[PATCH 1/8] vfs - change d_manage() to take a struct path

Ian Kent
2016-10-11T05:33:59Z

For the autofs module to be able to reliably check if a dentry is a
mountpoint in a multiple namespace environment the ->d_manage() dentry
operation will need to take a path argument instead of a dentry.

Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Omar Sandoval <osandov@osandov.com>
---
Documentation/filesystems/Locking | 2 +-
Documentation/filesystems/vfs.txt | 2 +-
fs/autofs4/root.c | 5 +++--
fs/namei.c | 13 ++++++-------
include/linux/dcache.h | 2 +-
5 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index fe15682..1949ac4 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -20,7 +20,7 @@ prototypes:
void (*d_iput)(struct dentry *, struct inode *);
char *(*d_dname)((struct dentry *dentry, char *buffer, int buflen);
struct vfsmount *(*d_automount)(struct path *path);
- int (*d_manage)(struct dentry *, bool);
+ int (*d_manage)(struct path *, bool);
struct dentry *(*d_real)(struct dentry *, const struct inode *,
unsigned int);

diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index bc3b8e0..db70d71 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -934,7 +934,7 @@ struct dentry_operations {
void (*d_iput)(struct dentry *, struct inode *);
char *(*d_dname)(struct dentry *, char *, int);
struct vfsmount *(*d_automount)(struct path *);
- int (*d_manage)(struct dentry *, bool);
+ int (*d_manage)(struct path *, bool);
struct dentry *(*d_real)(struct dentry *, const struct inode *,
unsigned int);
};
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index a11f731..5cbd4e1 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -32,7 +32,7 @@ static int autofs4_dir_open(struct inode *inode, struct file *file);
static struct dentry *autofs4_lookup(struct inode *,
struct dentry *, unsigned int);
static struct vfsmount *autofs4_d_automount(struct path *);
-static int autofs4_d_manage(struct dentry *, bool);
+static int autofs4_d_manage(struct path *, bool);
static void autofs4_dentry_release(struct dentry *);

const struct file_operations autofs4_root_operations = {
@@ -421,8 +421,9 @@ static struct vfsmount *autofs4_d_automount(struct path *path)
return NULL;
}

-static int autofs4_d_manage(struct dentry *dentry, bool rcu_walk)
+static int autofs4_d_manage(struct path *path, bool rcu_walk)
{
+ struct dentry *dentry = path->dentry;
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
int status;
diff --git a/fs/namei.c b/fs/namei.c
index a7f601c..704766a 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1200,7 +1200,7 @@ static int follow_managed(struct path *path, struct nameidata *nd)
if (managed & DCACHE_MANAGE_TRANSIT) {
BUG_ON(!path->dentry->d_op);
BUG_ON(!path->dentry->d_op->d_manage);
- ret = path->dentry->d_op->d_manage(path->dentry, false);
+ ret = path->dentry->d_op->d_manage(path, false);
if (ret < 0)
break;
}
@@ -1263,10 +1263,10 @@ int follow_down_one(struct path *path)
}
EXPORT_SYMBOL(follow_down_one);

-static inline int managed_dentry_rcu(struct dentry *dentry)
+static inline int managed_dentry_rcu(struct path *path)
{
- return (dentry->d_flags & DCACHE_MANAGE_TRANSIT) ?
- dentry->d_op->d_manage(dentry, true) : 0;
+ return (path->dentry->d_flags & DCACHE_MANAGE_TRANSIT) ?
+ path->dentry->d_op->d_manage(path, true) : 0;
}

/*
@@ -1282,7 +1282,7 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,
* Don't forget we might have a non-mountpoint managed dentry
* that wants to block transit.
*/
- switch (managed_dentry_rcu(path->dentry)) {
+ switch (managed_dentry_rcu(path)) {
case -ECHILD:
default:
return false;
@@ -1392,8 +1392,7 @@ int follow_down(struct path *path)
if (managed & DCACHE_MANAGE_TRANSIT) {
BUG_ON(!path->dentry->d_op);
BUG_ON(!path->dentry->d_op->d_manage);
- ret = path->dentry->d_op->d_manage(
- path->dentry, false);
+ ret = path->dentry->d_op->d_manage(path, false);
if (ret < 0)
return ret == -EISDIR ? 0 : ret;
}
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 5beed7b..798bc04 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -139,7 +139,7 @@ struct dentry_operations {
void (*d_iput)(struct dentry *, struct inode *);
char *(*d_dname)(struct dentry *, char *, int);
struct vfsmount *(*d_automount)(struct path *);
- int (*d_manage)(struct dentry *, bool);
+ int (*d_manage)(struct path *, bool);
struct dentry *(*d_real)(struct dentry *, const struct inode *,
unsigned int);
} ____cacheline_aligned;