* [PATCH v2 03/10] Btrfs: mark delayed refs as for cow
2012-01-04 17:35 [PATCH v2 00/10] Btrfs: backref walking rewrite Jan Schmidt
2012-01-04 17:35 ` [PATCH v2 01/10] Btrfs: generic data structure to build unique lists Jan Schmidt
2012-01-04 17:35 ` [PATCH v2 02/10] Btrfs: added helper btrfs_next_item() Jan Schmidt
@ 2012-01-04 17:35 ` Jan Schmidt
2012-01-04 17:35 ` [PATCH v2 04/10] Btrfs: always save ref_root in delayed refs Jan Schmidt
` (7 subsequent siblings)
10 siblings, 0 replies; 13+ messages in thread
From: Jan Schmidt @ 2012-01-04 17:35 UTC (permalink / raw)
To: chris.mason, linux-btrfs
From: Arne Jansen <sensille@gmx.net>
Add a for_cow parameter to add_delayed_*_ref and pass the appropriate value
from every call site. The for_cow parameter will later on be used to
determine if a ref will change anything with respect to qgroups.
Delayed refs coming from relocation are always counted as for_cow, as they
don't change subvol quota.
Also pass in the fs_info for later use.
btrfs_find_all_roots() will use this as an optimization, as changes that are
for_cow will not change anything with respect to which root points to a
certain leaf. Thus, we don't need to add the current sequence number to
those delayed refs.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
---
fs/btrfs/ctree.c | 42 ++++++++++----------
fs/btrfs/ctree.h | 17 ++++----
fs/btrfs/delayed-ref.c | 50 +++++++++++++++---------
fs/btrfs/delayed-ref.h | 15 +++++--
fs/btrfs/disk-io.c | 3 +-
fs/btrfs/extent-tree.c | 101 ++++++++++++++++++++++++++++-------------------
fs/btrfs/file.c | 10 ++--
fs/btrfs/inode.c | 2 +-
fs/btrfs/ioctl.c | 5 +-
fs/btrfs/relocation.c | 18 +++++----
fs/btrfs/transaction.c | 4 +-
fs/btrfs/tree-log.c | 2 +-
12 files changed, 155 insertions(+), 114 deletions(-)
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index dede441..0639a55 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -240,7 +240,7 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans,
cow = btrfs_alloc_free_block(trans, root, buf->len, 0,
new_root_objectid, &disk_key, level,
- buf->start, 0);
+ buf->start, 0, 1);
if (IS_ERR(cow))
return PTR_ERR(cow);
@@ -261,9 +261,9 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans,
WARN_ON(btrfs_header_generation(buf) > trans->transid);
if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID)
- ret = btrfs_inc_ref(trans, root, cow, 1);
+ ret = btrfs_inc_ref(trans, root, cow, 1, 1);
else
- ret = btrfs_inc_ref(trans, root, cow, 0);
+ ret = btrfs_inc_ref(trans, root, cow, 0, 1);
if (ret)
return ret;
@@ -350,14 +350,14 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
if ((owner == root->root_key.objectid ||
root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) &&
!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) {
- ret = btrfs_inc_ref(trans, root, buf, 1);
+ ret = btrfs_inc_ref(trans, root, buf, 1, 1);
BUG_ON(ret);
if (root->root_key.objectid ==
BTRFS_TREE_RELOC_OBJECTID) {
- ret = btrfs_dec_ref(trans, root, buf, 0);
+ ret = btrfs_dec_ref(trans, root, buf, 0, 1);
BUG_ON(ret);
- ret = btrfs_inc_ref(trans, root, cow, 1);
+ ret = btrfs_inc_ref(trans, root, cow, 1, 1);
BUG_ON(ret);
}
new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
@@ -365,9 +365,9 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
if (root->root_key.objectid ==
BTRFS_TREE_RELOC_OBJECTID)
- ret = btrfs_inc_ref(trans, root, cow, 1);
+ ret = btrfs_inc_ref(trans, root, cow, 1, 1);
else
- ret = btrfs_inc_ref(trans, root, cow, 0);
+ ret = btrfs_inc_ref(trans, root, cow, 0, 1);
BUG_ON(ret);
}
if (new_flags != 0) {
@@ -381,11 +381,11 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
if (root->root_key.objectid ==
BTRFS_TREE_RELOC_OBJECTID)
- ret = btrfs_inc_ref(trans, root, cow, 1);
+ ret = btrfs_inc_ref(trans, root, cow, 1, 1);
else
- ret = btrfs_inc_ref(trans, root, cow, 0);
+ ret = btrfs_inc_ref(trans, root, cow, 0, 1);
BUG_ON(ret);
- ret = btrfs_dec_ref(trans, root, buf, 1);
+ ret = btrfs_dec_ref(trans, root, buf, 1, 1);
BUG_ON(ret);
}
clean_tree_block(trans, root, buf);
@@ -446,7 +446,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
cow = btrfs_alloc_free_block(trans, root, buf->len, parent_start,
root->root_key.objectid, &disk_key,
- level, search_start, empty_size);
+ level, search_start, empty_size, 1);
if (IS_ERR(cow))
return PTR_ERR(cow);
@@ -484,7 +484,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
rcu_assign_pointer(root->node, cow);
btrfs_free_tree_block(trans, root, buf, parent_start,
- last_ref);
+ last_ref, 1);
free_extent_buffer(buf);
add_root_to_dirty_list(root);
} else {
@@ -500,7 +500,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
trans->transid);
btrfs_mark_buffer_dirty(parent);
btrfs_free_tree_block(trans, root, buf, parent_start,
- last_ref);
+ last_ref, 1);
}
if (unlock_orig)
btrfs_tree_unlock(buf);
@@ -957,7 +957,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
free_extent_buffer(mid);
root_sub_used(root, mid->len);
- btrfs_free_tree_block(trans, root, mid, 0, 1);
+ btrfs_free_tree_block(trans, root, mid, 0, 1, 0);
/* once for the root ptr */
free_extent_buffer(mid);
return 0;
@@ -1015,7 +1015,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
if (wret)
ret = wret;
root_sub_used(root, right->len);
- btrfs_free_tree_block(trans, root, right, 0, 1);
+ btrfs_free_tree_block(trans, root, right, 0, 1, 0);
free_extent_buffer(right);
right = NULL;
} else {
@@ -1055,7 +1055,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
if (wret)
ret = wret;
root_sub_used(root, mid->len);
- btrfs_free_tree_block(trans, root, mid, 0, 1);
+ btrfs_free_tree_block(trans, root, mid, 0, 1, 0);
free_extent_buffer(mid);
mid = NULL;
} else {
@@ -2089,7 +2089,7 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans,
c = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
root->root_key.objectid, &lower_key,
- level, root->node->start, 0);
+ level, root->node->start, 0, 0);
if (IS_ERR(c))
return PTR_ERR(c);
@@ -2216,7 +2216,7 @@ static noinline int split_node(struct btrfs_trans_handle *trans,
split = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
root->root_key.objectid,
