linux/net/9p/conv.c
Eric Van Hensbergen 16ec470012 9p: fix put_data error handling
Abhishek Kulkarni pointed out an inconsistency in the way
errors are returned from p9_put_data.  On deeper exploration it
seems the error handling for this path was completely wrong.
This patch adds checks for allocation problems and propagates
errors correctly.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-09-24 16:22:22 -05:00

1055 lines
24 KiB
C

/*
* net/9p/conv.c
*
* 9P protocol conversion functions
*
* Copyright (C) 2004, 2005 by Latchesar Ionkov <lucho@ionkov.net>
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to:
* Free Software Foundation
* 51 Franklin Street, Fifth Floor
* Boston, MA 02111-1301 USA
*
*/
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/idr.h>
#include <linux/uaccess.h>
#include <net/9p/9p.h>
/*
* Buffer to help with string parsing
*/
struct cbuf {
unsigned char *sp;
unsigned char *p;
unsigned char *ep;
};
static inline void buf_init(struct cbuf *buf, void *data, int datalen)
{
buf->sp = buf->p = data;
buf->ep = data + datalen;
}
static inline int buf_check_overflow(struct cbuf *buf)
{
return buf->p > buf->ep;
}
static int buf_check_size(struct cbuf *buf, int len)
{
if (buf->p + len > buf->ep) {
if (buf->p < buf->ep) {
P9_EPRINTK(KERN_ERR,
"buffer overflow: want %d has %d\n", len,
(int)(buf->ep - buf->p));
dump_stack();
buf->p = buf->ep + 1;
}
return 0;
}
return 1;
}
static void *buf_alloc(struct cbuf *buf, int len)
{
void *ret = NULL;
if (buf_check_size(buf, len)) {
ret = buf->p;
buf->p += len;
}
return ret;
}
static void buf_put_int8(struct cbuf *buf, u8 val)
{
if (buf_check_size(buf, 1)) {
buf->p[0] = val;
buf->p++;
}
}
static void buf_put_int16(struct cbuf *buf, u16 val)
{
if (buf_check_size(buf, 2)) {
*(__le16 *) buf->p = cpu_to_le16(val);
buf->p += 2;
}
}
static void buf_put_int32(struct cbuf *buf, u32 val)
{
if (buf_check_size(buf, 4)) {
*(__le32 *)buf->p = cpu_to_le32(val);
buf->p += 4;
}
}
static void buf_put_int64(struct cbuf *buf, u64 val)
{
if (buf_check_size(buf, 8)) {
*(__le64 *)buf->p = cpu_to_le64(val);
buf->p += 8;
}
}
static char *buf_put_stringn(struct cbuf *buf, const char *s, u16 slen)
{
char *ret;
ret = NULL;
if (buf_check_size(buf, slen + 2)) {
buf_put_int16(buf, slen);
ret = buf->p;
memcpy(buf->p, s, slen);
buf->p += slen;
}
return ret;
}
static u8 buf_get_int8(struct cbuf *buf)
{
u8 ret = 0;
if (buf_check_size(buf, 1)) {
ret = buf->p[0];
buf->p++;
}
return ret;
}
static u16 buf_get_int16(struct cbuf *buf)
{
u16 ret = 0;
if (buf_check_size(buf, 2)) {
ret = le16_to_cpu(*(__le16 *)buf->p);
buf->p += 2;
}
return ret;
}
static u32 buf_get_int32(struct cbuf *buf)
{
u32 ret = 0;
if (buf_check_size(buf, 4)) {
