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-rw-r--r--fs/btrfs/backref.c1085
1 files changed, 480 insertions, 605 deletions
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index f723c11bb763..b517ef1477ea 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -18,6 +18,7 @@
#include <linux/mm.h>
#include <linux/rbtree.h>
+#include <trace/events/btrfs.h>
#include "ctree.h"
#include "disk-io.h"
#include "backref.h"
@@ -26,11 +27,6 @@
#include "delayed-ref.h"
#include "locking.h"
-enum merge_mode {
- MERGE_IDENTICAL_KEYS = 1,
- MERGE_IDENTICAL_PARENTS,
-};
-
/* Just an arbitrary number so we can be sure this happened */
#define BACKREF_FOUND_SHARED 6
@@ -40,269 +36,11 @@ struct extent_inode_elem {
struct extent_inode_elem *next;
};
-/*
- * ref_root is used as the root of the ref tree that hold a collection
- * of unique references.
- */
-struct ref_root {
- struct rb_root rb_root;
-
- /*
- * The unique_refs represents the number of ref_nodes with a positive
- * count stored in the tree. Even if a ref_node (the count is greater
- * than one) is added, the unique_refs will only increase by one.
- */
- unsigned int unique_refs;
-};
-
-/* ref_node is used to store a unique reference to the ref tree. */
-struct ref_node {
- struct rb_node rb_node;
-
- /* For NORMAL_REF, otherwise all these fields should be set to 0 */
- u64 root_id;
- u64 object_id;
- u64 offset;
-
- /* For SHARED_REF, otherwise parent field should be set to 0 */
- u64 parent;
-
- /* Ref to the ref_mod of btrfs_delayed_ref_node */
- int ref_mod;
-};
-
-/* Dynamically allocate and initialize a ref_root */
-static struct ref_root *ref_root_alloc(void)
-{
- struct ref_root *ref_tree;
-
- ref_tree = kmalloc(sizeof(*ref_tree), GFP_NOFS);
- if (!ref_tree)
- return NULL;
-
- ref_tree->rb_root = RB_ROOT;
- ref_tree->unique_refs = 0;
-
- return ref_tree;
-}
-
-/* Free all nodes in the ref tree, and reinit ref_root */
-static void ref_root_fini(struct ref_root *ref_tree)
-{
- struct ref_node *node;
- struct rb_node *next;
-
- while ((next = rb_first(&ref_tree->rb_root)) != NULL) {
- node = rb_entry(next, struct ref_node, rb_node);
- rb_erase(next, &ref_tree->rb_root);
- kfree(node);
- }
-
- ref_tree->rb_root = RB_ROOT;
- ref_tree->unique_refs = 0;
-}
-
-static void ref_root_free(struct ref_root *ref_tree)
-{
- if (!ref_tree)
- return;
-
- ref_root_fini(ref_tree);
- kfree(ref_tree);
-}
-
-/*
- * Compare ref_node with (root_id, object_id, offset, parent)
- *
- * The function compares two ref_node a and b. It returns an integer less
- * than, equal to, or greater than zero , respectively, to be less than, to
- * equal, or be greater than b.
- */
-static int ref_node_cmp(struct ref_node *a, struct ref_node *b)
-{
- if (a->root_id < b->root_id)
- return -1;
- else if (a->root_id > b->root_id)
- return 1;
-
- if (a->object_id < b->object_id)
- return -1;
- else if (a->object_id > b->object_id)
- return 1;
-
- if (a->offset < b->offset)
- return -1;
- else if (a->offset > b->offset)
- return 1;
-
- if (a->parent < b->parent)
- return -1;
- else if (a->parent > b->parent)
- return 1;
-
- return 0;
-}
-
-/*
- * Search ref_node with (root_id, object_id, offset, parent) in the tree
- *
- * if found, the pointer of the ref_node will be returned;
- * if not found, NULL will be returned and pos will point to the rb_node for
- * insert, pos_parent will point to pos'parent for insert;
-*/
-static struct ref_node *__ref_tree_search(struct ref_root *ref_tree,
- struct rb_node ***pos,
- struct rb_node **pos_parent,
- u64 root_id, u64 object_id,
- u64 offset, u64 parent)
-{
- struct ref_node *cur = NULL;
- struct ref_node entry;
- int ret;
-
- entry.root_id = root_id;
- entry.object_id = object_id;
- entry.offset = offset;
- entry.parent = parent;
-
- *pos = &ref_tree->rb_root.rb_node;
-
- while (**pos) {
- *pos_parent = **pos;
- cur = rb_entry(*pos_parent, struct ref_node, rb_node);
-
- ret = ref_node_cmp(cur, &entry);
- if (ret > 0)
- *pos = &(**pos)->rb_left;
- else if (ret < 0)
- *pos = &(**pos)->rb_right;
- else
- return cur;
- }
-
- return NULL;
-}
-
-/*
- * Insert a ref_node to the ref tree
- * @pos used for specifiy the position to insert
- * @pos_parent for specifiy pos's parent
- *
- * success, return 0;
- * ref_node already exists, return -EEXIST;
-*/
-static int ref_tree_insert(struct ref_root *ref_tree, struct rb_node **pos,
- struct rb_node *pos_parent, struct ref_node *ins)
-{
- struct rb_node **p = NULL;
- struct rb_node *parent = NULL;
- struct ref_node *cur = NULL;
-
- if (!pos) {
- cur = __ref_tree_search(ref_tree, &p, &parent, ins->root_id,
- ins->object_id, ins->offset,
- ins->parent);
- if (cur)
- return -EEXIST;
- } else {
- p = pos;
- parent = pos_parent;
- }
-
- rb_link_node(&ins->rb_node, parent, p);
- rb_insert_color(&ins->rb_node, &ref_tree->rb_root);
-
- return 0;
-}
-
-/* Erase and free ref_node, caller should update ref_root->unique_refs */
-static void ref_tree_remove(struct ref_root *ref_tree, struct ref_node *node)
-{
- rb_erase(&node->rb_node, &ref_tree->rb_root);
- kfree(node);
-}
-
-/*
- * Update ref_root->unique_refs
- *
- * Call __ref_tree_search
- * 1. if ref_node doesn't exist, ref_tree_insert this node, and update
- * ref_root->unique_refs:
- * if ref_node->ref_mod > 0, ref_root->unique_refs++;
- * if ref_node->ref_mod < 0, do noting;
- *
- * 2. if ref_node is found, then get origin ref_node->ref_mod, and update
- * ref_node->ref_mod.
