inode.c

Linux Kernel 2.6.9 for OMAP1710

	buf->f_frsize = server->wtmult;
	buf->f_bsize = sb->s_blocksize;
	blockbits = sb->s_blocksize_bits;
	blockres = (1 << blockbits) - 1;
	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
	buf->f_bavail = (res.abytes + blockres) >> blockbits;
	buf->f_files = res.tfiles;
	buf->f_ffree = res.afiles;

	buf->f_namelen = server->namelen;
 out:
	unlock_kernel();

	return 0;

 out_err:
	printk(KERN_WARNING "nfs_statfs: statfs error = %d\n", -error);
	buf->f_bsize = buf->f_blocks = buf->f_bfree = buf->f_bavail = -1;
	goto out;

}

static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
{
	static struct proc_nfs_info {
		int flag;
		char *str;
		char *nostr;
	} nfs_info[] = {
		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
		{ NFS_MOUNT_INTR, ",intr", "" },
		{ NFS_MOUNT_POSIX, ",posix", "" },
		{ NFS_MOUNT_TCP, ",tcp", ",udp" },
		{ NFS_MOUNT_NOCTO, ",nocto", "" },
		{ NFS_MOUNT_NOAC, ",noac", "" },
		{ NFS_MOUNT_NONLM, ",nolock", ",lock" },
		{ NFS_MOUNT_BROKEN_SUID, ",broken_suid", "" },
		{ 0, NULL, NULL }
	};
	struct proc_nfs_info *nfs_infop;
	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);

	seq_printf(m, ",v%d", nfss->rpc_ops->version);
	seq_printf(m, ",rsize=%d", nfss->rsize);
	seq_printf(m, ",wsize=%d", nfss->wsize);
	if (nfss->acregmin != 3*HZ)
		seq_printf(m, ",acregmin=%d", nfss->acregmin/HZ);
	if (nfss->acregmax != 60*HZ)
		seq_printf(m, ",acregmax=%d", nfss->acregmax/HZ);
	if (nfss->acdirmin != 30*HZ)
		seq_printf(m, ",acdirmin=%d", nfss->acdirmin/HZ);
	if (nfss->acdirmax != 60*HZ)
		seq_printf(m, ",acdirmax=%d", nfss->acdirmax/HZ);
	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
		if (nfss->flags & nfs_infop->flag)
			seq_puts(m, nfs_infop->str);
		else
			seq_puts(m, nfs_infop->nostr);
	}
	seq_puts(m, ",addr=");
	seq_escape(m, nfss->hostname, " \t\n\\");
	return 0;
}

/*
 * Invalidate the local caches
 */
void
nfs_zap_caches(struct inode *inode)
{
	struct nfs_inode *nfsi = NFS_I(inode);
	int mode = inode->i_mode;

	NFS_ATTRTIMEO(inode) = NFS_MINATTRTIMEO(inode);
	NFS_ATTRTIMEO_UPDATE(inode) = jiffies;

	memset(NFS_COOKIEVERF(inode), 0, sizeof(NFS_COOKIEVERF(inode)));
	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))
		nfsi->flags |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
	else
		nfsi->flags |= NFS_INO_INVALID_ATTR;
}

/*
 * Invalidate, but do not unhash, the inode
 */
static void
nfs_invalidate_inode(struct inode *inode)
{
	umode_t save_mode = inode->i_mode;

	make_bad_inode(inode);
	inode->i_mode = save_mode;
	nfs_zap_caches(inode);
}

struct nfs_find_desc {
	struct nfs_fh		*fh;
	struct nfs_fattr	*fattr;
};

/*
 * In NFSv3 we can have 64bit inode numbers. In order to support
 * this, and re-exported directories (also seen in NFSv2)
 * we are forced to allow 2 different inodes to have the same
 * i_ino.
 */
static int
nfs_find_actor(struct inode *inode, void *opaque)
{
	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
	struct nfs_fh		*fh = desc->fh;
	struct nfs_fattr	*fattr = desc->fattr;

	if (NFS_FILEID(inode) != fattr->fileid)
		return 0;
	if (nfs_compare_fh(NFS_FH(inode), fh))
		return 0;
	if (is_bad_inode(inode))
		return 0;
	return 1;
}

static int
nfs_init_locked(struct inode *inode, void *opaque)
{
	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
	struct nfs_fattr	*fattr = desc->fattr;