ret = le32_to_cpu(*(__le32 *)buf->p);
buf->p += 4;
}
return ret;
}
static u64 buf_get_int64(struct cbuf *buf)
{
u64 ret = 0;
if (buf_check_size(buf, 8)) {
ret = le64_to_cpu(*(__le64 *)buf->p);
buf->p += 8;
}
return ret;
}
static void buf_get_str(struct cbuf *buf, struct p9_str *vstr)
{
vstr->len = buf_get_int16(buf);
if (!buf_check_overflow(buf) && buf_check_size(buf, vstr->len)) {
vstr->str = buf->p;
buf->p += vstr->len;
} else {
vstr->len = 0;
vstr->str = NULL;
}
}
static void buf_get_qid(struct cbuf *bufp, struct p9_qid *qid)
{
qid->type = buf_get_int8(bufp);
qid->version = buf_get_int32(bufp);
qid->path = buf_get_int64(bufp);
}
/**
* p9_size_wstat - calculate the size of a variable length stat struct
* @wstat: metadata (stat) structure
* @dotu: non-zero if 9P2000.u
*
*/
static int p9_size_wstat(struct p9_wstat *wstat, int dotu)
{
int size = 0;
if (wstat == NULL) {
P9_EPRINTK(KERN_ERR, "p9_size_stat: got a NULL stat pointer\n");
return 0;
}
size = /* 2 + *//* size[2] */
2 + /* type[2] */
4 + /* dev[4] */
1 + /* qid.type[1] */
4 + /* qid.vers[4] */
8 + /* qid.path[8] */
4 + /* mode[4] */
4 + /* atime[4] */
4 + /* mtime[4] */
8 + /* length[8] */
8; /* minimum sum of string lengths */
if (wstat->name)
size += strlen(wstat->name);
if (wstat->uid)
size += strlen(wstat->uid);
if (wstat->gid)
size += strlen(wstat->gid);
if (wstat->muid)
size += strlen(wstat->muid);
if (dotu) {
size += 4 + /* n_uid[4] */
4 + /* n_gid[4] */
4 + /* n_muid[4] */
2; /* string length of extension[4] */
if (wstat->extension)
size += strlen(wstat->extension);
}
return size;
}
/**
* buf_get_stat - safely decode a recieved metadata (stat) structure
* @bufp: buffer to deserialize
* @stat: metadata (stat) structure
* @dotu: non-zero if 9P2000.u
*
*/
static void
buf_get_stat(struct cbuf *bufp, struct p9_stat *stat, int dotu)
{
stat->size = buf_get_int16(bufp);
stat->type = buf_get_int16(bufp);
stat->dev = buf_get_int32(bufp);
stat->qid.type = buf_get_int8(bufp);
stat->qid.version = buf_get_int32(bufp);
stat->qid.path = buf_get_int64(bufp);
stat->mode = buf_get_int32(bufp);
stat->atime = buf_get_int32(bufp);
stat->mtime = buf_get_int32(bufp);
stat->length = buf_get_int64(bufp);
buf_get_str(bufp, &stat->name);
buf_get_str(bufp, &stat->uid);
buf_get_str(bufp, &stat->gid);
buf_get_str(bufp, &stat->muid);
if (dotu) {
buf_get_str(bufp, &stat->extension);
stat->n_uid = buf_get_int32(bufp);
stat->n_gid = buf_get_int32(bufp);
stat->n_muid = buf_get_int32(bufp);
}
}
/**
* p9_deserialize_stat - decode a received metadata structure
* @buf: buffer to deserialize
* @buflen: length of received buffer
* @stat: metadata structure to decode into
* @dotu: non-zero if 9P2000.u
*
* Note: stat will point to the buf region.