- * if ref_node->ref_mod is equal to 0,then call ref_tree_remove
- *
- * according to origin_mod and new_mod, update ref_root->items
- * +----------------+--------------+-------------+
- * | |new_count <= 0|new_count > 0|
- * +----------------+--------------+-------------+
- * |origin_count < 0| 0 | 1 |
- * +----------------+--------------+-------------+
- * |origin_count > 0| -1 | 0 |
- * +----------------+--------------+-------------+
- *
- * In case of allocation failure, -ENOMEM is returned and the ref_tree stays
- * unaltered.
- * Success, return 0
- */
-static int ref_tree_add(struct ref_root *ref_tree, u64 root_id, u64 object_id,
- u64 offset, u64 parent, int count)
-{
- struct ref_node *node = NULL;
- struct rb_node **pos = NULL;
- struct rb_node *pos_parent = NULL;
- int origin_count;
- int ret;
-
- if (!count)
- return 0;
-
- node = __ref_tree_search(ref_tree, &pos, &pos_parent, root_id,
- object_id, offset, parent);
- if (node == NULL) {
- node = kmalloc(sizeof(*node), GFP_NOFS);
- if (!node)
- return -ENOMEM;
-
- node->root_id = root_id;
- node->object_id = object_id;
- node->offset = offset;
- node->parent = parent;
- node->ref_mod = count;
-
- ret = ref_tree_insert(ref_tree, pos, pos_parent, node);
- ASSERT(!ret);
- if (ret) {
- kfree(node);
- return ret;
- }
-
- ref_tree->unique_refs += node->ref_mod > 0 ? 1 : 0;
-
- return 0;
- }
-
- origin_count = node->ref_mod;
- node->ref_mod += count;
-
- if (node->ref_mod > 0)
- ref_tree->unique_refs += origin_count > 0 ? 0 : 1;
- else if (node->ref_mod <= 0)
- ref_tree->unique_refs += origin_count > 0 ? -1 : 0;
-
- if (!node->ref_mod)
- ref_tree_remove(ref_tree, node);
-
- return 0;
-}
-
-static int check_extent_in_eb(struct btrfs_key *key, struct extent_buffer *eb,
- struct btrfs_file_extent_item *fi,
- u64 extent_item_pos,
- struct extent_inode_elem **eie)
+static int check_extent_in_eb(const struct btrfs_key *key,
+ const struct extent_buffer *eb,
+ const struct btrfs_file_extent_item *fi,
+ u64 extent_item_pos,
+ struct extent_inode_elem **eie)
{
u64 offset = 0;
struct extent_inode_elem *e;
@@ -344,9 +82,9 @@ static void free_inode_elem_list(struct extent_inode_elem *eie)
}
}
-static int find_extent_in_eb(struct extent_buffer *eb, u64 wanted_disk_byte,
- u64 extent_item_pos,
- struct extent_inode_elem **eie)
+static int find_extent_in_eb(const struct extent_buffer *eb,
+ u64 wanted_disk_byte, u64 extent_item_pos,
+ struct extent_inode_elem **eie)
{
u64 disk_byte;
struct btrfs_key key;
@@ -383,26 +121,44 @@ static int find_extent_in_eb(struct extent_buffer *eb, u64 wanted_disk_byte,
return 0;
}
+struct preftree {
+ struct rb_root root;
+ unsigned int count;
+};
+
+#define PREFTREE_INIT { .root = RB_ROOT, .count = 0 }
+
+struct preftrees {
+ struct preftree direct; /* BTRFS_SHARED_[DATA|BLOCK]_REF_KEY */
+ struct preftree indirect; /* BTRFS_[TREE_BLOCK|EXTENT_DATA]_REF_KEY */
+ struct preftree indirect_missing_keys;
+};
+
/*
- * this structure records all encountered refs on the way up to the root
+ * Checks for a shared extent during backref search.
+ *
+ * The share_count tracks prelim_refs (direct and indirect) having a
+ * ref->count >0:
+ * - incremented when a ref->count transitions to >0
+ * - decremented when a ref->count transitions to <1
*/
-struct __prelim_ref {
- struct list_head list;
- u64 root_id;
- struct btrfs_key key_for_search;
- int level;
- int count;
- struct extent_inode_elem *inode_list;
- u64 parent;
- u64 wanted_disk_byte;
+struct share_check {
+ u64 root_objectid;
+ u64 inum;
+ int share_count;
};
+static inline int extent_is_shared(struct share_check *sc)
+{
+ return (sc && sc->share_count > 1) ? BACKREF_FOUND_SHARED : 0;
+}
+
static struct kmem_cache *btrfs_prelim_ref_cache;
int __init btrfs_prelim_ref_init(void)
{
btrfs_prelim_ref_cache = kmem_cache_create("btrfs_prelim_ref",
- sizeof(struct __prelim_ref),
+ sizeof(struct prelim_ref),
0,
SLAB_MEM_SPREAD,
NULL);
@@ -416,6 +172,134 @@ void btrfs_prelim_ref_exit(void)
kmem_cache_destroy(btrfs_prelim_ref_cache);
}
+static void free_pref(struct prelim_ref *ref)
+{
+ kmem_cache_free(btrfs_prelim_ref_cache, ref);
+}
+
+/*
+ * Return 0 when both refs are for the same block (and can be merged).
+ * A -1 return indicates ref1 is a 'lower' block than ref2, while 1
+ * indicates a 'higher' block.
+ */
+static int prelim_ref_compare(struct prelim_ref *ref1,
+ struct prelim_ref *ref2)
+{
+ if (ref1->level < ref2->level)
+ return -1;
+ if (ref1->level > ref2->level)
+ return 1;
+ if (ref1->root_id < ref2->root_id)
+ return -1;
+ if (ref1->root_id > ref2->root_id)
+ return 1;
+ if (ref1->key_for_search.type < ref2->key_for_search.type)
+ return -1;
+ if (ref1->key_for_search.type > ref2->key_for_search.type)
+ return 1;
+ if (ref1->key_for_search.objectid < ref2->key_for_search.objectid)
+ return -1;
+ if (ref1->key_for_search.objectid > ref2->key_for_search.objectid)
+ return 1;
+ if (ref1->key_for_search.offset < ref2->key_for_search.offset)
+ return -1;
+ if (ref1->key_for_search.offset > ref2->key_for_search.offset)
+ return 1;
+ if (ref1->parent < ref2->parent)
+ return -1;
+ if (ref1->parent > ref2->parent)
+ return 1;
+
+ return 0;
+}
+
+void update_share_count(struct share_check *sc, int oldcount, int newcount)
+{
+ if ((!sc) || (oldcount == 0 && newcount < 1))
+ return;
+
+ if (oldcount > 0 && newcount < 1)
+ sc->share_count--;
+ else if (oldcount < 1 && newcount > 0)
+ sc->share_count++;
+}
+
+/*
+ * Add @newref to the @root rbtree, merging identical refs.
+ *
+ * Callers should assume that newref has been freed after calling.
