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Diffstat (limited to 'fs/btrfs/ctree.c')
-rw-r--r--fs/btrfs/ctree.c85
1 files changed, 28 insertions, 57 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index d436fb4c002e..539901fb5165 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -52,42 +52,6 @@ noinline void btrfs_set_path_blocking(struct btrfs_path *p)
}
}
-/*
- * reset all the locked nodes in the patch to spinning locks.
- *
- * held is used to keep lockdep happy, when lockdep is enabled
- * we set held to a blocking lock before we go around and
- * retake all the spinlocks in the path. You can safely use NULL
- * for held
- */
-noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
- struct extent_buffer *held, int held_rw)
-{
- int i;
-
- if (held) {
- btrfs_set_lock_blocking_rw(held, held_rw);
- if (held_rw == BTRFS_WRITE_LOCK)
- held_rw = BTRFS_WRITE_LOCK_BLOCKING;
- else if (held_rw == BTRFS_READ_LOCK)
- held_rw = BTRFS_READ_LOCK_BLOCKING;
- }
- btrfs_set_path_blocking(p);
-
- for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) {
- if (p->nodes[i] && p->locks[i]) {
- btrfs_clear_lock_blocking_rw(p->nodes[i], p->locks[i]);
- if (p->locks[i] == BTRFS_WRITE_LOCK_BLOCKING)
- p->locks[i] = BTRFS_WRITE_LOCK;
- else if (p->locks[i] == BTRFS_READ_LOCK_BLOCKING)
- p->locks[i] = BTRFS_READ_LOCK;
- }
- }
-
- if (held)
- btrfs_clear_lock_blocking_rw(held, held_rw);
-}
-
/* this also releases the path */
void btrfs_free_path(struct btrfs_path *p)
{
@@ -207,7 +171,7 @@ static void add_root_to_dirty_list(struct btrfs_root *root)
spin_lock(&fs_info->trans_lock);
if (!test_and_set_bit(BTRFS_ROOT_DIRTY, &root->state)) {
/* Want the extent tree to be the last on the list */
- if (root->objectid == BTRFS_EXTENT_TREE_OBJECTID)
+ if (root->root_key.objectid == BTRFS_EXTENT_TREE_OBJECTID)
list_move_tail(&root->dirty_list,
&fs_info->dirty_cowonly_roots);
else
@@ -1050,9 +1014,26 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
if ((root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && parent)
parent_start = parent->start;
+ /*
+ * If we are COWing a node/leaf from the extent, chunk or device trees,
+ * make sure that we do not finish block group creation of pending block
+ * groups. We do this to avoid a deadlock.
+ * COWing can result in allocation of a new chunk, and flushing pending
+ * block groups (btrfs_create_pending_block_groups()) can be triggered
+ * when finishing allocation of a new chunk. Creation of a pending block
+ * group modifies the extent, chunk and device trees, therefore we could
+ * deadlock with ourselves since we are holding a lock on an extent
+ * buffer that btrfs_create_pending_block_groups() may try to COW later.
+ */
+ if (root == fs_info->extent_root ||
+ root == fs_info->chunk_root ||
+ root == fs_info->dev_root)
+ trans->can_flush_pending_bgs = false;
+
cow = btrfs_alloc_tree_block(trans, root, parent_start,
root->root_key.objectid, &disk_key, level,
search_start, empty_size);
+ trans->can_flush_pending_bgs = true;
if (IS_ERR(cow))
return PTR_ERR(cow);
@@ -1306,7 +1287,6 @@ tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
}
}
- btrfs_clear_path_blocking(path, NULL, BTRFS_READ_LOCK);
btrfs_tree_read_unlock_blocking(eb);
free_extent_buffer(eb);
@@ -1815,8 +1795,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
int orig_slot = path->slots[level];
u64 orig_ptr;
- if (level == 0)
- return 0;
+ ASSERT(level > 0);
mid = path->nodes[level];
@@ -2483,7 +2462,6 @@ setup_nodes_for_search(struct btrfs_trans_handle *trans,
btrfs_set_path_blocking(p);
reada_for_balance(fs_info, p, level);
sret = split_node(trans, root, p, level);
- btrfs_clear_path_blocking(p, NULL, 0);
BUG_ON(sret > 0);
if (sret) {
@@ -2504,7 +2482,6 @@ setup_nodes_for_search(struct btrfs_trans_handle *trans,
btrfs_set_path_blocking(p);
reada_for_balance(fs_info, p, level);
sret = balance_level(trans, root, p, level);
- btrfs_clear_path_blocking(p, NULL, 0);
if (sret) {
ret = sret;
@@ -2789,7 +2766,10 @@ again:
}
cow_done:
p->nodes[level] = b;
- btrfs_clear_path_blocking(p, NULL, 0);
+ /*
+ * Leave path with blocking locks to avoid massive
+ * lock context switch, this is made on purpose.