- &disk_key, level, c->start, 0);
+ &disk_key, level, c->start, 0, 0);
if (IS_ERR(split))
return PTR_ERR(split);
@@ -2970,7 +2970,7 @@ again:
right = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
root->root_key.objectid,
- &disk_key, 0, l->start, 0);
+ &disk_key, 0, l->start, 0, 0);
if (IS_ERR(right))
return PTR_ERR(right);
@@ -3781,7 +3781,7 @@ static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
root_sub_used(root, leaf->len);
- btrfs_free_tree_block(trans, root, leaf, 0, 1);
+ btrfs_free_tree_block(trans, root, leaf, 0, 1, 0);
return 0;
}
/*
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3e4a07b..543f60b 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2277,11 +2277,11 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u32 blocksize,
u64 parent, u64 root_objectid,
struct btrfs_disk_key *key, int level,
- u64 hint, u64 empty_size);
+ u64 hint, u64 empty_size, int for_cow);
void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf,
- u64 parent, int last_ref);
+ u64 parent, int last_ref, int for_cow);
struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u32 blocksize,
@@ -2301,17 +2301,17 @@ int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
u64 search_end, struct btrfs_key *ins,
u64 data);
int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
- struct extent_buffer *buf, int full_backref);
+ struct extent_buffer *buf, int full_backref, int for_cow);
int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
- struct extent_buffer *buf, int full_backref);
+ struct extent_buffer *buf, int full_backref, int for_cow);
int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 flags,
int is_data);
int btrfs_free_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
- u64 bytenr, u64 num_bytes, u64 parent,
- u64 root_objectid, u64 owner, u64 offset);
+ u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid,
+ u64 owner, u64 offset, int for_cow);
int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len);
int btrfs_free_and_pin_reserved_extent(struct btrfs_root *root,
@@ -2323,7 +2323,7 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent,
- u64 root_objectid, u64 owner, u64 offset);
+ u64 root_objectid, u64 owner, u64 offset, int for_cow);
int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
@@ -2492,7 +2492,8 @@ static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p)
int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path);
int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf);
void btrfs_drop_snapshot(struct btrfs_root *root,
- struct btrfs_block_rsv *block_rsv, int update_ref);
+ struct btrfs_block_rsv *block_rsv, int update_ref,
+ int for_reloc);
int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *node,
diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index 125cf76..3a0f0ab 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -390,7 +390,8 @@ update_existing_head_ref(struct btrfs_delayed_ref_node *existing,
* this does all the dirty work in terms of maintaining the correct
* overall modification count.
*/
-static noinline int add_delayed_ref_head(struct btrfs_trans_handle *trans,
+static noinline int add_delayed_ref_head(struct btrfs_fs_info *fs_info,
+ struct btrfs_trans_handle *trans,
struct btrfs_delayed_ref_node *ref,
u64 bytenr, u64 num_bytes,
int action, int is_data)
@@ -468,10 +469,12 @@ static noinline int add_delayed_ref_head(struct btrfs_trans_handle *trans,
/*
* helper to insert a delayed tree ref into the rbtree.
*/
-static noinline int add_delayed_tree_ref(struct btrfs_trans_handle *trans,
+static noinline int add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
+ struct btrfs_trans_handle *trans,
struct btrfs_delayed_ref_node *ref,
u64 bytenr, u64 num_bytes, u64 parent,
- u64 ref_root, int level, int action)
+ u64 ref_root, int level, int action,
+ int for_cow)
{
struct btrfs_delayed_ref_node *existing;
struct btrfs_delayed_tree_ref *full_ref;
@@ -522,11 +525,12 @@ static noinline int add_delayed_tree_ref(struct btrfs_trans_handle *trans,
/*
* helper to insert a delayed data ref into the rbtree.
*/
-static noinline int add_delayed_data_ref(struct btrfs_trans_handle *trans,
+static noinline int add_delayed_data_ref(struct btrfs_fs_info *fs_info,
+ struct btrfs_trans_handle *trans,
struct btrfs_delayed_ref_node *ref,
u64 bytenr, u64 num_bytes, u64 parent,
u64 ref_root, u64 owner, u64 offset,
- int action)
+ int action, int for_cow)
{
struct btrfs_delayed_ref_node *existing;
struct btrfs_delayed_data_ref *full_ref;
@@ -554,6 +558,7 @@ static noinline int add_delayed_data_ref(struct btrfs_trans_handle *trans,
full_ref->root = ref_root;
ref->type = BTRFS_EXTENT_DATA_REF_KEY;
}
+
full_ref->objectid = owner;
full_ref->offset = offset;
@@ -580,10 +585,12 @@ static noinline int add_delayed_data_ref(struct btrfs_trans_handle *trans,
* to make sure the delayed ref is eventually processed before this
* transaction commits.
*/
-int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
+int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
+ struct btrfs_trans_handle *trans,
u64 bytenr, u64 num_bytes, u64 parent,
u64 ref_root, int level, int action,
- struct btrfs_delayed_extent_op *extent_op)
+ struct btrfs_delayed_extent_op *extent_op,
+ int for_cow)
{
struct btrfs_delayed_tree_ref *ref;
struct btrfs_delayed_ref_head *head_ref;
@@ -610,12 +617,13 @@ int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
* insert both the head node and the new ref without dropping
* the spin lock
*/
- ret = add_delayed_ref_head(trans, &head_ref->node, bytenr, num_bytes,
- action, 0);
+ ret = add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr,
+ num_bytes, action, 0);
BUG_ON(ret);
- ret = add_delayed_tree_ref(trans, &ref->node, bytenr, num_bytes,
- parent, ref_root, level, action);
+ ret = add_delayed_tree_ref(fs_info, trans, &ref->node, bytenr,
+ num_bytes, parent, ref_root, level, action,
+ for_cow);
BUG_ON(ret);
spin_unlock(&delayed_refs->lock);
return 0;
@@ -624,11 +632,13 @@ int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
/*
* add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref.