+ */
+static void prelim_ref_insert(const struct btrfs_fs_info *fs_info,
+ struct preftree *preftree,
+ struct prelim_ref *newref,
+ struct share_check *sc)
+{
+ struct rb_root *root;
+ struct rb_node **p;
+ struct rb_node *parent = NULL;
+ struct prelim_ref *ref;
+ int result;
+
+ root = &preftree->root;
+ p = &root->rb_node;
+
+ while (*p) {
+ parent = *p;
+ ref = rb_entry(parent, struct prelim_ref, rbnode);
+ result = prelim_ref_compare(ref, newref);
+ if (result < 0) {
+ p = &(*p)->rb_left;
+ } else if (result > 0) {
+ p = &(*p)->rb_right;
+ } else {
+ /* Identical refs, merge them and free @newref */
+ struct extent_inode_elem *eie = ref->inode_list;
+
+ while (eie && eie->next)
+ eie = eie->next;
+
+ if (!eie)
+ ref->inode_list = newref->inode_list;
+ else
+ eie->next = newref->inode_list;
+ trace_btrfs_prelim_ref_merge(fs_info, ref, newref,
+ preftree->count);
+ /*
+ * A delayed ref can have newref->count < 0.
+ * The ref->count is updated to follow any
+ * BTRFS_[ADD|DROP]_DELAYED_REF actions.
+ */
+ update_share_count(sc, ref->count,
+ ref->count + newref->count);
+ ref->count += newref->count;
+ free_pref(newref);
+ return;
+ }
+ }
+
+ update_share_count(sc, 0, newref->count);
+ preftree->count++;
+ trace_btrfs_prelim_ref_insert(fs_info, newref, NULL, preftree->count);
+ rb_link_node(&newref->rbnode, parent, p);
+ rb_insert_color(&newref->rbnode, root);
+}
+
+/*
+ * Release the entire tree. We don't care about internal consistency so
+ * just free everything and then reset the tree root.
+ */
+static void prelim_release(struct preftree *preftree)
+{
+ struct prelim_ref *ref, *next_ref;
+
+ rbtree_postorder_for_each_entry_safe(ref, next_ref, &preftree->root,
+ rbnode)
+ free_pref(ref);
+
+ preftree->root = RB_ROOT;
+ preftree->count = 0;
+}
+
/*
* the rules for all callers of this function are:
* - obtaining the parent is the goal
@@ -448,19 +332,19 @@ void btrfs_prelim_ref_exit(void)
*
* - column 1, 3: we've the parent -> done
* - column 2: we take the first key from the block to find the parent
- * (see __add_missing_keys)
+ * (see add_missing_keys)
* - column 4: we use the key to find the parent
*
* additional information that's available but not required to find the parent
* block might help in merging entries to gain some speed.
*/
-
-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,
- gfp_t gfp_mask)
+static int add_prelim_ref(const struct btrfs_fs_info *fs_info,
+ struct preftree *preftree, u64 root_id,
+ const struct btrfs_key *key, int level, u64 parent,
+ u64 wanted_disk_byte, int count,
+ struct share_check *sc, gfp_t gfp_mask)
{
- struct __prelim_ref *ref;
+ struct prelim_ref *ref;
if (root_id == BTRFS_DATA_RELOC_TREE_OBJECTID)
return 0;
@@ -503,13 +387,37 @@ static int __add_prelim_ref(struct list_head *head, u64 root_id,
ref->count = count;
ref->parent = parent;
ref->wanted_disk_byte = wanted_disk_byte;
- list_add_tail(&ref->list, head);
+ prelim_ref_insert(fs_info, preftree, ref, sc);
+ return extent_is_shared(sc);
+}
- return 0;
+/* direct refs use root == 0, key == NULL */
+static int add_direct_ref(const struct btrfs_fs_info *fs_info,
+ struct preftrees *preftrees, int level, u64 parent,
+ u64 wanted_disk_byte, int count,
+ struct share_check *sc, gfp_t gfp_mask)
+{
+ return add_prelim_ref(fs_info, &preftrees->direct, 0, NULL, level,
+ parent, wanted_disk_byte, count, sc, gfp_mask);
+}
+
+/* indirect refs use parent == 0 */
+static int add_indirect_ref(const struct btrfs_fs_info *fs_info,
+ struct preftrees *preftrees, u64 root_id,
+ const struct btrfs_key *key, int level,
+ u64 wanted_disk_byte, int count,
+ struct share_check *sc, gfp_t gfp_mask)
+{
+ struct preftree *tree = &preftrees->indirect;
+
+ if (!key)
+ tree = &preftrees->indirect_missing_keys;
+ return add_prelim_ref(fs_info, tree, root_id, key, level, 0,
+ wanted_disk_byte, count, sc, gfp_mask);
}
static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,
- struct ulist *parents, struct __prelim_ref *ref,
+ struct ulist *parents, struct prelim_ref *ref,
int level, u64 time_seq, const u64 *extent_item_pos,
u64 total_refs)
{
@@ -599,11 +507,10 @@ next:
* 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 btrfs_path *path, u64 time_seq,
- struct __prelim_ref *ref,
- struct ulist *parents,
- const u64 *extent_item_pos, u64 total_refs)
+static int resolve_indirect_ref(struct btrfs_fs_info *fs_info,
+ struct btrfs_path *path, u64 time_seq,
+ struct prelim_ref *ref, struct ulist *parents,
+ const u64 *extent_item_pos, u64 total_refs)
{
struct btrfs_root *root;
struct btrfs_key root_key;
@@ -681,52 +588,90 @@ out:
return ret;
}
+static struct extent_inode_elem *
+unode_aux_to_inode_list(struct ulist_node *node)
+{
+ if (!node)
+ return NULL;
+ return (struct extent_inode_elem *)(uintptr_t)node->aux;
+}
+
/*
- * resolve all indirect backrefs from the list
+ * 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
+ * have a key. Each tree does merge on insertion.
+ *
+ * Once all of the references are located, we iterate over the tree of
+ * indirect refs with missing keys. An appropriate key is located and
+ * the ref is moved onto the tree for indirect refs. After all missing
+ * keys are thus located, we iterate over the indirect ref tree, resolve
+ * each reference, and then insert the resolved reference onto the
+ * direct tree (merging there too).
+ *
+ * New backrefs (i.e., for parent nodes) are added to the appropriate
+ * rbtree as they are encountered. The new backrefs are subsequently
+ * resolved as above.
*/
-static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,
- struct btrfs_path *path, u64 time_seq,
- struct list_head *head,
- const u64 *extent_item_pos, u64 total_refs,
- u64 root_objectid)
+static int resolve_indirect_refs(struct btrfs_fs_info *fs_info,
+ struct btrfs_path *path, u64 time_seq,
+ struct preftrees *preftrees,
+ const u64 *extent_item_pos, u64 total_refs,
+ struct share_check *sc)
{
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;
struct ulist_iterator uiter;
+ struct rb_node *rnode;
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.
