Linux-libre 4.3.2-gnu

1 files changed, 280 insertions, 64 deletions

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 9c45431e6..1bbaace73 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -140,55 +140,46 @@ static int start_log_trans(struct btrfs_trans_handle *trans,
 			   struct btrfs_root *root,
 			   struct btrfs_log_ctx *ctx)
 {
-	int index;
-	int ret;
+	int ret = 0;
 
 	mutex_lock(&root->log_mutex);
+
 	if (root->log_root) {
 		if (btrfs_need_log_full_commit(root->fs_info, trans)) {
 			ret = -EAGAIN;
 			goto out;
 		}
+
 		if (!root->log_start_pid) {
-			root->log_start_pid = current->pid;
 			clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
+			root->log_start_pid = current->pid;
 		} else if (root->log_start_pid != current->pid) {
 			set_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
 		}
+	} else {
+		mutex_lock(&root->fs_info->tree_log_mutex);
+		if (!root->fs_info->log_root_tree)
+			ret = btrfs_init_log_root_tree(trans, root->fs_info);
+		mutex_unlock(&root->fs_info->tree_log_mutex);
+		if (ret)
+			goto out;
 
-		atomic_inc(&root->log_batch);
-		atomic_inc(&root->log_writers);
-		if (ctx) {
-			index = root->log_transid % 2;
-			list_add_tail(&ctx->list, &root->log_ctxs[index]);
-			ctx->log_transid = root->log_transid;
-		}
-		mutex_unlock(&root->log_mutex);
-		return 0;
-	}
-
-	ret = 0;
-	mutex_lock(&root->fs_info->tree_log_mutex);
-	if (!root->fs_info->log_root_tree)
-		ret = btrfs_init_log_root_tree(trans, root->fs_info);
-	mutex_unlock(&root->fs_info->tree_log_mutex);
-	if (ret)
-		goto out;
-
-	if (!root->log_root) {
 		ret = btrfs_add_log_tree(trans, root);
 		if (ret)
 			goto out;
+
+		clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
+		root->log_start_pid = current->pid;
 	}
-	clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
-	root->log_start_pid = current->pid;
+
 	atomic_inc(&root->log_batch);
 	atomic_inc(&root->log_writers);
 	if (ctx) {
-		index = root->log_transid % 2;
+		int index = root->log_transid % 2;
 		list_add_tail(&ctx->list, &root->log_ctxs[index]);
 		ctx->log_transid = root->log_transid;
 	}
+
 out:
 	mutex_unlock(&root->log_mutex);
 	return ret;
@@ -731,12 +722,66 @@ static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
 						&ordered_sums, 0);
 			if (ret)
 				goto out;
+			/*
+			 * Now delete all existing cums in the csum root that
+			 * cover our range. We do this because we can have an
+			 * extent that is completely referenced by one file
+			 * extent item and partially referenced by another
+			 * file extent item (like after using the clone or
+			 * extent_same ioctls). In this case if we end up doing
+			 * the replay of the one that partially references the
+			 * extent first, and we do not do the csum deletion
+			 * below, we can get 2 csum items in the csum tree that
+			 * overlap each other. For example, imagine our log has
+			 * the two following file extent items:
+			 *
+			 * key (257 EXTENT_DATA 409600)
+			 *     extent data disk byte 12845056 nr 102400
+			 *     extent data offset 20480 nr 20480 ram 102400
+			 *
+			 * key (257 EXTENT_DATA 819200)
+			 *     extent data disk byte 12845056 nr 102400
+			 *     extent data offset 0 nr 102400 ram 102400
+			 *
+			 * Where the second one fully references the 100K extent
+			 * that starts at disk byte 12845056, and the log tree
+			 * has a single csum item that covers the entire range
+			 * of the extent:
+			 *
+			 * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
+			 *
+			 * After the first file extent item is replayed, the
+			 * csum tree gets the following csum item:
+			 *
+			 * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
+			 *
+			 * Which covers the 20K sub-range starting at offset 20K
+			 * of our extent. Now when we replay the second file
+			 * extent item, if we do not delete existing csum items
+			 * that cover any of its blocks, we end up getting two
+			 * csum items in our csum tree that overlap each other:
+			 *
+			 * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
+			 * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
+			 *
+			 * Which is a problem, because after this anyone trying
+			 * to lookup up for the checksum of any block of our
+			 * extent starting at an offset of 40K or higher, will
+			 * end up looking at the second csum item only, which
+			 * does not contain the checksum for any block starting
+			 * at offset 40K or higher of our extent.
+			 */
 			while (!list_empty(&ordered_sums)) {
 				struct btrfs_ordered_sum *sums;
 				sums = list_entry(ordered_sums.next,
 						struct btrfs_ordered_sum,
 						list);
 				if (!ret)
+					ret = btrfs_del_csums(trans,
+						      root->fs_info->csum_root,
+						      sums->bytenr,
+						      sums->len);
+				if (!ret)
 					ret = btrfs_csum_file_blocks(trans,
 						root->fs_info->csum_root,
 						sums);
@@ -1549,9 +1594,8 @@ static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
  */
 static noinline int insert_one_name(struct btrfs_trans_handle *trans,
 				    struct btrfs_root *root,
-				    struct btrfs_path *path,
 				    u64 dirid, u64 index,
-				    char *name, int name_len, u8 type,
+				    char *name, int name_len,
 				    struct btrfs_key *location)
 {
 	struct inode *inode;
@@ -1613,6 +1657,9 @@ static bool name_in_log_ref(struct btrfs_root *log_root,
  * not exist in the FS, it is skipped.  fsyncs on directories
  * do not force down inodes inside that directory, just changes to the
  * names or unlinks in a directory.
+ *
+ * Returns < 0 on error, 0 if the name wasn't replayed (dentry points to a
+ * non-existing inode) and 1 if the name was replayed.
  */
 static noinline int replay_one_name(struct btrfs_trans_handle *trans,
 				    struct btrfs_root *root,
@@ -1631,6 +1678,7 @@ static noinline int replay_one_name(struct btrfs_trans_handle *trans,
 	int exists;
 	int ret = 0;
 	bool update_size = (key->type == BTRFS_DIR_INDEX_KEY);
+	bool name_added = false;
 