*/
int
p9_deserialize_stat(void *buf, u32 buflen, struct p9_stat *stat,
int dotu)
{
struct cbuf buffer;
struct cbuf *bufp = &buffer;
unsigned char *p;
buf_init(bufp, buf, buflen);
p = bufp->p;
buf_get_stat(bufp, stat, dotu);
if (buf_check_overflow(bufp))
return 0;
else
return bufp->p - p;
}
EXPORT_SYMBOL(p9_deserialize_stat);
/**
* deserialize_fcall - unmarshal a response
* @buf: recieved buffer
* @buflen: length of received buffer
* @rcall: fcall structure to populate
* @rcalllen: length of fcall structure to populate
* @dotu: non-zero if 9P2000.u
*
*/
int
p9_deserialize_fcall(void *buf, u32 buflen, struct p9_fcall *rcall,
int dotu)
{
struct cbuf buffer;
struct cbuf *bufp = &buffer;
int i = 0;
buf_init(bufp, buf, buflen);
rcall->size = buf_get_int32(bufp);
rcall->id = buf_get_int8(bufp);
rcall->tag = buf_get_int16(bufp);
P9_DPRINTK(P9_DEBUG_CONV, "size %d id %d tag %d\n", rcall->size,
rcall->id, rcall->tag);
switch (rcall->id) {
default:
P9_EPRINTK(KERN_ERR, "unknown message type: %d\n", rcall->id);
return -EPROTO;
case P9_RVERSION:
rcall->params.rversion.msize = buf_get_int32(bufp);
buf_get_str(bufp, &rcall->params.rversion.version);
break;
case P9_RFLUSH:
break;
case P9_RATTACH:
rcall->params.rattach.qid.type = buf_get_int8(bufp);
rcall->params.rattach.qid.version = buf_get_int32(bufp);
rcall->params.rattach.qid.path = buf_get_int64(bufp);
break;
case P9_RWALK:
rcall->params.rwalk.nwqid = buf_get_int16(bufp);
if (rcall->params.rwalk.nwqid > P9_MAXWELEM) {
P9_EPRINTK(KERN_ERR,
"Rwalk with more than %d qids: %d\n",
P9_MAXWELEM, rcall->params.rwalk.nwqid);
return -EPROTO;
}
for (i = 0; i < rcall->params.rwalk.nwqid; i++)
buf_get_qid(bufp, &rcall->params.rwalk.wqids[i]);
break;
case P9_ROPEN:
buf_get_qid(bufp, &rcall->params.ropen.qid);
rcall->params.ropen.iounit = buf_get_int32(bufp);
break;
case P9_RCREATE:
buf_get_qid(bufp, &rcall->params.rcreate.qid);
rcall->params.rcreate.iounit = buf_get_int32(bufp);
break;
case P9_RREAD:
rcall->params.rread.count = buf_get_int32(bufp);
rcall->params.rread.data = bufp->p;
buf_check_size(bufp, rcall->params.rread.count);
break;
case P9_RWRITE:
rcall->params.rwrite.count = buf_get_int32(bufp);
break;
case P9_RCLUNK:
break;
case P9_RREMOVE:
break;
case P9_RSTAT:
buf_get_int16(bufp);
buf_get_stat(bufp, &rcall->params.rstat.stat, dotu);
break;
case P9_RWSTAT:
break;
case P9_RERROR:
buf_get_str(bufp, &rcall->params.rerror.error);
if (dotu)
rcall->params.rerror.errno = buf_get_int16(bufp);
break;
}
if (buf_check_overflow(bufp)) {
P9_DPRINTK(P9_DEBUG_ERROR, "buffer overflow\n");
return -EIO;
}
return bufp->p - bufp->sp;
}
EXPORT_SYMBOL(p9_deserialize_fcall);
static inline void p9_put_int8(struct cbuf *bufp, u8 val, u8 * p)
{
*p = val;
buf_put_int8(bufp, val);
}
static inline void p9_put_int16(struct cbuf *bufp, u16 val, u16 * p)
{
*p = val;
buf_put_int16(bufp, val);
}
static inline void p9_put_int32(struct cbuf *bufp, u32 val, u32 * p)
{
*p = val;
buf_put_int32(bufp, val);
}
static inline void p9_put_int64(struct cbuf *bufp, u64 val, u64 * p)
{
*p = val;
buf_put_int64(bufp, val);
}
static void
p9_put_str(struct cbuf *bufp, char *data, struct p9_str *str)
