Commit 3cf6429a authored by Latchesar Ionkov's avatar Latchesar Ionkov Committed by Linus Torvalds
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[PATCH] v9fs: new multiplexer implementation



New multiplexer implementation. Decreases the number of kernel threads
required. Better handling when the user process receives a signal.
Signed-off-by: default avatarLatchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent f5ef3c10
......@@ -52,10 +52,11 @@ v9fs_t_version(struct v9fs_session_info *v9ses, u32 msize,
dprintk(DEBUG_9P, "msize: %d version: %s\n", msize, version);
msg.id = TVERSION;
msg.tag = ~0;
msg.params.tversion.msize = msize;
msg.params.tversion.version = version;
return v9fs_mux_rpc(v9ses, &msg, fcall);
return v9fs_mux_rpc(v9ses->mux, &msg, fcall);
}
/**
......@@ -83,7 +84,30 @@ v9fs_t_attach(struct v9fs_session_info *v9ses, char *uname, char *aname,
msg.params.tattach.uname = uname;
msg.params.tattach.aname = aname;
return v9fs_mux_rpc(v9ses, &msg, fcall);
return v9fs_mux_rpc(v9ses->mux, &msg, fcall);
}
static void v9fs_t_clunk_cb(void *a, struct v9fs_fcall *tc,
struct v9fs_fcall *rc, int err)
{
int fid;
struct v9fs_session_info *v9ses;
if (err)
return;
fid = tc->params.tclunk.fid;
kfree(tc);
if (!rc)
return;
dprintk(DEBUG_9P, "tcall id %d rcall id %d\n", tc->id, rc->id);
v9ses = a;
if (rc->id == RCLUNK)
v9fs_put_idpool(fid, &v9ses->fidpool);
kfree(rc);
}
/**
......@@ -93,18 +117,24 @@ v9fs_t_attach(struct v9fs_session_info *v9ses, char *uname, char *aname,
* @fcall: pointer to response fcall pointer
*
*/
int
v9fs_t_clunk(struct v9fs_session_info *v9ses, u32 fid,
struct v9fs_fcall **fcall)
v9fs_t_clunk(struct v9fs_session_info *v9ses, u32 fid)
{
struct v9fs_fcall msg;
int err;
struct v9fs_fcall *tc, *rc;
tc = kmalloc(sizeof(struct v9fs_fcall), GFP_KERNEL);
dprintk(DEBUG_9P, "fid %d\n", fid);
msg.id = TCLUNK;
msg.params.tclunk.fid = fid;
tc->id = TCLUNK;
tc->params.tclunk.fid = fid;
return v9fs_mux_rpc(v9ses, &msg, fcall);
err = v9fs_mux_rpc(v9ses->mux, tc, &rc);
if (err >= 0) {
v9fs_t_clunk_cb(v9ses, tc, rc, 0);
}
return err;
}
/**
......@@ -121,7 +151,7 @@ int v9fs_t_flush(struct v9fs_session_info *v9ses, u16 tag)
dprintk(DEBUG_9P, "oldtag %d\n", tag);
msg.id = TFLUSH;
msg.params.tflush.oldtag = tag;
return v9fs_mux_rpc(v9ses, &msg, NULL);
return v9fs_mux_rpc(v9ses->mux, &msg, NULL);
}
/**
......@@ -143,7 +173,7 @@ v9fs_t_stat(struct v9fs_session_info *v9ses, u32 fid, struct v9fs_fcall **fcall)
msg.id = TSTAT;
msg.params.tstat.fid = fid;
return v9fs_mux_rpc(v9ses, &msg, fcall);
return v9fs_mux_rpc(v9ses->mux, &msg, fcall);
}
/**
......@@ -166,7 +196,7 @@ v9fs_t_wstat(struct v9fs_session_info *v9ses, u32 fid,
msg.params.twstat.fid = fid;
msg.params.twstat.stat = stat;
