Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 1 | /* -*- mode: c; c-basic-offset: 8; -*- |
| 2 | * vim: noexpandtab sw=8 ts=8 sts=0: |
| 3 | * |
| 4 | * uptodate.c |
| 5 | * |
| 6 | * Tracking the up-to-date-ness of a local buffer_head with respect to |
| 7 | * the cluster. |
| 8 | * |
| 9 | * Copyright (C) 2002, 2004, 2005 Oracle. All rights reserved. |
| 10 | * |
| 11 | * This program is free software; you can redistribute it and/or |
| 12 | * modify it under the terms of the GNU General Public |
| 13 | * License as published by the Free Software Foundation; either |
| 14 | * version 2 of the License, or (at your option) any later version. |
| 15 | * |
| 16 | * This program is distributed in the hope that it will be useful, |
| 17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 19 | * General Public License for more details. |
| 20 | * |
| 21 | * You should have received a copy of the GNU General Public |
| 22 | * License along with this program; if not, write to the |
| 23 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| 24 | * Boston, MA 021110-1307, USA. |
| 25 | * |
| 26 | * Standard buffer head caching flags (uptodate, etc) are insufficient |
| 27 | * in a clustered environment - a buffer may be marked up to date on |
| 28 | * our local node but could have been modified by another cluster |
| 29 | * member. As a result an additional (and performant) caching scheme |
| 30 | * is required. A further requirement is that we consume as little |
| 31 | * memory as possible - we never pin buffer_head structures in order |
| 32 | * to cache them. |
| 33 | * |
| 34 | * We track the existence of up to date buffers on the inodes which |
| 35 | * are associated with them. Because we don't want to pin |
| 36 | * buffer_heads, this is only a (strong) hint and several other checks |
| 37 | * are made in the I/O path to ensure that we don't use a stale or |
| 38 | * invalid buffer without going to disk: |
| 39 | * - buffer_jbd is used liberally - if a bh is in the journal on |
| 40 | * this node then it *must* be up to date. |
| 41 | * - the standard buffer_uptodate() macro is used to detect buffers |
| 42 | * which may be invalid (even if we have an up to date tracking |
| 43 | * item for them) |
| 44 | * |
| 45 | * For a full understanding of how this code works together, one |
| 46 | * should read the callers in dlmglue.c, the I/O functions in |
| 47 | * buffer_head_io.c and ocfs2_journal_access in journal.c |
| 48 | */ |
| 49 | |
| 50 | #include <linux/fs.h> |
| 51 | #include <linux/types.h> |
| 52 | #include <linux/slab.h> |
| 53 | #include <linux/highmem.h> |
| 54 | #include <linux/buffer_head.h> |
| 55 | #include <linux/rbtree.h> |
| 56 | #include <linux/jbd.h> |
| 57 | |
| 58 | #define MLOG_MASK_PREFIX ML_UPTODATE |
| 59 | |
| 60 | #include <cluster/masklog.h> |
| 61 | |
| 62 | #include "ocfs2.h" |
| 63 | |
| 64 | #include "inode.h" |
| 65 | #include "uptodate.h" |
| 66 | |
| 67 | struct ocfs2_meta_cache_item { |
| 68 | struct rb_node c_node; |
| 69 | sector_t c_block; |
| 70 | }; |
| 71 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 72 | static struct kmem_cache *ocfs2_uptodate_cachep = NULL; |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 73 | |
| 74 | void ocfs2_metadata_cache_init(struct inode *inode) |
| 75 | { |
| 76 | struct ocfs2_inode_info *oi = OCFS2_I(inode); |
| 77 | struct ocfs2_caching_info *ci = &oi->ip_metadata_cache; |