+ */
/*
* we have a lock on b and as long as we aren't changing
@@ -2871,8 +2851,6 @@ cow_done:
if (!err) {
btrfs_set_path_blocking(p);
btrfs_tree_lock(b);
- btrfs_clear_path_blocking(p, b,
- BTRFS_WRITE_LOCK);
}
p->locks[level] = BTRFS_WRITE_LOCK;
} else {
@@ -2880,8 +2858,6 @@ cow_done:
if (!err) {
btrfs_set_path_blocking(p);
btrfs_tree_read_lock(b);
- btrfs_clear_path_blocking(p, b,
- BTRFS_READ_LOCK);
}
p->locks[level] = BTRFS_READ_LOCK;
}
@@ -2900,7 +2876,6 @@ cow_done:
btrfs_set_path_blocking(p);
err = split_leaf(trans, root, key,
p, ins_len, ret == 0);
- btrfs_clear_path_blocking(p, NULL, 0);
BUG_ON(err > 0);
if (err) {
@@ -2910,7 +2885,7 @@ cow_done:
}
if (!p->search_for_split)
unlock_up(p, level, lowest_unlock,
- min_write_lock_level, &write_lock_level);
+ min_write_lock_level, NULL);
goto done;
}
}
@@ -2961,13 +2936,16 @@ int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key,
again:
b = get_old_root(root, time_seq);
+ if (!b) {
+ ret = -EIO;
+ goto done;
+ }
level = btrfs_header_level(b);
p->locks[level] = BTRFS_READ_LOCK;
while (b) {
level = btrfs_header_level(b);
p->nodes[level] = b;
- btrfs_clear_path_blocking(p, NULL, 0);
/*
* we have a lock on b and as long as we aren't changing
@@ -3013,8 +2991,6 @@ again:
if (!err) {
btrfs_set_path_blocking(p);
btrfs_tree_read_lock(b);
- btrfs_clear_path_blocking(p, b,
- BTRFS_READ_LOCK);
}
b = tree_mod_log_rewind(fs_info, p, b, time_seq);
if (!b) {
@@ -5198,7 +5174,6 @@ find_next_key:
path->locks[level - 1] = BTRFS_READ_LOCK;
path->nodes[level - 1] = cur;
unlock_up(path, level, 1, 0, NULL);
- btrfs_clear_path_blocking(path, NULL, 0);
}
out:
path->keep_locks = keep_locks;
@@ -5783,8 +5758,6 @@ again:
if (!ret) {
btrfs_set_path_blocking(path);
btrfs_tree_read_lock(next);
- btrfs_clear_path_blocking(path, next,
- BTRFS_READ_LOCK);
}
next_rw_lock = BTRFS_READ_LOCK;
}
@@ -5820,8 +5793,6 @@ again:
if (!ret) {
btrfs_set_path_blocking(path);
btrfs_tree_read_lock(next);
- btrfs_clear_path_blocking(path, next,
- BTRFS_READ_LOCK);
}
next_rw_lock = BTRFS_READ_LOCK;
}
generated by cgit v1.2.3 (git 2.39.0) at 2024-07-28 06:16:58 +0300