linux-kernel - [PATCH 2/3] ncpfs: don't use ->d

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon,  7 Nov 2016 11:51:59 +0100
From:   Miklos Szeredi <mszeredi@...hat.com>
To:     Al Viro <viro@...IV.linux.org.uk>
Cc:     Trond Myklebust <trond.myklebust@...marydata.com>,
        linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 2/3] ncpfs: don't use ->d_time

Ncpfs stores a boolean value in ->d_fsdata as well as using d_time.
Introcude ncp_dentry to store both of these and make d_fsdata point to it.

Signed-off-by: Miklos Szeredi <mszeredi@...hat.com>
---
 fs/ncpfs/dir.c           | 21 ++++++++++++++++++---
 fs/ncpfs/ncplib_kernel.h | 16 +++++++++++++---
 2 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index 6df2a3827574..ce42dbdde777 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -72,6 +72,8 @@ const struct inode_operations ncp_dir_inode_operations =
 /*
  * Dentry operations routines
  */
+static int ncp_d_init(struct dentry *);
+static void ncp_d_release(struct dentry *);
 static int ncp_lookup_validate(struct dentry *, unsigned int);
 static int ncp_hash_dentry(const struct dentry *, struct qstr *);
 static int ncp_compare_dentry(const struct dentry *,
@@ -81,6 +83,8 @@ static void ncp_d_prune(struct dentry *dentry);
 
 const struct dentry_operations ncp_dentry_operations =
 {
+	.d_init		= ncp_d_init,
+	.d_release	= ncp_d_release,
 	.d_revalidate	= ncp_lookup_validate,
 	.d_hash		= ncp_hash_dentry,
 	.d_compare	= ncp_compare_dentry,
@@ -305,6 +309,17 @@ leave_me:;
 }
 #endif	/* CONFIG_NCPFS_STRONG */
 
+static int ncp_d_init(struct dentry *dentry)
+{
+	dentry->d_fsdata = kzalloc(sizeof(struct ncp_dentry), GFP_KERNEL);
+
+	return dentry->d_fsdata ? 0 : -ENOMEM;
+}
+
+static void ncp_d_release(struct dentry *dentry)
+{
+	kfree(dentry->d_fsdata);
+}
 
 static int
 ncp_lookup_validate(struct dentry *dentry, unsigned int flags)
@@ -408,7 +423,7 @@ ncp_invalidate_dircache_entries(struct dentry *parent)
 
 	spin_lock(&parent->d_lock);
 	list_for_each_entry(dentry, &parent->d_subdirs, d_child) {
-		dentry->d_fsdata = NULL;
+		NCP_DENTRY(dentry)->cached = false;
 		ncp_age_dentry(server, dentry);
 	}
 	spin_unlock(&parent->d_lock);
@@ -568,7 +583,7 @@ static int ncp_readdir(struct file *file, struct dir_context *ctx)
 
 static void ncp_d_prune(struct dentry *dentry)
 {
-	if (!dentry->d_fsdata)	/* not referenced from page cache */
+	if (!NCP_DENTRY(dentry)->cached) /* not referenced from page cache */
 		return;
 	NCP_FINFO(d_inode(dentry->d_parent))->flags &= ~NCPI_DIR_CACHE;
 }
@@ -659,7 +674,7 @@ ncp_fill_cache(struct file *file, struct dir_context *ctx,
 	}
 	if (ctl.cache) {
 		if (d_really_is_positive(newdent)) {
-			newdent->d_fsdata = newdent;
+			NCP_DENTRY(newdent)->cached = true;
 			ctl.cache->dentry[ctl.idx] = newdent;
 			ino = d_inode(newdent)->i_ino;
 			ncp_new_dentry(newdent);
diff --git a/fs/ncpfs/ncplib_kernel.h b/fs/ncpfs/ncplib_kernel.h
index 17cfb743b5bf..76459e4f6b64 100644
--- a/fs/ncpfs/ncplib_kernel.h
+++ b/fs/ncpfs/ncplib_kernel.h
@@ -168,20 +168,30 @@ static inline int ncp_strnicmp(const struct nls_table *t,
 
 #endif /* CONFIG_NCPFS_NLS */
 
-#define NCP_GET_AGE(dentry)	(jiffies - (dentry)->d_time)
+struct ncp_dentry {
+	unsigned long time;
+	bool cached;
+};
+
+static inline struct ncp_dentry *NCP_DENTRY(struct dentry *dentry)
+{
+	return (struct ncp_dentry *) dentry->d_fsdata;
+}
+
+#define NCP_GET_AGE(dentry)	(jiffies - NCP_DENTRY(dentry)->time)
 #define NCP_MAX_AGE(server)	atomic_read(&(server)->dentry_ttl)
 #define NCP_TEST_AGE(server,dentry)	(NCP_GET_AGE(dentry) < NCP_MAX_AGE(server))
 
 static inline void
 ncp_age_dentry(struct ncp_server* server, struct dentry* dentry)
 {
-	dentry->d_time = jiffies - NCP_MAX_AGE(server);
+	NCP_DENTRY(dentry)->time = jiffies - NCP_MAX_AGE(server);
 }
 
 static inline void
 ncp_new_dentry(struct dentry* dentry)
 {
-	dentry->d_time = jiffies;
+	NCP_DENTRY(dentry)->time = jiffies;
 }
 
 struct ncp_cache_head {
-- 
2.5.5