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linux/fs/nfsd/nfsproc.c
Linus Torvalds 7d6beb71da idmapped-mounts-v5.12 
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Merge tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull idmapped mounts from Christian Brauner:
 "This introduces idmapped mounts which has been in the making for some
  time. Simply put, different mounts can expose the same file or
  directory with different ownership. This initial implementation comes
  with ports for fat, ext4 and with Christoph's port for xfs with more
  filesystems being actively worked on by independent people and
  maintainers.

  Idmapping mounts handle a wide range of long standing use-cases. Here
  are just a few:

   - Idmapped mounts make it possible to easily share files between
     multiple users or multiple machines especially in complex
     scenarios. For example, idmapped mounts will be used in the
     implementation of portable home directories in
     systemd-homed.service(8) where they allow users to move their home
     directory to an external storage device and use it on multiple
     computers where they are assigned different uids and gids. This
     effectively makes it possible to assign random uids and gids at
     login time.

   - It is possible to share files from the host with unprivileged
     containers without having to change ownership permanently through
     chown(2).

   - It is possible to idmap a container's rootfs and without having to
     mangle every file. For example, Chromebooks use it to share the
     user's Download folder with their unprivileged containers in their
     Linux subsystem.

   - It is possible to share files between containers with
     non-overlapping idmappings.

   - Filesystem that lack a proper concept of ownership such as fat can
     use idmapped mounts to implement discretionary access (DAC)
     permission checking.

   - They allow users to efficiently changing ownership on a per-mount
     basis without having to (recursively) chown(2) all files. In
     contrast to chown (2) changing ownership of large sets of files is
     instantenous with idmapped mounts. This is especially useful when
     ownership of a whole root filesystem of a virtual machine or
     container is changed. With idmapped mounts a single syscall
     mount_setattr syscall will be sufficient to change the ownership of
     all files.

   - Idmapped mounts always take the current ownership into account as
     idmappings specify what a given uid or gid is supposed to be mapped
     to. This contrasts with the chown(2) syscall which cannot by itself
     take the current ownership of the files it changes into account. It
     simply changes the ownership to the specified uid and gid. This is
     especially problematic when recursively chown(2)ing a large set of
     files which is commong with the aforementioned portable home
     directory and container and vm scenario.

   - Idmapped mounts allow to change ownership locally, restricting it
     to specific mounts, and temporarily as the ownership changes only
     apply as long as the mount exists.

  Several userspace projects have either already put up patches and
  pull-requests for this feature or will do so should you decide to pull
  this:

   - systemd: In a wide variety of scenarios but especially right away
     in their implementation of portable home directories.

         https://systemd.io/HOME_DIRECTORY/

   - container runtimes: containerd, runC, LXD:To share data between
     host and unprivileged containers, unprivileged and privileged
     containers, etc. The pull request for idmapped mounts support in
     containerd, the default Kubernetes runtime is already up for quite
     a while now: https://github.com/containerd/containerd/pull/4734

   - The virtio-fs developers and several users have expressed interest
     in using this feature with virtual machines once virtio-fs is
     ported.

   - ChromeOS: Sharing host-directories with unprivileged containers.

  I've tightly synced with all those projects and all of those listed
  here have also expressed their need/desire for this feature on the
  mailing list. For more info on how people use this there's a bunch of
  talks about this too. Here's just two recent ones:

      https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdf
      https://fosdem.org/2021/schedule/event/containers_idmap/

  This comes with an extensive xfstests suite covering both ext4 and
  xfs:

      https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts

  It covers truncation, creation, opening, xattrs, vfscaps, setid
  execution, setgid inheritance and more both with idmapped and
  non-idmapped mounts. It already helped to discover an unrelated xfs
  setgid inheritance bug which has since been fixed in mainline. It will
  be sent for inclusion with the xfstests project should you decide to
  merge this.

  In order to support per-mount idmappings vfsmounts are marked with
  user namespaces. The idmapping of the user namespace will be used to
  map the ids of vfs objects when they are accessed through that mount.
  By default all vfsmounts are marked with the initial user namespace.
  The initial user namespace is used to indicate that a mount is not
  idmapped. All operations behave as before and this is verified in the
  testsuite.

  Based on prior discussions we want to attach the whole user namespace
  and not just a dedicated idmapping struct. This allows us to reuse all
  the helpers that already exist for dealing with idmappings instead of
  introducing a whole new range of helpers. In addition, if we decide in
  the future that we are confident enough to enable unprivileged users
  to setup idmapped mounts the permission checking can take into account
  whether the caller is privileged in the user namespace the mount is
  currently marked with.

  The user namespace the mount will be marked with can be specified by
  passing a file descriptor refering to the user namespace as an
  argument to the new mount_setattr() syscall together with the new
  MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern
  of extensibility.

  The following conditions must be met in order to create an idmapped
  mount:

   - The caller must currently have the CAP_SYS_ADMIN capability in the
     user namespace the underlying filesystem has been mounted in.

   - The underlying filesystem must support idmapped mounts.

   - The mount must not already be idmapped. This also implies that the
     idmapping of a mount cannot be altered once it has been idmapped.

