140 int nilfs_gccache_wait_and_mark_dirty(struct buffer_head *bh) 141 { 142 wait_on_buffer(bh); 143 if (!buffer_uptodate(bh)) { 144 struct inode *inode = bh->b_page->mapping->host; 145 146 nilfs_err(inode->i_sb, 147 "I/O error reading %s block for GC (ino=%lu, vblocknr=%llu)", 148 buffer_nilfs_node(bh) ? "node" : "data", 149 inode->i_ino, (unsigned long long)bh->b_blocknr); 150 return -EIO; 151 } 152 if (buffer_dirty(bh)) 153 return -EEXIST; 154 155 if (buffer_nilfs_node(bh) && nilfs_btree_broken_node_block(bh)) { 156 clear_buffer_uptodate(bh); 157 return -EIO; 158 } 159 mark_buffer_dirty(bh); 160 return 0; 161 } 162 163 int nilfs_init_gcinode(struct inode *inode) 164 { 165 struct nilfs_inode_info *ii = NILFS_I(inode); 166 167 inode->i_mode = S_IFREG; 168 mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS); 169 inode->i_mapping->a_ops = &empty_aops; 170 171 ii->i_flags = 0; 172 nilfs_bmap_init_gc(ii->i_bmap); 173 174 return nilfs_attach_btree_node_cache(inode); 175 } 176 177 /** 178 * nilfs_remove_all_gcinodes() - remove all unprocessed gc inodes 179 */ 180 void nilfs_remove_all_gcinodes(struct the_nilfs *nilfs) 181 { 182 struct list_head *head = &nilfs->ns_gc_inodes; 183 struct nilfs_inode_info *ii; 184 185 while (!list_empty(head)) { 186 ii = list_first_entry(head, struct nilfs_inode_info, i_dirty); 187 list_del_init(&ii->i_dirty); 188 truncate_inode_pages(&ii->vfs_inode.i_data, 0); 189 nilfs_btnode_cache_clear(ii->i_assoc_inode->i_mapping); 190 iput(&ii->vfs_inode); 191 } 192 } 193