return v9fs_mux_rpc(v9ses, &msg, fcall);
return v9fs_mux_rpc(v9ses->mux, &msg, fcall);
}
/**
......@@ -199,7 +229,7 @@ v9fs_t_walk(struct v9fs_session_info *v9ses, u32 fid, u32 newfid,
msg.params.twalk.nwname = 0;
}
return v9fs_mux_rpc(v9ses, &msg, fcall);
return v9fs_mux_rpc(v9ses->mux, &msg, fcall);
}
/**
......@@ -217,14 +247,14 @@ v9fs_t_open(struct v9fs_session_info *v9ses, u32 fid, u8 mode,
struct v9fs_fcall **fcall)
{
struct v9fs_fcall msg;
long errorno = -1;
int errorno = -1;
dprintk(DEBUG_9P, "fid %d mode %d\n", fid, mode);
msg.id = TOPEN;
msg.params.topen.fid = fid;
msg.params.topen.mode = mode;
errorno = v9fs_mux_rpc(v9ses, &msg, fcall);
errorno = v9fs_mux_rpc(v9ses->mux, &msg, fcall);
return errorno;
}
......@@ -246,7 +276,7 @@ v9fs_t_remove(struct v9fs_session_info *v9ses, u32 fid,
dprintk(DEBUG_9P, "fid %d\n", fid);
msg.id = TREMOVE;
msg.params.tremove.fid = fid;
return v9fs_mux_rpc(v9ses, &msg, fcall);
return v9fs_mux_rpc(v9ses->mux, &msg, fcall);
}
/**
......@@ -275,7 +305,7 @@ v9fs_t_create(struct v9fs_session_info *v9ses, u32 fid, char *name,
msg.params.tcreate.perm = perm;
msg.params.tcreate.mode = mode;
return v9fs_mux_rpc(v9ses, &msg, fcall);
return v9fs_mux_rpc(v9ses->mux, &msg, fcall);
}
/**
......@@ -302,7 +332,7 @@ v9fs_t_read(struct v9fs_session_info *v9ses, u32 fid, u64 offset,
msg.params.tread.fid = fid;
msg.params.tread.offset = offset;
msg.params.tread.count = count;
errorno = v9fs_mux_rpc(v9ses, &msg, &rc);
errorno = v9fs_mux_rpc(v9ses->mux, &msg, &rc);
if (!errorno) {
errorno = rc->params.rread.count;
......@@ -345,7 +375,7 @@ v9fs_t_write(struct v9fs_session_info *v9ses, u32 fid,
msg.params.twrite.count = count;
msg.params.twrite.data = data;
errorno = v9fs_mux_rpc(v9ses, &msg, &rc);
errorno = v9fs_mux_rpc(v9ses->mux, &msg, &rc);
if (!errorno)
errorno = rc->params.rwrite.count;
......
......@@ -100,6 +100,9 @@ enum {
V9FS_QTFILE = 0x00,
};
#define V9FS_NOTAG (u16)(~0)
#define V9FS_NOFID (u32)(~0)
/* ample room for Twrite/Rread header (iounit) */
#define V9FS_IOHDRSZ 24
......@@ -303,6 +306,9 @@ struct v9fs_fcall {
} params;
};
#define V9FS_FCALLHDRSZ (sizeof(struct v9fs_fcall) + \
sizeof(struct v9fs_stat) + 16*sizeof(struct v9fs_qid) + 16)
#define FCALL_ERROR(fcall) (fcall ? fcall->params.rerror.error : "")
int v9fs_t_version(struct v9fs_session_info *v9ses, u32 msize,
......@@ -311,8 +317,7 @@ int v9fs_t_version(struct v9fs_session_info *v9ses, u32 msize,
int v9fs_t_attach(struct v9fs_session_info *v9ses, char *uname, char *aname,
u32 fid, u32 afid, struct v9fs_fcall **rcall);
int v9fs_t_clunk(struct v9fs_session_info *v9ses, u32 fid,
struct v9fs_fcall **rcall);
int v9fs_t_clunk(struct v9fs_session_info *v9ses, u32 fid);
int v9fs_t_flush(struct v9fs_session_info *v9ses, u16 oldtag);
......
