2291 строка
55 KiB
C
2291 строка
55 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* File operations used by nfsd. Some of these have been ripped from
|
|
* other parts of the kernel because they weren't exported, others
|
|
* are partial duplicates with added or changed functionality.
|
|
*
|
|
* Note that several functions dget() the dentry upon which they want
|
|
* to act, most notably those that create directory entries. Response
|
|
* dentry's are dput()'d if necessary in the release callback.
|
|
* So if you notice code paths that apparently fail to dput() the
|
|
* dentry, don't worry--they have been taken care of.
|
|
*
|
|
* Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de>
|
|
* Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp>
|
|
*/
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/file.h>
|
|
#include <linux/splice.h>
|
|
#include <linux/falloc.h>
|
|
#include <linux/fcntl.h>
|
|
#include <linux/namei.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/fsnotify.h>
|
|
#include <linux/posix_acl_xattr.h>
|
|
#include <linux/xattr.h>
|
|
#include <linux/jhash.h>
|
|
#include <linux/ima.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/exportfs.h>
|
|
#include <linux/writeback.h>
|
|
#include <linux/security.h>
|
|
|
|
#include "xdr3.h"
|
|
|
|
#ifdef CONFIG_NFSD_V4
|
|
#include "../internal.h"
|
|
#include "acl.h"
|
|
#include "idmap.h"
|
|
#include "xdr4.h"
|
|
#endif /* CONFIG_NFSD_V4 */
|
|
|
|
#include "nfsd.h"
|
|
#include "vfs.h"
|
|
#include "filecache.h"
|
|
#include "trace.h"
|
|
|
|
#define NFSDDBG_FACILITY NFSDDBG_FILEOP
|
|
|
|
/*
|
|
* Called from nfsd_lookup and encode_dirent. Check if we have crossed
|
|
* a mount point.
|
|
* Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
|
|
* or nfs_ok having possibly changed *dpp and *expp
|
|
*/
|
|
int
|
|
nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
|
|
struct svc_export **expp)
|
|
{
|
|
struct svc_export *exp = *expp, *exp2 = NULL;
|
|
struct dentry *dentry = *dpp;
|
|
struct path path = {.mnt = mntget(exp->ex_path.mnt),
|
|
.dentry = dget(dentry)};
|
|
int err = 0;
|
|
|
|
err = follow_down(&path);
|
|
if (err < 0)
|
|
goto out;
|
|
if (path.mnt == exp->ex_path.mnt && path.dentry == dentry &&
|
|
nfsd_mountpoint(dentry, exp) == 2) {
|
|
/* This is only a mountpoint in some other namespace */
|
|
path_put(&path);
|
|
goto out;
|
|
}
|
|
|
|
exp2 = rqst_exp_get_by_name(rqstp, &path);
|
|
if (IS_ERR(exp2)) {
|
|
err = PTR_ERR(exp2);
|
|
/*
|
|
* We normally allow NFS clients to continue
|
|
* "underneath" a mountpoint that is not exported.
|
|
* The exception is V4ROOT, where no traversal is ever
|
|
* allowed without an explicit export of the new
|
|
* directory.
|
|
*/
|
|
if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT))
|
|
err = 0;
|
|
path_put(&path);
|
|
goto out;
|
|
}
|
|
if (nfsd_v4client(rqstp) ||
|
|
(exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
|
|
/* successfully crossed mount point */
|
|
/*
|
|
* This is subtle: path.dentry is *not* on path.mnt
|
|
* at this point. The only reason we are safe is that
|
|
* original mnt is pinned down by exp, so we should
|
|
* put path *before* putting exp
|
|
*/
|
|
*dpp = path.dentry;
|
|
path.dentry = dentry;
|
|
*expp = exp2;
|
|
exp2 = exp;
|
|
}
|
|
path_put(&path);
|
|
exp_put(exp2);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
static void follow_to_parent(struct path *path)
|
|
{
|
|
struct dentry *dp;
|
|
|
|
while (path->dentry == path->mnt->mnt_root && follow_up(path))
|
|
;
|
|
dp = dget_parent(path->dentry);
|
|
dput(path->dentry);
|
|
path->dentry = dp;
|
|
}
|
|
|
|
static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp)
|
|
{
|
|
struct svc_export *exp2;
|
|
struct path path = {.mnt = mntget((*exp)->ex_path.mnt),
|
|
.dentry = dget(dparent)};
|
|
|
|
follow_to_parent(&path);
|
|
|
|
exp2 = rqst_exp_parent(rqstp, &path);
|
|
if (PTR_ERR(exp2) == -ENOENT) {
|
|
*dentryp = dget(dparent);
|
|
} else if (IS_ERR(exp2)) {
|
|
path_put(&path);
|
|
return PTR_ERR(exp2);
|
|
} else {
|
|
*dentryp = dget(path.dentry);
|
|
exp_put(*exp);
|
|
*exp = exp2;
|
|
}
|
|
path_put(&path);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* For nfsd purposes, we treat V4ROOT exports as though there was an
|
|
* export at *every* directory.
|
|
* We return:
|
|
* '1' if this dentry *must* be an export point,
|
|
* '2' if it might be, if there is really a mount here, and
|
|
* '0' if there is no chance of an export point here.
|
|
*/
|
|
int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp)
|
|
{
|
|
if (!d_inode(dentry))
|
|
return 0;
|
|
if (exp->ex_flags & NFSEXP_V4ROOT)
|
|
return 1;
|
|
if (nfsd4_is_junction(dentry))
|
|
return 1;
|
|
if (d_mountpoint(dentry))
|
|
/*
|
|
* Might only be a mountpoint in a different namespace,
|
|
* but we need to check.
|
|
*/
|
|
return 2;
|
|
return 0;
|
|
}
|
|
|
|
__be32
|
|
nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
|
|
const char *name, unsigned int len,
|
|
struct svc_export **exp_ret, struct dentry **dentry_ret)
|
|
{
|
|
struct svc_export *exp;
|
|
struct dentry *dparent;
|
|
struct dentry *dentry;
|
|
int host_err;
|
|
|
|
dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
|
|
|
|
dparent = fhp->fh_dentry;
|
|
exp = exp_get(fhp->fh_export);
|
|
|
|
/* Lookup the name, but don't follow links */
|
|
if (isdotent(name, len)) {
|
|
if (len==1)
|
|
dentry = dget(dparent);
|
|
else if (dparent != exp->ex_path.dentry)
|
|
dentry = dget_parent(dparent);
|
|
else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp))
|
|
dentry = dget(dparent); /* .. == . just like at / */
|
|
else {
|
|
/* checking mountpoint crossing is very different when stepping up */
|
|
host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry);
|
|
if (host_err)
|
|
goto out_nfserr;
|
|
}
|
|
} else {
|
|
/*
|
|
* In the nfsd4_open() case, this may be held across
|
|
* subsequent open and delegation acquisition which may
|
|
* need to take the child's i_mutex:
|
|
*/
|
|
fh_lock_nested(fhp, I_MUTEX_PARENT);
|
|
dentry = lookup_one_len(name, dparent, len);
|
|
host_err = PTR_ERR(dentry);
|
|
if (IS_ERR(dentry))
|
|
goto out_nfserr;
|
|
if (nfsd_mountpoint(dentry, exp)) {
|
|
/*
|
|
* We don't need the i_mutex after all. It's
|
|
* still possible we could open this (regular
|
|
* files can be mountpoints too), but the
|
|
* i_mutex is just there to prevent renames of
|
|
* something that we might be about to delegate,
|
|
* and a mountpoint won't be renamed:
|
|
*/
|
|
fh_unlock(fhp);
|
|
if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
|
|
dput(dentry);
|
|
goto out_nfserr;
|
|
}
|
|
}
|
|
}
|
|
*dentry_ret = dentry;
|
|
*exp_ret = exp;
|
|
return 0;
|
|
|
|
out_nfserr:
|
|
exp_put(exp);
|
|
return nfserrno(host_err);
|
|
}
|
|
|
|
/*
|
|
* Look up one component of a pathname.
|
|
* N.B. After this call _both_ fhp and resfh need an fh_put
|
|
*
|
|
* If the lookup would cross a mountpoint, and the mounted filesystem
|
|
* is exported to the client with NFSEXP_NOHIDE, then the lookup is
|
|
* accepted as it stands and the mounted directory is
|
|
* returned. Otherwise the covered directory is returned.
|
|
* NOTE: this mountpoint crossing is not supported properly by all
|
|
* clients and is explicitly disallowed for NFSv3
|
|
* NeilBrown <neilb@cse.unsw.edu.au>
|
|
*/
|
|
__be32
|
|
nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
|
|
unsigned int len, struct svc_fh *resfh)
|
|
{
|
|
struct svc_export *exp;
|
|
struct dentry *dentry;
|
|
__be32 err;
|
|
|
|
err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
|
|
if (err)
|
|
return err;
|
|
err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry);
|
|
if (err)
|
|
return err;
|
|
err = check_nfsd_access(exp, rqstp);
|
|
if (err)
|
|
goto out;
|
|
/*
|
|
* Note: we compose the file handle now, but as the
|
|
* dentry may be negative, it may need to be updated.
|
|
*/
|
|
err = fh_compose(resfh, exp, dentry, fhp);
|
|
if (!err && d_really_is_negative(dentry))
|
|
err = nfserr_noent;
|
|
out:
|
|
dput(dentry);
|
|
exp_put(exp);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Commit metadata changes to stable storage.
