From patchwork Wed Mar 17 04:56:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Chinner X-Patchwork-Id: 12144829 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 AEF56C4332B for ; Wed, 17 Mar 2021 04:58:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8C54364FB4 for ; Wed, 17 Mar 2021 04:58:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229846AbhCQE5r (ORCPT ); Wed, 17 Mar 2021 00:57:47 -0400 Received: from mail107.syd.optusnet.com.au ([211.29.132.53]:33625 "EHLO mail107.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229862AbhCQE5X (ORCPT ); Wed, 17 Mar 2021 00:57:23 -0400 Received: from dread.disaster.area (pa49-181-239-12.pa.nsw.optusnet.com.au [49.181.239.12]) by mail107.syd.optusnet.com.au (Postfix) with ESMTPS id 696741060 for ; Wed, 17 Mar 2021 15:57:11 +1100 (AEDT) Received: from discord.disaster.area ([192.168.253.110]) by dread.disaster.area with esmtp (Exim 4.92.3) (envelope-from ) id 1lMOF3-003R8B-0X for linux-xfs@vger.kernel.org; Wed, 17 Mar 2021 15:57:09 +1100 Received: from dave by discord.disaster.area with local (Exim 4.94) (envelope-from ) id 1lMOF2-002jZu-OP for linux-xfs@vger.kernel.org; Wed, 17 Mar 2021 15:57:08 +1100 From: Dave Chinner To: linux-xfs@vger.kernel.org Subject: [PATCH 1/8] xfs: initialise attr fork on inode create Date: Wed, 17 Mar 2021 15:56:59 +1100 Message-Id: <20210317045706.651306-2-david@fromorbit.com> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210317045706.651306-1-david@fromorbit.com> References: <20210317045706.651306-1-david@fromorbit.com> MIME-Version: 1.0 X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=YKPhNiOx c=1 sm=1 tr=0 cx=a_idp_d a=gO82wUwQTSpaJfP49aMSow==:117 a=gO82wUwQTSpaJfP49aMSow==:17 a=dESyimp9J3IA:10 a=20KFwNOVAAAA:8 a=VwQbUJbxAAAA:8 a=k0WJhPe4DV5wXDVh-LAA:9 a=AjGcO6oz07-iQ99wixmX:22 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org From: Dave Chinner When we allocate a new inode, we often need to add an attribute to the inode as part of the create. This can happen as a result of needing to add default ACLs or security labels before the inode is made visible to userspace. This is highly inefficient right now. We do the create transaction to allocate the inode, then we do an "add attr fork" transaction to modify the just created empty inode to set the inode fork offset to allow attributes to be stored, then we go and do the attribute creation. This means 3 transactions instead of 1 to allocate an inode, and this greatly increases the load on the CIL commit code, resulting in excessive contention on the CIL spin locks and performance degradation: 18.99% [kernel] [k] __pv_queued_spin_lock_slowpath 3.57% [kernel] [k] do_raw_spin_lock 2.51% [kernel] [k] __raw_callee_save___pv_queued_spin_unlock 2.48% [kernel] [k] memcpy 2.34% [kernel] [k] xfs_log_commit_cil The typical profile resulting from running fsmark on a selinux enabled filesytem is adds this overhead to the create path: - 15.30% xfs_init_security - 15.23% security_inode_init_security - 13.05% xfs_initxattrs - 12.94% xfs_attr_set - 6.75% xfs_bmap_add_attrfork - 5.51% xfs_trans_commit - 5.48% __xfs_trans_commit - 5.35% xfs_log_commit_cil - 3.86% _raw_spin_lock - do_raw_spin_lock __pv_queued_spin_lock_slowpath - 0.70% xfs_trans_alloc 0.52% xfs_trans_reserve - 5.41% xfs_attr_set_args - 5.39% xfs_attr_set_shortform.constprop.0 - 4.46% xfs_trans_commit - 4.46% __xfs_trans_commit - 4.33% xfs_log_commit_cil - 2.74% _raw_spin_lock - do_raw_spin_lock __pv_queued_spin_lock_slowpath 0.60% xfs_inode_item_format 0.90% xfs_attr_try_sf_addname - 1.99% selinux_inode_init_security - 1.02% security_sid_to_context_force - 1.00% security_sid_to_context_core - 0.92% sidtab_entry_to_string - 0.90% sidtab_sid2str_get 0.59% sidtab_sid2str_put.part.0 - 0.82% selinux_determine_inode_label - 0.77% security_transition_sid 0.70% security_compute_sid.part.0 And fsmark creation rate performance drops by ~25%. The key point to note here is that half the additional overhead comes from adding the attribute fork to the newly created inode. That's crazy, considering we can do this same thing at inode create time with a couple of lines of code and no extra overhead. So, if we know we are going to add an attribute immediately after creating the inode, let's just initialise the attribute fork inside the create transaction and chop that whole chunk of code out of the create fast path. This completely removes the performance drop caused by enabling SELinux, and the profile looks like: - 8.99% xfs_init_security - 9.00% security_inode_init_security - 6.43% xfs_initxattrs - 6.37% xfs_attr_set - 5.45% xfs_attr_set_args - 5.42% xfs_attr_set_shortform.constprop.0 - 4.51% xfs_trans_commit - 4.54% __xfs_trans_commit - 4.59% xfs_log_commit_cil - 2.67% _raw_spin_lock - 3.28% do_raw_spin_lock 3.08% __pv_queued_spin_lock_slowpath 0.66% xfs_inode_item_format - 0.90% xfs_attr_try_sf_addname - 0.60% xfs_trans_alloc - 2.35% selinux_inode_init_security - 1.25% security_sid_to_context_force - 1.21% security_sid_to_context_core - 1.19% sidtab_entry_to_string - 1.20% sidtab_sid2str_get - 0.86% sidtab_sid2str_put.part.0 - 0.62% _raw_spin_lock_irqsave - 0.77% do_raw_spin_lock __pv_queued_spin_lock_slowpath - 0.84% selinux_determine_inode_label - 0.83% security_transition_sid 0.86% security_compute_sid.part.0 Which indicates the XFS overhead of creating the selinux xattr has been halved. This doesn't fix the CIL lock contention problem, just means it's not a limiting factor for this workload. Lock contention in the security subsystems is going to be an issue soon, though... Signed-off-by: Dave Chinner Reviewed-by: Darrick J. Wong Reviewed-by: Gao Xiang --- fs/xfs/libxfs/xfs_bmap.c | 9 ++++----- fs/xfs/libxfs/xfs_inode_fork.c | 20 +++++++++++++++----- fs/xfs/libxfs/xfs_inode_fork.h | 2 ++ fs/xfs/xfs_inode.c | 24 +++++++++++++++++++++--- fs/xfs/xfs_inode.h | 6 ++++-- fs/xfs/xfs_iops.c | 34 +++++++++++++++++++++++++++++++++- fs/xfs/xfs_qm.c | 2 +- fs/xfs/xfs_symlink.c | 2 +- 8 files changed, 81 insertions(+), 18 deletions(-) diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index e0905ad171f0..5574d345d066 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -1027,7 +1027,9 @@ xfs_bmap_add_attrfork_local( return -EFSCORRUPTED; } -/* Set an inode attr fork off based on the format */ +/* + * Set an inode attr fork offset based on the format of the data fork. + */ int xfs_bmap_set_attrforkoff( struct xfs_inode *ip, @@ -1092,10 +1094,7 @@ xfs_bmap_add_attrfork( goto trans_cancel; ASSERT(ip->i_afp == NULL); - ip->i_afp = kmem_cache_zalloc(xfs_ifork_zone, - GFP_KERNEL | __GFP_NOFAIL); - - ip->i_afp->if_format = XFS_DINODE_FMT_EXTENTS; + ip->i_afp = xfs_ifork_alloc(XFS_DINODE_FMT_EXTENTS, 0); ip->i_afp->if_flags = XFS_IFEXTENTS; logflags = 0; switch (ip->i_df.if_format) { diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c index e080d7e07643..c606c1a77e5a 