*/
-int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
+int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
+ struct btrfs_trans_handle *trans,
u64 bytenr, u64 num_bytes,
u64 parent, u64 ref_root,
u64 owner, u64 offset, int action,
- struct btrfs_delayed_extent_op *extent_op)
+ struct btrfs_delayed_extent_op *extent_op,
+ int for_cow)
{
struct btrfs_delayed_data_ref *ref;
struct btrfs_delayed_ref_head *head_ref;
@@ -655,18 +665,20 @@ int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
* insert both the head node and the new ref without dropping
* the spin lock
*/
- ret = add_delayed_ref_head(trans, &head_ref->node, bytenr, num_bytes,
- action, 1);
+ ret = add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr,
+ num_bytes, action, 1);
BUG_ON(ret);
- ret = add_delayed_data_ref(trans, &ref->node, bytenr, num_bytes,
- parent, ref_root, owner, offset, action);
+ ret = add_delayed_data_ref(fs_info, trans, &ref->node, bytenr,
+ num_bytes, parent, ref_root, owner, offset,
+ action, for_cow);
BUG_ON(ret);
spin_unlock(&delayed_refs->lock);
return 0;
}
-int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
+int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
+ struct btrfs_trans_handle *trans,
u64 bytenr, u64 num_bytes,
struct btrfs_delayed_extent_op *extent_op)
{
@@ -683,7 +695,7 @@ int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
delayed_refs = &trans->transaction->delayed_refs;
spin_lock(&delayed_refs->lock);
- ret = add_delayed_ref_head(trans, &head_ref->node, bytenr,
+ ret = add_delayed_ref_head(fs_info, trans, &head_ref->node, bytenr,
num_bytes, BTRFS_UPDATE_DELAYED_HEAD,
extent_op->is_data);
BUG_ON(ret);
diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h
index e287e3b..8316bff 100644
--- a/fs/btrfs/delayed-ref.h
+++ b/fs/btrfs/delayed-ref.h
@@ -151,16 +151,21 @@ static inline void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref)
}
}
-int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
+int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
+ struct btrfs_trans_handle *trans,
u64 bytenr, u64 num_bytes, u64 parent,
u64 ref_root, int level, int action,
- struct btrfs_delayed_extent_op *extent_op);
-int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_delayed_extent_op *extent_op,
+ int for_cow);
+int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
+ struct btrfs_trans_handle *trans,
u64 bytenr, u64 num_bytes,
u64 parent, u64 ref_root,
u64 owner, u64 offset, int action,
- struct btrfs_delayed_extent_op *extent_op);
-int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
+ struct btrfs_delayed_extent_op *extent_op,
+ int for_cow);
+int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
+ struct btrfs_trans_handle *trans,
u64 bytenr, u64 num_bytes,
struct btrfs_delayed_extent_op *extent_op);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 94abc25..6f8cd17 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1243,7 +1243,8 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
root->ref_cows = 0;
leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
- BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
+ BTRFS_TREE_LOG_OBJECTID, NULL,
+ 0, 0, 0, 0);
if (IS_ERR(leaf)) {
kfree(root);
return ERR_CAST(leaf);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 813c6bb..dc8b9a8 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1872,20 +1872,24 @@ static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent,
- u64 root_objectid, u64 owner, u64 offset)
+ u64 root_objectid, u64 owner, u64 offset, int for_cow)
{
int ret;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+
BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
root_objectid == BTRFS_TREE_LOG_OBJECTID);
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
- ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
+ ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
+ num_bytes,
parent, root_objectid, (int)owner,
- BTRFS_ADD_DELAYED_REF, NULL);
+ BTRFS_ADD_DELAYED_REF, NULL, for_cow);
} else {
- ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
+ ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
+ num_bytes,
parent, root_objectid, owner, offset,
- BTRFS_ADD_DELAYED_REF, NULL);
+ BTRFS_ADD_DELAYED_REF, NULL, for_cow);
}
return ret;
}
@@ -2405,7 +2409,8 @@ int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
extent_op->update_key = 0;
extent_op->is_data = is_data ? 1 : 0;
- ret = btrfs_add_delayed_extent_op(trans, bytenr, num_bytes, extent_op);
+ ret = btrfs_add_delayed_extent_op(root->fs_info, trans, bytenr,
+ num_bytes, extent_op);
if (ret)
kfree(extent_op);
return ret;
@@ -2590,7 +2595,7 @@ out:
static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf,
- int full_backref, int inc)
+ int full_backref, int inc, int for_cow)
{
u64 bytenr;
u64 num_bytes;
@@ -2603,7 +2608,7 @@ static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
int level;
int ret = 0;
int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
- u64, u64, u64, u64, u64, u64);
+ u64, u64, u64, u64, u64, u64, int);
ref_root = btrfs_header_owner(buf);
nritems = btrfs_header_nritems(buf);
@@ -2640,14 +2645,15 @@ static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
key.offset -= btrfs_file_extent_offset(buf, fi);
ret = process_func(trans, root, bytenr, num_bytes,
parent, ref_root, key.objectid,
- key.offset);
+ key.offset, for_cow);
if (ret)
goto fail;
} else {
bytenr = btrfs_node_blockptr(buf, i);
num_bytes = btrfs_level_size(root, level - 1);
ret = process_func(trans, root, bytenr, num_bytes,
- parent, ref_root, level - 1, 0);
+ parent, ref_root, level - 1, 0,
+ for_cow);
if (ret)
goto fail;
}
@@ -2659,15 +2665,15 @@ fail:
}
int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
- struct extent_buffer *buf, int full_backref)
