From 0414efae7989a2183fb2cc000ab285c4c2836a00 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 20 Apr 2011 10:20:14 +0800 Subject: [PATCH] Btrfs: Make the code for reading/writing free space cache generic Extract out block group specific code from lookup_free_space_inode(), create_free_space_inode(), load_free_space_cache() and btrfs_write_out_cache(), so the code can be used to read/write free ino cache. Signed-off-by: Li Zefan --- fs/btrfs/free-space-cache.c | 358 ++++++++++++++++++++---------------- 1 file changed, 204 insertions(+), 154 deletions(-) diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index 2ce89bfc8815..fcbdcef6ca28 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -33,9 +33,9 @@ static int link_free_space(struct btrfs_free_space_ctl *ctl, struct btrfs_free_space *info); -struct inode *lookup_free_space_inode(struct btrfs_root *root, - struct btrfs_block_group_cache - *block_group, struct btrfs_path *path) +static struct inode *__lookup_free_space_inode(struct btrfs_root *root, + struct btrfs_path *path, + u64 offset) { struct btrfs_key key; struct btrfs_key location; @@ -45,15 +45,8 @@ struct inode *lookup_free_space_inode(struct btrfs_root *root, struct inode *inode = NULL; int ret; - spin_lock(&block_group->lock); - if (block_group->inode) - inode = igrab(block_group->inode); - spin_unlock(&block_group->lock); - if (inode) - return inode; - key.objectid = BTRFS_FREE_SPACE_OBJECTID; - key.offset = block_group->key.objectid; + key.offset = offset; key.type = 0; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); @@ -83,6 +76,27 @@ struct inode *lookup_free_space_inode(struct btrfs_root *root, inode->i_mapping->flags &= ~__GFP_FS; + return inode; +} + +struct inode *lookup_free_space_inode(struct btrfs_root *root, + struct btrfs_block_group_cache + *block_group, struct btrfs_path *path) +{ + struct inode *inode = NULL; + + spin_lock(&block_group->lock); + if (block_group->inode) + inode = igrab(block_group->inode); + spin_unlock(&block_group->lock); + if (inode) + return inode; + + inode = __lookup_free_space_inode(root, path, + block_group->key.objectid); + if (IS_ERR(inode)) + return inode; + spin_lock(&block_group->lock); if (!root->fs_info->closing) { block_group->inode = igrab(inode); @@ -93,24 +107,18 @@ struct inode *lookup_free_space_inode(struct btrfs_root *root, return inode; } -int create_free_space_inode(struct btrfs_root *root, - struct btrfs_trans_handle *trans, - struct btrfs_block_group_cache *block_group, - struct btrfs_path *path) +int __create_free_space_inode(struct btrfs_root *root, + struct btrfs_trans_handle *trans, + struct btrfs_path *path, u64 ino, u64 offset) { struct btrfs_key key; struct btrfs_disk_key disk_key; struct btrfs_free_space_header *header; struct btrfs_inode_item *inode_item; struct extent_buffer *leaf; - u64 objectid; int ret; - ret = btrfs_find_free_objectid(root, &objectid); - if (ret < 0) - return ret; - - ret = btrfs_insert_empty_inode(trans, root, path, objectid); + ret = btrfs_insert_empty_inode(trans, root, path, ino); if (ret) return ret; @@ -130,13 +138,12 @@ int create_free_space_inode(struct btrfs_root *root, BTRFS_INODE_PREALLOC | BTRFS_INODE_NODATASUM); btrfs_set_inode_nlink(leaf, inode_item, 1); btrfs_set_inode_transid(leaf, inode_item, trans->transid); - btrfs_set_inode_block_group(leaf, inode_item, - block_group->key.objectid); + btrfs_set_inode_block_group(leaf, inode_item, offset); btrfs_mark_buffer_dirty(leaf); btrfs_release_path(root, path); key.objectid = BTRFS_FREE_SPACE_OBJECTID; - key.offset = block_group->key.objectid; + key.offset = offset; key.type = 0; ret = btrfs_insert_empty_item(trans, root, path, &key, @@ -156,6 +163,22 @@ int create_free_space_inode(struct btrfs_root *root, return 0; } +int create_free_space_inode(struct btrfs_root *root, + struct btrfs_trans_handle *trans, + struct btrfs_block_group_cache *block_group, + struct btrfs_path *path) +{ + int ret; + u64 ino; + + ret = btrfs_find_free_objectid(root, &ino); + if (ret < 0) + return ret; + + return __create_free_space_inode(root, trans, path, ino, + block_group->key.objectid); +} + int btrfs_truncate_free_space_cache(struct btrfs_root *root, struct btrfs_trans_handle *trans, struct btrfs_path *path, @@ -208,16 +231,13 @@ static int