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.c +++ b/fs/xfs/libxfs/xfs_inode_fork.c @@ -282,6 +282,19 @@ xfs_dfork_attr_shortform_size( return be16_to_cpu(atp->hdr.totsize); } +struct xfs_ifork * +xfs_ifork_alloc( + enum xfs_dinode_fmt format, + xfs_extnum_t nextents) +{ + struct xfs_ifork *ifp; + + ifp = kmem_cache_zalloc(xfs_ifork_zone, GFP_NOFS | __GFP_NOFAIL); + ifp->if_format = format; + ifp->if_nextents = nextents; + return ifp; +} + int xfs_iformat_attr_fork( struct xfs_inode *ip, @@ -293,11 +306,8 @@ xfs_iformat_attr_fork( * Initialize the extent count early, as the per-format routines may * depend on it. */ - ip->i_afp = kmem_cache_zalloc(xfs_ifork_zone, GFP_NOFS | __GFP_NOFAIL); - ip->i_afp->if_format = dip->di_aformat; - if (unlikely(ip->i_afp->if_format == 0)) /* pre IRIX 6.2 file system */ - ip->i_afp->if_format = XFS_DINODE_FMT_EXTENTS; - ip->i_afp->if_nextents = be16_to_cpu(dip->di_anextents); + ip->i_afp = xfs_ifork_alloc(dip->di_aformat, + be16_to_cpu(dip->di_anextents)); switch (ip->i_afp->if_format) { case XFS_DINODE_FMT_LOCAL: diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h index 9e2137cd7372..a0717ab0e5c5 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.h +++ b/fs/xfs/libxfs/xfs_inode_fork.h @@ -141,6 +141,8 @@ static inline int8_t xfs_ifork_format(struct xfs_ifork *ifp) return ifp->if_format; } +struct xfs_ifork *xfs_ifork_alloc(enum xfs_dinode_fmt format, + xfs_extnum_t nextents); struct xfs_ifork *xfs_iext_state_to_fork(struct xfs_inode *ip, int state); int xfs_iformat_data_fork(struct xfs_inode *, struct xfs_dinode *); diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index f93370bd7b1e..97c5dd081ead 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -774,6 +774,7 @@ xfs_init_new_inode( xfs_nlink_t nlink, dev_t rdev, prid_t prid, + bool init_xattrs, struct xfs_inode **ipp) { struct inode *dir = pip ? VFS_I(pip) : NULL; @@ -877,6 +878,20 @@ xfs_init_new_inode( ASSERT(0); } + /* + * If we need to create attributes immediately after allocating the + * inode, initialise an empty attribute fork right now. We use the + * default fork offset for attributes here as we don't know exactly what + * size or how many attributes we might be adding. We can do this + * safely here because we know the data fork is completely empty and + * this saves us from needing to run a separate transaction to set the + * fork offset in the immediate future. + */ + if (init_xattrs) { + ip->i_d.di_forkoff = xfs_default_attroffset(ip) >> 3; + ip->i_afp = xfs_ifork_alloc(XFS_DINODE_FMT_EXTENTS, 0); + } + /* * Log the new values stuffed into the inode. */ @@ -910,6 +925,7 @@ xfs_dir_ialloc( xfs_nlink_t nlink, dev_t rdev, prid_t prid, + bool init_xattrs, struct xfs_inode **ipp) { struct xfs_buf *agibp; @@ -937,7 +953,7 @@ xfs_dir_ialloc( ASSERT(ino != NULLFSINO); return xfs_init_new_inode(mnt_userns, *tpp, dp, ino, mode, nlink, rdev, - prid, ipp); + prid, init_xattrs, ipp); } /* @@ -982,6 +998,7 @@ xfs_create( struct xfs_name *name, umode_t mode, dev_t rdev, + bool init_xattrs, xfs_inode_t **ipp) { int is_dir = S_ISDIR(mode); @@ -1053,7 +1070,7 @@ xfs_create( * pointing to itself. */ error = xfs_dir_ialloc(mnt_userns, &tp, dp, mode, is_dir ? 