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linux/fs/nfsd/vfs.c
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license 
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00

2091 lines
50 KiB
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// 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/slab.h>
#include <linux/uaccess.h>
#include <linux/exportfs.h>
#include <linux/writeback.h>
#include <linux/security.h>
#ifdef CONFIG_NFSD_V3
#include "xdr3.h"
#endif /* CONFIG_NFSD_V3 */
#ifdef CONFIG_NFSD_V4
#include "../internal.h"
#include "acl.h"
#include "idmap.h"
#endif /* CONFIG_NFSD_V4 */
#include "nfsd.h"
#include "vfs.h"
#include "trace.h"
#define NFSDDBG_FACILITY NFSDDBG_FILEOP
/*
* This is a cache of readahead params that help us choose the proper
* readahead strategy. Initially, we set all readahead parameters to 0
* and let the VFS handle things.
* If you increase the number of cached files very much, you'll need to
* add a hash table here.
*/
struct raparms {
struct raparms *p_next;
unsigned int p_count;
ino_t p_ino;
dev_t p_dev;
int p_set;
struct file_ra_state p_ra;
unsigned int p_hindex;
};
struct raparm_hbucket {
struct raparms *pb_head;
spinlock_t pb_lock;
} ____cacheline_aligned_in_smp;
#define RAPARM_HASH_BITS 4
#define RAPARM_HASH_SIZE (1<<RAPARM_HASH_BITS)
#define RAPARM_HASH_MASK (RAPARM_HASH_SIZE-1)
static struct raparm_hbucket raparm_hash[RAPARM_HASH_SIZE];
/*
* 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_metadata(struct svc_fh *fhp)
{
struct inode *inode = d_inode(fhp->fh_dentry);
const struct export_operations *export_ops = inode->i_sb->s_export_op;
if (!EX_ISSYNC(fhp->fh_export))
return 0;
if (export_ops->commit_metadata)
return export_ops->commit_metadata(inode);
return sync_inode_metadata(inode, 1);
}
/*
* 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);
int host_err;
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;
}
host_err = get_write_access(inode);
if (host_err)
goto out_nfserrno;
host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
if (host_err)
goto out_put_write_access;
return 0;
out_put_write_access:
put_write_access(inode);
out_nfserrno:
return nfserrno(host_err);
}
/*
* 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, time_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_ATIME | ATTR_MTIME | ATTR_SIZE))
accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
if (iap->ia_valid & ATTR_SIZE)
ftype = S_IFREG;
/* 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 = notify_change(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(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(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
__be32 nfsd4_clone_file_range(struct file *src, u64 src_pos, struct file *dst,
u64 dst_pos, u64 count)
{
return nfserrno(do_clone_file_range(src, src_pos, dst, dst_pos, count));
}
ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
u64 dst_pos, u64 count)
{
/*
* 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);
return vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
}
__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) */
#ifdef CONFIG_NFSD_V3
/*
* 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 },
{ 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 },
{ 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;
}
#endif /* CONFIG_NFSD_V3 */
static 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
*/
__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;
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;
err = fh_verify(rqstp, fhp, type, may_flags);
if (err)
goto out;
path.mnt = fhp->fh_export->ex_path.mnt;
path.dentry = fhp->fh_dentry;
inode = d_inode(path.dentry);
/* Disallow write access to files with the append-only bit set
* or any access when mandatory locking enabled
*/
err = nfserr_perm;
if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE))
goto out;
/*
* We must ignore files (but only files) which might have mandatory
* locks on them because there is no way to know if the accesser has
* the lock.