| 78 | |
| 79 | oi->ip_flags |= OCFS2_INODE_CACHE_INLINE; |
| 80 | ci->ci_num_cached = 0; |
| 81 | } |
| 82 | |
| 83 | /* No lock taken here as 'root' is not expected to be visible to other |
| 84 | * processes. */ |
| 85 | static unsigned int ocfs2_purge_copied_metadata_tree(struct rb_root *root) |
| 86 | { |
| 87 | unsigned int purged = 0; |
| 88 | struct rb_node *node; |
| 89 | struct ocfs2_meta_cache_item *item; |
| 90 | |
| 91 | while ((node = rb_last(root)) != NULL) { |
| 92 | item = rb_entry(node, struct ocfs2_meta_cache_item, c_node); |
| 93 | |
| 94 | mlog(0, "Purge item %llu\n", |
| 95 | (unsigned long long) item->c_block); |
| 96 | |
| 97 | rb_erase(&item->c_node, root); |
| 98 | kmem_cache_free(ocfs2_uptodate_cachep, item); |
| 99 | |
| 100 | purged++; |
| 101 | } |
| 102 | return purged; |
| 103 | } |
| 104 | |
| 105 | /* Called from locking and called from ocfs2_clear_inode. Dump the |
| 106 | * cache for a given inode. |
| 107 | * |
| 108 | * This function is a few more lines longer than necessary due to some |
| 109 | * accounting done here, but I think it's worth tracking down those |
| 110 | * bugs sooner -- Mark */ |
| 111 | void ocfs2_metadata_cache_purge(struct inode *inode) |
| 112 | { |
| 113 | struct ocfs2_inode_info *oi = OCFS2_I(inode); |
| 114 | unsigned int tree, to_purge, purged; |
| 115 | struct ocfs2_caching_info *ci = &oi->ip_metadata_cache; |
| 116 | struct rb_root root = RB_ROOT; |
| 117 | |
| 118 | spin_lock(&oi->ip_lock); |
| 119 | tree = !(oi->ip_flags & OCFS2_INODE_CACHE_INLINE); |
| 120 | to_purge = ci->ci_num_cached; |
| 121 | |
Mark Fasheh | b069705 | 2006-03-03 10:24:33 -0800 | [diff] [blame] | 122 | mlog(0, "Purge %u %s items from Inode %llu\n", to_purge, |
| 123 | tree ? "array" : "tree", (unsigned long long)oi->ip_blkno); |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 124 | |
| 125 | /* If we're a tree, save off the root so that we can safely |
| 126 | * initialize the cache. We do the work to free tree members |
| 127 | * without the spinlock. */ |
| 128 | if (tree) |
| 129 | root = ci->ci_cache.ci_tree; |
| 130 | |
| 131 | ocfs2_metadata_cache_init(inode); |
| 132 | spin_unlock(&oi->ip_lock); |
| 133 | |
| 134 | purged = ocfs2_purge_copied_metadata_tree(&root); |
| 135 | /* If possible, track the number wiped so that we can more |
| 136 | * easily detect counting errors. Unfortunately, this is only |
| 137 | * meaningful for trees. */ |
| 138 | if (tree && purged != to_purge) |
Mark Fasheh | b069705 | 2006-03-03 10:24:33 -0800 | [diff] [blame] | 139 | mlog(ML_ERROR, "Inode %llu, count = %u, purged = %u\n", |
| 140 | (unsigned long long)oi->ip_blkno, to_purge, purged); |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 141 | } |
| 142 | |
| 143 | /* Returns the index in the cache array, -1 if not found. |
| 144 | * Requires ip_lock. */ |
| 145 | static int ocfs2_search_cache_array(struct ocfs2_caching_info *ci, |
| 146 | sector_t item) |
| 147 | { |
| 148 | int i; |
| 149 | |
| 150 | for (i = 0; i < ci->ci_num_cached; i++) { |
| 151 | if (item == ci->ci_cache.ci_array[i]) |
| 152 | return i; |
| 153 | } |
| 154 | |
| 155 | return -1; |
| 156 | } |
| 157 | |
| 158 | /* Returns the cache item if found, otherwise NULL. |
| 159 | * Requires ip_lock. */ |
| 160 | static struct ocfs2_meta_cache_item * |
| 161 | ocfs2_search_cache_tree(struct ocfs2_caching_info *ci, |
| 162 | sector_t block) |
| 163 | { |
