Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 1 | /* |
| 2 | * btnode.c - NILFS B-tree node cache |
| 3 | * |
| 4 | * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * along with this program; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | * |
| 20 | * This file was originally written by Seiji Kihara <kihara@osrg.net> |
| 21 | * and fully revised by Ryusuke Konishi <ryusuke@osrg.net> for |
| 22 | * stabilization and simplification. |
| 23 | * |
| 24 | */ |
| 25 | |
| 26 | #include <linux/types.h> |
| 27 | #include <linux/buffer_head.h> |
| 28 | #include <linux/mm.h> |
| 29 | #include <linux/backing-dev.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 30 | #include <linux/gfp.h> |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 31 | #include "nilfs.h" |
| 32 | #include "mdt.h" |
| 33 | #include "dat.h" |
| 34 | #include "page.h" |
| 35 | #include "btnode.h" |
| 36 | |
| 37 | |
| 38 | void nilfs_btnode_cache_init_once(struct address_space *btnc) |
| 39 | { |
Ryusuke Konishi | ebdfed4 | 2010-09-06 12:05:43 +0900 | [diff] [blame] | 40 | nilfs_mapping_init_once(btnc); |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 41 | } |
| 42 | |
Alexey Dobriyan | 7f09410 | 2009-09-21 17:01:10 -0700 | [diff] [blame] | 43 | static const struct address_space_operations def_btnode_aops = { |
Ryusuke Konishi | fa03274 | 2009-05-27 22:44:34 +0900 | [diff] [blame] | 44 | .sync_page = block_sync_page, |
| 45 | }; |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 46 | |
Ryusuke Konishi | a53b475 | 2009-05-27 22:11:46 +0900 | [diff] [blame] | 47 | void nilfs_btnode_cache_init(struct address_space *btnc, |
| 48 | struct backing_dev_info *bdi) |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 49 | { |
Ryusuke Konishi | ebdfed4 | 2010-09-06 12:05:43 +0900 | [diff] [blame] | 50 | nilfs_mapping_init(btnc, bdi, &def_btnode_aops); |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 51 | } |
| 52 | |
| 53 | void nilfs_btnode_cache_clear(struct address_space *btnc) |
| 54 | { |
| 55 | invalidate_mapping_pages(btnc, 0, -1); |
| 56 | truncate_inode_pages(btnc, 0); |
| 57 | } |
| 58 | |
Ryusuke Konishi | d501d73 | 2009-11-13 16:04:11 +0900 | [diff] [blame] | 59 | struct buffer_head * |
| 60 | nilfs_btnode_create_block(struct address_space *btnc, __u64 blocknr) |
| 61 | { |
| 62 | struct inode *inode = NILFS_BTNC_I(btnc); |
| 63 | struct buffer_head *bh; |
| 64 | |
| 65 | bh = nilfs_grab_buffer(inode, btnc, blocknr, 1 << BH_NILFS_Node); |
| 66 | if (unlikely(!bh)) |
| 67 | return NULL; |
| 68 | |
| 69 | if (unlikely(buffer_mapped(bh) || buffer_uptodate(bh) || |
| 70 | buffer_dirty(bh))) { |
| 71 | brelse(bh); |
| 72 | BUG(); |
| 73 | } |
| 74 | memset(bh->b_data, 0, 1 << inode->i_blkbits); |
| 75 | bh->b_bdev = NILFS_I_NILFS(inode)->ns_bdev; |
| 76 | bh->b_blocknr = blocknr; |
| 77 | set_buffer_mapped(bh); |
| 78 | set_buffer_uptodate(bh); |
| 79 | |
| 80 | unlock_page(bh->b_page); |
| 81 | page_cache_release(bh->b_page); |
| 82 | return bh; |
| 83 | } |
| 84 | |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 85 | int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr, |
Ryusuke Konishi | 26dfdd8 | 2010-07-18 10:42:23 +0900 | [diff] [blame] | 86 | sector_t pblocknr, int mode, |
| 87 | struct buffer_head **pbh, sector_t *submit_ptr) |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 88 | { |
| 89 | struct buffer_head *bh; |
| 90 | struct inode *inode = NILFS_BTNC_I(btnc); |
Ryusuke Konishi | f8e6cc0 | 2010-07-15 11:39:10 +0900 | [diff] [blame] | 91 | struct page *page; |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 92 | int err; |
| 93 | |
| 94 | bh = nilfs_grab_buffer(inode, btnc, blocknr, 1 << BH_NILFS_Node); |
| 95 | if (unlikely(!bh)) |
| 96 | return -ENOMEM; |
| 97 | |
| 98 | err = -EEXIST; /* internal code */ |
Ryusuke Konishi | f8e6cc0 | 2010-07-15 11:39:10 +0900 | [diff] [blame] | 99 | page = bh->b_page; |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 100 | |
| 101 | if (buffer_uptodate(bh) || buffer_dirty(bh)) |
| 102 | goto found; |