*/
if (S_ISREG((inode)->i_mode) && mandatory_lock(inode))
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, 0);
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:
validate_process_creds();
return err;
}
struct raparms *
nfsd_init_raparms(struct file *file)
{
struct inode *inode = file_inode(file);
dev_t dev = inode->i_sb->s_dev;
ino_t ino = inode->i_ino;
struct raparms *ra, **rap, **frap = NULL;
int depth = 0;
unsigned int hash;
struct raparm_hbucket *rab;
hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK;
rab = &raparm_hash[hash];
spin_lock(&rab->pb_lock);
for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) {
if (ra->p_ino == ino && ra->p_dev == dev)
goto found;
depth++;
if (ra->p_count == 0)
frap = rap;
}
depth = nfsdstats.ra_size;
if (!frap) {
spin_unlock(&rab->pb_lock);
return NULL;
}
rap = frap;
ra = *frap;
ra->p_dev = dev;
ra->p_ino = ino;
ra->p_set = 0;
ra->p_hindex = hash;
found:
if (rap != &rab->pb_head) {
*rap = ra->p_next;
ra->p_next = rab->pb_head;
rab->pb_head = ra;
}
ra->p_count++;
nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++;
spin_unlock(&rab->pb_lock);
if (ra->p_set)
file->f_ra = ra->p_ra;
return ra;
}
void nfsd_put_raparams(struct file *file, struct raparms *ra)
{
struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex];
spin_lock(&rab->pb_lock);
ra->p_ra = file->f_ra;
ra->p_set = 1;
ra->p_count--;
spin_unlock(&rab->pb_lock);
}
/*
* 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;
struct page **pp = rqstp->rq_next_page;
struct page *page = buf->page;
size_t size;
size = sd->len;
if (rqstp->rq_res.page_len == 0) {
get_page(page);
put_page(*rqstp->rq_next_page);
*(rqstp->rq_next_page++) = page;
rqstp->rq_res.page_base = buf->offset;
rqstp->rq_res.page_len = size;
} else if (page != pp[-1]) {
get_page(page);
if (*rqstp->rq_next_page)
put_page(*rqstp->rq_next_page);
*(rqstp->rq_next_page++) = page;
rqstp->rq_res.page_len += size;
} else
rqstp->rq_res.page_len += size;
return size;
}
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 __be32
nfsd_finish_read(struct file *file, unsigned long *count, int host_err)
{
if (host_err >= 0) {
nfsdstats.io_read += host_err;
*count = host_err;
fsnotify_access(file);
return 0;
} else
return nfserrno(host_err);
}
__be32 nfsd_splice_read(struct svc_rqst *rqstp,
struct file *file, loff_t offset, unsigned long *count)
{
struct splice_desc sd = {
.len = 0,
.total_len = *count,
.pos = offset,
.u.data = rqstp,
};
int host_err;
rqstp->rq_next_page = rqstp->rq_respages + 1;
host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
return nfsd_finish_read(file, count, host_err);
}
__be32 nfsd_readv(struct file *file, loff_t offset, struct kvec *vec, int vlen,
unsigned long *count)
{
struct iov_iter iter;
int host_err;
iov_iter_kvec(&iter, READ | ITER_KVEC, vec, vlen, *count);
host_err = vfs_iter_read(file, &iter, &offset, 0);
return nfsd_finish_read(file, count, 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 file *file,
loff_t offset, struct kvec *vec, int vlen,
unsigned long *cnt, int stable)
{
struct svc_export *exp;
struct iov_iter iter;
__be32 err = 0;
int host_err;
int use_wgather;
loff_t pos = offset;
unsigned int pflags = current->flags;
rwf_t flags = 0;
if (test_bit(RQ_LOCAL, &rqstp->rq_flags))
/*
* We want less throttling in balance_dirty_pages()
* and shrink_inactive_list() 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_LESS_THROTTLE;
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 | ITER_KVEC, vec, vlen, *cnt);
host_err = vfs_iter_write(file, &iter, &pos, flags);
if (host_err < 0)
goto out_nfserr;
*cnt = host_err;
nfsdstats.io_write += host_err;
fsnotify_modify(file);
if (stable && use_wgather)
host_err = wait_for_concurrent_writes(file);
out_nfserr:
dprintk("nfsd: write complete host_err=%d\n", host_err);
if (host_err >= 0)
err = 0;
else
err = nfserrno(host_err);
if (test_bit(RQ_LOCAL, &rqstp->rq_flags))
current_restore_flags(pflags, PF_LESS_THROTTLE);
return err;
}
/*
* 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)
{
struct file *file;
struct raparms *ra;
__be32 err;
trace_read_start(rqstp, fhp, offset, vlen);
err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file);
if (err)
return err;
ra = nfsd_init_raparms(file);
trace_read_opened(rqstp, fhp, offset, vlen);
if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags))
err = nfsd_splice_read(rqstp, file, offset, count);
else
err = nfsd_readv(file, offset, vec, vlen, count);
trace_read_io_done(rqstp, fhp, offset, vlen);
if (ra)
nfsd_put_raparams(file, ra);
fput(file);
trace_read_done(rqstp, fhp, offset, vlen);
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)
{
struct file *file = NULL;
__be32 err = 0;
trace_write_start(rqstp, fhp, offset, vlen);
err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file);
if (err)
goto out;
trace_write_opened(rqstp, fhp, offset, vlen);
err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, stable);
trace_write_io_done(rqstp, fhp, offset, vlen);
fput(file);
out:
trace_write_done(rqstp, fhp, offset, vlen);
return err;
}
#ifdef CONFIG_NFSD_V3
/*
* Commit all pending writes to stable storage.