+ * We could trade memory usage for performance here by iterating
+ * the tree, allocating new refs for each insertion, and then
+ * freeing the entire indirect tree when we're done. In some test
+ * cases, the tree can grow quite large (~200k objects).
*/
- list_for_each_entry_safe(ref, ref_safe, head, list) {
- if (ref->parent) /* already direct */
- continue;
- if (ref->count == 0)
+ while ((rnode = rb_first(&preftrees->indirect.root))) {
+ struct prelim_ref *ref;
+
+ ref = rb_entry(rnode, struct prelim_ref, rbnode);
+ if (WARN(ref->parent,
+ "BUG: direct ref found in indirect tree")) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ rb_erase(&ref->rbnode, &preftrees->indirect.root);
+ preftrees->indirect.count--;
+
+ if (ref->count == 0) {
+ free_pref(ref);
continue;
- if (root_objectid && ref->root_id != root_objectid) {
+ }
+
+ if (sc && sc->root_objectid &&
+ ref->root_id != sc->root_objectid) {
+ free_pref(ref);
ret = BACKREF_FOUND_SHARED;
goto out;
}
- err = __resolve_indirect_ref(fs_info, path, time_seq, ref,
- parents, extent_item_pos,
- total_refs);
+ err = resolve_indirect_ref(fs_info, path, time_seq, ref,
+ parents, extent_item_pos,
+ total_refs);
/*
* we can only tolerate ENOENT,otherwise,we should catch error
* and return directly.
*/
if (err == -ENOENT) {
+ prelim_ref_insert(fs_info, &preftrees->direct, ref,
+ NULL);
continue;
} else if (err) {
+ free_pref(ref);
ret = err;
goto out;
}
@@ -735,68 +680,65 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,
ULIST_ITER_INIT(&uiter);
node = ulist_next(parents, &uiter);
ref->parent = node ? node->val : 0;
- ref->inode_list = node ?
- (struct extent_inode_elem *)(uintptr_t)node->aux : NULL;
+ ref->inode_list = unode_aux_to_inode_list(node);
- /* additional parents require new refs being added here */
+ /* Add a prelim_ref(s) for any other parent(s). */
while ((node = ulist_next(parents, &uiter))) {
+ struct prelim_ref *new_ref;
+
new_ref = kmem_cache_alloc(btrfs_prelim_ref_cache,
GFP_NOFS);
if (!new_ref) {
+ free_pref(ref);
ret = -ENOMEM;
goto out;
}
memcpy(new_ref, ref, sizeof(*ref));
new_ref->parent = node->val;
- new_ref->inode_list = (struct extent_inode_elem *)
- (uintptr_t)node->aux;
- list_add(&new_ref->list, &ref->list);
+ new_ref->inode_list = unode_aux_to_inode_list(node);
+ prelim_ref_insert(fs_info, &preftrees->direct,
+ new_ref, NULL);
}
+
+ /*
+ * Now it's a direct ref, put it in the the direct tree. We must
+ * do this last because the ref could be merged/freed here.
+ */
+ prelim_ref_insert(fs_info, &preftrees->direct, ref, NULL);
+
ulist_reinit(parents);
+ cond_resched();
}
out:
ulist_free(parents);
return ret;
}
-static inline int ref_for_same_block(struct __prelim_ref *ref1,
- struct __prelim_ref *ref2)
-{
- if (ref1->level != ref2->level)
- return 0;
- if (ref1->root_id != ref2->root_id)
- return 0;
- if (ref1->key_for_search.type != ref2->key_for_search.type)
- return 0;
- if (ref1->key_for_search.objectid != ref2->key_for_search.objectid)
- return 0;
- if (ref1->key_for_search.offset != ref2->key_for_search.offset)
- return 0;
- if (ref1->parent != ref2->parent)
- return 0;
-
- return 1;
-}
-
/*
* read tree blocks and add keys where required.
*/
-static int __add_missing_keys(struct btrfs_fs_info *fs_info,
- struct list_head *head)
+static int add_missing_keys(struct btrfs_fs_info *fs_info,
+ struct preftrees *preftrees)
{
- struct __prelim_ref *ref;
+ struct prelim_ref *ref;
struct extent_buffer *eb;
+ struct preftree *tree = &preftrees->indirect_missing_keys;
+ struct rb_node *node;
- list_for_each_entry(ref, head, list) {
- if (ref->parent)
- continue;
- if (ref->key_for_search.type)
- continue;
+ while ((node = rb_first(&tree->root))) {
+ ref = rb_entry(node, struct prelim_ref, rbnode);
+ rb_erase(node, &tree->root);
+
+ BUG_ON(ref->parent); /* should not be a direct ref */
+ BUG_ON(ref->key_for_search.type);
BUG_ON(!ref->wanted_disk_byte);
+
eb = read_tree_block(fs_info, ref->wanted_disk_byte, 0);
if (IS_ERR(eb)) {
+ free_pref(ref);
return PTR_ERR(eb);
} else if (!extent_buffer_uptodate(eb)) {
+ free_pref(ref);
free_extent_buffer(eb);
return -EIO;
}
@@ -807,73 +749,33 @@ static int __add_missing_keys(struct btrfs_fs_info *fs_info,
btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0);
btrfs_tree_read_unlock(eb);
free_extent_buffer(eb);
+ prelim_ref_insert(fs_info, &preftrees->indirect, ref, NULL);
+ cond_resched();
}
return 0;
}
/*
- * merge backrefs and adjust counts accordingly
- *
- * FIXME: For MERGE_IDENTICAL_KEYS, if we add more keys in __add_prelim_ref
- * then we can merge more here. Additionally, we could even add a key
- * range for the blocks we looked into to merge even more (-> replace
- * unresolved refs by those having a parent).
