diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/ocfs2/uptodate.c')
| -rw-r--r-- | ANDROID_3.4.5/fs/ocfs2/uptodate.c | 638 |
1 files changed, 0 insertions, 638 deletions
diff --git a/ANDROID_3.4.5/fs/ocfs2/uptodate.c b/ANDROID_3.4.5/fs/ocfs2/uptodate.c deleted file mode 100644 index 52eaf33d..00000000 --- a/ANDROID_3.4.5/fs/ocfs2/uptodate.c +++ /dev/null @@ -1,638 +0,0 @@ -/* -*- mode: c; c-basic-offset: 8; -*- - * vim: noexpandtab sw=8 ts=8 sts=0: - * - * uptodate.c - * - * Tracking the up-to-date-ness of a local buffer_head with respect to - * the cluster. - * - * Copyright (C) 2002, 2004, 2005 Oracle. All rights reserved. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public - * License as published by the Free Software Foundation; either - * version 2 of the License, or (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public - * License along with this program; if not, write to the - * Free Software Foundation, Inc., 59 Temple Place - Suite 330, - * Boston, MA 021110-1307, USA. - * - * Standard buffer head caching flags (uptodate, etc) are insufficient - * in a clustered environment - a buffer may be marked up to date on - * our local node but could have been modified by another cluster - * member. As a result an additional (and performant) caching scheme - * is required. A further requirement is that we consume as little - * memory as possible - we never pin buffer_head structures in order - * to cache them. - * - * We track the existence of up to date buffers on the inodes which - * are associated with them. Because we don't want to pin - * buffer_heads, this is only a (strong) hint and several other checks - * are made in the I/O path to ensure that we don't use a stale or - * invalid buffer without going to disk: - * - buffer_jbd is used liberally - if a bh is in the journal on - * this node then it *must* be up to date. - * - the standard buffer_uptodate() macro is used to detect buffers - * which may be invalid (even if we have an up to date tracking - * item for them) - * - * For a full understanding of how this code works together, one - * should read the callers in dlmglue.c, the I/O functions in - * buffer_head_io.c and ocfs2_journal_access in journal.c - */ - -#include <linux/fs.h> -#include <linux/types.h> -#include <linux/slab.h> -#include <linux/highmem.h> -#include <linux/buffer_head.h> -#include <linux/rbtree.h> - -#include <cluster/masklog.h> - -#include "ocfs2.h" - -#include "inode.h" -#include "uptodate.h" -#include "ocfs2_trace.h" - -struct ocfs2_meta_cache_item { - struct rb_node c_node; - sector_t c_block; -}; - -static struct kmem_cache *ocfs2_uptodate_cachep = NULL; - -u64 ocfs2_metadata_cache_owner(struct ocfs2_caching_info *ci) -{ - BUG_ON(!ci || !ci->ci_ops); - - return ci->ci_ops->co_owner(ci); -} - -struct super_block *ocfs2_metadata_cache_get_super(struct ocfs2_caching_info *ci) -{ - BUG_ON(!ci || !ci->ci_ops); - - return ci->ci_ops->co_get_super(ci); -} - -static void ocfs2_metadata_cache_lock(struct ocfs2_caching_info *ci) -{ - BUG_ON(!ci || !ci->ci_ops); - - ci->ci_ops->co_cache_lock(ci); -} - -static void ocfs2_metadata_cache_unlock(struct ocfs2_caching_info *ci) -{ - BUG_ON(!ci || !ci->ci_ops); - - ci->ci_ops->co_cache_unlock(ci); -} - -void ocfs2_metadata_cache_io_lock(struct ocfs2_caching_info *ci) -{ - BUG_ON(!ci || !ci->ci_ops); - - ci->ci_ops->co_io_lock(ci); -} - -void ocfs2_metadata_cache_io_unlock(struct ocfs2_caching_info *ci) -{ - BUG_ON(!ci || !ci->ci_ops); - - ci->ci_ops->co_io_unlock(ci); -} - - -static void ocfs2_metadata_cache_reset(struct ocfs2_caching_info *ci, - int clear) -{ - ci->ci_flags |= OCFS2_CACHE_FL_INLINE; - ci->ci_num_cached = 