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Re: [PATCH 04/30] virtiofsd: Add fuse_lowlevel.c


From: Dr. David Alan Gilbert
Subject: Re: [PATCH 04/30] virtiofsd: Add fuse_lowlevel.c
Date: Thu, 24 Oct 2019 15:31:16 +0100
User-agent: Mutt/1.12.1 (2019-06-15)

* Michael S. Tsirkin (address@hidden) wrote:
> On Mon, Oct 21, 2019 at 11:58:06AM +0100, Dr. David Alan Gilbert (git) wrote:
> > From: "Dr. David Alan Gilbert" <address@hidden>
> > 
> > fuse_lowlevel is one of the largest files from the library
> > and does most of the work.  Add it separately to keep the diff
> > sizes small.
> > Again this is from upstream a0d713619d4f21e8240ede38eefe6101ea580724
> > 
> > Signed-off-by: Dr. David Alan Gilbert <address@hidden>
> > ---
> >  contrib/virtiofsd/fuse_lowlevel.c | 3104 +++++++++++++++++++++++++++++
> >  1 file changed, 3104 insertions(+)
> >  create mode 100644 contrib/virtiofsd/fuse_lowlevel.c
> > 
> > diff --git a/contrib/virtiofsd/fuse_lowlevel.c 
> > b/contrib/virtiofsd/fuse_lowlevel.c
> > new file mode 100644
> > index 0000000000..f7fbc8f5db
> > --- /dev/null
> > +++ b/contrib/virtiofsd/fuse_lowlevel.c
> > @@ -0,0 +1,3104 @@
> > +/*
> > +  FUSE: Filesystem in Userspace
> > +  Copyright (C) 2001-2007  Miklos Szeredi <address@hidden>
> > +
> > +  Implementation of (most of) the low-level FUSE API. The session loop
> > +  functions are implemented in separate files.
> > +
> > +  This program can be distributed under the terms of the GNU LGPLv2.
> > +  See the file COPYING.LIB
> 
> I guess we need COPYING.LIB then?

We already do; it has GPL 2.1 in (again libfuse's is called LGPL2.txt
but ours matches).

Dave

> > +*/
> > +
> > +#define _GNU_SOURCE
> > +
> > +#include "config.h"
> > +#include "fuse_i.h"
> > +#include "fuse_kernel.h"
> > +#include "fuse_opt.h"
> > +#include "fuse_misc.h"
> > +#include "mount_util.h"
> > +
> > +#include <stdio.h>
> > +#include <stdlib.h>
> > +#include <stddef.h>
> > +#include <string.h>
> > +#include <unistd.h>
> > +#include <limits.h>
> > +#include <errno.h>
> > +#include <assert.h>
> > +#include <sys/file.h>
> > +
> > +#ifndef F_LINUX_SPECIFIC_BASE
> > +#define F_LINUX_SPECIFIC_BASE       1024
> > +#endif
> > +#ifndef F_SETPIPE_SZ
> > +#define F_SETPIPE_SZ       (F_LINUX_SPECIFIC_BASE + 7)
> > +#endif
> > +
> > +
> > +#define PARAM(inarg) (((char *)(inarg)) + sizeof(*(inarg)))
> > +#define OFFSET_MAX 0x7fffffffffffffffLL
> > +
> > +#define container_of(ptr, type, member) ({                         \
> > +                   const typeof( ((type *)0)->member ) *__mptr = (ptr); \
> > +                   (type *)( (char *)__mptr - offsetof(type,member) );})
> > +
> > +struct fuse_pollhandle {
> > +   uint64_t kh;
> > +   struct fuse_session *se;
> > +};
> > +
> > +static size_t pagesize;
> > +
> > +static __attribute__((constructor)) void fuse_ll_init_pagesize(void)
> > +{
> > +   pagesize = getpagesize();
> > +}
> > +
> > +static void convert_stat(const struct stat *stbuf, struct fuse_attr *attr)
> > +{
> > +   attr->ino       = stbuf->st_ino;
> > +   attr->mode      = stbuf->st_mode;
> > +   attr->nlink     = stbuf->st_nlink;
> > +   attr->uid       = stbuf->st_uid;
> > +   attr->gid       = stbuf->st_gid;
> > +   attr->rdev      = stbuf->st_rdev;
> > +   attr->size      = stbuf->st_size;
> > +   attr->blksize   = stbuf->st_blksize;
> > +   attr->blocks    = stbuf->st_blocks;
> > +   attr->atime     = stbuf->st_atime;
> > +   attr->mtime     = stbuf->st_mtime;
> > +   attr->ctime     = stbuf->st_ctime;
> > +   attr->atimensec = ST_ATIM_NSEC(stbuf);
> > +   attr->mtimensec = ST_MTIM_NSEC(stbuf);
> > +   attr->ctimensec = ST_CTIM_NSEC(stbuf);
> > +}
> > +
> > +static void convert_attr(const struct fuse_setattr_in *attr, struct stat 
> > *stbuf)
> > +{
> > +   stbuf->st_mode         = attr->mode;
> > +   stbuf->st_uid          = attr->uid;
> > +   stbuf->st_gid          = attr->gid;
> > +   stbuf->st_size         = attr->size;
> > +   stbuf->st_atime        = attr->atime;
> > +   stbuf->st_mtime        = attr->mtime;
> > +   stbuf->st_ctime        = attr->ctime;
> > +   ST_ATIM_NSEC_SET(stbuf, attr->atimensec);
> > +   ST_MTIM_NSEC_SET(stbuf, attr->mtimensec);
> > +   ST_CTIM_NSEC_SET(stbuf, attr->ctimensec);
> > +}
> > +
> > +static     size_t iov_length(const struct iovec *iov, size_t count)
> > +{
> > +   size_t seg;
> > +   size_t ret = 0;
> > +
> > +   for (seg = 0; seg < count; seg++)
> > +           ret += iov[seg].iov_len;
> > +   return ret;
> > +}
> > +
> > +static void list_init_req(struct fuse_req *req)
> > +{
> > +   req->next = req;
> > +   req->prev = req;
> > +}
> > +
> > +static void list_del_req(struct fuse_req *req)
> > +{
> > +   struct fuse_req *prev = req->prev;
> > +   struct fuse_req *next = req->next;
> > +   prev->next = next;
> > +   next->prev = prev;
> > +}
> > +
> > +static void list_add_req(struct fuse_req *req, struct fuse_req *next)
> > +{
> > +   struct fuse_req *prev = next->prev;
> > +   req->next = next;
> > +   req->prev = prev;
> > +   prev->next = req;
> > +   next->prev = req;
> > +}
> > +
> > +static void destroy_req(fuse_req_t req)
> > +{
> > +   pthread_mutex_destroy(&req->lock);
> > +   free(req);
> > +}
> > +
> > +void fuse_free_req(fuse_req_t req)
> > +{
> > +   int ctr;
> > +   struct fuse_session *se = req->se;
> > +
> > +   pthread_mutex_lock(&se->lock);
> > +   req->u.ni.func = NULL;
> > +   req->u.ni.data = NULL;
> > +   list_del_req(req);
> > +   ctr = --req->ctr;
> > +   fuse_chan_put(req->ch);
> > +   req->ch = NULL;
> > +   pthread_mutex_unlock(&se->lock);
> > +   if (!ctr)
> > +           destroy_req(req);
> > +}
> > +
> > +static struct fuse_req *fuse_ll_alloc_req(struct fuse_session *se)
> > +{
> > +   struct fuse_req *req;
> > +
> > +   req = (struct fuse_req *) calloc(1, sizeof(struct fuse_req));
> > +   if (req == NULL) {
> > +           fuse_log(FUSE_LOG_ERR, "fuse: failed to allocate request\n");
> > +   } else {
> > +           req->se = se;
> > +           req->ctr = 1;
> > +           list_init_req(req);
> > +           fuse_mutex_init(&req->lock);
> > +   }
> > +
> > +   return req;
> > +}
> > +
> > +/* Send data. If *ch* is NULL, send via session master fd */
> > +static int fuse_send_msg(struct fuse_session *se, struct fuse_chan *ch,
> > +                    struct iovec *iov, int count)
> > +{
> > +   struct fuse_out_header *out = iov[0].iov_base;
> > +
> > +   out->len = iov_length(iov, count);
> > +   if (se->debug) {
> > +           if (out->unique == 0) {
> > +                   fuse_log(FUSE_LOG_DEBUG, "NOTIFY: code=%d length=%u\n",
> > +                           out->error, out->len);
> > +           } else if (out->error) {
> > +                   fuse_log(FUSE_LOG_DEBUG,
> > +                           "   unique: %llu, error: %i (%s), outsize: 
> > %i\n",
> > +                           (unsigned long long) out->unique, out->error,
> > +                           strerror(-out->error), out->len);
> > +           } else {
> > +                   fuse_log(FUSE_LOG_DEBUG,
> > +                           "   unique: %llu, success, outsize: %i\n",
> > +                           (unsigned long long) out->unique, out->len);
> > +           }
> > +   }
> > +
> > +   ssize_t res = writev(ch ? ch->fd : se->fd,
> > +                        iov, count);
> > +   int err = errno;
> > +
> > +   if (res == -1) {
> > +           assert(se != NULL);
> > +
> > +           /* ENOENT means the operation was interrupted */
> > +           if (!fuse_session_exited(se) && err != ENOENT)
> > +                   perror("fuse: writing device");
> > +           return -err;
> > +   }
> > +
> > +   return 0;
> > +}
> > +
> > +
> > +int fuse_send_reply_iov_nofree(fuse_req_t req, int error, struct iovec 
> > *iov,
> > +                          int count)
> > +{
> > +   struct fuse_out_header out;
> > +
> > +   if (error <= -1000 || error > 0) {
> > +           fuse_log(FUSE_LOG_ERR, "fuse: bad error value: %i\n",   error);
> > +           error = -ERANGE;
> > +   }
> > +
> > +   out.unique = req->unique;
> > +   out.error = error;
> > +
> > +   iov[0].iov_base = &out;
> > +   iov[0].iov_len = sizeof(struct fuse_out_header);
> > +
> > +   return fuse_send_msg(req->se, req->ch, iov, count);
> > +}
> > +
> > +static int send_reply_iov(fuse_req_t req, int error, struct iovec *iov,
> > +                     int count)
> > +{
> > +   int res;
> > +
> > +   res = fuse_send_reply_iov_nofree(req, error, iov, count);
> > +   fuse_free_req(req);
> > +   return res;
> > +}
> > +
> > +static int send_reply(fuse_req_t req, int error, const void *arg,
> > +                 size_t argsize)
> > +{
> > +   struct iovec iov[2];
> > +   int count = 1;
> > +   if (argsize) {
> > +           iov[1].iov_base = (void *) arg;
> > +           iov[1].iov_len = argsize;
> > +           count++;
> > +   }
> > +   return send_reply_iov(req, error, iov, count);
> > +}
> > +
> > +int fuse_reply_iov(fuse_req_t req, const struct iovec *iov, int count)
> > +{
> > +   int res;
> > +   struct iovec *padded_iov;
> > +
> > +   padded_iov = malloc((count + 1) * sizeof(struct iovec));
> > +   if (padded_iov == NULL)
> > +           return fuse_reply_err(req, ENOMEM);
> > +
> > +   memcpy(padded_iov + 1, iov, count * sizeof(struct iovec));
> > +   count++;
> > +
> > +   res = send_reply_iov(req, 0, padded_iov, count);
> > +   free(padded_iov);
> > +
> > +   return res;
> > +}
> > +
> > +
> > +/* `buf` is allowed to be empty so that the proper size may be
> > +   allocated by the caller */
> > +size_t fuse_add_direntry(fuse_req_t req, char *buf, size_t bufsize,
> > +                    const char *name, const struct stat *stbuf, off_t off)
> > +{
> > +   (void)req;
> > +   size_t namelen;
> > +   size_t entlen;
> > +   size_t entlen_padded;
> > +   struct fuse_dirent *dirent;
> > +
> > +   namelen = strlen(name);
> > +   entlen = FUSE_NAME_OFFSET + namelen;
> > +   entlen_padded = FUSE_DIRENT_ALIGN(entlen);
> > +
> > +   if ((buf == NULL) || (entlen_padded > bufsize))
> > +     return entlen_padded;
> > +
> > +   dirent = (struct fuse_dirent*) buf;
> > +   dirent->ino = stbuf->st_ino;
> > +   dirent->off = off;
> > +   dirent->namelen = namelen;
> > +   dirent->type = (stbuf->st_mode & S_IFMT) >> 12;
> > +   memcpy(dirent->name, name, namelen);
> > +   memset(dirent->name + namelen, 0, entlen_padded - entlen);
> > +
> > +   return entlen_padded;
> > +}
> > +
> > +static void convert_statfs(const struct statvfs *stbuf,
> > +                      struct fuse_kstatfs *kstatfs)
> > +{
> > +   kstatfs->bsize   = stbuf->f_bsize;
> > +   kstatfs->frsize  = stbuf->f_frsize;
> > +   kstatfs->blocks  = stbuf->f_blocks;
> > +   kstatfs->bfree   = stbuf->f_bfree;
> > +   kstatfs->bavail  = stbuf->f_bavail;
> > +   kstatfs->files   = stbuf->f_files;
> > +   kstatfs->ffree   = stbuf->f_ffree;
> > +   kstatfs->namelen = stbuf->f_namemax;
> > +}
> > +
> > +static int send_reply_ok(fuse_req_t req, const void *arg, size_t argsize)
> > +{
> > +   return send_reply(req, 0, arg, argsize);
> > +}
> > +
> > +int fuse_reply_err(fuse_req_t req, int err)
> > +{
> > +   return send_reply(req, -err, NULL, 0);
> > +}
> > +
> > +void fuse_reply_none(fuse_req_t req)
> > +{
> > +   fuse_free_req(req);
> > +}
> > +
> > +static unsigned long calc_timeout_sec(double t)
> > +{
> > +   if (t > (double) ULONG_MAX)
> > +           return ULONG_MAX;
> > +   else if (t < 0.0)
> > +           return 0;
> > +   else
> > +           return (unsigned long) t;
> > +}
> > +
> > +static unsigned int calc_timeout_nsec(double t)
> > +{
> > +   double f = t - (double) calc_timeout_sec(t);
> > +   if (f < 0.0)
> > +           return 0;
> > +   else if (f >= 0.999999999)
> > +           return 999999999;
> > +   else
> > +           return (unsigned int) (f * 1.0e9);
> > +}
> > +
> > +static void fill_entry(struct fuse_entry_out *arg,
> > +                  const struct fuse_entry_param *e)
> > +{
> > +   arg->nodeid = e->ino;
> > +   arg->generation = e->generation;
> > +   arg->entry_valid = calc_timeout_sec(e->entry_timeout);
> > +   arg->entry_valid_nsec = calc_timeout_nsec(e->entry_timeout);
> > +   arg->attr_valid = calc_timeout_sec(e->attr_timeout);
> > +   arg->attr_valid_nsec = calc_timeout_nsec(e->attr_timeout);
> > +   convert_stat(&e->attr, &arg->attr);
> > +}
> > +
> > +/* `buf` is allowed to be empty so that the proper size may be
> > +   allocated by the caller */
> > +size_t fuse_add_direntry_plus(fuse_req_t req, char *buf, size_t bufsize,
> > +                         const char *name,
> > +                         const struct fuse_entry_param *e, off_t off)
> > +{
> > +   (void)req;
> > +   size_t namelen;
> > +   size_t entlen;
> > +   size_t entlen_padded;
> > +
> > +   namelen = strlen(name);
> > +   entlen = FUSE_NAME_OFFSET_DIRENTPLUS + namelen;
> > +   entlen_padded = FUSE_DIRENT_ALIGN(entlen);
> > +   if ((buf == NULL) || (entlen_padded > bufsize))
> > +     return entlen_padded;
> > +
> > +   struct fuse_direntplus *dp = (struct fuse_direntplus *) buf;
> > +   memset(&dp->entry_out, 0, sizeof(dp->entry_out));
> > +   fill_entry(&dp->entry_out, e);
> > +
> > +   struct fuse_dirent *dirent = &dp->dirent;
> > +   dirent->ino = e->attr.st_ino;
> > +   dirent->off = off;
> > +   dirent->namelen = namelen;
> > +   dirent->type = (e->attr.st_mode & S_IFMT) >> 12;
> > +   memcpy(dirent->name, name, namelen);
> > +   memset(dirent->name + namelen, 0, entlen_padded - entlen);
> > +
> > +   return entlen_padded;
> > +}
> > +
> > +static void fill_open(struct fuse_open_out *arg,
> > +                 const struct fuse_file_info *f)
> > +{
> > +   arg->fh = f->fh;
> > +   if (f->direct_io)
> > +           arg->open_flags |= FOPEN_DIRECT_IO;
> > +   if (f->keep_cache)
> > +           arg->open_flags |= FOPEN_KEEP_CACHE;
> > +   if (f->cache_readdir)
> > +           arg->open_flags |= FOPEN_CACHE_DIR;
> > +   if (f->nonseekable)
> > +           arg->open_flags |= FOPEN_NONSEEKABLE;
> > +}
> > +
> > +int fuse_reply_entry(fuse_req_t req, const struct fuse_entry_param *e)
> > +{
> > +   struct fuse_entry_out arg;
> > +   size_t size = req->se->conn.proto_minor < 9 ?
