Re: [Qemu-devel] [PATCH 3/3] slirp: improve TFTP performance

[Aurelien Jarno]

On Mon, Apr 11, 2011 at 07:10:54PM +0000, Herve Poussineau wrote:
> From: Herv? Poussineau <address@hidden>
> 
> When transfering a file, keep it open during the whole transfer,
> instead of opening/closing it for each block.
> 
> Signed-off-by: Herv? Poussineau <address@hidden>
> ---
>  slirp/tftp.c |   20 ++++++++++++--------
>  slirp/tftp.h |    1 +
>  2 files changed, 13 insertions(+), 8 deletions(-)
> 
> diff --git a/slirp/tftp.c b/slirp/tftp.c
> index 7e63269..48748f1 100644
> --- a/slirp/tftp.c
> +++ b/slirp/tftp.c
> @@ -37,6 +37,10 @@ static inline void tftp_session_update(struct tftp_session 
> *spt)
>  
>  static void tftp_session_terminate(struct tftp_session *spt)
>  {
> +    if (spt->fd >= 0) {
> +        close(spt->fd);
> +        spt->fd = -1;
> +    }
>      qemu_free(spt->filename);
>      spt->slirp = NULL;
>  }
> @@ -54,7 +58,7 @@ static int tftp_session_allocate(Slirp *slirp, struct 
> tftp_t *tp)
>  
>      /* sessions time out after 5 inactive seconds */
>      if ((int)(curtime - spt->timestamp) > 5000) {
> -        qemu_free(spt->filename);
> +        tftp_session_terminate(spt);
>          goto found;
>      }
>    }
> @@ -64,6 +68,7 @@ static int tftp_session_allocate(Slirp *slirp, struct 
> tftp_t *tp)
>   found:
>    memset(spt, 0, sizeof(*spt));
>    memcpy(&spt->client_ip, &tp->ip.ip_src, sizeof(spt->client_ip));
> +  spt->fd = -1;
>    spt->client_port = tp->udp.uh_sport;
>    spt->slirp = slirp;
>  
> @@ -95,23 +100,22 @@ static int tftp_session_find(Slirp *slirp, struct tftp_t 
> *tp)
>  static int tftp_read_data(struct tftp_session *spt, uint32_t block_nr,
>                            uint8_t *buf, int len)
>  {
> -  int fd;
>    int bytes_read = 0;
>  
> -  fd = open(spt->filename, O_RDONLY | O_BINARY);
> +  if (spt->fd < 0) {
> +    spt->fd = open(spt->filename, O_RDONLY | O_BINARY);
> +  }
>  
> -  if (fd < 0) {
> +  if (spt->fd < 0) {
>      return -1;
>    }
>  
>    if (len) {
> -    lseek(fd, block_nr * 512, SEEK_SET);
> +    lseek(spt->fd, block_nr * 512, SEEK_SET);
>  
> -    bytes_read = read(fd, buf, len);
> +    bytes_read = read(spt->fd, buf, len);
>    }
>  
> -  close(fd);
> -
>    return bytes_read;
>  }

Given you are rewriting this most of this function, it's probably the
good moment to also fix the indentation to 4 spaces.

> diff --git a/slirp/tftp.h b/slirp/tftp.h
> index 471f22e..51704e4 100644
> --- a/slirp/tftp.h
> +++ b/slirp/tftp.h
> @@ -33,6 +33,7 @@ struct tftp_t {
>  struct tftp_session {
>      Slirp *slirp;
>      char *filename;
> +    int fd;
>  
>      struct in_addr client_ip;
>      uint16_t client_port;
> -- 
> 1.6.0.2.GIT
> 

Except the minor nit above:

Reviewed-by: Aurelien Jarno <address@hidden>

-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
address@hidden                 http://www.aurel32.net