inode.c

Linux Kernel 2.6.9 for OMAP1710

		if (status == -ESTALE) {
			NFS_FLAGS(inode) |= NFS_INO_STALE;
			if (inode != inode->i_sb->s_root->d_inode)
				remove_inode_hash(inode);
		}
		goto out;
	}

	status = nfs_update_inode(inode, &fattr, verifier);
	if (status) {
		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) refresh failed, error=%d\n",
			 inode->i_sb->s_id,
			 (long long)NFS_FILEID(inode), status);
		goto out;
	}
	flags = nfsi->flags;
	/*
	 * We may need to keep the attributes marked as invalid if
	 * we raced with nfs_end_attr_update().
	 */
	if (verifier == nfsi->cache_change_attribute)
		nfsi->flags &= ~(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ATIME);
	/* Do the page cache invalidation */
	if (flags & NFS_INO_INVALID_DATA) {
		if (S_ISREG(inode->i_mode)) {
			if (filemap_fdatawrite(inode->i_mapping) == 0)
				filemap_fdatawait(inode->i_mapping);
			nfs_wb_all(inode);
		}
		nfsi->flags &= ~NFS_INO_INVALID_DATA;
		invalidate_inode_pages2(inode->i_mapping);
		memset(NFS_COOKIEVERF(inode), 0, sizeof(NFS_COOKIEVERF(inode)));
		dfprintk(PAGECACHE, "NFS: (%s/%Ld) data cache invalidated\n",
				inode->i_sb->s_id,
				(long long)NFS_FILEID(inode));
		/* This ensures we revalidate dentries */
		nfsi->cache_change_attribute++;
	}
	dfprintk(PAGECACHE, "NFS: (%s/%Ld) revalidation complete\n",
		inode->i_sb->s_id,
		(long long)NFS_FILEID(inode));

	NFS_FLAGS(inode) &= ~NFS_INO_STALE;
out:
	NFS_FLAGS(inode) &= ~NFS_INO_REVALIDATING;
	wake_up(&nfsi->nfs_i_wait);
 out_nowait:
	unlock_kernel();
	return status;
}

int nfs_attribute_timeout(struct inode *inode)
{
	struct nfs_inode *nfsi = NFS_I(inode);

	if (nfs_have_delegation(inode, FMODE_READ))
		return 0;
	return time_after(jiffies, nfsi->read_cache_jiffies+nfsi->attrtimeo);
}

/**
 * nfs_revalidate_inode - Revalidate the inode attributes
 * @server - pointer to nfs_server struct
 * @inode - pointer to inode struct
 *
 * Updates inode attribute information by retrieving the data from the server.
 */
int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
{
	if (!(NFS_FLAGS(inode) & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))
			&& !nfs_attribute_timeout(inode))
		return NFS_STALE(inode) ? -ESTALE : 0;
	return __nfs_revalidate_inode(server, inode);
}

/**
 * nfs_begin_data_update
 * @inode - pointer to inode
 * Declare that a set of operations will update file data on the server
 */
void nfs_begin_data_update(struct inode *inode)
{
	atomic_inc(&NFS_I(inode)->data_updates);
}

/**
 * nfs_end_data_update
 * @inode - pointer to inode
 * Declare end of the operations that will update file data
 * This will mark the inode as immediately needing revalidation
 * of its attribute cache.
 */
void nfs_end_data_update(struct inode *inode)
{
	struct nfs_inode *nfsi = NFS_I(inode);

	if (!nfs_have_delegation(inode, FMODE_READ)) {
		/* Mark the attribute cache for revalidation */
		nfsi->flags |= NFS_INO_INVALID_ATTR;
		/* Directories and symlinks: invalidate page cache too */
		if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
			nfsi->flags |= NFS_INO_INVALID_DATA;
	}
	nfsi->cache_change_attribute ++;
	atomic_dec(&nfsi->data_updates);
}

/**
 * nfs_end_data_update_defer
 * @inode - pointer to inode
 * Declare end of the operations that will update file data
 * This will defer marking the inode as needing revalidation
 * unless there are no other pending updates.
 */
void nfs_end_data_update_defer(struct inode *inode)
{
	struct nfs_inode *nfsi = NFS_I(inode);

	if (atomic_dec_and_test(&nfsi->data_updates)) {
		/* Mark the attribute cache for revalidation */
		nfsi->flags |= NFS_INO_INVALID_ATTR;
		/* Directories and symlinks: invalidate page cache too */
		if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
			nfsi->flags |= NFS_INO_INVALID_DATA;
		nfsi->cache_change_attribute ++;
	}
}