> > +           FUSE_COMPAT_ENTRY_OUT_SIZE : sizeof(arg);
> > +
> > +   /* before ABI 7.4 e->ino == 0 was invalid, only ENOENT meant
> > +      negative entry */
> > +   if (!e->ino && req->se->conn.proto_minor < 4)
> > +           return fuse_reply_err(req, ENOENT);
> > +
> > +   memset(&arg, 0, sizeof(arg));
> > +   fill_entry(&arg, e);
> > +   return send_reply_ok(req, &arg, size);
> > +}
> > +
> > +int fuse_reply_create(fuse_req_t req, const struct fuse_entry_param *e,
> > +                 const struct fuse_file_info *f)
> > +{
> > +   char buf[sizeof(struct fuse_entry_out) + sizeof(struct fuse_open_out)];
> > +   size_t entrysize = req->se->conn.proto_minor < 9 ?
> > +           FUSE_COMPAT_ENTRY_OUT_SIZE : sizeof(struct fuse_entry_out);
> > +   struct fuse_entry_out *earg = (struct fuse_entry_out *) buf;
> > +   struct fuse_open_out *oarg = (struct fuse_open_out *) (buf + entrysize);
> > +
> > +   memset(buf, 0, sizeof(buf));
> > +   fill_entry(earg, e);
> > +   fill_open(oarg, f);
> > +   return send_reply_ok(req, buf,
> > +                        entrysize + sizeof(struct fuse_open_out));
> > +}
> > +
> > +int fuse_reply_attr(fuse_req_t req, const struct stat *attr,
> > +               double attr_timeout)
> > +{
> > +   struct fuse_attr_out arg;
> > +   size_t size = req->se->conn.proto_minor < 9 ?
> > +           FUSE_COMPAT_ATTR_OUT_SIZE : sizeof(arg);
> > +
> > +   memset(&arg, 0, sizeof(arg));
> > +   arg.attr_valid = calc_timeout_sec(attr_timeout);
> > +   arg.attr_valid_nsec = calc_timeout_nsec(attr_timeout);
> > +   convert_stat(attr, &arg.attr);
> > +
> > +   return send_reply_ok(req, &arg, size);
> > +}
> > +
> > +int fuse_reply_readlink(fuse_req_t req, const char *linkname)
> > +{
> > +   return send_reply_ok(req, linkname, strlen(linkname));
> > +}
> > +
> > +int fuse_reply_open(fuse_req_t req, const struct fuse_file_info *f)
> > +{
> > +   struct fuse_open_out arg;
> > +
> > +   memset(&arg, 0, sizeof(arg));
> > +   fill_open(&arg, f);
> > +   return send_reply_ok(req, &arg, sizeof(arg));
> > +}
> > +
> > +int fuse_reply_write(fuse_req_t req, size_t count)
> > +{
> > +   struct fuse_write_out arg;
> > +
> > +   memset(&arg, 0, sizeof(arg));
> > +   arg.size = count;
> > +
> > +   return send_reply_ok(req, &arg, sizeof(arg));
> > +}
> > +
> > +int fuse_reply_buf(fuse_req_t req, const char *buf, size_t size)
> > +{
> > +   return send_reply_ok(req, buf, size);
> > +}
> > +
> > +static int fuse_send_data_iov_fallback(struct fuse_session *se,
> > +                                  struct fuse_chan *ch,
> > +                                  struct iovec *iov, int iov_count,
> > +                                  struct fuse_bufvec *buf,
> > +                                  size_t len)
> > +{
> > +   struct fuse_bufvec mem_buf = FUSE_BUFVEC_INIT(len);
> > +   void *mbuf;
> > +   int res;
> > +
> > +   /* Optimize common case */
> > +   if (buf->count == 1 && buf->idx == 0 && buf->off == 0 &&
> > +       !(buf->buf[0].flags & FUSE_BUF_IS_FD)) {
> > +           /* FIXME: also avoid memory copy if there are multiple buffers
> > +              but none of them contain an fd */
> > +
> > +           iov[iov_count].iov_base = buf->buf[0].mem;
> > +           iov[iov_count].iov_len = len;
> > +           iov_count++;
> > +           return fuse_send_msg(se, ch, iov, iov_count);
> > +   }
> > +
> > +   res = posix_memalign(&mbuf, pagesize, len);
> > +   if (res != 0)
> > +           return res;
> > +
> > +   mem_buf.buf[0].mem = mbuf;
> > +   res = fuse_buf_copy(&mem_buf, buf, 0);
> > +   if (res < 0) {
> > +           free(mbuf);
> > +           return -res;
> > +   }
> > +   len = res;
> > +
> > +   iov[iov_count].iov_base = mbuf;
> > +   iov[iov_count].iov_len = len;
> > +   iov_count++;
> > +   res = fuse_send_msg(se, ch, iov, iov_count);
> > +   free(mbuf);
> > +
> > +   return res;
> > +}
> > +
> > +struct fuse_ll_pipe {
> > +   size_t size;
> > +   int can_grow;
> > +   int pipe[2];
> > +};
> > +
> > +static void fuse_ll_pipe_free(struct fuse_ll_pipe *llp)
> > +{
> > +   close(llp->pipe[0]);
> > +   close(llp->pipe[1]);
> > +   free(llp);
> > +}
> > +
> > +#ifdef HAVE_SPLICE
> > +#if !defined(HAVE_PIPE2) || !defined(O_CLOEXEC)
> > +static int fuse_pipe(int fds[2])
> > +{
> > +   int rv = pipe(fds);
> > +
> > +   if (rv == -1)
> > +           return rv;
> > +
> > +   if (fcntl(fds[0], F_SETFL, O_NONBLOCK) == -1 ||
> > +       fcntl(fds[1], F_SETFL, O_NONBLOCK) == -1 ||
> > +       fcntl(fds[0], F_SETFD, FD_CLOEXEC) == -1 ||
> > +       fcntl(fds[1], F_SETFD, FD_CLOEXEC) == -1) {
> > +           close(fds[0]);
> > +           close(fds[1]);
> > +           rv = -1;
> > +   }
> > +   return rv;
> > +}
> > +#else
> > +static int fuse_pipe(int fds[2])
> > +{
> > +   return pipe2(fds, O_CLOEXEC | O_NONBLOCK);
> > +}
> > +#endif
> > +
> > +static struct fuse_ll_pipe *fuse_ll_get_pipe(struct fuse_session *se)
> > +{
> > +   struct fuse_ll_pipe *llp = pthread_getspecific(se->pipe_key);
> > +   if (llp == NULL) {
> > +           int res;
> > +
> > +           llp = malloc(sizeof(struct fuse_ll_pipe));
> > +           if (llp == NULL)
> > +                   return NULL;
> > +
> > +           res = fuse_pipe(llp->pipe);
> > +           if (res == -1) {
> > +                   free(llp);
> > +                   return NULL;
> > +           }
> > +
> > +           /*
> > +            *the default size is 16 pages on linux
> > +            */
> > +           llp->size = pagesize * 16;
> > +           llp->can_grow = 1;
> > +
> > +           pthread_setspecific(se->pipe_key, llp);
> > +   }
> > +
> > +   return llp;
> > +}
> > +#endif
> > +
> > +static void fuse_ll_clear_pipe(struct fuse_session *se)
> > +{
> > +   struct fuse_ll_pipe *llp = pthread_getspecific(se->pipe_key);
> > +   if (llp) {
> > +           pthread_setspecific(se->pipe_key, NULL);
> > +           fuse_ll_pipe_free(llp);
> > +   }
> > +}
> > +
> > +#if defined(HAVE_SPLICE) && defined(HAVE_VMSPLICE)
> > +static int read_back(int fd, char *buf, size_t len)
> > +{
> > +   int res;
> > +
> > +   res = read(fd, buf, len);
> > +   if (res == -1) {
> > +           fuse_log(FUSE_LOG_ERR, "fuse: internal error: failed to read 
> > back from pipe: %s\n", strerror(errno));
> > +           return -EIO;
> > +   }
> > +   if (res != len) {
> > +           fuse_log(FUSE_LOG_ERR, "fuse: internal error: short read back 
> > from pipe: %i from %zi\n", res, len);
> > +           return -EIO;
> > +   }
> > +   return 0;
> > +}
> > +
> > +static int grow_pipe_to_max(int pipefd)
> > +{
> > +   int max;
> > +   int res;
> > +   int maxfd;
> > +   char buf[32];
> > +
> > +   maxfd = open("/proc/sys/fs/pipe-max-size", O_RDONLY);
> > +   if (maxfd < 0)
> > +           return -errno;
> > +
> > +   res = read(maxfd, buf, sizeof(buf) - 1);
> > +   if (res < 0) {
> > +           int saved_errno;
> > +
> > +           saved_errno = errno;
> > +           close(maxfd);
> > +           return -saved_errno;
> > +   }
> > +   close(maxfd);
> > +   buf[res] = '\0';
> > +
> > +   max = atoi(buf);
> > +   res = fcntl(pipefd, F_SETPIPE_SZ, max);
> > +   if (res < 0)
> > +           return -errno;
> > +   return max;
> > +}
> > +
> > +static int fuse_send_data_iov(struct fuse_session *se, struct fuse_chan 
> > *ch,
> > +                          struct iovec *iov, int iov_count,
> > +                          struct fuse_bufvec *buf, unsigned int flags)
> > +{
> > +   int res;
> > +   size_t len = fuse_buf_size(buf);
> > +   struct fuse_out_header *out = iov[0].iov_base;
> > +   struct fuse_ll_pipe *llp;
> > +   int splice_flags;
> > +   size_t pipesize;
> > +   size_t total_fd_size;
> > +   size_t idx;
> > +   size_t headerlen;
> > +   struct fuse_bufvec pipe_buf = FUSE_BUFVEC_INIT(len);
> > +
> > +   if (se->broken_splice_nonblock)
> > +           goto fallback;
> > +
> > +   if (flags & FUSE_BUF_NO_SPLICE)
> > +           goto fallback;
> > +
> > +   total_fd_size = 0;
> > +   for (idx = buf->idx; idx < buf->count; idx++) {
> > +           if (buf->buf[idx].flags & FUSE_BUF_IS_FD) {
> > +                   total_fd_size = buf->buf[idx].size;
> > +                   if (idx == buf->idx)
> > +                           total_fd_size -= buf->off;
> > +           }
> > +   }
> > +   if (total_fd_size < 2 * pagesize)
> > +           goto fallback;
> > +
> > +   if (se->conn.proto_minor < 14 ||
> > +       !(se->conn.want & FUSE_CAP_SPLICE_WRITE))
> > +           goto fallback;
> > +
> > +   llp = fuse_ll_get_pipe(se);
> > +   if (llp == NULL)
> > +           goto fallback;
> > +
> > +
> > +   headerlen = iov_length(iov, iov_count);
> > +
> > +   out->len = headerlen + len;
> > +
> > +   /*
> > +    * Heuristic for the required pipe size, does not work if the
> > +    * source contains less than page size fragments
> > +    */
> > +   pipesize = pagesize * (iov_count + buf->count + 1) + out->len;
> > +
> > +   if (llp->size < pipesize) {
> > +           if (llp->can_grow) {
> > +                   res = fcntl(llp->pipe[0], F_SETPIPE_SZ, pipesize);
> > +                   if (res == -1) {
> > +                           res = grow_pipe_to_max(llp->pipe[0]);
> > +                           if (res > 0)
> > +                                   llp->size = res;
> > +                           llp->can_grow = 0;
> > +                           goto fallback;
> > +                   }
> > +                   llp->size = res;
> > +           }
> > +           if (llp->size < pipesize)
> > +                   goto fallback;
> > +   }
> > +
> > +
> > +   res = vmsplice(llp->pipe[1], iov, iov_count, SPLICE_F_NONBLOCK);
> > +   if (res == -1)
> > +           goto fallback;
> > +
> > +   if (res != headerlen) {
> > +           res = -EIO;
> > +           fuse_log(FUSE_LOG_ERR, "fuse: short vmsplice to pipe: 
> > %u/%zu\n", res,
> > +                   headerlen);
> > +           goto clear_pipe;
> > +   }
> > +
> > +   pipe_buf.buf[0].flags = FUSE_BUF_IS_FD;
> > +   pipe_buf.buf[0].fd = llp->pipe[1];
> > +
> > +   res = fuse_buf_copy(&pipe_buf, buf,
> > +                       FUSE_BUF_FORCE_SPLICE | FUSE_BUF_SPLICE_NONBLOCK);
> > +   if (res < 0) {
> > +           if (res == -EAGAIN || res == -EINVAL) {
> > +                   /*
> > +                    * Should only get EAGAIN on kernels with
> > +                    * broken SPLICE_F_NONBLOCK support (<=
> > +                    * 2.6.35) where this error or a short read is
> > +                    * returned even if the pipe itself is not
> > +                    * full
> > +                    *
> > +                    * EINVAL might mean that splice can't handle
> > +                    * this combination of input and output.
> > +                    */
> > +                   if (res == -EAGAIN)
> > +                           se->broken_splice_nonblock = 1;
> > +
> > +                   pthread_setspecific(se->pipe_key, NULL);
> > +                   fuse_ll_pipe_free(llp);
> > +                   goto fallback;
> > +           }
> > +           res = -res;
> > +           goto clear_pipe;
> > +   }
> > +
> > +   if (res != 0 && res < len) {
> > +           struct fuse_bufvec mem_buf = FUSE_BUFVEC_INIT(len);
> > +           void *mbuf;
> > +           size_t now_len = res;
> > +           /*
> > +            * For regular files a short count is either
> > +            *  1) due to EOF, or
> > +            *  2) because of broken SPLICE_F_NONBLOCK (see above)
> > +            *
> > +            * For other inputs it's possible that we overflowed
> > +            * the pipe because of small buffer fragments.