- */
-static void __merge_refs(struct list_head *head, enum merge_mode mode)
-{
- struct __prelim_ref *pos1;
-
- list_for_each_entry(pos1, head, list) {
- struct __prelim_ref *pos2 = pos1, *tmp;
-
- list_for_each_entry_safe_continue(pos2, tmp, head, list) {
- struct __prelim_ref *ref1 = pos1, *ref2 = pos2;
- struct extent_inode_elem *eie;
-
- if (!ref_for_same_block(ref1, ref2))
- continue;
- if (mode == MERGE_IDENTICAL_KEYS) {
- if (!ref1->parent && ref2->parent)
- swap(ref1, ref2);
- } else {
- if (ref1->parent != ref2->parent)
- continue;
- }
-
- eie = ref1->inode_list;
- while (eie && eie->next)
- eie = eie->next;
- if (eie)
- eie->next = ref2->inode_list;
- else
- ref1->inode_list = ref2->inode_list;
- ref1->count += ref2->count;
-
- list_del(&ref2->list);
- kmem_cache_free(btrfs_prelim_ref_cache, ref2);
- cond_resched();
- }
-
- }
-}
-
-/*
* 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 list_head *prefs, u64 *total_refs,
- u64 inum)
+static int add_delayed_refs(const struct btrfs_fs_info *fs_info,
+ struct btrfs_delayed_ref_head *head, u64 seq,
+ struct preftrees *preftrees, u64 *total_refs,
+ 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 op_key = {0};
- int sgn;
+ struct btrfs_key tmp_op_key;
+ struct btrfs_key *op_key = NULL;
+ int count;
int ret = 0;
- if (extent_op && extent_op->update_key)
- btrfs_disk_key_to_cpu(&op_key, &extent_op->key);
+ if (extent_op && extent_op->update_key) {
+ btrfs_disk_key_to_cpu(&tmp_op_key, &extent_op->key);
+ op_key = &tmp_op_key;
+ }
spin_lock(&head->lock);
list_for_each_entry(node, &head->ref_list, list) {
@@ -886,36 +788,40 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq,
WARN_ON(1);
continue;
case BTRFS_ADD_DELAYED_REF:
- sgn = 1;
+ count = node->ref_mod;
break;
case BTRFS_DROP_DELAYED_REF:
- sgn = -1;
+ count = node->ref_mod * -1;
break;
default:
BUG_ON(1);
}
- *total_refs += (node->ref_mod * sgn);
+ *total_refs += count;
switch (node->type) {
case BTRFS_TREE_BLOCK_REF_KEY: {
+ /* NORMAL INDIRECT METADATA backref */
struct btrfs_delayed_tree_ref *ref;
ref = btrfs_delayed_node_to_tree_ref(node);
- ret = __add_prelim_ref(prefs, ref->root, &op_key,
- ref->level + 1, 0, node->bytenr,
- node->ref_mod * sgn, GFP_ATOMIC);
+ ret = add_indirect_ref(fs_info, preftrees, ref->root,
+ &tmp_op_key, ref->level + 1,
+ node->bytenr, count, sc,
+ GFP_ATOMIC);
break;
}
case BTRFS_SHARED_BLOCK_REF_KEY: {
+ /* SHARED DIRECT METADATA backref */
struct btrfs_delayed_tree_ref *ref;
ref = btrfs_delayed_node_to_tree_ref(node);
- ret = __add_prelim_ref(prefs, 0, NULL,
- ref->level + 1, ref->parent,
- node->bytenr,
- node->ref_mod * sgn, GFP_ATOMIC);
+
+ ret = add_direct_ref(fs_info, preftrees, ref->level + 1,
+ ref->parent, node->bytenr, count,
+ sc, GFP_ATOMIC);
break;
}
case BTRFS_EXTENT_DATA_REF_KEY: {
+ /* NORMAL INDIRECT DATA backref */
struct btrfs_delayed_data_ref *ref;
ref = btrfs_delayed_node_to_data_ref(node);
@@ -927,42 +833,53 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq,
* Found a inum that doesn't match our known inum, we
* know it's shared.
*/
- if (inum && ref->objectid != inum) {
+ if (sc && sc->inum && ref->objectid != sc->inum) {
ret = BACKREF_FOUND_SHARED;
- break;
+ goto out;
}
- ret = __add_prelim_ref(prefs, ref->root, &key, 0, 0,
- node->bytenr,
- node->ref_mod * sgn, GFP_ATOMIC);
+ ret = add_indirect_ref(fs_info, preftrees, ref->root,
+ &key, 0, node->bytenr, count, sc,
+ GFP_ATOMIC);
break;
}
case BTRFS_SHARED_DATA_REF_KEY: {
+ /* SHARED DIRECT FULL backref */
struct btrfs_delayed_data_ref *ref;
ref = btrfs_delayed_node_to_data_ref(node);
- ret = __add_prelim_ref(prefs, 0, NULL, 0,
- ref->parent, node->bytenr,
- node->ref_mod * sgn, GFP_ATOMIC);
+
+ ret = add_direct_ref(fs_info, preftrees, 0, ref->parent,
+ node->bytenr, count, sc,
+ GFP_ATOMIC);
break;
}
default:
WARN_ON(1);
}
- if (ret)
+ /*
+ * We must ignore BACKREF_FOUND_SHARED until all delayed
+ * refs have been checked.
+ */
+ if (ret && (ret != BACKREF_FOUND_SHARED))
break;
}
+ if (!ret)
+ ret = extent_is_shared(sc);
+out:
spin_unlock(&head->lock);
return ret;
}
/*
* add all inline backrefs for bytenr to the list
+ *
+ * Returns 0 on success, <0 on error, or BACKREF_FOUND_SHARED.
*/
-static int __add_inline_refs(struct btrfs_path *path, u64 bytenr,
- int *info_level, struct list_head *prefs,
- struct ref_root *ref_tree,
- u64 *total_refs, u64 inum)
+static int add_inline_refs(const struct btrfs_fs_info *fs_info,
+ struct btrfs_path *path, u64 bytenr,
+ int *info_level, struct preftrees *preftrees,
+ u64 *total_refs, struct share_check *sc)
{
int ret = 0;
int slot;
@@ -1012,14 +929,18 @@ static int __add_inline_refs(struct btrfs_path *path, u64 bytenr,
int type;
iref = (struct btrfs_extent_inline_ref *)ptr;
- type = btrfs_extent_inline_ref_type(leaf, iref);
+ type = btrfs_get_extent_inline_ref_type(leaf, iref,
+ BTRFS_REF_TYPE_ANY);
+ if (type == BTRFS_REF_TYPE_INVALID)
+ return -EINVAL;
+
offset = btrfs_extent_inline_ref_offset(leaf, iref);
switch (type) {
case BTRFS_SHARED_BLOCK_REF_KEY:
- ret = __add_prelim_ref(prefs, 0, NULL,
- *info_level + 1, offset,
- bytenr, 1, GFP_NOFS);
+ ret = add_direct_ref(fs_info, preftrees,
+ *info_level + 1, offset,
+ bytenr, 1, NULL, GFP_NOFS);
break;
case BTRFS_SHARED_DATA_REF_KEY: {
struct btrfs_shared_data_ref *sdref;
@@ -1027,21 +948,15 @@ static int __add_inline_refs(struct btrfs_path *path, u64 bytenr,
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, GFP_NOFS);
- if (ref_tree) {
- if (!ret)
- ret = ref_tree_add(ref_tree, 0, 0, 0,
- bytenr, count);
- if (!ret && ref_tree->unique_refs > 1)
- ret = BACKREF_FOUND_SHARED;
- }
+
+ ret = add_direct_ref(fs_info, preftrees, 0, offset,
+ bytenr, count, sc, GFP_NOFS);
break;
}
case BTRFS_TREE_BLOCK_REF_KEY:
- ret = __add_prelim_ref(prefs, offset, NULL,
- *info_level + 1, 0,
- bytenr, 1, GFP_NOFS);
+ ret = add_indirect_ref(fs_info, preftrees, offset,
+ NULL, *info_level + 1,
+ bytenr, 1, NULL, GFP_NOFS);
break;
case BTRFS_EXTENT_DATA_REF_KEY: {
struct btrfs_extent_data_ref *dref;
@@ -1055,23 +970,16 @@ static int __add_inline_refs(struct btrfs_path *path, u64 bytenr,
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = btrfs_extent_data_ref_offset(leaf, dref);
- if (inum && key.objectid != inum) {
+ if (sc && sc->inum && key.objectid != sc->inum) {
ret = BACKREF_FOUND_SHARED;
break;
}
root = btrfs_extent_data_ref_root(leaf, dref);
- ret = __add_prelim_ref(prefs, root, &key, 0, 0,
- bytenr, count, GFP_NOFS);
- if (ref_tree) {
- if (!ret)
- ret = ref_tree_add(ref_tree, root,
- key.objectid,
- key.offset, 0,
- count);
- if (!ret && ref_tree->unique_refs > 1)
- ret = BACKREF_FOUND_SHARED;
- }
+
+ ret = add_indirect_ref(fs_info, preftrees, root,
+ &key, 0, bytenr, count,
+ sc, GFP_NOFS);
break;
}
default:
@@ -1087,11 +995,13 @@ static int __add_inline_refs(struct btrfs_path *path, u64 bytenr,
/*
* add all non-inline backrefs for bytenr to the list
+ *
+ * Returns 0 on success, <0 on error, or BACKREF_FOUND_SHARED.
