On 26.05.23 23:41, David Howells wrote:
Provide a function to get an additional pin on a page that we already have a pin on. This will be used in fs/direct-io.c when dispatching multiple bios to a page we've extracted from a user-backed iter rather than redoing the extraction.
I guess this function is only used for "replicating" an existing pin, and not changing the semantics of an existing pin: something that was pinned !FOLL_LONGTERM cannot suddenly become effectively pinned FOLL_LONGTERM.
Out of curiosity, could we end up passing in an anonymous page, or is this almost exclusively for pagecache+zero pages? (I rememebr John H. had a similar patch where he said it would not apply to anon pages)
Signed-off-by: David Howells <dhowells@xxxxxxxxxx> cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> cc: David Hildenbrand <david@xxxxxxxxxx> cc: Lorenzo Stoakes <lstoakes@xxxxxxxxx> cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> cc: Jens Axboe <axboe@xxxxxxxxx> cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> cc: Jan Kara <jack@xxxxxxx> cc: Jeff Layton <jlayton@xxxxxxxxxx> cc: Jason Gunthorpe <jgg@xxxxxxxxxx> cc: Logan Gunthorpe <logang@xxxxxxxxxxxx> cc: Hillf Danton <hdanton@xxxxxxxx> cc: Christian Brauner <brauner@xxxxxxxxxx> cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> cc: linux-fsdevel@xxxxxxxxxxxxxxx cc: linux-block@xxxxxxxxxxxxxxx cc: linux-kernel@xxxxxxxxxxxxxxx cc: linux-mm@xxxxxxxxx ---
Acked-by: David Hildenbrand <david@xxxxxxxxxx> -- Thanks, David / dhildenb