| 164 | struct rb_node * n = ci->ci_cache.ci_tree.rb_node; |
| 165 | struct ocfs2_meta_cache_item *item = NULL; |
| 166 | |
| 167 | while (n) { |
| 168 | item = rb_entry(n, struct ocfs2_meta_cache_item, c_node); |
| 169 | |
| 170 | if (block < item->c_block) |
| 171 | n = n->rb_left; |
| 172 | else if (block > item->c_block) |
| 173 | n = n->rb_right; |
| 174 | else |
| 175 | return item; |
| 176 | } |
| 177 | |
| 178 | return NULL; |
| 179 | } |
| 180 | |
| 181 | static int ocfs2_buffer_cached(struct ocfs2_inode_info *oi, |
| 182 | struct buffer_head *bh) |
| 183 | { |
| 184 | int index = -1; |
| 185 | struct ocfs2_meta_cache_item *item = NULL; |
| 186 | |
| 187 | spin_lock(&oi->ip_lock); |
| 188 | |
Mark Fasheh | b069705 | 2006-03-03 10:24:33 -0800 | [diff] [blame] | 189 | mlog(0, "Inode %llu, query block %llu (inline = %u)\n", |
| 190 | (unsigned long long)oi->ip_blkno, |
| 191 | (unsigned long long) bh->b_blocknr, |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 192 | !!(oi->ip_flags & OCFS2_INODE_CACHE_INLINE)); |
| 193 | |
| 194 | if (oi->ip_flags & OCFS2_INODE_CACHE_INLINE) |
| 195 | index = ocfs2_search_cache_array(&oi->ip_metadata_cache, |
| 196 | bh->b_blocknr); |
| 197 | else |
| 198 | item = ocfs2_search_cache_tree(&oi->ip_metadata_cache, |
| 199 | bh->b_blocknr); |
| 200 | |
| 201 | spin_unlock(&oi->ip_lock); |
| 202 | |
| 203 | mlog(0, "index = %d, item = %p\n", index, item); |
| 204 | |
| 205 | return (index != -1) || (item != NULL); |
| 206 | } |
| 207 | |
| 208 | /* Warning: even if it returns true, this does *not* guarantee that |
Mark Fasheh | aa95887 | 2006-04-21 13:49:02 -0700 | [diff] [blame] | 209 | * the block is stored in our inode metadata cache. |
| 210 | * |
| 211 | * This can be called under lock_buffer() |
| 212 | */ |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 213 | int ocfs2_buffer_uptodate(struct inode *inode, |
| 214 | struct buffer_head *bh) |
| 215 | { |
| 216 | /* Doesn't matter if the bh is in our cache or not -- if it's |
| 217 | * not marked uptodate then we know it can't have correct |
| 218 | * data. */ |
| 219 | if (!buffer_uptodate(bh)) |
| 220 | return 0; |
| 221 | |
| 222 | /* OCFS2 does not allow multiple nodes to be changing the same |
| 223 | * block at the same time. */ |
| 224 | if (buffer_jbd(bh)) |
| 225 | return 1; |
| 226 | |
| 227 | /* Ok, locally the buffer is marked as up to date, now search |
| 228 | * our cache to see if we can trust that. */ |
| 229 | return ocfs2_buffer_cached(OCFS2_I(inode), bh); |
| 230 | } |
| 231 | |
Mark Fasheh | aa95887 | 2006-04-21 13:49:02 -0700 | [diff] [blame] | 232 | /* |
| 233 | * Determine whether a buffer is currently out on a read-ahead request. |
| 234 | * ip_io_sem should be held to serialize submitters with the logic here. |
| 235 | */ |
| 236 | int ocfs2_buffer_read_ahead(struct inode *inode, |
| 237 | struct buffer_head *bh) |
| 238 | { |
| 239 | return buffer_locked(bh) && ocfs2_buffer_cached(OCFS2_I(inode), bh); |
| 240 | } |
| 241 | |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 242 | /* Requires ip_lock */ |
| 243 | static void ocfs2_append_cache_array(struct ocfs2_caching_info *ci, |
| 244 | sector_t block) |
| 245 | { |
| 246 | BUG_ON(ci->ci_num_cached >= OCFS2_INODE_MAX_CACHE_ARRAY); |
| 247 | |
| 248 | mlog(0, "block %llu takes position %u\n", (unsigned long long) block, |
| 249 | ci->ci_num_cached); |
| 250 | |
| 251 | ci->ci_cache.ci_array[ci->ci_num_cached] = block; |