+ struct extent_buffer *buf, int full_backref, int for_cow)
{
- return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
+ return __btrfs_mod_ref(trans, root, buf, full_backref, 1, for_cow);
}
int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
- struct extent_buffer *buf, int full_backref)
+ struct extent_buffer *buf, int full_backref, int for_cow)
{
- return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
+ return __btrfs_mod_ref(trans, root, buf, full_backref, 0, for_cow);
}
static int write_one_cache_group(struct btrfs_trans_handle *trans,
@@ -4937,16 +4943,17 @@ out:
void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf,
- u64 parent, int last_ref)
+ u64 parent, int last_ref, int for_cow)
{
struct btrfs_block_group_cache *cache = NULL;
int ret;
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
- ret = btrfs_add_delayed_tree_ref(trans, buf->start, buf->len,
- parent, root->root_key.objectid,
- btrfs_header_level(buf),
- BTRFS_DROP_DELAYED_REF, NULL);
+ ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
+ buf->start, buf->len,
+ parent, root->root_key.objectid,
+ btrfs_header_level(buf),
+ BTRFS_DROP_DELAYED_REF, NULL, for_cow);
BUG_ON(ret);
}
@@ -4981,12 +4988,12 @@ out:
btrfs_put_block_group(cache);
}
-int btrfs_free_extent(struct btrfs_trans_handle *trans,
- struct btrfs_root *root,
- u64 bytenr, u64 num_bytes, u64 parent,
- u64 root_objectid, u64 owner, u64 offset)
+int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+ u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid,
+ u64 owner, u64 offset, int for_cow)
{
int ret;
+ struct btrfs_fs_info *fs_info = root->fs_info;
/*
* tree log blocks never actually go into the extent allocation
@@ -4998,14 +5005,17 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans,
btrfs_pin_extent(root, bytenr, num_bytes, 1);
ret = 0;
} else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
- ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes,
+ ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
+ num_bytes,
parent, root_objectid, (int)owner,
- BTRFS_DROP_DELAYED_REF, NULL);
+ BTRFS_DROP_DELAYED_REF, NULL, for_cow);
BUG_ON(ret);
} else {
- ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes,
- parent, root_objectid, owner,
- offset, BTRFS_DROP_DELAYED_REF, NULL);
+ ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
+ num_bytes,
+ parent, root_objectid, owner,
+ offset, BTRFS_DROP_DELAYED_REF,
+ NULL, for_cow);
BUG_ON(ret);
}
return ret;
@@ -5826,9 +5836,10 @@ int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
- ret = btrfs_add_delayed_data_ref(trans, ins->objectid, ins->offset,
- 0, root_objectid, owner, offset,
- BTRFS_ADD_DELAYED_EXTENT, NULL);
+ ret = btrfs_add_delayed_data_ref(root->fs_info, trans, ins->objectid,
+ ins->offset, 0,
+ root_objectid, owner, offset,
+ BTRFS_ADD_DELAYED_EXTENT, NULL, 0);
return ret;
}
@@ -5998,7 +6009,7 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u32 blocksize,
u64 parent, u64 root_objectid,
struct btrfs_disk_key *key, int level,
- u64 hint, u64 empty_size)
+ u64 hint, u64 empty_size, int for_cow)
{
struct btrfs_key ins;
struct btrfs_block_rsv *block_rsv;
@@ -6042,10 +6053,11 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
extent_op->update_flags = 1;
extent_op->is_data = 0;
- ret = btrfs_add_delayed_tree_ref(trans, ins.objectid,
+ ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
+ ins.objectid,
ins.offset, parent, root_objectid,
level, BTRFS_ADD_DELAYED_EXTENT,
- extent_op);
+ extent_op, for_cow);
BUG_ON(ret);
}
return buf;
@@ -6062,6 +6074,7 @@ struct walk_control {
int keep_locks;
int reada_slot;
int reada_count;
+ int for_reloc;
};
#define DROP_REFERENCE 1
@@ -6200,9 +6213,9 @@ static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
/* wc->stage == UPDATE_BACKREF */
if (!(wc->flags[level] & flag)) {
BUG_ON(!path->locks[level]);
- ret = btrfs_inc_ref(trans, root, eb, 1);
+ ret = btrfs_inc_ref(trans, root, eb, 1, wc->for_reloc);
BUG_ON(ret);
- ret = btrfs_dec_ref(trans, root, eb, 0);
+ ret = btrfs_dec_ref(trans, root, eb, 0, wc->for_reloc);
BUG_ON(ret);
ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
eb->len, flag, 0);
@@ -6346,7 +6359,7 @@ skip:
}
ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
- root->root_key.objectid, level - 1, 0);
+ root->root_key.objectid, level - 1, 0, 0);
BUG_ON(ret);
}
btrfs_tree_unlock(next);
@@ -6420,9 +6433,11 @@ static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
if (wc->refs[level] == 1) {
if (level == 0) {
if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
- ret = btrfs_dec_ref(trans, root, eb, 1);
+ ret = btrfs_dec_ref(trans, root, eb, 1,
+ wc->for_reloc);
else
- ret = btrfs_dec_ref(trans, root, eb, 0);
+ ret = btrfs_dec_ref(trans, root, eb, 0,
+ wc->for_reloc);
BUG_ON(ret);
}
/* make block locked assertion in clean_tree_block happy */
@@ -6449,7 +6464,7 @@ static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
btrfs_header_owner(path->nodes[level + 1]));
}
- btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1);
+ btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1, 0);
out:
wc->refs[level] = 0;
wc->flags[level] = 0;
@@ -6533,7 +6548,8 @@ static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
* blocks are properly updated.
*/
void btrfs_drop_snapshot(struct btrfs_root *root,
- struct btrfs_block_rsv *block_rsv, int update_ref)
+ struct btrfs_block_rsv *block_rsv, int update_ref,
+ int for_reloc)
{
struct btrfs_path *path;
struct btrfs_trans_handle *trans;
@@ -6621,6 +6637,7 @@ void btrfs_drop_snapshot(struct btrfs_root *root,
wc->stage = DROP_REFERENCE;
wc->update_ref = update_ref;
wc->keep_locks = 0;
+ wc->for_reloc = for_reloc;
wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
while (1) {
@@ -6705,6 +6722,7 @@ out:
* drop subtree rooted at tree block 'node'.
