[PATCH v2 04/13] md: prepare for managing resync I/O pages in clean way
STALE3501d
From: Ming Lei <tom.leiming@gmail.com>
Date: 2017-02-28 15:42:20
Also in:
linux-raid
Subsystem:
software raid (multiple disks) support, the rest · Maintainers:
Song Liu, Yu Kuai, Linus Torvalds
Revision v2 of 4 in this series.
Revisions (4)
- v1 [diff vs current]
- v1 [diff vs current]
- v2 current
- v3 [diff vs current]
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 <tom.leiming@gmail.com> --- drivers/md/md.h | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+)
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 1d63239a1be4..b5a638d85cb4 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h@@ -720,4 +720,58 @@ 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) + __free_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++) + __free_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) +{ + if (WARN_ON_ONCE(rp->idx >= RESYNC_PAGES)) + return NULL; + return rp->pages[rp->idx++]; +} + +static inline bool resync_page_available(struct resync_pages *rp) +{ + return rp->idx < RESYNC_PAGES; +} + #endif /* _MD_MD_H */
--
2.7.4