#include "ctree.h"
#include "disk-io.h"
#include "backref.h"
+#include "ulist.h"
+#include "transaction.h"
+#include "delayed-ref.h"
struct __data_ref {
struct list_head list;
u64 disk_byte;
};
+/*
+ * this structure records all encountered refs on the way up to the root
+ */
+struct __prelim_ref {
+ struct list_head list;
+ u64 root_id;
+ struct btrfs_key key;
+ int level;
+ int count;
+ u64 parent;
+ u64 wanted_disk_byte;
+};
+
+static int __add_prelim_ref(struct list_head *head, u64 root_id,
+ struct btrfs_key *key, int level, u64 parent,
+ u64 wanted_disk_byte, int count)
+{
+ struct __prelim_ref *ref;
+
+ /* in case we're adding delayed refs, we're holding the refs spinlock */
+ ref = kmalloc(sizeof(*ref), GFP_ATOMIC);
+ if (!ref)
+ return -ENOMEM;
+
+ ref->root_id = root_id;
+ if (key)
+ ref->key = *key;
+ else
+ memset(&ref->key, 0, sizeof(ref->key));
+
+ ref->level = level;
+ ref->count = count;
+ ref->parent = parent;
+ ref->wanted_disk_byte = wanted_disk_byte;
+ list_add_tail(&ref->list, head);
+
+ return 0;
+}
+
+static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,
+ struct ulist *parents,
+ struct extent_buffer *eb, int level,
+ u64 wanted_objectid, u64 wanted_disk_byte)
+{
+ int ret;
+ int slot;
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_key key;
+ u64 disk_byte;
+
+add_parent:
+ ret = ulist_add(parents, eb->start, 0, GFP_NOFS);
+ if (ret < 0)
+ return ret;
+
+ if (level != 0)
+ return 0;
+
+ /*
+ * if the current leaf is full with EXTENT_DATA items, we must
+ * check the next one if that holds a reference as well.
+ * ref->count cannot be used to skip this check.
+ * repeat this until we don't find any additional EXTENT_DATA items.
+ */
+ while (1) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ return ret;
+ if (ret)
+ return 0;
+
+ eb = path->nodes[0];
+ for (slot = 0; slot < btrfs_header_nritems(eb); ++slot) {
+ btrfs_item_key_to_cpu(eb, &key, slot);
+ if (key.objectid != wanted_objectid ||
+ key.type != BTRFS_EXTENT_DATA_KEY)
+ return 0;
+ fi = btrfs_item_ptr(eb, slot,
+ struct btrfs_file_extent_item);
+ disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
+ if (disk_byte == wanted_disk_byte)
+ goto add_parent;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * resolve an indirect backref in the form (root_id, key, level)
+ * to a logical address
+ */
+static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
+ struct __prelim_ref *ref,
+ struct ulist *parents)
+{
+ struct btrfs_path *path;
+ struct btrfs_root *root;
+ struct btrfs_key root_key;
+ struct btrfs_key key = {0};
+ struct extent_buffer *eb;
+ int ret = 0;
+ int root_level;
+ int level = ref->level;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ root_key.objectid = ref->root_id;
+ root_key.type = BTRFS_ROOT_ITEM_KEY;
+ root_key.offset = (u64)-1;
+ root = btrfs_read_fs_root_no_name(fs_info, &root_key);
+ if (IS_ERR(root)) {
+ ret = PTR_ERR(root);
+ goto out;
+ }
+
+ rcu_read_lock();
+ root_level = btrfs_header_level(root->node);
+ rcu_read_unlock();
+
+ if (root_level + 1 == level)
+ goto out;
+
+ path->lowest_level = level;
+ ret = btrfs_search_slot(NULL, root, &ref->key, path, 0, 0);
+ pr_debug("search slot in root %llu (level %d, ref count %d) returned "
+ "%d for key (%llu %u %llu)\n",
+ (unsigned long long)ref->root_id, level, ref->count, ret,
+ (unsigned long long)ref->key.objectid, ref->key.type,
+ (unsigned long long)ref->key.offset);
+ if (ret < 0)
+ goto out;
+
+ eb = path->nodes[level];
+ if (!eb) {
+ WARN_ON(1);
+ ret = 1;
+ goto out;
+ }
+
+ if (level == 0) {
+ if (ret == 1 && path->slots[0] >= btrfs_header_nritems(eb)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret)
+ goto out;
+ eb = path->nodes[0];
+ }
+
+ btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
+ }
+
+ /* the last two parameters will only be used for level == 0 */
+ ret = add_all_parents(root, path, parents, eb, level, key.objectid,
+ ref->wanted_disk_byte);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * resolve all indirect backrefs from the list
+ */
+static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,
+ struct list_head *head)
+{
+ int err;
+ int ret = 0;
+ struct __prelim_ref *ref;
+ struct __prelim_ref *ref_safe;
+ struct __prelim_ref *new_ref;
+ struct ulist *parents;
+ struct ulist_node *node;
+
+ parents = ulist_alloc(GFP_NOFS);
+ if (!parents)
+ return -ENOMEM;
+
+ /*
+ * _safe allows us to insert directly after the current item without
+ * iterating over the newly inserted items.