*
* NOTE: this function will unlock and release tree block 'node'
+ * only used by relocation code
*/
int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
@@ -6749,6 +6767,7 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
wc->stage = DROP_REFERENCE;
wc->update_ref = 0;
wc->keep_locks = 1;
+ wc->for_reloc = 1;
wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
while (1) {
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index f2e9282..d2b60ed 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -678,7 +678,7 @@ next_slot:
disk_bytenr, num_bytes, 0,
root->root_key.objectid,
new_key.objectid,
- start - extent_offset);
+ start - extent_offset, 0);
BUG_ON(ret);
*hint_byte = disk_bytenr;
}
@@ -753,7 +753,7 @@ next_slot:
disk_bytenr, num_bytes, 0,
root->root_key.objectid,
key.objectid, key.offset -
- extent_offset);
+ extent_offset, 0);
BUG_ON(ret);
inode_sub_bytes(inode,
extent_end - key.offset);
@@ -962,7 +962,7 @@ again:
ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0,
root->root_key.objectid,
- ino, orig_offset);
+ ino, orig_offset, 0);
BUG_ON(ret);
if (split == start) {
@@ -989,7 +989,7 @@ again:
del_nr++;
ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
0, root->root_key.objectid,
- ino, orig_offset);
+ ino, orig_offset, 0);
BUG_ON(ret);
}
other_start = 0;
@@ -1006,7 +1006,7 @@ again:
del_nr++;
ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
0, root->root_key.objectid,
- ino, orig_offset);
+ ino, orig_offset, 0);
BUG_ON(ret);
}
if (del_nr == 0) {
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index c5ccec2..ea81938 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3139,7 +3139,7 @@ delete:
ret = btrfs_free_extent(trans, root, extent_start,
extent_num_bytes, 0,
btrfs_header_owner(leaf),
- ino, extent_offset);
+ ino, extent_offset, 0);
BUG_ON(ret);
}
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 72d4616..c48f2e9 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -358,7 +358,7 @@ static noinline int create_subvol(struct btrfs_root *root,
return PTR_ERR(trans);
leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
- 0, objectid, NULL, 0, 0, 0);
+ 0, objectid, NULL, 0, 0, 0, 0);
if (IS_ERR(leaf)) {
ret = PTR_ERR(leaf);
goto fail;
@@ -2425,7 +2425,8 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
disko, diskl, 0,
root->root_key.objectid,
btrfs_ino(inode),
- new_key.offset - datao);
+ new_key.offset - datao,
+ 0);
BUG_ON(ret);
}
} else if (type == BTRFS_FILE_EXTENT_INLINE) {
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index dff29d5..8c1aae2 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -1604,12 +1604,12 @@ int replace_file_extents(struct btrfs_trans_handle *trans,
ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
num_bytes, parent,
btrfs_header_owner(leaf),
- key.objectid, key.offset);
+ key.objectid, key.offset, 1);
BUG_ON(ret);
ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
parent, btrfs_header_owner(leaf),
- key.objectid, key.offset);
+ key.objectid, key.offset, 1);
BUG_ON(ret);
}
if (dirty)
@@ -1778,21 +1778,23 @@ again:
ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
path->nodes[level]->start,
- src->root_key.objectid, level - 1, 0);
+ src->root_key.objectid, level - 1, 0,
+ 1);
BUG_ON(ret);
ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
0, dest->root_key.objectid, level - 1,
- 0);
+ 0, 1);
BUG_ON(ret);
ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
path->nodes[level]->start,
- src->root_key.objectid, level - 1, 0);
+ src->root_key.objectid, level - 1, 0,
+ 1);
BUG_ON(ret);
ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
0, dest->root_key.objectid, level - 1,
- 0);
+ 0, 1);
BUG_ON(ret);
btrfs_unlock_up_safe(path, 0);
@@ -2244,7 +2246,7 @@ again:
} else {
list_del_init(&reloc_root->root_list);
}
- btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0);
+ btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1);
}
if (found) {
@@ -2558,7 +2560,7 @@ static int do_relocation(struct btrfs_trans_handle *trans,
node->eb->start, blocksize,
upper->eb->start,
btrfs_header_owner(upper->eb),
- node->level, 0);
+ node->level, 0, 1);
BUG_ON(ret);
ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 81376d9..a2bfedc 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1393,9 +1393,9 @@ int btrfs_clean_old_snapshots(struct btrfs_root *root)
if (btrfs_header_backref_rev(root->node) <
BTRFS_MIXED_BACKREF_REV)
- btrfs_drop_snapshot(root, NULL, 0);
+ btrfs_drop_snapshot(root, NULL, 0, 0);
else
- btrfs_drop_snapshot(root, NULL, 1);
+ btrfs_drop_snapshot(root, NULL, 1, 0);
}
return 0;
}
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index f4d81c0..fce7b9e 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -589,7 +589,7 @@ static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
ret = btrfs_inc_extent_ref(trans, root,
ins.objectid, ins.offset,
0, root->root_key.objectid,
- key->objectid, offset);
+ key->objectid, offset, 0);
BUG_ON(ret);
} else {
/*
--
1.7.3.4
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v2 09/10] Btrfs: added btrfs_find_all_roots()
2012-01-04 17:35 [PATCH v2 00/10] Btrfs: backref walking rewrite Jan Schmidt
` (7 preceding siblings ...)
2012-01-04 17:35 ` [PATCH v2 08/10] Btrfs: add waitqueue instead of doing busy waiting for more delayed refs Jan Schmidt
@ 2012-01-04 17:35 ` Jan Schmidt
2012-01-04 17:35 ` [PATCH v2 10/10] Btrfs: new backref walking code Jan Schmidt
2012-01-05 5:38 ` [PATCH v2 00/10] Btrfs: backref walking rewrite Li Zefan
10 siblings, 0 replies; 13+ messages in thread
From: Jan Schmidt @ 2012-01-04 17:35 UTC (permalink / raw)
To: chris.mason, linux-btrfs
This function gets a byte number (a data extent), collects all the leafs
pointing to it and walks up the trees to find all fs roots pointing to those
leafs. It also returns the list of all leafs pointing to that extent.
It does proper locking for the involved trees, can be used on busy file
systems and honors delayed refs.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
---
fs/btrfs/backref.c | 783 ++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/btrfs/backref.h | 5 +
2 files changed, 788 insertions(+), 0 deletions(-)
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 22c64ff..03c30a1 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -19,6 +19,9 @@
#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;
@@ -32,6 +35,786 @@ struct __shared_ref {
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)
diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h
index 9261883..d00dfa9 100644
--- a/fs/btrfs/backref.h
+++ b/fs/btrfs/backref.h
@@ -20,6 +20,7 @@
#define __BTRFS_BACKREF__
#include "ioctl.h"
+#include "ulist.h"
struct inode_fs_paths {
struct btrfs_path *btrfs_path;
@@ -54,6 +55,10 @@ int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info,
int paths_from_inode(u64 inum, struct inode_fs_paths *ipath);
+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 btrfs_data_container *init_data_container(u32 total_bytes);
struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root,
struct btrfs_path *path);
--
1.7.3.4
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v2 10/10] Btrfs: new backref walking code
2012-01-04 17:35 [PATCH v2 00/10] Btrfs: backref walking rewrite Jan Schmidt
` (8 preceding siblings ...)