|
|
*/
|
|
static int
|
|
commit_inode_metadata(struct inode *inode)
|
|
{
|
|
const struct export_operations *export_ops = inode->i_sb->s_export_op;
|
|
|
|
if (export_ops->commit_metadata)
|
|
return export_ops->commit_metadata(inode);
|
|
return sync_inode_metadata(inode, 1);
|
|
}
|
|
|
|
static int
|
|
commit_metadata(struct svc_fh *fhp)
|
|
{
|
|
struct inode *inode = d_inode(fhp->fh_dentry);
|
|
|
|
if (!EX_ISSYNC(fhp->fh_export))
|
|
return 0;
|
|
return commit_inode_metadata(inode);
|
|
}
|
|
|
|
/*
|
|
* Go over the attributes and take care of the small differences between
|
|
* NFS semantics and what Linux expects.
|
|
*/
|
|
static void
|
|
nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap)
|
|
{
|
|
/* sanitize the mode change */
|
|
if (iap->ia_valid & ATTR_MODE) {
|
|
iap->ia_mode &= S_IALLUGO;
|
|
iap->ia_mode |= (inode->i_mode & ~S_IALLUGO);
|
|
}
|
|
|
|
/* Revoke setuid/setgid on chown */
|
|
if (!S_ISDIR(inode->i_mode) &&
|
|
((iap->ia_valid & ATTR_UID) || (iap->ia_valid & ATTR_GID))) {
|
|
iap->ia_valid |= ATTR_KILL_PRIV;
|
|
if (iap->ia_valid & ATTR_MODE) {
|
|
/* we're setting mode too, just clear the s*id bits */
|
|
iap->ia_mode &= ~S_ISUID;
|
|
if (iap->ia_mode & S_IXGRP)
|
|
iap->ia_mode &= ~S_ISGID;
|
|
} else {
|
|
/* set ATTR_KILL_* bits and let VFS handle it */
|
|
iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID);
|
|
}
|
|
}
|
|
}
|
|
|
|
static __be32
|
|
nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp,
|
|
struct iattr *iap)
|
|
{
|
|
struct inode *inode = d_inode(fhp->fh_dentry);
|
|
|
|
if (iap->ia_size < inode->i_size) {
|
|
__be32 err;
|
|
|
|
err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
|
|
NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE);
|
|
if (err)
|
|
return err;
|
|
}
|
|
return nfserrno(get_write_access(inode));
|
|
}
|
|
|
|
/*
|
|
* Set various file attributes. After this call fhp needs an fh_put.
|
|
*/
|
|
__be32
|
|
nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
|
|
int check_guard, time64_t guardtime)
|
|
{
|
|
struct dentry *dentry;
|
|
struct inode *inode;
|
|
int accmode = NFSD_MAY_SATTR;
|
|
umode_t ftype = 0;
|
|
__be32 err;
|
|
int host_err;
|
|
bool get_write_count;
|
|
bool size_change = (iap->ia_valid & ATTR_SIZE);
|
|
|
|
if (iap->ia_valid & ATTR_SIZE) {
|
|
accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
|
|
ftype = S_IFREG;
|
|
}
|
|
|
|
/*
|
|
* If utimes(2) and friends are called with times not NULL, we should
|
|
* not set NFSD_MAY_WRITE bit. Otherwise fh_verify->nfsd_permission
|
|
* will return EACCES, when the caller's effective UID does not match
|
|
* the owner of the file, and the caller is not privileged. In this
|
|
* situation, we should return EPERM(notify_change will return this).
|
|
*/
|
|
if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME)) {
|
|
accmode |= NFSD_MAY_OWNER_OVERRIDE;
|
|
if (!(iap->ia_valid & (ATTR_ATIME_SET | ATTR_MTIME_SET)))
|
|
accmode |= NFSD_MAY_WRITE;
|
|
}
|
|
|
|
/* Callers that do fh_verify should do the fh_want_write: */
|
|
get_write_count = !fhp->fh_dentry;
|
|
|
|
/* Get inode */
|
|
err = fh_verify(rqstp, fhp, ftype, accmode);
|
|
if (err)
|
|
return err;
|
|
if (get_write_count) {
|
|
host_err = fh_want_write(fhp);
|
|
if (host_err)
|
|
goto out;
|
|
}
|
|
|
|
dentry = fhp->fh_dentry;
|
|
inode = d_inode(dentry);
|
|
|
|
/* Ignore any mode updates on symlinks */
|
|
if (S_ISLNK(inode->i_mode))
|
|
iap->ia_valid &= ~ATTR_MODE;
|
|
|
|
if (!iap->ia_valid)
|
|
return 0;
|
|
|
|
nfsd_sanitize_attrs(inode, iap);
|
|
|
|
if (check_guard && guardtime != inode->i_ctime.tv_sec)
|
|
return nfserr_notsync;
|
|
|
|
/*
|
|
* The size case is special, it changes the file in addition to the
|
|
* attributes, and file systems don't expect it to be mixed with
|
|
* "random" attribute changes. We thus split out the size change
|
|
* into a separate call to ->setattr, and do the rest as a separate
|
|
* setattr call.
|
|
*/
|
|
if (size_change) {
|
|
err = nfsd_get_write_access(rqstp, fhp, iap);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
fh_lock(fhp);
|
|
if (size_change) {
|
|
/*
|
|
* RFC5661, Section 18.30.4:
|
|
* Changing the size of a file with SETATTR indirectly
|
|
* changes the time_modify and change attributes.
|
|
*
|
|
* (and similar for the older RFCs)
|
|
*/
|
|
struct iattr size_attr = {
|
|
.ia_valid = ATTR_SIZE | ATTR_CTIME | ATTR_MTIME,
|
|
.ia_size = iap->ia_size,
|
|
};
|
|
|
|
host_err = -EFBIG;
|
|
if (iap->ia_size < 0)
|
|
goto out_unlock;
|
|
|
|
host_err = notify_change(&init_user_ns, dentry, &size_attr, NULL);
|
|
if (host_err)
|
|
goto out_unlock;
|
|
iap->ia_valid &= ~ATTR_SIZE;
|
|
|
|
/*
|
|
* Avoid the additional setattr call below if the only other
|
|
* attribute that the client sends is the mtime, as we update
|
|
* it as part of the size change above.
|
|
*/
|
|
if ((iap->ia_valid & ~ATTR_MTIME) == 0)
|
|
goto out_unlock;
|
|
}
|
|
|
|
iap->ia_valid |= ATTR_CTIME;
|
|
host_err = notify_change(&init_user_ns, dentry, iap, NULL);
|
|
|
|
out_unlock:
|
|
fh_unlock(fhp);
|
|
if (size_change)
|
|
put_write_access(inode);
|
|
out:
|
|
if (!host_err)
|
|
host_err = commit_metadata(fhp);
|
|
return nfserrno(host_err);
|
|
}
|
|
|
|
#if defined(CONFIG_NFSD_V4)
|
|
/*
|
|
* NFS junction information is stored in an extended attribute.
|
|
*/
|
|
#define NFSD_JUNCTION_XATTR_NAME XATTR_TRUSTED_PREFIX "junction.nfs"
|
|
|
|
/**
|
|
* nfsd4_is_junction - Test if an object could be an NFS junction
|
|
*
|
|
* @dentry: object to test
|
|
*
|
|
* Returns 1 if "dentry" appears to contain NFS junction information.
|
|
* Otherwise 0 is returned.
|
|
*/
|
|
int nfsd4_is_junction(struct dentry *dentry)
|
|
{
|
|
struct inode *inode = d_inode(dentry);
|
|
|
|
if (inode == NULL)
|
|
return 0;
|
|
if (inode->i_mode & S_IXUGO)
|
|
return 0;
|
|
if (!(inode->i_mode & S_ISVTX))
|
|
return 0;
|
|
if (vfs_getxattr(&init_user_ns, dentry, NFSD_JUNCTION_XATTR_NAME,
|
|
NULL, 0) <= 0)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
|
|
__be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
|
|
struct xdr_netobj *label)
|
|
{
|
|
__be32 error;
|
|
int host_error;
|
|
struct dentry *dentry;
|
|
|
|
error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR);
|
|
if (error)
|
|
return error;
|
|
|
|
dentry = fhp->fh_dentry;
|
|
|
|
inode_lock(d_inode(dentry));
|
|
host_error = security_inode_setsecctx(dentry, label->data, label->len);
|
|
inode_unlock(d_inode(dentry));
|
|
return nfserrno(host_error);
|
|
}
|
|
#else
|
|
__be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
|
|
struct xdr_netobj *label)
|
|
{
|
|
return nfserr_notsupp;
|
|
}
|
|
#endif
|
|
|
|
static struct nfsd4_compound_state *nfsd4_get_cstate(struct svc_rqst *rqstp)
|
|
{
|
|
return &((struct nfsd4_compoundres *)rqstp->rq_resp)->cstate;
|
|
}
|
|
|
|
__be32 nfsd4_clone_file_range(struct svc_rqst *rqstp,
|
|
struct nfsd_file *nf_src, u64 src_pos,
|
|
struct nfsd_file *nf_dst, u64 dst_pos,
|
|
u64 count, bool sync)
|
|
{
|
|
struct file *src = nf_src->nf_file;
|
|
struct file *dst = nf_dst->nf_file;
|
|
errseq_t since;
|
|
loff_t cloned;
|
|
__be32 ret = 0;
|
|
|
|
since = READ_ONCE(dst->f_wb_err);
|
|
cloned = vfs_clone_file_range(src, src_pos, dst, dst_pos, count, 0);
|
|
if (cloned < 0) {
|
|
ret = nfserrno(cloned);
|
|
goto out_err;
|
|
}
|
|
if (count && cloned != count) {
|
|
ret = nfserrno(-EINVAL);
|
|
goto out_err;
|
|
}
|
|
if (sync) {
|
|
loff_t dst_end = count ? dst_pos + count - 1 : LLONG_MAX;
|
|
int status = vfs_fsync_range(dst, dst_pos, dst_end, 0);
|
|
|
|
if (!status)
|
|
status = filemap_check_wb_err(dst->f_mapping, since);
|
|
if (!status)
|
|
status = commit_inode_metadata(file_inode(src));
|
|
if (status < 0) {
|
|
struct nfsd_net *nn = net_generic(nf_dst->nf_net,
|
|
nfsd_net_id);
|
|
|
|
trace_nfsd_clone_file_range_err(rqstp,
|
|
&nfsd4_get_cstate(rqstp)->save_fh,
|
|
src_pos,
|
|
&nfsd4_get_cstate(rqstp)->current_fh,
|
|
dst_pos,
|
|
count, status);
|
|
nfsd_reset_write_verifier(nn);
|
|
trace_nfsd_writeverf_reset(nn, rqstp, status);
|
|
ret = nfserrno(status);
|
|
}
|
|
}
|
|
out_err:
|
|
return ret;
|
|
}
|
|
|
|
ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
|
|
u64 dst_pos, u64 count)
|
|
{
|
|
ssize_t ret;
|
|
|
|
/*
|
|
* Limit copy to 4MB to prevent indefinitely blocking an nfsd
|
|
* thread and client rpc slot. The choice of 4MB is somewhat
|
|
* arbitrary. We might instead base this on r/wsize, or make it
|
|
* tunable, or use a time instead of a byte limit, or implement
|
|
* asynchronous copy. In theory a client could also recognize a
|
|
* limit like this and pipeline multiple COPY requests.