> > +            */
> > +
> > +           res = posix_memalign(&mbuf, pagesize, len);
> > +           if (res != 0)
> > +                   goto clear_pipe;
> > +
> > +           mem_buf.buf[0].mem = mbuf;
> > +           mem_buf.off = now_len;
> > +           res = fuse_buf_copy(&mem_buf, buf, 0);
> > +           if (res > 0) {
> > +                   char *tmpbuf;
> > +                   size_t extra_len = res;
> > +                   /*
> > +                    * Trickiest case: got more data.  Need to get
> > +                    * back the data from the pipe and then fall
> > +                    * back to regular write.
> > +                    */
> > +                   tmpbuf = malloc(headerlen);
> > +                   if (tmpbuf == NULL) {
> > +                           free(mbuf);
> > +                           res = ENOMEM;
> > +                           goto clear_pipe;
> > +                   }
> > +                   res = read_back(llp->pipe[0], tmpbuf, headerlen);
> > +                   free(tmpbuf);
> > +                   if (res != 0) {
> > +                           free(mbuf);
> > +                           goto clear_pipe;
> > +                   }
> > +                   res = read_back(llp->pipe[0], mbuf, now_len);
> > +                   if (res != 0) {
> > +                           free(mbuf);
> > +                           goto clear_pipe;
> > +                   }
> > +                   len = now_len + extra_len;
> > +                   iov[iov_count].iov_base = mbuf;
> > +                   iov[iov_count].iov_len = len;
> > +                   iov_count++;
> > +                   res = fuse_send_msg(se, ch, iov, iov_count);
> > +                   free(mbuf);
> > +                   return res;
> > +           }
> > +           free(mbuf);
> > +           res = now_len;
> > +   }
> > +   len = res;
> > +   out->len = headerlen + len;
> > +
> > +   if (se->debug) {
> > +           fuse_log(FUSE_LOG_DEBUG,
> > +                   "   unique: %llu, success, outsize: %i (splice)\n",
> > +                   (unsigned long long) out->unique, out->len);
> > +   }
> > +
> > +   splice_flags = 0;
> > +   if ((flags & FUSE_BUF_SPLICE_MOVE) &&
> > +       (se->conn.want & FUSE_CAP_SPLICE_MOVE))
> > +           splice_flags |= SPLICE_F_MOVE;
> > +
> > +   res = splice(llp->pipe[0], NULL, ch ? ch->fd : se->fd,
> > +                NULL, out->len, splice_flags);
> > +   if (res == -1) {
> > +           res = -errno;
> > +           perror("fuse: splice from pipe");
> > +           goto clear_pipe;
> > +   }
> > +   if (res != out->len) {
> > +           res = -EIO;
> > +           fuse_log(FUSE_LOG_ERR, "fuse: short splice from pipe: %u/%u\n",
> > +                   res, out->len);
> > +           goto clear_pipe;
> > +   }
> > +   return 0;
> > +
> > +clear_pipe:
> > +   fuse_ll_clear_pipe(se);
> > +   return res;
> > +
> > +fallback:
> > +   return fuse_send_data_iov_fallback(se, ch, iov, iov_count, buf, len);
> > +}
> > +#else
> > +static int fuse_send_data_iov(struct fuse_session *se, struct fuse_chan 
> > *ch,
> > +                          struct iovec *iov, int iov_count,
> > +                          struct fuse_bufvec *buf, unsigned int flags)
> > +{
> > +   size_t len = fuse_buf_size(buf);
> > +   (void) flags;
> > +
> > +   return fuse_send_data_iov_fallback(se, ch, iov, iov_count, buf, len);
> > +}
> > +#endif
> > +
> > +int fuse_reply_data(fuse_req_t req, struct fuse_bufvec *bufv,
> > +               enum fuse_buf_copy_flags flags)
> > +{
> > +   struct iovec iov[2];
> > +   struct fuse_out_header out;
> > +   int res;
> > +
> > +   iov[0].iov_base = &out;
> > +   iov[0].iov_len = sizeof(struct fuse_out_header);
> > +
> > +   out.unique = req->unique;
> > +   out.error = 0;
> > +
> > +   res = fuse_send_data_iov(req->se, req->ch, iov, 1, bufv, flags);
> > +   if (res <= 0) {
> > +           fuse_free_req(req);
> > +           return res;
> > +   } else {
> > +           return fuse_reply_err(req, res);
> > +   }
> > +}
> > +
> > +int fuse_reply_statfs(fuse_req_t req, const struct statvfs *stbuf)
> > +{
> > +   struct fuse_statfs_out arg;
> > +   size_t size = req->se->conn.proto_minor < 4 ?
> > +           FUSE_COMPAT_STATFS_SIZE : sizeof(arg);
> > +
> > +   memset(&arg, 0, sizeof(arg));
> > +   convert_statfs(stbuf, &arg.st);
> > +
> > +   return send_reply_ok(req, &arg, size);
> > +}
> > +
> > +int fuse_reply_xattr(fuse_req_t req, size_t count)
> > +{
> > +   struct fuse_getxattr_out arg;
> > +
> > +   memset(&arg, 0, sizeof(arg));
> > +   arg.size = count;
> > +
> > +   return send_reply_ok(req, &arg, sizeof(arg));
> > +}
> > +
> > +int fuse_reply_lock(fuse_req_t req, const struct flock *lock)
> > +{
> > +   struct fuse_lk_out arg;
> > +
> > +   memset(&arg, 0, sizeof(arg));
> > +   arg.lk.type = lock->l_type;
> > +   if (lock->l_type != F_UNLCK) {
> > +           arg.lk.start = lock->l_start;
> > +           if (lock->l_len == 0)
> > +                   arg.lk.end = OFFSET_MAX;
> > +           else
> > +                   arg.lk.end = lock->l_start + lock->l_len - 1;
> > +   }
> > +   arg.lk.pid = lock->l_pid;
> > +   return send_reply_ok(req, &arg, sizeof(arg));
> > +}
> > +
> > +int fuse_reply_bmap(fuse_req_t req, uint64_t idx)
> > +{
> > +   struct fuse_bmap_out arg;
> > +
> > +   memset(&arg, 0, sizeof(arg));
> > +   arg.block = idx;
> > +
> > +   return send_reply_ok(req, &arg, sizeof(arg));
> > +}
> > +
> > +static struct fuse_ioctl_iovec *fuse_ioctl_iovec_copy(const struct iovec 
> > *iov,
> > +                                                 size_t count)
> > +{
> > +   struct fuse_ioctl_iovec *fiov;
> > +   size_t i;
> > +
> > +   fiov = malloc(sizeof(fiov[0]) * count);
> > +   if (!fiov)
> > +           return NULL;
> > +
> > +   for (i = 0; i < count; i++) {
> > +           fiov[i].base = (uintptr_t) iov[i].iov_base;
> > +           fiov[i].len = iov[i].iov_len;
> > +   }
> > +
> > +   return fiov;
> > +}
> > +
> > +int fuse_reply_ioctl_retry(fuse_req_t req,
> > +                      const struct iovec *in_iov, size_t in_count,
> > +                      const struct iovec *out_iov, size_t out_count)
> > +{
> > +   struct fuse_ioctl_out arg;
> > +   struct fuse_ioctl_iovec *in_fiov = NULL;
> > +   struct fuse_ioctl_iovec *out_fiov = NULL;
> > +   struct iovec iov[4];
> > +   size_t count = 1;
> > +   int res;
> > +
> > +   memset(&arg, 0, sizeof(arg));
> > +   arg.flags |= FUSE_IOCTL_RETRY;
> > +   arg.in_iovs = in_count;
> > +   arg.out_iovs = out_count;
> > +   iov[count].iov_base = &arg;
> > +   iov[count].iov_len = sizeof(arg);
> > +   count++;
> > +
> > +   if (req->se->conn.proto_minor < 16) {
> > +           if (in_count) {
> > +                   iov[count].iov_base = (void *)in_iov;
> > +                   iov[count].iov_len = sizeof(in_iov[0]) * in_count;
> > +                   count++;
> > +           }
> > +
> > +           if (out_count) {
> > +                   iov[count].iov_base = (void *)out_iov;
> > +                   iov[count].iov_len = sizeof(out_iov[0]) * out_count;
> > +                   count++;
> > +           }
> > +   } else {
> > +           /* Can't handle non-compat 64bit ioctls on 32bit */
> > +           if (sizeof(void *) == 4 && req->ioctl_64bit) {
> > +                   res = fuse_reply_err(req, EINVAL);
> > +                   goto out;
> > +           }
> > +
> > +           if (in_count) {
> > +                   in_fiov = fuse_ioctl_iovec_copy(in_iov, in_count);
> > +                   if (!in_fiov)
> > +                           goto enomem;
> > +
> > +                   iov[count].iov_base = (void *)in_fiov;
> > +                   iov[count].iov_len = sizeof(in_fiov[0]) * in_count;
> > +                   count++;
> > +           }
> > +           if (out_count) {
> > +                   out_fiov = fuse_ioctl_iovec_copy(out_iov, out_count);
> > +                   if (!out_fiov)
> > +                           goto enomem;
> > +
> > +                   iov[count].iov_base = (void *)out_fiov;
> > +                   iov[count].iov_len = sizeof(out_fiov[0]) * out_count;
> > +                   count++;
> > +           }
> > +   }
> > +
> > +   res = send_reply_iov(req, 0, iov, count);
> > +out:
> > +   free(in_fiov);
> > +   free(out_fiov);
> > +
> > +   return res;
> > +
> > +enomem:
> > +   res = fuse_reply_err(req, ENOMEM);
> > +   goto out;
> > +}
> > +
> > +int fuse_reply_ioctl(fuse_req_t req, int result, const void *buf, size_t 
> > size)
> > +{
> > +   struct fuse_ioctl_out arg;
> > +   struct iovec iov[3];
> > +   size_t count = 1;
> > +
> > +   memset(&arg, 0, sizeof(arg));
> > +   arg.result = result;
> > +   iov[count].iov_base = &arg;
> > +   iov[count].iov_len = sizeof(arg);
> > +   count++;
> > +
> > +   if (size) {
> > +           iov[count].iov_base = (char *) buf;
> > +           iov[count].iov_len = size;
> > +           count++;
> > +   }
> > +
> > +   return send_reply_iov(req, 0, iov, count);
> > +}
> > +
> > +int fuse_reply_ioctl_iov(fuse_req_t req, int result, const struct iovec 
> > *iov,
> > +                    int count)
> > +{
> > +   struct iovec *padded_iov;
> > +   struct fuse_ioctl_out arg;
> > +   int res;
> > +
> > +   padded_iov = malloc((count + 2) * sizeof(struct iovec));
> > +   if (padded_iov == NULL)
> > +           return fuse_reply_err(req, ENOMEM);
> > +
> > +   memset(&arg, 0, sizeof(arg));
> > +   arg.result = result;
> > +   padded_iov[1].iov_base = &arg;
> > +   padded_iov[1].iov_len = sizeof(arg);
> > +
> > +   memcpy(&padded_iov[2], iov, count * sizeof(struct iovec));
> > +
> > +   res = send_reply_iov(req, 0, padded_iov, count + 2);
> > +   free(padded_iov);
> > +
> > +   return res;
> > +}
> > +
> > +int fuse_reply_poll(fuse_req_t req, unsigned revents)
> > +{
> > +   struct fuse_poll_out arg;
> > +
> > +   memset(&arg, 0, sizeof(arg));
> > +   arg.revents = revents;
> > +
> > +   return send_reply_ok(req, &arg, sizeof(arg));
> > +}
> > +
> > +static void do_lookup(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   char *name = (char *) inarg;
> > +
> > +   if (req->se->op.lookup)
> > +           req->se->op.lookup(req, nodeid, name);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_forget(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   struct fuse_forget_in *arg = (struct fuse_forget_in *) inarg;
> > +
> > +   if (req->se->op.forget)
> > +           req->se->op.forget(req, nodeid, arg->nlookup);
> > +   else
> > +           fuse_reply_none(req);
> > +}
> > +
> > +static void do_batch_forget(fuse_req_t req, fuse_ino_t nodeid,
> > +                       const void *inarg)
> > +{
> > +   struct fuse_batch_forget_in *arg = (void *) inarg;
> > +   struct fuse_forget_one *param = (void *) PARAM(arg);
> > +   unsigned int i;
> > +
> > +   (void) nodeid;
> > +
> > +   if (req->se->op.forget_multi) {
> > +           req->se->op.forget_multi(req, arg->count,
> > +                                (struct fuse_forget_data *) param);
> > +   } else if (req->se->op.forget) {
> > +           for (i = 0; i < arg->count; i++) {
> > +                   struct fuse_forget_one *forget = &param[i];
> > +                   struct fuse_req *dummy_req;
> > +
> > +                   dummy_req = fuse_ll_alloc_req(req->se);
> > +                   if (dummy_req == NULL)
> > +                           break;
> > +
> > +                   dummy_req->unique = req->unique;
> > +                   dummy_req->ctx = req->ctx;
> > +                   dummy_req->ch = NULL;
> > +
> > +                   req->se->op.forget(dummy_req, forget->nodeid,
> > +                                     forget->nlookup);
> > +           }
> > +           fuse_reply_none(req);
> > +   } else {
> > +           fuse_reply_none(req);
> > +   }
> > +}
> > +
> > +static void do_getattr(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   struct fuse_file_info *fip = NULL;
> > +   struct fuse_file_info fi;
> > +
> > +   if (req->se->conn.proto_minor >= 9) {
> > +           struct fuse_getattr_in *arg = (struct fuse_getattr_in *) inarg;
> > +
> > +           if (arg->getattr_flags & FUSE_GETATTR_FH) {
> > +                   memset(&fi, 0, sizeof(fi));
> > +                   fi.fh = arg->fh;
> > +                   fip = &fi;
> > +           }
> > +   }
> > +
> > +   if (req->se->op.getattr)
> > +           req->se->op.getattr(req, nodeid, fip);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_setattr(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   struct fuse_setattr_in *arg = (struct fuse_setattr_in *) inarg;
> > +
> > +   if (req->se->op.setattr) {
> > +           struct fuse_file_info *fi = NULL;
> > +           struct fuse_file_info fi_store;
> > +           struct stat stbuf;
> > +           memset(&stbuf, 0, sizeof(stbuf));
> > +           convert_attr(arg, &stbuf);
> > +           if (arg->valid & FATTR_FH) {
> > +                   arg->valid &= ~FATTR_FH;
> > +                   memset(&fi_store, 0, sizeof(fi_store));
> > +                   fi = &fi_store;
> > +                   fi->fh = arg->fh;
> > +           }
> > +           arg->valid &=
> > +                   FUSE_SET_ATTR_MODE      |
> > +                   FUSE_SET_ATTR_UID       |
> > +                   FUSE_SET_ATTR_GID       |
> > +                   FUSE_SET_ATTR_SIZE      |
> > +                   FUSE_SET_ATTR_ATIME     |
> > +                   FUSE_SET_ATTR_MTIME     |