   - The mount must be a detached/anonymous mount, i.e. it must have
     been created by calling open_tree() with the OPEN_TREE_CLONE flag
     and it must not already have been visible in the filesystem.

  The last two points guarantee easier semantics for userspace and the
  kernel and make the implementation significantly simpler.

  By default vfsmounts are marked with the initial user namespace and no
  behavioral or performance changes are observed.

  The manpage with a detailed description can be found here:

      1d7b902e28

  In order to support idmapped mounts, filesystems need to be changed
  and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The
  patches to convert individual filesystem are not very large or
  complicated overall as can be seen from the included fat, ext4, and
  xfs ports. Patches for other filesystems are actively worked on and
  will be sent out separately. The xfstestsuite can be used to verify
  that port has been done correctly.

  The mount_setattr() syscall is motivated independent of the idmapped
  mounts patches and it's been around since July 2019. One of the most
  valuable features of the new mount api is the ability to perform
  mounts based on file descriptors only.

  Together with the lookup restrictions available in the openat2()
  RESOLVE_* flag namespace which we added in v5.6 this is the first time
  we are close to hardened and race-free (e.g. symlinks) mounting and
  path resolution.

  While userspace has started porting to the new mount api to mount
  proper filesystems and create new bind-mounts it is currently not
  possible to change mount options of an already existing bind mount in
  the new mount api since the mount_setattr() syscall is missing.

  With the addition of the mount_setattr() syscall we remove this last
  restriction and userspace can now fully port to the new mount api,
  covering every use-case the old mount api could. We also add the
  crucial ability to recursively change mount options for a whole mount
  tree, both removing and adding mount options at the same time. This
  syscall has been requested multiple times by various people and
  projects.

  There is a simple tool available at

      https://github.com/brauner/mount-idmapped

  that allows to create idmapped mounts so people can play with this
  patch series. I'll add support for the regular mount binary should you
  decide to pull this in the following weeks:

  Here's an example to a simple idmapped mount of another user's home
  directory:

	u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt

	u1001@f2-vm:/$ ls -al /home/ubuntu/
	total 28
	drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 .
	drwxr-xr-x 4 root   root   4096 Oct 28 04:00 ..
	-rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history
	-rw-r--r-- 1 ubuntu ubuntu  220 Feb 25  2020 .bash_logout
	-rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25  2020 .bashrc
	-rw-r--r-- 1 ubuntu ubuntu  807 Feb 25  2020 .profile
	-rw-r--r-- 1 ubuntu ubuntu    0 Oct 16 16:11 .sudo_as_admin_successful
	-rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo

	u1001@f2-vm:/$ ls -al /mnt/
	total 28
	drwxr-xr-x  2 u1001 u1001 4096 Oct 28 22:07 .
	drwxr-xr-x 29 root  root  4096 Oct 28 22:01 ..
	-rw-------  1 u1001 u1001 3154 Oct 28 22:12 .bash_history
	-rw-r--r--  1 u1001 u1001  220 Feb 25  2020 .bash_logout
	-rw-r--r--  1 u1001 u1001 3771 Feb 25  2020 .bashrc
	-rw-r--r--  1 u1001 u1001  807 Feb 25  2020 .profile
	-rw-r--r--  1 u1001 u1001    0 Oct 16 16:11 .sudo_as_admin_successful
	-rw-------  1 u1001 u1001 1144 Oct 28 00:43 .viminfo

	u1001@f2-vm:/$ touch /mnt/my-file

	u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file

	u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file

	u1001@f2-vm:/$ ls -al /mnt/my-file
	-rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file

	u1001@f2-vm:/$ ls -al /home/ubuntu/my-file
	-rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file

	u1001@f2-vm:/$ getfacl /mnt/my-file
	getfacl: Removing leading '/' from absolute path names
	# file: mnt/my-file
	# owner: u1001
	# group: u1001
	user::rw-
	user:u1001:rwx
	group::rw-
	mask::rwx
	other::r--

	u1001@f2-vm:/$ getfacl /home/ubuntu/my-file
	getfacl: Removing leading '/' from absolute path names
	# file: home/ubuntu/my-file
	# owner: ubuntu
	# group: ubuntu
	user::rw-
	user:ubuntu:rwx
	group::rw-
	mask::rwx
	other::r--"

* tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits)
  xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl
  xfs: support idmapped mounts
  ext4: support idmapped mounts
  fat: handle idmapped mounts
  tests: add mount_setattr() selftests
  fs: introduce MOUNT_ATTR_IDMAP
  fs: add mount_setattr()
  fs: add attr_flags_to_mnt_flags helper
  fs: split out functions to hold writers
  namespace: only take read lock in do_reconfigure_mnt()
  mount: make {lock,unlock}_mount_hash() static
  namespace: take lock_mount_hash() directly when changing flags
  nfs: do not export idmapped mounts
  overlayfs: do not mount on top of idmapped mounts
  ecryptfs: do not mount on top of idmapped mounts
  ima: handle idmapped mounts
  apparmor: handle idmapped mounts
  fs: make helpers idmap mount aware
  exec: handle idmapped mounts
  would_dump: handle idmapped mounts
  ...
2021-02-23 13:39:45 -08:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Process version 2 NFS requests.
*
* Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/namei.h>
#include "cache.h"
#include "xdr.h"
#include "vfs.h"
#define NFSDDBG_FACILITY NFSDDBG_PROC
static __be32
nfsd_proc_null(struct svc_rqst *rqstp)
{
return rpc_success;
}
/*
* Get a file's attributes
* N.B. After this call resp->fh needs an fh_put
*/
static __be32
nfsd_proc_getattr(struct svc_rqst *rqstp)
{
struct nfsd_fhandle *argp = rqstp->rq_argp;
struct nfsd_attrstat *resp = rqstp->rq_resp;
dprintk("nfsd: GETATTR %s\n", SVCFH_fmt(&argp->fh));
fh_copy(&resp->fh, &argp->fh);
resp->status = fh_verify(rqstp, &resp->fh, 0,
NFSD_MAY_NOP | NFSD_MAY_BYPASS_GSS_ON_ROOT);
if (resp->status != nfs_ok)
goto out;
resp->status = fh_getattr(&resp->fh, &resp->stat);
out:
return rpc_success;
}
/*
* Set a file's attributes
* N.B. After this call resp->fh needs an fh_put
*/
static __be32
nfsd_proc_setattr(struct svc_rqst *rqstp)
{
struct nfsd_sattrargs *argp = rqstp->rq_argp;
struct nfsd_attrstat *resp = rqstp->rq_resp;
struct iattr *iap = &argp->attrs;
struct svc_fh *fhp;
dprintk("nfsd: SETATTR %s, valid=%x, size=%ld\n",
SVCFH_fmt(&argp->fh),
argp->attrs.ia_valid, (long) argp->attrs.ia_size);
fhp = fh_copy(&resp->fh, &argp->fh);
/*
* NFSv2 does not differentiate between "set-[ac]time-to-now"
* which only requires access, and "set-[ac]time-to-X" which
* requires ownership.
* So if it looks like it might be "set both to the same time which
* is close to now", and if setattr_prepare fails, then we
* convert to "set to now" instead of "set to explicit time"
*
* We only call setattr_prepare as the last test as technically
* it is not an interface that we should be using.
*/
#define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET)
#define MAX_TOUCH_TIME_ERROR (30*60)
if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET &&
iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) {
/*
* Looks probable.
*
* Now just make sure time is in the right ballpark.
* Solaris, at least, doesn't seem to care what the time
* request is. We require it be within 30 minutes of now.
*/
time64_t delta = iap->ia_atime.tv_sec - ktime_get_real_seconds();
resp->status = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
if (resp->status != nfs_ok)
goto out;
if (delta < 0)
delta = -delta;
if (delta < MAX_TOUCH_TIME_ERROR &&
setattr_prepare(&init_user_ns, fhp->fh_dentry, iap) != 0) {
/*
* Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME.
* This will cause notify_change to set these times
* to "now"
*/
iap->ia_valid &= ~BOTH_TIME_SET;
}
}
resp->status = nfsd_setattr(rqstp, fhp, iap, 0, (time64_t)0);
if (resp->status != nfs_ok)
goto out;
resp->status = fh_getattr(&resp->fh, &resp->stat);
out:
return rpc_success;
}
/* Obsolete, replaced by MNTPROC_MNT. */
static __be32
nfsd_proc_root(struct svc_rqst *rqstp)
{
return rpc_success;
}
/*
* Look up a path name component