|
|
*/
|
|
count = min_t(u64, count, 1 << 22);
|
|
ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
|
|
|
|
if (ret == -EOPNOTSUPP || ret == -EXDEV)
|
|
ret = generic_copy_file_range(src, src_pos, dst, dst_pos,
|
|
count, 0);
|
|
return ret;
|
|
}
|
|
|
|
__be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp,
|
|
struct file *file, loff_t offset, loff_t len,
|
|
int flags)
|
|
{
|
|
int error;
|
|
|
|
if (!S_ISREG(file_inode(file)->i_mode))
|
|
return nfserr_inval;
|
|
|
|
error = vfs_fallocate(file, flags, offset, len);
|
|
if (!error)
|
|
error = commit_metadata(fhp);
|
|
|
|
return nfserrno(error);
|
|
}
|
|
#endif /* defined(CONFIG_NFSD_V4) */
|
|
|
|
/*
|
|
* Check server access rights to a file system object
|
|
*/
|
|
struct accessmap {
|
|
u32 access;
|
|
int how;
|
|
};
|
|
static struct accessmap nfs3_regaccess[] = {
|
|
{ NFS3_ACCESS_READ, NFSD_MAY_READ },
|
|
{ NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
|
|
{ NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC },
|
|
{ NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE },
|
|
|
|
#ifdef CONFIG_NFSD_V4
|
|
{ NFS4_ACCESS_XAREAD, NFSD_MAY_READ },
|
|
{ NFS4_ACCESS_XAWRITE, NFSD_MAY_WRITE },
|
|
{ NFS4_ACCESS_XALIST, NFSD_MAY_READ },
|
|
#endif
|
|
|
|
{ 0, 0 }
|
|
};
|
|
|
|
static struct accessmap nfs3_diraccess[] = {
|
|
{ NFS3_ACCESS_READ, NFSD_MAY_READ },
|
|
{ NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC },
|
|
{ NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC},
|
|
{ NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE },
|
|
{ NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE },
|
|
|
|
#ifdef CONFIG_NFSD_V4
|
|
{ NFS4_ACCESS_XAREAD, NFSD_MAY_READ },
|
|
{ NFS4_ACCESS_XAWRITE, NFSD_MAY_WRITE },
|
|
{ NFS4_ACCESS_XALIST, NFSD_MAY_READ },
|
|
#endif
|
|
|
|
{ 0, 0 }
|
|
};
|
|
|
|
static struct accessmap nfs3_anyaccess[] = {
|
|
/* Some clients - Solaris 2.6 at least, make an access call
|
|
* to the server to check for access for things like /dev/null
|
|
* (which really, the server doesn't care about). So
|
|
* We provide simple access checking for them, looking
|
|
* mainly at mode bits, and we make sure to ignore read-only
|
|
* filesystem checks
|
|
*/
|
|
{ NFS3_ACCESS_READ, NFSD_MAY_READ },
|
|
{ NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
|
|
{ NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
|
|
{ NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
|
|
|
|
{ 0, 0 }
|
|
};
|
|
|
|
__be32
|
|
nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
|
|
{
|
|
struct accessmap *map;
|
|
struct svc_export *export;
|
|
struct dentry *dentry;
|
|
u32 query, result = 0, sresult = 0;
|
|
__be32 error;
|
|
|
|
error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
|
|
if (error)
|
|
goto out;
|
|
|
|
export = fhp->fh_export;
|
|
dentry = fhp->fh_dentry;
|
|
|
|
if (d_is_reg(dentry))
|
|
map = nfs3_regaccess;
|
|
else if (d_is_dir(dentry))
|
|
map = nfs3_diraccess;
|
|
else
|
|
map = nfs3_anyaccess;
|
|
|
|
|
|
query = *access;
|
|
for (; map->access; map++) {
|
|
if (map->access & query) {
|
|
__be32 err2;
|
|
|
|
sresult |= map->access;
|
|
|
|
err2 = nfsd_permission(rqstp, export, dentry, map->how);
|
|
switch (err2) {
|
|
case nfs_ok:
|
|
result |= map->access;
|
|
break;
|
|
|
|
/* the following error codes just mean the access was not allowed,
|
|
* rather than an error occurred */
|
|
case nfserr_rofs:
|
|
case nfserr_acces:
|
|
case nfserr_perm:
|
|
/* simply don't "or" in the access bit. */
|
|
break;
|
|
default:
|
|
error = err2;
|
|
goto out;
|
|
}
|
|
}
|
|
}
|
|
*access = result;
|
|
if (supported)
|
|
*supported = sresult;
|
|
|
|
out:
|
|
return error;
|
|
}
|
|
|
|
int nfsd_open_break_lease(struct inode *inode, int access)
|
|
{
|
|
unsigned int mode;
|
|
|
|
if (access & NFSD_MAY_NOT_BREAK_LEASE)
|
|
return 0;
|
|
mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY;
|
|
return break_lease(inode, mode | O_NONBLOCK);
|
|
}
|
|
|
|
/*
|
|
* Open an existing file or directory.
|
|
* The may_flags argument indicates the type of open (read/write/lock)
|
|
* and additional flags.
|
|
* N.B. After this call fhp needs an fh_put
|
|
*/
|
|
static __be32
|
|
__nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
|
|
int may_flags, struct file **filp)
|
|
{
|
|
struct path path;
|
|
struct inode *inode;
|
|
struct file *file;
|
|
int flags = O_RDONLY|O_LARGEFILE;
|
|
__be32 err;
|
|
int host_err = 0;
|
|
|
|
path.mnt = fhp->fh_export->ex_path.mnt;
|
|
path.dentry = fhp->fh_dentry;
|
|
inode = d_inode(path.dentry);
|
|
|
|
err = nfserr_perm;
|
|
if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE))
|
|
goto out;
|
|
|
|
if (!inode->i_fop)
|
|
goto out;
|
|
|
|
host_err = nfsd_open_break_lease(inode, may_flags);
|
|
if (host_err) /* NOMEM or WOULDBLOCK */
|
|
goto out_nfserr;
|
|
|
|
if (may_flags & NFSD_MAY_WRITE) {
|
|
if (may_flags & NFSD_MAY_READ)
|
|
flags = O_RDWR|O_LARGEFILE;
|
|
else
|
|
flags = O_WRONLY|O_LARGEFILE;
|
|
}
|
|
|
|
file = dentry_open(&path, flags, current_cred());
|
|
if (IS_ERR(file)) {
|
|
host_err = PTR_ERR(file);
|
|
goto out_nfserr;
|
|
}
|
|
|
|
host_err = ima_file_check(file, may_flags);
|
|
if (host_err) {
|
|
fput(file);
|
|
goto out_nfserr;
|
|
}
|
|
|
|
if (may_flags & NFSD_MAY_64BIT_COOKIE)
|
|
file->f_mode |= FMODE_64BITHASH;
|
|
else
|
|
file->f_mode |= FMODE_32BITHASH;
|
|
|
|
*filp = file;
|
|
out_nfserr:
|
|
err = nfserrno(host_err);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
__be32
|
|
nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
|
|
int may_flags, struct file **filp)
|
|
{
|
|
__be32 err;
|
|
bool retried = false;
|
|
|
|
validate_process_creds();
|
|
/*
|
|
* If we get here, then the client has already done an "open",
|
|
* and (hopefully) checked permission - so allow OWNER_OVERRIDE
|
|
* in case a chmod has now revoked permission.
|
|
*
|
|
* Arguably we should also allow the owner override for
|
|
* directories, but we never have and it doesn't seem to have
|
|
* caused anyone a problem. If we were to change this, note
|
|
* also that our filldir callbacks would need a variant of
|
|
* lookup_one_len that doesn't check permissions.
|
|
*/
|
|
if (type == S_IFREG)
|
|
may_flags |= NFSD_MAY_OWNER_OVERRIDE;
|
|
retry:
|
|
err = fh_verify(rqstp, fhp, type, may_flags);
|
|
if (!err) {
|
|
err = __nfsd_open(rqstp, fhp, type, may_flags, filp);
|
|
if (err == nfserr_stale && !retried) {
|
|
retried = true;
|
|
fh_put(fhp);
|
|
goto retry;
|
|
}
|
|
}
|
|
validate_process_creds();
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* nfsd_open_verified - Open a regular file for the filecache
|
|
* @rqstp: RPC request
|
|
* @fhp: NFS filehandle of the file to open
|
|
* @may_flags: internal permission flags
|
|
* @filp: OUT: open "struct file *"
|
|
*
|
|
* Returns an nfsstat value in network byte order.