> > +                   FUSE_SET_ATTR_ATIME_NOW |
> > +                   FUSE_SET_ATTR_MTIME_NOW |
> > +                   FUSE_SET_ATTR_CTIME;
> > +
> > +           req->se->op.setattr(req, nodeid, &stbuf, arg->valid, fi);
> > +   } else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_access(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   struct fuse_access_in *arg = (struct fuse_access_in *) inarg;
> > +
> > +   if (req->se->op.access)
> > +           req->se->op.access(req, nodeid, arg->mask);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_readlink(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   (void) inarg;
> > +
> > +   if (req->se->op.readlink)
> > +           req->se->op.readlink(req, nodeid);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_mknod(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   struct fuse_mknod_in *arg = (struct fuse_mknod_in *) inarg;
> > +   char *name = PARAM(arg);
> > +
> > +   if (req->se->conn.proto_minor >= 12)
> > +           req->ctx.umask = arg->umask;
> > +   else
> > +           name = (char *) inarg + FUSE_COMPAT_MKNOD_IN_SIZE;
> > +
> > +   if (req->se->op.mknod)
> > +           req->se->op.mknod(req, nodeid, name, arg->mode, arg->rdev);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_mkdir(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   struct fuse_mkdir_in *arg = (struct fuse_mkdir_in *) inarg;
> > +
> > +   if (req->se->conn.proto_minor >= 12)
> > +           req->ctx.umask = arg->umask;
> > +
> > +   if (req->se->op.mkdir)
> > +           req->se->op.mkdir(req, nodeid, PARAM(arg), arg->mode);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_unlink(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   char *name = (char *) inarg;
> > +
> > +   if (req->se->op.unlink)
> > +           req->se->op.unlink(req, nodeid, name);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_rmdir(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   char *name = (char *) inarg;
> > +
> > +   if (req->se->op.rmdir)
> > +           req->se->op.rmdir(req, nodeid, name);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_symlink(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   char *name = (char *) inarg;
> > +   char *linkname = ((char *) inarg) + strlen((char *) inarg) + 1;
> > +
> > +   if (req->se->op.symlink)
> > +           req->se->op.symlink(req, linkname, nodeid, name);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_rename(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   struct fuse_rename_in *arg = (struct fuse_rename_in *) inarg;
> > +   char *oldname = PARAM(arg);
> > +   char *newname = oldname + strlen(oldname) + 1;
> > +
> > +   if (req->se->op.rename)
> > +           req->se->op.rename(req, nodeid, oldname, arg->newdir, newname,
> > +                             0);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_rename2(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   struct fuse_rename2_in *arg = (struct fuse_rename2_in *) inarg;
> > +   char *oldname = PARAM(arg);
> > +   char *newname = oldname + strlen(oldname) + 1;
> > +
> > +   if (req->se->op.rename)
> > +           req->se->op.rename(req, nodeid, oldname, arg->newdir, newname,
> > +                             arg->flags);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_link(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   struct fuse_link_in *arg = (struct fuse_link_in *) inarg;
> > +
> > +   if (req->se->op.link)
> > +           req->se->op.link(req, arg->oldnodeid, nodeid, PARAM(arg));
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_create(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   struct fuse_create_in *arg = (struct fuse_create_in *) inarg;
> > +
> > +   if (req->se->op.create) {
> > +           struct fuse_file_info fi;
> > +           char *name = PARAM(arg);
> > +
> > +           memset(&fi, 0, sizeof(fi));
> > +           fi.flags = arg->flags;
> > +
> > +           if (req->se->conn.proto_minor >= 12)
> > +                   req->ctx.umask = arg->umask;
> > +           else
> > +                   name = (char *) inarg + sizeof(struct fuse_open_in);
> > +
> > +           req->se->op.create(req, nodeid, name, arg->mode, &fi);
> > +   } else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_open(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   struct fuse_open_in *arg = (struct fuse_open_in *) inarg;
> > +   struct fuse_file_info fi;
> > +
> > +   memset(&fi, 0, sizeof(fi));
> > +   fi.flags = arg->flags;
> > +
> > +   if (req->se->op.open)
> > +           req->se->op.open(req, nodeid, &fi);
> > +   else
> > +           fuse_reply_open(req, &fi);
> > +}
> > +
> > +static void do_read(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   struct fuse_read_in *arg = (struct fuse_read_in *) inarg;
> > +
> > +   if (req->se->op.read) {
> > +           struct fuse_file_info fi;
> > +
> > +           memset(&fi, 0, sizeof(fi));
> > +           fi.fh = arg->fh;
> > +           if (req->se->conn.proto_minor >= 9) {
> > +                   fi.lock_owner = arg->lock_owner;
> > +                   fi.flags = arg->flags;
> > +           }
> > +           req->se->op.read(req, nodeid, arg->size, arg->offset, &fi);
> > +   } else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_write(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   struct fuse_write_in *arg = (struct fuse_write_in *) inarg;
> > +   struct fuse_file_info fi;
> > +   char *param;
> > +
> > +   memset(&fi, 0, sizeof(fi));
> > +   fi.fh = arg->fh;
> > +   fi.writepage = (arg->write_flags & FUSE_WRITE_CACHE) != 0;
> > +
> > +   if (req->se->conn.proto_minor < 9) {
> > +           param = ((char *) arg) + FUSE_COMPAT_WRITE_IN_SIZE;
> > +   } else {
> > +           fi.lock_owner = arg->lock_owner;
> > +           fi.flags = arg->flags;
> > +           param = PARAM(arg);
> > +   }
> > +
> > +   if (req->se->op.write)
> > +           req->se->op.write(req, nodeid, param, arg->size,
> > +                            arg->offset, &fi);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_write_buf(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg,
> > +                    const struct fuse_buf *ibuf)
> > +{
> > +   struct fuse_session *se = req->se;
> > +   struct fuse_bufvec bufv = {
> > +           .buf[0] = *ibuf,
> > +           .count = 1,
> > +   };
> > +   struct fuse_write_in *arg = (struct fuse_write_in *) inarg;
> > +   struct fuse_file_info fi;
> > +
> > +   memset(&fi, 0, sizeof(fi));
> > +   fi.fh = arg->fh;
> > +   fi.writepage = arg->write_flags & FUSE_WRITE_CACHE;
> > +
> > +   if (se->conn.proto_minor < 9) {
> > +           bufv.buf[0].mem = ((char *) arg) + FUSE_COMPAT_WRITE_IN_SIZE;
> > +           bufv.buf[0].size -= sizeof(struct fuse_in_header) +
> > +                   FUSE_COMPAT_WRITE_IN_SIZE;
> > +           assert(!(bufv.buf[0].flags & FUSE_BUF_IS_FD));
> > +   } else {
> > +           fi.lock_owner = arg->lock_owner;
> > +           fi.flags = arg->flags;
> > +           if (!(bufv.buf[0].flags & FUSE_BUF_IS_FD))
> > +                   bufv.buf[0].mem = PARAM(arg);
> > +
> > +           bufv.buf[0].size -= sizeof(struct fuse_in_header) +
> > +                   sizeof(struct fuse_write_in);
> > +   }
> > +   if (bufv.buf[0].size < arg->size) {
> > +           fuse_log(FUSE_LOG_ERR, "fuse: do_write_buf: buffer size too 
> > small\n");
> > +           fuse_reply_err(req, EIO);
> > +           goto out;
> > +   }
> > +   bufv.buf[0].size = arg->size;
> > +
> > +   se->op.write_buf(req, nodeid, &bufv, arg->offset, &fi);
> > +
> > +out:
> > +   /* Need to reset the pipe if ->write_buf() didn't consume all data */
> > +   if ((ibuf->flags & FUSE_BUF_IS_FD) && bufv.idx < bufv.count)
> > +           fuse_ll_clear_pipe(se);
> > +}
> > +
> > +static void do_flush(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   struct fuse_flush_in *arg = (struct fuse_flush_in *) inarg;
> > +   struct fuse_file_info fi;
> > +
> > +   memset(&fi, 0, sizeof(fi));
> > +   fi.fh = arg->fh;
> > +   fi.flush = 1;
> > +   if (req->se->conn.proto_minor >= 7)
> > +           fi.lock_owner = arg->lock_owner;
> > +
> > +   if (req->se->op.flush)
> > +           req->se->op.flush(req, nodeid, &fi);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_release(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   struct fuse_release_in *arg = (struct fuse_release_in *) inarg;
> > +   struct fuse_file_info fi;
> > +
> > +   memset(&fi, 0, sizeof(fi));
> > +   fi.flags = arg->flags;
> > +   fi.fh = arg->fh;
> > +   if (req->se->conn.proto_minor >= 8) {
> > +           fi.flush = (arg->release_flags & FUSE_RELEASE_FLUSH) ? 1 : 0;
> > +           fi.lock_owner = arg->lock_owner;
> > +   }
> > +   if (arg->release_flags & FUSE_RELEASE_FLOCK_UNLOCK) {
> > +           fi.flock_release = 1;
> > +           fi.lock_owner = arg->lock_owner;
> > +   }
> > +
> > +   if (req->se->op.release)
> > +           req->se->op.release(req, nodeid, &fi);
> > +   else
> > +           fuse_reply_err(req, 0);
> > +}
> > +
> > +static void do_fsync(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   struct fuse_fsync_in *arg = (struct fuse_fsync_in *) inarg;
> > +   struct fuse_file_info fi;
> > +   int datasync = arg->fsync_flags & 1;
> > +
> > +   memset(&fi, 0, sizeof(fi));
> > +   fi.fh = arg->fh;
> > +
> > +   if (req->se->op.fsync)
> > +           req->se->op.fsync(req, nodeid, datasync, &fi);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_opendir(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   struct fuse_open_in *arg = (struct fuse_open_in *) inarg;
> > +   struct fuse_file_info fi;
> > +
> > +   memset(&fi, 0, sizeof(fi));
> > +   fi.flags = arg->flags;
> > +
> > +   if (req->se->op.opendir)
> > +           req->se->op.opendir(req, nodeid, &fi);
> > +   else
> > +           fuse_reply_open(req, &fi);
> > +}
> > +
> > +static void do_readdir(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   struct fuse_read_in *arg = (struct fuse_read_in *) inarg;
> > +   struct fuse_file_info fi;
> > +
> > +   memset(&fi, 0, sizeof(fi));
> > +   fi.fh = arg->fh;
> > +
> > +   if (req->se->op.readdir)
> > +           req->se->op.readdir(req, nodeid, arg->size, arg->offset, &fi);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_readdirplus(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   struct fuse_read_in *arg = (struct fuse_read_in *) inarg;
> > +   struct fuse_file_info fi;
> > +
> > +   memset(&fi, 0, sizeof(fi));
> > +   fi.fh = arg->fh;
> > +
> > +   if (req->se->op.readdirplus)
> > +           req->se->op.readdirplus(req, nodeid, arg->size, arg->offset, 
> > &fi);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_releasedir(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   struct fuse_release_in *arg = (struct fuse_release_in *) inarg;
> > +   struct fuse_file_info fi;
> > +
> > +   memset(&fi, 0, sizeof(fi));
> > +   fi.flags = arg->flags;
> > +   fi.fh = arg->fh;
> > +
> > +   if (req->se->op.releasedir)
> > +           req->se->op.releasedir(req, nodeid, &fi);
> > +   else
> > +           fuse_reply_err(req, 0);
> > +}
> > +
> > +static void do_fsyncdir(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   struct fuse_fsync_in *arg = (struct fuse_fsync_in *) inarg;
> > +   struct fuse_file_info fi;
> > +   int datasync = arg->fsync_flags & 1;
> > +
> > +   memset(&fi, 0, sizeof(fi));
> > +   fi.fh = arg->fh;
> > +
> > +   if (req->se->op.fsyncdir)
> > +           req->se->op.fsyncdir(req, nodeid, datasync, &fi);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_statfs(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   (void) nodeid;
> > +   (void) inarg;
> > +
> > +   if (req->se->op.statfs)
> > +           req->se->op.statfs(req, nodeid);
> > +   else {
> > +           struct statvfs buf = {
> > +                   .f_namemax = 255,
> > +                   .f_bsize = 512,
> > +           };
> > +           fuse_reply_statfs(req, &buf);
> > +   }
> > +}
> > +
> > +static void do_setxattr(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   struct fuse_setxattr_in *arg = (struct fuse_setxattr_in *) inarg;
> > +   char *name = PARAM(arg);
> > +   char *value = name + strlen(name) + 1;
> > +
> > +   if (req->se->op.setxattr)
> > +           req->se->op.setxattr(req, nodeid, name, value, arg->size,
> > +                               arg->flags);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_getxattr(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   struct fuse_getxattr_in *arg = (struct fuse_getxattr_in *) inarg;
> > +
> > +   if (req->se->op.getxattr)
> > +           req->se->op.getxattr(req, nodeid, PARAM(arg), arg->size);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_listxattr(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   struct fuse_getxattr_in *arg = (struct fuse_getxattr_in *) inarg;
> > +
> > +   if (req->se->op.listxattr)
> > +           req->se->op.listxattr(req, nodeid, arg->size);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_removexattr(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   char *name = (char *) inarg;
> > +
> > +   if (req->se->op.removexattr)
> > +           req->se->op.removexattr(req, nodeid, name);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void convert_fuse_file_lock(struct fuse_file_lock *fl,
> > +                              struct flock *flock)
> > +{
> > +   memset(flock, 0, sizeof(struct flock));
> > +   flock->l_type = fl->type;