+ * we're also allowed to re-assign ref during iteration.
+ */
+ list_for_each_entry_safe(ref, ref_safe, head, list) {
+ if (ref->parent) /* already direct */
+ continue;
+ if (ref->count == 0)
+ continue;
+ err = __resolve_indirect_ref(fs_info, ref, parents);
+ if (err) {
+ if (ret == 0)
+ ret = err;
+ continue;
+ }
+
+ /* we put the first parent into the ref at hand */
+ node = ulist_next(parents, NULL);
+ ref->parent = node ? node->val : 0;
+
+ /* additional parents require new refs being added here */
+ while ((node = ulist_next(parents, node))) {
+ new_ref = kmalloc(sizeof(*new_ref), GFP_NOFS);
+ if (!new_ref) {
+ ret = -ENOMEM;
+ break;
+ }
+ memcpy(new_ref, ref, sizeof(*ref));
+ new_ref->parent = node->val;
+ list_add(&new_ref->list, &ref->list);
+ }
+ ulist_reinit(parents);
+ }
+
+ ulist_free(parents);
+ return ret;
+}
+
+/*
+ * merge two lists of backrefs and adjust counts accordingly
+ *
+ * mode = 1: merge identical keys, if key is set
+ * mode = 2: merge identical parents
+ */
+static int __merge_refs(struct list_head *head, int mode)
+{
+ struct list_head *pos1;
+
+ list_for_each(pos1, head) {
+ struct list_head *n2;
+ struct list_head *pos2;
+ struct __prelim_ref *ref1;
+
+ ref1 = list_entry(pos1, struct __prelim_ref, list);
+
+ if (mode == 1 && ref1->key.type == 0)
+ continue;
+ for (pos2 = pos1->next, n2 = pos2->next; pos2 != head;
+ pos2 = n2, n2 = pos2->next) {
+ struct __prelim_ref *ref2;
+
+ ref2 = list_entry(pos2, struct __prelim_ref, list);
+
+ if (mode == 1) {
+ if (memcmp(&ref1->key, &ref2->key,
+ sizeof(ref1->key)) ||
+ ref1->level != ref2->level ||
+ ref1->root_id != ref2->root_id)
+ continue;
+ ref1->count += ref2->count;
+ } else {
+ if (ref1->parent != ref2->parent)
+ continue;
+ ref1->count += ref2->count;
+ }
+ list_del(&ref2->list);
+ kfree(ref2);
+ }
+
+ }
+ return 0;
+}
+
+/*
+ * add all currently queued delayed refs from this head whose seq nr is
+ * smaller or equal that seq to the list
+ */
+static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq,
+ struct btrfs_key *info_key,
+ struct list_head *prefs)
+{
+ struct btrfs_delayed_extent_op *extent_op = head->extent_op;
+ struct rb_node *n = &head->node.rb_node;
+ int sgn;
+ int ret;
+
+ if (extent_op && extent_op->update_key)
+ btrfs_disk_key_to_cpu(info_key, &extent_op->key);
+
+ while ((n = rb_prev(n))) {
+ struct btrfs_delayed_ref_node *node;
+ node = rb_entry(n, struct btrfs_delayed_ref_node,
+ rb_node);
+ if (node->bytenr != head->node.bytenr)
+ break;
+ WARN_ON(node->is_head);
+
+ if (node->seq > seq)
+ continue;
+
+ switch (node->action) {
+ case BTRFS_ADD_DELAYED_EXTENT:
+ case BTRFS_UPDATE_DELAYED_HEAD:
+ WARN_ON(1);
+ continue;
+ case BTRFS_ADD_DELAYED_REF:
+ sgn = 1;
+ break;
+ case BTRFS_DROP_DELAYED_REF:
+ sgn = -1;
+ break;
+ default:
+ BUG_ON(1);
+ }
+ switch (node->type) {
+ case BTRFS_TREE_BLOCK_REF_KEY: {
+ struct btrfs_delayed_tree_ref *ref;
+
+ ref = btrfs_delayed_node_to_tree_ref(node);
