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[Qemu-devel] [PULL 28/42] block/dmg: use SectorNumber from BLKX header
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PULL 28/42] block/dmg: use SectorNumber from BLKX header |
Date: |
Fri, 6 Feb 2015 17:40:35 +0100 |
From: Peter Wu <address@hidden>
Previously the sector table parsing relied on the previous offset of
the DMG file. Now it uses the sector number from the BLKX header
(see http://newosxbook.com/DMG.html).
The implementation of dmg2img (from vu1tur) does not base the output
sector on the location of the terminator (0xffffffff) either so it
should be safe to drop this dependency on the previous state.
(It makes somehow makes sense, a terminator should halt further
processing of a block and is perhaps used to preallocate some space.)
Signed-off-by: Peter Wu <address@hidden>
Reviewed-by: John Snow <address@hidden>
Message-id: address@hidden
Signed-off-by: Stefan Hajnoczi <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
block/dmg.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)
diff --git a/block/dmg.c b/block/dmg.c
index 34dc632..d144a5e 100644
--- a/block/dmg.c
+++ b/block/dmg.c
@@ -187,7 +187,6 @@ typedef struct DmgHeaderState {
/* used internally by dmg_read_mish_block to remember offsets of blocks
* across calls */
uint64_t data_fork_offset;
- uint64_t last_out_offset;
/* exported for dmg_open */
uint32_t max_compressed_size;
uint32_t max_sectors_per_chunk;
@@ -203,6 +202,7 @@ static int dmg_read_mish_block(BDRVDMGState *s,
DmgHeaderState *ds,
int64_t offset = 0;
uint64_t data_offset;
uint64_t in_offset = ds->data_fork_offset;
+ uint64_t out_offset;
type = buff_read_uint32(buffer, offset);
/* skip data that is not a valid MISH block (invalid magic or too small) */
@@ -211,6 +211,9 @@ static int dmg_read_mish_block(BDRVDMGState *s,
DmgHeaderState *ds,
return 0;
}
+ /* chunk offsets are relative to this sector number */
+ out_offset = buff_read_uint64(buffer, offset + 8);
+
/* location in data fork for (compressed) blob (in bytes) */
data_offset = buff_read_uint64(buffer, offset + 0x18);
in_offset += data_offset;
@@ -231,10 +234,6 @@ static int dmg_read_mish_block(BDRVDMGState *s,
DmgHeaderState *ds,
offset += 4;
if (s->types[i] != 0x80000005 && s->types[i] != 1 &&
s->types[i] != 2) {
- if (s->types[i] == 0xffffffff && i > 0) {
- ds->last_out_offset = s->sectors[i - 1] +
- s->sectorcounts[i - 1];
- }
chunk_count--;
i--;
offset += 36;
@@ -243,7 +242,7 @@ static int dmg_read_mish_block(BDRVDMGState *s,
DmgHeaderState *ds,
offset += 4;
s->sectors[i] = buff_read_uint64(buffer, offset);
- s->sectors[i] += ds->last_out_offset;
+ s->sectors[i] += out_offset;
offset += 8;
s->sectorcounts[i] = buff_read_uint64(buffer, offset);
@@ -418,7 +417,6 @@ static int dmg_open(BlockDriverState *bs, QDict *options,
int flags,
s->offsets = s->lengths = s->sectors = s->sectorcounts = NULL;
/* used by dmg_read_mish_block to keep track of the current I/O position */
ds.data_fork_offset = 0;
- ds.last_out_offset = 0;
ds.max_compressed_size = 1;
ds.max_sectors_per_chunk = 1;
--
1.8.3.1
- [Qemu-devel] [PULL 16/42] virtio-blk: add a knob to disable request merging, (continued)
- [Qemu-devel] [PULL 16/42] virtio-blk: add a knob to disable request merging, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 22/42] block/dmg: extract processing of resource forks, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 25/42] block/dmg: process XML plists, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 19/42] block: add event when disk usage exceeds threshold, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 26/42] block/dmg: set virtual size to a non-zero value, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 21/42] block/dmg: extract mish block decoding functionality, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 29/42] block/dmg: factor out block type check, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 24/42] block/dmg: validate chunk size to avoid overflow, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 23/42] block/dmg: process a buffer instead of reading ints, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 27/42] block/dmg: fix sector data offset calculation, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 28/42] block/dmg: use SectorNumber from BLKX header,
Kevin Wolf <=
- [Qemu-devel] [PULL 31/42] block/dmg: improve zeroes handling, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 32/42] qed: check for header size overflow, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 34/42] block: fix off-by-one error in qcow and qcow2, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 37/42] iotests: Fix 104 for NBD, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 30/42] block/dmg: support bzip2 block entry types, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 33/42] qemu-iotests: add 116 invalid QED input file tests, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 38/42] nbd: Improve error messages, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 40/42] nbd: fix max_discard/max_transfer_length, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 35/42] iotests: Fix 083, Kevin Wolf, 2015/02/06
- [Qemu-devel] [PULL 36/42] iotests: Fix 100 for nbd, Kevin Wolf, 2015/02/06