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virtiofsd: Add auxiliary .c's
Add most of the non-main .c files we need from upstream fuse-3.8.0 Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This commit is contained in:
Dr. David Alan Gilbert
parent
a62a9e192b
commit
ffcf8d9f86
5 changed files with 1315 additions and 0 deletions
321
tools/virtiofsd/buffer.c
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321
tools/virtiofsd/buffer.c
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/*
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FUSE: Filesystem in Userspace
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Copyright (C) 2010 Miklos Szeredi <miklos@szeredi.hu>
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Functions for dealing with `struct fuse_buf` and `struct
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fuse_bufvec`.
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This program can be distributed under the terms of the GNU LGPLv2.
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See the file COPYING.LIB
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*/
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#define _GNU_SOURCE
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#include "config.h"
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#include "fuse_i.h"
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#include "fuse_lowlevel.h"
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#include <string.h>
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#include <unistd.h>
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#include <errno.h>
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#include <assert.h>
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size_t fuse_buf_size(const struct fuse_bufvec *bufv)
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{
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size_t i;
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size_t size = 0;
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for (i = 0; i < bufv->count; i++) {
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if (bufv->buf[i].size == SIZE_MAX)
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size = SIZE_MAX;
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else
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size += bufv->buf[i].size;
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}
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return size;
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}
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static size_t min_size(size_t s1, size_t s2)
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{
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return s1 < s2 ? s1 : s2;
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}
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static ssize_t fuse_buf_write(const struct fuse_buf *dst, size_t dst_off,
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const struct fuse_buf *src, size_t src_off,
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size_t len)
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{
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ssize_t res = 0;
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size_t copied = 0;
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while (len) {
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if (dst->flags & FUSE_BUF_FD_SEEK) {
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res = pwrite(dst->fd, (char *)src->mem + src_off, len,
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dst->pos + dst_off);
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} else {
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res = write(dst->fd, (char *)src->mem + src_off, len);
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}
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if (res == -1) {
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if (!copied)
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return -errno;
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break;
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}
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if (res == 0)
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break;
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copied += res;
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if (!(dst->flags & FUSE_BUF_FD_RETRY))
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break;
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src_off += res;
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dst_off += res;
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len -= res;
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}
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return copied;
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}
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static ssize_t fuse_buf_read(const struct fuse_buf *dst, size_t dst_off,
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const struct fuse_buf *src, size_t src_off,
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size_t len)
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{
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ssize_t res = 0;
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size_t copied = 0;
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while (len) {
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if (src->flags & FUSE_BUF_FD_SEEK) {
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res = pread(src->fd, (char *)dst->mem + dst_off, len,
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src->pos + src_off);
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} else {
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res = read(src->fd, (char *)dst->mem + dst_off, len);
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}
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if (res == -1) {
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if (!copied)
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return -errno;
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break;
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}
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if (res == 0)
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break;
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copied += res;
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if (!(src->flags & FUSE_BUF_FD_RETRY))
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break;
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dst_off += res;
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src_off += res;
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len -= res;
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}
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return copied;
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}
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static ssize_t fuse_buf_fd_to_fd(const struct fuse_buf *dst, size_t dst_off,
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const struct fuse_buf *src, size_t src_off,
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size_t len)
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{
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char buf[4096];
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struct fuse_buf tmp = {
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.size = sizeof(buf),
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.flags = 0,
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};
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ssize_t res;
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size_t copied = 0;
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tmp.mem = buf;
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while (len) {
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size_t this_len = min_size(tmp.size, len);
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size_t read_len;
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res = fuse_buf_read(&tmp, 0, src, src_off, this_len);
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if (res < 0) {
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if (!copied)
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return res;
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break;
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}
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if (res == 0)
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break;
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read_len = res;
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res = fuse_buf_write(dst, dst_off, &tmp, 0, read_len);
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if (res < 0) {
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if (!copied)
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return res;
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break;
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}
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if (res == 0)
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break;
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copied += res;
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if (res < this_len)
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break;
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dst_off += res;
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src_off += res;
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len -= res;
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}
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return copied;
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}
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#ifdef HAVE_SPLICE
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static ssize_t fuse_buf_splice(const struct fuse_buf *dst, size_t dst_off,
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const struct fuse_buf *src, size_t src_off,
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size_t len, enum fuse_buf_copy_flags flags)
