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parallels: Incorrect data end calculation in parallels_open() 

The BDRVParallelsState structure contains data_end field that is measured
in sectors. In parallels_open() initially this field is set by data_off
field from parallels image header.

According to the parallels format documentation, data_off field contains
an offset, in sectors, from the start of the file to the start of the
data area. For "WithoutFreeSpace" images: if data_off is zero, the offset
is calculated as the end of the BAT table plus some padding to ensure
sector size alignment.

The parallels_open() function has code for handling zero value in
data_off, but in the result data_end contains the offset in bytes.

Replace the alignment to sector size by division by sector size and fix
the comparision with s->header_size.

Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
This commit is contained in:
Alexander Ivanov 2023-07-18 12:44:24 +02:00 committed by Denis V. Lunev
parent a338dcbbab
commit fcadb48662
1 changed files with 2 additions and 2 deletions
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4
block/parallels.c
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@ -865,9 +865,9 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
}
s->data_end = le32_to_cpu(ph.data_off);
if (s->data_end == 0) {
s->data_end = ROUND_UP(bat_entry_off(s->bat_size), BDRV_SECTOR_SIZE);
s->data_end = DIV_ROUND_UP(size, BDRV_SECTOR_SIZE);
}
if (s->data_end < s->header_size) {
if (s->data_end < (s->header_size >> BDRV_SECTOR_BITS)) {
/*
* There is not enough unused space to fit to block align between BAT
* and actual data. We can't avoid read-modify-write...