*/
-static int __add_keyed_refs(struct btrfs_fs_info *fs_info,
- struct btrfs_path *path, u64 bytenr,
- int info_level, struct list_head *prefs,
- struct ref_root *ref_tree, u64 inum)
+static int add_keyed_refs(struct btrfs_fs_info *fs_info,
+ struct btrfs_path *path, u64 bytenr,
+ int info_level, struct preftrees *preftrees,
+ struct share_check *sc)
{
struct btrfs_root *extent_root = fs_info->extent_root;
int ret;
@@ -1121,34 +1031,32 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info,
switch (key.type) {
case BTRFS_SHARED_BLOCK_REF_KEY:
- ret = __add_prelim_ref(prefs, 0, NULL,
- info_level + 1, key.offset,
- bytenr, 1, GFP_NOFS);
+ /* SHARED DIRECT METADATA backref */
+ ret = add_direct_ref(fs_info, preftrees,
+ info_level + 1, key.offset,
+ bytenr, 1, NULL, GFP_NOFS);
break;
case BTRFS_SHARED_DATA_REF_KEY: {
+ /* SHARED DIRECT FULL backref */
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, GFP_NOFS);
- if (ref_tree) {
- if (!ret)
- ret = ref_tree_add(ref_tree, 0, 0, 0,
- bytenr, count);
- if (!ret && ref_tree->unique_refs > 1)
- ret = BACKREF_FOUND_SHARED;
- }
+ ret = add_direct_ref(fs_info, preftrees, 0,
+ key.offset, bytenr, count,
+ sc, GFP_NOFS);
break;
}
case BTRFS_TREE_BLOCK_REF_KEY:
- ret = __add_prelim_ref(prefs, key.offset, NULL,
- info_level + 1, 0,
- bytenr, 1, GFP_NOFS);
+ /* NORMAL INDIRECT METADATA backref */
+ ret = add_indirect_ref(fs_info, preftrees, key.offset,
+ NULL, info_level + 1, bytenr,
+ 1, NULL, GFP_NOFS);
break;
case BTRFS_EXTENT_DATA_REF_KEY: {
+ /* NORMAL INDIRECT DATA backref */
struct btrfs_extent_data_ref *dref;
int count;
u64 root;
@@ -1161,23 +1069,15 @@ 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 (inum && key.objectid != inum) {
+ if (sc && sc->inum && key.objectid != sc->inum) {
ret = BACKREF_FOUND_SHARED;
break;
}
root = btrfs_extent_data_ref_root(leaf, dref);
- ret = __add_prelim_ref(prefs, root, &key, 0, 0,
- bytenr, count, GFP_NOFS);
- if (ref_tree) {
- if (!ret)
- ret = ref_tree_add(ref_tree, root,
- key.objectid,
- key.offset, 0,
- count);
- if (!ret && ref_tree->unique_refs > 1)
- ret = BACKREF_FOUND_SHARED;
- }
+ ret = add_indirect_ref(fs_info, preftrees, root,
+ &key, 0, bytenr, count,
+ sc, GFP_NOFS);
break;
}
default:
@@ -1197,15 +1097,15 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info,
* indirect refs to their parent bytenr.
* When roots are found, they're added to the roots list
*
- * NOTE: This can return values > 0
- *
* If time_seq is set to SEQ_LAST, it will not search delayed_refs, and behave
* much like trans == NULL case, the difference only lies in it will not
* commit root.
* The special case is for qgroup to search roots in commit_transaction().
*
- * If check_shared is set to 1, any extent has more than one ref item, will
- * be returned BACKREF_FOUND_SHARED immediately.
+ * @sc - if !NULL, then immediately return BACKREF_FOUND_SHARED when a
+ * shared extent is detected.
+ *
+ * Otherwise this returns 0 for success and <0 for an error.
