ext4: support large block size in ext4_mb_load_buddy_gfp()

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Currently, ext4_mb_load_buddy_gfp() uses blocks_per_page to calculate the
folio index and offset. However, when blocksize is larger than PAGE_SIZE,
blocks_per_page becomes zero, leading to a potential division-by-zero bug.

To support BS > PS, use bytes to compute folio index and offset within
folio to get rid of blocks_per_page.

Also, if buddy and bitmap land in the same folio, we get that folio’s ref
instead of looking it up again before updating the buddy.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Message-ID: <20251121090654.631996-12-libaokun@huaweicloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

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Baokun Li 2025-11-21 17:06:41 +08:00 • committed by Theodore Ts'o

parent 2a8de76b2b

commit 6117f1806a

1 changed files with 16 additions and 11 deletions

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fs/ext4/mballoc.c

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