summaryrefslogtreecommitdiffstats
path: root/fs/nfs/export.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/nfs/export.c')
-rw-r--r--fs/nfs/export.c158
1 files changed, 158 insertions, 0 deletions
diff --git a/fs/nfs/export.c b/fs/nfs/export.c
new file mode 100644
index 0000000000..be686b8e0c
--- /dev/null
+++ b/fs/nfs/export.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2015, Primary Data, Inc. All rights reserved.
+ *
+ * Tao Peng <bergwolf@primarydata.com>
+ */
+#include <linux/dcache.h>
+#include <linux/exportfs.h>
+#include <linux/nfs.h>
+#include <linux/nfs_fs.h>
+
+#include "internal.h"
+#include "nfstrace.h"
+
+#define NFSDBG_FACILITY NFSDBG_VFS
+
+enum {
+ FILEID_HIGH_OFF = 0, /* inode fileid high */
+ FILEID_LOW_OFF, /* inode fileid low */
+ FILE_I_TYPE_OFF, /* inode type */
+ EMBED_FH_OFF /* embeded server fh */
+};
+
+
+static struct nfs_fh *nfs_exp_embedfh(__u32 *p)
+{
+ return (struct nfs_fh *)(p + EMBED_FH_OFF);
+}
+
+/*
+ * Let's break subtree checking for now... otherwise we'll have to embed parent fh
+ * but there might not be enough space.
+ */
+static int
+nfs_encode_fh(struct inode *inode, __u32 *p, int *max_len, struct inode *parent)
+{
+ struct nfs_fh *server_fh = NFS_FH(inode);
+ struct nfs_fh *clnt_fh = nfs_exp_embedfh(p);
+ size_t fh_size = offsetof(struct nfs_fh, data) + server_fh->size;
+ int len = EMBED_FH_OFF + XDR_QUADLEN(fh_size);
+
+ dprintk("%s: max fh len %d inode %p parent %p",
+ __func__, *max_len, inode, parent);
+
+ if (*max_len < len) {
+ dprintk("%s: fh len %d too small, required %d\n",
+ __func__, *max_len, len);
+ *max_len = len;
+ return FILEID_INVALID;
+ }
+
+ p[FILEID_HIGH_OFF] = NFS_FILEID(inode) >> 32;
+ p[FILEID_LOW_OFF] = NFS_FILEID(inode);
+ p[FILE_I_TYPE_OFF] = inode->i_mode & S_IFMT;
+ p[len - 1] = 0; /* Padding */
+ nfs_copy_fh(clnt_fh, server_fh);
+ *max_len = len;
+ dprintk("%s: result fh fileid %llu mode %u size %d\n",
+ __func__, NFS_FILEID(inode), inode->i_mode, *max_len);
+ return *max_len;
+}
+
+static struct dentry *
+nfs_fh_to_dentry(struct super_block *sb, struct fid *fid,
+ int fh_len, int fh_type)
+{
+ struct nfs_fattr *fattr = NULL;
+ struct nfs_fh *server_fh = nfs_exp_embedfh(fid->raw);
+ size_t fh_size = offsetof(struct nfs_fh, data) + server_fh->size;
+ const struct nfs_rpc_ops *rpc_ops;
+ struct dentry *dentry;
+ struct inode *inode;
+ int len = EMBED_FH_OFF + XDR_QUADLEN(fh_size);
+ u32 *p = fid->raw;
+ int ret;
+
+ /* NULL translates to ESTALE */
+ if (fh_len < len || fh_type != len)
+ return NULL;
+
+ fattr = nfs_alloc_fattr_with_label(NFS_SB(sb));
+ if (fattr == NULL) {
+ dentry = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+
+ fattr->fileid = ((u64)p[FILEID_HIGH_OFF] << 32) + p[FILEID_LOW_OFF];
+ fattr->mode = p[FILE_I_TYPE_OFF];
+ fattr->valid |= NFS_ATTR_FATTR_FILEID | NFS_ATTR_FATTR_TYPE;
+
+ dprintk("%s: fileid %llu mode %d\n", __func__, fattr->fileid, fattr->mode);
+
+ inode = nfs_ilookup(sb, fattr, server_fh);
+ if (inode)
+ goto out_found;
+
+ rpc_ops = NFS_SB(sb)->nfs_client->rpc_ops;
+ ret = rpc_ops->getattr(NFS_SB(sb), server_fh, fattr, NULL);
+ if (ret) {
+ dprintk("%s: getattr failed %d\n", __func__, ret);
+ trace_nfs_fh_to_dentry(sb, server_fh, fattr->fileid, ret);
+ dentry = ERR_PTR(ret);
+ goto out_free_fattr;
+ }
+
+ inode = nfs_fhget(sb, server_fh, fattr);
+
+out_found:
+ dentry = d_obtain_alias(inode);
+out_free_fattr:
+ nfs_free_fattr(fattr);
+out:
+ return dentry;
+}
+
+static struct dentry *
+nfs_get_parent(struct dentry *dentry)
+{
+ int ret;
+ struct inode *inode = d_inode(dentry), *pinode;
+ struct super_block *sb = inode->i_sb;
+ struct nfs_server *server = NFS_SB(sb);
+ struct nfs_fattr *fattr = NULL;
+ struct dentry *parent;
+ struct nfs_rpc_ops const *ops = server->nfs_client->rpc_ops;
+ struct nfs_fh fh;
+
+ if (!ops->lookupp)
+ return ERR_PTR(-EACCES);
+
+ fattr = nfs_alloc_fattr_with_label(server);
+ if (fattr == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ ret = ops->lookupp(inode, &fh, fattr);
+ if (ret) {
+ parent = ERR_PTR(ret);
+ goto out;
+ }
+
+ pinode = nfs_fhget(sb, &fh, fattr);
+ parent = d_obtain_alias(pinode);
+out:
+ nfs_free_fattr(fattr);
+ return parent;
+}
+
+const struct export_operations nfs_export_ops = {
+ .encode_fh = nfs_encode_fh,
+ .fh_to_dentry = nfs_fh_to_dentry,
+ .get_parent = nfs_get_parent,
+ .flags = EXPORT_OP_NOWCC |
+ EXPORT_OP_NOSUBTREECHK |
+ EXPORT_OP_CLOSE_BEFORE_UNLINK |
+ EXPORT_OP_REMOTE_FS |
+ EXPORT_OP_NOATOMIC_ATTR |
+ EXPORT_OP_FLUSH_ON_CLOSE,
+};