Re: [PATCH v9 01/14] xfs: don't skip the flush before shifting extents

[sashiko-bot@kernel.org]

> On an XFS file larger than 4 EiB, collapse range and insert range can
> drop dirty data without writing it back, and then fail with
> EFSCORRUPTED.
> 
> xfs_prepare_shift() flushes the page cache from its offset to EOF, but
> passes i_size as the length. Above 4 EiB the end of that range can
> overflow and turn negative. filemap_write_and_wait_range() then writes
> nothing, but truncate_pagecache_range() takes the end as unsigned and
> drops every folio from the start of the range onward.
> 
> A delalloc extent under a dropped folio stays in the data fork, and the
> shift returns -EFSCORRUPTED for it.
> 
> The fix used here is to pass i_size - offset as the length.
> 
> Fixes: 7f9f71be84bc ("xfs: extent shifting doesn't fully invalidate page cache")
> Fixes: feeb9b269523 ("filemap: skip write and wait if end offset precedes start")
> Signed-off-by: Chris Mason <mason@kernel.org>

Sashiko has reviewed this patch and found no issues.

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Sashiko AI review · https://sashiko.dev/#/patchset/20261112214604.67875-1-mason@kernel.org?part=1