0; - - if (clear) { - ci->ci_created_trans = 0; - ci->ci_last_trans = 0; - } -} - -void ocfs2_metadata_cache_init(struct ocfs2_caching_info *ci, - const struct ocfs2_caching_operations *ops) -{ - BUG_ON(!ops); - - ci->ci_ops = ops; - ocfs2_metadata_cache_reset(ci, 1); -} - -void ocfs2_metadata_cache_exit(struct ocfs2_caching_info *ci) -{ - ocfs2_metadata_cache_purge(ci); - ocfs2_metadata_cache_reset(ci, 1); -} - - -/* No lock taken here as 'root' is not expected to be visible to other - * processes. */ -static unsigned int ocfs2_purge_copied_metadata_tree(struct rb_root *root) -{ - unsigned int purged = 0; - struct rb_node *node; - struct ocfs2_meta_cache_item *item; - - while ((node = rb_last(root)) != NULL) { - item = rb_entry(node, struct ocfs2_meta_cache_item, c_node); - - trace_ocfs2_purge_copied_metadata_tree( - (unsigned long long) item->c_block); - - rb_erase(&item->c_node, root); - kmem_cache_free(ocfs2_uptodate_cachep, item); - - purged++; - } - return purged; -} - -/* Called from locking and called from ocfs2_clear_inode. Dump the - * cache for a given inode. - * - * This function is a few more lines longer than necessary due to some - * accounting done here, but I think it's worth tracking down those - * bugs sooner -- Mark */ -void ocfs2_metadata_cache_purge(struct ocfs2_caching_info *ci) -{ - unsigned int tree, to_purge, purged; - struct rb_root root = RB_ROOT; - - BUG_ON(!ci || !ci->ci_ops); - - ocfs2_metadata_cache_lock(ci); - tree = !(ci->ci_flags & OCFS2_CACHE_FL_INLINE); - to_purge = ci->ci_num_cached; - - trace_ocfs2_metadata_cache_purge( - (unsigned long long)ocfs2_metadata_cache_owner(ci), - to_purge, tree); - - /* If we're a tree, save off the root so that we can safely - * initialize the cache. We do the work to free tree members - * without the spinlock. */ - if (tree) - root = ci->ci_cache.ci_tree; - - ocfs2_metadata_cache_reset(ci, 0); - ocfs2_metadata_cache_unlock(ci); - - purged = ocfs2_purge_copied_metadata_tree(&root); - /* If possible, track the number wiped so that we can more - * easily detect counting errors. Unfortunately, this is only - * meaningful for trees. */ - if (tree && purged != to_purge) - mlog(ML_ERROR, "Owner %llu, count = %u, purged = %u\n", - (unsigned long long)ocfs2_metadata_cache_owner(ci), - to_purge, purged); -} - -/* Returns the index in the cache array, -1 if not found. - * Requires ip_lock. */ -static int ocfs2_search_cache_array(struct ocfs2_caching_info *ci, - sector_t item) -{ - int i; - - for (i = 0; i < ci->ci_num_cached; i++) { - if (item == ci->ci_cache.ci_array[i]) - return i; - } - - return -1; -} - -/* Returns the cache item if found, otherwise NULL. - * Requires ip_lock. */ -static struct ocfs2_meta_cache_item * -ocfs2_search_cache_tree(struct ocfs2_caching_info *ci, - sector_t block) -{ - struct rb_node * n = ci->ci_cache.ci_tree.rb_node; - struct ocfs2_meta_cache_item *item = NULL; - - while (n) { - item = rb_entry(n, struct ocfs2_meta_cache_item, c_node); - - if (block < item->c_block) - n = n->rb_left; - else if (block > item->c_block) - n = n->rb_right; - else - return item; - } - - return NULL; -} - -static int ocfs2_buffer_cached(struct ocfs2_caching_info *ci, - struct buffer_head *bh) -{ - int index = -1; - struct ocfs2_meta_cache_item *item = NULL; - - ocfs2_metadata_cache_lock(ci); - - trace_ocfs2_buffer_cached_begin( - (unsigned long long)ocfs2_metadata_cache_owner(ci), - (unsigned long long) bh->b_blocknr, - !!