* Note: the dentry in the resp->fh may be negative if the file
* doesn't exist yet.
* N.B. After this call resp->fh needs an fh_put
*/
static __be32
nfsd_proc_lookup(struct svc_rqst *rqstp)
{
struct nfsd_diropargs *argp = rqstp->rq_argp;
struct nfsd_diropres *resp = rqstp->rq_resp;
dprintk("nfsd: LOOKUP %s %.*s\n",
SVCFH_fmt(&argp->fh), argp->len, argp->name);
fh_init(&resp->fh, NFS_FHSIZE);
resp->status = nfsd_lookup(rqstp, &argp->fh, argp->name, argp->len,
&resp->fh);
fh_put(&argp->fh);
if (resp->status != nfs_ok)
goto out;
resp->status = fh_getattr(&resp->fh, &resp->stat);
out:
return rpc_success;
}
/*
* Read a symlink.
*/
static __be32
nfsd_proc_readlink(struct svc_rqst *rqstp)
{
struct nfsd_fhandle *argp = rqstp->rq_argp;
struct nfsd_readlinkres *resp = rqstp->rq_resp;
char *buffer = page_address(*(rqstp->rq_next_page++));
dprintk("nfsd: READLINK %s\n", SVCFH_fmt(&argp->fh));
/* Read the symlink. */
resp->len = NFS_MAXPATHLEN;
resp->status = nfsd_readlink(rqstp, &argp->fh, buffer, &resp->len);
fh_put(&argp->fh);
return rpc_success;
}
/*
* Read a portion of a file.
* N.B. After this call resp->fh needs an fh_put
*/
static __be32
nfsd_proc_read(struct svc_rqst *rqstp)
{
struct nfsd_readargs *argp = rqstp->rq_argp;
struct nfsd_readres *resp = rqstp->rq_resp;
unsigned int len;
u32 eof;
int v;
dprintk("nfsd: READ %s %d bytes at %d\n",
SVCFH_fmt(&argp->fh),
argp->count, argp->offset);
argp->count = min_t(u32, argp->count, NFSSVC_MAXBLKSIZE_V2);
v = 0;
len = argp->count;
while (len > 0) {
struct page *page = *(rqstp->rq_next_page++);
rqstp->rq_vec[v].iov_base = page_address(page);
rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE);
len -= rqstp->rq_vec[v].iov_len;
v++;
}
/* Obtain buffer pointer for payload. 19 is 1 word for
* status, 17 words for fattr, and 1 word for the byte count.
*/
svc_reserve_auth(rqstp, (19<<2) + argp->count + 4);
resp->count = argp->count;
fh_copy(&resp->fh, &argp->fh);
resp->status = nfsd_read(rqstp, &resp->fh, argp->offset,
rqstp->rq_vec, v, &resp->count, &eof);
if (resp->status == nfs_ok)
resp->status = fh_getattr(&resp->fh, &resp->stat);
else if (resp->status == nfserr_jukebox)
return rpc_drop_reply;
return rpc_success;
}
/* Reserved */
static __be32
nfsd_proc_writecache(struct svc_rqst *rqstp)
{
return rpc_success;
}
/*
* Write data to a file
* N.B. After this call resp->fh needs an fh_put
*/
static __be32
nfsd_proc_write(struct svc_rqst *rqstp)
{
struct nfsd_writeargs *argp = rqstp->rq_argp;
struct nfsd_attrstat *resp = rqstp->rq_resp;
unsigned long cnt = argp->len;
unsigned int nvecs;
dprintk("nfsd: WRITE %s %d bytes at %d\n",
SVCFH_fmt(&argp->fh),
argp->len, argp->offset);
nvecs = svc_fill_write_vector(rqstp, rqstp->rq_arg.pages,
&argp->first, cnt);
if (!nvecs) {
resp->status = nfserr_io;
goto out;
}
resp->status = nfsd_write(rqstp, fh_copy(&resp->fh, &argp->fh),
argp->offset, rqstp->rq_vec, nvecs,
&cnt, NFS_DATA_SYNC, NULL);
if (resp->status == nfs_ok)
resp->status = fh_getattr(&resp->fh, &resp->stat);
else if (resp->status == nfserr_jukebox)
return rpc_drop_reply;
out:
return rpc_success;
}
/*
* CREATE processing is complicated. The keyword here is `overloaded.'
* The parent directory is kept locked between the check for existence
* and the actual create() call in compliance with VFS protocols.
* N.B. After this call _both_ argp->fh and resp->fh need an fh_put
*/
static __be32
nfsd_proc_create(struct svc_rqst *rqstp)
{
struct nfsd_createargs *argp = rqstp->rq_argp;
struct nfsd_diropres *resp = rqstp->rq_resp;
svc_fh *dirfhp = &argp->fh;
svc_fh *newfhp = &resp->fh;
struct iattr *attr = &argp->attrs;
struct inode *inode;
struct dentry *dchild;
int type, mode;
int hosterr;
dev_t rdev = 0, wanted = new_decode_dev(attr->ia_size);
dprintk("nfsd: CREATE %s %.*s\n",
SVCFH_fmt(dirfhp), argp->len, argp->name);
/* First verify the parent file handle */