{
int len;
char *s;
if (data)
len = strlen(data);
else
len = 0;
s = buf_put_stringn(bufp, data, len);
if (str) {
str->len = len;
str->str = s;
}
}
static int
p9_put_data(struct cbuf *bufp, const char *data, int count,
unsigned char **pdata)
{
*pdata = buf_alloc(bufp, count);
if (*pdata == NULL)
return -ENOMEM;
memmove(*pdata, data, count);
return 0;
}
static int
p9_put_user_data(struct cbuf *bufp, const char __user *data, int count,
unsigned char **pdata)
{
*pdata = buf_alloc(bufp, count);
if (*pdata == NULL)
return -ENOMEM;
return copy_from_user(*pdata, data, count);
}
static void
p9_put_wstat(struct cbuf *bufp, struct p9_wstat *wstat,
struct p9_stat *stat, int statsz, int dotu)
{
p9_put_int16(bufp, statsz, &stat->size);
p9_put_int16(bufp, wstat->type, &stat->type);
p9_put_int32(bufp, wstat->dev, &stat->dev);
p9_put_int8(bufp, wstat->qid.type, &stat->qid.type);
p9_put_int32(bufp, wstat->qid.version, &stat->qid.version);
p9_put_int64(bufp, wstat->qid.path, &stat->qid.path);
p9_put_int32(bufp, wstat->mode, &stat->mode);
p9_put_int32(bufp, wstat->atime, &stat->atime);
p9_put_int32(bufp, wstat->mtime, &stat->mtime);
p9_put_int64(bufp, wstat->length, &stat->length);
p9_put_str(bufp, wstat->name, &stat->name);
p9_put_str(bufp, wstat->uid, &stat->uid);
p9_put_str(bufp, wstat->gid, &stat->gid);
p9_put_str(bufp, wstat->muid, &stat->muid);
if (dotu) {
p9_put_str(bufp, wstat->extension, &stat->extension);
p9_put_int32(bufp, wstat->n_uid, &stat->n_uid);
p9_put_int32(bufp, wstat->n_gid, &stat->n_gid);
p9_put_int32(bufp, wstat->n_muid, &stat->n_muid);
}
}
static struct p9_fcall *
p9_create_common(struct cbuf *bufp, u32 size, u8 id)
{
struct p9_fcall *fc;
size += 4 + 1 + 2; /* size[4] id[1] tag[2] */
fc = kmalloc(sizeof(struct p9_fcall) + size, GFP_KERNEL);
if (!fc)
return ERR_PTR(-ENOMEM);
fc->sdata = (char *)fc + sizeof(*fc);
buf_init(bufp, (char *)fc->sdata, size);
p9_put_int32(bufp, size, &fc->size);
p9_put_int8(bufp, id, &fc->id);
p9_put_int16(bufp, P9_NOTAG, &fc->tag);
return fc;
}
/**
* p9_set_tag - set the tag field of an &p9_fcall structure
* @fc: fcall structure to set tag within
* @tag: tag id to set
*/
void p9_set_tag(struct p9_fcall *fc, u16 tag)
{
fc->tag = tag;
*(__le16 *) (fc->sdata + 5) = cpu_to_le16(tag);
}
EXPORT_SYMBOL(p9_set_tag);
/**
* p9_create_tversion - allocates and creates a T_VERSION request
* @msize: requested maximum data size
* @version: version string to negotiate
*
*/
struct p9_fcall *p9_create_tversion(u32 msize, char *version)
{
int size;
struct p9_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 4 + 2 + strlen(version); /* msize[4] version[s] */
fc = p9_create_common(bufp, size, P9_TVERSION);
if (IS_ERR(fc))
goto error;
p9_put_int32(bufp, msize, &fc->params.tversion.msize);
p9_put_str(bufp, version, &fc->params.tversion.version);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
EXPORT_SYMBOL(p9_create_tversion);
/**
* p9_create_tauth - allocates and creates a T_AUTH request
* @afid: handle to use for authentication protocol
* @uname: user name attempting to authenticate
* @aname: mount specifier for remote server
