linux-kernel - Re:Re: [f2fs-dev] [PATCH] f2fs: avoid f2fs_map_blocks() for consecutive holes in readpages

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Message-ID: <7489ce81.333.19bd8ca5df6.Coremail.nzzhao@126.com>
Date: Tue, 20 Jan 2026 08:24:59 +0800 (CST)
From: "Nanzhe Zhao" <nzzhao@....com>
To: "Chao Yu" <chao@...nel.org>
Cc: jaegeuk@...nel.org, linux-kernel@...r.kernel.org,
	linux-f2fs-devel@...ts.sourceforge.net
Subject: Re:Re: [f2fs-dev] [PATCH] f2fs: avoid f2fs_map_blocks() for
 consecutive holes in readpages

Hi Chao:
At 2026-01-19 21:44:48, "Chao Yu" <chao@...nel.org> wrote:
>
>I guess f2fs_map_no_dnode() will update map->m_next_pgofs to pgofs of next
>potential valid dnode.
>
>Thanks,
>

I guess we were discussing the cases that f2fs_get_dnode_of_data won't return
-ENOENT in f2fs_map_blocks but dn.blkaddr is still NULL_ADDR or NEW_ADDR ?

I think I might understand the intention behind your repeated emphasis on the 
f2fs_map_no_dnode case?  Are you saying that, on F2FS, the vast majority of sparse 
files fall into holes where the dnode hasn't been allocated at all, and that within the 
dnode the blkaddr values NULL_ADDR and NEW_ADDR—especially the latter on the read path
—are relatively uncommon?

Thanks,
Nanzhe Zhao