	NFS_FILEID(inode) = fattr->fileid;
	nfs_copy_fh(NFS_FH(inode), desc->fh);
	return 0;
}

/* Don't use READDIRPLUS on directories that we believe are too large */
#define NFS_LIMIT_READDIRPLUS (8*PAGE_SIZE)

/*
 * This is our front-end to iget that looks up inodes by file handle
 * instead of inode number.
 */
struct inode *
nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
{
	struct nfs_find_desc desc = {
		.fh	= fh,
		.fattr	= fattr
	};
	struct inode *inode = NULL;
	unsigned long hash;

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

	if (!fattr->nlink) {
		printk("NFS: Buggy server - nlink == 0!\n");
		goto out_no_inode;
	}

	hash = nfs_fattr_to_ino_t(fattr);

	if (!(inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc)))
		goto out_no_inode;

	if (inode->i_state & I_NEW) {
		struct nfs_inode *nfsi = NFS_I(inode);

		/* We set i_ino for the few things that still rely on it,
		 * such as stat(2) */
		inode->i_ino = hash;

		/* We can't support update_atime(), since the server will reset it */
		inode->i_flags |= S_NOATIME|S_NOCMTIME;
		inode->i_mode = fattr->mode;
		/* Why so? Because we want revalidate for devices/FIFOs, and
		 * that's precisely what we have in nfs_file_inode_operations.
		 */
		inode->i_op = &nfs_file_inode_operations;
		if (S_ISREG(inode->i_mode)) {
			inode->i_fop = &nfs_file_operations;
			inode->i_data.a_ops = &nfs_file_aops;
			inode->i_data.backing_dev_info = &NFS_SB(sb)->backing_dev_info;
		} else if (S_ISDIR(inode->i_mode)) {
			inode->i_op = NFS_SB(sb)->rpc_ops->dir_inode_ops;
			inode->i_fop = &nfs_dir_operations;
			if (nfs_server_capable(inode, NFS_CAP_READDIRPLUS)
			    && fattr->size <= NFS_LIMIT_READDIRPLUS)
				NFS_FLAGS(inode) |= NFS_INO_ADVISE_RDPLUS;
		} else if (S_ISLNK(inode->i_mode))
			inode->i_op = &nfs_symlink_inode_operations;
		else
			init_special_inode(inode, inode->i_mode, fattr->rdev);

		nfsi->read_cache_jiffies = fattr->timestamp;
		inode->i_atime = fattr->atime;
		inode->i_mtime = fattr->mtime;
		inode->i_ctime = fattr->ctime;
		if (fattr->valid & NFS_ATTR_FATTR_V4)
			nfsi->change_attr = fattr->change_attr;
		inode->i_size = nfs_size_to_loff_t(fattr->size);
		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;
		}
		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
		nfsi->attrtimeo_timestamp = jiffies;
		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
		nfsi->cache_access.cred = NULL;

		unlock_new_inode(inode);
	} else
		nfs_refresh_inode(inode, fattr);
	dprintk("NFS: nfs_fhget(%s/%Ld ct=%d)\n",
		inode->i_sb->s_id,
		(long long)NFS_FILEID(inode),
		atomic_read(&inode->i_count));

out:
	return inode;

out_no_inode:
	printk("nfs_fhget: iget failed\n");
	goto out;
}

#define NFS_VALID_ATTRS (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE|ATTR_ATIME|ATTR_ATIME_SET|ATTR_MTIME|ATTR_MTIME_SET)

int
nfs_setattr(struct dentry *dentry, struct iattr *attr)
{
	struct inode *inode = dentry->d_inode;
	struct nfs_fattr fattr;
	int error;

	if (attr->ia_valid & ATTR_SIZE) {
		if (!S_ISREG(inode->i_mode) || attr->ia_size == i_size_read(inode))
			attr->ia_valid &= ~ATTR_SIZE;
	}

