Commit 0d0def49 authored by Al Viro's avatar Al Viro
Browse files

teach nfs_get_link() to work in RCU mode 



based upon the corresponding patch from Neil's March patchset,
again with kmap-related horrors removed.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 1a384eaa

fs/nfs/inode.c

+21 −0
Original line number Diff line number Diff line
@@ -1087,6 +1087,27 @@ static bool nfs_mapping_need_revalidate_inode(struct inode *inode) 
		|| NFS_STALE(inode);

}



int nfs_revalidate_mapping_rcu(struct inode *inode)

{

	struct nfs_inode *nfsi = NFS_I(inode);

	unsigned long *bitlock = &nfsi->flags;

	int ret = 0;



	if (IS_SWAPFILE(inode))

		goto out;

	if (nfs_mapping_need_revalidate_inode(inode)) {

		ret = -ECHILD;

		goto out;

	}

	spin_lock(&inode->i_lock);

	if (test_bit(NFS_INO_INVALIDATING, bitlock) ||

	    (nfsi->cache_validity & NFS_INO_INVALID_DATA))

		ret = -ECHILD;

	spin_unlock(&inode->i_lock);

out:

	return ret;

}



/**

 * __nfs_revalidate_mapping - Revalidate the pagecache

 * @inode - pointer to host inode

fs/nfs/symlink.c

+20 −10
Original line number Diff line number Diff line
@@ -48,9 +48,18 @@ static const char *nfs_get_link(struct dentry *dentry, 
	struct page *page;

	void *err;



	if (!dentry)

	if (!dentry) {

		err = ERR_PTR(nfs_revalidate_mapping_rcu(inode));

		if (err)

			return err;

		page = find_get_page(inode->i_mapping, 0);

		if (!page)

			return ERR_PTR(-ECHILD);



		if (!PageUptodate(page)) {

			put_page(page);

			return ERR_PTR(-ECHILD);

		}

	} else {

		err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping));

		if (err)

			return err;
@@ -58,6 +67,7 @@ static const char *nfs_get_link(struct dentry *dentry, 
					(filler_t *)nfs_symlink_filler, inode);

		if (IS_ERR(page))

			return ERR_CAST(page);

	}

	*cookie = page;

	return page_address(page);

}

include/linux/nfs_fs.h

+1 −0
Original line number Diff line number Diff line
@@ -359,6 +359,7 @@ extern int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode); 
extern int nfs_revalidate_inode_rcu(struct nfs_server *server, struct inode *inode);

extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);

extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping);

extern int nfs_revalidate_mapping_rcu(struct inode *inode);

extern int nfs_revalidate_mapping_protected(struct inode *inode, struct address_space *mapping);

extern int nfs_setattr(struct dentry *, struct iattr *);

extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr, struct nfs_fattr *);