#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
*/
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]);
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)
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;
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);
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;
}
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;
}
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);
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: %lu, "
+ "constructed so far: %s\n",
+ (unsigned long)(fspath_min - fspath), fspath_min);
++ipath->fspath->elem_missed;
ipath->fspath->bytes_missing += fspath_min - fspath;
ipath->fspath->bytes_left = 0;
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