From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.burntcomma.com (mail2.burntcomma.com [217.169.27.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 57BAA347FC9 for ; Fri, 24 Oct 2025 18:12:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.169.27.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761329565; cv=none; b=fX3e6tVRaNuEa0NJTmG/djzbmmidxlp1Go5XnCrb8vj0159lOUimQT3SXYB+ZnS79Ip8HiDilALp4E8x1Ls/hVJdPN130RPI5M2Ti05clUdOWZ7XxMuIdjSDccFTvcJC016BUbajkw/zr0NHkuoQ2+ZtSocCiak3Uc6hW/lrDQY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761329565; c=relaxed/simple; bh=bHjIUPVRteKYWzlMS0V5eH8InjMJX1H3E9jRE1it3aU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: Mime-Version; b=REb+1hlV6PFCnK1w425S83xDlfHyN3hMaNHskrft6cINPA9sHY2/adwtI5oipYOWAsH+rnMYgA365Rk4aXM/ceasp6OHhNNlzzK+IvsP86gSQwtWQpdOZGhrNy8eKq1QU+o/CemW61eN2zmuwzGBTAs50J0PaATKxSqvHJs8jV0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=harmstone.com; spf=pass smtp.mailfrom=harmstone.com; dkim=pass (1024-bit key) header.d=harmstone.com header.i=@harmstone.com header.b=d7SwtqX+; arc=none smtp.client-ip=217.169.27.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=harmstone.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=harmstone.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=harmstone.com header.i=@harmstone.com header.b="d7SwtqX+" Received: from localhost.localdomain (beren.burntcomma.com [IPv6:2a02:8012:8cf0:0:ce28:aaff:fe0d:6db2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (Client did not present a certificate) by mail.burntcomma.com (Postfix) with ESMTPSA id B60672CFE4D; Fri, 24 Oct 2025 19:12:30 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=harmstone.com; s=mail; t=1761329550; bh=Imi+Yf5MWEiF05UpsW5b3tO5BwIxxNVXjCMSGrqRPdQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=d7SwtqX+l4FEqut2xJ6vhH9iJIj5BcpGks8i48Sv7smsf8sC6wu0hQlW93zyi1v/X 7cLUMUfpfLU/Ey6CObEsqILvIWHbNbto3xOrgttCxds2NWg3ULk/Uib84zJmkpIIuv Vr01J8700+zHb6ykuoc4BwALmT1edgE/I+RzSKqQ= From: Mark Harmstone To: linux-btrfs@vger.kernel.org Cc: Mark Harmstone Subject: [PATCH v4 08/16] btrfs: redirect I/O for remapped block groups Date: Fri, 24 Oct 2025 19:12:09 +0100 Message-ID: <20251024181227.32228-9-mark@harmstone.com> In-Reply-To: <20251024181227.32228-1-mark@harmstone.com> References: <20251024181227.32228-1-mark@harmstone.com> Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Change btrfs_map_block() so that if the block group has the REMAPPED flag set, we call btrfs_translate_remap() to obtain a new address. btrfs_translate_remap() searches the remap tree for a range corresponding to the logical address passed to btrfs_map_block(). If it is within an identity remap, this part of the block group hasn't yet been relocated, and so we use the existing address. If it is within an actual remap, we subtract the start of the remap range and add the address of its destination, contained in the item's payload. Signed-off-by: Mark Harmstone --- fs/btrfs/relocation.c | 54 +++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/relocation.h | 2 ++ fs/btrfs/volumes.c | 19 +++++++++++++++ 3 files changed, 75 insertions(+) diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 96539e8b7b4b..a8abe24de8d7 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -3870,6 +3870,60 @@ static const char *stage_to_string(enum reloc_stage stage) return "unknown"; } +int btrfs_translate_remap(struct btrfs_fs_info *fs_info, u64 *logical, + u64 *length) +{ + int ret; + struct btrfs_key key, found_key; + struct extent_buffer *leaf; + struct btrfs_remap *remap; + BTRFS_PATH_AUTO_FREE(path); + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = *logical; + key.type = (u8)-1; + key.offset = (u64)-1; + + ret = btrfs_search_slot(NULL, fs_info->remap_root, &key, path, + 0, 0); + if (ret < 0) + return ret; + + leaf = path->nodes[0]; + + if (path->slots[0] == 0) + return -ENOENT; + + path->slots[0]--; + + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + if (found_key.type != BTRFS_REMAP_KEY && + found_key.type != BTRFS_IDENTITY_REMAP_KEY) { + return -ENOENT; + } + + if (found_key.objectid > *logical || + found_key.objectid + found_key.offset <= *logical) { + return -ENOENT; + } + + if (*logical + *length > found_key.objectid + found_key.offset) + *length = found_key.objectid + found_key.offset - *logical; + + if (found_key.type == BTRFS_IDENTITY_REMAP_KEY) + return 0; + + remap = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_remap); + + *logical += btrfs_remap_address(leaf, remap) - found_key.objectid; + + return 0; +} + /* * function to relocate all extents in a block group. */ diff --git a/fs/btrfs/relocation.h b/fs/btrfs/relocation.h index 5c36b3f84b57..b2ba83966650 100644 --- a/fs/btrfs/relocation.h +++ b/fs/btrfs/relocation.h @@ -31,5 +31,7 @@ int btrfs_should_cancel_balance(const struct btrfs_fs_info *fs_info); struct btrfs_root *find_reloc_root(struct btrfs_fs_info *fs_info, u64 bytenr); bool btrfs_should_ignore_reloc_root(const struct btrfs_root *root); u64 btrfs_get_reloc_bg_bytenr(const struct btrfs_fs_info *fs_info); +int btrfs_translate_remap(struct btrfs_fs_info *fs_info, u64 *logical, + u64 *length); #endif diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 7b2bec28dbd7..d117f74e08c1 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6598,6 +6598,25 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op, if (IS_ERR(map)) return PTR_ERR(map); + if (map->type & BTRFS_BLOCK_GROUP_REMAPPED) { + u64 new_logical = logical; + + ret = btrfs_translate_remap(fs_info, &new_logical, length); + if (ret) + return ret; + + if (new_logical != logical) { + btrfs_free_chunk_map(map); + + map = btrfs_get_chunk_map(fs_info, new_logical, + *length); + if (IS_ERR(map)) + return PTR_ERR(map); + + logical = new_logical; + } + } + num_copies = btrfs_chunk_map_num_copies(map); if (io_geom.mirror_num > num_copies) return -EINVAL; -- 2.49.1