(ci->ci_flags & OCFS2_CACHE_FL_INLINE)); - - if (ci->ci_flags & OCFS2_CACHE_FL_INLINE) - index = ocfs2_search_cache_array(ci, bh->b_blocknr); - else - item = ocfs2_search_cache_tree(ci, bh->b_blocknr); - - ocfs2_metadata_cache_unlock(ci); - - trace_ocfs2_buffer_cached_end(index, item); - - return (index != -1) || (item != NULL); -} - -/* Warning: even if it returns true, this does *not* guarantee that - * the block is stored in our inode metadata cache. - * - * This can be called under lock_buffer() - */ -int ocfs2_buffer_uptodate(struct ocfs2_caching_info *ci, - struct buffer_head *bh) -{ - /* Doesn't matter if the bh is in our cache or not -- if it's - * not marked uptodate then we know it can't have correct - * data. */ - if (!buffer_uptodate(bh)) - return 0; - - /* OCFS2 does not allow multiple nodes to be changing the same - * block at the same time. */ - if (buffer_jbd(bh)) - return 1; - - /* Ok, locally the buffer is marked as up to date, now search - * our cache to see if we can trust that. */ - return ocfs2_buffer_cached(ci, bh); -} - -/* - * Determine whether a buffer is currently out on a read-ahead request. - * ci_io_sem should be held to serialize submitters with the logic here. - */ -int ocfs2_buffer_read_ahead(struct ocfs2_caching_info *ci, - struct buffer_head *bh) -{ - return buffer_locked(bh) && ocfs2_buffer_cached(ci, bh); -} - -/* Requires ip_lock */ -static void ocfs2_append_cache_array(struct ocfs2_caching_info *ci, - sector_t block) -{ - BUG_ON(ci->ci_num_cached >= OCFS2_CACHE_INFO_MAX_ARRAY); - - trace_ocfs2_append_cache_array( - (unsigned long long)ocfs2_metadata_cache_owner(ci), - (unsigned long long)block, ci->ci_num_cached); - - ci->ci_cache.ci_array[ci->ci_num_cached] = block; - ci->ci_num_cached++; -} - -/* By now the caller should have checked that the item does *not* - * exist in the tree. - * Requires ip_lock. */ -static void __ocfs2_insert_cache_tree(struct ocfs2_caching_info *ci, - struct ocfs2_meta_cache_item *new) -{ - sector_t block = new->c_block; - struct rb_node *parent = NULL; - struct rb_node **p = &ci->ci_cache.ci_tree.rb_node; - struct ocfs2_meta_cache_item *tmp; - - trace_ocfs2_insert_cache_tree( - (unsigned long long)ocfs2_metadata_cache_owner(ci), - (unsigned long long)block, ci->ci_num_cached); - - while(*p) { - parent = *p; - - tmp = rb_entry(parent, struct ocfs2_meta_cache_item, c_node); - - if (block < tmp->c_block) - p = &(*p)->rb_left; - else if (block > tmp->c_block) - p = &(*p)->rb_right; - else { - /* This should never happen! */ - mlog(ML_ERROR, "Duplicate block %llu cached!\n", - (unsigned long long) block); - BUG(); - } - } - - rb_link_node(&new->c_node, parent, p); - rb_insert_color(&new->c_node, &ci->ci_cache.ci_tree); - ci->ci_num_cached++; -} - -/* co_cache_lock() must be held */ -static inline int ocfs2_insert_can_use_array(struct ocfs2_caching_info *ci) -{ - return (ci->ci_flags & OCFS2_CACHE_FL_INLINE) && - (ci->ci_num_cached < OCFS2_CACHE_INFO_MAX_ARRAY); -} - -/* tree should be exactly OCFS2_CACHE_INFO_MAX_ARRAY wide. NULL the - * pointers in tree after we use them - this allows caller to detect - * when to free in case of error. - * - * The co_cache_lock() must be held. */ -static void ocfs2_expand_cache(struct ocfs2_caching_info *ci, - struct ocfs2_meta_cache_item **tree) -{ - int i; - - mlog_bug_on_msg(ci->ci_num_cached != OCFS2_CACHE_INFO_MAX_ARRAY, - "Owner %llu, num cached = %u, should be %u\n", - (unsigned long long)ocfs2_metadata_cache_owner(ci), - ci->ci_num_cached, OCFS2_CACHE_INFO_MAX_ARRAY); - mlog_bug_on_msg(!(ci->ci_flags & OCFS2_CACHE_FL_INLINE), - "Owner %llu not marked as inline anymore!