btrfs-progs: check: enable repair in lowmem mode
[platform/upstream/btrfs-progs.git] / cmds-check.c
index 006edbd..89e12c1 100644 (file)
@@ -85,7 +85,7 @@ enum btrfs_check_mode {
 static enum btrfs_check_mode check_mode = CHECK_MODE_DEFAULT;
 
 struct extent_backref {
-       struct list_head list;
+       struct rb_node node;
        unsigned int is_data:1;
        unsigned int found_extent_tree:1;
        unsigned int full_backref:1;
@@ -93,9 +93,9 @@ struct extent_backref {
        unsigned int broken:1;
 };
 
-static inline struct extent_backref* to_extent_backref(struct list_head *entry)
+static inline struct extent_backref* rb_node_to_extent_backref(struct rb_node *node)
 {
-       return list_entry(entry, struct extent_backref, list);
+       return rb_entry(node, struct extent_backref, node);
 }
 
 struct data_backref {
@@ -136,6 +136,51 @@ static inline struct data_backref* to_data_backref(struct extent_backref *back)
        return container_of(back, struct data_backref, node);
 }
 
+static int compare_data_backref(struct rb_node *node1, struct rb_node *node2)
+{
+       struct extent_backref *ext1 = rb_node_to_extent_backref(node1);
+       struct extent_backref *ext2 = rb_node_to_extent_backref(node2);
+       struct data_backref *back1 = to_data_backref(ext1);
+       struct data_backref *back2 = to_data_backref(ext2);
+
+       WARN_ON(!ext1->is_data);
+       WARN_ON(!ext2->is_data);
+
+       /* parent and root are a union, so this covers both */
+       if (back1->parent > back2->parent)
+               return 1;
+       if (back1->parent < back2->parent)
+               return -1;
+
+       /* This is a full backref and the parents match. */
+       if (back1->node.full_backref)
+               return 0;
+
+       if (back1->owner > back2->owner)
+               return 1;
+       if (back1->owner < back2->owner)
+               return -1;
+
+       if (back1->offset > back2->offset)
+               return 1;
+       if (back1->offset < back2->offset)
+               return -1;
+
+       if (back1->found_ref && back2->found_ref) {
+               if (back1->disk_bytenr > back2->disk_bytenr)
+                       return 1;
+               if (back1->disk_bytenr < back2->disk_bytenr)
+                       return -1;
+
+               if (back1->bytes > back2->bytes)
+                       return 1;
+               if (back1->bytes < back2->bytes)
+                       return -1;
+       }
+
+       return 0;
+}
+
 /*
  * Much like data_backref, just removed the undetermined members
  * and change it to use list_head.
@@ -164,12 +209,54 @@ static inline struct tree_backref* to_tree_backref(struct extent_backref *back)
        return container_of(back, struct tree_backref, node);
 }
 
+static int compare_tree_backref(struct rb_node *node1, struct rb_node *node2)
+{
+       struct extent_backref *ext1 = rb_node_to_extent_backref(node1);
+       struct extent_backref *ext2 = rb_node_to_extent_backref(node2);
+       struct tree_backref *back1 = to_tree_backref(ext1);
+       struct tree_backref *back2 = to_tree_backref(ext2);
+
+       WARN_ON(ext1->is_data);
+       WARN_ON(ext2->is_data);
+
+       /* parent and root are a union, so this covers both */
+       if (back1->parent > back2->parent)
+               return 1;
+       if (back1->parent < back2->parent)
+               return -1;
+
+       return 0;
+}
+
+static int compare_extent_backref(struct rb_node *node1, struct rb_node *node2)
+{
+       struct extent_backref *ext1 = rb_node_to_extent_backref(node1);
+       struct extent_backref *ext2 = rb_node_to_extent_backref(node2);
+
+       if (ext1->is_data > ext2->is_data)
+               return 1;
+
+       if (ext1->is_data < ext2->is_data)
+               return -1;
+
+       if (ext1->full_backref > ext2->full_backref)
+               return 1;
+       if (ext1->full_backref < ext2->full_backref)
+               return -1;
+
+       if (ext1->is_data)
+               return compare_data_backref(node1, node2);
+       else
+               return compare_tree_backref(node1, node2);
+}
+
 /* Explicit initialization for extent_record::flag_block_full_backref */
 enum { FLAG_UNSET = 2 };
 
 struct extent_record {
        struct list_head backrefs;
        struct list_head dups;
+       struct rb_root backref_tree;
        struct list_head list;
        struct cache_extent cache;
        struct btrfs_disk_key parent_key;
@@ -5067,6 +5154,65 @@ out:
        return ret;
 }
 
