diff options
Diffstat (limited to 'tools/virtiofsd/buffer.c')
| -rw-r--r-- | tools/virtiofsd/buffer.c | 350 |
1 files changed, 0 insertions, 350 deletions
diff --git a/tools/virtiofsd/buffer.c b/tools/virtiofsd/buffer.c deleted file mode 100644 index b5f04be356..0000000000 --- a/tools/virtiofsd/buffer.c +++ /dev/null @@ -1,350 +0,0 @@ -/* - * FUSE: Filesystem in Userspace - * Copyright (C) 2010 Miklos Szeredi <miklos@szeredi.hu> - * - * Functions for dealing with `struct fuse_buf` and `struct - * fuse_bufvec`. - * - * This program can be distributed under the terms of the GNU LGPLv2. - * See the file COPYING.LIB - */ - -#include "qemu/osdep.h" -#include "fuse_i.h" -#include "fuse_lowlevel.h" - -size_t fuse_buf_size(const struct fuse_bufvec *bufv) -{ - size_t i; - size_t size = 0; - - for (i = 0; i < bufv->count; i++) { - if (bufv->buf[i].size == SIZE_MAX) { - size = SIZE_MAX; - } else { - size += bufv->buf[i].size; - } - } - - return size; -} - -static ssize_t fuse_buf_writev(struct fuse_buf *out_buf, - struct fuse_bufvec *in_buf) -{ - ssize_t res, i, j; - size_t iovcnt = in_buf->count; - struct iovec *iov; - int fd = out_buf->fd; - - iov = g_try_new0(struct iovec, iovcnt); - if (!iov) { - return -ENOMEM; - } - - for (i = 0, j = 0; i < iovcnt; i++) { - /* Skip the buf with 0 size */ - if (in_buf->buf[i].size) { - iov[j].iov_base = in_buf->buf[i].mem; - iov[j].iov_len = in_buf->buf[i].size; - j++; - } - } - - if (out_buf->flags & FUSE_BUF_FD_SEEK) { - res = pwritev(fd, iov, iovcnt, out_buf->pos); - } else { - res = writev(fd, iov, iovcnt); - } - - if (res == -1) { - res = -errno; - } - - g_free(iov); - return res; -} - -static size_t min_size(size_t s1, size_t s2) -{ - return s1 < s2 ? s1 : s2; -} - -static ssize_t fuse_buf_write(const struct fuse_buf *dst, size_t dst_off, - const struct fuse_buf *src, size_t src_off, - size_t len) -{ - ssize_t res = 0; - size_t copied = 0; - - while (len) { - if (dst->flags & FUSE_BUF_FD_SEEK) { - res = pwrite(dst->fd, (char *)src->mem + src_off, len, - dst->pos + dst_off); - } else { - res = write(dst->fd, (char *)src->mem + src_off, len); - } - if (res == -1) { - if (!copied) { - return -errno; - } - break; - } - if (res == 0) { - break; - } - - copied += res; - if (!(dst->flags & FUSE_BUF_FD_RETRY)) { - break; - } - - src_off += res; - dst_off += res; - len -= res; - } - - return copied; -} - -static ssize_t fuse_buf_read(const struct fuse_buf *dst, size_t dst_off, - const struct fuse_buf *src, size_t src_off, - size_t len) -{ - ssize_t res = 0; - size_t copied = 0; - - while (len) { - if (src->flags & FUSE_BUF_FD_SEEK) { - res = pread(src->fd, (char *)dst->mem + dst_off, len, - src->pos + src_off); - } else { - res = read(src->fd, (char *)dst->mem + dst_off, len); - } - if (res == -1) { - if (!copied) { - return -errno; - } - break; - } - if (res == 0) { - break; - } - - copied += res; - if (!(src->flags & FUSE_BUF_FD_RETRY)) { - break; - } - - dst_off += res; - src_off += res; - len -= res; - } - - return copied; -} - -static ssize_t fuse_buf_fd_to_fd(const struct fuse_buf *dst, size_t dst_off, - const struct fuse_buf *src, size_t src_off, - size_t len) -{ - char buf[4096]; - struct fuse_buf tmp = { - .size = sizeof(buf), - .flags = 0, - }; - ssize_t res; - size_t copied = 0; - - tmp.mem = buf; - - while (len) { - size_t this_len = min_size(tmp.size, len); - size_t read_len; - - res = fuse_buf_read(&tmp, 0, src, src_off, this_len); - if (res < 0) { - if (!copied) { - return