\n", - (unsigned long long)ocfs2_metadata_cache_owner(ci)); - - /* Be careful to initialize the tree members *first* because - * once the ci_tree is used, the array is junk... */ - for (i = 0; i < OCFS2_CACHE_INFO_MAX_ARRAY; i++) - tree[i]->c_block = ci->ci_cache.ci_array[i]; - - ci->ci_flags &= ~OCFS2_CACHE_FL_INLINE; - ci->ci_cache.ci_tree = RB_ROOT; - /* this will be set again by __ocfs2_insert_cache_tree */ - ci->ci_num_cached = 0; - - for (i = 0; i < OCFS2_CACHE_INFO_MAX_ARRAY; i++) { - __ocfs2_insert_cache_tree(ci, tree[i]); - tree[i] = NULL; - } - - trace_ocfs2_expand_cache( - (unsigned long long)ocfs2_metadata_cache_owner(ci), - ci->ci_flags, ci->ci_num_cached); -} - -/* Slow path function - memory allocation is necessary. See the - * comment above ocfs2_set_buffer_uptodate for more information. */ -static void __ocfs2_set_buffer_uptodate(struct ocfs2_caching_info *ci, - sector_t block, - int expand_tree) -{ - int i; - struct ocfs2_meta_cache_item *new = NULL; - struct ocfs2_meta_cache_item *tree[OCFS2_CACHE_INFO_MAX_ARRAY] = - { NULL, }; - - trace_ocfs2_set_buffer_uptodate( - (unsigned long long)ocfs2_metadata_cache_owner(ci), - (unsigned long long)block, expand_tree); - - new = kmem_cache_alloc(ocfs2_uptodate_cachep, GFP_NOFS); - if (!new) { - mlog_errno(-ENOMEM); - return; - } - new->c_block = block; - - if (expand_tree) { - /* Do *not* allocate an array here - the removal code - * has no way of tracking that. */ - for (i = 0; i < OCFS2_CACHE_INFO_MAX_ARRAY; i++) { - tree[i] = kmem_cache_alloc(ocfs2_uptodate_cachep, - GFP_NOFS); - if (!tree[i]) { - mlog_errno(-ENOMEM); - goto out_free; - } - - /* These are initialized in ocfs2_expand_cache! */ - } - } - - ocfs2_metadata_cache_lock(ci); - if (ocfs2_insert_can_use_array(ci)) { - /* Ok, items were removed from the cache in between - * locks. Detect this and revert back to the fast path */ - ocfs2_append_cache_array(ci, block); - ocfs2_metadata_cache_unlock(ci); - goto out_free; - } - - if (expand_tree) - ocfs2_expand_cache(ci, tree); - - __ocfs2_insert_cache_tree(ci, new); - ocfs2_metadata_cache_unlock(ci); - - new = NULL; -out_free: - if (new) - kmem_cache_free(ocfs2_uptodate_cachep, new); - - /* If these were used, then ocfs2_expand_cache re-set them to - * NULL for us. */ - if (tree[0]) { - for (i = 0; i < OCFS2_CACHE_INFO_MAX_ARRAY; i++) - if (tree[i]) - kmem_cache_free(ocfs2_uptodate_cachep, - tree[i]); - } -} - -/* Item insertion is guarded by co_io_lock(), so the insertion path takes - * advantage of this by not rechecking for a duplicate insert during - * the slow case. Additionally, if the cache needs to be bumped up to - * a tree, the code will not recheck after acquiring the lock -- - * multiple paths cannot be expanding to a tree at the same time. - * - * The slow path takes into account that items can be removed - * (including the whole tree wiped and reset) when this process it out - * allocating memory. In those cases, it reverts back to the fast - * path. - * - * Note that this function may actually fail to insert the block if - * memory cannot be allocated. This is not fatal however (but may - * result in a performance penalty) - * - * Readahead buffers can be passed in here before the I/O request is - * completed. - */ -void ocfs2_set_buffer_uptodate(struct ocfs2_caching_info *ci, - struct buffer_head *bh) -{ - int expand; - - /* The block may very well exist in our cache already, so avoid - * doing any more work in that case. */ - if (ocfs2_buffer_cached(ci, bh)) - return; - - trace_ocfs2_set_buffer_uptodate_begin( - (unsigned long long)ocfs2_metadata_cache_owner(ci), - (unsigned long long)bh->b_blocknr); - - /* No need to recheck under spinlock - insertion is guarded by - * co_io_lock() */ - ocfs2_metadata_cache_lock(ci); - if (ocfs2_insert_can_use_array(ci)) { - /* Fast case - it's an array and there's a free - * spot. */ - ocfs2_append_cache_array(ci, bh->b_blocknr); - ocfs2_metadata_cache_unlock(ci); - return; - } - - expand = 0; - if (ci->ci_flags & OCFS2_CACHE_FL_INLINE) { - /* We need to bump things up to a tree. */ - expand = 1; - } - ocfs2_metadata_cache_unlock(ci); - - __ocfs2_set_buffer_uptodate(ci, bh->b_blocknr, expand); -} - -/* Called against a newly allocated buffer. Most likely nobody should - * be able to read this sort of metadata while it's still being - * allocated, but this is careful to take co_io_lock() anyway. */ -void ocfs2_set_new_buffer_uptodate(struct ocfs2_caching_info *ci, - struct buffer_head *bh) -{ - /* This should definitely *not* exist in our cache */ - BUG_ON(ocfs2_buffer_cached(ci, bh)); - - set_buffer_uptodate(bh); - - ocfs2_metadata_cache_io_lock(ci); - ocfs2_set_buffer_uptodate(ci, bh); - ocfs2_metadata_cache_io_unlock(ci); -} - -/* Requires ip_lock. */ -static void ocfs2_remove_metadata_array(struct ocfs2_caching_info *ci, - int index) -{ - sector_t *array = ci->ci_cache.ci_array; - int bytes; - - BUG_ON(index < 0 || index >= OCFS2_CACHE_INFO_MAX_ARRAY); - BUG_ON(index >= ci->ci_num_cached); - BUG_ON(!ci->ci_num_cached); - - trace_ocfs2_remove_metadata_array( - (unsigned long long)ocfs2_metadata_cache_owner(ci), - index, ci->ci_num_cached); - - ci->ci_num_cached--; - - /* don't need to copy if the array is now empty, or if we - * removed at the tail */ - if (ci->ci_num_cached && index < ci->ci_num_cached) { - bytes = sizeof(sector_t) * (ci->ci_num_cached - index); - memmove(&array[index], &array[index + 1], bytes); - } -} - -/* Requires ip_lock. */ -static void ocfs2_remove_metadata_tree(struct ocfs2_caching_info *ci, - struct ocfs2_meta_cache_item *item) -{ - trace_ocfs2_remove_metadata_tree( - (unsigned long long)ocfs2_metadata_cache_owner(ci), - (unsigned long long)item->c_block); - - rb_erase(&item->c_node, &ci->ci_cache.ci_tree); - ci->ci_num_cached--; -} - -static void ocfs2_remove_block_from_cache(struct ocfs2_caching_info *ci, - sector_t block) -{ - int index; - struct ocfs2_meta_cache_item *item = NULL; - - ocfs2_metadata_cache_lock(ci); - trace_ocfs2_remove_block_from_cache( - (unsigned long long)ocfs2_metadata_cache_owner(ci), - (unsigned long long) block, ci->ci_num_cached, - ci->ci_flags); - - if (ci->ci_flags & OCFS2_CACHE_FL_INLINE) { - index = ocfs2_search_cache_array(ci, block); - if (index != -1) - ocfs2_remove_metadata_array(ci, index); - } else { - item = ocfs2_search_cache_tree(ci, block); - if (item) - ocfs2_remove_metadata_tree(ci, item); - } - ocfs2_metadata_cache_unlock(ci); - - if (item) - kmem_cache_free(ocfs2_uptodate_cachep, item); -} - -/* - * Called when we remove a chunk of metadata from an inode. We don't - * bother reverting things to an inlined array in the case of a remove - * which moves us back under the limit. - */ -void ocfs2_remove_from_cache(struct ocfs2_caching_info *ci, - struct buffer_head *bh) -{ - sector_t block = bh->b_blocknr; - - ocfs2_remove_block_from_cache(ci, block); -} - -/* Called when we remove xattr clusters from an inode. */ -void ocfs2_remove_xattr_clusters_from_cache(struct ocfs2_caching_info *ci, - sector_t block, - u32 c_len) -{ - struct super_block *sb = ocfs2_metadata_cache_get_super(ci); - unsigned int i, b_len = ocfs2_clusters_to_blocks(sb, 1) * c_len; - - for (i = 0; i < b_len; i++, block++) - ocfs2_remove_block_from_cache(ci, block); -} - -int __init init_ocfs2_uptodate_cache(void) -{ - ocfs2_uptodate_cachep = kmem_cache_create("ocfs2_uptodate", - sizeof(struct ocfs2_meta_cache_item), - 0, SLAB_HWCACHE_ALIGN, NULL); - if (!ocfs2_uptodate_cachep) - return -ENOMEM; - - return 0; -} - -void exit_ocfs2_uptodate_cache(void) -{ - if (ocfs2_uptodate_cachep) - kmem_cache_destroy(ocfs2_uptodate_cachep); -} |