......@@ -208,7 +208,7 @@ static inline char *buf_get_stringb(struct cbuf *buf, struct cbuf *sbuf)
len = buf_get_int16(buf);
if (!buf_check_overflow(buf) && buf_check_size(buf, len) &&
buf_check_size(sbuf, len+1)) {
buf_check_size(sbuf, len + 1)) {
memcpy(sbuf->p, buf->p, len);
sbuf->p[len] = 0;
......@@ -252,13 +252,12 @@ static inline void *buf_get_datab(struct cbuf *buf, struct cbuf *dbuf,
/**
* v9fs_size_stat - calculate the size of a variable length stat struct
* @v9ses: session information
* @stat: metadata (stat) structure
* @extended: non-zero if 9P2000.u
*
*/
static int v9fs_size_stat(struct v9fs_session_info *v9ses,
struct v9fs_stat *stat)
static int v9fs_size_stat(struct v9fs_stat *stat, int extended)
{
int size = 0;
......@@ -288,7 +287,7 @@ static int v9fs_size_stat(struct v9fs_session_info *v9ses,
if (stat->muid)
size += strlen(stat->muid);
if (v9ses->extended) {
if (extended) {
size += 4 + /* n_uid[4] */
4 + /* n_gid[4] */
4 + /* n_muid[4] */
......@@ -302,15 +301,14 @@ static int v9fs_size_stat(struct v9fs_session_info *v9ses,
/**
* serialize_stat - safely format a stat structure for transmission
* @v9ses: session info
* @stat: metadata (stat) structure
* @bufp: buffer to serialize structure into
* @extended: non-zero if 9P2000.u
*
*/
static int
serialize_stat(struct v9fs_session_info *v9ses, struct v9fs_stat *stat,
struct cbuf *bufp)
serialize_stat(struct v9fs_stat *stat, struct cbuf *bufp, int extended)
{
buf_put_int16(bufp, stat->size);
buf_put_int16(bufp, stat->type);
......@@ -328,7 +326,7 @@ serialize_stat(struct v9fs_session_info *v9ses, struct v9fs_stat *stat,
buf_put_string(bufp, stat->gid);
buf_put_string(bufp, stat->muid);
if (v9ses->extended) {
if (extended) {
buf_put_string(bufp, stat->extension);
buf_put_int32(bufp, stat->n_uid);
buf_put_int32(bufp, stat->n_gid);
......@@ -343,16 +341,16 @@ serialize_stat(struct v9fs_session_info *v9ses, struct v9fs_stat *stat,
/**
* deserialize_stat - safely decode a recieved metadata (stat) structure
* @v9ses: session info
* @bufp: buffer to deserialize
* @stat: metadata (stat) structure
* @dbufp: buffer to deserialize variable strings into
* @extended: non-zero if 9P2000.u
*
*/
static inline int
deserialize_stat(struct v9fs_session_info *v9ses, struct cbuf *bufp,
struct v9fs_stat *stat, struct cbuf *dbufp)
deserialize_stat(struct cbuf *bufp, struct v9fs_stat *stat,
struct cbuf *dbufp, int extended)
{
stat->size = buf_get_int16(bufp);
......@@ -370,7 +368,7 @@ deserialize_stat(struct v9fs_session_info *v9ses, struct cbuf *bufp,
stat->gid = buf_get_stringb(bufp, dbufp);
stat->muid = buf_get_stringb(bufp, dbufp);
if (v9ses->extended) {
if (extended) {
stat->extension = buf_get_stringb(bufp, dbufp);
stat->n_uid = buf_get_int32(bufp);
stat->n_gid = buf_get_int32(bufp);
......@@ -385,20 +383,20 @@ deserialize_stat(struct v9fs_session_info *v9ses, struct cbuf *bufp,
/**
* deserialize_statb - wrapper for decoding a received metadata structure
* @v9ses: session info
* @bufp: buffer to deserialize
* @dbufp: buffer to deserialize variable strings into
* @extended: non-zero if 9P2000.u
*
*/
static inline struct v9fs_stat *deserialize_statb(struct v9fs_session_info
*v9ses, struct cbuf *bufp,
struct cbuf *dbufp)
static inline struct v9fs_stat *deserialize_statb(struct cbuf *bufp,
