1 files changed, 204 insertions, 0 deletions

diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index 02b6e7af8edb..873bb99fc2ff 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -2957,6 +2957,210 @@ int ocfs2_truncate_log_init(struct ocfs2_super *osb)
         return status;
 }
 
+/*
+ * Delayed de-allocation of suballocator blocks.
+ *
+ * Some sets of block de-allocations might involve multiple suballocator inodes.
+ *
+ * The locking for this can get extremely complicated, especially when
+ * the suballocator inodes to delete from aren't known until deep
+ * within an unrelated codepath.
+ *
+ * ocfs2_extent_block structures are a good example of this - an inode
+ * btree could have been grown by any number of nodes each allocating
+ * out of their own suballoc inode.
+ *
+ * These structures allow the delay of block de-allocation until a
+ * later time, when locking of multiple cluster inodes won't cause
+ * deadlock.
+ */
+
+/*
+ * Describes a single block free from a suballocator
+ */
+struct ocfs2_cached_block_free {
+        struct ocfs2_cached_block_free          *free_next;
+        u64                                     free_blk;
+        unsigned int                            free_bit;
+};
+
+struct ocfs2_per_slot_free_list {
+        struct ocfs2_per_slot_free_list         *f_next_suballocator;
+        int                                     f_inode_type;
+        int                                     f_slot;
+        struct ocfs2_cached_block_free          *f_first;
+};
+
+static int ocfs2_free_cached_items(struct ocfs2_super *osb,
+                                   int sysfile_type,
+                                   int slot,
+                                   struct ocfs2_cached_block_free *head)
+{
+        int ret;
+        u64 bg_blkno;
+        handle_t *handle;
+        struct inode *inode;
+        struct buffer_head *di_bh = NULL;
+        struct ocfs2_cached_block_free *tmp;
+
+        inode = ocfs2_get_system_file_inode(osb, sysfile_type, slot);
+        if (!inode) {
+                ret = -EINVAL;
+                mlog_errno(ret);
+                goto out;
+        }
+
+        mutex_lock(&inode->i_mutex);
+
+        ret = ocfs2_meta_lock(inode, &di_bh, 1);
+        if (ret) {
+                mlog_errno(ret);
+                goto out_mutex;
+        }
+
+        handle = ocfs2_start_trans(osb, OCFS2_SUBALLOC_FREE);
+        if (IS_ERR(handle)) {
+                ret = PTR_ERR(handle);
+                mlog_errno(ret);
+                goto out_unlock;
+        }
+
+        while (head) {
+                bg_blkno = ocfs2_which_suballoc_group(head->free_blk,
+                                                      head->free_bit);
+                mlog(0, "Free bit: (bit %u, blkno %llu)\n",
+                     head->free_bit, (unsigned long long)head->free_blk);
+
+                ret = ocfs2_free_suballoc_bits(handle, inode, di_bh,
+                                               head->free_bit, bg_blkno, 1);
+                if (ret) {
+                        mlog_errno(ret);
+                        goto out_journal;
+                }
+
+                ret = ocfs2_extend_trans(handle, OCFS2_SUBALLOC_FREE);
+                if (ret) {
+                        mlog_errno(ret);
+                        goto out_journal;
+                }
+
+                tmp = head;
+                head = head->free_next;
+                kfree(tmp);
+        }
+
+out_journal:
+        ocfs2_commit_trans(osb, handle);
+
+out_unlock:
+        ocfs2_meta_unlock(inode, 1);
+        brelse(di_bh);
+out_mutex:
+        mutex_unlock(&inode->i_mutex);
+        iput(inode);
+out:
+        while(head) {
+                /* Premature exit may have left some dangling items. */
+                tmp = head;
+                head = head->free_next;
+                kfree(tmp);
+        }
+
+        return ret;
+}
+
+int ocfs2_run_deallocs(struct ocfs2_super *osb,
+                       struct ocfs2_cached_dealloc_ctxt *ctxt)
+{
+        int ret = 0, ret2;
+        struct ocfs2_per_slot_free_list *fl;
+
+        if (!ctxt)
+                return 0;
+
+        while (ctxt->c_first_suballocator) {
+                fl = ctxt->c_first_suballocator;
+
+                if (fl->f_first) {
+                        mlog(0, "Free items: (type %u, slot %d)\n",
+                             fl->f_inode_type, fl->f_slot);
+                        ret2 = ocfs2_free_cached_items(osb, fl->f_inode_type,
+                                                       fl->f_slot, fl->f_first);
+                        if (ret2)
+                                mlog_errno(ret2);
+                        if (!ret)
+                                ret = ret2;
+                }
+
+                ctxt->c_first_suballocator = fl->f_next_suballocator;
+                kfree(fl);
+        }
+
+        return ret;
+}
+
+static struct ocfs2_per_slot_free_list *
+ocfs2_find_per_slot_free_list(int type,
+                              int slot,
+                              struct ocfs2_cached_dealloc_ctxt *ctxt)
+{
+        struct ocfs2_per_slot_free_list *fl = ctxt->c_first_suballocator;
+
+        while (fl) {
+                if (fl->f_inode_type == type && fl->f_slot == slot)
+                        return fl;
+
+                fl = fl->f_next_suballocator;
+        }
+
+        fl = kmalloc(sizeof(*fl), GFP_NOFS);
+        if (fl) {
+                fl->f_inode_type = type;
+                fl->f_slot = slot;
+                fl->f_first = NULL;
+                fl->f_next_suballocator = ctxt->c_first_suballocator;
+
+                ctxt->c_first_suballocator = fl;
+        }
+        return fl;
+}
+
+static int ocfs2_cache_block_dealloc(struct ocfs2_cached_dealloc_ctxt *ctxt,
+                                     int type, int slot, u64 blkno,
+                                     unsigned int bit)
+{
+        int ret;
+        struct ocfs2_per_slot_free_list *fl;
+        struct ocfs2_cached_block_free *item;
+
+        fl = ocfs2_find_per_slot_free_list(type, slot, ctxt);
+        if (fl == NULL) {
+                ret = -ENOMEM;
+                mlog_errno(ret);
+                goto out;
+        }
+
+        item = kmalloc(sizeof(*item), GFP_NOFS);
+        if (item == NULL) {
+                ret = -ENOMEM;
+                mlog_errno(ret);
+                goto out;
+        }
+
+        mlog(0, "Insert: (type %d, slot %u, bit %u, blk %llu)\n",
+             type, slot, bit, (unsigned long long)blkno);
+
+        item->free_blk = blkno;
+        item->free_bit = bit;
+        item->free_next = fl->f_first;
+
+        fl->f_first = item;
+
+        ret = 0;
+out:
+        return ret;
+}
+
 /* This function will figure out whether the currently last extent
  * block will be deleted, and if it will, what the new last extent
  * block will be so we can update his h_next_leaf_blk field, as well