+static struct tree_backref *find_tree_backref(struct extent_record *rec,
+                                               u64 parent, u64 root)
+{
+       struct rb_node *node;
+       struct tree_backref *back = NULL;
+       struct tree_backref match = {
+               .node = {
+                       .is_data = 0,
+               },
+       };
+
+       if (parent) {
+               match.parent = parent;
+               match.node.full_backref = 1;
+       } else {
+               match.root = root;
+       }
+
+       node = rb_search(&rec->backref_tree, &match.node.node,
+                        (rb_compare_keys)compare_extent_backref, NULL);
+       if (node)
+               back = to_tree_backref(rb_node_to_extent_backref(node));
+
+       return back;
+}
+
+static struct data_backref *find_data_backref(struct extent_record *rec,
+                                               u64 parent, u64 root,
+                                               u64 owner, u64 offset,
+                                               int found_ref,
+                                               u64 disk_bytenr, u64 bytes)
+{
+       struct rb_node *node;
+       struct data_backref *back = NULL;
+       struct data_backref match = {
+               .node = {
+                       .is_data = 1,
+               },
+               .owner = owner,
+               .offset = offset,
+               .bytes = bytes,
+               .found_ref = found_ref,
+               .disk_bytenr = disk_bytenr,
+       };
+
+       if (parent) {
+               match.parent = parent;
+               match.node.full_backref = 1;
+       } else {
+               match.root = root;
+       }
+
+       node = rb_search(&rec->backref_tree, &match.node.node,
+                        (rb_compare_keys)compare_extent_backref, NULL);
+       if (node)
+               back = to_data_backref(rb_node_to_extent_backref(node));
+
+       return back;
+}
 /*
  * Iterate all item on the tree and call check_inode_item() to check.
  *
@@ -5331,23 +5477,21 @@ static int do_check_fs_roots(struct btrfs_fs_info *fs_info,
 
 static int all_backpointers_checked(struct extent_record *rec, int print_errs)
 {
-       struct list_head *cur = rec->backrefs.next;
-       struct extent_backref *back;
+       struct extent_backref *back, *tmp;
        struct tree_backref *tback;
        struct data_backref *dback;
        u64 found = 0;
        int err = 0;
 
-       while(cur != &rec->backrefs) {
-               back = to_extent_backref(cur);
-               cur = cur->next;
+       rbtree_postorder_for_each_entry_safe(back, tmp,
+                                            &rec->backref_tree, node) {
                if (!back->found_extent_tree) {
                        err = 1;
                        if (!print_errs)
                                goto out;
                        if (back->is_data) {
                                dback = to_data_backref(back);
-                               fprintf(stderr, "Backref %llu %s %llu"
+                               fprintf(stderr, "Data backref %llu %s %llu"
                                        " owner %llu offset %llu num_refs %lu"
                                        " not found in extent tree\n",
                                        (unsigned long long)rec->start,
@@ -5361,7 +5505,7 @@ static int all_backpointers_checked(struct extent_record *rec, int print_errs)
                                        (unsigned long)dback->num_refs);
                        } else {
                                tback = to_tree_backref(back);
-                               fprintf(stderr, "Backref %llu parent %llu"
+                               fprintf(stderr, "Tree backref %llu parent %llu"
                                        " root %llu not found in extent tree\n",
                                        (unsigned long long)rec->start,
                                        (unsigned long long)tback->parent,
@@ -5443,17 +5587,16 @@ out:
        return err;
 }
 