+ ret = __add_prelim_ref(prefs, ref->root, info_key,
+ ref->level + 1, 0, node->bytenr,
+ node->ref_mod * sgn);
+ break;
+ }
+ case BTRFS_SHARED_BLOCK_REF_KEY: {
+ struct btrfs_delayed_tree_ref *ref;
+
+ ref = btrfs_delayed_node_to_tree_ref(node);
+ ret = __add_prelim_ref(prefs, ref->root, info_key,
+ ref->level + 1, ref->parent,
+ node->bytenr,
+ node->ref_mod * sgn);
+ break;
+ }
+ case BTRFS_EXTENT_DATA_REF_KEY: {
+ struct btrfs_delayed_data_ref *ref;
+ struct btrfs_key key;
+
+ ref = btrfs_delayed_node_to_data_ref(node);
+
+ key.objectid = ref->objectid;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = ref->offset;
+ ret = __add_prelim_ref(prefs, ref->root, &key, 0, 0,
+ node->bytenr,
+ node->ref_mod * sgn);
+ break;
+ }
+ case BTRFS_SHARED_DATA_REF_KEY: {
+ struct btrfs_delayed_data_ref *ref;
+ struct btrfs_key key;
+
+ ref = btrfs_delayed_node_to_data_ref(node);
+
+ key.objectid = ref->objectid;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = ref->offset;
+ ret = __add_prelim_ref(prefs, ref->root, &key, 0,
+ ref->parent, node->bytenr,
+ node->ref_mod * sgn);
+ break;
+ }
+ default:
+ WARN_ON(1);
+ }
+ BUG_ON(ret);
+ }
+
+ return 0;
+}
+
+/*
+ * add all inline backrefs for bytenr to the list
+ */
+static int __add_inline_refs(struct btrfs_fs_info *fs_info,
+ struct btrfs_path *path, u64 bytenr,
+ struct btrfs_key *info_key, int *info_level,
+ struct list_head *prefs)
+{
+ int ret;
+ int slot;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+ unsigned long ptr;
+ unsigned long end;
+ struct btrfs_extent_item *ei;
+ u64 flags;
+ u64 item_size;
+
+ /*
+ * enumerate all inline refs
+ */
+ leaf = path->nodes[0];
+ slot = path->slots[0] - 1;
+
+ item_size = btrfs_item_size_nr(leaf, slot);
+ BUG_ON(item_size < sizeof(*ei));
+
+ ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
+ flags = btrfs_extent_flags(leaf, ei);
+
+ ptr = (unsigned long)(ei + 1);
+ end = (unsigned long)ei + item_size;
+
+ if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
+ struct btrfs_tree_block_info *info;
+ struct btrfs_disk_key disk_key;
+
+ info = (struct btrfs_tree_block_info *)ptr;
+ *info_level = btrfs_tree_block_level(leaf, info);
+ btrfs_tree_block_key(leaf, info, &disk_key);
+ btrfs_disk_key_to_cpu(info_key, &disk_key);
+ ptr += sizeof(struct btrfs_tree_block_info);
+ BUG_ON(ptr > end);
+ } else {
+ BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA));
+ }
+
+ while (ptr < end) {
+ struct btrfs_extent_inline_ref *iref;
+ u64 offset;
+ int type;
+
+ iref = (struct btrfs_extent_inline_ref *)ptr;
+ type = btrfs_extent_inline_ref_type(leaf, iref);
+ offset = btrfs_extent_inline_ref_offset(leaf, iref);
+
+ switch (type) {
+ case BTRFS_SHARED_BLOCK_REF_KEY:
+ ret = __add_prelim_ref(prefs, 0, info_key,
+ *info_level + 1, offset,
+ bytenr, 1);
+ break;
+ case BTRFS_SHARED_DATA_REF_KEY: {
+ struct btrfs_shared_data_ref *sdref;
+ int count;
+
+ sdref = (struct btrfs_shared_data_ref *)(iref + 1);