|
|
*/
|
|
__be32
|
|
nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, int may_flags,
|
|
struct file **filp)
|
|
{
|
|
__be32 err;
|
|
|
|
validate_process_creds();
|
|
err = __nfsd_open(rqstp, fhp, S_IFREG, may_flags, filp);
|
|
validate_process_creds();
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Grab and keep cached pages associated with a file in the svc_rqst
|
|
* so that they can be passed to the network sendmsg/sendpage routines
|
|
* directly. They will be released after the sending has completed.
|
|
*/
|
|
static int
|
|
nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
|
|
struct splice_desc *sd)
|
|
{
|
|
struct svc_rqst *rqstp = sd->u.data;
|
|
|
|
svc_rqst_replace_page(rqstp, buf->page);
|
|
if (rqstp->rq_res.page_len == 0)
|
|
rqstp->rq_res.page_base = buf->offset;
|
|
rqstp->rq_res.page_len += sd->len;
|
|
return sd->len;
|
|
}
|
|
|
|
static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
|
|
struct splice_desc *sd)
|
|
{
|
|
return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
|
|
}
|
|
|
|
static u32 nfsd_eof_on_read(struct file *file, loff_t offset, ssize_t len,
|
|
size_t expected)
|
|
{
|
|
if (expected != 0 && len == 0)
|
|
return 1;
|
|
if (offset+len >= i_size_read(file_inode(file)))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static __be32 nfsd_finish_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
|
|
struct file *file, loff_t offset,
|
|
unsigned long *count, u32 *eof, ssize_t host_err)
|
|
{
|
|
if (host_err >= 0) {
|
|
nfsd_stats_io_read_add(fhp->fh_export, host_err);
|
|
*eof = nfsd_eof_on_read(file, offset, host_err, *count);
|
|
*count = host_err;
|
|
fsnotify_access(file);
|
|
trace_nfsd_read_io_done(rqstp, fhp, offset, *count);
|
|
return 0;
|
|
} else {
|
|
trace_nfsd_read_err(rqstp, fhp, offset, host_err);
|
|
return nfserrno(host_err);
|
|
}
|
|
}
|
|
|
|
__be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
|
|
struct file *file, loff_t offset, unsigned long *count,
|
|
u32 *eof)
|
|
{
|
|
struct splice_desc sd = {
|
|
.len = 0,
|
|
.total_len = *count,
|
|
.pos = offset,
|
|
.u.data = rqstp,
|
|
};
|
|
ssize_t host_err;
|
|
|
|
trace_nfsd_read_splice(rqstp, fhp, offset, *count);
|
|
rqstp->rq_next_page = rqstp->rq_respages + 1;
|
|
host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
|
|
return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
|
|
}
|
|
|
|
__be32 nfsd_readv(struct svc_rqst *rqstp, struct svc_fh *fhp,
|
|
struct file *file, loff_t offset,
|
|
struct kvec *vec, int vlen, unsigned long *count,
|
|
u32 *eof)
|
|
{
|
|
struct iov_iter iter;
|
|
loff_t ppos = offset;
|
|
ssize_t host_err;
|
|
|
|
trace_nfsd_read_vector(rqstp, fhp, offset, *count);
|
|
iov_iter_kvec(&iter, READ, vec, vlen, *count);
|
|
host_err = vfs_iter_read(file, &iter, &ppos, 0);
|
|
return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
|
|
}
|
|
|
|
/*
|
|
* Gathered writes: If another process is currently writing to the file,
|
|
* there's a high chance this is another nfsd (triggered by a bulk write
|
|
* from a client's biod). Rather than syncing the file with each write
|
|
* request, we sleep for 10 msec.
|
|
*
|
|
* I don't know if this roughly approximates C. Juszak's idea of
|
|
* gathered writes, but it's a nice and simple solution (IMHO), and it
|
|
* seems to work:-)
|
|
*
|
|
* Note: we do this only in the NFSv2 case, since v3 and higher have a
|
|
* better tool (separate unstable writes and commits) for solving this
|
|
* problem.
|
|
*/
|
|
static int wait_for_concurrent_writes(struct file *file)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
static ino_t last_ino;
|
|
static dev_t last_dev;
|
|
int err = 0;
|
|
|
|
if (atomic_read(&inode->i_writecount) > 1
|
|
|| (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
|
|
dprintk("nfsd: write defer %d\n", task_pid_nr(current));
|
|
msleep(10);
|
|
dprintk("nfsd: write resume %d\n", task_pid_nr(current));
|
|
}
|
|
|
|
if (inode->i_state & I_DIRTY) {
|
|
dprintk("nfsd: write sync %d\n", task_pid_nr(current));
|
|
err = vfs_fsync(file, 0);
|
|
}
|
|
last_ino = inode->i_ino;
|
|
last_dev = inode->i_sb->s_dev;
|
|
return err;
|
|
}
|
|
|
|
__be32
|
|
nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
|
|
loff_t offset, struct kvec *vec, int vlen,
|
|
unsigned long *cnt, int stable,
|
|
__be32 *verf)
|
|
{
|
|
struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
|
|
struct file *file = nf->nf_file;
|
|
struct super_block *sb = file_inode(file)->i_sb;
|
|
struct svc_export *exp;
|
|
struct iov_iter iter;
|
|
errseq_t since;
|
|
__be32 nfserr;
|
|
int host_err;
|
|
int use_wgather;
|
|
loff_t pos = offset;
|
|
unsigned long exp_op_flags = 0;
|
|
unsigned int pflags = current->flags;
|
|
rwf_t flags = 0;
|
|
bool restore_flags = false;
|
|
|
|
trace_nfsd_write_opened(rqstp, fhp, offset, *cnt);
|
|
|
|
if (sb->s_export_op)
|
|
exp_op_flags = sb->s_export_op->flags;
|
|
|
|
if (test_bit(RQ_LOCAL, &rqstp->rq_flags) &&
|
|
!(exp_op_flags & EXPORT_OP_REMOTE_FS)) {
|
|
/*
|
|
* We want throttling in balance_dirty_pages()
|
|
* and shrink_inactive_list() to only consider
|
|
* the backingdev we are writing to, so that nfs to
|
|
* localhost doesn't cause nfsd to lock up due to all
|
|
* the client's dirty pages or its congested queue.
|
|
*/
|
|
current->flags |= PF_LOCAL_THROTTLE;
|
|
restore_flags = true;
|
|
}
|
|
|
|
exp = fhp->fh_export;
|
|
use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
|
|
|
|
if (!EX_ISSYNC(exp))
|
|
stable = NFS_UNSTABLE;
|
|
|
|
if (stable && !use_wgather)
|
|
flags |= RWF_SYNC;
|
|
|
|
iov_iter_kvec(&iter, WRITE, vec, vlen, *cnt);
|
|
since = READ_ONCE(file->f_wb_err);
|
|
if (verf)
|
|
nfsd_copy_write_verifier(verf, nn);
|
|
host_err = vfs_iter_write(file, &iter, &pos, flags);
|
|
if (host_err < 0) {
|
|
nfsd_reset_write_verifier(nn);
|
|
trace_nfsd_writeverf_reset(nn, rqstp, host_err);
|
|
goto out_nfserr;
|
|
}
|
|
*cnt = host_err;
|
|
nfsd_stats_io_write_add(exp, *cnt);
|
|
fsnotify_modify(file);
|
|
host_err = filemap_check_wb_err(file->f_mapping, since);
|
|
if (host_err < 0)
|
|
goto out_nfserr;
|
|
|
|
if (stable && use_wgather) {
|
|
host_err = wait_for_concurrent_writes(file);
|
|
if (host_err < 0) {
|
|
nfsd_reset_write_verifier(nn);
|
|
trace_nfsd_writeverf_reset(nn, rqstp, host_err);
|
|
}
|
|
}
|
|
|
|
out_nfserr:
|
|
if (host_err >= 0) {
|
|
trace_nfsd_write_io_done(rqstp, fhp, offset, *cnt);
|
|
nfserr = nfs_ok;
|
|
} else {
|
|
trace_nfsd_write_err(rqstp, fhp, offset, host_err);
|
|
nfserr = nfserrno(host_err);
|
|
}
|
|
if (restore_flags)
|
|
current_restore_flags(pflags, PF_LOCAL_THROTTLE);
|
|
return nfserr;
|
|
}
|
|
|
|
/*
|
|
* Read data from a file. count must contain the requested read count
|
|
* on entry. On return, *count contains the number of bytes actually read.
|
|
* N.B. After this call fhp needs an fh_put
|
|
*/
|
|
__be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
|
|
loff_t offset, struct kvec *vec, int vlen, unsigned long *count,
|
|
u32 *eof)
|
|
{
|
|
struct nfsd_file *nf;
|
|
struct file *file;
|
|
__be32 err;
|
|
|
|
trace_nfsd_read_start(rqstp, fhp, offset, *count);
|
|
err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_READ, &nf);
|
|
if (err)
|
|
return err;
|
|
|
|
file = nf->nf_file;
|
|
if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags))
|
|
err = nfsd_splice_read(rqstp, fhp, file, offset, count, eof);
|
|
else
|
|
err = nfsd_readv(rqstp, fhp, file, offset, vec, vlen, count, eof);
|
|
|
|
nfsd_file_put(nf);
|
|
|
|
trace_nfsd_read_done(rqstp, fhp, offset, *count);
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Write data to a file.
|
|
* The stable flag requests synchronous writes.
