summaryrefslogtreecommitdiff
path: root/btrfsck.c
diff options
context:
space:
mode:
Diffstat (limited to 'btrfsck.c')
-rw-r--r--btrfsck.c244
1 files changed, 228 insertions, 16 deletions
diff --git a/btrfsck.c b/btrfsck.c
index d13658e7..e8674925 100644
--- a/btrfsck.c
+++ b/btrfsck.c
@@ -26,6 +26,7 @@
#include "disk-io.h"
#include "print-tree.h"
#include "transaction.h"
+#include "list.h"
static u64 bytes_used = 0;
static u64 total_csum_bytes = 0;
@@ -34,12 +35,22 @@ static u64 btree_space_waste = 0;
static u64 data_bytes_allocated = 0;
static u64 data_bytes_referenced = 0;
+struct extent_backref {
+ struct list_head list;
+ u64 root;
+ u64 generation;
+ u64 owner;
+ u64 offset;
+ int found_extent_tree;
+ int found_ref;
+};
+
struct extent_record {
+ struct list_head backrefs;
struct cache_extent cache;
struct btrfs_disk_key parent_key;
u64 start;
u64 nr;
- u64 owner;
u32 refs;
u32 extent_item_refs;
int checked;
@@ -120,12 +131,74 @@ static int check_leaf(struct btrfs_root *root,
return 0;
}
+static int all_backpointers_checked(struct extent_record *rec, int print_errs)
+{
+ struct list_head *cur = rec->backrefs.next;
+ struct extent_backref *back;
+ u32 found = 0;
+ int err = 0;
+
+ while(cur != &rec->backrefs) {
+ back = list_entry(cur, struct extent_backref, list);
+ cur = cur->next;
+ if (!back->found_extent_tree) {
+ err = 1;
+ if (!print_errs)
+ goto out;
+ fprintf(stderr, "Backref %llu [%llu %llu %llu %llu] "
+ "not found in extent tree\n",
+ (unsigned long long)rec->start,
+ (unsigned long long)back->root,
+ (unsigned long long)back->generation,
+ (unsigned long long)back->owner,
+ (unsigned long long)back->offset);
+ }
+ if (!back->found_ref) {
+ err = 1;
+ if (!print_errs)
+ goto out;
+ fprintf(stderr, "Backref %llu [%llu %llu %llu %llu] "
+ "not referenced\n",
+ (unsigned long long)rec->start,
+ (unsigned long long)back->root,
+ (unsigned long long)back->generation,
+ (unsigned long long)back->owner,
+ (unsigned long long)back->offset);
+ }
+ found++;
+ }
+ if (found != rec->refs) {
+ err = 1;
+ if (!print_errs)
+ goto out;
+ fprintf(stderr, "Incorrect backref count on %llu found %u "
+ "wanted %u\n", (unsigned long long)rec->start,
+ found, rec->refs);
+ }
+out:
+ return err;
+}
+
+static int free_all_backrefs(struct extent_record *rec)
+{
+ struct extent_backref *back;
+ struct list_head *cur;
+ while (!list_empty(&rec->backrefs)) {
+ cur = rec->backrefs.next;
+ back = list_entry(cur, struct extent_backref, list);
+ list_del(cur);
+ free(back);
+ }
+ return 0;
+}
+
static int maybe_free_extent_rec(struct cache_tree *extent_cache,
struct extent_record *rec)
{
if (rec->checked && rec->extent_item_refs == rec->refs &&
- rec->refs > 0) {
+ rec->refs > 0 && !all_backpointers_checked(rec, 0)) {
remove_cache_extent(extent_cache, &rec->cache);
+ free_all_backrefs(rec);
free(rec);
}
return 0;
@@ -154,10 +227,45 @@ static int check_block(struct btrfs_root *root,
return ret;
}
+static struct extent_backref *find_backref(struct extent_record *rec,
+ u64 root, u64 gen,
+ u64 owner, u64 owner_offset)
+{
+ struct list_head *cur = rec->backrefs.next;
+ struct extent_backref *back;
+
+ while(cur != &rec->backrefs) {
+ back = list_entry(cur, struct extent_backref, list);
+ cur = cur->next;
+ if (back->root != root || gen != back->generation)
+ continue;
+ if (owner < BTRFS_FIRST_FREE_OBJECTID)
+ return back;
+ if (owner != back->owner || owner_offset != back->offset)
+ continue;
+ return back;
+ }
+ return NULL;
+}
+
+static struct extent_backref *alloc_backref(struct extent_record *rec,
+ u64 root, u64 gen, u64 owner,
+ u64 owner_offset)
+{
+ struct extent_backref *ref = malloc(sizeof(*ref));
+ ref->root = root;