+ count = btrfs_shared_data_ref_count(leaf, sdref);
+ ret = __add_prelim_ref(prefs, 0, NULL, 0, offset,
+ bytenr, count);
+ break;
+ }
+ case BTRFS_TREE_BLOCK_REF_KEY:
+ ret = __add_prelim_ref(prefs, offset, info_key,
+ *info_level + 1, 0, bytenr, 1);
+ break;
+ case BTRFS_EXTENT_DATA_REF_KEY: {
+ struct btrfs_extent_data_ref *dref;
+ int count;
+ u64 root;
+
+ dref = (struct btrfs_extent_data_ref *)(&iref->offset);
+ count = btrfs_extent_data_ref_count(leaf, dref);
+ key.objectid = btrfs_extent_data_ref_objectid(leaf,
+ dref);
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = btrfs_extent_data_ref_offset(leaf, dref);
+ root = btrfs_extent_data_ref_root(leaf, dref);
+ ret = __add_prelim_ref(prefs, root, &key, 0, 0, bytenr,
+ count);
+ break;
+ }
+ default:
+ WARN_ON(1);
+ }
+ BUG_ON(ret);
+ ptr += btrfs_extent_inline_ref_size(type);
+ }
+
+ return 0;
+}
+
+/*
+ * add all non-inline backrefs for bytenr to the list
+ */
+static int __add_keyed_refs(struct btrfs_fs_info *fs_info,
+ struct btrfs_path *path, u64 bytenr,
+ struct btrfs_key *info_key, int info_level,
+ struct list_head *prefs)
+{
+ struct btrfs_root *extent_root = fs_info->extent_root;
+ int ret;
+ int slot;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+
+ while (1) {
+ ret = btrfs_next_item(extent_root, path);
+ if (ret < 0)
+ break;
+ if (ret) {
+ ret = 0;
+ break;
+ }
+
+ slot = path->slots[0];
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+
+ if (key.objectid != bytenr)
+ break;
+ if (key.type < BTRFS_TREE_BLOCK_REF_KEY)
+ continue;
+ if (key.type > BTRFS_SHARED_DATA_REF_KEY)
+ break;
+
+ switch (key.type) {
+ case BTRFS_SHARED_BLOCK_REF_KEY:
+ ret = __add_prelim_ref(prefs, 0, info_key,
+ info_level + 1, key.offset,
+ bytenr, 1);
+ break;
+ case BTRFS_SHARED_DATA_REF_KEY: {
+ struct btrfs_shared_data_ref *sdref;
+ int count;
+
+ sdref = btrfs_item_ptr(leaf, slot,
+ struct btrfs_shared_data_ref);
+ count = btrfs_shared_data_ref_count(leaf, sdref);
+ ret = __add_prelim_ref(prefs, 0, NULL, 0, key.offset,
+ bytenr, count);
+ break;
+ }
+ case BTRFS_TREE_BLOCK_REF_KEY:
+ ret = __add_prelim_ref(prefs, key.offset, info_key,
+ info_level + 1, 0, bytenr, 1);
+ break;
+ case BTRFS_EXTENT_DATA_REF_KEY: {
+ struct btrfs_extent_data_ref *dref;
+ int count;
+ u64 root;
+
+ dref = btrfs_item_ptr(leaf, slot,
+ struct btrfs_extent_data_ref);
+ count = btrfs_extent_data_ref_count(leaf, dref);
+ key.objectid = btrfs_extent_data_ref_objectid(leaf,
+ dref);
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = btrfs_extent_data_ref_offset(leaf, dref);
+ root = btrfs_extent_data_ref_root(leaf, dref);
+ ret = __add_prelim_ref(prefs, root, &key, 0, 0,
+ bytenr, count);
+ break;
+ }
+ default:
+ WARN_ON(1);
+ }
+ BUG_ON(ret);
+ }
+
+ return ret;
+}
+
+/*
+ * this adds all existing backrefs (inline backrefs, backrefs and delayed
+ * refs) for the given bytenr to the refs list, merges duplicates and resolves
+ * indirect refs to their parent bytenr.
