On Thu, 12 Feb 2009 18:50:33 +0900 FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> wrote: > On Thu, 12 Feb 2009 11:19:09 +0200 > Boaz Harrosh <bharrosh@xxxxxxxxxxx> wrote: > > > Boaz Harrosh wrote: > > > /** > > > * blk_rq_map_pages - Receives an array of pages and appends them to a request structure > > > * > > > * @rq: The request to map > > > * @pages_info: A structure that specifies the array of pages, offset and more that need to be > > > * map to the request. the @pages_info->null_mapped is assumed to be 1 and is ignored. > > > * @length: Total bytes to map. Array of pages can be larger, stop mapping after @length bytes mapped. > > > * @max_pages: When allocating the internal bio use @max_pages as an hint that says the amount of anticipated > > > * pages that will be mapped. This member is optional and can be zero. > > > * > > > * blk_rq_map_pages can be called multiple times so the user does not need to allocate a contiguous array > > > * of struct page pointers but can call this routine multiple times. In that case max_pages can be set > > > * so no bio re-allocation occurs. > > > * There is no unmap function for this mapping, the request is completed in the regular way. > > > */ > > > > > > int blk_rq_map_pages(struct request rq, struct *rq_map_data pages_info, unsigned length, unsigned max_pages); > > > > > > > > > Implementation comments: > > > - Then when this member is available many places that call blk_rq_map_user() rq_map_data and null_mapped set, > > > and buff == NULL, can be converted to this member. > > > > > > - Internal block implementation is refactored to not duplicate any code with blk_rq_map_user(). > > > > > > Thanks for any comments > > > Boaz > > > > > > -- > > > > FUJITA Tomonori wrote: > > > Please send a patch to implement the proposal. > > > > > > > Is the above API accepted by you? Is it accepted by Jens? > > Should I also attempt first comment above. > > > > If its OK I will implement it ASAP. > > Sorry, I'm not sure until I see the actual code. You always find > tricky things when you actually write the code. > > The patch should be small. It's not difficult at all to write a patch > to see how it works. BTW, the idea is fine by me: I have some page frames and want to build a request out of them. That's what st and osst want. If OSD ULD wants it, adding a new API for it sounds a good idea to me. Then we can remove some features of blk_rq_map_user that I added for st and osst. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