-static int free_all_extent_backrefs(struct extent_record *rec)
+static void __free_one_backref(struct rb_node *node)
 {
-       struct extent_backref *back;
-       struct list_head *cur;
-       while (!list_empty(&rec->backrefs)) {
-               cur = rec->backrefs.next;
-               back = to_extent_backref(cur);
-               list_del(cur);
-               free(back);
-       }
-       return 0;
+       struct extent_backref *back = rb_node_to_extent_backref(node);
+
+       free(back);
+}
+
+static void free_all_extent_backrefs(struct extent_record *rec)
+{
+       rb_free_nodes(&rec->backref_tree, __free_one_backref);
 }
 
 static void free_extent_record_cache(struct cache_tree *extent_cache)
@@ -5492,7 +5635,7 @@ static int check_owner_ref(struct btrfs_root *root,
                            struct extent_record *rec,
                            struct extent_buffer *buf)
 {
-       struct extent_backref *node;
+       struct extent_backref *node, *tmp;
        struct tree_backref *back;
        struct btrfs_root *ref_root;
        struct btrfs_key key;
@@ -5502,7 +5645,8 @@ static int check_owner_ref(struct btrfs_root *root,
        int found = 0;
        int ret;
 
-       list_for_each_entry(node, &rec->backrefs, list) {
+       rbtree_postorder_for_each_entry_safe(node, tmp,
+                                            &rec->backref_tree, node) {
                if (node->is_data)
                        continue;
                if (!node->found_ref)
@@ -5547,14 +5691,12 @@ static int check_owner_ref(struct btrfs_root *root,
 
 static int is_extent_tree_record(struct extent_record *rec)
 {
-       struct list_head *cur = rec->backrefs.next;
-       struct extent_backref *node;
+       struct extent_backref *node, *tmp;
        struct tree_backref *back;
        int is_extent = 0;
 
-       while(cur != &rec->backrefs) {
-               node = to_extent_backref(cur);
-               cur = cur->next;
+       rbtree_postorder_for_each_entry_safe(node, tmp,
+                                            &rec->backref_tree, node) {
                if (node->is_data)
                        return 0;
                back = to_tree_backref(node);
@@ -5919,6 +6061,7 @@ static int check_block(struct btrfs_root *root,
        return ret;
 }
 
+#if 0
 static struct tree_backref *find_tree_backref(struct extent_record *rec,
                                                u64 parent, u64 root)
 {
@@ -5946,6 +6089,7 @@ static struct tree_backref *find_tree_backref(struct extent_record *rec,
        }
        return NULL;
 }
+#endif
 
 static struct tree_backref *alloc_tree_backref(struct extent_record *rec,
                                                u64 parent, u64 root)
@@ -5962,11 +6106,11 @@ static struct tree_backref *alloc_tree_backref(struct extent_record *rec,
                ref->root = root;
                ref->node.full_backref = 0;
        }
-       list_add_tail(&ref->node.list, &rec->backrefs);
 
        return ref;
 }
 
+#if 0
 static struct data_backref *find_data_backref(struct extent_record *rec,
                                                u64 parent, u64 root,
                                                u64 owner, u64 offset,
@@ -6003,6 +6147,7 @@ static struct data_backref *find_data_backref(struct extent_record *rec,
        }
        return NULL;
 }
+#endif
 
 static struct data_backref *alloc_data_backref(struct extent_record *rec,
                                                u64 parent, u64 root,
@@ -6030,7 +6175,6 @@ static struct data_backref *alloc_data_backref(struct extent_record *rec,
        ref->bytes = max_size;
        ref->found_ref = 0;
        ref->num_refs = 0;
-       list_add_tail(&ref->node.list, &rec->backrefs);
        if (max_size > rec->max_size)
                rec->max_size = max_size;
        return ref;
@@ -6063,12 +6207,12 @@ static void check_extent_type(struct extent_record *rec)
         * Check SYSTEM extent, as it's also marked as metadata, we can only
         * make sure it's a SYSTEM extent by its backref
         */
-       if (!list_empty(&rec->backrefs)) {
+       if (!RB_EMPTY_ROOT(&rec->backref_tree)) {
                struct extent_backref *node;
                struct tree_backref *tback;
                u64 bg_type;
 