2 : 1, rdev, - prid, &ip); + prid, init_xattrs, &ip); if (error) goto out_trans_cancel; @@ -1173,7 +1190,8 @@ xfs_create_tmpfile( if (error) goto out_release_dquots; - error = xfs_dir_ialloc(mnt_userns, &tp, dp, mode, 0, 0, prid, &ip); + error = xfs_dir_ialloc(mnt_userns, &tp, dp, mode, 0, 0, prid, + false, &ip); if (error) goto out_trans_cancel; diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h index 88ee4c3930ae..a2cacdb76d55 100644 --- a/fs/xfs/xfs_inode.h +++ b/fs/xfs/xfs_inode.h @@ -371,7 +371,8 @@ int xfs_lookup(struct xfs_inode *dp, struct xfs_name *name, struct xfs_inode **ipp, struct xfs_name *ci_name); int xfs_create(struct user_namespace *mnt_userns, struct xfs_inode *dp, struct xfs_name *name, - umode_t mode, dev_t rdev, struct xfs_inode **ipp); + umode_t mode, dev_t rdev, bool need_xattr, + struct xfs_inode **ipp); int xfs_create_tmpfile(struct user_namespace *mnt_userns, struct xfs_inode *dp, umode_t mode, struct xfs_inode **ipp); @@ -413,7 +414,8 @@ xfs_extlen_t xfs_get_cowextsz_hint(struct xfs_inode *ip); int xfs_dir_ialloc(struct user_namespace *mnt_userns, struct xfs_trans **tpp, struct xfs_inode *dp, umode_t mode, xfs_nlink_t nlink, dev_t dev, - prid_t prid, struct xfs_inode **ipp); + prid_t prid, bool need_xattr, + struct xfs_inode **ipp); static inline int xfs_itruncate_extents( diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c index 66ebccb5a6ff..a9d466b78646 100644 --- a/fs/xfs/xfs_iops.c +++ b/fs/xfs/xfs_iops.c @@ -126,6 +126,37 @@ xfs_cleanup_inode( xfs_remove(XFS_I(dir), &teardown, XFS_I(inode)); } +/* + * Check to see if we are likely to need an extended attribute to be added to + * the inode we are about to allocate. This allows the attribute fork to be + * created during the inode allocation, reducing the number of transactions we + * need to do in this fast path. + * + * The security checks are optimistic, but not guaranteed. The two LSMs that + * require xattrs to be added here (selinux and smack) are also the only two + * LSMs that add a sb->s_security structure to the superblock. Hence if security + * is enabled and sb->s_security is set, we have a pretty good idea that we are + * going to be asked to add a security xattr immediately after allocating the + * xfs inode and instantiating the VFS inode. + */ +static inline bool +xfs_create_need_xattr( + struct inode *dir, + struct posix_acl *default_acl, + struct posix_acl *acl) +{ + if (acl) + return true; + if (default_acl) + return true; + if (!IS_ENABLED(CONFIG_SECURITY)) + return false; + if (dir->i_sb->s_security) + return true; + return false; +} + + STATIC int xfs_generic_create( struct user_namespace *mnt_userns, @@ -163,7 +194,8 @@ xfs_generic_create( if (!tmpfile) { error = xfs_create(mnt_userns, XFS_I(dir), &name, mode, rdev, - &ip); + xfs_create_need_xattr(dir, default_acl, acl), + &ip); } else { error = xfs_create_tmpfile(mnt_userns, XFS_I(dir), mode, &ip); } diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c index bfa4164990b1..6fde318b9fed 100644 --- a/fs/xfs/xfs_qm.c +++ b/fs/xfs/xfs_qm.c @@ -788,7 +788,7 @@ xfs_qm_qino_alloc( if (need_alloc) { error = xfs_dir_ialloc(&init_user_ns, &tp, NULL, S_IFREG, 1, 0, - 0, ipp); + 0, false, ipp); if (error) { xfs_trans_cancel(tp); return error; diff --git a/fs/xfs/xfs_symlink.c b/fs/xfs/xfs_symlink.c index 7f368b10ded1..db9c400f9258 100644 --- a/fs/xfs/xfs_symlink.c +++ b/fs/xfs/xfs_symlink.c @@ -224,7 +224,7 @@ xfs_symlink( * Allocate an inode for the symlink. */ error = xfs_dir_ialloc(mnt_userns, &tp, dp, S_IFLNK | (mode & ~S_IFMT), - 1, 0, prid, &ip); + 1, 0, prid, false, &ip); if (error) goto out_trans_cancel;