| 252 | ci->ci_num_cached++; |
| 253 | } |
| 254 | |
| 255 | /* By now the caller should have checked that the item does *not* |
| 256 | * exist in the tree. |
| 257 | * Requires ip_lock. */ |
| 258 | static void __ocfs2_insert_cache_tree(struct ocfs2_caching_info *ci, |
| 259 | struct ocfs2_meta_cache_item *new) |
| 260 | { |
| 261 | sector_t block = new->c_block; |
| 262 | struct rb_node *parent = NULL; |
| 263 | struct rb_node **p = &ci->ci_cache.ci_tree.rb_node; |
| 264 | struct ocfs2_meta_cache_item *tmp; |
| 265 | |
| 266 | mlog(0, "Insert block %llu num = %u\n", (unsigned long long) block, |
| 267 | ci->ci_num_cached); |
| 268 | |
| 269 | while(*p) { |
| 270 | parent = *p; |
| 271 | |
| 272 | tmp = rb_entry(parent, struct ocfs2_meta_cache_item, c_node); |
| 273 | |
| 274 | if (block < tmp->c_block) |
| 275 | p = &(*p)->rb_left; |
| 276 | else if (block > tmp->c_block) |
| 277 | p = &(*p)->rb_right; |
| 278 | else { |
| 279 | /* This should never happen! */ |
| 280 | mlog(ML_ERROR, "Duplicate block %llu cached!\n", |
| 281 | (unsigned long long) block); |
| 282 | BUG(); |
| 283 | } |
| 284 | } |
| 285 | |
| 286 | rb_link_node(&new->c_node, parent, p); |
| 287 | rb_insert_color(&new->c_node, &ci->ci_cache.ci_tree); |
| 288 | ci->ci_num_cached++; |
| 289 | } |
| 290 | |
| 291 | static inline int ocfs2_insert_can_use_array(struct ocfs2_inode_info *oi, |
| 292 | struct ocfs2_caching_info *ci) |
| 293 | { |
| 294 | assert_spin_locked(&oi->ip_lock); |
| 295 | |
| 296 | return (oi->ip_flags & OCFS2_INODE_CACHE_INLINE) && |
| 297 | (ci->ci_num_cached < OCFS2_INODE_MAX_CACHE_ARRAY); |
| 298 | } |
| 299 | |
| 300 | /* tree should be exactly OCFS2_INODE_MAX_CACHE_ARRAY wide. NULL the |
| 301 | * pointers in tree after we use them - this allows caller to detect |
| 302 | * when to free in case of error. */ |
| 303 | static void ocfs2_expand_cache(struct ocfs2_inode_info *oi, |
| 304 | struct ocfs2_meta_cache_item **tree) |
| 305 | { |
| 306 | int i; |
| 307 | struct ocfs2_caching_info *ci = &oi->ip_metadata_cache; |
| 308 | |
| 309 | mlog_bug_on_msg(ci->ci_num_cached != OCFS2_INODE_MAX_CACHE_ARRAY, |
Mark Fasheh | b069705 | 2006-03-03 10:24:33 -0800 | [diff] [blame] | 310 | "Inode %llu, num cached = %u, should be %u\n", |
| 311 | (unsigned long long)oi->ip_blkno, ci->ci_num_cached, |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 312 | OCFS2_INODE_MAX_CACHE_ARRAY); |
| 313 | mlog_bug_on_msg(!(oi->ip_flags & OCFS2_INODE_CACHE_INLINE), |
Mark Fasheh | b069705 | 2006-03-03 10:24:33 -0800 | [diff] [blame] | 314 | "Inode %llu not marked as inline anymore!\n", |
| 315 | (unsigned long long)oi->ip_blkno); |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 316 | assert_spin_locked(&oi->ip_lock); |
| 317 | |
| 318 | /* Be careful to initialize the tree members *first* because |
| 319 | * once the ci_tree is used, the array is junk... */ |
| 320 | for(i = 0; i < OCFS2_INODE_MAX_CACHE_ARRAY; i++) |
| 321 | tree[i]->c_block = ci->ci_cache.ci_array[i]; |
| 322 | |
| 323 | oi->ip_flags &= ~OCFS2_INODE_CACHE_INLINE; |
| 324 | ci->ci_cache.ci_tree = RB_ROOT; |
| 325 | /* this will be set again by __ocfs2_insert_cache_tree */ |
| 326 | ci->ci_num_cached = 0; |
| 327 | |
| 328 | for(i = 0; i < OCFS2_INODE_MAX_CACHE_ARRAY; i++) { |
| 329 | __ocfs2_insert_cache_tree(ci, tree[i]); |
| 330 | tree[i] = NULL; |
| 331 | } |
| 332 | |