> > +   flock->l_whence = SEEK_SET;
> > +   flock->l_start = fl->start;
> > +   if (fl->end == OFFSET_MAX)
> > +           flock->l_len = 0;
> > +   else
> > +           flock->l_len = fl->end - fl->start + 1;
> > +   flock->l_pid = fl->pid;
> > +}
> > +
> > +static void do_getlk(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   struct fuse_lk_in *arg = (struct fuse_lk_in *) inarg;
> > +   struct fuse_file_info fi;
> > +   struct flock flock;
> > +
> > +   memset(&fi, 0, sizeof(fi));
> > +   fi.fh = arg->fh;
> > +   fi.lock_owner = arg->owner;
> > +
> > +   convert_fuse_file_lock(&arg->lk, &flock);
> > +   if (req->se->op.getlk)
> > +           req->se->op.getlk(req, nodeid, &fi, &flock);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_setlk_common(fuse_req_t req, fuse_ino_t nodeid,
> > +                       const void *inarg, int sleep)
> > +{
> > +   struct fuse_lk_in *arg = (struct fuse_lk_in *) inarg;
> > +   struct fuse_file_info fi;
> > +   struct flock flock;
> > +
> > +   memset(&fi, 0, sizeof(fi));
> > +   fi.fh = arg->fh;
> > +   fi.lock_owner = arg->owner;
> > +
> > +   if (arg->lk_flags & FUSE_LK_FLOCK) {
> > +           int op = 0;
> > +
> > +           switch (arg->lk.type) {
> > +           case F_RDLCK:
> > +                   op = LOCK_SH;
> > +                   break;
> > +           case F_WRLCK:
> > +                   op = LOCK_EX;
> > +                   break;
> > +           case F_UNLCK:
> > +                   op = LOCK_UN;
> > +                   break;
> > +           }
> > +           if (!sleep)
> > +                   op |= LOCK_NB;
> > +
> > +           if (req->se->op.flock)
> > +                   req->se->op.flock(req, nodeid, &fi, op);
> > +           else
> > +                   fuse_reply_err(req, ENOSYS);
> > +   } else {
> > +           convert_fuse_file_lock(&arg->lk, &flock);
> > +           if (req->se->op.setlk)
> > +                   req->se->op.setlk(req, nodeid, &fi, &flock, sleep);
> > +           else
> > +                   fuse_reply_err(req, ENOSYS);
> > +   }
> > +}
> > +
> > +static void do_setlk(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   do_setlk_common(req, nodeid, inarg, 0);
> > +}
> > +
> > +static void do_setlkw(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   do_setlk_common(req, nodeid, inarg, 1);
> > +}
> > +
> > +static int find_interrupted(struct fuse_session *se, struct fuse_req *req)
> > +{
> > +   struct fuse_req *curr;
> > +
> > +   for (curr = se->list.next; curr != &se->list; curr = curr->next) {
> > +           if (curr->unique == req->u.i.unique) {
> > +                   fuse_interrupt_func_t func;
> > +                   void *data;
> > +
> > +                   curr->ctr++;
> > +                   pthread_mutex_unlock(&se->lock);
> > +
> > +                   /* Ugh, ugly locking */
> > +                   pthread_mutex_lock(&curr->lock);
> > +                   pthread_mutex_lock(&se->lock);
> > +                   curr->interrupted = 1;
> > +                   func = curr->u.ni.func;
> > +                   data = curr->u.ni.data;
> > +                   pthread_mutex_unlock(&se->lock);
> > +                   if (func)
> > +                           func(curr, data);
> > +                   pthread_mutex_unlock(&curr->lock);
> > +
> > +                   pthread_mutex_lock(&se->lock);
> > +                   curr->ctr--;
> > +                   if (!curr->ctr)
> > +                           destroy_req(curr);
> > +
> > +                   return 1;
> > +           }
> > +   }
> > +   for (curr = se->interrupts.next; curr != &se->interrupts;
> > +        curr = curr->next) {
> > +           if (curr->u.i.unique == req->u.i.unique)
> > +                   return 1;
> > +   }
> > +   return 0;
> > +}
> > +
> > +static void do_interrupt(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   struct fuse_interrupt_in *arg = (struct fuse_interrupt_in *) inarg;
> > +   struct fuse_session *se = req->se;
> > +
> > +   (void) nodeid;
> > +   if (se->debug)
> > +           fuse_log(FUSE_LOG_DEBUG, "INTERRUPT: %llu\n",
> > +                   (unsigned long long) arg->unique);
> > +
> > +   req->u.i.unique = arg->unique;
> > +
> > +   pthread_mutex_lock(&se->lock);
> > +   if (find_interrupted(se, req))
> > +           destroy_req(req);
> > +   else
> > +           list_add_req(req, &se->interrupts);
> > +   pthread_mutex_unlock(&se->lock);
> > +}
> > +
> > +static struct fuse_req *check_interrupt(struct fuse_session *se,
> > +                                   struct fuse_req *req)
> > +{
> > +   struct fuse_req *curr;
> > +
> > +   for (curr = se->interrupts.next; curr != &se->interrupts;
> > +        curr = curr->next) {
> > +           if (curr->u.i.unique == req->unique) {
> > +                   req->interrupted = 1;
> > +                   list_del_req(curr);
> > +                   free(curr);
> > +                   return NULL;
> > +           }
> > +   }
> > +   curr = se->interrupts.next;
> > +   if (curr != &se->interrupts) {
> > +           list_del_req(curr);
> > +           list_init_req(curr);
> > +           return curr;
> > +   } else
> > +           return NULL;
> > +}
> > +
> > +static void do_bmap(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   struct fuse_bmap_in *arg = (struct fuse_bmap_in *) inarg;
> > +
> > +   if (req->se->op.bmap)
> > +           req->se->op.bmap(req, nodeid, arg->blocksize, arg->block);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_ioctl(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   struct fuse_ioctl_in *arg = (struct fuse_ioctl_in *) inarg;
> > +   unsigned int flags = arg->flags;
> > +   void *in_buf = arg->in_size ? PARAM(arg) : NULL;
> > +   struct fuse_file_info fi;
> > +
> > +   if (flags & FUSE_IOCTL_DIR &&
> > +       !(req->se->conn.want & FUSE_CAP_IOCTL_DIR)) {
> > +           fuse_reply_err(req, ENOTTY);
> > +           return;
> > +   }
> > +
> > +   memset(&fi, 0, sizeof(fi));
> > +   fi.fh = arg->fh;
> > +
> > +   if (sizeof(void *) == 4 && req->se->conn.proto_minor >= 16 &&
> > +       !(flags & FUSE_IOCTL_32BIT)) {
> > +           req->ioctl_64bit = 1;
> > +   }
> > +
> > +   if (req->se->op.ioctl)
> > +           req->se->op.ioctl(req, nodeid, arg->cmd,
> > +                            (void *)(uintptr_t)arg->arg, &fi, flags,
> > +                            in_buf, arg->in_size, arg->out_size);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +void fuse_pollhandle_destroy(struct fuse_pollhandle *ph)
> > +{
> > +   free(ph);
> > +}
> > +
> > +static void do_poll(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   struct fuse_poll_in *arg = (struct fuse_poll_in *) inarg;
> > +   struct fuse_file_info fi;
> > +
> > +   memset(&fi, 0, sizeof(fi));
> > +   fi.fh = arg->fh;
> > +   fi.poll_events = arg->events;
> > +
> > +   if (req->se->op.poll) {
> > +           struct fuse_pollhandle *ph = NULL;
> > +
> > +           if (arg->flags & FUSE_POLL_SCHEDULE_NOTIFY) {
> > +                   ph = malloc(sizeof(struct fuse_pollhandle));
> > +                   if (ph == NULL) {
> > +                           fuse_reply_err(req, ENOMEM);
> > +                           return;
> > +                   }
> > +                   ph->kh = arg->kh;
> > +                   ph->se = req->se;
> > +           }
> > +
> > +           req->se->op.poll(req, nodeid, &fi, ph);
> > +   } else {
> > +           fuse_reply_err(req, ENOSYS);
> > +   }
> > +}
> > +
> > +static void do_fallocate(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   struct fuse_fallocate_in *arg = (struct fuse_fallocate_in *) inarg;
> > +   struct fuse_file_info fi;
> > +
> > +   memset(&fi, 0, sizeof(fi));
> > +   fi.fh = arg->fh;
> > +
> > +   if (req->se->op.fallocate)
> > +           req->se->op.fallocate(req, nodeid, arg->mode, arg->offset, 
> > arg->length, &fi);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_copy_file_range(fuse_req_t req, fuse_ino_t nodeid_in, const 
> > void *inarg)
> > +{
> > +   struct fuse_copy_file_range_in *arg = (struct fuse_copy_file_range_in 
> > *) inarg;
> > +   struct fuse_file_info fi_in, fi_out;
> > +
> > +   memset(&fi_in, 0, sizeof(fi_in));
> > +   fi_in.fh = arg->fh_in;
> > +
> > +   memset(&fi_out, 0, sizeof(fi_out));
> > +   fi_out.fh = arg->fh_out;
> > +
> > +
> > +   if (req->se->op.copy_file_range)
> > +           req->se->op.copy_file_range(req, nodeid_in, arg->off_in,
> > +                                       &fi_in, arg->nodeid_out,
> > +                                       arg->off_out, &fi_out, arg->len,
> > +                                       arg->flags);
> > +   else
> > +           fuse_reply_err(req, ENOSYS);
> > +}
> > +
> > +static void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
> > +{
> > +   struct fuse_init_in *arg = (struct fuse_init_in *) inarg;
> > +   struct fuse_init_out outarg;
> > +   struct fuse_session *se = req->se;
> > +   size_t bufsize = se->bufsize;
> > +   size_t outargsize = sizeof(outarg);
> > +
> > +   (void) nodeid;
> > +   if (se->debug) {
> > +           fuse_log(FUSE_LOG_DEBUG, "INIT: %u.%u\n", arg->major, 
> > arg->minor);
> > +           if (arg->major == 7 && arg->minor >= 6) {
> > +                   fuse_log(FUSE_LOG_DEBUG, "flags=0x%08x\n", arg->flags);
> > +                   fuse_log(FUSE_LOG_DEBUG, "max_readahead=0x%08x\n",
> > +                           arg->max_readahead);
> > +           }
> > +   }
> > +   se->conn.proto_major = arg->major;
> > +   se->conn.proto_minor = arg->minor;
> > +   se->conn.capable = 0;
> > +   se->conn.want = 0;
> > +
> > +   memset(&outarg, 0, sizeof(outarg));
> > +   outarg.major = FUSE_KERNEL_VERSION;
> > +   outarg.minor = FUSE_KERNEL_MINOR_VERSION;
> > +
> > +   if (arg->major < 7) {
> > +           fuse_log(FUSE_LOG_ERR, "fuse: unsupported protocol version: 
> > %u.%u\n",
> > +                   arg->major, arg->minor);
> > +           fuse_reply_err(req, EPROTO);
> > +           return;
> > +   }
> > +
> > +   if (arg->major > 7) {
> > +           /* Wait for a second INIT request with a 7.X version */
> > +           send_reply_ok(req, &outarg, sizeof(outarg));
> > +           return;
> > +   }
> > +
> > +   if (arg->minor >= 6) {
> > +           if (arg->max_readahead < se->conn.max_readahead)
> > +                   se->conn.max_readahead = arg->max_readahead;
> > +           if (arg->flags & FUSE_ASYNC_READ)
> > +                   se->conn.capable |= FUSE_CAP_ASYNC_READ;
> > +           if (arg->flags & FUSE_POSIX_LOCKS)
> > +                   se->conn.capable |= FUSE_CAP_POSIX_LOCKS;
> > +           if (arg->flags & FUSE_ATOMIC_O_TRUNC)
> > +                   se->conn.capable |= FUSE_CAP_ATOMIC_O_TRUNC;
> > +           if (arg->flags & FUSE_EXPORT_SUPPORT)
> > +                   se->conn.capable |= FUSE_CAP_EXPORT_SUPPORT;
> > +           if (arg->flags & FUSE_DONT_MASK)
> > +                   se->conn.capable |= FUSE_CAP_DONT_MASK;
> > +           if (arg->flags & FUSE_FLOCK_LOCKS)
> > +                   se->conn.capable |= FUSE_CAP_FLOCK_LOCKS;
> > +           if (arg->flags & FUSE_AUTO_INVAL_DATA)
> > +                   se->conn.capable |= FUSE_CAP_AUTO_INVAL_DATA;
> > +           if (arg->flags & FUSE_DO_READDIRPLUS)
> > +                   se->conn.capable |= FUSE_CAP_READDIRPLUS;
> > +           if (arg->flags & FUSE_READDIRPLUS_AUTO)
> > +                   se->conn.capable |= FUSE_CAP_READDIRPLUS_AUTO;
> > +           if (arg->flags & FUSE_ASYNC_DIO)
> > +                   se->conn.capable |= FUSE_CAP_ASYNC_DIO;
> > +           if (arg->flags & FUSE_WRITEBACK_CACHE)
> > +                   se->conn.capable |= FUSE_CAP_WRITEBACK_CACHE;
> > +           if (arg->flags & FUSE_NO_OPEN_SUPPORT)
> > +                   se->conn.capable |= FUSE_CAP_NO_OPEN_SUPPORT;
> > +           if (arg->flags & FUSE_PARALLEL_DIROPS)
> > +                   se->conn.capable |= FUSE_CAP_PARALLEL_DIROPS;
> > +           if (arg->flags & FUSE_POSIX_ACL)
> > +                   se->conn.capable |= FUSE_CAP_POSIX_ACL;
> > +           if (arg->flags & FUSE_HANDLE_KILLPRIV)
> > +                   se->conn.capable |= FUSE_CAP_HANDLE_KILLPRIV;
> > +           if (arg->flags & FUSE_NO_OPENDIR_SUPPORT)
> > +                   se->conn.capable |= FUSE_CAP_NO_OPENDIR_SUPPORT;
> > +           if (!(arg->flags & FUSE_MAX_PAGES)) {
> > +                   size_t max_bufsize =
> > +                           FUSE_DEFAULT_MAX_PAGES_PER_REQ * getpagesize()
> > +                           + FUSE_BUFFER_HEADER_SIZE;
> > +                   if (bufsize > max_bufsize) {
> > +                           bufsize = max_bufsize;
> > +                   }
> > +           }
> > +   } else {
> > +           se->conn.max_readahead = 0;
> > +   }
> > +
> > +   if (se->conn.proto_minor >= 14) {
> > +#ifdef HAVE_SPLICE
> > +#ifdef HAVE_VMSPLICE
> > +           se->conn.capable |= FUSE_CAP_SPLICE_WRITE | 
> > FUSE_CAP_SPLICE_MOVE;
> > +#endif
> > +           se->conn.capable |= FUSE_CAP_SPLICE_READ;
> > +#endif
> > +   }
> > +   if (se->conn.proto_minor >= 18)
> > +           se->conn.capable |= FUSE_CAP_IOCTL_DIR;
> > +
> > +   /* Default settings for modern filesystems.
> > +    *
> > +    * Most of these capabilities were disabled by default in
> > +    * libfuse2 for backwards compatibility reasons. In libfuse3,
> > +    * we can finally enable them by default (as long as they're
> > +    * supported by the kernel).