resp->status = fh_verify(rqstp, dirfhp, S_IFDIR, NFSD_MAY_EXEC);
if (resp->status != nfs_ok)
goto done; /* must fh_put dirfhp even on error */
/* Check for NFSD_MAY_WRITE in nfsd_create if necessary */
resp->status = nfserr_exist;
if (isdotent(argp->name, argp->len))
goto done;
hosterr = fh_want_write(dirfhp);
if (hosterr) {
resp->status = nfserrno(hosterr);
goto done;
}
fh_lock_nested(dirfhp, I_MUTEX_PARENT);
dchild = lookup_one_len(argp->name, dirfhp->fh_dentry, argp->len);
if (IS_ERR(dchild)) {
resp->status = nfserrno(PTR_ERR(dchild));
goto out_unlock;
}
fh_init(newfhp, NFS_FHSIZE);
resp->status = fh_compose(newfhp, dirfhp->fh_export, dchild, dirfhp);
if (!resp->status && d_really_is_negative(dchild))
resp->status = nfserr_noent;
dput(dchild);
if (resp->status) {
if (resp->status != nfserr_noent)
goto out_unlock;
/*
* If the new file handle wasn't verified, we can't tell
* whether the file exists or not. Time to bail ...
*/
resp->status = nfserr_acces;
if (!newfhp->fh_dentry) {
printk(KERN_WARNING
"nfsd_proc_create: file handle not verified\n");
goto out_unlock;
}
}
inode = d_inode(newfhp->fh_dentry);
/* Unfudge the mode bits */
if (attr->ia_valid & ATTR_MODE) {
type = attr->ia_mode & S_IFMT;
mode = attr->ia_mode & ~S_IFMT;
if (!type) {
/* no type, so if target exists, assume same as that,
* else assume a file */
if (inode) {
type = inode->i_mode & S_IFMT;
switch(type) {
case S_IFCHR:
case S_IFBLK:
/* reserve rdev for later checking */
rdev = inode->i_rdev;
attr->ia_valid |= ATTR_SIZE;
fallthrough;
case S_IFIFO:
/* this is probably a permission check..
* at least IRIX implements perm checking on
* echo thing > device-special-file-or-pipe
* by doing a CREATE with type==0
*/
resp->status = nfsd_permission(rqstp,
newfhp->fh_export,
newfhp->fh_dentry,
NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS);
if (resp->status && resp->status != nfserr_rofs)
goto out_unlock;
}
} else
type = S_IFREG;
}
} else if (inode) {
type = inode->i_mode & S_IFMT;
mode = inode->i_mode & ~S_IFMT;
} else {
type = S_IFREG;
mode = 0; /* ??? */
}
attr->ia_valid |= ATTR_MODE;
attr->ia_mode = mode;
/* Special treatment for non-regular files according to the
* gospel of sun micro
*/
if (type != S_IFREG) {
if (type != S_IFBLK && type != S_IFCHR) {
rdev = 0;
} else if (type == S_IFCHR && !(attr->ia_valid & ATTR_SIZE)) {
/* If you think you've seen the worst, grok this. */
type = S_IFIFO;
} else {
/* Okay, char or block special */
if (!rdev)
rdev = wanted;
}
/* we've used the SIZE information, so discard it */
attr->ia_valid &= ~ATTR_SIZE;
/* Make sure the type and device matches */
resp->status = nfserr_exist;
if (inode && type != (inode->i_mode & S_IFMT))
goto out_unlock;
}
resp->status = nfs_ok;
if (!inode) {
/* File doesn't exist. Create it and set attrs */
resp->status = nfsd_create_locked(rqstp, dirfhp, argp->name,
argp->len, attr, type, rdev,
newfhp);
} else if (type == S_IFREG) {
dprintk("nfsd: existing %s, valid=%x, size=%ld\n",
argp->name, attr->ia_valid, (long) attr->ia_size);
/* File already exists. We ignore all attributes except
* size, so that creat() behaves exactly like
* open(..., O_CREAT|O_TRUNC|O_WRONLY).
*/
attr->ia_valid &= ATTR_SIZE;
if (attr->ia_valid)
resp->status = nfsd_setattr(rqstp, newfhp, attr, 0,
(time64_t)0);
}
out_unlock:
/* We don't really need to unlock, as fh_put does it. */
fh_unlock(dirfhp);
fh_drop_write(dirfhp);
done:
fh_put(dirfhp);
if (resp->status != nfs_ok)
goto out;
resp->status = fh_getattr(&resp->fh, &resp->stat);
out:
return rpc_success;
}
static __be32
nfsd_proc_remove(struct svc_rqst *rqstp)
{
struct nfsd_diropargs *argp = rqstp->rq_argp;
struct nfsd_stat *resp = rqstp->rq_resp;
dprintk("nfsd: REMOVE %s %.*s\n", SVCFH_fmt(&argp->fh),
argp->len, argp->name);
/* Unlink. -SIFDIR means file must not be a directory */
resp->status = nfsd_unlink(rqstp, &argp->fh, -S_IFDIR,
argp->name, argp->len);
