Commit fb5f51c7 authored by Ian Kent's avatar Ian Kent Committed by Al Viro
Browse files

vfs: change d_manage() to take a struct path 

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.

Link: http://lkml.kernel.org/r/20161011053352.27645.83962.stgit@pluto.themaw.net


Signed-off-by: default avatarIan 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>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent e5517c2a

Documentation/filesystems/Locking

+1 −1
Original line number Diff line number Diff line
@@ -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)(const struct path *, bool);

	struct dentry *(*d_real)(struct dentry *, const struct inode *,

				 unsigned int);

Documentation/filesystems/vfs.txt

+1 −1
Original line number Diff line number Diff line
@@ -948,7 +948,7 @@ 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)(const struct path *, bool);

	struct dentry *(*d_real)(struct dentry *, const struct inode *,

				 unsigned int);

};

fs/autofs4/root.c

+3 −2
Original line number Diff line number Diff line
@@ -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(const struct path *, bool);

static void autofs4_dentry_release(struct dentry *);



const struct file_operations autofs4_root_operations = {
@@ -421,8 +421,9 @@ done: 
	return NULL;

}



static int autofs4_d_manage(struct dentry *dentry, bool rcu_walk)

static int autofs4_d_manage(const 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;

fs/namei.c

+6 −7
Original line number Diff line number Diff line
@@ -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(const 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;

		}

include/linux/dcache.h

+1 −1
Original line number Diff line number Diff line
@@ -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)(const struct path *, bool);

	struct dentry *(*d_real)(struct dentry *, const struct inode *,

				 unsigned int);

} ____cacheline_aligned;

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