* @n_uname: numeric id for user attempting to authneticate
* @dotu: 9P2000.u extension flag
*
*/
struct p9_fcall *p9_create_tauth(u32 afid, char *uname, char *aname,
u32 n_uname, int dotu)
{
int size;
struct p9_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
/* afid[4] uname[s] aname[s] */
size = 4 + 2 + 2;
if (uname)
size += strlen(uname);
if (aname)
size += strlen(aname);
if (dotu)
size += 4; /* n_uname */
fc = p9_create_common(bufp, size, P9_TAUTH);
if (IS_ERR(fc))
goto error;
p9_put_int32(bufp, afid, &fc->params.tauth.afid);
p9_put_str(bufp, uname, &fc->params.tauth.uname);
p9_put_str(bufp, aname, &fc->params.tauth.aname);
if (dotu)
p9_put_int32(bufp, n_uname, &fc->params.tauth.n_uname);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
EXPORT_SYMBOL(p9_create_tauth);
/**
* p9_create_tattach - allocates and creates a T_ATTACH request
* @fid: handle to use for the new mount point
* @afid: handle to use for authentication protocol
* @uname: user name attempting to attach
* @aname: mount specifier for remote server
* @n_uname: numeric id for user attempting to attach
* @n_uname: numeric id for user attempting to attach
* @dotu: 9P2000.u extension flag
*
*/
struct p9_fcall *
p9_create_tattach(u32 fid, u32 afid, char *uname, char *aname,
u32 n_uname, int dotu)
{
int size;
struct p9_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
/* fid[4] afid[4] uname[s] aname[s] */
size = 4 + 4 + 2 + 2;
if (uname)
size += strlen(uname);
if (aname)
size += strlen(aname);
if (dotu)
size += 4; /* n_uname */
fc = p9_create_common(bufp, size, P9_TATTACH);
if (IS_ERR(fc))
goto error;
p9_put_int32(bufp, fid, &fc->params.tattach.fid);
p9_put_int32(bufp, afid, &fc->params.tattach.afid);
p9_put_str(bufp, uname, &fc->params.tattach.uname);
p9_put_str(bufp, aname, &fc->params.tattach.aname);
if (dotu)
p9_put_int32(bufp, n_uname, &fc->params.tattach.n_uname);
error:
return fc;
}
EXPORT_SYMBOL(p9_create_tattach);
/**
* p9_create_tflush - allocates and creates a T_FLUSH request
* @oldtag: tag id for the transaction we are attempting to cancel
*
*/
struct p9_fcall *p9_create_tflush(u16 oldtag)
{
int size;
struct p9_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 2; /* oldtag[2] */
fc = p9_create_common(bufp, size, P9_TFLUSH);
if (IS_ERR(fc))
goto error;
p9_put_int16(bufp, oldtag, &fc->params.tflush.oldtag);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
EXPORT_SYMBOL(p9_create_tflush);
/**
* p9_create_twalk - allocates and creates a T_FLUSH request
* @fid: handle we are traversing from
* @newfid: a new handle for this transaction
* @nwname: number of path elements to traverse
* @wnames: array of path elements
*
*/
struct p9_fcall *p9_create_twalk(u32 fid, u32 newfid, u16 nwname,
char **wnames)
{
int i, size;
struct p9_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
if (nwname > P9_MAXWELEM) {
P9_DPRINTK(P9_DEBUG_ERROR, "nwname > %d\n", P9_MAXWELEM);
return NULL;
}
size = 4 + 4 + 2; /* fid[4] newfid[4] nwname[2] ... */
for (i = 0; i < nwname; i++) {
size += 2 + strlen(wnames[i]); /* wname[s] */
}
fc = p9_create_common(bufp, size, P9_TWALK);
if (IS_ERR(fc))
goto error;
p9_put_int32(bufp, fid, &fc->params.twalk.fid);
