NFS: Add fs_context support.

Add filesystem context support to NFS, parsing the options in advance and
attaching the information to struct nfs_fs_context.  The highlights are:

 (*) Merge nfs_mount_info and nfs_clone_mount into nfs_fs_context.  This
     structure represents NFS's superblock config.

 (*) Make use of the VFS's parsing support to split comma-separated lists

 (*) Pin the NFS protocol module in the nfs_fs_context.

 (*) Attach supplementary error information to fs_context.  This has the
     downside that these strings must be static and can't be formatted.

 (*) Remove the auxiliary file_system_type structs since the information
     necessary can be conveyed in the nfs_fs_context struct instead.

 (*) Root mounts are made by duplicating the config for the requested mount
     so as to have the same parameters.  Submounts pick up their parameters
     from the parent superblock.

[AV -- retrans is u32, not string]
[SM -- Renamed cfg to ctx in a few functions in an earlier patch]
[SM -- Moved fs_context mount option parsing to an earlier patch]
[SM -- Moved fs_context error logging to a later patch]
[SM -- Fixed printks in nfs4_try_get_tree() and nfs4_get_referral_tree()]
[SM -- Added is_remount_fc() helper]
[SM -- Deferred some refactoring to a later patch]
[SM -- Fixed referral mounts, which were broken in the original patch]
[SM -- Fixed leak of nfs_fattr when fs_context is freed]

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This commit is contained in:
David Howells 2019-12-10 07:31:13 -05:00 committed by Anna Schumaker
parent e38bb238ed
commit f2aedb713c
12 changed files with 778 additions and 664 deletions

View file

@ -1639,6 +1639,7 @@ struct nfs_subversion;
struct nfs_mount_info;
struct nfs_client_initdata;
struct nfs_pageio_descriptor;
struct fs_context;
/*
* RPC procedure vector for NFSv2/NFSv3 demuxing
@ -1653,9 +1654,8 @@ struct nfs_rpc_ops {
int (*getroot) (struct nfs_server *, struct nfs_fh *,
struct nfs_fsinfo *);
struct vfsmount *(*submount) (struct nfs_server *, struct dentry *,
struct nfs_fh *, struct nfs_fattr *);
struct dentry *(*try_mount) (int, const char *, struct nfs_mount_info *);
int (*submount) (struct fs_context *, struct nfs_server *);
int (*try_get_tree) (struct fs_context *);
int (*getattr) (struct nfs_server *, struct nfs_fh *,
struct nfs_fattr *, struct nfs4_label *,
struct inode *);