res; - } - break; - } - if (res == 0) { - break; - } - - read_len = res; - res = fuse_buf_write(dst, dst_off, &tmp, 0, read_len); - if (res < 0) { - if (!copied) { - return res; - } - break; - } - if (res == 0) { - break; - } - - copied += res; - - if (res < this_len) { - break; - } - - dst_off += res; - src_off += res; - len -= res; - } - - return copied; -} - -static ssize_t fuse_buf_copy_one(const struct fuse_buf *dst, size_t dst_off, - const struct fuse_buf *src, size_t src_off, - size_t len) -{ - int src_is_fd = src->flags & FUSE_BUF_IS_FD; - int dst_is_fd = dst->flags & FUSE_BUF_IS_FD; - - if (!src_is_fd && !dst_is_fd) { - char *dstmem = (char *)dst->mem + dst_off; - char *srcmem = (char *)src->mem + src_off; - - if (dstmem != srcmem) { - if (dstmem + len <= srcmem || srcmem + len <= dstmem) { - memcpy(dstmem, srcmem, len); - } else { - memmove(dstmem, srcmem, len); - } - } - - return len; - } else if (!src_is_fd) { - return fuse_buf_write(dst, dst_off, src, src_off, len); - } else if (!dst_is_fd) { - return fuse_buf_read(dst, dst_off, src, src_off, len); - } else { - return fuse_buf_fd_to_fd(dst, dst_off, src, src_off, len); - } -} - -static const struct fuse_buf *fuse_bufvec_current(struct fuse_bufvec *bufv) -{ - if (bufv->idx < bufv->count) { - return &bufv->buf[bufv->idx]; - } else { - return NULL; - } -} - -static int fuse_bufvec_advance(struct fuse_bufvec *bufv, size_t len) -{ - const struct fuse_buf *buf = fuse_bufvec_current(bufv); - - if (!buf) { - return 0; - } - - bufv->off += len; - assert(bufv->off <= buf->size); - if (bufv->off == buf->size) { - assert(bufv->idx < bufv->count); - bufv->idx++; - if (bufv->idx == bufv->count) { - return 0; - } - bufv->off = 0; - } - return 1; -} - -ssize_t fuse_buf_copy(struct fuse_bufvec *dstv, struct fuse_bufvec *srcv) -{ - size_t copied = 0, i; - - if (dstv == srcv) { - return fuse_buf_size(dstv); - } - - /* - * use writev to improve bandwidth when all the - * src buffers already mapped by the daemon - * process - */ - for (i = 0; i < srcv->count; i++) { - if (srcv->buf[i].flags & FUSE_BUF_IS_FD) { - break; - } - } - if ((i == srcv->count) && (dstv->count == 1) && - (dstv->idx == 0) && - (dstv->buf[0].flags & FUSE_BUF_IS_FD)) { - dstv->buf[0].pos += dstv->off; - return fuse_buf_writev(&dstv->buf[0], srcv); - } - - for (;;) { - const struct fuse_buf *src = fuse_bufvec_current(srcv); - const struct fuse_buf *dst = fuse_bufvec_current(dstv); - size_t src_len; - size_t dst_len; - size_t len; - ssize_t res; - - if (src == NULL || dst == NULL) { - break; - } - - src_len = src->size - srcv->off; - dst_len = dst->size - dstv->off; - len = min_size(src_len, dst_len); - - res = fuse_buf_copy_one(dst, dstv->off, src, srcv->off, len); - if (res < 0) { - if (!copied) { - return res; - } - break; - } - copied += res; - - if (!fuse_bufvec_advance(srcv, res) || - !fuse_bufvec_advance(dstv, res)) { - break; - } - - if (res < len) { - break; - } - } - - return copied; -} - -void *fuse_mbuf_iter_advance(struct fuse_mbuf_iter *iter, size_t len) -{ - void *ptr; - - if (len > iter->size - iter->pos) { - return NULL; - } - - ptr = iter->mem + iter->pos; - iter->pos += len; - return ptr; -} - -const char *fuse_mbuf_iter_advance_str(struct fuse_mbuf_iter *iter) -{ - const char *str = iter->mem + iter->pos; - size_t remaining = iter->size - iter->pos; - size_t i; - - for (i = 0; i < remaining; i++) { - if (str[i] == '\0') { - iter->pos += i + 1; - return str; - } - } - return NULL; -} |