|
|
* N.B. After this call fhp needs an fh_put
|
|
*/
|
|
__be32
|
|
nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
|
|
struct kvec *vec, int vlen, unsigned long *cnt, int stable,
|
|
__be32 *verf)
|
|
{
|
|
struct nfsd_file *nf;
|
|
__be32 err;
|
|
|
|
trace_nfsd_write_start(rqstp, fhp, offset, *cnt);
|
|
|
|
err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_WRITE, &nf);
|
|
if (err)
|
|
goto out;
|
|
|
|
err = nfsd_vfs_write(rqstp, fhp, nf, offset, vec,
|
|
vlen, cnt, stable, verf);
|
|
nfsd_file_put(nf);
|
|
out:
|
|
trace_nfsd_write_done(rqstp, fhp, offset, *cnt);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* nfsd_commit - Commit pending writes to stable storage
|
|
* @rqstp: RPC request being processed
|
|
* @fhp: NFS filehandle
|
|
* @offset: raw offset from beginning of file
|
|
* @count: raw count of bytes to sync
|
|
* @verf: filled in with the server's current write verifier
|
|
*
|
|
* Note: we guarantee that data that lies within the range specified
|
|
* by the 'offset' and 'count' parameters will be synced. The server
|
|
* is permitted to sync data that lies outside this range at the
|
|
* same time.
|
|
*
|
|
* Unfortunately we cannot lock the file to make sure we return full WCC
|
|
* data to the client, as locking happens lower down in the filesystem.
|
|
*
|
|
* Return values:
|
|
* An nfsstat value in network byte order.
|
|
*/
|
|
__be32
|
|
nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, u64 offset,
|
|
u32 count, __be32 *verf)
|
|
{
|
|
u64 maxbytes;
|
|
loff_t start, end;
|
|
struct nfsd_net *nn;
|
|
struct nfsd_file *nf;
|
|
__be32 err;
|
|
|
|
err = nfsd_file_acquire(rqstp, fhp,
|
|
NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &nf);
|
|
if (err)
|
|
goto out;
|
|
|
|
/*
|
|
* Convert the client-provided (offset, count) range to a
|
|
* (start, end) range. If the client-provided range falls
|
|
* outside the maximum file size of the underlying FS,
|
|
* clamp the sync range appropriately.
|
|
*/
|
|
start = 0;
|
|
end = LLONG_MAX;
|
|
maxbytes = (u64)fhp->fh_dentry->d_sb->s_maxbytes;
|
|
if (offset < maxbytes) {
|
|
start = offset;
|
|
if (count && (offset + count - 1 < maxbytes))
|
|
end = offset + count - 1;
|
|
}
|
|
|
|
nn = net_generic(nf->nf_net, nfsd_net_id);
|
|
if (EX_ISSYNC(fhp->fh_export)) {
|
|
errseq_t since = READ_ONCE(nf->nf_file->f_wb_err);
|
|
int err2;
|
|
|
|
err2 = vfs_fsync_range(nf->nf_file, start, end, 0);
|
|
switch (err2) {
|
|
case 0:
|
|
nfsd_copy_write_verifier(verf, nn);
|
|
err2 = filemap_check_wb_err(nf->nf_file->f_mapping,
|
|
since);
|
|
err = nfserrno(err2);
|
|
break;
|
|
case -EINVAL:
|
|
err = nfserr_notsupp;
|
|
break;
|
|
default:
|
|
nfsd_reset_write_verifier(nn);
|
|
trace_nfsd_writeverf_reset(nn, rqstp, err2);
|
|
err = nfserrno(err2);
|
|
}
|
|
} else
|
|
nfsd_copy_write_verifier(verf, nn);
|
|
|
|
nfsd_file_put(nf);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* nfsd_create_setattr - Set a created file's attributes
|
|
* @rqstp: RPC transaction being executed
|
|
* @fhp: NFS filehandle of parent directory
|
|
* @resfhp: NFS filehandle of new object
|
|
* @iap: requested attributes of new object
|
|
*
|
|
* Returns nfs_ok on success, or an nfsstat in network byte order.
|
|
*/
|
|
__be32
|
|
nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
|
|
struct svc_fh *resfhp, struct iattr *iap)
|
|
{
|
|
__be32 status;
|
|
|
|
/*
|
|
* Mode has already been set by file creation.
|
|
*/
|
|
iap->ia_valid &= ~ATTR_MODE;
|
|
|
|
/*
|
|
* Setting uid/gid works only for root. Irix appears to
|
|
* send along the gid on create when it tries to implement
|
|
* setgid directories via NFS:
|
|
*/
|
|
if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID))
|
|
iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
|
|
|
|
/*
|
|
* Callers expect new file metadata to be committed even
|
|
* if the attributes have not changed.
|
|
*/
|
|
if (iap->ia_valid)
|
|
status = nfsd_setattr(rqstp, resfhp, iap, 0, (time64_t)0);
|
|
else
|
|
status = nfserrno(commit_metadata(resfhp));
|
|
|
|
/*
|
|
* Transactional filesystems had a chance to commit changes
|
|
* for both parent and child simultaneously making the
|
|
* following commit_metadata a noop in many cases.
|
|
*/
|
|
if (!status)
|
|
status = nfserrno(commit_metadata(fhp));
|
|
|
|
/*
|
|
* Update the new filehandle to pick up the new attributes.
|
|
*/
|
|
if (!status)
|
|
status = fh_update(resfhp);
|
|
|
|
return status;
|
|
}
|
|
|
|
/* HPUX client sometimes creates a file in mode 000, and sets size to 0.
|
|
* setting size to 0 may fail for some specific file systems by the permission
|
|
* checking which requires WRITE permission but the mode is 000.
|
|
* we ignore the resizing(to 0) on the just new created file, since the size is
|
|
* 0 after file created.
|
|
*
|
|
* call this only after vfs_create() is called.
|
|
* */
|
|
static void
|
|
nfsd_check_ignore_resizing(struct iattr *iap)
|
|
{
|
|
if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
|
|
iap->ia_valid &= ~ATTR_SIZE;
|
|
}
|
|
|
|
/* The parent directory should already be locked: */
|
|
__be32
|
|
nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
|
|
char *fname, int flen, struct iattr *iap,
|
|
int type, dev_t rdev, struct svc_fh *resfhp)
|
|
{
|
|
struct dentry *dentry, *dchild;
|
|
struct inode *dirp;
|
|
__be32 err;
|
|
int host_err;
|
|
|
|
dentry = fhp->fh_dentry;
|
|
dirp = d_inode(dentry);
|
|
|
|
dchild = dget(resfhp->fh_dentry);
|
|
if (!fhp->fh_locked) {
|
|
WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n",
|
|
dentry);
|
|
err = nfserr_io;
|
|
goto out;
|
|
}
|
|
|
|
err = nfsd_permission(rqstp, fhp->fh_export, dentry, NFSD_MAY_CREATE);
|
|
if (err)
|
|
goto out;
|
|
|
|
if (!(iap->ia_valid & ATTR_MODE))
|
|
iap->ia_mode = 0;
|
|
iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
|
|
|
|
if (!IS_POSIXACL(dirp))
|
|
iap->ia_mode &= ~current_umask();
|
|
|
|
err = 0;
|
|
host_err = 0;
|
|
switch (type) {
|
|
case S_IFREG:
|
|
host_err = vfs_create(&init_user_ns, dirp, dchild, iap->ia_mode, true);
|
|
if (!host_err)
|
|
nfsd_check_ignore_resizing(iap);
|
|
break;
|
|
case S_IFDIR:
|
|
host_err = vfs_mkdir(&init_user_ns, dirp, dchild, iap->ia_mode);
|
|
if (!host_err && unlikely(d_unhashed(dchild))) {
|
|
struct dentry *d;
|
|
d = lookup_one_len(dchild->d_name.name,
|
|
dchild->d_parent,
|
|
dchild->d_name.len);
|
|
if (IS_ERR(d)) {
|
|
host_err = PTR_ERR(d);
|
|
break;
|
|
}
|
|
if (unlikely(d_is_negative(d))) {
|
|
dput(d);
|
|
err = nfserr_serverfault;
|
|
goto out;
|
|
}
|
|
dput(resfhp->fh_dentry);
|
|
resfhp->fh_dentry = dget(d);
|
|
err = fh_update(resfhp);
|
|
dput(dchild);
|
|
dchild = d;
|
|
if (err)
|
|
goto out;
|
|
}
|
|
break;
|
|
case S_IFCHR:
|
|
case S_IFBLK:
|
|
case S_IFIFO:
|
|
case S_IFSOCK:
|
|
host_err = vfs_mknod(&init_user_ns, dirp, dchild,
|
|
iap->ia_mode, rdev);
|
|
break;
|
|
default:
|
|
printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
|
|
type);
|
|
host_err = -EINVAL;
|
|
}
|
|
if (host_err < 0)
|
|
goto out_nfserr;
|
|
|
|
err = nfsd_create_setattr(rqstp, fhp, resfhp, iap);
|
|
|
|
out:
|
|
dput(dchild);
|
|
return err;
|
|
|
|
out_nfserr:
|
|
err = nfserrno(host_err);
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Create a filesystem object (regular, directory, special).
|
|
* Note that the parent directory is left locked.
|
|
*
|
|
* N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
|
|
*/
|
|
__be32
|
|
nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
|
|
char *fname, int flen, struct iattr *iap,
|
|
int type, dev_t rdev, struct svc_fh *resfhp)
|
|
{
|
|
struct dentry *dentry, *dchild = NULL;
|
|
__be32 err;
|
|
int host_err;
|
|
|
|
if (isdotent(fname, flen))
|
|
return nfserr_exist;
|
|
|
|
err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_NOP);
|
|
if (err)
|
|
return err;
|
|
|
|
dentry = fhp->fh_dentry;
|
|
|
|
host_err = fh_want_write(fhp);
|
|
if (host_err)
|
|
return nfserrno(host_err);
|
|
|
|
fh_lock_nested(fhp, I_MUTEX_PARENT);
|
|
dchild = lookup_one_len(fname, dentry, flen);
|
|
host_err = PTR_ERR(dchild);
|
|
if (IS_ERR(dchild))
|
|
return nfserrno(host_err);
|
|
err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
|
|
/*
|
|
* We unconditionally drop our ref to dchild as fh_compose will have
|
|
* already grabbed its own ref for it.