 	dir = read_one_inode(root, key->objectid);
 	if (!dir)
@@ -1708,6 +1756,8 @@ out:
 	}
 	kfree(name);
 	iput(dir);
+	if (!ret && name_added)
+		ret = 1;
 	return ret;
 
 insert:
@@ -1719,10 +1769,12 @@ insert:
 		goto out;
 	}
 	btrfs_release_path(path);
-	ret = insert_one_name(trans, root, path, key->objectid, key->offset,
-			      name, name_len, log_type, &log_key);
+	ret = insert_one_name(trans, root, key->objectid, key->offset,
+			      name, name_len, &log_key);
 	if (ret && ret != -ENOENT && ret != -EEXIST)
 		goto out;
+	if (!ret)
+		name_added = true;
 	update_size = false;
 	ret = 0;
 	goto out;
@@ -1740,12 +1792,13 @@ static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
 					struct extent_buffer *eb, int slot,
 					struct btrfs_key *key)
 {
-	int ret;
+	int ret = 0;
 	u32 item_size = btrfs_item_size_nr(eb, slot);
 	struct btrfs_dir_item *di;
 	int name_len;
 	unsigned long ptr;
 	unsigned long ptr_end;
+	struct btrfs_path *fixup_path = NULL;
 
 	ptr = btrfs_item_ptr_offset(eb, slot);
 	ptr_end = ptr + item_size;
@@ -1755,12 +1808,59 @@ static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
 			return -EIO;
 		name_len = btrfs_dir_name_len(eb, di);
 		ret = replay_one_name(trans, root, path, eb, di, key);
-		if (ret)
-			return ret;
+		if (ret < 0)
+			break;
 		ptr = (unsigned long)(di + 1);
 		ptr += name_len;
+
+		/*
+		 * If this entry refers to a non-directory (directories can not
+		 * have a link count > 1) and it was added in the transaction
+		 * that was not committed, make sure we fixup the link count of
+		 * the inode it the entry points to. Otherwise something like
+		 * the following would result in a directory pointing to an
+		 * inode with a wrong link that does not account for this dir
+		 * entry:
+		 *
+		 * mkdir testdir
+		 * touch testdir/foo
+		 * touch testdir/bar
+		 * sync
+		 *
+		 * ln testdir/bar testdir/bar_link
+		 * ln testdir/foo testdir/foo_link
+		 * xfs_io -c "fsync" testdir/bar
+		 *
+		 * <power failure>
+		 *
+		 * mount fs, log replay happens
+		 *
+		 * File foo would remain with a link count of 1 when it has two
+		 * entries pointing to it in the directory testdir. This would
+		 * make it impossible to ever delete the parent directory has
+		 * it would result in stale dentries that can never be deleted.
+		 */
+		if (ret == 1 && btrfs_dir_type(eb, di) != BTRFS_FT_DIR) {
+			struct btrfs_key di_key;
+
+			if (!fixup_path) {
+				fixup_path = btrfs_alloc_path();
+				if (!fixup_path) {
+					ret = -ENOMEM;
+					break;
+				}
+			}
+
+			btrfs_dir_item_key_to_cpu(eb, di, &di_key);
+			ret = link_to_fixup_dir(trans, root, fixup_path,
+						di_key.objectid);
+			if (ret)
+				break;
+		}
+		ret = 0;
 	}
-	return 0;
+	btrfs_free_path(fixup_path);
+	return ret;
 }
 
