In NVS, allocation table entries (ATEs) are written backwards within
each sector. Under delete-only or delete-heavy workloads, a sector may
contain only delete ATEs, causing the ATE write pointer to approach the
sector boundary.
Without an explicit boundary check, ATE writes may occur at offset 0 of
the current sector, allowing the write pointer to underflow into the
previous sector and corrupt unrelated data or metadata.
Fix this by disallowing ATE writes when the write pointer is at the
sector boundary. This ensures that ATE writes remain confined to the
current sector and prevents pointer underflow across sectors.
Signed-off-by: Lingao Meng <menglingao@xiaomi.com>
d845a2230e