From 3ae36b3b0f13326df8b38ff4a4df1ce47fccd417 Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Tue, 25 Jul 2017 16:51:35 -0400 Subject: btrfs-progs: backref: push state tracking into a helper structure Eventually, we'll have several lists and trees, as well as some statistics. Signed-off-by: Jeff Mahoney Signed-off-by: David Sterba --- backref.c | 75 ++++++++++++++++++++++++++++++++++++++------------------------- 1 file changed, 45 insertions(+), 30 deletions(-) diff --git a/backref.c b/backref.c index afd14235..127951c5 100644 --- a/backref.c +++ b/backref.c @@ -130,6 +130,15 @@ struct __prelim_ref { u64 wanted_disk_byte; }; +struct pref_state { + struct list_head pending; +}; + +static void init_pref_state(struct pref_state *prefstate) +{ + INIT_LIST_HEAD(&prefstate->pending); +} + /* * the rules for all callers of this function are: * - obtaining the parent is the goal @@ -169,11 +178,12 @@ struct __prelim_ref { * block might help in merging entries to gain some speed. */ -static int __add_prelim_ref(struct list_head *head, u64 root_id, +static int __add_prelim_ref(struct pref_state *prefstate, u64 root_id, struct btrfs_key *key, int level, u64 parent, u64 wanted_disk_byte, int count, gfp_t gfp_mask) { + struct list_head *head = &prefstate->pending; struct __prelim_ref *ref; if (root_id == BTRFS_DATA_RELOC_TREE_OBJECTID) @@ -345,10 +355,11 @@ out: * resolve all indirect backrefs from the list */ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info, + struct pref_state *prefstate, struct btrfs_path *path, u64 time_seq, - struct list_head *head, const u64 *extent_item_pos, u64 total_refs) { + struct list_head *head = &prefstate->pending; int err; int ret = 0; struct __prelim_ref *ref; @@ -436,8 +447,9 @@ static inline int ref_for_same_block(struct __prelim_ref *ref1, * read tree blocks and add keys where required. */ static int __add_missing_keys(struct btrfs_fs_info *fs_info, - struct list_head *head) + struct pref_state *prefstate) { + struct list_head *head = &prefstate->pending; struct list_head *pos; struct extent_buffer *eb; @@ -474,8 +486,9 @@ static int __add_missing_keys(struct btrfs_fs_info *fs_info, * having a parent). * mode = 2: merge identical parents */ -static void __merge_refs(struct list_head *head, int mode) +static void __merge_refs(struct pref_state *prefstate, int mode) { + struct list_head *head = &prefstate->pending; struct list_head *pos1; list_for_each(pos1, head) { @@ -526,9 +539,9 @@ static void __merge_refs(struct list_head *head, int mode) * add all inline backrefs for bytenr to the list */ static int __add_inline_refs(struct btrfs_fs_info *fs_info, + struct pref_state *prefstate, struct btrfs_path *path, u64 bytenr, - int *info_level, struct list_head *prefs, - u64 *total_refs) + int *info_level, u64 *total_refs) { int ret = 0; int slot; @@ -540,7 +553,6 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, struct btrfs_extent_item *ei; u64 flags; u64 item_size; - /* * enumerate all inline refs */ @@ -583,7 +595,7 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, switch (type) { case BTRFS_SHARED_BLOCK_REF_KEY: - ret = __add_prelim_ref(prefs, 0, NULL, + ret = __add_prelim_ref(prefstate, 0, NULL, *info_level + 1, offset, bytenr, 1, GFP_NOFS); break; @@ -593,12 +605,12 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, 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, + ret = __add_prelim_ref(prefstate, 0, NULL, 0, offset, bytenr, count, GFP_NOFS); break; } case BTRFS_TREE_BLOCK_REF_KEY: - ret = __add_prelim_ref(prefs, offset, NULL, + ret = __add_prelim_ref(prefstate, offset, NULL, *info_level + 1, 0, bytenr, 1, GFP_NOFS); break; @@ -614,7 +626,7 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, 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, + ret = __add_prelim_ref(prefstate, root, &key, 0, 0, bytenr, count, GFP_NOFS); break; } @@ -633,8 +645,9 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info, * add all non-inline backrefs for bytenr to the list */ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, + struct pref_state *prefstate, struct btrfs_path *path, u64 bytenr, - int info_level, struct list_head *prefs) + int info_level) { struct btrfs_root *extent_root = fs_info->extent_root; int ret; @@ -664,7 +677,7 @@ 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, + ret = __add_prelim_ref(prefstate, 0, NULL, info_level + 1, key.offset, bytenr, 1, GFP_NOFS); break; @@ -675,12 +688,12 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, 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, + ret = __add_prelim_ref(prefstate, 0, NULL, 0, key.offset, bytenr, count, GFP_NOFS); break; } case BTRFS_TREE_BLOCK_REF_KEY: - ret = __add_prelim_ref(prefs, key.offset, NULL, + ret = __add_prelim_ref(prefstate, key.offset, NULL, info_level + 1, 0, bytenr, 1, GFP_NOFS); break; @@ -697,7 +710,7 @@ 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); root = btrfs_extent_data_ref_root(leaf, dref); - ret = __add_prelim_ref(prefs, root, &key, 0, 0, + ret = __add_prelim_ref(prefstate, root, &key, 0, 0, bytenr, count, GFP_NOFS); break; } @@ -729,12 +742,12 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, struct btrfs_path *path; int info_level = 0; int ret; - struct list_head prefs; + struct pref_state prefstate; struct __prelim_ref *ref; struct extent_inode_elem *eie = NULL; u64 total_refs = 0; - INIT_LIST_HEAD(&prefs); + init_pref_state(&prefstate); key.objectid = bytenr; key.offset = (u64)-1; @@ -763,34 +776,35 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, if (key.objectid == bytenr && (key.type == BTRFS_EXTENT_ITEM_KEY || key.type == BTRFS_METADATA_ITEM_KEY)) { - ret = __add_inline_refs(fs_info, path, bytenr, - &info_level, &prefs, + ret = __add_inline_refs(fs_info, &prefstate, path, + bytenr, &info_level, &total_refs); if (ret) goto out; - ret = __add_keyed_refs(fs_info, path, bytenr, - info_level, &prefs); + ret = __add_keyed_refs(fs_info, &prefstate, path, + bytenr, info_level); if (ret) goto out; } } btrfs_release_path(path); - ret = __add_missing_keys(fs_info, &prefs); + ret = __add_missing_keys(fs_info, &prefstate); if (ret) goto out; - __merge_refs(&prefs, 1); + __merge_refs(&prefstate, 1); - ret = __resolve_indirect_refs(fs_info, path, time_seq, &prefs, + ret = __resolve_indirect_refs(fs_info, &prefstate, path, time_seq, extent_item_pos, total_refs); if (ret) goto out; - __merge_refs(&prefs, 2); + __merge_refs(&prefstate, 2); - while (!list_empty(&prefs)) { - ref = list_first_entry(&prefs, struct __prelim_ref, list); + while (!list_empty(&prefstate.pending)) { + ref = list_first_entry(&prefstate.pending, + struct __prelim_ref, list); WARN_ON(ref->count < 0); if (roots && ref->count && ref->root_id && ref->parent == 0) { /* no parent == root of tree */ @@ -839,8 +853,9 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, out: btrfs_free_path(path); - while (!list_empty(&prefs)) { - ref = list_first_entry(&prefs, struct __prelim_ref, list); + while (!list_empty(&prefstate.pending)) { + ref = list_first_entry(&prefstate.pending, + struct __prelim_ref, list); list_del(&ref->list); kfree(ref); } -- cgit v1.2.3