/**
 * nfs_refresh_inode - verify consistency of the inode attribute cache
 * @inode - pointer to inode
 * @fattr - updated attributes
 *
 * Verifies the attribute cache. If we have just changed the attributes,
 * so that fattr carries weak cache consistency data, then it may
 * also update the ctime/mtime/change_attribute.
 */
int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
{
	struct nfs_inode *nfsi = NFS_I(inode);
	loff_t cur_size, new_isize;
	int data_unstable;

	/* Do we hold a delegation? */
	if (nfs_have_delegation(inode, FMODE_READ))
		return 0;

	/* Are we in the process of updating data on the server? */
	data_unstable = nfs_caches_unstable(inode);

	if (fattr->valid & NFS_ATTR_FATTR_V4) {
		if ((fattr->valid & NFS_ATTR_PRE_CHANGE) != 0
				&& nfsi->change_attr == fattr->pre_change_attr)
			nfsi->change_attr = fattr->change_attr;
		if (!data_unstable && nfsi->change_attr != fattr->change_attr)
			nfsi->flags |= NFS_INO_INVALID_ATTR;
	}

	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
		return 0;

	/* Has the inode gone and changed behind our back? */
	if (nfsi->fileid != fattr->fileid
			|| (inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
		return -EIO;

	cur_size = i_size_read(inode);
 	new_isize = nfs_size_to_loff_t(fattr->size);

	/* If we have atomic WCC data, we may update some attributes */
	if ((fattr->valid & NFS_ATTR_WCC) != 0) {
		if (timespec_equal(&inode->i_ctime, &fattr->pre_ctime))
			memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
		if (timespec_equal(&inode->i_mtime, &fattr->pre_mtime))
			memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
	}

	/* Verify a few of the more important attributes */
	if (!data_unstable) {
		if (!timespec_equal(&inode->i_mtime, &fattr->mtime)
				|| cur_size != new_isize)
			nfsi->flags |= NFS_INO_INVALID_ATTR;
	} else if (S_ISREG(inode->i_mode) && new_isize > cur_size)
			nfsi->flags |= NFS_INO_INVALID_ATTR;

	/* Have any file permissions changed? */
	if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)
			|| inode->i_uid != fattr->uid
			|| inode->i_gid != fattr->gid)
		nfsi->flags |= NFS_INO_INVALID_ATTR;

	/* Has the link count changed? */
	if (inode->i_nlink != fattr->nlink)
		nfsi->flags |= NFS_INO_INVALID_ATTR;

	if (!timespec_equal(&inode->i_atime, &fattr->atime))
		nfsi->flags |= NFS_INO_INVALID_ATIME;

	nfsi->read_cache_jiffies = fattr->timestamp;
	return 0;
}

/*
 * Many nfs protocol calls return the new file attributes after
 * an operation.  Here we update the inode to reflect the state
 * of the server's inode.
 *
 * This is a bit tricky because we have to make sure all dirty pages
 * have been sent off to the server before calling invalidate_inode_pages.
 * To make sure no other process adds more write requests while we try
 * our best to flush them, we make them sleep during the attribute refresh.
 *
 * A very similar scenario holds for the dir cache.
 */
static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr, unsigned long verifier)
{
	struct nfs_inode *nfsi = NFS_I(inode);
	__u64		new_size;
	loff_t		new_isize;
	unsigned int	invalid = 0;
	loff_t		cur_isize;
	int data_unstable;

	dfprintk(VFS, "NFS: %s(%s/%ld ct=%d info=0x%x)\n",
			__FUNCTION__, inode->i_sb->s_id, inode->i_ino,
			atomic_read(&inode->i_count), fattr->valid);

	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
		return 0;

	if (nfsi->fileid != fattr->fileid) {
		printk(KERN_ERR "%s: inode number mismatch\n"
		       "expected (%s/0x%Lx), got (%s/0x%Lx)\n",
		       __FUNCTION__,
		       inode->i_sb->s_id, (long long)nfsi->fileid,
		       inode->i_sb->s_id, (long long)fattr->fileid);
		goto out_err;
	}