*
* FIXME some caching might speed things up
*/
@@ -1213,7 +1113,7 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, u64 bytenr,
u64 time_seq, struct ulist *refs,
struct ulist *roots, const u64 *extent_item_pos,
- u64 root_objectid, u64 inum, int check_shared)
+ struct share_check *sc)
{
struct btrfs_key key;
struct btrfs_path *path;
@@ -1221,15 +1121,16 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans,
struct btrfs_delayed_ref_head *head;
int info_level = 0;
int ret;
- struct list_head prefs_delayed;
- struct list_head prefs;
- struct __prelim_ref *ref;
+ struct prelim_ref *ref;
+ struct rb_node *node;
struct extent_inode_elem *eie = NULL;
- struct ref_root *ref_tree = NULL;
+ /* total of both direct AND indirect refs! */
u64 total_refs = 0;
-
- INIT_LIST_HEAD(&prefs);
- INIT_LIST_HEAD(&prefs_delayed);
+ struct preftrees preftrees = {
+ .direct = PREFTREE_INIT,
+ .indirect = PREFTREE_INIT,
+ .indirect_missing_keys = PREFTREE_INIT
+ };
key.objectid = bytenr;
key.offset = (u64)-1;
@@ -1257,18 +1158,6 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans,
again:
head = NULL;
- if (check_shared) {
- if (!ref_tree) {
- ref_tree = ref_root_alloc();
- if (!ref_tree) {
- ret = -ENOMEM;
- goto out;
- }
- } else {
- ref_root_fini(ref_tree);
- }
- }
-
ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0);
if (ret < 0)
goto out;
@@ -1304,45 +1193,14 @@ again:
goto again;
}
spin_unlock(&delayed_refs->lock);
- ret = __add_delayed_refs(head, time_seq,
- &prefs_delayed, &total_refs,
- inum);
+ ret = add_delayed_refs(fs_info, head, time_seq,
+ &preftrees, &total_refs, sc);
mutex_unlock(&head->mutex);
if (ret)
goto out;
} else {
spin_unlock(&delayed_refs->lock);
}
-
- if (check_shared && !list_empty(&prefs_delayed)) {
- /*
- * Add all delay_ref to the ref_tree and check if there
- * are multiple ref items added.
- */
- list_for_each_entry(ref, &prefs_delayed, list) {
- if (ref->key_for_search.type) {
- ret = ref_tree_add(ref_tree,
- ref->root_id,
- ref->key_for_search.objectid,
- ref->key_for_search.offset,
- 0, ref->count);
- if (ret)
- goto out;
- } else {
- ret = ref_tree_add(ref_tree, 0, 0, 0,
- ref->parent, ref->count);
- if (ret)
- goto out;
- }
-
- }
-
- if (ref_tree->unique_refs > 1) {
- ret = BACKREF_FOUND_SHARED;
- goto out;
- }
-
- }
}
if (path->slots[0]) {
@@ -1356,42 +1214,48 @@ again:
if (key.objectid == bytenr &&
(key.type == BTRFS_EXTENT_ITEM_KEY ||
key.type == BTRFS_METADATA_ITEM_KEY)) {
- ret = __add_inline_refs(path, bytenr,
- &info_level, &prefs,
- ref_tree, &total_refs,
- inum);
+ ret = add_inline_refs(fs_info, path, bytenr,
+ &info_level, &preftrees,
+ &total_refs, sc);
if (ret)
goto out;
- ret = __add_keyed_refs(fs_info, path, bytenr,
- info_level, &prefs,
- ref_tree, inum);
+ ret = add_keyed_refs(fs_info, path, bytenr, info_level,
+ &preftrees, sc);
if (ret)
goto out;
}
}
- btrfs_release_path(path);
- list_splice_init(&prefs_delayed, &prefs);
+ btrfs_release_path(path);
- ret = __add_missing_keys(fs_info, &prefs);
+ ret = add_missing_keys(fs_info, &preftrees);
if (ret)
goto out;
- __merge_refs(&prefs, MERGE_IDENTICAL_KEYS);
+ WARN_ON(!RB_EMPTY_ROOT(&preftrees.indirect_missing_keys.root));
- ret = __resolve_indirect_refs(fs_info, path, time_seq, &prefs,
- extent_item_pos, total_refs,
- root_objectid);
+ ret = resolve_indirect_refs(fs_info, path, time_seq, &preftrees,
+ extent_item_pos, total_refs, sc);
if (ret)
goto out;
- __merge_refs(&prefs, MERGE_IDENTICAL_PARENTS);
+ WARN_ON(!RB_EMPTY_ROOT(&preftrees.indirect.root));
- while (!list_empty(&prefs)) {
- ref = list_first_entry(&prefs, struct __prelim_ref, list);
+ /*
+ * This walks the tree of merged and resolved refs. Tree blocks are
+ * read in as needed. Unique entries are added to the ulist, and
+ * the list of found roots is updated.
+ *
+ * We release the entire tree in one go before returning.
+ */
+ node = rb_first(&preftrees.direct.root);
+ while (node) {
+ ref = rb_entry(node, struct prelim_ref, rbnode);
+ node = rb_next(&ref->rbnode);
WARN_ON(ref->count < 0);
if (roots && ref->count && ref->root_id && ref->parent == 0) {
- if (root_objectid && ref->root_id != root_objectid) {
+ if (sc && sc->root_objectid &&
+ ref->root_id != sc->root_objectid) {
ret = BACKREF_FOUND_SHARED;
goto out;
}
@@ -1442,24 +1306,16 @@ again:
}
eie = NULL;
}
- list_del(&ref->list);
- kmem_cache_free(btrfs_prelim_ref_cache, ref);
+ cond_resched();
}
out:
btrfs_free_path(path);
- ref_root_free(ref_tree);
- while (!list_empty(&prefs)) {
- ref = list_first_entry(&prefs, struct __prelim_ref, list);
- list_del(&ref->list);
- kmem_cache_free(btrfs_prelim_ref_cache, ref);
- }
- while (!list_empty(&prefs_delayed)) {
- ref = list_first_entry(&prefs_delayed, struct __prelim_ref,
- list);
- list_del(&ref->list);
- kmem_cache_free(btrfs_prelim_ref_cache, ref);
- }
+
+ prelim_release(&preftrees.direct);
+ prelim_release(&preftrees.indirect);
+ prelim_release(&preftrees.indirect_missing_keys);
+
if (ret < 0)
free_inode_elem_list(eie);
return ret;
@@ -1475,7 +1331,7 @@ static void free_leaf_list(struct ulist *blocks)
while ((node = ulist_next(blocks, &uiter))) {
if (!node->aux)
continue;
- eie = (struct extent_inode_elem *)(uintptr_t)node->aux;
+ eie = unode_aux_to_inode_list(node);
free_inode_elem_list(eie);
node->aux = 0;
}
@@ -1503,7 +1359,7 @@ static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
return -ENOMEM;
ret = find_parent_nodes(trans, fs_info, bytenr, time_seq,
- *leafs, NULL, extent_item_pos, 0, 0, 0);
+ *leafs, NULL, extent_item_pos, NULL);
if (ret < 0 && ret != -ENOENT) {
free_leaf_list(*leafs);
return ret;
@@ -1525,9 +1381,9 @@ static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
*
* returns 0 on success, < 0 on error.