	/* Optimization: if the end result is no change, don't RPC */
	attr->ia_valid &= NFS_VALID_ATTRS;
	if (attr->ia_valid == 0)
		return 0;

	lock_kernel();
	nfs_begin_data_update(inode);
	/* Write all dirty data if we're changing file permissions or size */
	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE)) != 0) {
		if (filemap_fdatawrite(inode->i_mapping) == 0)
			filemap_fdatawait(inode->i_mapping);
		nfs_wb_all(inode);
	}
	error = NFS_PROTO(inode)->setattr(dentry, &fattr, attr);
	if (error == 0) {
		nfs_refresh_inode(inode, &fattr);
		if ((attr->ia_valid & ATTR_MODE) != 0) {
			int mode;
			mode = inode->i_mode & ~S_IALLUGO;
			mode |= attr->ia_mode & S_IALLUGO;
			inode->i_mode = mode;
		}
		if ((attr->ia_valid & ATTR_UID) != 0)
			inode->i_uid = attr->ia_uid;
		if ((attr->ia_valid & ATTR_GID) != 0)
			inode->i_gid = attr->ia_gid;
		if ((attr->ia_valid & ATTR_SIZE) != 0) {
			inode->i_size = attr->ia_size;
			vmtruncate(inode, attr->ia_size);
		}
	}
	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
		struct rpc_cred **cred = &NFS_I(inode)->cache_access.cred;
		if (*cred) {
			put_rpccred(*cred);
			*cred = NULL;
		}
	}
	nfs_end_data_update(inode);
	unlock_kernel();
	return error;
}

/*
 * Wait for the inode to get unlocked.
 * (Used for NFS_INO_LOCKED and NFS_INO_REVALIDATING).
 */
int
nfs_wait_on_inode(struct inode *inode, int flag)
{
	struct rpc_clnt	*clnt = NFS_CLIENT(inode);
	struct nfs_inode *nfsi = NFS_I(inode);

	int error;
	if (!(NFS_FLAGS(inode) & flag))
		return 0;
	atomic_inc(&inode->i_count);
	error = nfs_wait_event(clnt, nfsi->nfs_i_wait,
				!(NFS_FLAGS(inode) & flag));
	iput(inode);
	return error;
}

int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
{
	struct inode *inode = dentry->d_inode;
	struct nfs_inode *nfsi = NFS_I(inode);
	int need_atime = nfsi->flags & NFS_INO_INVALID_ATIME;
	int err;

	if (__IS_FLG(inode, MS_NOATIME))
		need_atime = 0;
	else if (__IS_FLG(inode, MS_NODIRATIME) && S_ISDIR(inode->i_mode))
		need_atime = 0;
	/* We may force a getattr if the user cares about atime */
	if (need_atime)
		err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
	else
		err = nfs_revalidate_inode(NFS_SERVER(inode), inode);
	if (!err)
		generic_fillattr(inode, stat);
	return err;
}

struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, struct rpc_cred *cred)
{
	struct nfs_open_context *ctx;

	ctx = (struct nfs_open_context *)kmalloc(sizeof(*ctx), GFP_KERNEL);
	if (ctx != NULL) {
		atomic_set(&ctx->count, 1);
		ctx->dentry = dget(dentry);
		ctx->cred = get_rpccred(cred);
		ctx->state = NULL;
		ctx->lockowner = current->files;
		ctx->error = 0;
		init_waitqueue_head(&ctx->waitq);
	}
	return ctx;
}

struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
{
	if (ctx != NULL)
		atomic_inc(&ctx->count);
	return ctx;
}

void put_nfs_open_context(struct nfs_open_context *ctx)
{
	if (atomic_dec_and_test(&ctx->count)) {
		if (ctx->state != NULL)
			nfs4_close_state(ctx->state, ctx->mode);
		if (ctx->cred != NULL)
			put_rpccred(ctx->cred);
		dput(ctx->dentry);
		kfree(ctx);
	}
}