fh_put(&argp->fh);
return rpc_success;
}
static __be32
nfsd_proc_rename(struct svc_rqst *rqstp)
{
struct nfsd_renameargs *argp = rqstp->rq_argp;
struct nfsd_stat *resp = rqstp->rq_resp;
dprintk("nfsd: RENAME %s %.*s -> \n",
SVCFH_fmt(&argp->ffh), argp->flen, argp->fname);
dprintk("nfsd: -> %s %.*s\n",
SVCFH_fmt(&argp->tfh), argp->tlen, argp->tname);
resp->status = nfsd_rename(rqstp, &argp->ffh, argp->fname, argp->flen,
&argp->tfh, argp->tname, argp->tlen);
fh_put(&argp->ffh);
fh_put(&argp->tfh);
return rpc_success;
}
static __be32
nfsd_proc_link(struct svc_rqst *rqstp)
{
struct nfsd_linkargs *argp = rqstp->rq_argp;
struct nfsd_stat *resp = rqstp->rq_resp;
dprintk("nfsd: LINK %s ->\n",
SVCFH_fmt(&argp->ffh));
dprintk("nfsd: %s %.*s\n",
SVCFH_fmt(&argp->tfh),
argp->tlen,
argp->tname);
resp->status = nfsd_link(rqstp, &argp->tfh, argp->tname, argp->tlen,
&argp->ffh);
fh_put(&argp->ffh);
fh_put(&argp->tfh);
return rpc_success;
}
static __be32
nfsd_proc_symlink(struct svc_rqst *rqstp)
{
struct nfsd_symlinkargs *argp = rqstp->rq_argp;
struct nfsd_stat *resp = rqstp->rq_resp;
struct svc_fh newfh;
if (argp->tlen > NFS_MAXPATHLEN) {
resp->status = nfserr_nametoolong;
goto out;
}
argp->tname = svc_fill_symlink_pathname(rqstp, &argp->first,
page_address(rqstp->rq_arg.pages[0]),
argp->tlen);
if (IS_ERR(argp->tname)) {
resp->status = nfserrno(PTR_ERR(argp->tname));
goto out;
}
dprintk("nfsd: SYMLINK %s %.*s -> %.*s\n",
SVCFH_fmt(&argp->ffh), argp->flen, argp->fname,
argp->tlen, argp->tname);
fh_init(&newfh, NFS_FHSIZE);
resp->status = nfsd_symlink(rqstp, &argp->ffh, argp->fname, argp->flen,
argp->tname, &newfh);
kfree(argp->tname);
fh_put(&argp->ffh);
fh_put(&newfh);
out:
return rpc_success;
}
/*
* Make directory. This operation is not idempotent.
* N.B. After this call resp->fh needs an fh_put
*/
static __be32
nfsd_proc_mkdir(struct svc_rqst *rqstp)
{
struct nfsd_createargs *argp = rqstp->rq_argp;
struct nfsd_diropres *resp = rqstp->rq_resp;
dprintk("nfsd: MKDIR %s %.*s\n", SVCFH_fmt(&argp->fh), argp->len, argp->name);
if (resp->fh.fh_dentry) {
printk(KERN_WARNING
"nfsd_proc_mkdir: response already verified??\n");
}
argp->attrs.ia_valid &= ~ATTR_SIZE;
fh_init(&resp->fh, NFS_FHSIZE);
resp->status = nfsd_create(rqstp, &argp->fh, argp->name, argp->len,
&argp->attrs, S_IFDIR, 0, &resp->fh);
fh_put(&argp->fh);
if (resp->status != nfs_ok)
goto out;
resp->status = fh_getattr(&resp->fh, &resp->stat);
out:
return rpc_success;
}
/*
* Remove a directory
*/
static __be32
nfsd_proc_rmdir(struct svc_rqst *rqstp)
{
struct nfsd_diropargs *argp = rqstp->rq_argp;
struct nfsd_stat *resp = rqstp->rq_resp;
dprintk("nfsd: RMDIR %s %.*s\n", SVCFH_fmt(&argp->fh), argp->len, argp->name);
resp->status = nfsd_unlink(rqstp, &argp->fh, S_IFDIR,
argp->name, argp->len);
fh_put(&argp->fh);
return rpc_success;
}
static void nfsd_init_dirlist_pages(struct svc_rqst *rqstp,
struct nfsd_readdirres *resp,
int count)
{
count = min_t(u32, count, PAGE_SIZE);
/* Convert byte count to number of words (i.e. >> 2),
* and reserve room for the NULL ptr & eof flag (-2 words) */
resp->buflen = (count >> 2) - 2;
resp->buffer = page_address(*rqstp->rq_next_page);
rqstp->rq_next_page++;
}
/*
* Read a portion of a directory.
*/
static __be32
nfsd_proc_readdir(struct svc_rqst *rqstp)
{
struct nfsd_readdirargs *argp = rqstp->rq_argp;
struct nfsd_readdirres *resp = rqstp->rq_resp;
loff_t offset;
__be32 *buffer;
dprintk("nfsd: READDIR %s %d bytes at %d\n",
SVCFH_fmt(&argp->fh),
argp->count, argp->cookie);
nfsd_init_dirlist_pages(rqstp, resp, argp->count);
buffer = resp->buffer;
resp->offset = NULL;
resp->common.err = nfs_ok;
/* Read directory and encode entries on the fly */
offset = argp->cookie;
resp->status = nfsd_readdir(rqstp, &argp->fh, &offset,
&resp->common, nfssvc_encode_entry);
resp->count = resp->buffer - buffer;
if (resp->offset)
*resp->offset = htonl(offset);