	/*
	 * Make sure the inode's type hasn't changed.
	 */
	if ((inode->i_mode & S_IFMT) != (fattr->mode & S_IFMT))
		goto out_changed;

	/*
	 * Update the read time so we don't revalidate too often.
	 */
	nfsi->read_cache_jiffies = fattr->timestamp;

	/* Are we racing with known updates of the metadata on the server? */
	data_unstable = ! nfs_verify_change_attribute(inode, verifier);

	/* Check if the file size agrees */
	new_size = fattr->size;
 	new_isize = nfs_size_to_loff_t(fattr->size);
	cur_isize = i_size_read(inode);
	if (cur_isize != new_size) {
#ifdef NFS_DEBUG_VERBOSE
		printk(KERN_DEBUG "NFS: isize change on %s/%ld\n", inode->i_sb->s_id, inode->i_ino);
#endif
		/*
		 * If we have pending writebacks, things can get
		 * messy.
		 */
		if (S_ISREG(inode->i_mode) && data_unstable) {
			if (new_isize > cur_isize) {
				inode->i_size = new_isize;
				invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
			}
		} else {
			inode->i_size = new_isize;
			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
		}
	}

	/*
	 * Note: we don't check inode->i_mtime since pipes etc.
	 *       can change this value in VFS without requiring a
	 *	 cache revalidation.
	 */
	if (!timespec_equal(&inode->i_mtime, &fattr->mtime)) {
		memcpy(&inode->i_mtime, &fattr->mtime, sizeof(inode->i_mtime));
#ifdef NFS_DEBUG_VERBOSE
		printk(KERN_DEBUG "NFS: mtime change on %s/%ld\n", inode->i_sb->s_id, inode->i_ino);
#endif
		if (!data_unstable)
			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
	}

	if ((fattr->valid & NFS_ATTR_FATTR_V4)
	    && nfsi->change_attr != fattr->change_attr) {
#ifdef NFS_DEBUG_VERBOSE
		printk(KERN_DEBUG "NFS: change_attr change on %s/%ld\n",
		       inode->i_sb->s_id, inode->i_ino);
#endif
		nfsi->change_attr = fattr->change_attr;
		if (!data_unstable)
			invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
	}

	memcpy(&inode->i_ctime, &fattr->ctime, sizeof(inode->i_ctime));
	memcpy(&inode->i_atime, &fattr->atime, sizeof(inode->i_atime));

	if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO) ||
	    inode->i_uid != fattr->uid ||
	    inode->i_gid != fattr->gid) {
		struct rpc_cred **cred = &NFS_I(inode)->cache_access.cred;
		if (*cred) {
			put_rpccred(*cred);
			*cred = NULL;
		}
		invalid |= NFS_INO_INVALID_ATTR;
	}

	inode->i_mode = fattr->mode;
	inode->i_nlink = fattr->nlink;
	inode->i_uid = fattr->uid;
	inode->i_gid = fattr->gid;

	if (fattr->valid & (NFS_ATTR_FATTR_V3 | NFS_ATTR_FATTR_V4)) {
		/*
		 * report the blocks in 512byte units
		 */
		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
		inode->i_blksize = inode->i_sb->s_blocksize;
 	} else {
 		inode->i_blocks = fattr->du.nfs2.blocks;
 		inode->i_blksize = fattr->du.nfs2.blocksize;
 	}

	/* Update attrtimeo value if we're out of the unstable period */
	if (invalid & NFS_INO_INVALID_ATTR) {
		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
		nfsi->attrtimeo_timestamp = jiffies;
	} else if (time_after(jiffies, nfsi->attrtimeo_timestamp+nfsi->attrtimeo)) {
		if ((nfsi->attrtimeo <<= 1) > NFS_MAXATTRTIMEO(inode))
			nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
		nfsi->attrtimeo_timestamp = jiffies;
	}
	/* Don't invalidate the data if we were to blame */
	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
				|| S_ISLNK(inode->i_mode)))
		invalid &= ~NFS_INO_INVALID_DATA;
	if (!nfs_have_delegation(inode, FMODE_READ))
		nfsi->flags |= invalid;

	return 0;
 out_changed:
	/*
	 * Big trouble! The inode has become a different object.
	 */
#ifdef NFS_PARANOIA
	printk(KERN_DEBUG "%s: inode %ld mode changed, %07o to %07o\n",
			__FUNCTION__, inode->i_ino, inode->i_mode, fattr->mode);
#endif
	/*
	 * No need to worry about unhashing the dentry, as the
	 * lookup validation will know that the inode is bad.
	 * (But we fall through to invalidate the caches.)
	 */
	nfs_invalidate_inode(inode);
 out_err:
	return -EIO;
}