struct cbuf *dbufp,
int extended)
{
struct v9fs_stat *ret = buf_alloc(dbufp, sizeof(struct v9fs_stat));
if (ret) {
int n = deserialize_stat(v9ses, bufp, ret, dbufp);
int n = deserialize_stat(bufp, ret, dbufp, extended);
if (n <= 0)
return NULL;
}
......@@ -408,17 +406,16 @@ static inline struct v9fs_stat *deserialize_statb(struct v9fs_session_info
/**
* v9fs_deserialize_stat - decode a received metadata structure
* @v9ses: session info
* @buf: buffer to deserialize
* @buflen: length of received buffer
* @stat: metadata structure to decode into
* @statlen: length of destination metadata structure
* @extended: non-zero if 9P2000.u
*
*/
int
v9fs_deserialize_stat(struct v9fs_session_info *v9ses, void *buf,
u32 buflen, struct v9fs_stat *stat, u32 statlen)
int v9fs_deserialize_stat(void *buf, u32 buflen, struct v9fs_stat *stat,
u32 statlen, int extended)
{
struct cbuf buffer;
struct cbuf *bufp = &buffer;
......@@ -429,11 +426,10 @@ v9fs_deserialize_stat(struct v9fs_session_info *v9ses, void *buf,
buf_init(dbufp, (char *)stat + sizeof(struct v9fs_stat),
statlen - sizeof(struct v9fs_stat));
return deserialize_stat(v9ses, bufp, stat, dbufp);
return deserialize_stat(bufp, stat, dbufp, extended);
}
static inline int
v9fs_size_fcall(struct v9fs_session_info *v9ses, struct v9fs_fcall *fcall)
static inline int v9fs_size_fcall(struct v9fs_fcall *fcall, int extended)
{
int size = 4 + 1 + 2; /* size[4] msg[1] tag[2] */
int i = 0;
......@@ -485,7 +481,7 @@ v9fs_size_fcall(struct v9fs_session_info *v9ses, struct v9fs_fcall *fcall)
break;
case TWSTAT: /* fid[4] stat[n] */
fcall->params.twstat.stat->size =
v9fs_size_stat(v9ses, fcall->params.twstat.stat);
v9fs_size_stat(fcall->params.twstat.stat, extended);
size += 4 + 2 + 2 + fcall->params.twstat.stat->size;
}
return size;
......@@ -493,16 +489,16 @@ v9fs_size_fcall(struct v9fs_session_info *v9ses, struct v9fs_fcall *fcall)
/*
* v9fs_serialize_fcall - marshall fcall struct into a packet
* @v9ses: session information
* @fcall: structure to convert
* @data: buffer to serialize fcall into
* @datalen: length of buffer to serialize fcall into
* @extended: non-zero if 9P2000.u
*
*/
int
v9fs_serialize_fcall(struct v9fs_session_info *v9ses, struct v9fs_fcall *fcall,
void *data, u32 datalen)
v9fs_serialize_fcall(struct v9fs_fcall *fcall, void *data, u32 datalen,
int extended)
{
int i = 0;
struct v9fs_stat *stat = NULL;
......@@ -516,7 +512,7 @@ v9fs_serialize_fcall(struct v9fs_session_info *v9ses, struct v9fs_fcall *fcall,
return -EINVAL;
}
fcall->size = v9fs_size_fcall(v9ses, fcall);
fcall->size = v9fs_size_fcall(fcall, extended);
buf_put_int32(bufp, fcall->size);
buf_put_int8(bufp, fcall->id);
......@@ -591,31 +587,31 @@ v9fs_serialize_fcall(struct v9fs_session_info *v9ses, struct v9fs_fcall *fcall,
stat = fcall->params.twstat.stat;
buf_put_int16(bufp, stat->size + 2);
serialize_stat(v9ses, stat, bufp);
serialize_stat(stat, bufp, extended);
break;
}
if (buf_check_overflow(bufp))
if (buf_check_overflow(bufp)) {
dprintk(DEBUG_ERROR, "buffer overflow\n");
return -EIO;
}
return fcall->size;
}
/**
* deserialize_fcall - unmarshal a response
* @v9ses: session information
* @msgsize: size of rcall message
* @buf: recieved buffer
* @buflen: length of received buffer
* @rcall: fcall structure to populate