*
* Note: we only guarantee that data that lies within the range specified
* by the 'offset' and 'count' parameters will be synced.
*
* 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.
*/
__be32
nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
loff_t offset, unsigned long count)
{
struct file *file;
loff_t end = LLONG_MAX;
__be32 err = nfserr_inval;
if (offset < 0)
goto out;
if (count != 0) {
end = offset + (loff_t)count - 1;
if (end < offset)
goto out;
}
err = nfsd_open(rqstp, fhp, S_IFREG,
NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &file);
if (err)
goto out;
if (EX_ISSYNC(fhp->fh_export)) {
int err2 = vfs_fsync_range(file, offset, end, 0);
if (err2 != -EINVAL)
err = nfserrno(err2);
else
err = nfserr_notsupp;
}
fput(file);
out:
return err;
}
#endif /* CONFIG_NFSD_V3 */
static __be32
nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
struct iattr *iap)
{
/*
* Mode has already been set earlier in create:
*/
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);
if (iap->ia_valid)
return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
/* Callers expect file metadata to be committed here */
return nfserrno(commit_metadata(resfhp));
}
/* 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;
__be32 err2;
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;
err = 0;
host_err = 0;
switch (type) {
case S_IFREG:
host_err = vfs_create(dirp, dchild, iap->ia_mode, true);
if (!host_err)
nfsd_check_ignore_resizing(iap);
break;
case S_IFDIR:
host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
break;
case S_IFCHR:
case S_IFBLK:
case S_IFIFO:
case S_IFSOCK:
host_err = vfs_mknod(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, resfhp, iap);
/*
* nfsd_create_setattr already committed the child. Transactional
* filesystems had a chance to commit changes for both parent and
* child simultaneously making the following commit_metadata a
* noop.
*/
err2 = nfserrno(commit_metadata(fhp));
if (err2)
err = err2;
/*
* Update the file handle to get the new inode info.
*/
if (!err)
err = fh_update(resfhp);
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;
struct inode *dirp;
__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;
dirp = d_inode(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);
}
#ifdef CONFIG_NFSD_V3
/*
* NFSv3 and NFSv4 version of nfsd_create
*/
__be32
do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
char *fname, int flen, struct iattr *iap,
struct svc_fh *resfhp, int createmode, u32 *verifier,
bool *truncp, bool *created)
{
struct dentry *dentry, *dchild = NULL;
struct inode *dirp;
__be32 err;
int host_err;
__u32 v_mtime=0, v_atime=0;
err = nfserr_perm;
if (!flen)
goto out;
err = nfserr_exist;
if (isdotent(fname, flen))
goto out;
if (!(iap->ia_valid & ATTR_MODE))
iap->ia_mode = 0;
err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
if (err)
goto out;
dentry = fhp->fh_dentry;
dirp = d_inode(dentry);
host_err = fh_want_write(fhp);
if (host_err)
goto out_nfserr;
fh_lock_nested(fhp, I_MUTEX_PARENT);
/*
* Compose the response file handle.
*/
dchild = lookup_one_len(fname, dentry, flen);
host_err = PTR_ERR(dchild);
if (IS_ERR(dchild))
goto out_nfserr;
/* If file doesn't exist, check for permissions to create one */
if (d_really_is_negative(dchild)) {
err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
if (err)
goto out;
}
err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
if (err)
goto out;
if (nfsd_create_is_exclusive(createmode)) {
/* solaris7 gets confused (bugid 4218508) if these have
* the high bit set, so just clear the high bits. If this is
* ever changed to use different attrs for storing the
* verifier, then do_open_lookup() will also need to be fixed
* accordingly.
*/
v_mtime = verifier[0]&0x7fffffff;
v_atime = verifier[1]&0x7fffffff;
}
if (d_really_is_positive(dchild)) {
err = 0;
switch (createmode) {
case NFS3_CREATE_UNCHECKED:
if (! d_is_reg(dchild))
goto out;
else if (truncp) {
/* in nfsv4, we need to treat this case a little
* differently. we don't want to truncate the
* file now; this would be wrong if the OPEN
* fails for some other reason. furthermore,
* if the size is nonzero, we should ignore it
* according to spec!