| 103 | |
| 104 | if (pblocknr == 0) { |
| 105 | pblocknr = blocknr; |
| 106 | if (inode->i_ino != NILFS_DAT_INO) { |
| 107 | struct inode *dat = |
| 108 | nilfs_dat_inode(NILFS_I_NILFS(inode)); |
| 109 | |
| 110 | /* blocknr is a virtual block number */ |
| 111 | err = nilfs_dat_translate(dat, blocknr, &pblocknr); |
| 112 | if (unlikely(err)) { |
| 113 | brelse(bh); |
| 114 | goto out_locked; |
| 115 | } |
| 116 | } |
| 117 | } |
Ryusuke Konishi | 26dfdd8 | 2010-07-18 10:42:23 +0900 | [diff] [blame] | 118 | |
| 119 | if (mode == READA) { |
| 120 | if (pblocknr != *submit_ptr + 1 || !trylock_buffer(bh)) { |
| 121 | err = -EBUSY; /* internal code */ |
| 122 | brelse(bh); |
| 123 | goto out_locked; |
| 124 | } |
| 125 | } else { /* mode == READ */ |
| 126 | lock_buffer(bh); |
| 127 | } |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 128 | if (buffer_uptodate(bh)) { |
| 129 | unlock_buffer(bh); |
| 130 | err = -EEXIST; /* internal code */ |
| 131 | goto found; |
| 132 | } |
| 133 | set_buffer_mapped(bh); |
| 134 | bh->b_bdev = NILFS_I_NILFS(inode)->ns_bdev; |
| 135 | bh->b_blocknr = pblocknr; /* set block address for read */ |
| 136 | bh->b_end_io = end_buffer_read_sync; |
| 137 | get_bh(bh); |
Ryusuke Konishi | 26dfdd8 | 2010-07-18 10:42:23 +0900 | [diff] [blame] | 138 | submit_bh(mode, bh); |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 139 | bh->b_blocknr = blocknr; /* set back to the given block address */ |
Ryusuke Konishi | 26dfdd8 | 2010-07-18 10:42:23 +0900 | [diff] [blame] | 140 | *submit_ptr = pblocknr; |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 141 | err = 0; |
| 142 | found: |
| 143 | *pbh = bh; |
| 144 | |
| 145 | out_locked: |
Ryusuke Konishi | f8e6cc0 | 2010-07-15 11:39:10 +0900 | [diff] [blame] | 146 | unlock_page(page); |
| 147 | page_cache_release(page); |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 148 | return err; |
| 149 | } |
| 150 | |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 151 | /** |
| 152 | * nilfs_btnode_delete - delete B-tree node buffer |
| 153 | * @bh: buffer to be deleted |
| 154 | * |
| 155 | * nilfs_btnode_delete() invalidates the specified buffer and delete the page |
| 156 | * including the buffer if the page gets unbusy. |
| 157 | */ |
| 158 | void nilfs_btnode_delete(struct buffer_head *bh) |
| 159 | { |
| 160 | struct address_space *mapping; |
| 161 | struct page *page = bh->b_page; |
| 162 | pgoff_t index = page_index(page); |
| 163 | int still_dirty; |
| 164 | |
| 165 | page_cache_get(page); |
| 166 | lock_page(page); |
| 167 | wait_on_page_writeback(page); |
| 168 | |
| 169 | nilfs_forget_buffer(bh); |
| 170 | still_dirty = PageDirty(page); |
| 171 | mapping = page->mapping; |
| 172 | unlock_page(page); |
| 173 | page_cache_release(page); |
| 174 | |
| 175 | if (!still_dirty && mapping) |
| 176 | invalidate_inode_pages2_range(mapping, index, index); |
| 177 | } |
| 178 | |
| 179 | /** |
| 180 | * nilfs_btnode_prepare_change_key |
| 181 | * prepare to move contents of the block for old key to one of new key. |
| 182 | * the old buffer will not be removed, but might be reused for new buffer. |
| 183 | * it might return -ENOMEM because of memory allocation errors, |
| 184 | * and might return -EIO because of disk read errors. |
| 185 | */ |
| 186 | int nilfs_btnode_prepare_change_key(struct address_space *btnc, |
| 187 | struct nilfs_btnode_chkey_ctxt *ctxt) |
| 188 | { |
| 189 | struct buffer_head *obh, *nbh; |
| 190 | struct inode *inode = NILFS_BTNC_I(btnc); |
| 191 | __u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey; |
| 192 | int err; |
| 193 | |
| 194 | if (oldkey == newkey) |
| 195 | return 0; |
| 196 | |
| 197 | obh = ctxt->bh; |
| 198 | ctxt->newbh = NULL; |
| 199 | |
| 200 | if (inode->i_blkbits == PAGE_CACHE_SHIFT) { |
| 201 | lock_page(obh->b_page); |
| 202 | /* |
| 203 | * We cannot call radix_tree_preload for the kernels older |
| 204 | * than 2.6.23, because it is not exported for modules. |
| 205 | */ |