2012-01-04 17:35 ` [PATCH v2 09/10] Btrfs: added btrfs_find_all_roots() Jan Schmidt
@ 2012-01-04 17:35 ` Jan Schmidt
2012-01-05 5:38 ` [PATCH v2 00/10] Btrfs: backref walking rewrite Li Zefan
10 siblings, 0 replies; 13+ messages in thread
From: Jan Schmidt @ 2012-01-04 17:35 UTC (permalink / raw)
To: chris.mason, linux-btrfs
The old backref iteration code could only safely be used on commit roots.
Besides this limitation, it had bugs in finding the roots for these
references. This commit replaces large parts of it by btrfs_find_all_roots()
which a) really finds all roots and the correct roots, b) works correctly
under heavy file system load, c) considers delayed refs.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
---
fs/btrfs/backref.c | 354 +++++++++++++++-------------------------------------
fs/btrfs/ioctl.c | 8 +-
fs/btrfs/scrub.c | 7 +-
3 files changed, 107 insertions(+), 262 deletions(-)
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 03c30a1..c4c3d5d 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -23,18 +23,6 @@
#include "transaction.h"
#include "delayed-ref.h"
-struct __data_ref {
- struct list_head list;
- u64 inum;
- u64 root;
- u64 extent_data_item_offset;
-};
-
-struct __shared_ref {
- struct list_head list;
- u64 disk_byte;
-};
-
/*
* this structure records all encountered refs on the way up to the root
*/
@@ -964,8 +952,11 @@ int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical,
btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]);
if (found_key->type != BTRFS_EXTENT_ITEM_KEY ||
found_key->objectid > logical ||
- found_key->objectid + found_key->offset <= logical)
+ found_key->objectid + found_key->offset <= logical) {
+ pr_debug("logical %llu is not within any extent\n",
+ (unsigned long long)logical);
return -ENOENT;
+ }
eb = path->nodes[0];
item_size = btrfs_item_size_nr(eb, path->slots[0]);
@@ -974,6 +965,13 @@ int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical,
ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
flags = btrfs_extent_flags(eb, ei);
+ pr_debug("logical %llu is at position %llu within the extent (%llu "
+ "EXTENT_ITEM %llu) flags %#llx size %u\n",
+ (unsigned long long)logical,
+ (unsigned long long)(logical - found_key->objectid),
+ (unsigned long long)found_key->objectid,
+ (unsigned long long)found_key->offset,
+ (unsigned long long)flags, item_size);
if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
return BTRFS_EXTENT_FLAG_TREE_BLOCK;
if (flags & BTRFS_EXTENT_FLAG_DATA)
@@ -1070,128 +1068,11 @@ int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb,
return 0;
}
-static int __data_list_add(struct list_head *head, u64 inum,
- u64 extent_data_item_offset, u64 root)
-{
- struct __data_ref *ref;
-
- ref = kmalloc(sizeof(*ref), GFP_NOFS);
- if (!ref)
- return -ENOMEM;
-
- ref->inum = inum;
- ref->extent_data_item_offset = extent_data_item_offset;
- ref->root = root;
- list_add_tail(&ref->list, head);
-
- return 0;
-}
-
-static int __data_list_add_eb(struct list_head *head, struct extent_buffer *eb,
- struct btrfs_extent_data_ref *dref)
-{
- return __data_list_add(head, btrfs_extent_data_ref_objectid(eb, dref),
- btrfs_extent_data_ref_offset(eb, dref),
- btrfs_extent_data_ref_root(eb, dref));
-}
-
-static int __shared_list_add(struct list_head *head, u64 disk_byte)
-{
- struct __shared_ref *ref;
-
- ref = kmalloc(sizeof(*ref), GFP_NOFS);
- if (!ref)
- return -ENOMEM;
-
- ref->disk_byte = disk_byte;
- list_add_tail(&ref->list, head);
-
- return 0;
-}
-
-static int __iter_shared_inline_ref_inodes(struct btrfs_fs_info *fs_info,
- u64 logical, u64 inum,
- u64 extent_data_item_offset,
- u64 extent_offset,
- struct btrfs_path *path,
- struct list_head *data_refs,
- iterate_extent_inodes_t *iterate,
- void *ctx)
-{
- u64 ref_root;
- u32 item_size;
- struct btrfs_key key;
- struct extent_buffer *eb;
- struct btrfs_extent_item *ei;
- struct btrfs_extent_inline_ref *eiref;
- struct __data_ref *ref;
- int ret;
- int type;
- int last;
- unsigned long ptr = 0;
-
- WARN_ON(!list_empty(data_refs));
- ret = extent_from_logical(fs_info, logical, path, &key);
- if (ret & BTRFS_EXTENT_FLAG_DATA)
- ret = -EIO;
- if (ret < 0)
- goto out;
-
- eb = path->nodes[0];
- ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
- item_size = btrfs_item_size_nr(eb, path->slots[0]);
-
- ret = 0;
- ref_root = 0;
- /*
- * as done in iterate_extent_inodes, we first build a list of refs to
- * iterate, then free the path and then iterate them to avoid deadlocks.