* @rcalllen: length of fcall structure to populate
* @extended: non-zero if 9P2000.u
*
*/
int
v9fs_deserialize_fcall(struct v9fs_session_info *v9ses, u32 msgsize,
void *buf, u32 buflen, struct v9fs_fcall *rcall,
int rcalllen)
v9fs_deserialize_fcall(void *buf, u32 buflen, struct v9fs_fcall *rcall,
int rcalllen, int extended)
{
struct cbuf buffer;
......@@ -628,7 +624,7 @@ v9fs_deserialize_fcall(struct v9fs_session_info *v9ses, u32 msgsize,
buf_init(dbufp, (char *)rcall + sizeof(struct v9fs_fcall),
rcalllen - sizeof(struct v9fs_fcall));
rcall->size = msgsize;
rcall->size = buf_get_int32(bufp);
rcall->id = buf_get_int8(bufp);
rcall->tag = buf_get_int16(bufp);
......@@ -651,6 +647,12 @@ v9fs_deserialize_fcall(struct v9fs_session_info *v9ses, u32 msgsize,
break;
case RWALK:
rcall->params.rwalk.nwqid = buf_get_int16(bufp);
if (rcall->params.rwalk.nwqid > 16) {
eprintk(KERN_ERR, "Rwalk with more than 16 qids: %d\n",
rcall->params.rwalk.nwqid);
return -EPROTO;
}
rcall->params.rwalk.wqids = buf_alloc(dbufp,
rcall->params.rwalk.nwqid * sizeof(struct v9fs_qid));
if (rcall->params.rwalk.wqids)
......@@ -690,19 +692,21 @@ v9fs_deserialize_fcall(struct v9fs_session_info *v9ses, u32 msgsize,
case RSTAT:
buf_get_int16(bufp);
rcall->params.rstat.stat =
deserialize_statb(v9ses, bufp, dbufp);
deserialize_statb(bufp, dbufp, extended);
break;
case RWSTAT:
break;
case RERROR:
rcall->params.rerror.error = buf_get_stringb(bufp, dbufp);
if (v9ses->extended)
if (extended)
rcall->params.rerror.errno = buf_get_int16(bufp);
break;
}
if (buf_check_overflow(bufp) || buf_check_overflow(dbufp))
if (buf_check_overflow(bufp) || buf_check_overflow(dbufp)) {
dprintk(DEBUG_ERROR, "buffer overflow\n");
return -EIO;
}
return rcall->size;
}
......@@ -24,13 +24,12 @@
*
*/
int v9fs_deserialize_stat(struct v9fs_session_info *, void *buf,
u32 buflen, struct v9fs_stat *stat, u32 statlen);
int v9fs_serialize_fcall(struct v9fs_session_info *, struct v9fs_fcall *tcall,
void *buf, u32 buflen);
int v9fs_deserialize_fcall(struct v9fs_session_info *, u32 msglen,
void *buf, u32 buflen, struct v9fs_fcall *rcall,
int rcalllen);
int v9fs_deserialize_stat(void *buf, u32 buflen, struct v9fs_stat *stat,
u32 statlen, int extended);
int v9fs_serialize_fcall(struct v9fs_fcall *tcall, void *buf, u32 buflen,
int extended);
int v9fs_deserialize_fcall(void *buf, u32 buflen, struct v9fs_fcall *rcall,
int rcalllen, int extended);
/* this one is actually in error.c right now */
int v9fs_errstr2errno(char *errstr);
......@@ -164,7 +164,7 @@ static struct v9fs_fid *v9fs_fid_walk_up(struct dentry *dentry)
return v9fs_fid_create(dentry, v9ses, fidnum, 0);
clunk_fid:
v9fs_t_clunk(v9ses, fidnum, NULL);
v9fs_t_clunk(v9ses, fidnum);
return ERR_PTR(err);
}
......
This diff is collapsed.
......@@ -3,6 +3,7 @@
*
* Multiplexer Definitions
*
* Copyright (C) 2005 by Latchesar Ionkov <lucho@ionkov.net>
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
......@@ -23,19 +24,34 @@
*
*/
/* structure to manage each RPC transaction */
struct v9fs_mux_data;
struct v9fs_rpcreq {
struct v9fs_fcall *tcall;
struct v9fs_fcall *rcall;
int err; /* error code if response failed */
/**
* v9fs_mux_req_callback - callback function that is called when the
* response of a request is received. The callback is called from
* a workqueue and shouldn't block.
