Re: [PATCH RFC 4/9] ext4: don't read the inode block in ext4_sync_inode_metadata()

[sashiko-bot@kernel.org]

> In nojournal mode ext4_sync_inode_metadata() looks up the inode table
> block with __ext4_get_inode_loc_noinmem() which reads it from disk, with
> readahead of the inode table on top, if it isn't cached. But a block
> that isn't in the buffer cache is neither dirty nor under writeback. So
> there's nothing to write or to wait for and reading it in is pointless.
> 
> It's also not something we can afford once inode eviction calls
> ->sync_inode_metadata() from reclaim. So look the block up with
> sb_find_get_block_nonatomic() instead.
> 
> Note that ext4_get_inode_loc_noio() isn't usable here. It uses the
> atomic lookup and that one gives up on a folio that is being migrated.
> That's fine for a best-effort fast commit snapshot but not for a data
> integrity sync.
> 
> Cc: stable@vger.kernel.org # v7.3
> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>

Sashiko has reviewed this patch and found no issues.

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Sashiko AI review · https://sashiko.dev/#/patchset/20261029-work-inode-metadata_writeback-v1-0-7d6c678a585d@kernel.org?part=4