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-rw-r--r--fs/btrfs/backref.c103
1 files changed, 65 insertions, 38 deletions
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 6b8824de2abb..a1eb573fbb10 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -136,6 +136,7 @@ struct share_check {
u64 root_objectid;
u64 inum;
int share_count;
+ bool have_delayed_delete_refs;
};
static inline int extent_is_shared(struct share_check *sc)
@@ -588,6 +589,18 @@ unode_aux_to_inode_list(struct ulist_node *node)
return (struct extent_inode_elem *)(uintptr_t)node->aux;
}
+static void free_leaf_list(struct ulist *ulist)
+{
+ struct ulist_node *node;
+ struct ulist_iterator uiter;
+
+ ULIST_ITER_INIT(&uiter);
+ while ((node = ulist_next(ulist, &uiter)))
+ free_inode_elem_list(unode_aux_to_inode_list(node));
+
+ ulist_free(ulist);
+}
+
/*
* We maintain three seperate rbtrees: one for direct refs, one for
* indirect refs which have a key, and one for indirect refs which do not
@@ -702,7 +715,11 @@ static int resolve_indirect_refs(struct btrfs_fs_info *fs_info,
cond_resched();
}
out:
- ulist_free(parents);
+ /*
+ * We may have inode lists attached to refs in the parents ulist, so we
+ * must free them before freeing the ulist and its refs.
+ */
+ free_leaf_list(parents);
return ret;
}
@@ -760,16 +777,11 @@ static int add_delayed_refs(const struct btrfs_fs_info *fs_info,
struct share_check *sc)
{
struct btrfs_delayed_ref_node *node;
- struct btrfs_delayed_extent_op *extent_op = head->extent_op;
struct btrfs_key key;
- struct btrfs_key tmp_op_key;
struct rb_node *n;
int count;
int ret = 0;
- if (extent_op && extent_op->update_key)
- btrfs_disk_key_to_cpu(&tmp_op_key, &extent_op->key);
-
spin_lock(&head->lock);
for (n = rb_first(&head->ref_tree); n; n = rb_next(n)) {
node = rb_entry(n, struct btrfs_delayed_ref_node,
@@ -796,10 +808,16 @@ static int add_delayed_refs(const struct btrfs_fs_info *fs_info,
case BTRFS_TREE_BLOCK_REF_KEY: {
/* NORMAL INDIRECT METADATA backref */
struct btrfs_delayed_tree_ref *ref;
+ struct btrfs_key *key_ptr = NULL;
+
+ if (head->extent_op && head->extent_op->update_key) {
+ btrfs_disk_key_to_cpu(&key, &head->extent_op->key);
+ key_ptr = &key;
+ }
ref = btrfs_delayed_node_to_tree_ref(node);
ret = add_indirect_ref(fs_info, preftrees, ref->root,
- &tmp_op_key, ref->level + 1,
+ key_ptr, ref->level + 1,
node->bytenr, count, sc,
GFP_ATOMIC);
break;
@@ -825,13 +843,22 @@ static int add_delayed_refs(const struct btrfs_fs_info *fs_info,
key.offset = ref->offset;
/*
- * Found a inum that doesn't match our known inum, we
- * know it's shared.
+ * If we have a share check context and a reference for
+ * another inode, we can't exit immediately. This is
+ * because even if this is a BTRFS_ADD_DELAYED_REF
+ * reference we may find next a BTRFS_DROP_DELAYED_REF
+ * which cancels out this ADD reference.
+ *
+ * If this is a DROP reference and there was no previous
+ * ADD reference, then we need to signal that when we
+ * process references from the extent tree (through
+ * add_inline_refs() and add_keyed_refs()), we should
+ * not exit early if we find a reference for another
+ * inode, because one of the delayed DROP references
+ * may cancel that reference in the extent tree.
*/
- if (sc && sc->inum && ref->objectid != sc->inum) {
- ret = BACKREF_FOUND_SHARED;
- goto out;
- }
+ if (sc && count < 0)
+ sc->have_delayed_delete_refs = true;
ret = add_indirect_ref(fs_info, preftrees, ref->root,
&key, 0, node->bytenr, count, sc,
@@ -861,7 +888,7 @@ static int add_delayed_refs(const struct btrfs_fs_info *fs_info,
}
if (!ret)
ret = extent_is_shared(sc);
-out:
+
spin_unlock(&head->lock);
return ret;
}
@@ -965,7 +992,8 @@ static int add_inline_refs(const struct btrfs_fs_info *fs_info,
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = btrfs_extent_data_ref_offset(leaf, dref);
- if (sc && sc->inum && key.objectid != sc->inum) {
+ if (sc && sc->inum && key.objectid != sc->inum &&
+ !sc->have_delayed_delete_refs) {
ret = BACKREF_FOUND_SHARED;
break;
}
@@ -975,6 +1003,7 @@ static int add_inline_refs(const struct btrfs_fs_info *fs_info,
ret = add_indirect_ref(fs_info, preftrees, root,
&key, 0, bytenr, count,
sc, GFP_NOFS);
+
break;
}
default:
@@ -1064,7 +1093,8 @@ static int add_keyed_refs(struct btrfs_fs_info *fs_info,
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = btrfs_extent_data_ref_offset(leaf, dref);
- if (sc && sc->inum && key.objectid != sc->inum) {
+ if (sc && sc->inum && key.objectid != sc->inum &&
+ !sc->have_delayed_delete_refs) {
ret = BACKREF_FOUND_SHARED;
break;
}
@@ -1160,7 +1190,12 @@ again:
ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0);
if (ret < 0)
goto out;
- BUG_ON(ret == 0);
+ if (ret == 0) {
+ /* This shouldn't happen, indicates a bug or fs corruption. */
+ ASSERT(ret != 0);
+ ret = -EUCLEAN;
+ goto out;
+ }
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
if (trans && likely(trans->type != __TRANS_DUMMY) &&
@@ -1308,10 +1343,18 @@ again:
goto out;
if (!ret && extent_item_pos) {
/*
- * we've recorded that parent, so we must extend
- * its inode list here
+ * We've recorded that parent, so we must extend
+ * its inode list here.
+ *
+ * However if there was corruption we may not
+ * have found an eie, return an error in this
+ * case.
*/
- BUG_ON(!eie);
+ ASSERT(eie);
+ if (!eie) {
+ ret = -EUCLEAN;
+ goto out;
+ }
while (eie->next)
eie = eie->next;
eie->next = ref->inode_list;
@@ -1333,24 +1376,6 @@ out:
return ret;
}
-static void free_leaf_list(struct ulist *blocks)
-{
- struct ulist_node *node = NULL;
- struct extent_inode_elem *eie;
- struct ulist_iterator uiter;
-
- ULIST_ITER_INIT(&uiter);
- while ((node = ulist_next(blocks, &uiter))) {
- if (!node->aux)
- continue;
- eie = unode_aux_to_inode_list(node);
- free_inode_elem_list(eie);
- node->aux = 0;
- }
-
- ulist_free(blocks);
-}
-
/*
* 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
@@ -1477,6 +1502,7 @@ int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr)
.root_objectid = root->objectid,
.inum = inum,
.share_count = 0,
+ .have_delayed_delete_refs = false,
};
tmp = ulist_alloc(GFP_NOFS);
@@ -1515,6 +1541,7 @@ int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr)
break;
bytenr = node->val;
shared.share_count = 0;
+ shared.have_delayed_delete_refs = false;
cond_resched();
}
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-05-01 05:58:26 +0000