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authorPeter Lieven <pl@kamp.de>2015-03-03 11:41:56 +0100
committerMax Reitz <mreitz@redhat.com>2015-03-16 12:10:30 -0400
commit304ee9174f4761d3f4da611352a815ab27baba06 (patch)
tree3aea3c10cc10a200a511a845d7b42222e7c6d12a
parent03671ded3078ebad1f0a701042622fd5e8918bc9 (diff)
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block/vpc: remove disabled code from get_sector_offset
The code to check the bitmap for the allocation status of each sector has been "disabled by reason" ever since the vpc driver existed. The reason might be that we might end up reading sector by sector in vpc_read if we really used it. This would be a performance desaster. The current code would furthermore not work if the disabled parts get reactivated since vpc_read and vpc_write only use get_sector_offset to check the allocation status of the first sector of a read/write operation. This might lead to sectors incorrectly treated as zero in vpc_read and to sectors getting allocated twice in vpc_write. Signed-off-by: Peter Lieven <pl@kamp.de> Message-id: 1425379316-19639-6-git-send-email-pl@kamp.de Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
-rw-r--r--block/vpc.c32
1 files changed, 0 insertions, 32 deletions
diff --git a/block/vpc.c b/block/vpc.c
index 226be02..43e768e 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -376,38 +376,6 @@ static inline int64_t get_sector_offset(BlockDriverState *bs,
bdrv_pwrite_sync(bs->file, bitmap_offset, bitmap, s->bitmap_size);
}
-// printf("sector: %" PRIx64 ", index: %x, offset: %x, bioff: %" PRIx64 ", bloff: %" PRIx64 "\n",
-// sector_num, pagetable_index, pageentry_index,
-// bitmap_offset, block_offset);
-
-// disabled by reason
-#if 0
-#ifdef CACHE
- if (bitmap_offset != s->last_bitmap)
- {
- lseek(s->fd, bitmap_offset, SEEK_SET);
-
- s->last_bitmap = bitmap_offset;
-
- // Scary! Bitmap is stored as big endian 32bit entries,
- // while we used to look it up byte by byte
- read(s->fd, s->pageentry_u8, 512);
- for (i = 0; i < 128; i++)
- be32_to_cpus(&s->pageentry_u32[i]);
- }
-
- if ((s->pageentry_u8[pageentry_index / 8] >> (pageentry_index % 8)) & 1)
- return -1;
-#else
- lseek(s->fd, bitmap_offset + (pageentry_index / 8), SEEK_SET);
-
- read(s->fd, &bitmap_entry, 1);
-
- if ((bitmap_entry >> (pageentry_index % 8)) & 1)
- return -1; // not allocated
-#endif
-#endif
-
return block_offset;
}