From e7d4cb6bc19658646357eeff134645cd9bc3479f Mon Sep 17 00:00:00 2001 From: Tao Ma Date: Mon, 18 Aug 2008 17:38:44 +0800 Subject: ocfs2: Abstract ocfs2_extent_tree in b-tree operations. In the old extent tree operation, we take the hypothesis that we are using the ocfs2_extent_list in ocfs2_dinode as the tree root. As xattr will also use ocfs2_extent_list to store large value for a xattr entry, we refactor the tree operation so that xattr can use it directly. The refactoring includes 4 steps: 1. Abstract set/get of last_eb_blk and update_clusters since they may be stored in different location for dinode and xattr. 2. Add a new structure named ocfs2_extent_tree to indicate the extent tree the operation will work on. 3. Remove all the use of fe_bh and di, use root_bh and root_el in extent tree instead. So now all the fe_bh is replaced with et->root_bh, el with root_el accordingly. 4. Make ocfs2_lock_allocators generic. Now it is limited to be only used in file extend allocation. But the whole function is useful when we want to store large EAs. Note: This patch doesn't touch ocfs2_commit_truncate() since it is not used for anything other than truncate inode data btrees. Signed-off-by: Tao Ma Signed-off-by: Mark Fasheh --- fs/ocfs2/suballoc.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) (limited to 'fs/ocfs2/suballoc.c') diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c index 2a817bca1ddb..b642c825fb7c 100644 --- a/fs/ocfs2/suballoc.c +++ b/fs/ocfs2/suballoc.c @@ -1894,3 +1894,85 @@ static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe) (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno); } } + +/* + * For a given allocation, determine which allocators will need to be + * accessed, and lock them, reserving the appropriate number of bits. + * + * Sparse file systems call this from ocfs2_write_begin_nolock() + * and ocfs2_allocate_unwritten_extents(). + * + * File systems which don't support holes call this from + * ocfs2_extend_allocation(). + */ +int ocfs2_lock_allocators(struct inode *inode, struct buffer_head *root_bh, + struct ocfs2_extent_list *root_el, + u32 clusters_to_add, u32 extents_to_split, + struct ocfs2_alloc_context **data_ac, + struct ocfs2_alloc_context **meta_ac) +{ + int ret = 0, num_free_extents; + unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split; + struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); + + *meta_ac = NULL; + if (data_ac) + *data_ac = NULL; + + BUG_ON(clusters_to_add != 0 && data_ac == NULL); + + num_free_extents = ocfs2_num_free_extents(osb, inode, root_bh, + OCFS2_DINODE_EXTENT); + if (num_free_extents < 0) { + ret = num_free_extents; + mlog_errno(ret); + goto out; + } + + /* + * Sparse allocation file systems need to be more conservative + * with reserving room for expansion - the actual allocation + * happens while we've got a journal handle open so re-taking + * a cluster lock (because we ran out of room for another + * extent) will violate ordering rules. + * + * Most of the time we'll only be seeing this 1 cluster at a time + * anyway. + * + * Always lock for any unwritten extents - we might want to + * add blocks during a split. + */ + if (!num_free_extents || + (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) { + ret = ocfs2_reserve_new_metadata(osb, root_el, meta_ac); + if (ret < 0) { + if (ret != -ENOSPC) + mlog_errno(ret); + goto out; + } + } + + if (clusters_to_add == 0) + goto out; + + ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac); + if (ret < 0) { + if (ret != -ENOSPC) + mlog_errno(ret); + goto out; + } + +out: + if (ret) { + if (*meta_ac) { + ocfs2_free_alloc_context(*meta_ac); + *meta_ac = NULL; + } + + /* + * We cannot have an error and a non null *data_ac. + */ + } + + return ret; +} -- cgit v1.2.3