Commit 7b3f9712 authored by Eric Blake's avatar Eric Blake Committed by Kevin Wolf
Browse files

qemu-io: Switch to byte-based block access 



qemu-io is the last user of several sector-based interfaces.
This patch upgrades to the new interfaces under the hood,
then deletes the resulting dead code.  Note that for maximum
back-compat, while the -p option is no longer required to get
blk_pread(), it is still needed to allow for unaligned access;
this is because qemu-iotest 23 relies on qemu-io rejecting
unaligned accesses without -p.  A later patch may clean up the
interface to be more user-friendly, but it's better to separate
what's done under the hood from what the user sees.

Signed-off-by: default avatarEric Blake <eblake@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 9166920a

qemu-io-cmds.c

+10 −52
Original line number Diff line number Diff line
@@ -419,40 +419,6 @@ fail: 
    return buf;

}



static int do_read(BlockBackend *blk, char *buf, int64_t offset, int64_t count,

                   int64_t *total)

{

    int ret;



    if (count >> 9 > INT_MAX) {

        return -ERANGE;

    }



    ret = blk_read(blk, offset >> 9, (uint8_t *)buf, count >> 9);

    if (ret < 0) {

        return ret;

    }

    *total = count;

    return 1;

}



static int do_write(BlockBackend *blk, char *buf, int64_t offset, int64_t count,

                    int64_t *total)

{

    int ret;



    if (count >> 9 > INT_MAX) {

        return -ERANGE;

    }



    ret = blk_write(blk, offset >> 9, (uint8_t *)buf, count >> 9);

    if (ret < 0) {

        return ret;

    }

    *total = count;

    return 1;

}



static int do_pread(BlockBackend *blk, char *buf, int64_t offset,

                    int64_t count, int64_t *total)

{
@@ -588,8 +554,7 @@ static int do_aio_readv(BlockBackend *blk, QEMUIOVector *qiov, 
{

    int async_ret = NOT_DONE;



    blk_aio_readv(blk, offset >> 9, qiov, qiov->size >> 9,

                  aio_rw_done, &async_ret);

    blk_aio_preadv(blk, offset, qiov, 0, aio_rw_done, &async_ret);

    while (async_ret == NOT_DONE) {

        main_loop_wait(false);

    }
@@ -603,8 +568,7 @@ static int do_aio_writev(BlockBackend *blk, QEMUIOVector *qiov, 
{

    int async_ret = NOT_DONE;



    blk_aio_writev(blk, offset >> 9, qiov, qiov->size >> 9,

                   aio_rw_done, &async_ret);

    blk_aio_pwritev(blk, offset, qiov, 0, aio_rw_done, &async_ret);

    while (async_ret == NOT_DONE) {

        main_loop_wait(false);

    }
@@ -670,7 +634,7 @@ static void read_help(void) 
" -b, -- read from the VM state rather than the virtual disk\n"

" -C, -- report statistics in a machine parsable format\n"

" -l, -- length for pattern verification (only with -P)\n"

" -p, -- use blk_pread to read the file\n"

" -p, -- allow unaligned access\n"

" -P, -- use a pattern to verify read data\n"

" -q, -- quiet mode, do not show I/O statistics\n"

" -s, -- start offset for pattern verification (only with -P)\n"
@@ -805,12 +769,10 @@ static int read_f(BlockBackend *blk, int argc, char **argv) 
    buf = qemu_io_alloc(blk, count, 0xab);



    gettimeofday(&t1, NULL);

    if (pflag) {

        cnt = do_pread(blk, buf, offset, count, &total);

    } else if (bflag) {

    if (bflag) {

        cnt = do_load_vmstate(blk, buf, offset, count, &total);

    } else {

        cnt = do_read(blk, buf, offset, count, &total);

        cnt = do_pread(blk, buf, offset, count, &total);

    }

    gettimeofday(&t2, NULL);
@@ -990,7 +952,7 @@ static void write_help(void) 
" filled with a set pattern (0xcdcdcdcd).\n"

" -b, -- write to the VM state rather than the virtual disk\n"

" -c, -- write compressed data with blk_write_compressed\n"

" -p, -- use blk_pwrite to write the file\n"

" -p, -- allow unaligned access\n"

" -P, -- use different pattern to fill file\n"

" -C, -- report statistics in a machine parsable format\n"

" -q, -- quiet mode, do not show I/O statistics\n"
@@ -1106,16 +1068,14 @@ static int write_f(BlockBackend *blk, int argc, char **argv) 
    }



    gettimeofday(&t1, NULL);

    if (pflag) {

        cnt = do_pwrite(blk, buf, offset, count, &total);

    } else if (bflag) {

    if (bflag) {

        cnt = do_save_vmstate(blk, buf, offset, count, &total);

    } else if (zflag) {

        cnt = do_co_write_zeroes(blk, offset, count, &total);

    } else if (cflag) {

        cnt = do_write_compressed(blk, buf, offset, count, &total);

    } else {

        cnt = do_write(blk, buf, offset, count, &total);

        cnt = do_pwrite(blk, buf, offset, count, &total);

    }

    gettimeofday(&t2, NULL);
@@ -1592,8 +1552,7 @@ static int aio_read_f(BlockBackend *blk, int argc, char **argv) 
    gettimeofday(&ctx->t1, NULL);

    block_acct_start(blk_get_stats(blk), &ctx->acct, ctx->qiov.size,

                     BLOCK_ACCT_READ);

    blk_aio_readv(blk, ctx->offset >> 9, &ctx->qiov,

                  ctx->qiov.size >> 9, aio_read_done, ctx);

    blk_aio_preadv(blk, ctx->offset, &ctx->qiov, 0, aio_read_done, ctx);

    return 0;

}
@@ -1718,8 +1677,7 @@ static int aio_write_f(BlockBackend *blk, int argc, char **argv) 
        block_acct_start(blk_get_stats(blk), &ctx->acct, ctx->qiov.size,

                         BLOCK_ACCT_WRITE);



        blk_aio_writev(blk, ctx->offset >> 9, &ctx->qiov,

                       ctx->qiov.size >> 9, aio_write_done, ctx);

        blk_aio_pwritev(blk, ctx->offset, &ctx->qiov, 0, aio_write_done, ctx);

    }

    return 0;

}