diff options
Diffstat (limited to 'tools/virtiofsd/buffer.c')
| -rw-r--r-- | tools/virtiofsd/buffer.c | 434 |
1 files changed, 227 insertions, 207 deletions
diff --git a/tools/virtiofsd/buffer.c b/tools/virtiofsd/buffer.c index aefb7db..5df946c 100644 --- a/tools/virtiofsd/buffer.c +++ b/tools/virtiofsd/buffer.c @@ -1,252 +1,272 @@ /* - 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 -*/ + * 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 + */ #define _GNU_SOURCE #include "config.h" #include "fuse_i.h" #include "fuse_lowlevel.h" +#include <assert.h> +#include <errno.h> #include <string.h> #include <unistd.h> -#include <errno.h> -#include <assert.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; + 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 size_t min_size(size_t s1, size_t s2) { - return s1 < s2 ? s1 : 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) + 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; + 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) + 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; + 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) + 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; + 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, enum fuse_buf_copy_flags flags) + const struct fuse_buf *src, size_t src_off, + size_t len, enum fuse_buf_copy_flags flags) { - 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); - } + 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; + 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); - - 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; + const struct fuse_buf *buf = fuse_bufvec_current(bufv); + + 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, - enum fuse_buf_copy_flags flags) + enum fuse_buf_copy_flags flags) { - size_t copied = 0; - - if (dstv == srcv) - return fuse_buf_size(dstv); - - 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, flags); - 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; + size_t copied = 0; + + if (dstv == srcv) { + return fuse_buf_size(dstv); + } + + 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, flags); + 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; } |