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 895FD32ED2F for ; Wed, 7 Jan 2026 14:10:31 +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=1767795033; cv=none; b=IFnpCqEGfzbPhmqEvO0wTOr9tAwURC+A0NZoipcNb9V5A+e8Rj1oHDwD+Mq2rx6mtrk2nOYFM/xjyztJQ7MIottZZ5xRpzrQid1Dl+1aPgvLgne5illEffzbyqQ3/+VrXONfbSXfZITxh++2Ty+t/j0ieDFSKKv4yKExTBeThBU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767795033; c=relaxed/simple; bh=xQvdQclTydjppJ2Amx02WAgvdeL3iJ8P03EkvjNB9lk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: Mime-Version; b=MKTICXYkS6I41Ld02rS2QPdssbdk21IH+825Z5kVv49Ma7Mf3N+IzFAUgauGTgRHrZedG8L/cSsJpe5rsoa10cS3m8ekD3xwIabXQu+E5ppo8Tf2qzv20BA+NqbyRT0iUv9vioynf2HYgWpciqiLrmZHwYEDU2vsy5TWNvoBA+E= 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=4LAI0v78; 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="4LAI0v78" Received: from beren (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 741A32F186F; Wed, 7 Jan 2026 14:10:18 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=harmstone.com; s=mail; t=1767795018; bh=SrLk0LNiU+Qn3YglEzZ8Mu8nmOntxo8++rhmVq3yri8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=4LAI0v78SbaLP+hiZszEp+qQkJCW6BhOHtdXxO17wDID0mL45NmaXzKfAGsUZAS94 SPwGyv/b0gaQAOivsDtT/E3R7Bp589zJj62FsWLv8w3sBhg+VEGb7C7LidAiZUCTlB bOEladlypPFn1UUI4XDLq61aG4CXq7arhj6+lsyY= From: Mark Harmstone To: linux-btrfs@vger.kernel.org Cc: Mark Harmstone , Boris Burkov Subject: [PATCH v8 09/17] btrfs: redirect I/O for remapped block groups Date: Wed, 7 Jan 2026 14:09:09 +0000 Message-ID: <20260107141015.25819-10-mark@harmstone.com> In-Reply-To: <20260107141015.25819-1-mark@harmstone.com> References: <20260107141015.25819-1-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 Reviewed-by: Boris Burkov --- 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 310b7d817a27..525f45c668f6 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -3859,6 +3859,60 @@ 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_item *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_item); + + *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 d6060e0e2144..557ce56df800 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6584,6 +6584,25 @@ 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; -- 2.51.2