> > +    */
> > +#define LL_SET_DEFAULT(cond, cap) \
> > +   if ((cond) && (se->conn.capable & (cap))) \
> > +           se->conn.want |= (cap)
> > +   LL_SET_DEFAULT(1, FUSE_CAP_ASYNC_READ);
> > +   LL_SET_DEFAULT(1, FUSE_CAP_PARALLEL_DIROPS);
> > +   LL_SET_DEFAULT(1, FUSE_CAP_AUTO_INVAL_DATA);
> > +   LL_SET_DEFAULT(1, FUSE_CAP_HANDLE_KILLPRIV);
> > +   LL_SET_DEFAULT(1, FUSE_CAP_ASYNC_DIO);
> > +   LL_SET_DEFAULT(1, FUSE_CAP_IOCTL_DIR);
> > +   LL_SET_DEFAULT(1, FUSE_CAP_ATOMIC_O_TRUNC);
> > +   LL_SET_DEFAULT(se->op.write_buf, FUSE_CAP_SPLICE_READ);
> > +   LL_SET_DEFAULT(se->op.getlk && se->op.setlk,
> > +                  FUSE_CAP_POSIX_LOCKS);
> > +   LL_SET_DEFAULT(se->op.flock, FUSE_CAP_FLOCK_LOCKS);
> > +   LL_SET_DEFAULT(se->op.readdirplus, FUSE_CAP_READDIRPLUS);
> > +   LL_SET_DEFAULT(se->op.readdirplus && se->op.readdir,
> > +                  FUSE_CAP_READDIRPLUS_AUTO);
> > +   se->conn.time_gran = 1;
> > +   
> > +   if (bufsize < FUSE_MIN_READ_BUFFER) {
> > +           fuse_log(FUSE_LOG_ERR, "fuse: warning: buffer size too small: 
> > %zu\n",
> > +                   bufsize);
> > +           bufsize = FUSE_MIN_READ_BUFFER;
> > +   }
> > +   se->bufsize = bufsize;
> > +
> > +   if (se->conn.max_write > bufsize - FUSE_BUFFER_HEADER_SIZE)
> > +           se->conn.max_write = bufsize - FUSE_BUFFER_HEADER_SIZE;
> > +
> > +   se->got_init = 1;
> > +   if (se->op.init)
> > +           se->op.init(se->userdata, &se->conn);
> > +
> > +   if (se->conn.want & (~se->conn.capable)) {
> > +           fuse_log(FUSE_LOG_ERR, "fuse: error: filesystem requested 
> > capabilities "
> > +                   "0x%x that are not supported by kernel, aborting.\n",
> > +                   se->conn.want & (~se->conn.capable));
> > +           fuse_reply_err(req, EPROTO);
> > +           se->error = -EPROTO;
> > +           fuse_session_exit(se);
> > +           return;
> > +   }
> > +
> > +   unsigned max_read_mo = get_max_read(se->mo);
> > +   if (se->conn.max_read != max_read_mo) {
> > +           fuse_log(FUSE_LOG_ERR, "fuse: error: init() and 
> > fuse_session_new() "
> > +                   "requested different maximum read size (%u vs %u)\n",
> > +                   se->conn.max_read, max_read_mo);
> > +           fuse_reply_err(req, EPROTO);
> > +           se->error = -EPROTO;
> > +           fuse_session_exit(se);
> > +           return;
> > +   }
> > +
> > +   if (se->conn.max_write < bufsize - FUSE_BUFFER_HEADER_SIZE) {
> > +           se->bufsize = se->conn.max_write + FUSE_BUFFER_HEADER_SIZE;
> > +   }
> > +   if (arg->flags & FUSE_MAX_PAGES) {
> > +           outarg.flags |= FUSE_MAX_PAGES;
> > +           outarg.max_pages = (se->conn.max_write - 1) / getpagesize() + 1;
> > +   }
> > +
> > +   /* Always enable big writes, this is superseded
> > +      by the max_write option */
> > +   outarg.flags |= FUSE_BIG_WRITES;
> > +
> > +   if (se->conn.want & FUSE_CAP_ASYNC_READ)
> > +           outarg.flags |= FUSE_ASYNC_READ;
> > +   if (se->conn.want & FUSE_CAP_POSIX_LOCKS)
> > +           outarg.flags |= FUSE_POSIX_LOCKS;
> > +   if (se->conn.want & FUSE_CAP_ATOMIC_O_TRUNC)
> > +           outarg.flags |= FUSE_ATOMIC_O_TRUNC;
> > +   if (se->conn.want & FUSE_CAP_EXPORT_SUPPORT)
> > +           outarg.flags |= FUSE_EXPORT_SUPPORT;
> > +   if (se->conn.want & FUSE_CAP_DONT_MASK)
> > +           outarg.flags |= FUSE_DONT_MASK;
> > +   if (se->conn.want & FUSE_CAP_FLOCK_LOCKS)
> > +           outarg.flags |= FUSE_FLOCK_LOCKS;
> > +   if (se->conn.want & FUSE_CAP_AUTO_INVAL_DATA)
> > +           outarg.flags |= FUSE_AUTO_INVAL_DATA;
> > +   if (se->conn.want & FUSE_CAP_READDIRPLUS)
> > +           outarg.flags |= FUSE_DO_READDIRPLUS;
> > +   if (se->conn.want & FUSE_CAP_READDIRPLUS_AUTO)
> > +           outarg.flags |= FUSE_READDIRPLUS_AUTO;
> > +   if (se->conn.want & FUSE_CAP_ASYNC_DIO)
> > +           outarg.flags |= FUSE_ASYNC_DIO;
> > +   if (se->conn.want & FUSE_CAP_WRITEBACK_CACHE)
> > +           outarg.flags |= FUSE_WRITEBACK_CACHE;
> > +   if (se->conn.want & FUSE_CAP_POSIX_ACL)
> > +           outarg.flags |= FUSE_POSIX_ACL;
> > +   outarg.max_readahead = se->conn.max_readahead;
> > +   outarg.max_write = se->conn.max_write;
> > +   if (se->conn.proto_minor >= 13) {
> > +           if (se->conn.max_background >= (1 << 16))
> > +                   se->conn.max_background = (1 << 16) - 1;
> > +           if (se->conn.congestion_threshold > se->conn.max_background)
> > +                   se->conn.congestion_threshold = se->conn.max_background;
> > +           if (!se->conn.congestion_threshold) {
> > +                   se->conn.congestion_threshold =
> > +                           se->conn.max_background * 3 / 4;
> > +           }
> > +
> > +           outarg.max_background = se->conn.max_background;
> > +           outarg.congestion_threshold = se->conn.congestion_threshold;
> > +   }
> > +   if (se->conn.proto_minor >= 23)
> > +           outarg.time_gran = se->conn.time_gran;
> > +
> > +   if (se->debug) {
> > +           fuse_log(FUSE_LOG_DEBUG, "   INIT: %u.%u\n", outarg.major, 
> > outarg.minor);
> > +           fuse_log(FUSE_LOG_DEBUG, "   flags=0x%08x\n", outarg.flags);
> > +           fuse_log(FUSE_LOG_DEBUG, "   max_readahead=0x%08x\n",
> > +                   outarg.max_readahead);
> > +           fuse_log(FUSE_LOG_DEBUG, "   max_write=0x%08x\n", 
> > outarg.max_write);
> > +           fuse_log(FUSE_LOG_DEBUG, "   max_background=%i\n",
> > +                   outarg.max_background);
> > +           fuse_log(FUSE_LOG_DEBUG, "   congestion_threshold=%i\n",
> > +                   outarg.congestion_threshold);
> > +           fuse_log(FUSE_LOG_DEBUG, "   time_gran=%u\n",
> > +                   outarg.time_gran);
> > +   }
> > +   if (arg->minor < 5)
> > +           outargsize = FUSE_COMPAT_INIT_OUT_SIZE;
> > +   else if (arg->minor < 23)
> > +           outargsize = FUSE_COMPAT_22_INIT_OUT_SIZE;
> > +
> > +   send_reply_ok(req, &outarg, outargsize);
> > +}
> > +
> > +static void do_destroy(fuse_req_t req, fuse_ino_t nodeid, const void 
> > *inarg)
> > +{
> > +   struct fuse_session *se = req->se;
> > +
> > +   (void) nodeid;
> > +   (void) inarg;
> > +
> > +   se->got_destroy = 1;
> > +   if (se->op.destroy)
> > +           se->op.destroy(se->userdata);
> > +
> > +   send_reply_ok(req, NULL, 0);
> > +}
> > +
> > +static void list_del_nreq(struct fuse_notify_req *nreq)
> > +{
> > +   struct fuse_notify_req *prev = nreq->prev;
> > +   struct fuse_notify_req *next = nreq->next;
> > +   prev->next = next;
> > +   next->prev = prev;
> > +}
> > +
> > +static void list_add_nreq(struct fuse_notify_req *nreq,
> > +                     struct fuse_notify_req *next)
> > +{
> > +   struct fuse_notify_req *prev = next->prev;
> > +   nreq->next = next;
> > +   nreq->prev = prev;
> > +   prev->next = nreq;
> > +   next->prev = nreq;
> > +}
> > +
> > +static void list_init_nreq(struct fuse_notify_req *nreq)
> > +{
> > +   nreq->next = nreq;
> > +   nreq->prev = nreq;
> > +}
> > +
> > +static void do_notify_reply(fuse_req_t req, fuse_ino_t nodeid,
> > +                       const void *inarg, const struct fuse_buf *buf)
> > +{
> > +   struct fuse_session *se = req->se;
> > +   struct fuse_notify_req *nreq;
> > +   struct fuse_notify_req *head;
> > +
> > +   pthread_mutex_lock(&se->lock);
> > +   head = &se->notify_list;
> > +   for (nreq = head->next; nreq != head; nreq = nreq->next) {
> > +           if (nreq->unique == req->unique) {
> > +                   list_del_nreq(nreq);
> > +                   break;
> > +           }
> > +   }
> > +   pthread_mutex_unlock(&se->lock);
> > +
> > +   if (nreq != head)
> > +           nreq->reply(nreq, req, nodeid, inarg, buf);
> > +}
> > +
> > +static int send_notify_iov(struct fuse_session *se, int notify_code,
> > +                      struct iovec *iov, int count)
> > +{
> > +   struct fuse_out_header out;
> > +
> > +   if (!se->got_init)
> > +           return -ENOTCONN;
> > +
> > +   out.unique = 0;
> > +   out.error = notify_code;
> > +   iov[0].iov_base = &out;
> > +   iov[0].iov_len = sizeof(struct fuse_out_header);
> > +
> > +   return fuse_send_msg(se, NULL, iov, count);
> > +}
> > +
> > +int fuse_lowlevel_notify_poll(struct fuse_pollhandle *ph)
> > +{
> > +   if (ph != NULL) {
> > +           struct fuse_notify_poll_wakeup_out outarg;
> > +           struct iovec iov[2];
> > +
> > +           outarg.kh = ph->kh;
> > +
> > +           iov[1].iov_base = &outarg;
> > +           iov[1].iov_len = sizeof(outarg);
> > +
> > +           return send_notify_iov(ph->se, FUSE_NOTIFY_POLL, iov, 2);
> > +   } else {
> > +           return 0;
> > +   }
> > +}
> > +
> > +int fuse_lowlevel_notify_inval_inode(struct fuse_session *se, fuse_ino_t 
> > ino,
> > +                                off_t off, off_t len)
> > +{
> > +   struct fuse_notify_inval_inode_out outarg;
> > +   struct iovec iov[2];
> > +
> > +   if (!se)
> > +           return -EINVAL;
> > +
> > +   if (se->conn.proto_major < 6 || se->conn.proto_minor < 12)
> > +           return -ENOSYS;
> > +   
> > +   outarg.ino = ino;
> > +   outarg.off = off;
> > +   outarg.len = len;
> > +
> > +   iov[1].iov_base = &outarg;
> > +   iov[1].iov_len = sizeof(outarg);
> > +
> > +   return send_notify_iov(se, FUSE_NOTIFY_INVAL_INODE, iov, 2);
> > +}
> > +
> > +int fuse_lowlevel_notify_inval_entry(struct fuse_session *se, fuse_ino_t 
> > parent,
> > +                                const char *name, size_t namelen)
> > +{
> > +   struct fuse_notify_inval_entry_out outarg;
> > +   struct iovec iov[3];
> > +
> > +   if (!se)
> > +           return -EINVAL;
> > +   
> > +   if (se->conn.proto_major < 6 || se->conn.proto_minor < 12)
> > +           return -ENOSYS;
> > +
> > +   outarg.parent = parent;
> > +   outarg.namelen = namelen;
> > +   outarg.padding = 0;
> > +
> > +   iov[1].iov_base = &outarg;
> > +   iov[1].iov_len = sizeof(outarg);
> > +   iov[2].iov_base = (void *)name;
> > +   iov[2].iov_len = namelen + 1;
> > +
> > +   return send_notify_iov(se, FUSE_NOTIFY_INVAL_ENTRY, iov, 3);
> > +}
> > +
> > +int fuse_lowlevel_notify_delete(struct fuse_session *se,
> > +                           fuse_ino_t parent, fuse_ino_t child,
> > +                           const char *name, size_t namelen)
> > +{
> > +   struct fuse_notify_delete_out outarg;
> > +   struct iovec iov[3];
> > +
> > +   if (!se)
> > +           return -EINVAL;
> > +
> > +   if (se->conn.proto_major < 6 || se->conn.proto_minor < 18)
> > +           return -ENOSYS;
> > +
> > +   outarg.parent = parent;
> > +   outarg.child = child;
> > +   outarg.namelen = namelen;
> > +   outarg.padding = 0;
> > +
> > +   iov[1].iov_base = &outarg;
> > +   iov[1].iov_len = sizeof(outarg);
> > +   iov[2].iov_base = (void *)name;
> > +   iov[2].iov_len = namelen + 1;
> > +
> > +   return send_notify_iov(se, FUSE_NOTIFY_DELETE, iov, 3);
> > +}
> > +
> > +int fuse_lowlevel_notify_store(struct fuse_session *se, fuse_ino_t ino,
> > +                          off_t offset, struct fuse_bufvec *bufv,
> > +                          enum fuse_buf_copy_flags flags)
> > +{
> > +   struct fuse_out_header out;
> > +   struct fuse_notify_store_out outarg;
> > +   struct iovec iov[3];
> > +   size_t size = fuse_buf_size(bufv);
> > +   int res;
> > +
> > +   if (!se)
> > +           return -EINVAL;
> > +
> > +   if (se->conn.proto_major < 6 || se->conn.proto_minor < 15)
> > +           return -ENOSYS;
> > +
> > +   out.unique = 0;
> > +   out.error = FUSE_NOTIFY_STORE;
> > +
> > +   outarg.nodeid = ino;
> > +   outarg.offset = offset;
> > +   outarg.size = size;
> > +   outarg.padding = 0;
> > +
> > +   iov[0].iov_base = &out;
> > +   iov[0].iov_len = sizeof(out);
> > +   iov[1].iov_base = &outarg;
> > +   iov[1].iov_len = sizeof(outarg);
> > +
> > +   res = fuse_send_data_iov(se, NULL, iov, 2, bufv, flags);
> > +   if (res > 0)
> > +           res = -res;
> > +
> > +   return res;
> > +}
> > +
> > +struct fuse_retrieve_req {
> > +   struct fuse_notify_req nreq;
> > +   void *cookie;
> > +};
> > +
> > +static void fuse_ll_retrieve_reply(struct fuse_notify_req *nreq,
> > +                              fuse_req_t req, fuse_ino_t ino,
> > +                              const void *inarg,
> > +                              const struct fuse_buf *ibuf)
> > +{
> > +   struct fuse_session *se = req->se;
> > +   struct fuse_retrieve_req *rreq =
> > +           container_of(nreq, struct fuse_retrieve_req, nreq);
> > +   const struct fuse_notify_retrieve_in *arg = inarg;
> > +   struct fuse_bufvec bufv = {
> > +           .buf[0] = *ibuf,
> > +           .count = 1,
> > +   };
> > +
> > +   if (!(bufv.buf[0].flags & FUSE_BUF_IS_FD))
> > +           bufv.buf[0].mem = PARAM(arg);
> > +
> > +   bufv.buf[0].size -= sizeof(struct fuse_in_header) +
> > +           sizeof(struct fuse_notify_retrieve_in);
> > +
> > +   if (bufv.buf[0].size < arg->size) {
> > +           fuse_log(FUSE_LOG_ERR, "fuse: retrieve reply: buffer size too 
> > small\n");
> > +           fuse_reply_none(req);
> > +           goto out;
> > +   }
> > +   bufv.buf[0].size = arg->size;
> > +
> > +   if (se->op.retrieve_reply) {
> > +           se->op.retrieve_reply(req, rreq->cookie, ino,
> > +                                     arg->offset, &bufv);
> > +   } else {
> > +           fuse_reply_none(req);
> > +   }
> > +out:
> > +   free(rreq);
> > +   if ((ibuf->flags & FUSE_BUF_IS_FD) && bufv.idx < bufv.count)
> > +           fuse_ll_clear_pipe(se);
> > +}
> > +
> > +int fuse_lowlevel_notify_retrieve(struct fuse_session *se, fuse_ino_t ino,
> > +                             size_t size, off_t offset, void *cookie)
> > +{
> > +   struct fuse_notify_retrieve_out outarg;
> > +   struct iovec iov[2];
> > +   struct fuse_retrieve_req *rreq;
> > +   int err;
> > +
> > +   if (!se)
> > +           return -EINVAL;
> > +
> > +   if (se->conn.proto_major < 6 || se->conn.proto_minor < 15)
> > +           return -ENOSYS;
> > +
> > +   rreq = malloc(sizeof(*rreq));
> > +   if (rreq == NULL)
> > +           return -ENOMEM;
> > +
> > +   pthread_mutex_lock(&se->lock);
> > +   rreq->cookie = cookie;
> > +   rreq->nreq.unique = se->notify_ctr++;
> > +   rreq->nreq.reply = fuse_ll_retrieve_reply;
> > +   list_add_nreq(&rreq->nreq, &se->notify_list);
> > +   pthread_mutex_unlock(&se->lock);
> > +
> > +   outarg.notify_unique = rreq->nreq.unique;
> > +   outarg.nodeid = ino;
> > +   outarg.offset = offset;
> > +   outarg.size = size;
> > +   outarg.padding = 0;
> > +
> > +   iov[1].iov_base = &outarg;