/*
 * Ensure that mmap has a recent RPC credential for use when writing out
 * shared pages
 */
void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
{
	struct inode *inode = filp->f_dentry->d_inode;
	struct nfs_inode *nfsi = NFS_I(inode);

	filp->private_data = get_nfs_open_context(ctx);
	spin_lock(&inode->i_lock);
	list_add(&ctx->list, &nfsi->open_files);
	spin_unlock(&inode->i_lock);
}

struct nfs_open_context *nfs_find_open_context(struct inode *inode, int mode)
{
	struct nfs_inode *nfsi = NFS_I(inode);
	struct nfs_open_context *pos, *ctx = NULL;

	spin_lock(&inode->i_lock);
	list_for_each_entry(pos, &nfsi->open_files, list) {
		if ((pos->mode & mode) == mode) {
			ctx = get_nfs_open_context(pos);
			break;
		}
	}
	spin_unlock(&inode->i_lock);
	return ctx;
}

void nfs_file_clear_open_context(struct file *filp)
{
	struct inode *inode = filp->f_dentry->d_inode;
	struct nfs_open_context *ctx = (struct nfs_open_context *)filp->private_data;

	if (ctx) {
		filp->private_data = NULL;
		spin_lock(&inode->i_lock);
		list_del(&ctx->list);
		spin_unlock(&inode->i_lock);
		put_nfs_open_context(ctx);
	}
}

/*
 * These allocate and release file read/write context information.
 */
int nfs_open(struct inode *inode, struct file *filp)
{
	struct nfs_open_context *ctx;
	struct rpc_cred *cred;

	if ((cred = rpcauth_lookupcred(NFS_CLIENT(inode)->cl_auth, 0)) == NULL)
		return -ENOMEM;
	ctx = alloc_nfs_open_context(filp->f_dentry, cred);
	put_rpccred(cred);
	if (ctx == NULL)
		return -ENOMEM;
	ctx->mode = filp->f_mode;
	nfs_file_set_open_context(filp, ctx);
	put_nfs_open_context(ctx);
	if ((filp->f_mode & FMODE_WRITE) != 0)
		nfs_begin_data_update(inode);
	return 0;
}

int nfs_release(struct inode *inode, struct file *filp)
{
	if ((filp->f_mode & FMODE_WRITE) != 0)
		nfs_end_data_update(inode);
	nfs_file_clear_open_context(filp);
	return 0;
}

/*
 * This function is called whenever some part of NFS notices that
 * the cached attributes have to be refreshed.
 */
int
__nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
{
	int		 status = -ESTALE;
	struct nfs_fattr fattr;
	struct nfs_inode *nfsi = NFS_I(inode);
	unsigned long verifier;
	unsigned int flags;

	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Ld)\n",
		inode->i_sb->s_id, (long long)NFS_FILEID(inode));

	lock_kernel();
	if (!inode || is_bad_inode(inode))
 		goto out_nowait;
	if (NFS_STALE(inode) && inode != inode->i_sb->s_root->d_inode)
 		goto out_nowait;

	while (NFS_REVALIDATING(inode)) {
		status = nfs_wait_on_inode(inode, NFS_INO_REVALIDATING);
		if (status < 0)
			goto out_nowait;
		if (NFS_SERVER(inode)->flags & NFS_MOUNT_NOAC)
			continue;
		if (NFS_FLAGS(inode) & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ATIME))
			continue;
		status = NFS_STALE(inode) ? -ESTALE : 0;
		goto out_nowait;
	}
	NFS_FLAGS(inode) |= NFS_INO_REVALIDATING;

	/* Protect against RPC races by saving the change attribute */
	verifier = nfs_save_change_attribute(inode);
	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), &fattr);
	if (status) {
		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Ld) getattr failed, error=%d\n",
			 inode->i_sb->s_id,
			 (long long)NFS_FILEID(inode), status);