/*
 * File system information
 */

static int nfs_set_super(struct super_block *s, void *data)
{
	s->s_fs_info = data;
	return set_anon_super(s, data);
}
 
static int nfs_compare_super(struct super_block *sb, void *data)
{
	struct nfs_server *server = data;
	struct nfs_server *old = NFS_SB(sb);

	if (old->addr.sin_addr.s_addr != server->addr.sin_addr.s_addr)
		return 0;
	if (old->addr.sin_port != server->addr.sin_port)
		return 0;
	return !nfs_compare_fh(&old->fh, &server->fh);
}

static struct super_block *nfs_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *raw_data)
{
	int error;
	struct nfs_server *server;
	struct super_block *s;
	struct nfs_fh *root;
	struct nfs_mount_data *data = raw_data;

	if (!data) {
		printk("nfs_read_super: missing data argument\n");
		return ERR_PTR(-EINVAL);
	}

	server = kmalloc(sizeof(struct nfs_server), GFP_KERNEL);
	if (!server)
		return ERR_PTR(-ENOMEM);
	memset(server, 0, sizeof(struct nfs_server));
	/* Zero out the NFS state stuff */
	init_nfsv4_state(server);

	if (data->version != NFS_MOUNT_VERSION) {
		printk("nfs warning: mount version %s than kernel\n",
			data->version < NFS_MOUNT_VERSION ? "older" : "newer");
		if (data->version < 2)
			data->namlen = 0;
		if (data->version < 3)
			data->bsize  = 0;
		if (data->version < 4) {
			data->flags &= ~NFS_MOUNT_VER3;
			data->root.size = NFS2_FHSIZE;
			memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
		}
		if (data->version < 5)
			data->flags &= ~NFS_MOUNT_SECFLAVOUR;
	}

	root = &server->fh;
	if (data->flags & NFS_MOUNT_VER3)
		root->size = data->root.size;
	else
		root->size = NFS2_FHSIZE;
	if (root->size > sizeof(root->data)) {
		printk("nfs_get_sb: invalid root filehandle\n");
		kfree(server);
		return ERR_PTR(-EINVAL);
	}
	memcpy(root->data, data->root.data, root->size);

	/* We now require that the mount process passes the remote address */
	memcpy(&server->addr, &data->addr, sizeof(server->addr));
	if (server->addr.sin_addr.s_addr == INADDR_ANY) {
		printk("NFS: mount program didn't pass remote address!\n");
		kfree(server);
		return ERR_PTR(-EINVAL);
	}

	s = sget(fs_type, nfs_compare_super, nfs_set_super, server);

	if (IS_ERR(s) || s->s_root) {
		kfree(server);
		return s;
	}

	s->s_flags = flags;

	/* Fire up rpciod if not yet running */
	if (rpciod_up() != 0) {
		printk(KERN_WARNING "NFS: couldn't start rpciod!\n");
		kfree(server);
		return ERR_PTR(-EIO);
	}

	error = nfs_fill_super(s, data, flags & MS_VERBOSE ? 1 : 0);
	if (error) {
		up_write(&s->s_umount);
		deactivate_super(s);
		return ERR_PTR(error);
	}
	s->s_flags |= MS_ACTIVE;
	return s;
}

static void nfs_kill_super(struct super_block *s)
{
	struct nfs_server *server = NFS_SB(s);

	kill_anon_super(s);

	nfs4_renewd_prepare_shutdown(server);

	if (server->client != NULL && !IS_ERR(server->client))
		rpc_shutdown_client(server->client);
	if (server->client_sys != NULL && !IS_ERR(server->client_sys))
		rpc_shutdown_client(server->client_sys);

	if (!(server->flags & NFS_MOUNT_NONLM))
		lockd_down();	/* release rpc.lockd */