From mboxrd@z Thu Jan 1 00:00:00 1970 From: Amir Goldstein Subject: [PATCH v4 08/25] ovl: store path type in dentry Date: Wed, 21 Jun 2017 15:28:39 +0300 Message-ID: <1498048136-28218-9-git-send-email-amir73il@gmail.com> References: <1498048136-28218-1-git-send-email-amir73il@gmail.com> Return-path: Received: from mail-wr0-f193.google.com ([209.85.128.193]:36554 "EHLO mail-wr0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751839AbdFUM2z (ORCPT ); Wed, 21 Jun 2017 08:28:55 -0400 Received: by mail-wr0-f193.google.com with SMTP id 77so26084999wrb.3 for ; Wed, 21 Jun 2017 05:28:54 -0700 (PDT) In-Reply-To: <1498048136-28218-1-git-send-email-amir73il@gmail.com> Sender: linux-unionfs-owner@vger.kernel.org List-Id: linux-unionfs@vger.kernel.org To: Miklos Szeredi Cc: linux-unionfs@vger.kernel.org We would like to be able to set type flags during lookup (i.e. INDEX) instead of deducing them from other state information. Store the type value in ovl_entry and update the UPPER/MERGE/ORIGIN flags when needed, so ovl_path_type() just returns the stored value. Signed-off-by: Amir Goldstein --- fs/overlayfs/namei.c | 1 + fs/overlayfs/overlayfs.h | 1 + fs/overlayfs/ovl_entry.h | 3 +++ fs/overlayfs/super.c | 1 + fs/overlayfs/util.c | 20 +++++++++++++++++--- 5 files changed, 23 insertions(+), 3 deletions(-) diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index 400ad20ceb15..6e827a2b1cf0 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -548,6 +548,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, kfree(stack); kfree(d.redirect); dentry->d_fsdata = oe; + ovl_update_type(dentry, d.is_dir); d_add(dentry, inode); return NULL; diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 612b6e45c64b..09852c879046 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -199,6 +199,7 @@ struct ovl_entry *ovl_alloc_entry(unsigned int numlower); bool ovl_dentry_remote(struct dentry *dentry); bool ovl_dentry_weird(struct dentry *dentry); enum ovl_path_type ovl_path_type(struct dentry *dentry); +void ovl_update_type(struct dentry *dentry, bool is_dir); void ovl_path_upper(struct dentry *dentry, struct path *path); void ovl_path_lower(struct dentry *dentry, struct path *path); enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index ddd4b0a874a9..e94fa2638faf 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -40,6 +40,8 @@ struct ovl_fs { struct super_block *same_sb; }; +enum ovl_path_type; + /* private information held for every overlayfs dentry */ struct ovl_entry { struct dentry *__upperdentry; @@ -54,6 +56,7 @@ struct ovl_entry { }; struct rcu_head rcu; }; + enum ovl_path_type __type; unsigned numlower; struct path lowerstack[]; }; diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index a9de7d1893e2..c72d79749652 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -1105,6 +1105,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) kfree(stack); root_dentry->d_fsdata = oe; + ovl_update_type(root_dentry, true); realinode = d_inode(ovl_dentry_real(root_dentry)); ovl_inode_init(d_inode(root_dentry), realinode, !!upperpath.dentry); diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index 8e2f308056f1..8e743c76aa03 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -91,24 +91,37 @@ bool ovl_dentry_weird(struct dentry *dentry) enum ovl_path_type ovl_path_type(struct dentry *dentry) { struct ovl_entry *oe = dentry->d_fsdata; + + return READ_ONCE(oe->__type); +} + +void ovl_update_type(struct dentry *dentry, bool is_dir) +{ + struct ovl_entry *oe = dentry->d_fsdata; enum ovl_path_type type = 0; + spin_lock(&dentry->d_lock); if (oe->__upperdentry) { type = __OVL_PATH_UPPER; - /* * Non-dir dentry can hold lower dentry of its copy up origin. */ if (oe->numlower) { type |= __OVL_PATH_ORIGIN; - if (d_is_dir(dentry)) + if (is_dir) type |= __OVL_PATH_MERGE; } } else { if (oe->numlower > 1) type |= __OVL_PATH_MERGE; } - return type; + + /* + * The UPPER/MERGE/ORIGIN flags can never be cleared during the + * lifetime of a dentry, so don't bother masking them out first. + */ + oe->__type |= type; + spin_unlock(&dentry->d_lock); } void ovl_path_upper(struct dentry *dentry, struct path *path) @@ -243,6 +256,7 @@ void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry) */ smp_wmb(); oe->__upperdentry = upperdentry; + ovl_update_type(dentry, d_is_dir(dentry)); } void ovl_inode_init(struct inode *inode, struct inode *realinode, bool is_upper) -- 2.7.4