#include "transaction.h"
#include "print-tree.h"
#include "locking.h"
+#include "volumes.h"
static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path, int level);
else
btrfs_set_header_owner(cow, new_root_objectid);
- write_extent_buffer_fsid(cow, fs_info->fsid);
+ write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid);
WARN_ON(btrfs_header_generation(buf) > trans->transid);
if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID)
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.
+ * If we are COWing a node/leaf from the extent, chunk, device or free
+ * space 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.
+ * group modifies the extent, chunk, device and free space 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)
+ root == fs_info->dev_root ||
+ root == fs_info->free_space_root)
trans->can_flush_pending_bgs = false;
cow = btrfs_alloc_tree_block(trans, root, parent_start,
else
btrfs_set_header_owner(cow, root->root_key.objectid);
- write_extent_buffer_fsid(cow, fs_info->fsid);
+ write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid);
ret = update_ref_for_cow(trans, root, buf, cow, &last_ref);
if (ret) {
*
* What is forced COW:
* when we create snapshot during committing the transaction,
- * after we've finished coping src root, we must COW the shared
+ * after we've finished copying src root, we must COW the shared
* block to ensure the metadata consistency.
*/
if (btrfs_header_generation(buf) == trans->transid &&
u64 search_start;
int ret;
+ if (test_bit(BTRFS_ROOT_DELETING, &root->state))
+ btrfs_err(fs_info,
+ "COW'ing blocks on a fs root that's being dropped");
+
if (trans->transaction != fs_info->running_transaction)
WARN(1, KERN_CRIT "trans %llu running %llu\n",
trans->transid,
root_lock = BTRFS_READ_LOCK;
if (p->search_commit_root) {
- /* The commit roots are read only so we always do read locks */
- if (p->need_commit_sem)
+ /*
+ * The commit roots are read only so we always do read locks,
+ * and we always must hold the commit_root_sem when doing
+ * searches on them, the only exception is send where we don't
+ * want to block transaction commits for a long time, so
+ * we need to clone the commit root in order to avoid races
+ * with transaction commits that create a snapshot of one of
+ * the roots used by a send operation.
+ */
+ if (p->need_commit_sem) {
down_read(&fs_info->commit_root_sem);
- b = root->commit_root;
- extent_buffer_get(b);
- level = btrfs_header_level(b);
- if (p->need_commit_sem)
+ b = btrfs_clone_extent_buffer(root->commit_root);
up_read(&fs_info->commit_root_sem);
+ if (!b)
+ return ERR_PTR(-ENOMEM);
+
+ } else {
+ b = root->commit_root;
+ extent_buffer_get(b);
+ }
+ level = btrfs_header_level(b);
/*
* Ensure that all callers have set skip_locking when
* p->search_commit_root = 1.
again:
prev_cmp = -1;
b = btrfs_search_slot_get_root(root, p, write_lock_level);
+ if (IS_ERR(b)) {
+ ret = PTR_ERR(b);
+ goto done;
+ }
while (b) {
level = btrfs_header_level(b);
/* Key greater than all keys in the leaf, right neighbor has
* enough room for it and we're not emptying our leaf to delete
* it, therefore use right neighbor to insert the new item and
- * no need to touch/dirty our left leaft. */
+ * no need to touch/dirty our left leaf. */
btrfs_tree_unlock(left);
free_extent_buffer(left);
path->nodes[0] = right;
git.samba.org / sfrench / cifs-2.6.git / blobdiff