|
|
*/
|
|
dput(dchild);
|
|
if (err)
|
|
return err;
|
|
return nfsd_create_locked(rqstp, fhp, fname, flen, iap, type,
|
|
rdev, resfhp);
|
|
}
|
|
|
|
/*
|
|
* Read a symlink. On entry, *lenp must contain the maximum path length that
|
|
* fits into the buffer. On return, it contains the true length.
|
|
* N.B. After this call fhp needs an fh_put
|
|
*/
|
|
__be32
|
|
nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
|
|
{
|
|
__be32 err;
|
|
const char *link;
|
|
struct path path;
|
|
DEFINE_DELAYED_CALL(done);
|
|
int len;
|
|
|
|
err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
|
|
if (unlikely(err))
|
|
return err;
|
|
|
|
path.mnt = fhp->fh_export->ex_path.mnt;
|
|
path.dentry = fhp->fh_dentry;
|
|
|
|
if (unlikely(!d_is_symlink(path.dentry)))
|
|
return nfserr_inval;
|
|
|
|
touch_atime(&path);
|
|
|
|
link = vfs_get_link(path.dentry, &done);
|
|
if (IS_ERR(link))
|
|
return nfserrno(PTR_ERR(link));
|
|
|
|
len = strlen(link);
|
|
if (len < *lenp)
|
|
*lenp = len;
|
|
memcpy(buf, link, *lenp);
|
|
do_delayed_call(&done);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Create a symlink and look up its inode
|
|
* N.B. After this call _both_ fhp and resfhp need an fh_put
|
|
*/
|
|
__be32
|
|
nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
|
|
char *fname, int flen,
|
|
char *path,
|
|
struct svc_fh *resfhp)
|
|
{
|
|
struct dentry *dentry, *dnew;
|
|
__be32 err, cerr;
|
|
int host_err;
|
|
|
|
err = nfserr_noent;
|
|
if (!flen || path[0] == '\0')
|
|
goto out;
|
|
err = nfserr_exist;
|
|
if (isdotent(fname, flen))
|
|
goto out;
|
|
|
|
err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
|
|
if (err)
|
|
goto out;
|
|
|
|
host_err = fh_want_write(fhp);
|
|
if (host_err)
|
|
goto out_nfserr;
|
|
|
|
fh_lock(fhp);
|
|
dentry = fhp->fh_dentry;
|
|
dnew = lookup_one_len(fname, dentry, flen);
|
|
host_err = PTR_ERR(dnew);
|
|
if (IS_ERR(dnew))
|
|
goto out_nfserr;
|
|
|
|
host_err = vfs_symlink(&init_user_ns, d_inode(dentry), dnew, path);
|
|
err = nfserrno(host_err);
|
|
fh_unlock(fhp);
|
|
if (!err)
|
|
err = nfserrno(commit_metadata(fhp));
|
|
|
|
fh_drop_write(fhp);
|
|
|
|
cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
|
|
dput(dnew);
|
|
if (err==0) err = cerr;
|
|
out:
|
|
return err;
|
|
|
|
out_nfserr:
|
|
err = nfserrno(host_err);
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Create a hardlink
|
|
* N.B. After this call _both_ ffhp and tfhp need an fh_put
|
|
*/
|
|
__be32
|
|
nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
|
|
char *name, int len, struct svc_fh *tfhp)
|
|
{
|
|
struct dentry *ddir, *dnew, *dold;
|
|
struct inode *dirp;
|
|
__be32 err;
|
|
int host_err;
|
|
|
|
err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
|
|
if (err)
|
|
goto out;
|
|
err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP);
|
|
if (err)
|
|
goto out;
|
|
err = nfserr_isdir;
|
|
if (d_is_dir(tfhp->fh_dentry))
|
|
goto out;
|
|
err = nfserr_perm;
|
|
if (!len)
|
|
goto out;
|
|
err = nfserr_exist;
|
|
if (isdotent(name, len))
|
|
goto out;
|
|
|
|
host_err = fh_want_write(tfhp);
|
|
if (host_err) {
|
|
err = nfserrno(host_err);
|
|
goto out;
|
|
}
|
|
|
|
fh_lock_nested(ffhp, I_MUTEX_PARENT);
|
|
ddir = ffhp->fh_dentry;
|
|
dirp = d_inode(ddir);
|
|
|
|
dnew = lookup_one_len(name, ddir, len);
|
|
host_err = PTR_ERR(dnew);
|
|
if (IS_ERR(dnew))
|
|
goto out_nfserr;
|
|
|
|
dold = tfhp->fh_dentry;
|
|
|
|
err = nfserr_noent;
|
|
if (d_really_is_negative(dold))
|
|
goto out_dput;
|
|
host_err = vfs_link(dold, &init_user_ns, dirp, dnew, NULL);
|
|
fh_unlock(ffhp);
|
|
if (!host_err) {
|
|
err = nfserrno(commit_metadata(ffhp));
|
|
if (!err)
|
|
err = nfserrno(commit_metadata(tfhp));
|
|
} else {
|
|
if (host_err == -EXDEV && rqstp->rq_vers == 2)
|
|
err = nfserr_acces;
|
|
else
|
|
err = nfserrno(host_err);
|
|
}
|
|
out_dput:
|
|
dput(dnew);
|
|
out_unlock:
|
|
fh_unlock(ffhp);
|
|
fh_drop_write(tfhp);
|
|
out:
|
|
return err;
|
|
|
|
out_nfserr:
|
|
err = nfserrno(host_err);
|
|
goto out_unlock;
|
|
}
|
|
|
|
static void
|
|
nfsd_close_cached_files(struct dentry *dentry)
|
|
{
|
|
struct inode *inode = d_inode(dentry);
|
|
|
|
if (inode && S_ISREG(inode->i_mode))
|
|
nfsd_file_close_inode_sync(inode);
|
|
}
|
|
|
|
static bool
|
|
nfsd_has_cached_files(struct dentry *dentry)
|
|
{
|
|
bool ret = false;
|
|
struct inode *inode = d_inode(dentry);
|
|
|
|
if (inode && S_ISREG(inode->i_mode))
|
|
ret = nfsd_file_is_cached(inode);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Rename a file
|
|
* N.B. After this call _both_ ffhp and tfhp need an fh_put
|
|
*/
|
|
__be32
|
|
nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
|
|
struct svc_fh *tfhp, char *tname, int tlen)
|
|
{
|
|
struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap;
|
|
struct inode *fdir, *tdir;
|
|
__be32 err;
|
|
int host_err;
|
|
bool close_cached = false;
|
|
|
|
err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
|
|
if (err)
|
|
goto out;
|
|
err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
|
|
if (err)
|
|
goto out;
|
|
|
|
fdentry = ffhp->fh_dentry;
|
|
fdir = d_inode(fdentry);
|
|
|
|
tdentry = tfhp->fh_dentry;
|
|
tdir = d_inode(tdentry);
|
|
|
|
err = nfserr_perm;
|
|
if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
|
|
goto out;
|
|
|
|
retry:
|
|
host_err = fh_want_write(ffhp);
|
|
if (host_err) {
|
|
err = nfserrno(host_err);
|
|
goto out;
|
|
}
|
|
|
|
/* cannot use fh_lock as we need deadlock protective ordering
|
|
* so do it by hand */
|
|
trap = lock_rename(tdentry, fdentry);
|
|
ffhp->fh_locked = tfhp->fh_locked = true;
|
|
fh_fill_pre_attrs(ffhp);
|
|
fh_fill_pre_attrs(tfhp);
|
|
|
|
odentry = lookup_one_len(fname, fdentry, flen);
|
|
host_err = PTR_ERR(odentry);
|
|
if (IS_ERR(odentry))
|
|
goto out_nfserr;
|
|
|
|
host_err = -ENOENT;
|
|
if (d_really_is_negative(odentry))
|
|
goto out_dput_old;
|
|
host_err = -EINVAL;
|
|
if (odentry == trap)
|
|
goto out_dput_old;
|
|
|
|
ndentry = lookup_one_len(tname, tdentry, tlen);
|
|
host_err = PTR_ERR(ndentry);
|
|
if (IS_ERR(ndentry))
|
|
goto out_dput_old;
|
|
host_err = -ENOTEMPTY;
|
|
if (ndentry == trap)
|
|
goto out_dput_new;
|
|
|
|
host_err = -EXDEV;
|
|
if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
|
|
goto out_dput_new;
|
|
if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
|
|
goto out_dput_new;
|
|
|
|
if ((ndentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK) &&
|
|
nfsd_has_cached_files(ndentry)) {
|
|
close_cached = true;
|
|
goto out_dput_old;
|
|
} else {
|
|
struct renamedata rd = {
|
|
.old_mnt_userns = &init_user_ns,
|
|
.old_dir = fdir,
|
|
.old_dentry = odentry,
|
|
.new_mnt_userns = &init_user_ns,
|
|
.new_dir = tdir,
|
|
.new_dentry = ndentry,
|
|
};
|
|
host_err = vfs_rename(&rd);
|
|
if (!host_err) {
|
|
host_err = commit_metadata(tfhp);
|
|
if (!host_err)
|
|
host_err = commit_metadata(ffhp);
|
|
}
|
|
}
|
|
out_dput_new:
|
|
dput(ndentry);
|
|
out_dput_old:
|
|
dput(odentry);
|
|
out_nfserr:
|
|
err = nfserrno(host_err);
|
|
/*
|
|
* We cannot rely on fh_unlock on the two filehandles,
|
|
* as that would do the wrong thing if the two directories
|
|
* were the same, so again we do it by hand.