p9_put_int32(bufp, newfid, &fc->params.twalk.newfid);
p9_put_int16(bufp, nwname, &fc->params.twalk.nwname);
for (i = 0; i < nwname; i++) {
p9_put_str(bufp, wnames[i], &fc->params.twalk.wnames[i]);
}
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
EXPORT_SYMBOL(p9_create_twalk);
/**
* p9_create_topen - allocates and creates a T_OPEN request
* @fid: handle we are trying to open
* @mode: what mode we are trying to open the file in
*
*/
struct p9_fcall *p9_create_topen(u32 fid, u8 mode)
{
int size;
struct p9_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 4 + 1; /* fid[4] mode[1] */
fc = p9_create_common(bufp, size, P9_TOPEN);
if (IS_ERR(fc))
goto error;
p9_put_int32(bufp, fid, &fc->params.topen.fid);
p9_put_int8(bufp, mode, &fc->params.topen.mode);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
EXPORT_SYMBOL(p9_create_topen);
/**
* p9_create_tcreate - allocates and creates a T_CREATE request
* @fid: handle of directory we are trying to create in
* @name: name of the file we are trying to create
* @perm: permissions for the file we are trying to create
* @mode: what mode we are trying to open the file in
* @extension: 9p2000.u extension string (for special files)
* @dotu: 9p2000.u enabled flag
*
* Note: Plan 9 create semantics include opening the resulting file
* which is why mode is included.
*/
struct p9_fcall *p9_create_tcreate(u32 fid, char *name, u32 perm, u8 mode,
char *extension, int dotu)
{
int size;
struct p9_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
/* fid[4] name[s] perm[4] mode[1] */
size = 4 + 2 + strlen(name) + 4 + 1;
if (dotu) {
size += 2 + /* extension[s] */
(extension == NULL ? 0 : strlen(extension));
}
fc = p9_create_common(bufp, size, P9_TCREATE);
if (IS_ERR(fc))
goto error;
p9_put_int32(bufp, fid, &fc->params.tcreate.fid);
p9_put_str(bufp, name, &fc->params.tcreate.name);
p9_put_int32(bufp, perm, &fc->params.tcreate.perm);
p9_put_int8(bufp, mode, &fc->params.tcreate.mode);
if (dotu)
p9_put_str(bufp, extension, &fc->params.tcreate.extension);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
EXPORT_SYMBOL(p9_create_tcreate);
/**
* p9_create_tread - allocates and creates a T_READ request
* @fid: handle of the file we are trying to read
* @offset: offset to start reading from
* @count: how many bytes to read
*/
struct p9_fcall *p9_create_tread(u32 fid, u64 offset, u32 count)
{
int size;
struct p9_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 4 + 8 + 4; /* fid[4] offset[8] count[4] */
fc = p9_create_common(bufp, size, P9_TREAD);
if (IS_ERR(fc))
goto error;
p9_put_int32(bufp, fid, &fc->params.tread.fid);
p9_put_int64(bufp, offset, &fc->params.tread.offset);
p9_put_int32(bufp, count, &fc->params.tread.count);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
EXPORT_SYMBOL(p9_create_tread);
/**
* p9_create_twrite - allocates and creates a T_WRITE request from the kernel
* @fid: handle of the file we are trying to write
* @offset: offset to start writing at
* @count: how many bytes to write
* @data: data to write
*
* This function will create a requst with data buffers from the kernel
* such as the page cache.
