[Devel] [PATCH hci-8.1 v6 3/6] dm-qcow2: extend the file in place_r2() before linking the refblock

[no-reply at sashiko.virtuozzo.com]

> place_r2() links a new refblock into R1, but moves neither file_size
> nor file_preallocated_area_start. The refblock stays at or above the
> watermark if truncate_prealloc_safe() in allocate_cluster() fails
> after place_r2(), or if a parallel mark_cluster_unused() lowers
> free_cluster_search_pos before the second pass of
> find_unused_cluster(). Truncation of preallocations on suspend then
> cuts the file under the refblock: R1 on disk points past EOF, and
> the next session gets -EIO on allocations in the range it covers.
> 
> Extend the file and raise the watermark to the end of the refblock
> before linking it into R1, as allocate_cluster() does for data
> clusters.
> 
> https://virtuozzo.atlassian.net/browse/VSTOR-148171
> Feature: dm-qcow2: block device over QCOW2 files driver
> 
> Signed-off-by: Alexander Ivanov <alexander.ivanov at virtuozzo.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.vzint.dev/#/patchset/20261022121706.1890593-1-alexander.ivanov@virtuozzo.com?part=3