From: Miklos Szeredi <miklos@szeredi.hu>
This patch adds support for exporting a FUSE filesystem through NFS.
The following export operations are defined:
o get_dentry
o encode_fh
Currently only inodes still in the cache are found. This is adequate
for most applications.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
fs/fuse/inode.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 62 insertions(+)
diff -puN fs/fuse/inode.c~fuse-nfs-export fs/fuse/inode.c
--- 25/fs/fuse/inode.c~fuse-nfs-export 2005-05-10 02:22:07.000000000 -0700
+++ 25-akpm/fs/fuse/inode.c 2005-05-10 02:22:07.000000000 -0700
@@ -438,6 +438,67 @@ static struct inode *get_root_inode(stru
return fuse_iget(sb, 1, 0, &attr);
}
+static struct dentry *fuse_get_dentry(struct super_block *sb, void *vobjp)
+{
+ __u32 *objp = vobjp;
+ unsigned long nodeid = objp[0];
+ __u32 generation = objp[1];
+ struct inode *inode;
+ struct dentry *entry;
+
+ if (nodeid == 0)
+ return ERR_PTR(-ESTALE);
+
+ inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
+ if (!inode)
+ return ERR_PTR(-ESTALE);
+ if (inode->i_generation != generation) {
+ iput(inode);
+ return ERR_PTR(-ESTALE);
+ }
+
+ entry = d_alloc_anon(inode);
+ if (!entry) {
+ iput(inode);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ return entry;
+}
+
+static int fuse_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len,
+ int connectable)
+{
+ struct inode *inode = dentry->d_inode;
+ int len = *max_len;
+ int type = 1;
+
+ if (len < 2 || (connectable && len < 4))
+ return 255;
+
+ len = 2;
+ fh[0] = get_fuse_inode(inode)->nodeid;
+ fh[1] = inode->i_generation;
+ if (connectable && !S_ISDIR(inode->i_mode)) {
+ struct inode *parent;
+
+ spin_lock(&dentry->d_lock);
+ parent = dentry->d_parent->d_inode;
+ fh[2] = get_fuse_inode(parent)->nodeid;
+ fh[3] = parent->i_generation;
+ spin_unlock(&dentry->d_lock);
+ len = 4;
+ type = 2;
+ }
+ *max_len = len;
+ return type;
+}
+
+static struct export_operations fuse_export_operations = {
+ .get_dentry = fuse_get_dentry,
+ .encode_fh = fuse_encode_fh,
+};
+
static struct super_operations fuse_super_operations = {
.alloc_inode = fuse_alloc_inode,
.destroy_inode = fuse_destroy_inode,
@@ -464,6 +525,7 @@ static int fuse_fill_super(struct super_
sb->s_magic = FUSE_SUPER_MAGIC;
sb->s_op = &fuse_super_operations;
sb->s_maxbytes = MAX_LFS_FILESIZE;
+ sb->s_export_op = &fuse_export_operations;
file = fget(d.fd);
if (!file)
_