Mark Fasheh | b069705 | 2006-03-03 10:24:33 -0800 | [diff] [blame] | 333 | mlog(0, "Expanded %llu to a tree cache: flags 0x%x, num = %u\n", |
| 334 | (unsigned long long)oi->ip_blkno, oi->ip_flags, ci->ci_num_cached); |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 335 | } |
| 336 | |
| 337 | /* Slow path function - memory allocation is necessary. See the |
| 338 | * comment above ocfs2_set_buffer_uptodate for more information. */ |
| 339 | static void __ocfs2_set_buffer_uptodate(struct ocfs2_inode_info *oi, |
| 340 | sector_t block, |
| 341 | int expand_tree) |
| 342 | { |
| 343 | int i; |
| 344 | struct ocfs2_caching_info *ci = &oi->ip_metadata_cache; |
| 345 | struct ocfs2_meta_cache_item *new = NULL; |
| 346 | struct ocfs2_meta_cache_item *tree[OCFS2_INODE_MAX_CACHE_ARRAY] = |
| 347 | { NULL, }; |
| 348 | |
Mark Fasheh | b069705 | 2006-03-03 10:24:33 -0800 | [diff] [blame] | 349 | mlog(0, "Inode %llu, block %llu, expand = %d\n", |
| 350 | (unsigned long long)oi->ip_blkno, |
| 351 | (unsigned long long)block, expand_tree); |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 352 | |
Sunil Mushran | afae00ab | 2006-04-12 14:37:00 -0700 | [diff] [blame] | 353 | new = kmem_cache_alloc(ocfs2_uptodate_cachep, GFP_NOFS); |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 354 | if (!new) { |
| 355 | mlog_errno(-ENOMEM); |
| 356 | return; |
| 357 | } |
| 358 | new->c_block = block; |
| 359 | |
| 360 | if (expand_tree) { |
| 361 | /* Do *not* allocate an array here - the removal code |
| 362 | * has no way of tracking that. */ |
| 363 | for(i = 0; i < OCFS2_INODE_MAX_CACHE_ARRAY; i++) { |
| 364 | tree[i] = kmem_cache_alloc(ocfs2_uptodate_cachep, |
Sunil Mushran | afae00ab | 2006-04-12 14:37:00 -0700 | [diff] [blame] | 365 | GFP_NOFS); |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 366 | if (!tree[i]) { |
| 367 | mlog_errno(-ENOMEM); |
| 368 | goto out_free; |
| 369 | } |
| 370 | |
| 371 | /* These are initialized in ocfs2_expand_cache! */ |
| 372 | } |
| 373 | } |
| 374 | |
| 375 | spin_lock(&oi->ip_lock); |
| 376 | if (ocfs2_insert_can_use_array(oi, ci)) { |
| 377 | mlog(0, "Someone cleared the tree underneath us\n"); |
| 378 | /* Ok, items were removed from the cache in between |
| 379 | * locks. Detect this and revert back to the fast path */ |
| 380 | ocfs2_append_cache_array(ci, block); |
| 381 | spin_unlock(&oi->ip_lock); |
| 382 | goto out_free; |
| 383 | } |
| 384 | |
| 385 | if (expand_tree) |
| 386 | ocfs2_expand_cache(oi, tree); |
| 387 | |
| 388 | __ocfs2_insert_cache_tree(ci, new); |
| 389 | spin_unlock(&oi->ip_lock); |
| 390 | |
| 391 | new = NULL; |
| 392 | out_free: |
| 393 | if (new) |
| 394 | kmem_cache_free(ocfs2_uptodate_cachep, new); |
| 395 | |
| 396 | /* If these were used, then ocfs2_expand_cache re-set them to |
| 397 | * NULL for us. */ |
| 398 | if (tree[0]) { |
| 399 | for(i = 0; i < OCFS2_INODE_MAX_CACHE_ARRAY; i++) |
| 400 | if (tree[i]) |
| 401 | kmem_cache_free(ocfs2_uptodate_cachep, |
| 402 | tree[i]); |
| 403 | } |
| 404 | } |
| 405 | |
Mark Fasheh | 251b6ec | 2006-01-10 15:41:43 -0800 | [diff] [blame] | 406 | /* Item insertion is guarded by ip_io_mutex, so the insertion path takes |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 407 | * advantage of this by not rechecking for a duplicate insert during |
| 408 | * the slow case. Additionally, if the cache needs to be bumped up to |
| 409 | * a tree, the code will not recheck after acquiring the lock -- |