+ * When roots are found, they're added to the roots list
+ *
+ * FIXME some caching might speed things up
+ */
+static int find_parent_nodes(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info, u64 bytenr,
+ u64 seq, struct ulist *refs, struct ulist *roots)
+{
+ struct btrfs_key key;
+ struct btrfs_path *path;
+ struct btrfs_key info_key = { 0 };
+ struct btrfs_delayed_ref_root *delayed_refs = NULL;
+ struct btrfs_delayed_ref_head *head = NULL;
+ int info_level = 0;
+ int ret;
+ struct list_head prefs_delayed;
+ struct list_head prefs;
+ struct __prelim_ref *ref;
+
+ INIT_LIST_HEAD(&prefs);
+ INIT_LIST_HEAD(&prefs_delayed);
+
+ key.objectid = bytenr;
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ key.offset = (u64)-1;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ /*
+ * grab both a lock on the path and a lock on the delayed ref head.
+ * We need both to get a consistent picture of how the refs look
+ * at a specified point in time
+ */
+again:
+ ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+ BUG_ON(ret == 0);
+
+ /*
+ * look if there are updates for this ref queued and lock the head
+ */
+ delayed_refs = &trans->transaction->delayed_refs;
+ spin_lock(&delayed_refs->lock);
+ head = btrfs_find_delayed_ref_head(trans, bytenr);
+ if (head) {
+ if (!mutex_trylock(&head->mutex)) {
+ atomic_inc(&head->node.refs);
+ spin_unlock(&delayed_refs->lock);
+
+ btrfs_release_path(path);
+
+ /*
+ * Mutex was contended, block until it's
+ * released and try again
+ */
+ mutex_lock(&head->mutex);
+ mutex_unlock(&head->mutex);
+ btrfs_put_delayed_ref(&head->node);
+ goto again;
+ }
+ ret = __add_delayed_refs(head, seq, &info_key, &prefs_delayed);
+ if (ret)
+ goto out;
+ }
+ spin_unlock(&delayed_refs->lock);
+
+ if (path->slots[0]) {
+ struct extent_buffer *leaf;
+ int slot;
+
+ leaf = path->nodes[0];
+ slot = path->slots[0] - 1;
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ if (key.objectid == bytenr &&
+ key.type == BTRFS_EXTENT_ITEM_KEY) {
+ ret = __add_inline_refs(fs_info, path, bytenr,
+ &info_key, &info_level, &prefs);
+ if (ret)
+ goto out;
+ ret = __add_keyed_refs(fs_info, path, bytenr, &info_key,
+ info_level, &prefs);
+ if (ret)
+ goto out;
+ }
+ }
+ btrfs_release_path(path);
+
+ /*
+ * when adding the delayed refs above, the info_key might not have
+ * been known yet. Go over the list and replace the missing keys
+ */
+ list_for_each_entry(ref, &prefs_delayed, list) {
+ if ((ref->key.offset | ref->key.type | ref->key.objectid) == 0)
+ memcpy(&ref->key, &info_key, sizeof(ref->key));
+ }
+ list_splice_init(&prefs_delayed, &prefs);
+
+ ret = __merge_refs(&prefs, 1);
+ if (ret)
+ goto out;
+
+ ret = __resolve_indirect_refs(fs_info, &prefs);
+ if (ret)
+ goto out;
+
+ ret = __merge_refs(&prefs, 2);
+ if (ret)
+ goto out;
+
+ while (!list_empty(&prefs)) {
+ ref = list_first_entry(&prefs, struct __prelim_ref, list);
+ list_del(&ref->list);
+ if (ref->count < 0)
+ WARN_ON(1);
+ if (ref->count && ref->root_id && ref->parent == 0) {