fh_put(&argp->fh);
return rpc_success;
}
/*
* Get file system info
*/
static __be32
nfsd_proc_statfs(struct svc_rqst *rqstp)
{
struct nfsd_fhandle *argp = rqstp->rq_argp;
struct nfsd_statfsres *resp = rqstp->rq_resp;
dprintk("nfsd: STATFS %s\n", SVCFH_fmt(&argp->fh));
resp->status = nfsd_statfs(rqstp, &argp->fh, &resp->stats,
NFSD_MAY_BYPASS_GSS_ON_ROOT);
fh_put(&argp->fh);
return rpc_success;
}
/*
* NFSv2 Server procedures.
* Only the results of non-idempotent operations are cached.
*/
#define ST 1 /* status */
#define FH 8 /* filehandle */
#define AT 18 /* attributes */
static const struct svc_procedure nfsd_procedures2[18] = {
[NFSPROC_NULL] = {
.pc_func = nfsd_proc_null,
.pc_decode = nfssvc_decode_voidarg,
.pc_encode = nfssvc_encode_voidres,
.pc_argsize = sizeof(struct nfsd_voidargs),
.pc_ressize = sizeof(struct nfsd_voidres),
.pc_cachetype = RC_NOCACHE,
.pc_xdrressize = 0,
.pc_name = "NULL",
},
[NFSPROC_GETATTR] = {
.pc_func = nfsd_proc_getattr,
.pc_decode = nfssvc_decode_fhandleargs,
.pc_encode = nfssvc_encode_attrstat,
.pc_release = nfssvc_release_attrstat,
.pc_argsize = sizeof(struct nfsd_fhandle),
.pc_ressize = sizeof(struct nfsd_attrstat),
.pc_cachetype = RC_NOCACHE,
.pc_xdrressize = ST+AT,
.pc_name = "GETATTR",
},
[NFSPROC_SETATTR] = {
.pc_func = nfsd_proc_setattr,
.pc_decode = nfssvc_decode_sattrargs,
.pc_encode = nfssvc_encode_attrstat,
.pc_release = nfssvc_release_attrstat,
.pc_argsize = sizeof(struct nfsd_sattrargs),
.pc_ressize = sizeof(struct nfsd_attrstat),
.pc_cachetype = RC_REPLBUFF,
.pc_xdrressize = ST+AT,
.pc_name = "SETATTR",
},
[NFSPROC_ROOT] = {
.pc_func = nfsd_proc_root,
.pc_decode = nfssvc_decode_voidarg,
.pc_encode = nfssvc_encode_voidres,
.pc_argsize = sizeof(struct nfsd_voidargs),
.pc_ressize = sizeof(struct nfsd_voidres),
.pc_cachetype = RC_NOCACHE,
.pc_xdrressize = 0,
.pc_name = "ROOT",
},
[NFSPROC_LOOKUP] = {
.pc_func = nfsd_proc_lookup,
.pc_decode = nfssvc_decode_diropargs,
.pc_encode = nfssvc_encode_diropres,
.pc_release = nfssvc_release_diropres,
.pc_argsize = sizeof(struct nfsd_diropargs),
.pc_ressize = sizeof(struct nfsd_diropres),
.pc_cachetype = RC_NOCACHE,
.pc_xdrressize = ST+FH+AT,
.pc_name = "LOOKUP",
},
[NFSPROC_READLINK] = {
.pc_func = nfsd_proc_readlink,
.pc_decode = nfssvc_decode_fhandleargs,
.pc_encode = nfssvc_encode_readlinkres,
.pc_argsize = sizeof(struct nfsd_fhandle),
.pc_ressize = sizeof(struct nfsd_readlinkres),
.pc_cachetype = RC_NOCACHE,
.pc_xdrressize = ST+1+NFS_MAXPATHLEN/4,
.pc_name = "READLINK",
},
[NFSPROC_READ] = {
.pc_func = nfsd_proc_read,
.pc_decode = nfssvc_decode_readargs,
.pc_encode = nfssvc_encode_readres,
.pc_release = nfssvc_release_readres,
.pc_argsize = sizeof(struct nfsd_readargs),
.pc_ressize = sizeof(struct nfsd_readres),
.pc_cachetype = RC_NOCACHE,
.pc_xdrressize = ST+AT+1+NFSSVC_MAXBLKSIZE_V2/4,
.pc_name = "READ",
},
[NFSPROC_WRITECACHE] = {
.pc_func = nfsd_proc_writecache,
.pc_decode = nfssvc_decode_voidarg,
.pc_encode = nfssvc_encode_voidres,
.pc_argsize = sizeof(struct nfsd_voidargs),
.pc_ressize = sizeof(struct nfsd_voidres),
.pc_cachetype = RC_NOCACHE,
.pc_xdrressize = 0,
.pc_name = "WRITECACHE",
},
[NFSPROC_WRITE] = {
.pc_func = nfsd_proc_write,
.pc_decode = nfssvc_decode_writeargs,
.pc_encode = nfssvc_encode_attrstat,
.pc_release = nfssvc_release_attrstat,
.pc_argsize = sizeof(struct nfsd_writeargs),
.pc_ressize = sizeof(struct nfsd_attrstat),
.pc_cachetype = RC_REPLBUFF,
.pc_xdrressize = ST+AT,
.pc_name = "WRITE",
},
[NFSPROC_CREATE] = {
.pc_func = nfsd_proc_create,
.pc_decode = nfssvc_decode_createargs,
.pc_encode = nfssvc_encode_diropres,
.pc_release = nfssvc_release_diropres,
.pc_argsize = sizeof(struct nfsd_createargs),
.pc_ressize = sizeof(struct nfsd_diropres),
.pc_cachetype = RC_REPLBUFF,
.pc_xdrressize = ST+FH+AT,
.pc_name = "CREATE",
},
[NFSPROC_REMOVE] = {
.pc_func = nfsd_proc_remove,