-               node = to_extent_backref(rec->backrefs.next);
+               node = rb_node_to_extent_backref(rb_first(&rec->backref_tree));
                if (node->is_data) {
                        /* tree block shouldn't have data backref */
                        rec->wrong_chunk_type = 1;
@@ -6119,6 +6263,7 @@ static int add_extent_rec_nolookup(struct cache_tree *extent_cache,
        INIT_LIST_HEAD(&rec->backrefs);
        INIT_LIST_HEAD(&rec->dups);
        INIT_LIST_HEAD(&rec->list);
+       rec->backref_tree = RB_ROOT;
        memcpy(&rec->parent_key, &tmpl->parent_key, sizeof(tmpl->parent_key));
        rec->cache.start = tmpl->start;
        rec->cache.size = tmpl->nr;
@@ -6251,6 +6396,7 @@ static int add_tree_backref(struct cache_tree *extent_cache, u64 bytenr,
        struct tree_backref *back;
        struct cache_extent *cache;
        int ret;
+       bool insert = false;
 
        cache = lookup_cache_extent(extent_cache, bytenr, 1);
        if (!cache) {
@@ -6285,6 +6431,7 @@ static int add_tree_backref(struct cache_tree *extent_cache, u64 bytenr,
                back = alloc_tree_backref(rec, parent, root);
                if (!back)
                        return -ENOMEM;
+               insert = true;
        }
 
        if (found_ref) {
@@ -6306,6 +6453,9 @@ static int add_tree_backref(struct cache_tree *extent_cache, u64 bytenr,
                }
                back->node.found_extent_tree = 1;
        }
+       if (insert)
+               WARN_ON(rb_insert(&rec->backref_tree, &back->node.node,
+                       compare_extent_backref));
        check_extent_type(rec);
        maybe_free_extent_rec(extent_cache, rec);
        return 0;
@@ -6319,6 +6469,7 @@ static int add_data_backref(struct cache_tree *extent_cache, u64 bytenr,
        struct data_backref *back;
        struct cache_extent *cache;
        int ret;
+       bool insert = false;
 
        cache = lookup_cache_extent(extent_cache, bytenr, 1);
        if (!cache) {
@@ -6358,6 +6509,7 @@ static int add_data_backref(struct cache_tree *extent_cache, u64 bytenr,
                back = alloc_data_backref(rec, parent, root, owner, offset,
                                          max_size);
                BUG_ON(!back);
+               insert = true;
        }
 
        if (found_ref) {
@@ -6366,8 +6518,16 @@ static int add_data_backref(struct cache_tree *extent_cache, u64 bytenr,
                        BUG_ON(back->bytes != max_size);
                back->node.found_ref = 1;
                back->found_ref += 1;
-               back->bytes = max_size;
-               back->disk_bytenr = bytenr;
+               if (back->bytes != max_size || back->disk_bytenr != bytenr) {
+                       back->bytes = max_size;
+                       back->disk_bytenr = bytenr;
+
+                       /* Need to reinsert if not already in the tree */
+                       if (!insert) {
+                               rb_erase(&back->node.node, &rec->backref_tree);
+                               insert = true;
+                       }
+               }
                rec->refs += 1;
                rec->content_checked = 1;
                rec->owner_ref_checked = 1;
@@ -6386,6 +6546,10 @@ static int add_data_backref(struct cache_tree *extent_cache, u64 bytenr,
                back->num_refs = num_refs;
                back->node.found_extent_tree = 1;
        }
+       if (insert)
+               WARN_ON(rb_insert(&rec->backref_tree, &back->node.node,
+                       compare_extent_backref));
+
        maybe_free_extent_rec(extent_cache, rec);
        return 0;
 }
@@ -8041,7 +8205,7 @@ static int free_extent_hook(struct btrfs_trans_handle *trans,
                        back->node.found_extent_tree = 0;
 
                if (!back->node.found_extent_tree && back->node.found_ref) {
-                       list_del(&back->node.list);
+                       rb_erase(&back->node.node, &rec->backref_tree);
                        free(back);
                }
        } else {
@@ -8060,7 +8224,7 @@ static int free_extent_hook(struct btrfs_trans_handle *trans,
                        back->node.found_extent_tree = 0;
                }
                if (!back->node.found_extent_tree && back->node.found_ref) {
-                       list_del(&back->node.list);
+                       rb_erase(&back->node.node, &rec->backref_tree);
                        free(back);
                }
        }
@@ -8501,7 +8665,7 @@ out:
 static int verify_backrefs(struct btrfs_fs_info *info, struct btrfs_path *path,
                           struct extent_record *rec)
 {
-       struct extent_backref *back;
+       struct extent_backref *back, *tmp;
        struct data_backref *dback;
        struct extent_entry *entry, *best = NULL;
        LIST_HEAD(entries);
@@ -8517,7 +8681,8 @@ static int verify_backrefs(struct btrfs_fs_info *info, struct btrfs_path *path,
        if (rec->metadata)
                return 0;
 