*/
struct p9_fcall *p9_create_twrite(u32 fid, u64 offset, u32 count,
const char *data)
{
int size, err;
struct p9_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
/* fid[4] offset[8] count[4] data[count] */
size = 4 + 8 + 4 + count;
fc = p9_create_common(bufp, size, P9_TWRITE);
if (IS_ERR(fc))
goto error;
p9_put_int32(bufp, fid, &fc->params.twrite.fid);
p9_put_int64(bufp, offset, &fc->params.twrite.offset);
p9_put_int32(bufp, count, &fc->params.twrite.count);
err = p9_put_data(bufp, data, count, &fc->params.twrite.data);
if (err) {
kfree(fc);
fc = ERR_PTR(err);
goto error;
}
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
EXPORT_SYMBOL(p9_create_twrite);
/**
* p9_create_twrite_u - allocates and creates a T_WRITE request from userspace
* @fid: handle of the file we are trying to write
* @offset: offset to start writing at
* @count: how many bytes to write
* @data: data to write
*
* This function will create a request with data buffers from userspace
*/
struct p9_fcall *p9_create_twrite_u(u32 fid, u64 offset, u32 count,
const char __user *data)
{
int size, err;
struct p9_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
/* fid[4] offset[8] count[4] data[count] */
size = 4 + 8 + 4 + count;
fc = p9_create_common(bufp, size, P9_TWRITE);
if (IS_ERR(fc))
goto error;
p9_put_int32(bufp, fid, &fc->params.twrite.fid);
p9_put_int64(bufp, offset, &fc->params.twrite.offset);
p9_put_int32(bufp, count, &fc->params.twrite.count);
err = p9_put_user_data(bufp, data, count, &fc->params.twrite.data);
if (err) {
kfree(fc);
fc = ERR_PTR(err);
goto error;
}
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
EXPORT_SYMBOL(p9_create_twrite_u);
/**
* p9_create_tclunk - allocate a request to forget about a file handle
* @fid: handle of the file we closing or forgetting about
*
* clunk is used both to close open files and to discard transient handles
* which may be created during meta-data operations and hierarchy traversal.
*/
struct p9_fcall *p9_create_tclunk(u32 fid)
{
int size;
struct p9_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 4; /* fid[4] */
fc = p9_create_common(bufp, size, P9_TCLUNK);
if (IS_ERR(fc))
goto error;
p9_put_int32(bufp, fid, &fc->params.tclunk.fid);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
EXPORT_SYMBOL(p9_create_tclunk);
/**
* p9_create_tremove - allocate and create a request to remove a file
* @fid: handle of the file or directory we are removing
*
*/
struct p9_fcall *p9_create_tremove(u32 fid)
{
int size;
struct p9_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 4; /* fid[4] */
fc = p9_create_common(bufp, size, P9_TREMOVE);
if (IS_ERR(fc))
goto error;
p9_put_int32(bufp, fid, &fc->params.tremove.fid);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
EXPORT_SYMBOL(p9_create_tremove);
/**
* p9_create_tstat - allocate and populate a request for attributes
* @fid: handle of the file or directory we are trying to get the attributes of
*
*/
struct p9_fcall *p9_create_tstat(u32 fid)
{
int size;
struct p9_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
size = 4; /* fid[4] */
fc = p9_create_common(bufp, size, P9_TSTAT);
if (IS_ERR(fc))
goto error;
p9_put_int32(bufp, fid, &fc->params.tstat.fid);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
EXPORT_SYMBOL(p9_create_tstat);
/**
* p9_create_tstat - allocate and populate a request to change attributes
* @fid: handle of the file or directory we are trying to change
* @wstat: &p9_stat structure with attributes we wish to set
* @dotu: 9p2000.u enabled flag
*
*/
struct p9_fcall *p9_create_twstat(u32 fid, struct p9_wstat *wstat,
int dotu)
{
int size, statsz;
struct p9_fcall *fc;
struct cbuf buffer;
struct cbuf *bufp = &buffer;
statsz = p9_size_wstat(wstat, dotu);
size = 4 + 2 + 2 + statsz; /* fid[4] stat[n] */
fc = p9_create_common(bufp, size, P9_TWSTAT);
if (IS_ERR(fc))
goto error;
p9_put_int32(bufp, fid, &fc->params.twstat.fid);
buf_put_int16(bufp, statsz + 2);
p9_put_wstat(bufp, wstat, &fc->params.twstat.stat, statsz, dotu);
if (buf_check_overflow(bufp)) {
kfree(fc);
fc = ERR_PTR(-ENOMEM);
}
error:
return fc;
}
EXPORT_SYMBOL(p9_create_twstat);