.pc_decode = nfssvc_decode_diropargs,
.pc_encode = nfssvc_encode_stat,
.pc_argsize = sizeof(struct nfsd_diropargs),
.pc_ressize = sizeof(struct nfsd_stat),
.pc_cachetype = RC_REPLSTAT,
.pc_xdrressize = ST,
.pc_name = "REMOVE",
},
[NFSPROC_RENAME] = {
.pc_func = nfsd_proc_rename,
.pc_decode = nfssvc_decode_renameargs,
.pc_encode = nfssvc_encode_stat,
.pc_argsize = sizeof(struct nfsd_renameargs),
.pc_ressize = sizeof(struct nfsd_stat),
.pc_cachetype = RC_REPLSTAT,
.pc_xdrressize = ST,
.pc_name = "RENAME",
},
[NFSPROC_LINK] = {
.pc_func = nfsd_proc_link,
.pc_decode = nfssvc_decode_linkargs,
.pc_encode = nfssvc_encode_stat,
.pc_argsize = sizeof(struct nfsd_linkargs),
.pc_ressize = sizeof(struct nfsd_stat),
.pc_cachetype = RC_REPLSTAT,
.pc_xdrressize = ST,
.pc_name = "LINK",
},
[NFSPROC_SYMLINK] = {
.pc_func = nfsd_proc_symlink,
.pc_decode = nfssvc_decode_symlinkargs,
.pc_encode = nfssvc_encode_stat,
.pc_argsize = sizeof(struct nfsd_symlinkargs),
.pc_ressize = sizeof(struct nfsd_stat),
.pc_cachetype = RC_REPLSTAT,
.pc_xdrressize = ST,
.pc_name = "SYMLINK",
},
[NFSPROC_MKDIR] = {
.pc_func = nfsd_proc_mkdir,
.pc_decode = nfssvc_decode_createargs,
.pc_encode = nfssvc_encode_diropres,
.pc_release = nfssvc_release_diropres,
.pc_argsize = sizeof(struct nfsd_createargs),
.pc_ressize = sizeof(struct nfsd_diropres),
.pc_cachetype = RC_REPLBUFF,
.pc_xdrressize = ST+FH+AT,
.pc_name = "MKDIR",
},
[NFSPROC_RMDIR] = {
.pc_func = nfsd_proc_rmdir,
.pc_decode = nfssvc_decode_diropargs,
.pc_encode = nfssvc_encode_stat,
.pc_argsize = sizeof(struct nfsd_diropargs),
.pc_ressize = sizeof(struct nfsd_stat),
.pc_cachetype = RC_REPLSTAT,
.pc_xdrressize = ST,
.pc_name = "RMDIR",
},
[NFSPROC_READDIR] = {
.pc_func = nfsd_proc_readdir,
.pc_decode = nfssvc_decode_readdirargs,
.pc_encode = nfssvc_encode_readdirres,
.pc_argsize = sizeof(struct nfsd_readdirargs),
.pc_ressize = sizeof(struct nfsd_readdirres),
.pc_cachetype = RC_NOCACHE,
.pc_name = "READDIR",
},
[NFSPROC_STATFS] = {
.pc_func = nfsd_proc_statfs,
.pc_decode = nfssvc_decode_fhandleargs,
.pc_encode = nfssvc_encode_statfsres,
.pc_argsize = sizeof(struct nfsd_fhandle),
.pc_ressize = sizeof(struct nfsd_statfsres),
.pc_cachetype = RC_NOCACHE,
.pc_xdrressize = ST+5,
.pc_name = "STATFS",
},
};
static unsigned int nfsd_count2[ARRAY_SIZE(nfsd_procedures2)];
const struct svc_version nfsd_version2 = {
.vs_vers = 2,
.vs_nproc = 18,
.vs_proc = nfsd_procedures2,
.vs_count = nfsd_count2,
.vs_dispatch = nfsd_dispatch,
.vs_xdrsize = NFS2_SVC_XDRSIZE,
};
/*
* Map errnos to NFS errnos.
*/
__be32
nfserrno (int errno)
{
static struct {
__be32 nfserr;
int syserr;
} nfs_errtbl[] = {
{ nfs_ok, 0 },
{ nfserr_perm, -EPERM },
{ nfserr_noent, -ENOENT },
{ nfserr_io, -EIO },
{ nfserr_nxio, -ENXIO },
{ nfserr_fbig, -E2BIG },
{ nfserr_acces, -EACCES },
{ nfserr_exist, -EEXIST },
{ nfserr_xdev, -EXDEV },
{ nfserr_mlink, -EMLINK },
{ nfserr_nodev, -ENODEV },
{ nfserr_notdir, -ENOTDIR },
{ nfserr_isdir, -EISDIR },
{ nfserr_inval, -EINVAL },
{ nfserr_fbig, -EFBIG },
{ nfserr_nospc, -ENOSPC },
{ nfserr_rofs, -EROFS },
{ nfserr_mlink, -EMLINK },
{ nfserr_nametoolong, -ENAMETOOLONG },
{ nfserr_notempty, -ENOTEMPTY },
#ifdef EDQUOT
{ nfserr_dquot, -EDQUOT },
#endif
{ nfserr_stale, -ESTALE },
{ nfserr_jukebox, -ETIMEDOUT },
{ nfserr_jukebox, -ERESTARTSYS },
{ nfserr_jukebox, -EAGAIN },
{ nfserr_jukebox, -EWOULDBLOCK },
{ nfserr_jukebox, -ENOMEM },
{ nfserr_io, -ETXTBSY },
{ nfserr_notsupp, -EOPNOTSUPP },
{ nfserr_toosmall, -ETOOSMALL },
{ nfserr_serverfault, -ESERVERFAULT },
{ nfserr_serverfault, -ENFILE },
{ nfserr_io, -EUCLEAN },
{ nfserr_perm, -ENOKEY },
};
int i;
for (i = 0; i < ARRAY_SIZE(nfs_errtbl); i++) {
if (nfs_errtbl[i].syserr == errno)
return nfs_errtbl[i].nfserr;
}
WARN_ONCE(1, "nfsd: non-standard errno: %d\n", errno);
return nfserr_io;
}
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