+ /* no parent == root of tree */
+ ret = ulist_add(roots, ref->root_id, 0, GFP_NOFS);
+ BUG_ON(ret < 0);
+ }
+ if (ref->count && ref->parent) {
+ ret = ulist_add(refs, ref->parent, 0, GFP_NOFS);
+ BUG_ON(ret < 0);
+ }
+ kfree(ref);
+ }
+
+out:
+ if (head)
+ mutex_unlock(&head->mutex);
+ btrfs_free_path(path);
+ while (!list_empty(&prefs)) {
+ ref = list_first_entry(&prefs, struct __prelim_ref, list);
+ list_del(&ref->list);
+ kfree(ref);
+ }
+ while (!list_empty(&prefs_delayed)) {
+ ref = list_first_entry(&prefs_delayed, struct __prelim_ref,
+ list);
+ list_del(&ref->list);
+ kfree(ref);
+ }
+
+ return ret;
+}
+
+/*
+ * Finds all leafs with a reference to the specified combination of bytenr and
+ * offset. key_list_head will point to a list of corresponding keys (caller must
+ * free each list element). The leafs will be stored in the leafs ulist, which
+ * must be freed with ulist_free.
+ *
+ * returns 0 on success, <0 on error
+ */
+static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info, u64 bytenr,
+ u64 num_bytes, u64 seq, struct ulist **leafs)
+{
+ struct ulist *tmp;
+ int ret;
+
+ tmp = ulist_alloc(GFP_NOFS);
+ if (!tmp)
+ return -ENOMEM;
+ *leafs = ulist_alloc(GFP_NOFS);
+ if (!*leafs) {
+ ulist_free(tmp);
+ return -ENOMEM;
+ }
+
+ ret = find_parent_nodes(trans, fs_info, bytenr, seq, *leafs, tmp);
+ ulist_free(tmp);
+
+ if (ret < 0 && ret != -ENOENT) {
+ ulist_free(*leafs);
+ return ret;
+ }
+
+ return 0;
+}
+
+/*
+ * walk all backrefs for a given extent to find all roots that reference this
+ * extent. Walking a backref means finding all extents that reference this
+ * extent and in turn walk the backrefs of those, too. Naturally this is a
+ * recursive process, but here it is implemented in an iterative fashion: We
+ * find all referencing extents for the extent in question and put them on a
+ * list. In turn, we find all referencing extents for those, further appending
+ * to the list. The way we iterate the list allows adding more elements after
+ * the current while iterating. The process stops when we reach the end of the
+ * list. Found roots are added to the roots list.
+ *
+ * returns 0 on success, < 0 on error.
+ */
+int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info, u64 bytenr,
+ u64 num_bytes, u64 seq, struct ulist **roots)
+{
+ struct ulist *tmp;
+ struct ulist_node *node = NULL;
+ int ret;
+
+ tmp = ulist_alloc(GFP_NOFS);
+ if (!tmp)
+ return -ENOMEM;
+ *roots = ulist_alloc(GFP_NOFS);
+ if (!*roots) {
+ ulist_free(tmp);
+ return -ENOMEM;
+ }
+
+ while (1) {
+ ret = find_parent_nodes(trans, fs_info, bytenr, seq,
+ tmp, *roots);
+ if (ret < 0 && ret != -ENOENT) {
+ ulist_free(tmp);
+ ulist_free(*roots);
+ return ret;
+ }
+ node = ulist_next(tmp, node);
+ if (!node)
+ break;
+ bytenr = node->val;
+ }
+
+ ulist_free(tmp);
+ return 0;
+}
+
+
static int __inode_info(u64 inum, u64 ioff, u8 key_type,
struct btrfs_root *fs_root, struct btrfs_path *path,
struct btrfs_key *found_key)
projects / platform / kernel / linux-rpi.git / commitdiff