|
|
*/
|
|
if (!close_cached) {
|
|
fh_fill_post_attrs(ffhp);
|
|
fh_fill_post_attrs(tfhp);
|
|
}
|
|
unlock_rename(tdentry, fdentry);
|
|
ffhp->fh_locked = tfhp->fh_locked = false;
|
|
fh_drop_write(ffhp);
|
|
|
|
/*
|
|
* If the target dentry has cached open files, then we need to try to
|
|
* close them prior to doing the rename. Flushing delayed fput
|
|
* shouldn't be done with locks held however, so we delay it until this
|
|
* point and then reattempt the whole shebang.
|
|
*/
|
|
if (close_cached) {
|
|
close_cached = false;
|
|
nfsd_close_cached_files(ndentry);
|
|
dput(ndentry);
|
|
goto retry;
|
|
}
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Unlink a file or directory
|
|
* N.B. After this call fhp needs an fh_put
|
|
*/
|
|
__be32
|
|
nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
|
|
char *fname, int flen)
|
|
{
|
|
struct dentry *dentry, *rdentry;
|
|
struct inode *dirp;
|
|
struct inode *rinode;
|
|
__be32 err;
|
|
int host_err;
|
|
|
|
err = nfserr_acces;
|
|
if (!flen || isdotent(fname, flen))
|
|
goto out;
|
|
err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
|
|
if (err)
|
|
goto out;
|
|
|
|
host_err = fh_want_write(fhp);
|
|
if (host_err)
|
|
goto out_nfserr;
|
|
|
|
fh_lock_nested(fhp, I_MUTEX_PARENT);
|
|
dentry = fhp->fh_dentry;
|
|
dirp = d_inode(dentry);
|
|
|
|
rdentry = lookup_one_len(fname, dentry, flen);
|
|
host_err = PTR_ERR(rdentry);
|
|
if (IS_ERR(rdentry))
|
|
goto out_drop_write;
|
|
|
|
if (d_really_is_negative(rdentry)) {
|
|
dput(rdentry);
|
|
host_err = -ENOENT;
|
|
goto out_drop_write;
|
|
}
|
|
rinode = d_inode(rdentry);
|
|
ihold(rinode);
|
|
|
|
if (!type)
|
|
type = d_inode(rdentry)->i_mode & S_IFMT;
|
|
|
|
if (type != S_IFDIR) {
|
|
if (rdentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK)
|
|
nfsd_close_cached_files(rdentry);
|
|
host_err = vfs_unlink(&init_user_ns, dirp, rdentry, NULL);
|
|
} else {
|
|
host_err = vfs_rmdir(&init_user_ns, dirp, rdentry);
|
|
}
|
|
|
|
fh_unlock(fhp);
|
|
if (!host_err)
|
|
host_err = commit_metadata(fhp);
|
|
dput(rdentry);
|
|
iput(rinode); /* truncate the inode here */
|
|
|
|
out_drop_write:
|
|
fh_drop_write(fhp);
|
|
out_nfserr:
|
|
if (host_err == -EBUSY) {
|
|
/* name is mounted-on. There is no perfect
|
|
* error status.
|
|
*/
|
|
if (nfsd_v4client(rqstp))
|
|
err = nfserr_file_open;
|
|
else
|
|
err = nfserr_acces;
|
|
} else {
|
|
err = nfserrno(host_err);
|
|
}
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* We do this buffering because we must not call back into the file
|
|
* system's ->lookup() method from the filldir callback. That may well
|
|
* deadlock a number of file systems.
|
|
*
|
|
* This is based heavily on the implementation of same in XFS.
|
|
*/
|
|
struct buffered_dirent {
|
|
u64 ino;
|
|
loff_t offset;
|
|
int namlen;
|
|
unsigned int d_type;
|
|
char name[];
|
|
};
|
|
|
|
struct readdir_data {
|
|
struct dir_context ctx;
|
|
char *dirent;
|
|
size_t used;
|
|
int full;
|
|
};
|
|
|
|
static int nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
|
|
int namlen, loff_t offset, u64 ino,
|
|
unsigned int d_type)
|
|
{
|
|
struct readdir_data *buf =
|
|
container_of(ctx, struct readdir_data, ctx);
|
|
struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
|
|
unsigned int reclen;
|
|
|
|
reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
|
|
if (buf->used + reclen > PAGE_SIZE) {
|
|
buf->full = 1;
|
|
return -EINVAL;
|
|
}
|
|
|
|
de->namlen = namlen;
|
|
de->offset = offset;
|
|
de->ino = ino;
|
|
de->d_type = d_type;
|
|
memcpy(de->name, name, namlen);
|
|
buf->used += reclen;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static __be32 nfsd_buffered_readdir(struct file *file, struct svc_fh *fhp,
|
|
nfsd_filldir_t func, struct readdir_cd *cdp,
|
|
loff_t *offsetp)
|
|
{
|
|
struct buffered_dirent *de;
|
|
int host_err;
|
|
int size;
|
|
loff_t offset;
|
|
struct readdir_data buf = {
|
|
.ctx.actor = nfsd_buffered_filldir,
|
|
.dirent = (void *)__get_free_page(GFP_KERNEL)
|
|
};
|
|
|
|
if (!buf.dirent)
|
|
return nfserrno(-ENOMEM);
|
|
|
|
offset = *offsetp;
|
|
|
|
while (1) {
|
|
unsigned int reclen;
|
|
|
|
cdp->err = nfserr_eof; /* will be cleared on successful read */
|
|
buf.used = 0;
|
|
buf.full = 0;
|
|
|
|
host_err = iterate_dir(file, &buf.ctx);
|
|
if (buf.full)
|
|
host_err = 0;
|
|
|
|
if (host_err < 0)
|
|
break;
|
|
|
|
size = buf.used;
|
|
|
|
if (!size)
|
|
break;
|
|
|
|
de = (struct buffered_dirent *)buf.dirent;
|
|
while (size > 0) {
|
|
offset = de->offset;
|
|
|
|
if (func(cdp, de->name, de->namlen, de->offset,
|
|
de->ino, de->d_type))
|
|
break;
|
|
|
|
if (cdp->err != nfs_ok)
|
|
break;
|
|
|
|
trace_nfsd_dirent(fhp, de->ino, de->name, de->namlen);
|
|
|
|
reclen = ALIGN(sizeof(*de) + de->namlen,
|
|
sizeof(u64));
|
|
size -= reclen;
|
|
de = (struct buffered_dirent *)((char *)de + reclen);
|
|
}
|
|
if (size > 0) /* We bailed out early */
|
|
break;
|
|
|
|
offset = vfs_llseek(file, 0, SEEK_CUR);
|
|
}
|
|
|
|
free_page((unsigned long)(buf.dirent));
|
|
|
|
if (host_err)
|
|
return nfserrno(host_err);
|
|
|
|
*offsetp = offset;
|
|
return cdp->err;
|
|
}
|
|
|
|
/*
|
|
* Read entries from a directory.
|
|
* The NFSv3/4 verifier we ignore for now.
|
|
*/
|
|
__be32
|
|
nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
|
|
struct readdir_cd *cdp, nfsd_filldir_t func)
|
|
{
|
|
__be32 err;
|
|
struct file *file;
|
|
loff_t offset = *offsetp;
|
|
int may_flags = NFSD_MAY_READ;
|
|
|
|
/* NFSv2 only supports 32 bit cookies */
|
|
if (rqstp->rq_vers > 2)
|
|
may_flags |= NFSD_MAY_64BIT_COOKIE;
|
|
|
|
err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
|
|
if (err)
|
|
goto out;
|
|
|
|
offset = vfs_llseek(file, offset, SEEK_SET);
|
|
if (offset < 0) {
|
|
err = nfserrno((int)offset);
|
|
goto out_close;
|
|
}
|
|
|
|
err = nfsd_buffered_readdir(file, fhp, func, cdp, offsetp);
|
|
|
|
if (err == nfserr_eof || err == nfserr_toosmall)
|
|
err = nfs_ok; /* can still be found in ->err */
|
|
out_close:
|
|
fput(file);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Get file system stats
|
|
* N.B. After this call fhp needs an fh_put
|
|
*/
|
|
__be32
|
|
nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
|
|
{
|
|
__be32 err;
|
|
|
|
err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
|
|
if (!err) {
|
|
struct path path = {
|
|
.mnt = fhp->fh_export->ex_path.mnt,
|
|
.dentry = fhp->fh_dentry,
|
|
};
|
|
if (vfs_statfs(&path, stat))
|
|
err = nfserr_io;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
|
|
{
|
|
return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
|
|
}
|
|
|
|
#ifdef CONFIG_NFSD_V4
|
|
/*
|
|
* Helper function to translate error numbers. In the case of xattr operations,
|
|
* some error codes need to be translated outside of the standard translations.
|
|
*
|
|
* ENODATA needs to be translated to nfserr_noxattr.
|
|
* E2BIG to nfserr_xattr2big.
|
|
*
|
|
* Additionally, vfs_listxattr can return -ERANGE. This means that the
|
|
* file has too many extended attributes to retrieve inside an
|
|
* XATTR_LIST_MAX sized buffer. This is a bug in the xattr implementation:
|
|
* filesystems will allow the adding of extended attributes until they hit
|
|
* their own internal limit. This limit may be larger than XATTR_LIST_MAX.
|
|
* So, at that point, the attributes are present and valid, but can't
|
|
* be retrieved using listxattr, since the upper level xattr code enforces
|
|
* the XATTR_LIST_MAX limit.