+ ref->generation = gen;
+ ref->owner = owner;
+ ref->offset = owner_offset;
+ ref->found_extent_tree = 0;
+ ref->found_ref = 0;
+ list_add_tail(&ref->list, &rec->backrefs);
+ return ref;
+}
+
static int add_extent_rec(struct cache_tree *extent_cache,
struct btrfs_disk_key *parent_key,
- u64 ref, u64 start,
- u64 nr, u64 owner,
+ u64 ref, u64 start, u64 nr,
u32 extent_item_refs, int inc_ref, int set_checked)
{
struct extent_record *rec;
@@ -169,6 +277,9 @@ static int add_extent_rec(struct cache_tree *extent_cache,
rec = container_of(cache, struct extent_record, cache);
if (inc_ref)
rec->refs++;
+ if (rec->nr == 1)
+ rec->nr = nr;
+
if (start != rec->start) {
fprintf(stderr, "warning, start mismatch %llu %llu\n",
(unsigned long long)rec->start,
@@ -177,12 +288,21 @@ static int add_extent_rec(struct cache_tree *extent_cache,
}
if (extent_item_refs) {
if (rec->extent_item_refs) {
- fprintf(stderr, "block %llu rec extent_item_refs %u, passed %u\n", (unsigned long long)start, rec->extent_item_refs, extent_item_refs);
+ fprintf(stderr, "block %llu rec "
+ "extent_item_refs %u, passed %u\n",
+ (unsigned long long)start,
+ rec->extent_item_refs,
+ extent_item_refs);
}
rec->extent_item_refs = extent_item_refs;
}
if (set_checked)
rec->checked = 1;
+
+ if (parent_key)
+ memcpy(&rec->parent_key, parent_key,
+ sizeof(*parent_key));
+
maybe_free_extent_rec(extent_cache, rec);
return ret;
}
@@ -191,8 +311,8 @@ static int add_extent_rec(struct cache_tree *extent_cache,
extent_item_refs = 0;
rec->start = start;
rec->nr = nr;
- rec->owner = owner;
rec->checked = 0;
+ INIT_LIST_HEAD(&rec->backrefs);
if (inc_ref)
rec->refs = 1;
@@ -219,6 +339,60 @@ static int add_extent_rec(struct cache_tree *extent_cache,
return ret;
}
+static int add_backref(struct cache_tree *extent_cache, u64 bytenr,
+ u64 root, u64 gen, u64 owner, u64 owner_offset,
+ int found_ref)
+{
+ struct extent_record *rec;
+ struct extent_backref *back;
+ struct cache_extent *cache;
+
+ if (root < BTRFS_FS_TREE_OBJECTID)
+ gen = 0;
+
+ cache = find_cache_extent(extent_cache, bytenr, 1);
+ if (!cache) {
+ add_extent_rec(extent_cache, NULL, 0, bytenr, 1, 0, 0, 0);
+ cache = find_cache_extent(extent_cache, bytenr, 1);
+ if (!cache)
+ abort();
+ }
+
+ rec = container_of(cache, struct extent_record, cache);
+ if (rec->start != bytenr) {
+ abort();
+ }
+ back = find_backref(rec, root, gen, owner, owner_offset);
+ if (!back)
+ back = alloc_backref(rec, root, gen, owner, owner_offset);
+
+ if (found_ref) {
+ if (back->found_ref) {
+ fprintf(stderr, "Back ref already exists for %llu "
+ "root %llu gen %llu owner %llu offset %llu\n",
+ (unsigned long long)bytenr,
+ (unsigned long long)root,
+ (unsigned long long)gen,
+ (unsigned long long)owner,
+ (unsigned long long)owner_offset);
+ }
+ back->found_ref = 1;
+ } else {
+ if (back->found_extent_tree) {
+ fprintf(stderr, "Extent back ref already exists "
+ "for %llu root %llu gen %llu owner %llu "
+ "offset %llu\n", (unsigned long long)bytenr,
+ (unsigned long long)root,
+ (unsigned long long)gen,
+ (unsigned long long)owner,
+ (unsigned long long)owner_offset);
+ }
+ back->found_extent_tree = 1;
+ }
+ return 0;
+}
+
+
static int add_pending(struct cache_tree *pending,
struct cache_tree *seen, u64 bytenr, u32 size)
{
@@ -314,6 +488,7 @@ static int run_next_block(struct btrfs_root *root,
int ret;
int i;
int nritems;
+ struct btrfs_extent_ref *ref;
struct btrfs_leaf *leaf;
struct btrfs_node *node;
struct btrfs_disk_key *disk_key;
@@ -375,14 +550,12 @@ static int run_next_block(struct btrfs_root *root,
BTRFS_EXTENT_ITEM_KEY) {
struct btrfs_key found;
struct btrfs_extent_item *ei;
- btrfs_disk_key_to_cpu(&found,
- &leaf->items[i].key);
