Commit f6167514 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 

Pull btrfs fixes from Chris Mason:
 "My patch fixes the btrfs list_head abuse that we tracked down during
  Dave Jones' memory corruption investigation. With both Jens and my
  patches in place, I'm no longer able to trigger problems.

  Filipe is fixing a difficult old bug between snapshots, balance and
  send. Dave is cooking a few more for the next rc, but these are tested
  and ready"

* 'for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: fix races on root_log_ctx lists
  btrfs: fix incremental send failure caused by balance
parents 2cd0b50a 570dd450

fs/btrfs/send.c

+58 −0
Original line number Original line Diff line number Diff line
@@ -5805,6 +5805,64 @@ static int changed_extent(struct send_ctx *sctx, 
	int ret = 0;

	int ret = 0;





	if (sctx->cur_ino != sctx->cmp_key->objectid) {

	if (sctx->cur_ino != sctx->cmp_key->objectid) {



		if (result == BTRFS_COMPARE_TREE_CHANGED) {

			struct extent_buffer *leaf_l;

			struct extent_buffer *leaf_r;

			struct btrfs_file_extent_item *ei_l;

			struct btrfs_file_extent_item *ei_r;



			leaf_l = sctx->left_path->nodes[0];

			leaf_r = sctx->right_path->nodes[0];

			ei_l = btrfs_item_ptr(leaf_l,

					      sctx->left_path->slots[0],

					      struct btrfs_file_extent_item);

			ei_r = btrfs_item_ptr(leaf_r,

					      sctx->right_path->slots[0],

					      struct btrfs_file_extent_item);



			/*

			 * We may have found an extent item that has changed

			 * only its disk_bytenr field and the corresponding

			 * inode item was not updated. This case happens due to

			 * very specific timings during relocation when a leaf

			 * that contains file extent items is COWed while

			 * relocation is ongoing and its in the stage where it

			 * updates data pointers. So when this happens we can

			 * safely ignore it since we know it's the same extent,

			 * but just at different logical and physical locations

			 * (when an extent is fully replaced with a new one, we

			 * know the generation number must have changed too,

			 * since snapshot creation implies committing the current

			 * transaction, and the inode item must have been updated

			 * as well).

			 * This replacement of the disk_bytenr happens at

			 * relocation.c:replace_file_extents() through

			 * relocation.c:btrfs_reloc_cow_block().

			 */

			if (btrfs_file_extent_generation(leaf_l, ei_l) ==

			    btrfs_file_extent_generation(leaf_r, ei_r) &&

			    btrfs_file_extent_ram_bytes(leaf_l, ei_l) ==

			    btrfs_file_extent_ram_bytes(leaf_r, ei_r) &&

			    btrfs_file_extent_compression(leaf_l, ei_l) ==

			    btrfs_file_extent_compression(leaf_r, ei_r) &&

			    btrfs_file_extent_encryption(leaf_l, ei_l) ==

			    btrfs_file_extent_encryption(leaf_r, ei_r) &&

			    btrfs_file_extent_other_encoding(leaf_l, ei_l) ==

			    btrfs_file_extent_other_encoding(leaf_r, ei_r) &&

			    btrfs_file_extent_type(leaf_l, ei_l) ==

			    btrfs_file_extent_type(leaf_r, ei_r) &&

			    btrfs_file_extent_disk_bytenr(leaf_l, ei_l) !=

			    btrfs_file_extent_disk_bytenr(leaf_r, ei_r) &&

			    btrfs_file_extent_disk_num_bytes(leaf_l, ei_l) ==

			    btrfs_file_extent_disk_num_bytes(leaf_r, ei_r) &&

			    btrfs_file_extent_offset(leaf_l, ei_l) ==

			    btrfs_file_extent_offset(leaf_r, ei_r) &&

			    btrfs_file_extent_num_bytes(leaf_l, ei_l) ==

			    btrfs_file_extent_num_bytes(leaf_r, ei_r))

				return 0;

		}



		inconsistent_snapshot_error(sctx, result, "extent");

		inconsistent_snapshot_error(sctx, result, "extent");

		return -EIO;

		return -EIO;

	}

	}

fs/btrfs/tree-log.c

+6 −14
Original line number Original line Diff line number Diff line
@@ -2713,14 +2713,12 @@ static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root, 
					     int index, int error)

					     int index, int error)

{

{

	struct btrfs_log_ctx *ctx;

	struct btrfs_log_ctx *ctx;

	struct btrfs_log_ctx *safe;





	if (!error) {

	list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) {

		INIT_LIST_HEAD(&root->log_ctxs[index]);

		list_del_init(&ctx->list);

		return;

	}



	list_for_each_entry(ctx, &root->log_ctxs[index], list)

		ctx->log_ret = error;

		ctx->log_ret = error;

	}





	INIT_LIST_HEAD(&root->log_ctxs[index]);

	INIT_LIST_HEAD(&root->log_ctxs[index]);

}

}
@@ -2961,13 +2959,9 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans, 
	mutex_unlock(&root->log_mutex);

	mutex_unlock(&root->log_mutex);





out_wake_log_root:

out_wake_log_root:

	/*

	mutex_lock(&log_root_tree->log_mutex);

	 * We needn't get log_mutex here because we are sure all

	 * the other tasks are blocked.

	 */

	btrfs_remove_all_log_ctxs(log_root_tree, index2, ret);

	btrfs_remove_all_log_ctxs(log_root_tree, index2, ret);





	mutex_lock(&log_root_tree->log_mutex);

	log_root_tree->log_transid_committed++;

	log_root_tree->log_transid_committed++;

	atomic_set(&log_root_tree->log_commit[index2], 0);

	atomic_set(&log_root_tree->log_commit[index2], 0);

	mutex_unlock(&log_root_tree->log_mutex);

	mutex_unlock(&log_root_tree->log_mutex);
@@ -2978,10 +2972,8 @@ out_wake_log_root: 
	if (waitqueue_active(&log_root_tree->log_commit_wait[index2]))

	if (waitqueue_active(&log_root_tree->log_commit_wait[index2]))

		wake_up(&log_root_tree->log_commit_wait[index2]);

		wake_up(&log_root_tree->log_commit_wait[index2]);

out:

out:

	/* See above. */

	btrfs_remove_all_log_ctxs(root, index1, ret);



	mutex_lock(&root->log_mutex);

	mutex_lock(&root->log_mutex);

	btrfs_remove_all_log_ctxs(root, index1, ret);

	root->log_transid_committed++;

	root->log_transid_committed++;

	atomic_set(&root->log_commit[index1], 0);

	atomic_set(&root->log_commit[index1], 0);

	mutex_unlock(&root->log_mutex);

	mutex_unlock(&root->log_mutex);

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