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Commit b1942c5f authored by Al Viro's avatar Al Viro
Browse files

nfs: store devname at disconnected NFS roots 



part 2: make sure that disconnected roots have corresponding mnt_devname
values stashed into them.

Have nfs*_get_root() stuff a copy of devname into ->d_fsdata of the
found root, provided that it is disconnected.

Have ->d_release() free it when dentry goes away.

Have the places where NFS uses ->d_fsdata for sillyrename (and that
can *never* happen to a disconnected root - dentry will be attached
to its parent) free old devname copies if they find those.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 0d5839ad

fs/nfs/dir.c

+13 −0
Original line number Diff line number Diff line
@@ -1169,11 +1169,23 @@ static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode) 
	iput(inode);

}



static void nfs_d_release(struct dentry *dentry)

{

	/* free cached devname value, if it survived that far */

	if (unlikely(dentry->d_fsdata)) {

		if (dentry->d_flags & DCACHE_NFSFS_RENAMED)

			WARN_ON(1);

		else

			kfree(dentry->d_fsdata);

	}

}



const struct dentry_operations nfs_dentry_operations = {

	.d_revalidate	= nfs_lookup_revalidate,

	.d_delete	= nfs_dentry_delete,

	.d_iput		= nfs_dentry_iput,

	.d_automount	= nfs_d_automount,

	.d_release	= nfs_d_release,

};



static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
@@ -1248,6 +1260,7 @@ const struct dentry_operations nfs4_dentry_operations = { 
	.d_delete	= nfs_dentry_delete,

	.d_iput		= nfs_dentry_iput,

	.d_automount	= nfs_d_automount,

	.d_release	= nfs_d_release,

};



/*

fs/nfs/getroot.c

+32 −4
Original line number Diff line number Diff line
@@ -82,12 +82,18 @@ struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh, 
	struct nfs_fsinfo fsinfo;

	struct dentry *ret;

	struct inode *inode;

	void *name = kstrdup(devname, GFP_KERNEL);

	int error;



	if (!name)

		return ERR_PTR(-ENOMEM);



	/* get the actual root for this mount */

	fsinfo.fattr = nfs_alloc_fattr();

	if (fsinfo.fattr == NULL)

	if (fsinfo.fattr == NULL) {

		kfree(name);

		return ERR_PTR(-ENOMEM);

	}



	error = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo);

	if (error < 0) {
@@ -120,7 +126,15 @@ struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh, 
	}



	security_d_instantiate(ret, inode);

	spin_lock(&ret->d_lock);

	if (IS_ROOT(ret) && !(ret->d_flags & DCACHE_NFSFS_RENAMED)) {

		ret->d_fsdata = name;

		name = NULL;

	}

	spin_unlock(&ret->d_lock);

out:

	if (name)

		kfree(name);

	nfs_free_fattr(fsinfo.fattr);

	return ret;

}
@@ -177,21 +191,28 @@ struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh, 
	struct nfs_fattr *fattr = NULL;

	struct dentry *ret;

	struct inode *inode;

	void *name = kstrdup(devname, GFP_KERNEL);

	int error;



	dprintk("--> nfs4_get_root()\n");



	if (!name)

		return ERR_PTR(-ENOMEM);



	/* get the info about the server and filesystem */

	error = nfs4_server_capabilities(server, mntfh);

	if (error < 0) {

		dprintk("nfs_get_root: getcaps error = %d\n",

			-error);

		kfree(name);

		return ERR_PTR(error);

	}



	fattr = nfs_alloc_fattr();

	if (fattr == NULL)

		return ERR_PTR(-ENOMEM);;

	if (fattr == NULL) {

		kfree(name);

		return ERR_PTR(-ENOMEM);

	}



	/* get the actual root for this mount */

	error = server->nfs_client->rpc_ops->getattr(server, mntfh, fattr);
@@ -225,8 +246,15 @@ struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh, 
	}



	security_d_instantiate(ret, inode);



	spin_lock(&ret->d_lock);

	if (IS_ROOT(ret) && !(ret->d_flags & DCACHE_NFSFS_RENAMED)) {

		ret->d_fsdata = name;

		name = NULL;

	}

	spin_unlock(&ret->d_lock);

out:

	if (name)

		kfree(name);

	nfs_free_fattr(fattr);

	dprintk("<-- nfs4_get_root()\n");

	return ret;

fs/nfs/unlink.c

+20 −0
Original line number Diff line number Diff line
@@ -148,6 +148,7 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n 
	alias = d_lookup(parent, &data->args.name);

	if (alias != NULL) {

		int ret = 0;

		void *devname_garbage = NULL;



		/*

		 * Hey, we raced with lookup... See if we need to transfer
@@ -157,6 +158,7 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n 
		spin_lock(&alias->d_lock);

		if (alias->d_inode != NULL &&

		    !(alias->d_flags & DCACHE_NFSFS_RENAMED)) {

			devname_garbage = alias->d_fsdata;

			alias->d_fsdata = data;

			alias->d_flags |= DCACHE_NFSFS_RENAMED;

			ret = 1;
@@ -164,6 +166,13 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n 
		spin_unlock(&alias->d_lock);

		nfs_dec_sillycount(dir);

		dput(alias);

		/*

		 * If we'd displaced old cached devname, free it.  At that

		 * point dentry is definitely not a root, so we won't need

		 * that anymore.

		 */

		if (devname_garbage)

			kfree(devname_garbage);

		return ret;

	}

	data->dir = igrab(dir);
@@ -252,6 +261,7 @@ nfs_async_unlink(struct inode *dir, struct dentry *dentry) 
{

	struct nfs_unlinkdata *data;

	int status = -ENOMEM;

	void *devname_garbage = NULL;



	data = kzalloc(sizeof(*data), GFP_KERNEL);

	if (data == NULL)
@@ -269,8 +279,16 @@ nfs_async_unlink(struct inode *dir, struct dentry *dentry) 
	if (dentry->d_flags & DCACHE_NFSFS_RENAMED)

		goto out_unlock;

	dentry->d_flags |= DCACHE_NFSFS_RENAMED;

	devname_garbage = dentry->d_fsdata;

	dentry->d_fsdata = data;

	spin_unlock(&dentry->d_lock);

	/*

	 * If we'd displaced old cached devname, free it.  At that

	 * point dentry is definitely not a root, so we won't need

	 * that anymore.

	 */

	if (devname_garbage)

		kfree(devname_garbage);

	return 0;

out_unlock:

	spin_unlock(&dentry->d_lock);
@@ -299,6 +317,7 @@ nfs_complete_unlink(struct dentry *dentry, struct inode *inode) 
	if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {

		dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;

		data = dentry->d_fsdata;

		dentry->d_fsdata = NULL;

	}

	spin_unlock(&dentry->d_lock);
@@ -315,6 +334,7 @@ nfs_cancel_async_unlink(struct dentry *dentry) 
		struct nfs_unlinkdata *data = dentry->d_fsdata;



		dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;

		dentry->d_fsdata = NULL;

		spin_unlock(&dentry->d_lock);

		nfs_free_unlinkdata(data);

		return;