From 304e9c83e80d5cbe20ab64ffa1fac9fc51d30bc9 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Tue, 2 May 2023 15:48:15 +0300 Subject: exportfs: add explicit flag to request non-decodeable file handles So far, all callers of exportfs_encode_inode_fh(), except for fsnotify's show_mark_fhandle(), check that filesystem can decode file handles, but we would like to add more callers that do not require a file handle that can be decoded. Introduce a flag to explicitly request a file handle that may not to be decoded later and a wrapper exportfs_encode_fid() that sets this flag and convert show_mark_fhandle() to use the new wrapper. This will be used to allow adding fanotify support to filesystems that do not support NFS export. Acked-by: Jeff Layton Acked-by: Chuck Lever Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara Message-Id: <20230502124817.3070545-3-amir73il@gmail.com> --- fs/exportfs/expfs.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) (limited to 'fs/exportfs') diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c index ab7feffe2d19..40e624cf7e92 100644 --- a/fs/exportfs/expfs.c +++ b/fs/exportfs/expfs.c @@ -381,11 +381,27 @@ static int export_encode_fh(struct inode *inode, struct fid *fid, return type; } +/** + * exportfs_encode_inode_fh - encode a file handle from inode + * @inode: the object to encode + * @fid: where to store the file handle fragment + * @max_len: maximum length to store there + * @flags: properties of the requested file handle + * + * Returns an enum fid_type or a negative errno. + */ int exportfs_encode_inode_fh(struct inode *inode, struct fid *fid, - int *max_len, struct inode *parent) + int *max_len, struct inode *parent, int flags) { const struct export_operations *nop = inode->i_sb->s_export_op; + /* + * If a decodeable file handle was requested, we need to make sure that + * filesystem can decode file handles. + */ + if (nop && !(flags & EXPORT_FH_FID) && !nop->fh_to_dentry) + return -EOPNOTSUPP; + if (nop && nop->encode_fh) return nop->encode_fh(inode, fid->raw, max_len, parent); @@ -418,7 +434,7 @@ int exportfs_encode_fh(struct dentry *dentry, struct fid *fid, int *max_len, parent = p->d_inode; } - error = exportfs_encode_inode_fh(inode, fid, max_len, parent); + error = exportfs_encode_inode_fh(inode, fid, max_len, parent, flags); dput(p); return error; -- cgit v1.2.3-73-gaa49b