 /*
@@ -2535,8 +2635,7 @@ static int update_log_root(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
-static void wait_log_commit(struct btrfs_trans_handle *trans,
-			    struct btrfs_root *root, int transid)
+static void wait_log_commit(struct btrfs_root *root, int transid)
 {
 	DEFINE_WAIT(wait);
 	int index = transid % 2;
@@ -2561,8 +2660,7 @@ static void wait_log_commit(struct btrfs_trans_handle *trans,
 		 atomic_read(&root->log_commit[index]));
 }
 
-static void wait_for_writer(struct btrfs_trans_handle *trans,
-			    struct btrfs_root *root)
+static void wait_for_writer(struct btrfs_root *root)
 {
 	DEFINE_WAIT(wait);
 
@@ -2642,7 +2740,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 
 	index1 = log_transid % 2;
 	if (atomic_read(&root->log_commit[index1])) {
-		wait_log_commit(trans, root, log_transid);
+		wait_log_commit(root, log_transid);
 		mutex_unlock(&root->log_mutex);
 		return ctx->log_ret;
 	}
@@ -2651,7 +2749,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 
 	/* wait for previous tree log sync to complete */
 	if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
-		wait_log_commit(trans, root, log_transid - 1);
+		wait_log_commit(root, log_transid - 1);
 
 	while (1) {
 		int batch = atomic_read(&root->log_batch);
@@ -2662,7 +2760,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 			schedule_timeout_uninterruptible(1);
 			mutex_lock(&root->log_mutex);
 		}
-		wait_for_writer(trans, root);
+		wait_for_writer(root);
 		if (batch == atomic_read(&root->log_batch))
 			break;
 	}
@@ -2759,7 +2857,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 		ret = btrfs_wait_marked_extents(log, &log->dirty_log_pages,
 						mark);
 		btrfs_wait_logged_extents(trans, log, log_transid);
-		wait_log_commit(trans, log_root_tree,
+		wait_log_commit(log_root_tree,
 				root_log_ctx.log_transid);
 		mutex_unlock(&log_root_tree->log_mutex);
 		if (!ret)
@@ -2770,11 +2868,11 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 	atomic_set(&log_root_tree->log_commit[index2], 1);
 
 	if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
-		wait_log_commit(trans, log_root_tree,
+		wait_log_commit(log_root_tree,
 				root_log_ctx.log_transid - 1);
 	}
 
-	wait_for_writer(trans, log_root_tree);
+	wait_for_writer(log_root_tree);
 
 	/*
 	 * now that we've moved on to the tree of log tree roots,
@@ -4904,6 +5002,94 @@ next_dir_inode:
 	return ret;
 }
 
+static int btrfs_log_all_parents(struct btrfs_trans_handle *trans,
+				 struct inode *inode,
+				 struct btrfs_log_ctx *ctx)
+{
+	int ret;
+	struct btrfs_path *path;
+	struct btrfs_key key;
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+	const u64 ino = btrfs_ino(inode);
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+	path->skip_locking = 1;
+	path->search_commit_root = 1;
+
+	key.objectid = ino;
+	key.type = BTRFS_INODE_REF_KEY;
+	key.offset = 0;
+	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+	if (ret < 0)
+		goto out;
+
+	while (true) {
+		struct extent_buffer *leaf = path->nodes[0];
+		int slot = path->slots[0];
+		u32 cur_offset = 0;
+		u32 item_size;
+		unsigned long ptr;
+
+		if (slot >= btrfs_header_nritems(leaf)) {
+			ret = btrfs_next_leaf(root, path);
+			if (ret < 0)
+				goto out;
+			else if (ret > 0)
+				break;
+			continue;
+		}
+
+		btrfs_item_key_to_cpu(leaf, &key, slot);
+		/* BTRFS_INODE_EXTREF_KEY is BTRFS_INODE_REF_KEY + 1 */
+		if (key.objectid != ino || key.type > BTRFS_INODE_EXTREF_KEY)
+			break;
+
+		item_size = btrfs_item_size_nr(leaf, slot);
+		ptr = btrfs_item_ptr_offset(leaf, slot);
+		while (cur_offset < item_size) {
+			struct btrfs_key inode_key;
+			struct inode *dir_inode;
+
+			inode_key.type = BTRFS_INODE_ITEM_KEY;
+			inode_key.offset = 0;
+
+			if (key.type == BTRFS_INODE_EXTREF_KEY) {
+				struct btrfs_inode_extref *extref;
+
+				extref = (struct btrfs_inode_extref *)
+					(ptr + cur_offset);
+				inode_key.objectid = btrfs_inode_extref_parent(
+					leaf, extref);
+				cur_offset += sizeof(*extref);
+				cur_offset += btrfs_inode_extref_name_len(leaf,
+					extref);
+			} else {
+				inode_key.objectid = key.offset;
+				cur_offset = item_size;
+			}
+
+			dir_inode = btrfs_iget(root->fs_info->sb, &inode_key,
+					       root, NULL);
+			/* If parent inode was deleted, skip it. */
+			if (IS_ERR(dir_inode))
+				continue;
+
+			ret = btrfs_log_inode(trans, root, dir_inode,
+					      LOG_INODE_ALL, 0, LLONG_MAX, ctx);
+			iput(dir_inode);
+			if (ret)
+				goto out;
+		}
+		path->slots[0]++;
+	}
+	ret = 0;
+out:
+	btrfs_free_path(path);
+	return ret;
+}
+
 /*
  * helper function around btrfs_log_inode to make sure newly created
  * parent directories also end up in the log.  A minimal inode and backref
@@ -4923,9 +5109,6 @@ static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
 	struct dentry *old_parent = NULL;
 	int ret = 0;
 	u64 last_committed = root->fs_info->last_trans_committed;
-	const struct dentry * const first_parent = parent;
-	const bool did_unlink = (BTRFS_I(inode)->last_unlink_trans >
-				 last_committed);
 	bool log_dentries = false;
 	struct inode *orig_inode = inode;
 
