static ssize_t proxy_pwritev(FsContext *ctx, V9fsFidOpenState *fs, const struct iovec *iov, int iovcnt, off_t offset) { ssize_t ret; #ifdef CONFIG_PREADV ret = pwritev(fs->fd, iov, iovcnt, offset); #else ret = lseek(fs->fd, offset, SEEK_SET); if (ret >= 0) { ret = writev(fs->fd, iov, iovcnt); } #endif #ifdef CONFIG_SYNC_FILE_RANGE if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) { /* * Initiate a writeback. This is not a data integrity sync. * We want to ensure that we don't leave dirty pages in the cache * after write when writeout=immediate is sepcified. */ sync_file_range(fs->fd, offset, ret, SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE); } #endif return ret; }