[Xen-changelog] [xen-unstable] blktap: fix and use ROUNDUP macro (bug 1430 part 1)

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1244023864 -3600
# Node ID f989778298d8074ad9135f3a538d449b6baab947
# Parent  e7b63b30ae3da2c3184dfa6fc00a816f90a158d5
blktap: fix and use ROUNDUP macro (bug 1430 part 1)

As pointed out in Xen Bugzilla 1430 in the blktap QCOW driver the
rounding function is wrong in line 824 of block-qcow.c.
This patch replaces this (and other roundings) with the already
existing ROUNDUP macro (and fixes the usual macro pitfall).

Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
 tools/blktap/drivers/block-qcow.c |   12 ++++++------
 1 files changed, 6 insertions(+), 6 deletions(-)

diff -r e7b63b30ae3d -r f989778298d8 tools/blktap/drivers/block-qcow.c
--- a/tools/blktap/drivers/block-qcow.c Wed Jun 03 11:10:07 2009 +0100
+++ b/tools/blktap/drivers/block-qcow.c Wed Jun 03 11:11:04 2009 +0100
@@ -55,7 +55,7 @@
 #define ROUNDUP(l, s) \
 ({ \
     (uint64_t)( \
-        (l + (s - 1)) - ((l + (s - 1)) % s)); \
+        ((l) + ((s) - 1)) - (((l) + ((s) - 1)) % (s))); \
 })
 
 #undef IOCB_IDX
@@ -800,14 +800,14 @@ static int tdqcow_open (struct disk_driv
 
        /* read the level 1 table */
        shift = s->cluster_bits + s->l2_bits;
-       s->l1_size = (header->size + (1LL << shift) - 1) >> shift;
+       s->l1_size = ROUNDUP(header->size, 1LL << shift);
        
        s->l1_table_offset = header->l1_table_offset;
 
        /*allocate a 4Kbyte multiple of memory*/
        l1_table_size = s->l1_size * sizeof(uint64_t);
        if (l1_table_size % 4096 > 0) {
-               l1_table_size = ((l1_table_size >> 12) + 1) << 12;
+               l1_table_size = ROUNDUP(l1_table_size, 4096);
        }
        ret = posix_memalign((void **)&s->l1_table, 4096, l1_table_size);
        if (ret != 0) goto fail;
@@ -821,7 +821,7 @@ static int tdqcow_open (struct disk_driv
 
        lseek(fd, 0, SEEK_SET);
        l1_table_block = l1_table_size + s->l1_table_offset;
-       l1_table_block = l1_table_block + 512 - (l1_table_block % 512); 
+       l1_table_block = ROUNDUP(l1_table_block, 512);
        ret = posix_memalign((void **)&buf2, 4096, l1_table_block);
        if (ret != 0) goto fail;
        if (read(fd, buf2, l1_table_block) != l1_table_block)
@@ -1226,11 +1226,11 @@ int qcow_create(const char *filename, ui
        
        header_size = (header_size + 7) & ~7;
        if (header_size % 4096 > 0) {
-               header_size = ((header_size >> 12) + 1) << 12;
+               header_size = ROUNDUP(header_size, 4096);
        }
 
        shift = header.cluster_bits + header.l2_bits;
-       l1_size = ((size * 512) + (1LL << shift) - 1) >> shift;
+       l1_size = ROUNDUP(size * 512, 1LL << shift);
 
        header.l1_table_offset = cpu_to_be64(header_size);
        DPRINTF("L1 Table offset: %d, size %d\n",

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