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2418 lines
58 KiB
2418 lines
58 KiB
// 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 <[email protected]> |
|
* Zerocpy NFS support (C) 2002 Hirokazu Takahashi <[email protected]> |
|
*/ |
|
|
|
#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 "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 <[email protected]> |
|
*/ |
|
__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); |
|
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, 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 = 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 |
|
|
|
__be32 nfsd4_clone_file_range(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; |
|
loff_t cloned; |
|
__be32 ret = 0; |
|
|
|
down_write(&nf_dst->nf_rwsem); |
|
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 = commit_inode_metadata(file_inode(src)); |
|
if (status < 0) { |
|
nfsd_reset_boot_verifier(net_generic(nf_dst->nf_net, |
|
nfsd_net_id)); |
|
ret = nfserrno(status); |
|
} |
|
} |
|
out_err: |
|
up_write(&nf_dst->nf_rwsem); |
|
return ret; |
|
} |
|
|
|
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 }, |
|
|
|
#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; |
|
} |
|
#endif /* CONFIG_NFSD_V3 */ |
|
|
|
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); |
|
|
|
/* 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); |
|
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; |
|
|
|
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) |
|
err = __nfsd_open(rqstp, fhp, type, may_flags, filp); |
|
validate_process_creds(); |
|
return err; |
|
} |
|
|
|
__be32 |
|
nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, |
|
int may_flags, struct file **filp) |
|
{ |
|
__be32 err; |
|
|
|
validate_process_creds(); |
|
err = __nfsd_open(rqstp, fhp, type, 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; |
|
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 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 file *file = nf->nf_file; |
|
struct super_block *sb = file_inode(file)->i_sb; |
|
struct svc_export *exp; |
|
struct iov_iter iter; |
|
__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); |
|
if (flags & RWF_SYNC) { |
|
down_write(&nf->nf_rwsem); |
|
host_err = vfs_iter_write(file, &iter, &pos, flags); |
|
if (host_err < 0) |
|
nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp), |
|
nfsd_net_id)); |
|
up_write(&nf->nf_rwsem); |
|
} else { |
|
down_read(&nf->nf_rwsem); |
|
if (verf) |
|
nfsd_copy_boot_verifier(verf, |
|
net_generic(SVC_NET(rqstp), |
|
nfsd_net_id)); |
|
host_err = vfs_iter_write(file, &iter, &pos, flags); |
|
up_read(&nf->nf_rwsem); |
|
} |
|
if (host_err < 0) { |
|
nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp), |
|
nfsd_net_id)); |
|
goto out_nfserr; |
|
} |
|
*cnt = host_err; |
|
nfsd_stats_io_write_add(exp, *cnt); |
|
fsnotify_modify(file); |
|
|
|
if (stable && use_wgather) { |
|
host_err = wait_for_concurrent_writes(file); |
|
if (host_err < 0) |
|
nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp), |
|
nfsd_net_id)); |
|
} |
|
|
|
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; |
|
} |
|
|
|
#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, __be32 *verf) |
|
{ |
|
struct nfsd_file *nf; |
|
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_file_acquire(rqstp, fhp, |
|
NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &nf); |
|
if (err) |
|
goto out; |
|
if (EX_ISSYNC(fhp->fh_export)) { |
|
int err2; |
|
|
|
down_write(&nf->nf_rwsem); |
|
err2 = vfs_fsync_range(nf->nf_file, offset, end, 0); |
|
switch (err2) { |
|
case 0: |
|
nfsd_copy_boot_verifier(verf, net_generic(nf->nf_net, |
|
nfsd_net_id)); |
|
break; |
|
case -EINVAL: |
|
err = nfserr_notsupp; |
|
break; |
|
default: |
|
err = nfserrno(err2); |
|
nfsd_reset_boot_verifier(net_generic(nf->nf_net, |
|
nfsd_net_id)); |
|
} |
|
up_write(&nf->nf_rwsem); |
|
} else |
|
nfsd_copy_boot_verifier(verf, net_generic(nf->nf_net, |
|
nfsd_net_id)); |
|
|
|
nfsd_file_put(nf); |
|
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, (time64_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; |
|
|
|
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, 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; |
|
__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); |
|
} |
|
|
|
#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 = true; |
|
break; |
|
} |
|
fallthrough; |
|
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 = true; |
|
goto set_attr; |
|
} |
|
fallthrough; |
|
case NFS3_CREATE_GUARDED: |
|
err = nfserr_exist; |
|
} |
|
fh_drop_write(fhp); |
|
goto out; |
|
} |
|
|
|
if (!IS_POSIXACL(dirp)) |
|
iap->ia_mode &= ~current_umask(); |
|
|
|
host_err = vfs_create(&init_user_ns, dirp, dchild, iap->ia_mode, true); |
|
if (host_err < 0) { |
|
fh_drop_write(fhp); |
|
goto out_nfserr; |
|
} |
|
if (created) |
|
*created = true; |
|
|
|
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(&init_user_ns, 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, &init_user_ns, 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; |
|
} |
|
|
|
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; |
|
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; |
|
|
|
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) { |
|
fill_post_wcc(ffhp); |
|
fill_post_wcc(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; |
|
__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; |
|
} |
|
|
|
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); |
|
} |
|
|
|
if (!host_err) |
|
host_err = commit_metadata(fhp); |
|
dput(rdentry); |
|
|
|
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; |
|
}
|
|
|