the subject is unsuitable? i mean the prefix should be fs/ramfs rather than knfsd?
2019-05-22 3:25 GMT+12:00, Haodong Wong <[email protected]>: > Refer to tmpfs, use inode number and generation number > to construct the filehandle for nfs-export would you like to describe what is happening without this patch? BTW, i guess you can keep Andrew Morton in the loop to review the patch when you resend it. > > Signed-off-by: Haodong Wong <[email protected]> > --- > fs/ramfs/inode.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 72 insertions(+) > > diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c > index 11201b2d06b9..418b2551f6fd 100644 > --- a/fs/ramfs/inode.c > +++ b/fs/ramfs/inode.c > @@ -36,6 +36,7 @@ > #include <linux/magic.h> > #include <linux/slab.h> > #include <linux/uaccess.h> > +#include <linux/exportfs.h> > #include "internal.h" > > struct ramfs_mount_opts { > @@ -66,6 +67,7 @@ struct inode *ramfs_get_inode(struct super_block *sb, > if (inode) { > inode->i_ino = get_next_ino(); > inode_init_owner(inode, dir, mode); > + inode->i_generation = get_seconds(); > inode->i_mapping->a_ops = &ramfs_aops; > mapping_set_gfp_mask(inode->i_mapping, GFP_HIGHUSER); > mapping_set_unevictable(inode->i_mapping); > @@ -217,6 +219,75 @@ static int ramfs_parse_options(char *data, struct > ramfs_mount_opts *opts) > return 0; > } > > +static struct dentry *ramfs_get_parent(struct dentry *child) > +{ > + return ERR_PTR(-ESTALE); > +} > + > +static int ramfs_match(struct inode *ino, void *vfh) > +{ > + __u32 *fh = vfh; > + __u64 inum = fh[2]; > + > + inum = (inum << 32) | fh[1]; > + return ino->i_ino == inum && fh[0] == ino->i_generation; > +} > + > +static struct dentry *ramfs_fh_to_dentry(struct super_block *sb, > + struct fid *fid, int fh_len, int fh_type) > + > +{ > + struct inode *inode; > + struct dentry *dentry = NULL; > + u64 inum; > + > + if (fh_len < 3) > + return NULL; > + > + inum = fid->raw[2]; > + inum = (inum << 32) | fid->raw[1]; > + inode = ilookup5(sb, (unsigned long)(inum + fid->raw[0]), > + ramfs_match, fid->raw); > + > + if (inode) { > + dentry = d_find_alias(inode); > + iput(inode); > + } > + > + return dentry; > +} > + > +static int ramfs_encode_fh(struct inode *inode, __u32 *fh, int *len, > + struct inode *parent) > +{ > + if (*len < 3) { > + *len = 3; > + return FILEID_INVALID; > + } > + > + if (inode_unhashed(inode)) { > + static DEFINE_SPINLOCK(lock); > + > + spin_lock(&lock); > + if (inode_unhashed(inode)) > + __insert_inode_hash(inode, > + inode->i_ino + inode->i_generation); > + spin_unlock(&lock); > + } > + fh[0] = inode->i_generation; > + fh[1] = inode->i_ino; > + fh[2] = ((__u64)inode->i_ino) >> 32; > + > + *len = 3; > + return 1; > +} > + > +static const struct export_operations ramfs_export_ops = { > + .get_parent = ramfs_get_parent, > + .encode_fh = ramfs_encode_fh, > + .fh_to_dentry = ramfs_fh_to_dentry, > +}; > + > int ramfs_fill_super(struct super_block *sb, void *data, int silent) > { > struct ramfs_fs_info *fsi; > @@ -238,6 +309,7 @@ int ramfs_fill_super(struct super_block *sb, void *data, > int silent) > sb->s_magic = RAMFS_MAGIC; > sb->s_op = &ramfs_ops; > sb->s_time_gran = 1; > + sb->s_export_op = &ramfs_export_ops; > > inode = ramfs_get_inode(sb, NULL, S_IFDIR | fsi->mount_opts.mode, 0); > sb->s_root = d_make_root(inode); > -- > 2.17.1 > > -barry
