From patchwork Mon Apr 15 15:20:54 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 13630215 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1714478685 for ; Mon, 15 Apr 2024 15:21:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713194465; cv=none; b=i6PQs2/YEbgKMFpBtbNXA8PmPINl9eIK3/MM9/yHRB8XMwrbF0gh0hUaUYbwrMwEOmil5H/eEnFIfXA76pi1PiAaFdRoDL9VY2BL57rt057hj4hniBWEK867xX/ytEF6iBYX1G+ZIB2NnKAPblLPWUsFwXkxGgPBuHqKzk1tKas= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713194465; c=relaxed/simple; bh=U591gILez3TCPIxsg2AZfCAyLmatKMd0D5f4AlEzUAo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MonnEIxex5cQkuxH7cuJ1ONh50mFOqD7Tsf9IXyNEl2iBu9JB82StZIUCeTAE0jIx6KNeacwbzx1d9mLcLrI2NfI3QKuLCFXRgPLKy8B26FKfcZM45Bs7w+/QzQQLCuVneEPGOV+CcUDh03wf1bhuGiAOWigMjGvzu6a/omY56E= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tnesVMj3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="tnesVMj3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A0A8CC2BD10; Mon, 15 Apr 2024 15:21:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713194465; bh=U591gILez3TCPIxsg2AZfCAyLmatKMd0D5f4AlEzUAo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tnesVMj3h0+6+QlFogXGm3pQbaxsvGNT7TC89L75HvD36bYVy32OBCezVwERvPvcB Jy0gPRKAL1KIOR6mzXeeIwdDnIWKogDWtramNz4DW3E7geV0nfaZT0YAe8t7NLNleb ohb53LfsQ0qmRw7u8CdeOkkYZhZIaZtOu6zX59uVy/CmEI7QoqLHuegsSl0bxjELsN yEAcBpkvD3O3KWDtc7GBGR1RqA4/BlJLx4PV9TKNDzP2xZWbDQncKOAUzUcWU4D+7K w47zabvHdZbF42rD2M5ObdD4B/5h5evHJtH1XxcC8uGR1LppKu1Af3jTdBReQ46AXn 5owG47Foj/odA== From: cel@kernel.org To: Christian Brauner Cc: , Chuck Lever Subject: [PATCH v2 1/3] libfs: Fix simple_offset_rename_exchange() Date: Mon, 15 Apr 2024 11:20:54 -0400 Message-ID: <20240415152057.4605-2-cel@kernel.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240415152057.4605-1-cel@kernel.org> References: <20240415152057.4605-1-cel@kernel.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Chuck Lever User space expects the replacement (old) directory entry to have the same directory offset after the rename. Suggested-by: Christian Brauner Fixes: a2e459555c5f ("shmem: stable directory offsets") Signed-off-by: Chuck Lever --- fs/libfs.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/fs/libfs.c b/fs/libfs.c index 3a6f2cb364f8..ab61fae92cde 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -295,6 +295,18 @@ int simple_offset_add(struct offset_ctx *octx, struct dentry *dentry) return 0; } +static int simple_offset_replace(struct offset_ctx *octx, struct dentry *dentry, + long offset) +{ + int ret; + + ret = mtree_store(&octx->mt, offset, dentry, GFP_KERNEL); + if (ret) + return ret; + offset_set(dentry, offset); + return 0; +} + /** * simple_offset_remove - Remove an entry to a directory's offset map * @octx: directory offset ctx to be updated @@ -352,6 +364,9 @@ int simple_offset_empty(struct dentry *dentry) * @new_dir: destination parent * @new_dentry: destination dentry * + * This API preserves the directory offset values. Caller provides + * appropriate serialization. + * * Returns zero on success. Otherwise a negative errno is returned and the * rename is rolled back. */ @@ -369,11 +384,11 @@ int simple_offset_rename_exchange(struct inode *old_dir, simple_offset_remove(old_ctx, old_dentry); simple_offset_remove(new_ctx, new_dentry); - ret = simple_offset_add(new_ctx, old_dentry); + ret = simple_offset_replace(new_ctx, old_dentry, new_index); if (ret) goto out_restore; - ret = simple_offset_add(old_ctx, new_dentry); + ret = simple_offset_replace(old_ctx, new_dentry, old_index); if (ret) { simple_offset_remove(new_ctx, old_dentry); goto out_restore; @@ -388,10 +403,8 @@ int simple_offset_rename_exchange(struct inode *old_dir, return 0; out_restore: - offset_set(old_dentry, old_index); - mtree_store(&old_ctx->mt, old_index, old_dentry, GFP_KERNEL); - offset_set(new_dentry, new_index); - mtree_store(&new_ctx->mt, new_index, new_dentry, GFP_KERNEL); + (void)simple_offset_replace(old_ctx, old_dentry, old_index); + (void)simple_offset_replace(new_ctx, new_dentry, new_index); return ret; }