readahead_cache(struct inode *inode) return 0; } -int load_free_space_cache(struct btrfs_fs_info *fs_info, - struct btrfs_block_group_cache *block_group) +int __load_free_space_cache(struct btrfs_root *root, struct inode *inode, + struct btrfs_free_space_ctl *ctl, + struct btrfs_path *path, u64 offset) { - struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; - struct btrfs_root *root = fs_info->tree_root; - struct inode *inode; struct btrfs_free_space_header *header; struct extent_buffer *leaf; struct page *page; - struct btrfs_path *path; u32 *checksums = NULL, *crc; char *disk_crcs = NULL; struct btrfs_key key; @@ -225,76 +245,47 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info, u64 num_entries; u64 num_bitmaps; u64 generation; - u64 used = btrfs_block_group_used(&block_group->item); u32 cur_crc = ~(u32)0; pgoff_t index = 0; unsigned long first_page_offset; int num_checksums; - int ret = 0; - - /* - * If we're unmounting then just return, since this does a search on the - * normal root and not the commit root and we could deadlock. - */ - smp_mb(); - if (fs_info->closing) - return 0; - - /* - * If this block group has been marked to be cleared for one reason or - * another then we can't trust the on disk cache, so just return. - */ - spin_lock(&block_group->lock); - if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) { - spin_unlock(&block_group->lock); - return 0; - } - spin_unlock(&block_group->lock); + int ret = 0, ret2; INIT_LIST_HEAD(&bitmaps); - path = btrfs_alloc_path(); - if (!path) - return 0; - - inode = lookup_free_space_inode(root, block_group, path); - if (IS_ERR(inode)) { - btrfs_free_path(path); - return 0; - } - /* Nothing in the space cache, goodbye */ - if (!i_size_read(inode)) { - btrfs_free_path(path); + if (!i_size_read(inode)) goto out; - } key.objectid = BTRFS_FREE_SPACE_OBJECTID; - key.offset = block_group->key.objectid; + key.offset = offset; key.type = 0; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); - if (ret) { - btrfs_free_path(path); + if (ret < 0) + goto out; + else if (ret > 0) { + btrfs_release_path(root, path); + ret = 0; goto out; } + ret = -1; + leaf = path->nodes[0]; header = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_free_space_header); num_entries = btrfs_free_space_entries(leaf, header); num_bitmaps = btrfs_free_space_bitmaps(leaf, header); generation = btrfs_free_space_generation(leaf, header); - btrfs_free_path(path); + btrfs_release_path(root, path); if (BTRFS_I(inode)->generation != generation) { printk(KERN_ERR "btrfs: free space inode generation (%llu) did" - " not match free space cache generation (%llu) for " - "block group %llu\n", + " not match free space cache generation (%llu)\n", (unsigned long long)BTRFS_I(inode)->generation, - (unsigned long long)generation, - (unsigned long long)block_group->key.objectid); - goto free_cache; + (unsigned long long)generation); + goto out; } if (!num_entries) @@ -311,10 +302,8 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info, goto out; ret = readahead_cache(inode); - if (ret) { - ret = 0; + if (ret) goto out; - } while (1) { struct btrfs_free_space_entry *entry; @@ -333,10 +322,8 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info, } page = grab_cache_page(inode->i_mapping, index); - if (!page) { - ret = 0; + if (!page) goto free_cache; - } if (!PageUptodate(page)) { btrfs_readpage(NULL, page); @@ -345,9 +332,7 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info, unlock_page(page); page_cache_release(page); printk(KERN_ERR "btrfs: error reading free " - "space cache: %llu\n", - (unsigned long long) - block_group->key.objectid); + "space cache\n"); goto free_cache; } } @@ -360,13 +345,10 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info, gen = addr + (sizeof(u32) * num_checksums); if (*gen != BTRFS_I(inode)->generation) { printk(KERN_ERR "btrfs: space cache generation" - " (%llu) does not match inode (%llu) " - "for block group %llu\n", + " (%llu) does not match inode (%llu)\n", (unsigned long long)*gen, (unsigned long long) - BTRFS_I(inode)->generation, - (unsigned long long) - block_group->key.objectid); + BTRFS_I(inode)->generation); kunmap(page); unlock_page(page); page_cache_release(page); @@ -382,9 +364,8 