From 513e2faa0138462ce014e1b0e226ca45c83bc6c1 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 17 Mar 2017 00:12:24 +0800 Subject: [PATCH] md: prepare for managing resync I/O pages in clean way Now resync I/O use bio's bec table to manage pages, this way is very hacky, and may not work any more once multipage bvec is introduced. So introduce helpers and new data structure for managing resync I/O pages more cleanly. Signed-off-by: Ming Lei Signed-off-by: Shaohua Li --- drivers/md/md.h | 50 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/drivers/md/md.h b/drivers/md/md.h index 31d2d70849b6..0418b29945e7 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -723,4 +723,54 @@ static inline void mddev_check_writesame(struct mddev *mddev, struct bio *bio) #define RESYNC_BLOCK_SIZE (64*1024) #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE) +/* for managing resync I/O pages */ +struct resync_pages { + unsigned idx; /* for get/put page from the pool */ + void *raid_bio; + struct page *pages[RESYNC_PAGES]; +}; + +static inline int resync_alloc_pages(struct resync_pages *rp, + gfp_t gfp_flags) +{ + int i; + + for (i = 0; i < RESYNC_PAGES; i++) { + rp->pages[i] = alloc_page(gfp_flags); + if (!rp->pages[i]) + goto out_free; + } + + return 0; + +out_free: + while (--i >= 0) + put_page(rp->pages[i]); + return -ENOMEM; +} + +static inline void resync_free_pages(struct resync_pages *rp) +{ + int i; + + for (i = 0; i < RESYNC_PAGES; i++) + put_page(rp->pages[i]); +} + +static inline void resync_get_all_pages(struct resync_pages *rp) +{ + int i; + + for (i = 0; i < RESYNC_PAGES; i++) + get_page(rp->pages[i]); +} + +static inline struct page *resync_fetch_page(struct resync_pages *rp, + unsigned idx) +{ + if (WARN_ON_ONCE(idx >= RESYNC_PAGES)) + return NULL; + return rp->pages[idx]; +} + #endif /* _MD_MD_H */ -- 2.20.1