*/
-static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans,
- struct btrfs_fs_info *fs_info, u64 bytenr,
- u64 time_seq, struct ulist **roots)
+static int btrfs_find_all_roots_safe(struct btrfs_trans_handle *trans,
+ struct btrfs_fs_info *fs_info, u64 bytenr,
+ u64 time_seq, struct ulist **roots)
{
struct ulist *tmp;
struct ulist_node *node = NULL;
@@ -1546,7 +1402,7 @@ static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans,
ULIST_ITER_INIT(&uiter);
while (1) {
ret = find_parent_nodes(trans, fs_info, bytenr, time_seq,
- tmp, *roots, NULL, 0, 0, 0);
+ tmp, *roots, NULL, NULL);
if (ret < 0 && ret != -ENOENT) {
ulist_free(tmp);
ulist_free(*roots);
@@ -1571,7 +1427,8 @@ int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
if (!trans)
down_read(&fs_info->commit_root_sem);
- ret = __btrfs_find_all_roots(trans, fs_info, bytenr, time_seq, roots);
+ ret = btrfs_find_all_roots_safe(trans, fs_info, bytenr,
+ time_seq, roots);
if (!trans)
up_read(&fs_info->commit_root_sem);
return ret;
@@ -1580,26 +1437,32 @@ int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
/**
* btrfs_check_shared - tell us whether an extent is shared
*
- * @trans: optional trans handle
- *
* btrfs_check_shared uses the backref walking code but will short
* circuit as soon as it finds a root or inode that doesn't match the
* one passed in. This provides a significant performance benefit for
* callers (such as fiemap) which want to know whether the extent is
* shared but do not need a ref count.
*
+ * This attempts to allocate a transaction in order to account for
+ * delayed refs, but continues on even when the alloc fails.
+ *
* Return: 0 if extent is not shared, 1 if it is shared, < 0 on error.
*/
-int btrfs_check_shared(struct btrfs_trans_handle *trans,
- struct btrfs_fs_info *fs_info, u64 root_objectid,
- u64 inum, u64 bytenr)
+int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr)
{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_trans_handle *trans;
struct ulist *tmp = NULL;
struct ulist *roots = NULL;
struct ulist_iterator uiter;
struct ulist_node *node;
struct seq_list elem = SEQ_LIST_INIT(elem);
int ret = 0;
+ struct share_check shared = {
+ .root_objectid = root->objectid,
+ .inum = inum,
+ .share_count = 0,
+ };
tmp = ulist_alloc(GFP_NOFS);
roots = ulist_alloc(GFP_NOFS);
@@ -1609,14 +1472,18 @@ int btrfs_check_shared(struct btrfs_trans_handle *trans,
return -ENOMEM;
}
- if (trans)
- btrfs_get_tree_mod_seq(fs_info, &elem);
- else
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans)) {
+ trans = NULL;
down_read(&fs_info->commit_root_sem);
+ } else {
+ btrfs_get_tree_mod_seq(fs_info, &elem);
+ }
+
ULIST_ITER_INIT(&uiter);
while (1) {
ret = find_parent_nodes(trans, fs_info, bytenr, elem.seq, tmp,
- roots, NULL, root_objectid, inum, 1);
+ roots, NULL, &shared);
if (ret == BACKREF_FOUND_SHARED) {
/* this is the only condition under which we return 1 */
ret = 1;
@@ -1631,10 +1498,13 @@ int btrfs_check_shared(struct btrfs_trans_handle *trans,
bytenr = node->val;
cond_resched();
}
- if (trans)
+
+ if (trans) {
btrfs_put_tree_mod_seq(fs_info, &elem);
- else
+ btrfs_end_transaction(trans);
+ } else {
up_read(&fs_info->commit_root_sem);
+ }
ulist_free(tmp);
ulist_free(roots);
return ret;
@@ -1649,7 +1519,7 @@ int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid,
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_inode_extref *extref;
- struct extent_buffer *leaf;
+ const struct extent_buffer *leaf;
unsigned long ptr;
key.objectid = inode_objectid;
@@ -1806,7 +1676,7 @@ int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical,
u64 flags;
u64 size = 0;
u32 item_size;
- struct extent_buffer *eb;
+ const struct extent_buffer *eb;
struct btrfs_extent_item *ei;
struct btrfs_key key;
@@ -1870,15 +1740,17 @@ int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical,
* helper function to iterate extent inline refs. ptr must point to a 0 value
* for the first call and may be modified. it is used to track state.
* if more refs exist, 0 is returned and the next call to
- * __get_extent_inline_ref must pass the modified ptr parameter to get the
+ * get_extent_inline_ref must pass the modified ptr parameter to get the
* next ref. after the last ref was processed, 1 is returned.
* returns <0 on error
*/
-static int __get_extent_inline_ref(unsigned long *ptr, struct extent_buffer *eb,
- struct btrfs_key *key,
- struct btrfs_extent_item *ei, u32 item_size,
- struct btrfs_extent_inline_ref **out_eiref,
- int *out_type)
+static int get_extent_inline_ref(unsigned long *ptr,
+ const struct extent_buffer *eb,
+ const struct btrfs_key *key,
+ const struct btrfs_extent_item *ei,
+ u32 item_size,
+ struct btrfs_extent_inline_ref **out_eiref,
+ int *out_type)
{
unsigned long end;
u64 flags;
@@ -1908,7 +1780,10 @@ static int __get_extent_inline_ref(unsigned long *ptr, struct extent_buffer *eb,
end = (unsigned long)ei + item_size;
*out_eiref = (struct btrfs_extent_inline_ref *)(*ptr);
- *out_type = btrfs_extent_inline_ref_type(eb, *out_eiref);
+ *out_type = btrfs_get_extent_inline_ref_type(eb, *out_eiref,
+ BTRFS_REF_TYPE_ANY);
+ if (*out_type == BTRFS_REF_TYPE_INVALID)
+ return -EINVAL;
*ptr += btrfs_extent_inline_ref_size(*out_type);
WARN_ON(*ptr > end);
@@ -1921,7 +1796,7 @@ static int __get_extent_inline_ref(unsigned long *ptr, struct extent_buffer *eb,
/*
* reads the tree block backref for an extent. tree level and root are returned
* through out_level and out_root. ptr must point to a 0 value for the first
- * call and may be modified (see __get_extent_inline_ref comment).
+ * call and may be modified (see get_extent_inline_ref comment).
* returns 0 if data was provided, 1 if there was no more data to provide or
* <0 on error.
*/
@@ -1937,7 +1812,7 @@ int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb,
return 1;
while (1) {
- ret = __get_extent_inline_ref(ptr, eb, key, ei, item_size,
+ ret = get_extent_inline_ref(ptr, eb, key, ei, item_size,
&eiref, &type);
if (ret < 0)
return ret;
@@ -2034,8 +1909,8 @@ int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
ULIST_ITER_INIT(&ref_uiter);
while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) {
- ret = __btrfs_find_all_roots(trans, fs_info, ref_node->val,
- tree_mod_seq_elem.seq, &roots);
+ ret = btrfs_find_all_roots_safe(trans, fs_info, ref_node->val,
+ tree_mod_seq_elem.seq, &roots);
if (ret)
break;
ULIST_ITER_INIT(&root_uiter);