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{
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int splice_flags = 0;
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off_t *srcpos = NULL;
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off_t *dstpos = NULL;
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off_t srcpos_val;
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off_t dstpos_val;
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ssize_t res;
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size_t copied = 0;
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if (flags & FUSE_BUF_SPLICE_MOVE)
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splice_flags |= SPLICE_F_MOVE;
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if (flags & FUSE_BUF_SPLICE_NONBLOCK)
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splice_flags |= SPLICE_F_NONBLOCK;
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if (src->flags & FUSE_BUF_FD_SEEK) {
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srcpos_val = src->pos + src_off;
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srcpos = &srcpos_val;
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}
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if (dst->flags & FUSE_BUF_FD_SEEK) {
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dstpos_val = dst->pos + dst_off;
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dstpos = &dstpos_val;
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}
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while (len) {
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res = splice(src->fd, srcpos, dst->fd, dstpos, len,
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splice_flags);
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if (res == -1) {
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if (copied)
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break;
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if (errno != EINVAL || (flags & FUSE_BUF_FORCE_SPLICE))
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return -errno;
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/* Maybe splice is not supported for this combination */
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return fuse_buf_fd_to_fd(dst, dst_off, src, src_off,
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len);
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}
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if (res == 0)
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break;
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copied += res;
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if (!(src->flags & FUSE_BUF_FD_RETRY) &&
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!(dst->flags & FUSE_BUF_FD_RETRY)) {
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break;
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}
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len -= res;
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}
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return copied;
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}
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#else
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static ssize_t fuse_buf_splice(const struct fuse_buf *dst, size_t dst_off,
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const struct fuse_buf *src, size_t src_off,
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size_t len, enum fuse_buf_copy_flags flags)
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{
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(void) flags;
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return fuse_buf_fd_to_fd(dst, dst_off, src, src_off, len);
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}
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#endif
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static ssize_t fuse_buf_copy_one(const struct fuse_buf *dst, size_t dst_off,
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const struct fuse_buf *src, size_t src_off,
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size_t len, enum fuse_buf_copy_flags flags)
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{
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int src_is_fd = src->flags & FUSE_BUF_IS_FD;
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int dst_is_fd = dst->flags & FUSE_BUF_IS_FD;
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if (!src_is_fd && !dst_is_fd) {
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char *dstmem = (char *)dst->mem + dst_off;
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char *srcmem = (char *)src->mem + src_off;
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if (dstmem != srcmem) {
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if (dstmem + len <= srcmem || srcmem + len <= dstmem)
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memcpy(dstmem, srcmem, len);
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else
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memmove(dstmem, srcmem, len);
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}
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return len;
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} else if (!src_is_fd) {
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return fuse_buf_write(dst, dst_off, src, src_off, len);
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} else if (!dst_is_fd) {
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return fuse_buf_read(dst, dst_off, src, src_off, len);
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} else if (flags & FUSE_BUF_NO_SPLICE) {
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return fuse_buf_fd_to_fd(dst, dst_off, src, src_off, len);
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} else {
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return fuse_buf_splice(dst, dst_off, src, src_off, len, flags);
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}
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}
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static const struct fuse_buf *fuse_bufvec_current(struct fuse_bufvec *bufv)
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{
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if (bufv->idx < bufv->count)
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return &bufv->buf[bufv->idx];
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else
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return NULL;
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}
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static int fuse_bufvec_advance(struct fuse_bufvec *bufv, size_t len)
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{
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const struct fuse_buf *buf = fuse_bufvec_current(bufv);
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bufv->off += len;
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assert(bufv->off <= buf->size);
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if (bufv->off == buf->size) {
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assert(bufv->idx < bufv->count);
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bufv->idx++;
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if (bufv->idx == bufv->count)
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return 0;
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bufv->off = 0;
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}
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return 1;
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}
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ssize_t fuse_buf_copy(struct fuse_bufvec *dstv, struct fuse_bufvec *srcv,
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enum fuse_buf_copy_flags flags)
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{
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size_t copied = 0;
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if (dstv == srcv)
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return fuse_buf_size(dstv);
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for (;;) {
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const struct fuse_buf *src = fuse_bufvec_current(srcv);
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const struct fuse_buf *dst = fuse_bufvec_current(dstv);
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size_t src_len;
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size_t dst_len;
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size_t len;
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ssize_t res;
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if (src == NULL || dst == NULL)
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break;
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src_len = src->size - srcv->off;
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dst_len = dst->size - dstv->off;
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len = min_size(src_len, dst_len);
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res = fuse_buf_copy_one(dst, dstv->off, src, srcv->off, len, flags);
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if (res < 0) {
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if (!copied)
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return res;
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break;
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}
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copied += res;
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if (!fuse_bufvec_advance(srcv, res) ||
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!fuse_bufvec_advance(dstv, res))
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break;
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if (res < len)
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break;
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}
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return copied;
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}
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