From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C283FC169C4 for ; Mon, 11 Feb 2019 17:32:05 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3CB042229E for ; Mon, 11 Feb 2019 17:32:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ldAdxHPb"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="HHC+TaMM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3CB042229E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=XbOoYgJ7vpRWCVpOAFVisKJMg+uXVRemB0U6bNS83Rk=; b=ldAdxHPbiNvc+3 ou2N6fcre9pGXqCcX3UogrQjqIjIrdBB13LCADwnMsTT+mEgA1YrdJ5dwlaHNza9Bfs9+o66Hg8oL ZFTE/QcwfpDkgbZbOZizZ6mGpL5d5AFbAl/3P6ePgJUdV6yMENmkQFf9K5s6ey7G5+DZmAN/vi8XO CZMdB3r1NYE6Ch+6n2t73hKHrmLDLLKi4kTCCIEOrehoO8vQSF886xaWg2rcHSRlM7WJHD1CJo2ot Cc4f5YmpnRb2ikH4CdAOobS80lXddaOnxbAOLObe3rwm9Fq52yxVfIuTo37hbeJukMIJWuKNlsR9M TUgJYBdVJKsbSevN+VPA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gtFQy-0002JC-VP; Mon, 11 Feb 2019 17:31:56 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gtFOn-0007Iz-N4 for linux-mtd@lists.infradead.org; Mon, 11 Feb 2019 17:29:52 +0000 Received: from sol.localdomain (c-107-3-167-184.hsd1.ca.comcast.net [107.3.167.184]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1A352222A9; Mon, 11 Feb 2019 17:29:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549906181; bh=LHU0VKAUPXgaadVEq89d1supnSav2nCovQtUB0yGf0M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HHC+TaMMTJM3NpzleY+Gsh4zsYqdjXl27kj8EKGOxvdOQMUV76TXes1bBxZgZVLUc btxFfSTT/164wINdM4xan+haMIICRG1pQZ0tdBp1uEF5+go7g4s7oWC4rG4zRwFgEA kMuj9c9HL7pLK4CsqZRWGYgB90wmkpsHcUOPIcA4= From: Eric Biggers To: linux-fscrypt@vger.kernel.org Subject: [RFC PATCH v2 10/20] fs/dcache.c: add shrink_dcache_inode() Date: Mon, 11 Feb 2019 09:27:28 -0800 Message-Id: <20190211172738.4633-11-ebiggers@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190211172738.4633-1-ebiggers@kernel.org> References: <20190211172738.4633-1-ebiggers@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190211_092942_113876_02D2B526 X-CRM114-Status: GOOD ( 12.54 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Satya Tangirala , linux-api@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, keyrings@vger.kernel.org, linux-mtd@lists.infradead.org, linux-crypto@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, Paul Crowley Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org From: Eric Biggers When a filesystem encryption key is removed, we need all files which had been "unlocked" (had ->i_crypt_info set up) with it to appear "locked" again. This is most easily done by evicting the inodes. This can currently be done using 'echo 2 > /proc/sys/vm/drop_caches'; however, that is overkill and not usable by non-root users. To evict just the needed inodes we also need the ability to evict those inodes' dentries, since an inode is pinned by its dentries. Therefore, add a function shrink_dcache_inode() which iterates through an inode's dentries and evicts any unused ones as well as any unused descendants (since there may be negative dentries pinning the inode's dentries). Signed-off-by: Eric Biggers --- fs/dcache.c | 32 ++++++++++++++++++++++++++++++++ include/linux/dcache.h | 1 + 2 files changed, 33 insertions(+) diff --git a/fs/dcache.c b/fs/dcache.c index 2593153471cf..6a7db8797b2d 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1484,6 +1484,38 @@ void shrink_dcache_parent(struct dentry *parent) } EXPORT_SYMBOL(shrink_dcache_parent); +/** + * shrink_dcache_inode - prune dcache for inode + * @inode: inode to prune + * + * Evict all unused aliases of the specified inode from the dcache. This is + * intended to be used when trying to evict a specific inode, since inodes are + * pinned by their dentries. We also have to descend to ->d_subdirs for each + * alias, since aliases may be pinned by negative child dentries. + */ +void shrink_dcache_inode(struct inode *inode) +{ + for (;;) { + struct select_data data; + struct dentry *dentry; + + INIT_LIST_HEAD(&data.dispose); + data.start = NULL; + data.found = 0; + + spin_lock(&inode->i_lock); + hlist_for_each_entry(dentry, &inode->i_dentry, d_u.d_alias) + d_walk(dentry, &data, select_collect); + spin_unlock(&inode->i_lock); + + if (!data.found) + break; + + shrink_dentry_list(&data.dispose); + cond_resched(); + } +} + static enum d_walk_ret umount_check(void *_data, struct dentry *dentry) { /* it has busy descendents; complain about those instead */ diff --git a/include/linux/dcache.h b/include/linux/dcache.h index ef4b70f64f33..c02dab98bc97 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -245,6 +245,7 @@ extern struct dentry * d_obtain_alias(struct inode *); extern struct dentry * d_obtain_root(struct inode *); extern void shrink_dcache_sb(struct super_block *); extern void shrink_dcache_parent(struct dentry *); +extern void shrink_dcache_inode(struct inode *); extern void shrink_dcache_for_umount(struct super_block *); extern void d_invalidate(struct dentry *); -- 2.20.1 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/