*/
*truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
}
else {
iap->ia_valid &= ATTR_SIZE;
goto set_attr;
}
break;
case NFS3_CREATE_EXCLUSIVE:
if ( d_inode(dchild)->i_mtime.tv_sec == v_mtime
&& d_inode(dchild)->i_atime.tv_sec == v_atime
&& d_inode(dchild)->i_size == 0 ) {
if (created)
*created = 1;
break;
}
case NFS4_CREATE_EXCLUSIVE4_1:
if ( d_inode(dchild)->i_mtime.tv_sec == v_mtime
&& d_inode(dchild)->i_atime.tv_sec == v_atime
&& d_inode(dchild)->i_size == 0 ) {
if (created)
*created = 1;
goto set_attr;
}
/* fallthru */
case NFS3_CREATE_GUARDED:
err = nfserr_exist;
}
fh_drop_write(fhp);
goto out;
}
host_err = vfs_create(dirp, dchild, iap->ia_mode, true);
if (host_err < 0) {
fh_drop_write(fhp);
goto out_nfserr;
}
if (created)
*created = 1;
nfsd_check_ignore_resizing(iap);
if (nfsd_create_is_exclusive(createmode)) {
/* Cram the verifier into atime/mtime */
iap->ia_valid = ATTR_MTIME|ATTR_ATIME
| ATTR_MTIME_SET|ATTR_ATIME_SET;
/* XXX someone who knows this better please fix it for nsec */
iap->ia_mtime.tv_sec = v_mtime;
iap->ia_atime.tv_sec = v_atime;
iap->ia_mtime.tv_nsec = 0;
iap->ia_atime.tv_nsec = 0;
}
set_attr:
err = nfsd_create_setattr(rqstp, resfhp, iap);
/*
* nfsd_create_setattr already committed the child
* (and possibly also the parent).
*/
if (!err)
err = nfserrno(commit_metadata(fhp));
/*
* Update the filehandle to get the new inode info.
*/
if (!err)
err = fh_update(resfhp);
out:
fh_unlock(fhp);
if (dchild && !IS_ERR(dchild))
dput(dchild);
fh_drop_write(fhp);
return err;
out_nfserr:
err = nfserrno(host_err);
goto out;
}
#endif /* CONFIG_NFSD_V3 */
/*
* 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(d_inode(dentry), dnew, path);
err = nfserrno(host_err);
if (!err)
err = nfserrno(commit_metadata(fhp));
fh_unlock(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, dirp, dnew, NULL);
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;
}
/*
* 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;
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;
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;
fill_pre_wcc(ffhp);
fill_pre_wcc(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;
host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0);
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.
*/
fill_post_wcc(ffhp);
fill_post_wcc(tfhp);
unlock_rename(tdentry, fdentry);
ffhp->fh_locked = tfhp->fh_locked = false;
fh_drop_write(ffhp);
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;
__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_nfserr;
if (d_really_is_negative(rdentry)) {
dput(rdentry);
err = nfserr_noent;
goto out;
}
if (!type)
type = d_inode(rdentry)->i_mode & S_IFMT;
if (type != S_IFDIR)
host_err = vfs_unlink(dirp, rdentry, NULL);
else
host_err = vfs_rmdir(dirp, rdentry);
if (!host_err)
host_err = commit_metadata(fhp);
dput(rdentry);
out_nfserr:
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, 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;
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, 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;
}
/*
* 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(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(inode, MAY_EXEC);
return err? nfserrno(err) : 0;
}
void
nfsd_racache_shutdown(void)
{
struct raparms *raparm, *last_raparm;
unsigned int i;
dprintk("nfsd: freeing readahead buffers.\n");
for (i = 0; i < RAPARM_HASH_SIZE; i++) {
raparm = raparm_hash[i].pb_head;
while(raparm) {
last_raparm = raparm;
raparm = raparm->p_next;
kfree(last_raparm);
}
raparm_hash[i].pb_head = NULL;
}
}
/*
* Initialize readahead param cache
*/
int
nfsd_racache_init(int cache_size)
{
int i;
int j = 0;
int nperbucket;
struct raparms **raparm = NULL;
if (raparm_hash[0].pb_head)
return 0;
nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE);
nperbucket = max(2, nperbucket);
cache_size = nperbucket * RAPARM_HASH_SIZE;
dprintk("nfsd: allocating %d readahead buffers.\n", cache_size);
for (i = 0; i < RAPARM_HASH_SIZE; i++) {
spin_lock_init(&raparm_hash[i].pb_lock);
raparm = &raparm_hash[i].pb_head;
for (j = 0; j < nperbucket; j++) {
*raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL);
if (!*raparm)
goto out_nomem;
raparm = &(*raparm)->p_next;
}
*raparm = NULL;
}
nfsdstats.ra_size = cache_size;
return 0;
out_nomem:
dprintk("nfsd: kmalloc failed, freeing readahead buffers\n");
nfsd_racache_shutdown();
return -ENOMEM;
}
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