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Aivazian" , David Sterba , OGAWA Hirofumi , Muchun Song , Oscar Salvador , David Hildenbrand , linux-mm@kvack.org, linux-aio@kvack.org, Benjamin LaHaise Subject: Re: [PATCH 18/32] fs: Provide operation for fetching mapping_metadata_bhs Message-ID: References: <20260303101717.27224-1-jack@suse.cz> <20260303103406.4355-50-jack@suse.cz> <4ji4ihp7tzhxr35t2vgnswfskrjnsuo4eys4klblnor2b663pp@x3khuzh7cxhv> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4ji4ihp7tzhxr35t2vgnswfskrjnsuo4eys4klblnor2b663pp@x3khuzh7cxhv> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 99A2A20003 X-Stat-Signature: s1h3wt3h5g6ggz1dsqezs1tayjq1436m X-HE-Tag: 1772631856-948255 X-HE-Meta: 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 qIX9xK85 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Mar 04, 2026 at 02:38:41PM +0100, Jan Kara wrote: > I was looking into that. Passing these to sync_mapping_buffers(), > invalidate_inode_buffers() is easy. Passing to mark_buffer_dirty_inode() is > relatively tedious but doable. Where it gets difficult are calls like > bforget() and most importantly try_to_free_buffers() on bdev mapping where > you currently have no way to get to the mmb struct... We do have > b_assoc_map pointer in buffer_head which we could switch to point to mmb > instead but IO error handling on bhs needs to get to the mapping from bh so > we'd then have to add address_space pointer to mmb for these uses. All in > all it's doable but I've decided it isn't really worth it. I guess a backpointer from the bh list to the mapping/inode would solve all this? Or am I missing something?