- */
- do {
- last = __get_extent_inline_ref(&ptr, eb, ei, item_size,
- &eiref, &type);
- if (last < 0) {
- ret = last;
- goto out;
- }
- if (type == BTRFS_TREE_BLOCK_REF_KEY ||
- type == BTRFS_SHARED_BLOCK_REF_KEY) {
- ref_root = btrfs_extent_inline_ref_offset(eb, eiref);
- ret = __data_list_add(data_refs, inum,
- extent_data_item_offset,
- ref_root);
- }
- } while (!ret && !last);
-
- btrfs_release_path(path);
-
- if (ref_root == 0) {
- printk(KERN_ERR "btrfs: failed to find tree block ref "
- "for shared data backref %llu\n", logical);
- WARN_ON(1);
- ret = -EIO;
- }
-
-out:
- while (!list_empty(data_refs)) {
- ref = list_first_entry(data_refs, struct __data_ref, list);
- list_del(&ref->list);
- if (!ret)
- ret = iterate(ref->inum, extent_offset +
- ref->extent_data_item_offset,
- ref->root, ctx);
- kfree(ref);
- }
-
- return ret;
-}
-
-static int __iter_shared_inline_ref(struct btrfs_fs_info *fs_info,
- u64 logical, u64 orig_extent_item_objectid,
- u64 extent_offset, struct btrfs_path *path,
- struct list_head *data_refs,
- iterate_extent_inodes_t *iterate,
- void *ctx)
+static int iterate_leaf_refs(struct btrfs_fs_info *fs_info,
+ struct btrfs_path *path, u64 logical,
+ u64 orig_extent_item_objectid,
+ u64 extent_item_pos, u64 root,
+ iterate_extent_inodes_t *iterate, void *ctx)
{
u64 disk_byte;
struct btrfs_key key;
@@ -1199,8 +1080,10 @@ static int __iter_shared_inline_ref(struct btrfs_fs_info *fs_info,
struct extent_buffer *eb;
int slot;
int nritems;
- int ret;
- int found = 0;
+ int ret = 0;
+ int extent_type;
+ u64 data_offset;
+ u64 data_len;
eb = read_tree_block(fs_info->tree_root, logical,
fs_info->tree_root->leafsize, 0);
@@ -1218,149 +1101,99 @@ static int __iter_shared_inline_ref(struct btrfs_fs_info *fs_info,
if (key.type != BTRFS_EXTENT_DATA_KEY)
continue;
fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
- if (!fi) {
- free_extent_buffer(eb);
- return -EIO;
- }
+ extent_type = btrfs_file_extent_type(eb, fi);
+ if (extent_type == BTRFS_FILE_EXTENT_INLINE)
+ continue;
+ /* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */
disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
- if (disk_byte != orig_extent_item_objectid) {
- if (found)
- break;
- else
- continue;
- }
- ++found;
- ret = __iter_shared_inline_ref_inodes(fs_info, logical,
- key.objectid,
- key.offset,
- extent_offset, path,
- data_refs,
- iterate, ctx);
- if (ret)
- break;
- }
+ if (disk_byte != orig_extent_item_objectid)
+ continue;
- if (!found) {
- printk(KERN_ERR "btrfs: failed to follow shared data backref "
- "to parent %llu\n", logical);
- WARN_ON(1);
- ret = -EIO;
+ data_offset = btrfs_file_extent_offset(eb, fi);
+ data_len = btrfs_file_extent_num_bytes(eb, fi);
+
+ if (extent_item_pos < data_offset ||
+ extent_item_pos >= data_offset + data_len)
+ continue;
+
+ pr_debug("ref for %llu resolved, key (%llu EXTEND_DATA %llu), "
+ "root %llu\n", orig_extent_item_objectid,
+ key.objectid, key.offset, root);
+ ret = iterate(key.objectid,
+ key.offset + (extent_item_pos - data_offset),
+ root, ctx);
+ if (ret) {
+ pr_debug("stopping iteration because ret=%d\n", ret);
+ break;
+ }
}
free_extent_buffer(eb);
+
return ret;
}
/*
* calls iterate() for every inode that references the extent identified by
- * the given parameters. will use the path given as a parameter and return it
- * released.
+ * the given parameters.
* when the iterator function returns a non-zero value, iteration stops.
+ * path is guaranteed to be in released state when iterate() is called.
*/
int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
struct btrfs_path *path,
- u64 extent_item_objectid,
- u64 extent_offset,
+ u64 extent_item_objectid, u64 extent_item_pos,
iterate_extent_inodes_t *iterate, void *ctx)
{
- unsigned long ptr = 0;
- int last;
int ret;
- int type;
- u64 logical;
- u32 item_size;
- struct btrfs_extent_inline_ref *eiref;
- struct btrfs_extent_data_ref *dref;
- struct extent_buffer *eb;
- struct btrfs_extent_item *ei;
- struct btrfs_key key;
struct list_head data_refs = LIST_HEAD_INIT(data_refs);
struct list_head shared_refs = LIST_HEAD_INIT(shared_refs);
- struct __data_ref *ref_d;
- struct __shared_ref *ref_s;
+ struct btrfs_trans_handle *trans;
+ struct ulist *refs;
+ struct ulist *roots;
+ struct ulist_node *ref_node = NULL;
+ struct ulist_node *root_node = NULL;
+ struct seq_list seq_elem;
+ struct btrfs_delayed_ref_root *delayed_refs;
- eb = path->nodes[0];
- ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
- item_size = btrfs_item_size_nr(eb, path->slots[0]);
-
- /* first we iterate the inline refs, ... */
- do {
- last = __get_extent_inline_ref(&ptr, eb, ei, item_size,
- &eiref, &type);
- if (last == -ENOENT) {
- ret = 0;
- break;
- }
- if (last < 0) {
- ret = last;
- break;
- }
+ trans = btrfs_join_transaction(fs_info->extent_root);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
- if (type == BTRFS_EXTENT_DATA_REF_KEY) {
- dref = (struct btrfs_extent_data_ref *)(&eiref->offset);
- ret = __data_list_add_eb(&data_refs, eb, dref);
- } else if (type == BTRFS_SHARED_DATA_REF_KEY) {
- logical = btrfs_extent_inline_ref_offset(eb, eiref);
- ret = __shared_list_add(&shared_refs, logical);
- }
- } while (!ret && !last);
+ pr_debug("resolving all inodes for extent %llu\n",
+ extent_item_objectid);
- /* ... then we proceed to in-tree references and ... */
- while (!ret) {
- ++path->slots[0];
- if (path->slots[0] > btrfs_header_nritems(eb)) {
- ret = btrfs_next_leaf(fs_info->extent_root, path);
- if (ret) {
- if (ret == 1)
- ret = 0; /* we're done */
- break;
- }
- eb = path->nodes[0];
- }
- btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
- if (key.objectid != extent_item_objectid)
- break;
- if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
- dref = btrfs_item_ptr(eb, path->slots[0],
- struct btrfs_extent_data_ref);
- ret = __data_list_add_eb(&data_refs, eb, dref);
- } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
- ret = __shared_list_add(&shared_refs, key.offset);
- }
- }
+ delayed_refs = &trans->transaction->delayed_refs;
+ spin_lock(&delayed_refs->lock);
+ btrfs_get_delayed_seq(delayed_refs, &seq_elem);
+ spin_unlock(&delayed_refs->lock);
- btrfs_release_path(path);
+ ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid,
+ extent_item_pos, seq_elem.seq,
+ &refs);
- /*
- * ... only at the very end we can process the refs we found. this is
- * because the iterator function we call is allowed to make tree lookups
- * and we have to avoid deadlocks. additionally, we need more tree
- * lookups ourselves for shared data refs.
