FUJITA Tomonori wrote: > 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. Right, I agree with you totally. I'm on it, I'll try an RFC see how it goes, and we can decide from there. Thanks TOMO Boaz -- 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