@@ -4986,6 +5169,53 @@ static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
 	if (S_ISDIR(inode->i_mode) && ctx && ctx->log_new_dentries)
 		log_dentries = true;
 
+	/*
+	 * On unlink we must make sure all our current and old parent directores
+	 * inodes are fully logged. This is to prevent leaving dangling
+	 * directory index entries in directories that were our parents but are
+	 * not anymore. Not doing this results in old parent directory being
+	 * impossible to delete after log replay (rmdir will always fail with
+	 * error -ENOTEMPTY).
+	 *
+	 * Example 1:
+	 *
+	 * mkdir testdir
+	 * touch testdir/foo
+	 * ln testdir/foo testdir/bar
+	 * sync
+	 * unlink testdir/bar
+	 * xfs_io -c fsync testdir/foo
+	 * <power failure>
+	 * mount fs, triggers log replay
+	 *
+	 * If we don't log the parent directory (testdir), after log replay the
+	 * directory still has an entry pointing to the file inode using the bar
+	 * name, but a matching BTRFS_INODE_[REF|EXTREF]_KEY does not exist and
+	 * the file inode has a link count of 1.
+	 *
+	 * Example 2:
+	 *
+	 * mkdir testdir
+	 * touch foo
+	 * ln foo testdir/foo2
+	 * ln foo testdir/foo3
+	 * sync
+	 * unlink testdir/foo3
+	 * xfs_io -c fsync foo
+	 * <power failure>
+	 * mount fs, triggers log replay
+	 *
+	 * Similar as the first example, after log replay the parent directory
+	 * testdir still has an entry pointing to the inode file with name foo3
+	 * but the file inode does not have a matching BTRFS_INODE_REF_KEY item
+	 * and has a link count of 2.
+	 */
+	if (BTRFS_I(inode)->last_unlink_trans > last_committed) {
+		ret = btrfs_log_all_parents(trans, orig_inode, ctx);
+		if (ret)
+			goto end_trans;
+	}
+
 	while (1) {
 		if (!parent || d_really_is_negative(parent) || sb != d_inode(parent)->i_sb)
 			break;
@@ -4994,23 +5224,9 @@ static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
 		if (root != BTRFS_I(inode)->root)
 			break;
 
-		/*
-		 * On unlink we must make sure our immediate parent directory
-		 * inode is fully logged. This is to prevent leaving dangling
-		 * directory index entries and a wrong directory inode's i_size.
-		 * Not doing so can result in a directory being impossible to
-		 * delete after log replay (rmdir will always fail with error
-		 * -ENOTEMPTY).
-		 */
-		if (did_unlink && parent == first_parent)
-			inode_only = LOG_INODE_ALL;
-		else
-			inode_only = LOG_INODE_EXISTS;
-
-		if (BTRFS_I(inode)->generation >
-		    root->fs_info->last_trans_committed ||
-		    inode_only == LOG_INODE_ALL) {
-			ret = btrfs_log_inode(trans, root, inode, inode_only,
+		if (BTRFS_I(inode)->generation > last_committed) {
+			ret = btrfs_log_inode(trans, root, inode,
+					      LOG_INODE_EXISTS,
 					      0, LLONG_MAX, ctx);
 			if (ret)
 				goto end_trans;