> > +   iov[1].iov_len = sizeof(outarg);
> > +
> > +   err = send_notify_iov(se, FUSE_NOTIFY_RETRIEVE, iov, 2);
> > +   if (err) {
> > +           pthread_mutex_lock(&se->lock);
> > +           list_del_nreq(&rreq->nreq);
> > +           pthread_mutex_unlock(&se->lock);
> > +           free(rreq);
> > +   }
> > +
> > +   return err;
> > +}
> > +
> > +void *fuse_req_userdata(fuse_req_t req)
> > +{
> > +   return req->se->userdata;
> > +}
> > +
> > +const struct fuse_ctx *fuse_req_ctx(fuse_req_t req)
> > +{
> > +   return &req->ctx;
> > +}
> > +
> > +void fuse_req_interrupt_func(fuse_req_t req, fuse_interrupt_func_t func,
> > +                        void *data)
> > +{
> > +   pthread_mutex_lock(&req->lock);
> > +   pthread_mutex_lock(&req->se->lock);
> > +   req->u.ni.func = func;
> > +   req->u.ni.data = data;
> > +   pthread_mutex_unlock(&req->se->lock);
> > +   if (req->interrupted && func)
> > +           func(req, data);
> > +   pthread_mutex_unlock(&req->lock);
> > +}
> > +
> > +int fuse_req_interrupted(fuse_req_t req)
> > +{
> > +   int interrupted;
> > +
> > +   pthread_mutex_lock(&req->se->lock);
> > +   interrupted = req->interrupted;
> > +   pthread_mutex_unlock(&req->se->lock);
> > +
> > +   return interrupted;
> > +}
> > +
> > +static struct {
> > +   void (*func)(fuse_req_t, fuse_ino_t, const void *);
> > +   const char *name;
> > +} fuse_ll_ops[] = {
> > +   [FUSE_LOOKUP]      = { do_lookup,      "LOOKUP"      },
> > +   [FUSE_FORGET]      = { do_forget,      "FORGET"      },
> > +   [FUSE_GETATTR]     = { do_getattr,     "GETATTR"     },
> > +   [FUSE_SETATTR]     = { do_setattr,     "SETATTR"     },
> > +   [FUSE_READLINK]    = { do_readlink,    "READLINK"    },
> > +   [FUSE_SYMLINK]     = { do_symlink,     "SYMLINK"     },
> > +   [FUSE_MKNOD]       = { do_mknod,       "MKNOD"       },
> > +   [FUSE_MKDIR]       = { do_mkdir,       "MKDIR"       },
> > +   [FUSE_UNLINK]      = { do_unlink,      "UNLINK"      },
> > +   [FUSE_RMDIR]       = { do_rmdir,       "RMDIR"       },
> > +   [FUSE_RENAME]      = { do_rename,      "RENAME"      },
> > +   [FUSE_LINK]        = { do_link,        "LINK"        },
> > +   [FUSE_OPEN]        = { do_open,        "OPEN"        },
> > +   [FUSE_READ]        = { do_read,        "READ"        },
> > +   [FUSE_WRITE]       = { do_write,       "WRITE"       },
> > +   [FUSE_STATFS]      = { do_statfs,      "STATFS"      },
> > +   [FUSE_RELEASE]     = { do_release,     "RELEASE"     },
> > +   [FUSE_FSYNC]       = { do_fsync,       "FSYNC"       },
> > +   [FUSE_SETXATTR]    = { do_setxattr,    "SETXATTR"    },
> > +   [FUSE_GETXATTR]    = { do_getxattr,    "GETXATTR"    },
> > +   [FUSE_LISTXATTR]   = { do_listxattr,   "LISTXATTR"   },
> > +   [FUSE_REMOVEXATTR] = { do_removexattr, "REMOVEXATTR" },
> > +   [FUSE_FLUSH]       = { do_flush,       "FLUSH"       },
> > +   [FUSE_INIT]        = { do_init,        "INIT"        },
> > +   [FUSE_OPENDIR]     = { do_opendir,     "OPENDIR"     },
> > +   [FUSE_READDIR]     = { do_readdir,     "READDIR"     },
> > +   [FUSE_RELEASEDIR]  = { do_releasedir,  "RELEASEDIR"  },
> > +   [FUSE_FSYNCDIR]    = { do_fsyncdir,    "FSYNCDIR"    },
> > +   [FUSE_GETLK]       = { do_getlk,       "GETLK"       },
> > +   [FUSE_SETLK]       = { do_setlk,       "SETLK"       },
> > +   [FUSE_SETLKW]      = { do_setlkw,      "SETLKW"      },
> > +   [FUSE_ACCESS]      = { do_access,      "ACCESS"      },
> > +   [FUSE_CREATE]      = { do_create,      "CREATE"      },
> > +   [FUSE_INTERRUPT]   = { do_interrupt,   "INTERRUPT"   },
> > +   [FUSE_BMAP]        = { do_bmap,        "BMAP"        },
> > +   [FUSE_IOCTL]       = { do_ioctl,       "IOCTL"       },
> > +   [FUSE_POLL]        = { do_poll,        "POLL"        },
> > +   [FUSE_FALLOCATE]   = { do_fallocate,   "FALLOCATE"   },
> > +   [FUSE_DESTROY]     = { do_destroy,     "DESTROY"     },
> > +   [FUSE_NOTIFY_REPLY] = { (void *) 1,    "NOTIFY_REPLY" },
> > +   [FUSE_BATCH_FORGET] = { do_batch_forget, "BATCH_FORGET" },
> > +   [FUSE_READDIRPLUS] = { do_readdirplus,  "READDIRPLUS"},
> > +   [FUSE_RENAME2]     = { do_rename2,      "RENAME2"    },
> > +   [FUSE_COPY_FILE_RANGE] = { do_copy_file_range, "COPY_FILE_RANGE" },
> > +   [CUSE_INIT]        = { cuse_lowlevel_init, "CUSE_INIT"   },
> > +};
> > +
> > +#define FUSE_MAXOP (sizeof(fuse_ll_ops) / sizeof(fuse_ll_ops[0]))
> > +
> > +static const char *opname(enum fuse_opcode opcode)
> > +{
> > +   if (opcode >= FUSE_MAXOP || !fuse_ll_ops[opcode].name)
> > +           return "???";
> > +   else
> > +           return fuse_ll_ops[opcode].name;
> > +}
> > +
> > +static int fuse_ll_copy_from_pipe(struct fuse_bufvec *dst,
> > +                             struct fuse_bufvec *src)
> > +{
> > +   ssize_t res = fuse_buf_copy(dst, src, 0);
> > +   if (res < 0) {
> > +           fuse_log(FUSE_LOG_ERR, "fuse: copy from pipe: %s\n", 
> > strerror(-res));
> > +           return res;
> > +   }
> > +   if ((size_t)res < fuse_buf_size(dst)) {
> > +           fuse_log(FUSE_LOG_ERR, "fuse: copy from pipe: short read\n");
> > +           return -1;
> > +   }
> > +   return 0;
> > +}
> > +
> > +void fuse_session_process_buf(struct fuse_session *se,
> > +                         const struct fuse_buf *buf)
> > +{
> > +   fuse_session_process_buf_int(se, buf, NULL);
> > +}
> > +
> > +void fuse_session_process_buf_int(struct fuse_session *se,
> > +                             const struct fuse_buf *buf, struct fuse_chan 
> > *ch)
> > +{
> > +   const size_t write_header_size = sizeof(struct fuse_in_header) +
> > +           sizeof(struct fuse_write_in);
> > +   struct fuse_bufvec bufv = { .buf[0] = *buf, .count = 1 };
> > +   struct fuse_bufvec tmpbuf = FUSE_BUFVEC_INIT(write_header_size);
> > +   struct fuse_in_header *in;
> > +   const void *inarg;
> > +   struct fuse_req *req;
> > +   void *mbuf = NULL;
> > +   int err;
> > +   int res;
> > +
> > +   if (buf->flags & FUSE_BUF_IS_FD) {
> > +           if (buf->size < tmpbuf.buf[0].size)
> > +                   tmpbuf.buf[0].size = buf->size;
> > +
> > +           mbuf = malloc(tmpbuf.buf[0].size);
> > +           if (mbuf == NULL) {
> > +                   fuse_log(FUSE_LOG_ERR, "fuse: failed to allocate 
> > header\n");
> > +                   goto clear_pipe;
> > +           }
> > +           tmpbuf.buf[0].mem = mbuf;
> > +
> > +           res = fuse_ll_copy_from_pipe(&tmpbuf, &bufv);
> > +           if (res < 0)
> > +                   goto clear_pipe;
> > +
> > +           in = mbuf;
> > +   } else {
> > +           in = buf->mem;
> > +   }
> > +
> > +   if (se->debug) {
> > +           fuse_log(FUSE_LOG_DEBUG,
> > +                   "unique: %llu, opcode: %s (%i), nodeid: %llu, insize: 
> > %zu, pid: %u\n",
> > +                   (unsigned long long) in->unique,
> > +                   opname((enum fuse_opcode) in->opcode), in->opcode,
> > +                   (unsigned long long) in->nodeid, buf->size, in->pid);
> > +   }
> > +
> > +   req = fuse_ll_alloc_req(se);
> > +   if (req == NULL) {
> > +           struct fuse_out_header out = {
> > +                   .unique = in->unique,
> > +                   .error = -ENOMEM,
> > +           };
> > +           struct iovec iov = {
> > +                   .iov_base = &out,
> > +                   .iov_len = sizeof(struct fuse_out_header),
> > +           };
> > +
> > +           fuse_send_msg(se, ch, &iov, 1);
> > +           goto clear_pipe;
> > +   }
> > +
> > +   req->unique = in->unique;
> > +   req->ctx.uid = in->uid;
> > +   req->ctx.gid = in->gid;
> > +   req->ctx.pid = in->pid;
> > +   req->ch = ch ? fuse_chan_get(ch) : NULL;
> > +
> > +   err = EIO;
> > +   if (!se->got_init) {
> > +           enum fuse_opcode expected;
> > +
> > +           expected = se->cuse_data ? CUSE_INIT : FUSE_INIT;
> > +           if (in->opcode != expected)
> > +                   goto reply_err;
> > +   } else if (in->opcode == FUSE_INIT || in->opcode == CUSE_INIT)
> > +           goto reply_err;
> > +
> > +   err = EACCES;
> > +   /* Implement -o allow_root */
> > +   if (se->deny_others && in->uid != se->owner && in->uid != 0 &&
> > +            in->opcode != FUSE_INIT && in->opcode != FUSE_READ &&
> > +            in->opcode != FUSE_WRITE && in->opcode != FUSE_FSYNC &&
> > +            in->opcode != FUSE_RELEASE && in->opcode != FUSE_READDIR &&
> > +            in->opcode != FUSE_FSYNCDIR && in->opcode != FUSE_RELEASEDIR &&
> > +            in->opcode != FUSE_NOTIFY_REPLY &&
> > +            in->opcode != FUSE_READDIRPLUS)
> > +           goto reply_err;
> > +
> > +   err = ENOSYS;
> > +   if (in->opcode >= FUSE_MAXOP || !fuse_ll_ops[in->opcode].func)
> > +           goto reply_err;
> > +   if (in->opcode != FUSE_INTERRUPT) {
> > +           struct fuse_req *intr;
> > +           pthread_mutex_lock(&se->lock);
> > +           intr = check_interrupt(se, req);
> > +           list_add_req(req, &se->list);
> > +           pthread_mutex_unlock(&se->lock);
> > +           if (intr)
> > +                   fuse_reply_err(intr, EAGAIN);
> > +   }
> > +
> > +   if ((buf->flags & FUSE_BUF_IS_FD) && write_header_size < buf->size &&
> > +       (in->opcode != FUSE_WRITE || !se->op.write_buf) &&
> > +       in->opcode != FUSE_NOTIFY_REPLY) {
> > +           void *newmbuf;
> > +
> > +           err = ENOMEM;
> > +           newmbuf = realloc(mbuf, buf->size);
> > +           if (newmbuf == NULL)
> > +                   goto reply_err;
> > +           mbuf = newmbuf;
> > +
> > +           tmpbuf = FUSE_BUFVEC_INIT(buf->size - write_header_size);
> > +           tmpbuf.buf[0].mem = (char *)mbuf + write_header_size;
> > +
> > +           res = fuse_ll_copy_from_pipe(&tmpbuf, &bufv);
> > +           err = -res;
> > +           if (res < 0)
> > +                   goto reply_err;
> > +
> > +           in = mbuf;
> > +   }
> > +
> > +   inarg = (void *) &in[1];
> > +   if (in->opcode == FUSE_WRITE && se->op.write_buf)
> > +           do_write_buf(req, in->nodeid, inarg, buf);
> > +   else if (in->opcode == FUSE_NOTIFY_REPLY)
> > +           do_notify_reply(req, in->nodeid, inarg, buf);
> > +   else
> > +           fuse_ll_ops[in->opcode].func(req, in->nodeid, inarg);
> > +
> > +out_free:
> > +   free(mbuf);
> > +   return;
> > +
> > +reply_err:
> > +   fuse_reply_err(req, err);
> > +clear_pipe:
> > +   if (buf->flags & FUSE_BUF_IS_FD)
> > +           fuse_ll_clear_pipe(se);
> > +   goto out_free;
> > +}
> > +
> > +#define LL_OPTION(n,o,v) \
> > +   { n, offsetof(struct fuse_session, o), v }
> > +
> > +static const struct fuse_opt fuse_ll_opts[] = {
> > +   LL_OPTION("debug", debug, 1),
> > +   LL_OPTION("-d", debug, 1),
> > +   LL_OPTION("--debug", debug, 1),
> > +   LL_OPTION("allow_root", deny_others, 1),
> > +   FUSE_OPT_END
> > +};
> > +
> > +void fuse_lowlevel_version(void)
> > +{
> > +   printf("using FUSE kernel interface version %i.%i\n",
> > +          FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
> > +   fuse_mount_version();
> > +}
> > +
> > +void fuse_lowlevel_help(void)
> > +{
> > +   /* These are not all options, but the ones that are
> > +      potentially of interest to an end-user */
> > +   printf(
> > +"    -o allow_other         allow access by all users\n"
> > +"    -o allow_root          allow access by root\n"
> > +"    -o auto_unmount        auto unmount on process termination\n");
> > +}
> > +
> > +void fuse_session_destroy(struct fuse_session *se)
> > +{
> > +   struct fuse_ll_pipe *llp;
> > +
> > +   if (se->got_init && !se->got_destroy) {
> > +           if (se->op.destroy)
> > +                   se->op.destroy(se->userdata);
> > +   }
> > +   llp = pthread_getspecific(se->pipe_key);
> > +   if (llp != NULL)
> > +           fuse_ll_pipe_free(llp);
> > +   pthread_key_delete(se->pipe_key);
> > +   pthread_mutex_destroy(&se->lock);
> > +   free(se->cuse_data);
> > +   if (se->fd != -1)
> > +           close(se->fd);
> > +   destroy_mount_opts(se->mo);
> > +   free(se);
> > +}
> > +
> > +
> > +static void fuse_ll_pipe_destructor(void *data)
> > +{
> > +   struct fuse_ll_pipe *llp = data;
> > +   fuse_ll_pipe_free(llp);
> > +}
> > +
> > +int fuse_session_receive_buf(struct fuse_session *se, struct fuse_buf *buf)
> > +{
> > +   return fuse_session_receive_buf_int(se, buf, NULL);
> > +}
> > +
> > +int fuse_session_receive_buf_int(struct fuse_session *se, struct fuse_buf 
> > *buf,
> > +                            struct fuse_chan *ch)
> > +{
> > +   int err;
> > +   ssize_t res;
> > +#ifdef HAVE_SPLICE
> > +   size_t bufsize = se->bufsize;
> > +   struct fuse_ll_pipe *llp;
> > +   struct fuse_buf tmpbuf;
> > +
> > +   if (se->conn.proto_minor < 14 || !(se->conn.want & 
> > FUSE_CAP_SPLICE_READ))
> > +           goto fallback;
> > +
> > +   llp = fuse_ll_get_pipe(se);
> > +   if (llp == NULL)
> > +           goto fallback;
> > +
> > +   if (llp->size < bufsize) {
> > +           if (llp->can_grow) {
> > +                   res = fcntl(llp->pipe[0], F_SETPIPE_SZ, bufsize);
> > +                   if (res == -1) {
> > +                           llp->can_grow = 0;
> > +                           res = grow_pipe_to_max(llp->pipe[0]);
> > +                           if (res > 0)
> > +                                   llp->size = res;
> > +                           goto fallback;
> > +                   }
> > +                   llp->size = res;
> > +           }
> > +           if (llp->size < bufsize)
> > +                   goto fallback;
> > +   }
> > +
> > +   res = splice(ch ? ch->fd : se->fd,
> > +                NULL, llp->pipe[1], NULL, bufsize, 0);
> > +   err = errno;
> > +
> > +   if (fuse_session_exited(se))
> > +           return 0;
> > +
> > +   if (res == -1) {
> > +           if (err == ENODEV) {
> > +                   /* Filesystem was unmounted, or connection was aborted
> > +                      via /sys/fs/fuse/connections */
> > +                   fuse_session_exit(se);
> > +                   return 0;
> > +           }
> > +           if (err != EINTR && err != EAGAIN)
> > +                   perror("fuse: splice from device");
> > +           return -err;
> > +   }
> > +
> > +   if (res < sizeof(struct fuse_in_header)) {
> > +           fuse_log(FUSE_LOG_ERR, "short splice from fuse device\n");
> > +           return -EIO;
> > +   }
> > +
> > +   tmpbuf = (struct fuse_buf) {
> > +           .size = res,
> > +           .flags = FUSE_BUF_IS_FD,
> > +           .fd = llp->pipe[0],
> > +   };
> > +
> > +   /*
> > +    * Don't bother with zero copy for small requests.