-       list_for_each_entry(back, &rec->backrefs, list) {
+       rbtree_postorder_for_each_entry_safe(back, tmp,
+                                            &rec->backref_tree, node) {
                if (back->full_backref || !back->is_data)
                        continue;
 
@@ -8643,7 +8808,8 @@ static int verify_backrefs(struct btrfs_fs_info *info, struct btrfs_path *path,
         * Ok great we all agreed on an extent record, let's go find the real
         * references and fix up the ones that don't match.
         */
-       list_for_each_entry(back, &rec->backrefs, list) {
+       rbtree_postorder_for_each_entry_safe(back, tmp,
+                                            &rec->backref_tree, node) {
                if (back->full_backref || !back->is_data)
                        continue;
 
@@ -8867,7 +9033,7 @@ static int find_possible_backrefs(struct btrfs_fs_info *info,
                                  struct extent_record *rec)
 {
        struct btrfs_root *root;
-       struct extent_backref *back;
+       struct extent_backref *back, *tmp;
        struct data_backref *dback;
        struct cache_extent *cache;
        struct btrfs_file_extent_item *fi;
@@ -8875,7 +9041,8 @@ static int find_possible_backrefs(struct btrfs_fs_info *info,
        u64 bytenr, bytes;
        int ret;
 
-       list_for_each_entry(back, &rec->backrefs, list) {
+       rbtree_postorder_for_each_entry_safe(back, tmp,
+                                            &rec->backref_tree, node) {
                /* Don't care about full backrefs (poor unloved backrefs) */
                if (back->full_backref || !back->is_data)
                        continue;
@@ -8963,7 +9130,7 @@ static int record_orphan_data_extents(struct btrfs_fs_info *fs_info,
 {
        struct btrfs_key key;
        struct btrfs_root *dest_root;
-       struct extent_backref *back;
+       struct extent_backref *back, *tmp;
        struct data_backref *dback;
        struct orphan_data_extent *orphan;
        struct btrfs_path path;
@@ -8973,7 +9140,8 @@ static int record_orphan_data_extents(struct btrfs_fs_info *fs_info,
        if (rec->metadata)
                return 1;
        btrfs_init_path(&path);
-       list_for_each_entry(back, &rec->backrefs, list) {
+       rbtree_postorder_for_each_entry_safe(back, tmp,
+                                            &rec->backref_tree, node) {
                if (back->full_backref || !back->is_data ||
                    !back->found_extent_tree)
                        continue;
@@ -9041,9 +9209,8 @@ static int fixup_extent_refs(struct btrfs_fs_info *info,
        struct btrfs_trans_handle *trans = NULL;
        int ret;
        struct btrfs_path path;
-       struct list_head *cur = rec->backrefs.next;
        struct cache_extent *cache;
-       struct extent_backref *back;
+       struct extent_backref *back, *tmp;
        int allocated = 0;
        u64 flags = 0;
 
@@ -9091,10 +9258,8 @@ static int fixup_extent_refs(struct btrfs_fs_info *info,
        }
 
        /* step three, recreate all the refs we did find */
-       while(cur != &rec->backrefs) {
-               back = to_extent_backref(cur);
-               cur = cur->next;
-
+       rbtree_postorder_for_each_entry_safe(back, tmp,
+                                            &rec->backref_tree, node) {
                /*
                 * if we didn't find any references, don't create a
                 * new extent record
@@ -12907,12 +13072,10 @@ int cmd_check(int argc, char **argv)
        }
 
        /*
-        * Not supported yet
+        * experimental and dangerous
         */
-       if (repair && check_mode == CHECK_MODE_LOWMEM) {
-               error("low memory mode doesn't support repair yet");
-               exit(1);
-       }
+       if (repair && check_mode == CHECK_MODE_LOWMEM)
+               warning("low-memory mode repair support is only partial");
 
        radix_tree_init();
        cache_tree_init(&root_cache);
@@ -12947,6 +13110,8 @@ int cmd_check(int argc, char **argv)
                        warning(
                        "filesystem mounted, continuing because of --force");
                }
+               /* A block device is mounted in exclusive mode by kernel */
+               ctree_flags &= ~OPEN_CTREE_EXCLUSIVE;
        }
 
        /* only allow partial opening under repair mode */