*
* @a - the pointer that was specified when the request was send to be
* passed to the callback
* @tc - request call
* @rc - response call
* @err - error code (non-zero if error occured)
*/
typedef void (*v9fs_mux_req_callback)(void *a, struct v9fs_fcall *tc,
struct v9fs_fcall *rc, int err);
void v9fs_mux_global_init(void);
void v9fs_mux_global_exit(void);
/* XXX - could we put scatter/gather buffers here? */
struct v9fs_mux_data *v9fs_mux_init(struct v9fs_transport *trans, int msize,
unsigned char *extended);
void v9fs_mux_destroy(struct v9fs_mux_data *);
struct list_head next;
};
int v9fs_mux_send(struct v9fs_mux_data *m, struct v9fs_fcall *tc);
struct v9fs_fcall *v9fs_mux_recv(struct v9fs_mux_data *m);
int v9fs_mux_rpc(struct v9fs_mux_data *m, struct v9fs_fcall *tc, struct v9fs_fcall **rc);
int v9fs_mux_rpcnb(struct v9fs_mux_data *m, struct v9fs_fcall *tc,
v9fs_mux_req_callback cb, void *a);
int v9fs_mux_init(struct v9fs_session_info *v9ses, const char *dev_name);
long v9fs_mux_rpc(struct v9fs_session_info *v9ses,
struct v9fs_fcall *tcall, struct v9fs_fcall **rcall);
void v9fs_mux_cancel_requests(struct v9fs_session_info *v9ses, int err);
void v9fs_mux_flush(struct v9fs_mux_data *m, int sendflush);
void v9fs_mux_cancel(struct v9fs_mux_data *m, int err);
......@@ -3,6 +3,7 @@
*
* File Descriptor Transport Layer
*
* Copyright (C) 2005 by Latchesar Ionkov <lucho@ionkov.net>
* Copyright (C) 2005 by Eric Van Hensbergen <ericvh@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
......@@ -106,9 +107,6 @@ v9fs_fd_init(struct v9fs_session_info *v9ses, const char *addr, char *data)
return -ENOPROTOOPT;
}
sema_init(&trans->writelock, 1);
sema_init(&trans->readlock, 1);
ts = kmalloc(sizeof(struct v9fs_trans_fd), GFP_KERNEL);
if (!ts)
......@@ -163,10 +161,55 @@ static void v9fs_fd_close(struct v9fs_transport *trans)
kfree(ts);
}
static unsigned int
v9fs_fd_poll(struct v9fs_transport *trans, struct poll_table_struct *pt)
{
int ret, n;
struct v9fs_trans_fd *ts;
mm_segment_t oldfs;
if (!trans)
return -EIO;
ts = trans->priv;
if (trans->status != Connected || !ts)
return -EIO;
oldfs = get_fs();
set_fs(get_ds());
if (!ts->in_file->f_op || !ts->in_file->f_op->poll) {
ret = -EIO;
goto end;
}
ret = ts->in_file->f_op->poll(ts->in_file, pt);
if (ts->out_file != ts->in_file) {
if (!ts->out_file->f_op || !ts->out_file->f_op->poll) {
ret = -EIO;
goto end;
}
n = ts->out_file->f_op->poll(ts->out_file, pt);
ret &= ~POLLOUT;
n &= ~POLLIN;
ret |= n;
}
end:
set_fs(oldfs);
return ret;
}
struct v9fs_transport v9fs_trans_fd = {
.init = v9fs_fd_init,
.write = v9fs_fd_send,
.read = v9fs_fd_recv,
.close = v9fs_fd_close,
.poll = v9fs_fd_poll,
};
......@@ -3,6 +3,7 @@
*
* Socket Transport Layer
*
* Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
* Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
* Copyright (C) 1995, 1996 by Olaf Kirch <okir@monad.swb.de>
......@@ -36,6 +37,7 @@
#include <asm/uaccess.h>
#include <linux/inet.h>
#include <linux/idr.h>
#include <linux/file.h>