> > +    * fuse_loop_mt() needs to check for FORGET so this more than
> > +    * just an optimization.
> > +    */
> > +   if (res < sizeof(struct fuse_in_header) +
> > +       sizeof(struct fuse_write_in) + pagesize) {
> > +           struct fuse_bufvec src = { .buf[0] = tmpbuf, .count = 1 };
> > +           struct fuse_bufvec dst = { .count = 1 };
> > +
> > +           if (!buf->mem) {
> > +                   buf->mem = malloc(se->bufsize);
> > +                   if (!buf->mem) {
> > +                           fuse_log(FUSE_LOG_ERR,
> > +                                   "fuse: failed to allocate read 
> > buffer\n");
> > +                           return -ENOMEM;
> > +                   }
> > +           }
> > +           buf->size = se->bufsize;
> > +           buf->flags = 0;
> > +           dst.buf[0] = *buf;
> > +
> > +           res = fuse_buf_copy(&dst, &src, 0);
> > +           if (res < 0) {
> > +                   fuse_log(FUSE_LOG_ERR, "fuse: copy from pipe: %s\n",
> > +                           strerror(-res));
> > +                   fuse_ll_clear_pipe(se);
> > +                   return res;
> > +           }
> > +           if (res < tmpbuf.size) {
> > +                   fuse_log(FUSE_LOG_ERR, "fuse: copy from pipe: short 
> > read\n");
> > +                   fuse_ll_clear_pipe(se);
> > +                   return -EIO;
> > +           }
> > +           assert(res == tmpbuf.size);
> > +
> > +   } else {
> > +           /* Don't overwrite buf->mem, as that would cause a leak */
> > +           buf->fd = tmpbuf.fd;
> > +           buf->flags = tmpbuf.flags;
> > +   }
> > +   buf->size = tmpbuf.size;
> > +
> > +   return res;
> > +
> > +fallback:
> > +#endif
> > +   if (!buf->mem) {
> > +           buf->mem = malloc(se->bufsize);
> > +           if (!buf->mem) {
> > +                   fuse_log(FUSE_LOG_ERR,
> > +                           "fuse: failed to allocate read buffer\n");
> > +                   return -ENOMEM;
> > +           }
> > +   }
> > +
> > +restart:
> > +   res = read(ch ? ch->fd : se->fd, buf->mem, se->bufsize);
> > +   err = errno;
> > +
> > +   if (fuse_session_exited(se))
> > +           return 0;
> > +   if (res == -1) {
> > +           /* ENOENT means the operation was interrupted, it's safe
> > +              to restart */
> > +           if (err == ENOENT)
> > +                   goto restart;
> > +
> > +           if (err == ENODEV) {
> > +                   /* Filesystem was unmounted, or connection was aborted
> > +                      via /sys/fs/fuse/connections */
> > +                   fuse_session_exit(se);
> > +                   return 0;
> > +           }
> > +           /* Errors occurring during normal operation: EINTR (read
> > +              interrupted), EAGAIN (nonblocking I/O), ENODEV (filesystem
> > +              umounted) */
> > +           if (err != EINTR && err != EAGAIN)
> > +                   perror("fuse: reading device");
> > +           return -err;
> > +   }
> > +   if ((size_t) res < sizeof(struct fuse_in_header)) {
> > +           fuse_log(FUSE_LOG_ERR, "short read on fuse device\n");
> > +           return -EIO;
> > +   }
> > +
> > +   buf->size = res;
> > +
> > +   return res;
> > +}
> > +
> > +struct fuse_session *fuse_session_new(struct fuse_args *args,
> > +                                 const struct fuse_lowlevel_ops *op,
> > +                                 size_t op_size, void *userdata)
> > +{
> > +   int err;
> > +   struct fuse_session *se;
> > +   struct mount_opts *mo;
> > +
> > +   if (sizeof(struct fuse_lowlevel_ops) < op_size) {
> > +           fuse_log(FUSE_LOG_ERR, "fuse: warning: library too old, some 
> > operations may not work\n");
> > +           op_size = sizeof(struct fuse_lowlevel_ops);
> > +   }
> > +
> > +   if (args->argc == 0) {
> > +           fuse_log(FUSE_LOG_ERR, "fuse: empty argv passed to 
> > fuse_session_new().\n");
> > +           return NULL;
> > +   }
> > +
> > +   se = (struct fuse_session *) calloc(1, sizeof(struct fuse_session));
> > +   if (se == NULL) {
> > +           fuse_log(FUSE_LOG_ERR, "fuse: failed to allocate fuse 
> > object\n");
> > +           goto out1;
> > +   }
> > +   se->fd = -1;
> > +   se->conn.max_write = UINT_MAX;
> > +   se->conn.max_readahead = UINT_MAX;
> > +
> > +   /* Parse options */
> > +   if(fuse_opt_parse(args, se, fuse_ll_opts, NULL) == -1)
> > +           goto out2;
> > +   if(se->deny_others) {
> > +           /* Allowing access only by root is done by instructing
> > +            * kernel to allow access by everyone, and then restricting
> > +            * access to root and mountpoint owner in libfuse.
> > +            */
> > +           // We may be adding the option a second time, but
> > +           // that doesn't hurt.
> > +           if(fuse_opt_add_arg(args, "-oallow_other") == -1)
> > +                   goto out2;
> > +   }
> > +   mo = parse_mount_opts(args);
> > +   if (mo == NULL)
> > +           goto out3;
> > +
> > +   if(args->argc == 1 &&
> > +      args->argv[0][0] == '-') {
> > +           fuse_log(FUSE_LOG_ERR, "fuse: warning: argv[0] looks like an 
> > option, but "
> > +                   "will be ignored\n");
> > +   } else if (args->argc != 1) {
> > +           int i;
> > +           fuse_log(FUSE_LOG_ERR, "fuse: unknown option(s): `");
> > +           for(i = 1; i < args->argc-1; i++)
> > +                   fuse_log(FUSE_LOG_ERR, "%s ", args->argv[i]);
> > +           fuse_log(FUSE_LOG_ERR, "%s'\n", args->argv[i]);
> > +           goto out4;
> > +   }
> > +
> > +   if (se->debug)
> > +           fuse_log(FUSE_LOG_DEBUG, "FUSE library version: %s\n", 
> > PACKAGE_VERSION);
> > +
> > +   se->bufsize = FUSE_MAX_MAX_PAGES * getpagesize() +
> > +           FUSE_BUFFER_HEADER_SIZE;
> > +
> > +   list_init_req(&se->list);
> > +   list_init_req(&se->interrupts);
> > +   list_init_nreq(&se->notify_list);
> > +   se->notify_ctr = 1;
> > +   fuse_mutex_init(&se->lock);
> > +
> > +   err = pthread_key_create(&se->pipe_key, fuse_ll_pipe_destructor);
> > +   if (err) {
> > +           fuse_log(FUSE_LOG_ERR, "fuse: failed to create thread specific 
> > key: %s\n",
> > +                   strerror(err));
> > +           goto out5;
> > +   }
> > +
> > +   memcpy(&se->op, op, op_size);
> > +   se->owner = getuid();
> > +   se->userdata = userdata;
> > +
> > +   se->mo = mo;
> > +   return se;
> > +
> > +out5:
> > +   pthread_mutex_destroy(&se->lock);
> > +out4:
> > +   fuse_opt_free_args(args);
> > +out3:
> > +   free(mo);
> > +out2:
> > +   free(se);
> > +out1:
> > +   return NULL;
> > +}
> > +
> > +int fuse_session_mount(struct fuse_session *se, const char *mountpoint)
> > +{
> > +   int fd;
> > +
> > +   /*
> > +    * Make sure file descriptors 0, 1 and 2 are open, otherwise chaos
> > +    * would ensue.
> > +    */
> > +   do {
> > +           fd = open("/dev/null", O_RDWR);
> > +           if (fd > 2)
> > +                   close(fd);
> > +   } while (fd >= 0 && fd <= 2);
> > +
> > +   /*
> > +    * To allow FUSE daemons to run without privileges, the caller may open
> > +    * /dev/fuse before launching the file system and pass on the file
> > +    * descriptor by specifying /dev/fd/N as the mount point. Note that the
> > +    * parent process takes care of performing the mount in this case.
> > +    */
> > +   fd = fuse_mnt_parse_fuse_fd(mountpoint);
> > +   if (fd != -1) {
> > +           if (fcntl(fd, F_GETFD) == -1) {
> > +                   fuse_log(FUSE_LOG_ERR,
> > +                           "fuse: Invalid file descriptor /dev/fd/%u\n",
> > +                           fd);
> > +                   return -1;
> > +           }
> > +           se->fd = fd;
> > +           return 0;
> > +   }
> > +
> > +   /* Open channel */
> > +   fd = fuse_kern_mount(mountpoint, se->mo);
> > +   if (fd == -1)
> > +           return -1;
> > +   se->fd = fd;
> > +
> > +   /* Save mountpoint */
> > +   se->mountpoint = strdup(mountpoint);
> > +   if (se->mountpoint == NULL)
> > +           goto error_out;
> > +
> > +   return 0;
> > +
> > +error_out:
> > +   fuse_kern_unmount(mountpoint, fd);
> > +   return -1;
> > +}
> > +
> > +int fuse_session_fd(struct fuse_session *se)
> > +{
> > +   return se->fd;
> > +}
> > +
> > +void fuse_session_unmount(struct fuse_session *se)
> > +{
> > +   if (se->mountpoint != NULL) {
> > +           fuse_kern_unmount(se->mountpoint, se->fd);
> > +           free(se->mountpoint);
> > +           se->mountpoint = NULL;
> > +   }
> > +}
> > +
> > +#ifdef linux
> > +int fuse_req_getgroups(fuse_req_t req, int size, gid_t list[])
> > +{
> > +   char *buf;
> > +   size_t bufsize = 1024;
> > +   char path[128];
> > +   int ret;
> > +   int fd;
> > +   unsigned long pid = req->ctx.pid;
> > +   char *s;
> > +
> > +   sprintf(path, "/proc/%lu/task/%lu/status", pid, pid);
> > +
> > +retry:
> > +   buf = malloc(bufsize);
> > +   if (buf == NULL)
> > +           return -ENOMEM;
> > +
> > +   ret = -EIO;
> > +   fd = open(path, O_RDONLY);
> > +   if (fd == -1)
> > +           goto out_free;
> > +
> > +   ret = read(fd, buf, bufsize);
> > +   close(fd);
> > +   if (ret < 0) {
> > +           ret = -EIO;
> > +           goto out_free;
> > +   }
> > +
> > +   if ((size_t)ret == bufsize) {
> > +           free(buf);
> > +           bufsize *= 4;
> > +           goto retry;
> > +   }
> > +
> > +   ret = -EIO;
> > +   s = strstr(buf, "\nGroups:");
> > +   if (s == NULL)
> > +           goto out_free;
> > +
> > +   s += 8;
> > +   ret = 0;
> > +   while (1) {
> > +           char *end;
> > +           unsigned long val = strtoul(s, &end, 0);
> > +           if (end == s)
> > +                   break;
> > +
> > +           s = end;
> > +           if (ret < size)
> > +                   list[ret] = val;
> > +           ret++;
> > +   }
> > +
> > +out_free:
> > +   free(buf);
> > +   return ret;
> > +}
> > +#else /* linux */
> > +/*
> > + * This is currently not implemented on other than Linux...
> > + */
> > +int fuse_req_getgroups(fuse_req_t req, int size, gid_t list[])
> > +{
> > +   (void) req; (void) size; (void) list;
> > +   return -ENOSYS;
> > +}
> > +#endif
> > +
> > +void fuse_session_exit(struct fuse_session *se)
> > +{
> > +   se->exited = 1;
> > +}
> > +
> > +void fuse_session_reset(struct fuse_session *se)
> > +{
> > +   se->exited = 0;
> > +   se->error = 0;
> > +}
> > +
> > +int fuse_session_exited(struct fuse_session *se)
> > +{
> > +   return se->exited;
> > +}
> > -- 
> > 2.23.0
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK




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