| 410 | * multiple paths cannot be expanding to a tree at the same time. |
| 411 | * |
| 412 | * The slow path takes into account that items can be removed |
| 413 | * (including the whole tree wiped and reset) when this process it out |
| 414 | * allocating memory. In those cases, it reverts back to the fast |
| 415 | * path. |
| 416 | * |
| 417 | * Note that this function may actually fail to insert the block if |
| 418 | * memory cannot be allocated. This is not fatal however (but may |
Mark Fasheh | aa95887 | 2006-04-21 13:49:02 -0700 | [diff] [blame] | 419 | * result in a performance penalty) |
| 420 | * |
| 421 | * Readahead buffers can be passed in here before the I/O request is |
| 422 | * completed. |
| 423 | */ |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 424 | void ocfs2_set_buffer_uptodate(struct inode *inode, |
| 425 | struct buffer_head *bh) |
| 426 | { |
| 427 | int expand; |
| 428 | struct ocfs2_inode_info *oi = OCFS2_I(inode); |
| 429 | struct ocfs2_caching_info *ci = &oi->ip_metadata_cache; |
| 430 | |
| 431 | /* The block may very well exist in our cache already, so avoid |
| 432 | * doing any more work in that case. */ |
| 433 | if (ocfs2_buffer_cached(oi, bh)) |
| 434 | return; |
| 435 | |
Mark Fasheh | b069705 | 2006-03-03 10:24:33 -0800 | [diff] [blame] | 436 | mlog(0, "Inode %llu, inserting block %llu\n", |
| 437 | (unsigned long long)oi->ip_blkno, |
| 438 | (unsigned long long)bh->b_blocknr); |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 439 | |
| 440 | /* No need to recheck under spinlock - insertion is guarded by |
Mark Fasheh | 251b6ec | 2006-01-10 15:41:43 -0800 | [diff] [blame] | 441 | * ip_io_mutex */ |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 442 | spin_lock(&oi->ip_lock); |
| 443 | if (ocfs2_insert_can_use_array(oi, ci)) { |
| 444 | /* Fast case - it's an array and there's a free |
| 445 | * spot. */ |
| 446 | ocfs2_append_cache_array(ci, bh->b_blocknr); |
| 447 | spin_unlock(&oi->ip_lock); |
| 448 | return; |
| 449 | } |
| 450 | |
| 451 | expand = 0; |
| 452 | if (oi->ip_flags & OCFS2_INODE_CACHE_INLINE) { |
| 453 | /* We need to bump things up to a tree. */ |
| 454 | expand = 1; |
| 455 | } |
| 456 | spin_unlock(&oi->ip_lock); |
| 457 | |
| 458 | __ocfs2_set_buffer_uptodate(oi, bh->b_blocknr, expand); |
| 459 | } |
| 460 | |
| 461 | /* Called against a newly allocated buffer. Most likely nobody should |
| 462 | * be able to read this sort of metadata while it's still being |
Mark Fasheh | 251b6ec | 2006-01-10 15:41:43 -0800 | [diff] [blame] | 463 | * allocated, but this is careful to take ip_io_mutex anyway. */ |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 464 | void ocfs2_set_new_buffer_uptodate(struct inode *inode, |
| 465 | struct buffer_head *bh) |
| 466 | { |
| 467 | struct ocfs2_inode_info *oi = OCFS2_I(inode); |
| 468 | |
| 469 | /* This should definitely *not* exist in our cache */ |
| 470 | BUG_ON(ocfs2_buffer_cached(oi, bh)); |
| 471 | |
| 472 | set_buffer_uptodate(bh); |
| 473 | |
Mark Fasheh | 251b6ec | 2006-01-10 15:41:43 -0800 | [diff] [blame] | 474 | mutex_lock(&oi->ip_io_mutex); |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 475 | ocfs2_set_buffer_uptodate(inode, bh); |
Mark Fasheh | 251b6ec | 2006-01-10 15:41:43 -0800 | [diff] [blame] | 476 | mutex_unlock(&oi->ip_io_mutex); |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 477 | } |
| 478 | |
