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Diffstat (limited to 'fs/btrfs/ctree.c')
-rw-r--r--fs/btrfs/ctree.c60
1 files changed, 35 insertions, 25 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 15cbc2bf4ff..8206b390058 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1024,11 +1024,18 @@ __tree_mod_log_oldest_root(struct btrfs_fs_info *fs_info,
if (!looped && !tm)
return 0;
/*
- * we must have key remove operations in the log before the
- * replace operation.
+ * if there are no tree operation for the oldest root, we simply
+ * return it. this should only happen if that (old) root is at
+ * level 0.
*/
- BUG_ON(!tm);
+ if (!tm)
+ break;
+ /*
+ * if there's an operation that's not a root replacement, we
+ * found the oldest version of our root. normally, we'll find a
+ * MOD_LOG_KEY_REMOVE_WHILE_FREEING operation here.
+ */
if (tm->op != MOD_LOG_ROOT_REPLACE)
break;
@@ -1087,11 +1094,7 @@ __tree_mod_log_rewind(struct extent_buffer *eb, u64 time_seq,
tm->generation);
break;
case MOD_LOG_KEY_ADD:
- if (tm->slot != n - 1) {
- o_dst = btrfs_node_key_ptr_offset(tm->slot);
- o_src = btrfs_node_key_ptr_offset(tm->slot + 1);
- memmove_extent_buffer(eb, o_dst, o_src, p_size);
- }
+ /* if a move operation is needed it's in the log */
n--;
break;
case MOD_LOG_MOVE_KEYS:
@@ -1192,16 +1195,8 @@ get_old_root(struct btrfs_root *root, u64 time_seq)
}
tm = tree_mod_log_search(root->fs_info, logical, time_seq);
- /*
- * there was an item in the log when __tree_mod_log_oldest_root
- * returned. this one must not go away, because the time_seq passed to
- * us must be blocking its removal.
- */
- BUG_ON(!tm);
-
if (old_root)
- eb = alloc_dummy_extent_buffer(tm->index << PAGE_CACHE_SHIFT,
- root->nodesize);
+ eb = alloc_dummy_extent_buffer(logical, root->nodesize);
else
eb = btrfs_clone_extent_buffer(root->node);
btrfs_tree_read_unlock(root->node);
@@ -1216,7 +1211,10 @@ get_old_root(struct btrfs_root *root, u64 time_seq)
btrfs_set_header_level(eb, old_root->level);
btrfs_set_header_generation(eb, old_generation);
}
- __tree_mod_log_rewind(eb, time_seq, tm);
+ if (tm)
+ __tree_mod_log_rewind(eb, time_seq, tm);
+ else
+ WARN_ON(btrfs_header_level(eb) != 0);
extent_buffer_get(eb);
return eb;
@@ -2995,7 +2993,7 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans,
static void insert_ptr(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_path *path,
struct btrfs_disk_key *key, u64 bytenr,
- int slot, int level, int tree_mod_log)
+ int slot, int level)
{
struct extent_buffer *lower;
int nritems;
@@ -3008,7 +3006,7 @@ static void insert_ptr(struct btrfs_trans_handle *trans,
BUG_ON(slot > nritems);
BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(root));
if (slot != nritems) {
- if (tree_mod_log && level)
+ if (level)
tree_mod_log_eb_move(root->fs_info, lower, slot + 1,
slot, nritems - slot);
memmove_extent_buffer(lower,
@@ -3016,7 +3014,7 @@ static void insert_ptr(struct btrfs_trans_handle *trans,
btrfs_node_key_ptr_offset(slot),
(nritems - slot) * sizeof(struct btrfs_key_ptr));
}
- if (tree_mod_log && level) {
+ if (level) {
ret = tree_mod_log_insert_key(root->fs_info, lower, slot,
MOD_LOG_KEY_ADD);
BUG_ON(ret < 0);
@@ -3104,7 +3102,7 @@ static noinline int split_node(struct btrfs_trans_handle *trans,
btrfs_mark_buffer_dirty(split);
insert_ptr(trans, root, path, &disk_key, split->start,
- path->slots[level + 1] + 1, level + 1, 1);
+ path->slots[level + 1] + 1, level + 1);
if (path->slots[level] >= mid) {
path->slots[level] -= mid;
@@ -3641,7 +3639,7 @@ static noinline void copy_for_split(struct btrfs_trans_handle *trans,
btrfs_set_header_nritems(l, mid);
btrfs_item_key(right, &disk_key, 0);
insert_ptr(trans, root, path, &disk_key, right->start,
- path->slots[1] + 1, 1, 0);
+ path->slots[1] + 1, 1);
btrfs_mark_buffer_dirty(right);
btrfs_mark_buffer_dirty(l);
@@ -3848,7 +3846,7 @@ again:
if (mid <= slot) {
btrfs_set_header_nritems(right, 0);
insert_ptr(trans, root, path, &disk_key, right->start,
- path->slots[1] + 1, 1, 0);
+ path->slots[1] + 1, 1);
btrfs_tree_unlock(path->nodes[0]);
free_extent_buffer(path->nodes[0]);
path->nodes[0] = right;
@@ -3857,7 +3855,7 @@ again:
} else {
btrfs_set_header_nritems(right, 0);
insert_ptr(trans, root, path, &disk_key, right->start,
- path->slots[1], 1, 0);
+ path->slots[1], 1);
btrfs_tree_unlock(path->nodes[0]);
free_extent_buffer(path->nodes[0]);
path->nodes[0] = right;
@@ -5121,6 +5119,18 @@ again:
if (!path->skip_locking) {
ret = btrfs_try_tree_read_lock(next);
+ if (!ret && time_seq) {
+ /*
+ * If we don't get the lock, we may be racing
+ * with push_leaf_left, holding that lock while
+ * itself waiting for the leaf we've currently
+ * locked. To solve this situation, we give up
+ * on our lock and cycle.
+ */
+ btrfs_release_path(path);
+ cond_resched();
+ goto again;
+ }
if (!ret) {
btrfs_set_path_blocking(path);
btrfs_tree_read_lock(next);