[Cluster-devel] libgfs2: Add iovec to gfs2_buffer_head
Andrew Price
anprice at redhat.com
Fri Dec 16 20:25:22 UTC 2011
Hi,
On 16/12/11 14:24, Steven Whitehouse wrote:
>
> So that we keep track of buffer sizes, add an iovec to the
> gfs2_buffer_head structure. This uses an unnamed union in
> order to be backwards compatible with users of b_data.
>
> Signed-off-by: Steven Whitehouse<swhiteho at redhat.com>
Looks good to me,
Andy
>
> diff --git a/gfs2/libgfs2/buf.c b/gfs2/libgfs2/buf.c
> index 445b0ba..956dd8b 100644
> --- a/gfs2/libgfs2/buf.c
> +++ b/gfs2/libgfs2/buf.c
> @@ -24,7 +24,9 @@ struct gfs2_buffer_head *bget(struct gfs2_sbd *sdp, uint64_t num)
>
> bh->b_blocknr = num;
> bh->sdp = sdp;
> - bh->b_data = (char *)bh + sizeof(struct gfs2_buffer_head);
> + bh->iov.iov_base = (char *)bh + sizeof(struct gfs2_buffer_head);
> + bh->iov.iov_len = sdp->bsize;
> +
> return bh;
> }
>
> @@ -42,7 +44,7 @@ struct gfs2_buffer_head *__bread(struct gfs2_sbd *sdp, uint64_t num, int line,
> (unsigned long long)num);
> exit(-1);
> }
> - if (read(sdp->device_fd, bh->b_data, sdp->bsize)< 0) {
> + if (readv(sdp->device_fd,&bh->iov, 1)< 0) {
> fprintf(stderr, "bad read: %s from %s:%d: block "
> "%llu (0x%llx)\n", strerror(errno),
> caller, line, (unsigned long long)num,
> @@ -60,7 +62,7 @@ int bwrite(struct gfs2_buffer_head *bh)
> bh->b_blocknr * sdp->bsize) {
> return -1;
> }
> - if (write(sdp->device_fd, bh->b_data, sdp->bsize) != sdp->bsize)
> + if (writev(sdp->device_fd,&bh->iov, 1) != bh->iov.iov_len)
> return -1;
> sdp->writes++;
> bh->b_modified = 0;
> diff --git a/gfs2/libgfs2/libgfs2.h b/gfs2/libgfs2/libgfs2.h
> index 0e521fb..d5cac5a 100644
> --- a/gfs2/libgfs2/libgfs2.h
> +++ b/gfs2/libgfs2/libgfs2.h
> @@ -7,6 +7,7 @@
> #include<errno.h>
> #include<sys/types.h>
> #include<sys/stat.h>
> +#include<sys/uio.h>
> #include<linux/types.h>
> #include<linux/limits.h>
> #include<endian.h>
> @@ -111,7 +112,10 @@ struct gfs2_buffer_head {
> osi_list_t b_altlist; /* alternate list */
> uint64_t b_blocknr;
> int b_modified;
> - char *b_data;
> + union {
> + char *b_data;
> + struct iovec iov;
> + };
> struct gfs2_sbd *sdp;
> };
>
>
>
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