| 479 | /* Requires ip_lock. */ |
| 480 | static void ocfs2_remove_metadata_array(struct ocfs2_caching_info *ci, |
| 481 | int index) |
| 482 | { |
| 483 | sector_t *array = ci->ci_cache.ci_array; |
| 484 | int bytes; |
| 485 | |
| 486 | BUG_ON(index < 0 || index >= OCFS2_INODE_MAX_CACHE_ARRAY); |
| 487 | BUG_ON(index >= ci->ci_num_cached); |
| 488 | BUG_ON(!ci->ci_num_cached); |
| 489 | |
| 490 | mlog(0, "remove index %d (num_cached = %u\n", index, |
| 491 | ci->ci_num_cached); |
| 492 | |
| 493 | ci->ci_num_cached--; |
| 494 | |
| 495 | /* don't need to copy if the array is now empty, or if we |
| 496 | * removed at the tail */ |
| 497 | if (ci->ci_num_cached && index < ci->ci_num_cached) { |
| 498 | bytes = sizeof(sector_t) * (ci->ci_num_cached - index); |
| 499 | memmove(&array[index], &array[index + 1], bytes); |
| 500 | } |
| 501 | } |
| 502 | |
| 503 | /* Requires ip_lock. */ |
| 504 | static void ocfs2_remove_metadata_tree(struct ocfs2_caching_info *ci, |
| 505 | struct ocfs2_meta_cache_item *item) |
| 506 | { |
| 507 | mlog(0, "remove block %llu from tree\n", |
| 508 | (unsigned long long) item->c_block); |
| 509 | |
| 510 | rb_erase(&item->c_node, &ci->ci_cache.ci_tree); |
| 511 | ci->ci_num_cached--; |
| 512 | } |
| 513 | |
| 514 | /* Called when we remove a chunk of metadata from an inode. We don't |
| 515 | * bother reverting things to an inlined array in the case of a remove |
| 516 | * which moves us back under the limit. */ |
| 517 | void ocfs2_remove_from_cache(struct inode *inode, |
| 518 | struct buffer_head *bh) |
| 519 | { |
| 520 | int index; |
| 521 | sector_t block = bh->b_blocknr; |
| 522 | struct ocfs2_meta_cache_item *item = NULL; |
| 523 | struct ocfs2_inode_info *oi = OCFS2_I(inode); |
| 524 | struct ocfs2_caching_info *ci = &oi->ip_metadata_cache; |
| 525 | |
| 526 | spin_lock(&oi->ip_lock); |
Mark Fasheh | b069705 | 2006-03-03 10:24:33 -0800 | [diff] [blame] | 527 | mlog(0, "Inode %llu, remove %llu, items = %u, array = %u\n", |
| 528 | (unsigned long long)oi->ip_blkno, |
| 529 | (unsigned long long) block, ci->ci_num_cached, |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 530 | oi->ip_flags & OCFS2_INODE_CACHE_INLINE); |
| 531 | |
| 532 | if (oi->ip_flags & OCFS2_INODE_CACHE_INLINE) { |
| 533 | index = ocfs2_search_cache_array(ci, block); |
| 534 | if (index != -1) |
| 535 | ocfs2_remove_metadata_array(ci, index); |
| 536 | } else { |
| 537 | item = ocfs2_search_cache_tree(ci, block); |
| 538 | if (item) |
| 539 | ocfs2_remove_metadata_tree(ci, item); |
| 540 | } |
| 541 | spin_unlock(&oi->ip_lock); |
| 542 | |
| 543 | if (item) |
| 544 | kmem_cache_free(ocfs2_uptodate_cachep, item); |
| 545 | } |
| 546 | |
| 547 | int __init init_ocfs2_uptodate_cache(void) |
| 548 | { |
| 549 | ocfs2_uptodate_cachep = kmem_cache_create("ocfs2_uptodate", |
| 550 | sizeof(struct ocfs2_meta_cache_item), |
| 551 | 0, SLAB_HWCACHE_ALIGN, NULL, NULL); |
| 552 | if (!ocfs2_uptodate_cachep) |
| 553 | return -ENOMEM; |
| 554 | |
| 555 | mlog(0, "%u inlined cache items per inode.\n", |
| 556 | OCFS2_INODE_MAX_CACHE_ARRAY); |
| 557 | |
| 558 | return 0; |
| 559 | } |
| 560 | |
Adrian Bunk | 0c6c98f | 2006-01-07 20:07:02 +0100 | [diff] [blame] | 561 | void exit_ocfs2_uptodate_cache(void) |
Mark Fasheh | ccd979b | 2005-12-15 14:31:24 -0800 | [diff] [blame] | 562 | { |
| 563 | if (ocfs2_uptodate_cachep) |
| 564 | kmem_cache_destroy(ocfs2_uptodate_cachep); |
| 565 | } |