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info, PAGE_CACHE_SIZE - start_offset); btrfs_csum_final(cur_crc, (char *)&cur_crc); if (cur_crc != *crc) { - printk(KERN_ERR "btrfs: crc mismatch for page %lu in " - "block group %llu\n", index, - (unsigned long long)block_group->key.objectid); + printk(KERN_ERR "btrfs: crc mismatch for page %lu\n", + index); kunmap(page); unlock_page(page); page_cache_release(page); @@ -432,7 +413,7 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info, goto free_cache; } spin_lock(&ctl->tree_lock); - ret = link_free_space(ctl, e); + ret2 = link_free_space(ctl, e); ctl->total_bitmaps++; ctl->op->recalc_thresholds(ctl); spin_unlock(&ctl->tree_lock); @@ -471,42 +452,96 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info, index++; } - spin_lock(&ctl->tree_lock); - if (ctl->free_space != (block_group->key.offset - used - - block_group->bytes_super)) { - spin_unlock(&ctl->tree_lock); - printk(KERN_ERR "block group %llu has an wrong amount of free " - "space\n", block_group->key.objectid); - ret = 0; - goto free_cache; - } - spin_unlock(&ctl->tree_lock); - ret = 1; out: kfree(checksums); kfree(disk_crcs); - iput(inode); return ret; - free_cache: - /* This cache is bogus, make sure it gets cleared */ - spin_lock(&block_group->lock); - block_group->disk_cache_state = BTRFS_DC_CLEAR; - spin_unlock(&block_group->lock); - btrfs_remove_free_space_cache(block_group); + __btrfs_remove_free_space_cache(ctl); goto out; } -int btrfs_write_out_cache(struct btrfs_root *root, - struct btrfs_trans_handle *trans, - struct btrfs_block_group_cache *block_group, - struct btrfs_path *path) +int load_free_space_cache(struct btrfs_fs_info *fs_info, + struct btrfs_block_group_cache *block_group) { struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; + struct btrfs_root *root = fs_info->tree_root; + struct inode *inode; + struct btrfs_path *path; + int ret; + bool matched; + u64 used = btrfs_block_group_used(&block_group->item); + + /* + * If we're unmounting then just return, since this does a search on the + * normal root and not the commit root and we could deadlock. + */ + smp_mb(); + if (fs_info->closing) + return 0; + + /* + * If this block group has been marked to be cleared for one reason or + * another then we can't trust the on disk cache, so just return. + */ + spin_lock(&block_group->lock); + if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) { + spin_unlock(&block_group->lock); + return 0; + } + spin_unlock(&block_group->lock); + + path = btrfs_alloc_path(); + if (!path) + return 0; + + inode = lookup_free_space_inode(root, block_group, path); + if (IS_ERR(inode)) { + btrfs_free_path(path); + return 0; + } + + ret = __load_free_space_cache(fs_info->tree_root, inode, ctl, + path, block_group->key.objectid); + btrfs_free_path(path); + if (ret <= 0) + goto out; + + spin_lock(&ctl->tree_lock); + matched = (ctl->free_space == (block_group->key.offset - used - + block_group->bytes_super)); + spin_unlock(&ctl->tree_lock); + + if (!matched) { + __btrfs_remove_free_space_cache(ctl); + printk(KERN_ERR "block group %llu has an wrong amount of free " + "space\n", block_group->key.objectid); + ret = -1; + } +out: + if (ret < 0) { + /* This cache is bogus, make sure it gets cleared */ + spin_lock(&block_group->lock); + block_group->disk_cache_state = BTRFS_DC_CLEAR; + spin_unlock(&block_group->lock); + + printk(KERN_ERR "btrfs: failed to load free space cache " + "for block group %llu\n", block_group->key.objectid); + } + + iput(inode); + return ret; +} + +int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode, + struct btrfs_free_space_ctl *ctl, + struct btrfs_block_group_cache *block_group, + struct btrfs_trans_handle *trans, + struct btrfs_path *path, u64 offset) +{ struct btrfs_free_space_header *header; struct extent_buffer *leaf; - struct inode *inode; struct rb_node *node; struct list_head *pos, *n; struct page **pages; @@ -523,35 +558,18 @@ int btrfs_write_out_cache(struct btrfs_root *root, int index = 0, num_pages = 0; int entries = 0; int bitmaps = 0; - int ret = 0; + int ret = -1; bool next_page = false; bool out_of_space = false; - root = root->fs_info->tree_root; - INIT_LIST_HEAD(&bitmap_list); - spin_lock(&block_group->lock); - if (block_group->disk_cache_state < BTRFS_DC_SETUP) { - spin_unlock(&block_group->lock); - return 0; - } - spin_unlock(&block_group->lock); - - inode = lookup_free_space_inode(root, block_group, path); - if (IS_ERR(inode)) - return 0; - - if (!i_size_read(inode)) { - iput(inode); - return 0; - } - node = rb_first(&ctl->free_space_offset); - if (!node) { - iput(inode); + if (!node) return 0; - } + + if (!i_size_read(inode)) + return -1; num_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; @@ -561,16 +579,13 @@ int btrfs_write_out_cache(struct btrfs_root *root, /* We need a checksum per page. */ crc = checksums = kzalloc(sizeof(u32) * num_pages, GFP_NOFS); - if (!crc) { - iput(inode); - return 0; - } + if (!crc) + return -1; pages = kzalloc(sizeof(struct page *) * num_pages, GFP_NOFS); if (!pages) { kfree(crc); - iput(inode); - return 0; + return -1; } /* Since the first page has all of our checksums and our generation we @@ -580,7 +595,7 @@ int btrfs_write_out_cache(struct btrfs_root *root, first_page_offset = (sizeof(u32) * num_pages) + sizeof(u64); /* Get the cluster for this block_group if it exists */ - if (!list_empty(&block_group->cluster_list)) + if (block_group && !list_empty(&block_group->cluster_list)) cluster = list_entry(block_group->cluster_list.next, struct btrfs_free_cluster, block_group_list); @@ -622,7 +637,8 @@ int btrfs_write_out_cache(struct btrfs_root *root, * When searching for pinned extents, we need to start at our start * offset. */ - start = block_group->key.objectid; + if (block_group) + start = block_group->key.objectid; /* Write out the extent entries */ do { @@ -680,8 +696,9 @@ int btrfs_write_out_cache(struct btrfs_root *root, * We want to add any pinned extents to our free space cache * so we don't leak the space */ - while (!next_page && (start < block_group->key.objectid + - block_group->key.offset)) { + while (block_group && !next_page && + (start < block_group->key.objectid + + block_group->key.offset)) { ret = find_first_extent_bit(unpin, start, &start, &end, EXTENT_DIRTY); if (ret) { @@ -799,12 +816,12 @@ int btrfs_write_out_cache(struct btrfs_root *root, filemap_write_and_wait(inode->i_mapping); key.objectid = BTRFS_FREE_SPACE_OBJECTID; - key.offset = block_group->key.objectid; + key.offset = offset; key.type = 0; ret = btrfs_search_slot(trans, root, &key, path, 1, 1); if (ret < 0) { - ret = 0; + ret = -1; clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, bytes - 1, EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING, 0, 0, NULL, GFP_NOFS); @@ -817,8 +834,8 @@ int btrfs_write_out_cache(struct btrfs_root *root, path->slots[0]--; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID || - found_key.offset != block_group->key.objectid) { - ret = 0; + found_key.offset != offset) { + ret = -1; clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, bytes - 1, EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING, 0, 0, NULL, @@ -838,16 +855,49 @@ int btrfs_write_out_cache(struct btrfs_root *root, ret = 1; out_free: - if (ret == 0) { + if (ret != 1) { invalidate_inode_pages2_range(inode->i_mapping, 0, index); - spin_lock(&block_group->lock); - block_group->disk_cache_state = BTRFS_DC_ERROR; - spin_unlock(&block_group->lock); BTRFS_I(inode)->generation = 0; } kfree(checksums); kfree(pages); btrfs_update_inode(trans, root, inode); + return ret; +} + +int btrfs_write_out_cache(struct btrfs_root *root, + struct btrfs_trans_handle *trans, + struct btrfs_block_group_cache *block_group, + struct btrfs_path *path) +{ + struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; + struct inode *inode; + int ret = 0; + + root = root->fs_info->tree_root; + + spin_lock(&block_group->lock); + if (block_group->disk_cache_state < BTRFS_DC_SETUP) { + spin_unlock(&block_group->lock); + return 0; + } + spin_unlock(&block_group->lock); + + inode = lookup_free_space_inode(root, block_group, path); + if (IS_ERR(inode)) + return 0; + + ret = __btrfs_write_out_cache(root, inode, ctl, block_group, trans, + path, block_group->key.objectid); + if (ret < 0) { + spin_lock(&block_group->lock); + block_group->disk_cache_state = BTRFS_DC_ERROR; + spin_unlock(&block_group->lock); + + printk(KERN_ERR "btrfs: failed to write free space cace " + "for block group %llu\n", block_group->key.objectid); + } + iput(inode); return ret; } -- 2.45.2