+ btrfs_disk_key_to_cpu(&found, disk_key);
ei = btrfs_item_ptr(leaf, i,
struct btrfs_extent_item);
add_extent_rec(extent_cache, NULL, 0,
found.objectid,
found.offset,
- 0,
btrfs_extent_refs(ei), 0, 0);
continue;
}
@@ -406,7 +579,20 @@ static int run_next_block(struct btrfs_root *root,
#endif
continue;
}
- if (btrfs_disk_key_type(&leaf->items[i].key) !=
+ if (btrfs_disk_key_type(disk_key) ==
+ BTRFS_EXTENT_REF_KEY) {
+ ref = btrfs_item_ptr(leaf, i,
+ struct btrfs_extent_ref);
+
+ add_backref(extent_cache,
+ btrfs_disk_key_objectid(disk_key),
+ btrfs_ref_root(ref),
+ btrfs_ref_generation(ref),
+ btrfs_ref_objectid(ref),
+ btrfs_ref_offset(ref), 0);
+ continue;
+ }
+ if (btrfs_disk_key_type(disk_key) !=
BTRFS_EXTENT_DATA_KEY)
continue;
fi = btrfs_item_ptr(leaf, i,
@@ -424,8 +610,13 @@ static int run_next_block(struct btrfs_root *root,
ret = add_extent_rec(extent_cache, NULL, bytenr,
btrfs_file_extent_disk_bytenr(fi),
btrfs_file_extent_disk_num_bytes(fi),
- btrfs_disk_key_objectid(&leaf->items[i].key),
0, 1, 1);
+ add_backref(extent_cache,
+ btrfs_file_extent_disk_bytenr(fi),
+ btrfs_header_owner(&leaf->header),
+ btrfs_header_generation(&leaf->header),
+ btrfs_disk_key_objectid(disk_key),
+ btrfs_disk_key_offset(disk_key), 1);
BUG_ON(ret);
}
} else {
@@ -438,9 +629,15 @@ static int run_next_block(struct btrfs_root *root,
ret = add_extent_rec(extent_cache,
&node->ptrs[i].key,
bytenr, ptr, size,
- btrfs_header_owner(&node->header),
0, 1, 0);
BUG_ON(ret);
+
+ add_backref(extent_cache, ptr,
+ btrfs_header_owner(&node->header),
+ btrfs_header_generation(&node->header),
+ level - 1,
+ btrfs_disk_key_objectid(&node->ptrs[i].key), 1);
+
if (level > 1) {
add_pending(nodes, seen, ptr, size);
} else {
@@ -462,14 +659,18 @@ static int add_root_to_pending(struct btrfs_buffer *buf,
struct cache_tree *pending,
struct cache_tree *seen,
struct cache_tree *reada,
- struct cache_tree *nodes)
+ struct cache_tree *nodes, u64 root_objectid)
{
if (btrfs_header_level(&buf->node.header) > 0)
add_pending(nodes, seen, buf->bytenr, buf->size);
else
add_pending(pending, seen, buf->bytenr, buf->size);
add_extent_rec(extent_cache, NULL, 0, buf->bytenr, buf->size,
- btrfs_header_owner(&buf->node.header), 0, 1, 0);
+ 0, 1, 0);
+
+ add_backref(extent_cache, buf->bytenr, root_objectid,
+ btrfs_header_generation(&buf->node.header),
+ btrfs_header_level(&buf->node.header), 0, 1);
return 0;
}
@@ -494,7 +695,15 @@ int check_extent_refs(struct btrfs_root *root,
rec->refs);
err = 1;
}
+ if (all_backpointers_checked(rec, 1)) {
+ fprintf(stderr, "backpointer mismatch on [%llu %llu]\n",
+ (unsigned long long)rec->start,
+ (unsigned long long)rec->nr);
+
+ err = 1;
+ }
remove_cache_extent(extent_cache, cache);
+ free_all_backrefs(rec);
free(rec);
}
return err;
@@ -536,7 +745,8 @@ int main(int ac, char **av) {
}
add_root_to_pending(root->fs_info->tree_root->node, bits, bits_nr,
- &extent_cache, &pending, &seen, &reada, &nodes);
+ &extent_cache, &pending, &seen, &reada, &nodes,
+ root->fs_info->tree_root->root_key.objectid);
btrfs_init_path(&path);
key.offset = 0;
@@ -559,6 +769,7 @@ int main(int ac, char **av) {
&leaf->items[path.slots[0]].key);
if (btrfs_key_type(&found_key) == BTRFS_ROOT_ITEM_KEY) {
struct btrfs_buffer *buf;
+
ri = btrfs_item_ptr(leaf, path.slots[0],
struct btrfs_root_item);
buf = read_tree_block(root->fs_info->tree_root,
@@ -566,7 +777,8 @@ int main(int ac, char **av) {
btrfs_level_size(root,
btrfs_root_level(ri)));
add_root_to_pending(buf, bits, bits_nr, &extent_cache,
- &pending, &seen, &reada, &nodes);
+ &pending, &seen, &reada, &nodes,
+ found_key.objectid);
btrfs_block_release(root->fs_info->tree_root, buf);
}
path.slots[0]++;