|
|
*
|
|
* This bug means that we need to deal with listxattr returning -ERANGE. The
|
|
* best mapping is to return TOOSMALL.
|
|
*/
|
|
static __be32
|
|
nfsd_xattr_errno(int err)
|
|
{
|
|
switch (err) {
|
|
case -ENODATA:
|
|
return nfserr_noxattr;
|
|
case -E2BIG:
|
|
return nfserr_xattr2big;
|
|
case -ERANGE:
|
|
return nfserr_toosmall;
|
|
}
|
|
return nfserrno(err);
|
|
}
|
|
|
|
/*
|
|
* Retrieve the specified user extended attribute. To avoid always
|
|
* having to allocate the maximum size (since we are not getting
|
|
* a maximum size from the RPC), do a probe + alloc. Hold a reader
|
|
* lock on i_rwsem to prevent the extended attribute from changing
|
|
* size while we're doing this.
|
|
*/
|
|
__be32
|
|
nfsd_getxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
|
|
void **bufp, int *lenp)
|
|
{
|
|
ssize_t len;
|
|
__be32 err;
|
|
char *buf;
|
|
struct inode *inode;
|
|
struct dentry *dentry;
|
|
|
|
err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
|
|
if (err)
|
|
return err;
|
|
|
|
err = nfs_ok;
|
|
dentry = fhp->fh_dentry;
|
|
inode = d_inode(dentry);
|
|
|
|
inode_lock_shared(inode);
|
|
|
|
len = vfs_getxattr(&init_user_ns, dentry, name, NULL, 0);
|
|
|
|
/*
|
|
* Zero-length attribute, just return.
|
|
*/
|
|
if (len == 0) {
|
|
*bufp = NULL;
|
|
*lenp = 0;
|
|
goto out;
|
|
}
|
|
|
|
if (len < 0) {
|
|
err = nfsd_xattr_errno(len);
|
|
goto out;
|
|
}
|
|
|
|
if (len > *lenp) {
|
|
err = nfserr_toosmall;
|
|
goto out;
|
|
}
|
|
|
|
buf = kvmalloc(len, GFP_KERNEL | GFP_NOFS);
|
|
if (buf == NULL) {
|
|
err = nfserr_jukebox;
|
|
goto out;
|
|
}
|
|
|
|
len = vfs_getxattr(&init_user_ns, dentry, name, buf, len);
|
|
if (len <= 0) {
|
|
kvfree(buf);
|
|
buf = NULL;
|
|
err = nfsd_xattr_errno(len);
|
|
}
|
|
|
|
*lenp = len;
|
|
*bufp = buf;
|
|
|
|
out:
|
|
inode_unlock_shared(inode);
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Retrieve the xattr names. Since we can't know how many are
|
|
* user extended attributes, we must get all attributes here,
|
|
* and have the XDR encode filter out the "user." ones.
|
|
*
|
|
* While this could always just allocate an XATTR_LIST_MAX
|
|
* buffer, that's a waste, so do a probe + allocate. To
|
|
* avoid any changes between the probe and allocate, wrap
|
|
* this in inode_lock.
|
|
*/
|
|
__be32
|
|
nfsd_listxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char **bufp,
|
|
int *lenp)
|
|
{
|
|
ssize_t len;
|
|
__be32 err;
|
|
char *buf;
|
|
struct inode *inode;
|
|
struct dentry *dentry;
|
|
|
|
err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
|
|
if (err)
|
|
return err;
|
|
|
|
dentry = fhp->fh_dentry;
|
|
inode = d_inode(dentry);
|
|
*lenp = 0;
|
|
|
|
inode_lock_shared(inode);
|
|
|
|
len = vfs_listxattr(dentry, NULL, 0);
|
|
if (len <= 0) {
|
|
err = nfsd_xattr_errno(len);
|
|
goto out;
|
|
}
|
|
|
|
if (len > XATTR_LIST_MAX) {
|
|
err = nfserr_xattr2big;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* We're holding i_rwsem - use GFP_NOFS.
|
|
*/
|
|
buf = kvmalloc(len, GFP_KERNEL | GFP_NOFS);
|
|
if (buf == NULL) {
|
|
err = nfserr_jukebox;
|
|
goto out;
|
|
}
|
|
|
|
len = vfs_listxattr(dentry, buf, len);
|
|
if (len <= 0) {
|
|
kvfree(buf);
|
|
err = nfsd_xattr_errno(len);
|
|
goto out;
|
|
}
|
|
|
|
*lenp = len;
|
|
*bufp = buf;
|
|
|
|
err = nfs_ok;
|
|
out:
|
|
inode_unlock_shared(inode);
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Removexattr and setxattr need to call fh_lock to both lock the inode
|
|
* and set the change attribute. Since the top-level vfs_removexattr
|
|
* and vfs_setxattr calls already do their own inode_lock calls, call
|
|
* the _locked variant. Pass in a NULL pointer for delegated_inode,
|
|
* and let the client deal with NFS4ERR_DELAY (same as with e.g.
|
|
* setattr and remove).
|
|
*/
|
|
__be32
|
|
nfsd_removexattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name)
|
|
{
|
|
__be32 err;
|
|
int ret;
|
|
|
|
err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
|
|
if (err)
|
|
return err;
|
|
|
|
ret = fh_want_write(fhp);
|
|
if (ret)
|
|
return nfserrno(ret);
|
|
|
|
fh_lock(fhp);
|
|
|
|
ret = __vfs_removexattr_locked(&init_user_ns, fhp->fh_dentry,
|
|
name, NULL);
|
|
|
|
fh_unlock(fhp);
|
|
fh_drop_write(fhp);
|
|
|
|
return nfsd_xattr_errno(ret);
|
|
}
|
|
|
|
__be32
|
|
nfsd_setxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
|
|
void *buf, u32 len, u32 flags)
|
|
{
|
|
__be32 err;
|
|
int ret;
|
|
|
|
err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
|
|
if (err)
|
|
return err;
|
|
|
|
ret = fh_want_write(fhp);
|
|
if (ret)
|
|
return nfserrno(ret);
|
|
fh_lock(fhp);
|
|
|
|
ret = __vfs_setxattr_locked(&init_user_ns, fhp->fh_dentry, name, buf,
|
|
len, flags, NULL);
|
|
|
|
fh_unlock(fhp);
|
|
fh_drop_write(fhp);
|
|
|
|
return nfsd_xattr_errno(ret);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Check for a user's access permissions to this inode.
|
|
*/
|
|
__be32
|
|
nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
|
|
struct dentry *dentry, int acc)
|
|
{
|
|
struct inode *inode = d_inode(dentry);
|
|
int err;
|
|
|
|
if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP)
|
|
return 0;
|
|
#if 0
|
|
dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
|
|
acc,
|
|
(acc & NFSD_MAY_READ)? " read" : "",
|
|
(acc & NFSD_MAY_WRITE)? " write" : "",
|
|
(acc & NFSD_MAY_EXEC)? " exec" : "",
|
|
(acc & NFSD_MAY_SATTR)? " sattr" : "",
|
|
(acc & NFSD_MAY_TRUNC)? " trunc" : "",
|
|
(acc & NFSD_MAY_LOCK)? " lock" : "",
|
|
(acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
|
|
inode->i_mode,
|
|
IS_IMMUTABLE(inode)? " immut" : "",
|
|
IS_APPEND(inode)? " append" : "",
|
|
__mnt_is_readonly(exp->ex_path.mnt)? " ro" : "");
|
|
dprintk(" owner %d/%d user %d/%d\n",
|
|
inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
|
|
#endif
|
|
|
|
/* Normally we reject any write/sattr etc access on a read-only file
|
|
* system. But if it is IRIX doing check on write-access for a
|
|
* device special file, we ignore rofs.
|
|
*/
|
|
if (!(acc & NFSD_MAY_LOCAL_ACCESS))
|
|
if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
|
|
if (exp_rdonly(rqstp, exp) ||
|
|
__mnt_is_readonly(exp->ex_path.mnt))
|
|
return nfserr_rofs;
|
|
if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
|
|
return nfserr_perm;
|
|
}
|
|
if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
|
|
return nfserr_perm;
|
|
|
|
if (acc & NFSD_MAY_LOCK) {
|
|
/* If we cannot rely on authentication in NLM requests,
|
|
* just allow locks, otherwise require read permission, or
|
|
* ownership
|
|
*/
|
|
if (exp->ex_flags & NFSEXP_NOAUTHNLM)
|
|
return 0;
|
|
else
|
|
acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE;
|
|
}
|
|
/*
|
|
* The file owner always gets access permission for accesses that
|
|
* would normally be checked at open time. This is to make
|
|
* file access work even when the client has done a fchmod(fd, 0).
|
|
*
|
|
* However, `cp foo bar' should fail nevertheless when bar is
|
|
* readonly. A sensible way to do this might be to reject all
|
|
* attempts to truncate a read-only file, because a creat() call
|
|
* always implies file truncation.
|
|
* ... but this isn't really fair. A process may reasonably call
|
|
* ftruncate on an open file descriptor on a file with perm 000.
|
|
* We must trust the client to do permission checking - using "ACCESS"
|
|
* with NFSv3.
|
|
*/
|
|
if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
|
|
uid_eq(inode->i_uid, current_fsuid()))
|
|
return 0;
|
|
|
|
/* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
|
|
err = inode_permission(&init_user_ns, inode,
|
|
acc & (MAY_READ | MAY_WRITE | MAY_EXEC));
|
|
|
|
/* Allow read access to binaries even when mode 111 */
|
|
if (err == -EACCES && S_ISREG(inode->i_mode) &&
|
|
(acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) ||
|
|
acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC)))
|
|
err = inode_permission(&init_user_ns, inode, MAY_EXEC);
|
|
|
|
return err? nfserrno(err) : 0;
|
|
}
|