- */
- while (!list_empty(&data_refs)) {
- ref_d = list_first_entry(&data_refs, struct __data_ref, list);
- list_del(&ref_d->list);
- if (!ret)
- ret = iterate(ref_d->inum, extent_offset +
- ref_d->extent_data_item_offset,
- ref_d->root, ctx);
- kfree(ref_d);
- }
+ if (ret)
+ goto out;
- while (!list_empty(&shared_refs)) {
- ref_s = list_first_entry(&shared_refs, struct __shared_ref,
- list);
- list_del(&ref_s->list);
- if (!ret)
- ret = __iter_shared_inline_ref(fs_info,
- ref_s->disk_byte,
- extent_item_objectid,
- extent_offset, path,
- &data_refs,
- iterate, ctx);
- kfree(ref_s);
+ while (!ret && (ref_node = ulist_next(refs, ref_node))) {
+ ret = btrfs_find_all_roots(trans, fs_info, ref_node->val, -1,
+ seq_elem.seq, &roots);
+ if (ret)
+ break;
+ while (!ret && (root_node = ulist_next(roots, root_node))) {
+ pr_debug("root %llu references leaf %llu\n",
+ root_node->val, ref_node->val);
+ ret = iterate_leaf_refs(fs_info, path, ref_node->val,
+ extent_item_objectid,
+ extent_item_pos, root_node->val,
+ iterate, ctx);
+ }
}
+ ulist_free(refs);
+ ulist_free(roots);
+out:
+ btrfs_put_delayed_seq(delayed_refs, &seq_elem);
+ btrfs_end_transaction(trans, fs_info->extent_root);
return ret;
}
@@ -1369,19 +1202,20 @@ int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info,
iterate_extent_inodes_t *iterate, void *ctx)
{
int ret;
- u64 offset;
+ u64 extent_item_pos;
struct btrfs_key found_key;
ret = extent_from_logical(fs_info, logical, path,
&found_key);
+ btrfs_release_path(path);
if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK)
ret = -EINVAL;
if (ret < 0)
return ret;
- offset = logical - found_key.objectid;
+ extent_item_pos = logical - found_key.objectid;
ret = iterate_extent_inodes(fs_info, path, found_key.objectid,
- offset, iterate, ctx);
+ extent_item_pos, iterate, ctx);
return ret;
}
@@ -1426,6 +1260,10 @@ static int iterate_irefs(u64 inum, struct btrfs_root *fs_root,
for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) {
name_len = btrfs_inode_ref_name_len(eb, iref);
/* path must be released before calling iterate()! */
+ pr_debug("following ref at offset %u for inode %llu in "
+ "tree %llu\n", cur,
+ (unsigned long long)found_key.objectid,
+ (unsigned long long)fs_root->objectid);
ret = iterate(parent, iref, eb, ctx);
if (ret) {
free_extent_buffer(eb);
@@ -1466,10 +1304,14 @@ static int inode_to_path(u64 inum, struct btrfs_inode_ref *iref,
return PTR_ERR(fspath);
if (fspath > fspath_min) {
+ pr_debug("path resolved: %s\n", fspath);
ipath->fspath->val[i] = (u64)(unsigned long)fspath;
++ipath->fspath->elem_cnt;
ipath->fspath->bytes_left = fspath - fspath_min;
} else {
+ pr_debug("missed path, not enough space. missing bytes: %ld, "
+ "constructed so far: %s\n", fspath_min - fspath,
+ fspath_min);
++ipath->fspath->elem_missed;
ipath->fspath->bytes_missing += fspath_min - fspath;
ipath->fspath->bytes_left = 0;
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index c48f2e9..9b05268 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2976,7 +2976,7 @@ static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
{
int ret = 0;
int size;
- u64 extent_offset;
+ u64 extent_item_pos;
struct btrfs_ioctl_logical_ino_args *loi;
struct btrfs_data_container *inodes = NULL;
struct btrfs_path *path = NULL;
@@ -3007,15 +3007,17 @@ static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
}
ret = extent_from_logical(root->fs_info, loi->logical, path, &key);
+ btrfs_release_path(path);
if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK)
ret = -ENOENT;
if (ret < 0)
goto out;
- extent_offset = loi->logical - key.objectid;
+ extent_item_pos = loi->logical - key.objectid;
ret = iterate_extent_inodes(root->fs_info, path, key.objectid,
- extent_offset, build_ino_list, inodes);
+ extent_item_pos, build_ino_list,
+ inodes);
if (ret < 0)
goto out;
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index c27bcb6..b5edff2 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -309,7 +309,7 @@ static void scrub_print_warning(const char *errstr, struct scrub_bio *sbio,
u8 ref_level;
unsigned long ptr = 0;
const int bufsize = 4096;
- u64 extent_offset;
+ u64 extent_item_pos;
path = btrfs_alloc_path();
@@ -329,12 +329,13 @@ static void scrub_print_warning(const char *errstr, struct scrub_bio *sbio,
if (ret < 0)
goto out;
- extent_offset = swarn.logical - found_key.objectid;
+ extent_item_pos = swarn.logical - found_key.objectid;
swarn.extent_item_size = found_key.offset;
eb = path->nodes[0];
ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
item_size = btrfs_item_size_nr(eb, path->slots[0]);
+ btrfs_release_path(path);
if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
do {
@@ -351,7 +352,7 @@ static void scrub_print_warning(const char *errstr, struct scrub_bio *sbio,
} else {
swarn.path = path;
iterate_extent_inodes(fs_info, path, found_key.objectid,
- extent_offset,
+ extent_item_pos,
scrub_print_warning_inode, &swarn);
}
--
1.7.3.4
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