Ryusuke Konishi | b1f1b8c | 2009-08-30 04:21:41 +0900 | [diff] [blame] | 206 | retry: |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 207 | err = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM); |
| 208 | if (err) |
| 209 | goto failed_unlock; |
| 210 | /* BUG_ON(oldkey != obh->b_page->index); */ |
| 211 | if (unlikely(oldkey != obh->b_page->index)) |
| 212 | NILFS_PAGE_BUG(obh->b_page, |
| 213 | "invalid oldkey %lld (newkey=%lld)", |
| 214 | (unsigned long long)oldkey, |
| 215 | (unsigned long long)newkey); |
| 216 | |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 217 | spin_lock_irq(&btnc->tree_lock); |
| 218 | err = radix_tree_insert(&btnc->page_tree, newkey, obh->b_page); |
| 219 | spin_unlock_irq(&btnc->tree_lock); |
| 220 | /* |
| 221 | * Note: page->index will not change to newkey until |
| 222 | * nilfs_btnode_commit_change_key() will be called. |
| 223 | * To protect the page in intermediate state, the page lock |
| 224 | * is held. |
| 225 | */ |
| 226 | radix_tree_preload_end(); |
| 227 | if (!err) |
| 228 | return 0; |
| 229 | else if (err != -EEXIST) |
| 230 | goto failed_unlock; |
| 231 | |
| 232 | err = invalidate_inode_pages2_range(btnc, newkey, newkey); |
| 233 | if (!err) |
| 234 | goto retry; |
| 235 | /* fallback to copy mode */ |
| 236 | unlock_page(obh->b_page); |
| 237 | } |
| 238 | |
Ryusuke Konishi | 45f4910 | 2009-11-13 16:25:19 +0900 | [diff] [blame] | 239 | nbh = nilfs_btnode_create_block(btnc, newkey); |
| 240 | if (!nbh) |
| 241 | return -ENOMEM; |
| 242 | |
| 243 | BUG_ON(nbh == obh); |
| 244 | ctxt->newbh = nbh; |
| 245 | return 0; |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 246 | |
| 247 | failed_unlock: |
| 248 | unlock_page(obh->b_page); |
| 249 | return err; |
| 250 | } |
| 251 | |
| 252 | /** |
| 253 | * nilfs_btnode_commit_change_key |
| 254 | * commit the change_key operation prepared by prepare_change_key(). |
| 255 | */ |
| 256 | void nilfs_btnode_commit_change_key(struct address_space *btnc, |
| 257 | struct nilfs_btnode_chkey_ctxt *ctxt) |
| 258 | { |
| 259 | struct buffer_head *obh = ctxt->bh, *nbh = ctxt->newbh; |
| 260 | __u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey; |
| 261 | struct page *opage; |
| 262 | |
| 263 | if (oldkey == newkey) |
| 264 | return; |
| 265 | |
| 266 | if (nbh == NULL) { /* blocksize == pagesize */ |
| 267 | opage = obh->b_page; |
| 268 | if (unlikely(oldkey != opage->index)) |
| 269 | NILFS_PAGE_BUG(opage, |
| 270 | "invalid oldkey %lld (newkey=%lld)", |
| 271 | (unsigned long long)oldkey, |
| 272 | (unsigned long long)newkey); |
Ryusuke Konishi | b1e19e5 | 2009-11-03 00:25:53 +0900 | [diff] [blame] | 273 | nilfs_btnode_mark_dirty(obh); |
Ryusuke Konishi | a60be98 | 2009-04-06 19:01:25 -0700 | [diff] [blame] | 274 | |
| 275 | spin_lock_irq(&btnc->tree_lock); |
| 276 | radix_tree_delete(&btnc->page_tree, oldkey); |
| 277 | radix_tree_tag_set(&btnc->page_tree, newkey, |
| 278 | PAGECACHE_TAG_DIRTY); |
| 279 | spin_unlock_irq(&btnc->tree_lock); |
| 280 | |
| 281 | opage->index = obh->b_blocknr = newkey; |
| 282 | unlock_page(opage); |
| 283 | } else { |
| 284 | nilfs_copy_buffer(nbh, obh); |
| 285 | nilfs_btnode_mark_dirty(nbh); |
| 286 | |
| 287 | nbh->b_blocknr = newkey; |
| 288 | ctxt->bh = nbh; |
| 289 | nilfs_btnode_delete(obh); /* will decrement bh->b_count */ |
| 290 | } |
| 291 | } |
| 292 | |
| 293 | /** |
| 294 | * nilfs_btnode_abort_change_key |
| 295 | * abort the change_key operation prepared by prepare_change_key(). |
| 296 | */ |
| 297 | void nilfs_btnode_abort_change_key(struct address_space *btnc, |
| 298 | struct nilfs_btnode_chkey_ctxt *ctxt) |
| 299 | { |
| 300 | struct buffer_head *nbh = ctxt->newbh; |
| 301 | __u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey; |
| 302 | |
| 303 | if (oldkey == newkey) |
| 304 | return; |
| 305 | |
| 306 | if (nbh == NULL) { /* blocksize == pagesize */ |
| 307 | spin_lock_irq(&btnc->tree_lock); |
| 308 | radix_tree_delete(&btnc->page_tree, newkey); |
| 309 | spin_unlock_irq(&btnc->tree_lock); |
| 310 | unlock_page(ctxt->bh->b_page); |
| 311 | } else |
| 312 | brelse(nbh); |
| 313 | } |