diff options
| author | Minchan Kim <minchan@kernel.org> | 2017-09-06 16:20:00 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-06 17:27:25 -0700 |
| commit | ae85a8075c5b025b9d503554ddc480a346a24536 (patch) | |
| tree | 633d5dda845b81d541008af1633412af06242deb /drivers/block/zram | |
| parent | 1363d4662a0d28dfdb81ef426c88c9a8dbf7c338 (diff) | |
| download | linux-ae85a8075c5b025b9d503554ddc480a346a24536.tar.bz2 | |
zram: identify asynchronous IO's return value
For upcoming asynchronous IO like writeback, zram_rw_page should be
aware of that whether requested IO was completed or submitted
successfully, otherwise error.
For the goal, zram_bvec_rw has three return values.
-errno: returns error number
0: IO request is done synchronously
1: IO request is issued successfully.
Link: http://lkml.kernel.org/r/1498459987-24562-7-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Juneho Choi <juno.choi@lge.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/block/zram')
| -rw-r--r-- | drivers/block/zram/zram_drv.c | 32 |
1 files changed, 24 insertions, 8 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index fcdbbb1e7745..8975f75f113d 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -772,7 +772,7 @@ out: static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index) { - int ret; + int ret = 0; unsigned long alloced_pages; unsigned long handle = 0; unsigned int comp_len = 0; @@ -877,7 +877,7 @@ out: /* Update stats */ atomic64_inc(&zram->stats.pages_stored); - return 0; + return ret; } static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, @@ -959,6 +959,11 @@ static void zram_bio_discard(struct zram *zram, u32 index, } } +/* + * Returns errno if it has some problem. Otherwise return 0 or 1. + * Returns 0 if IO request was done synchronously + * Returns 1 if IO request was successfully submitted. + */ static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index, int offset, bool is_write) { @@ -980,7 +985,7 @@ static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index, generic_end_io_acct(rw_acct, &zram->disk->part0, start_time); - if (unlikely(ret)) { + if (unlikely(ret < 0)) { if (!is_write) atomic64_inc(&zram->stats.failed_reads); else @@ -1073,7 +1078,7 @@ static void zram_slot_free_notify(struct block_device *bdev, static int zram_rw_page(struct block_device *bdev, sector_t sector, struct page *page, bool is_write) { - int offset, err = -EIO; + int offset, ret; u32 index; struct zram *zram; struct bio_vec bv; @@ -1082,7 +1087,7 @@ static int zram_rw_page(struct block_device *bdev, sector_t sector, if (!valid_io_request(zram, sector, PAGE_SIZE)) { atomic64_inc(&zram->stats.invalid_io); - err = -EINVAL; + ret = -EINVAL; goto out; } @@ -1093,7 +1098,7 @@ static int zram_rw_page(struct block_device *bdev, sector_t sector, bv.bv_len = PAGE_SIZE; bv.bv_offset = 0; - err = zram_bvec_rw(zram, &bv, index, offset, is_write); + ret = zram_bvec_rw(zram, &bv, index, offset, is_write); out: /* * If I/O fails, just return error(ie, non-zero) without @@ -1103,9 +1108,20 @@ out: * bio->bi_end_io does things to handle the error * (e.g., SetPageError, set_page_dirty and extra works). */ - if (err == 0) + if (unlikely(ret < 0)) + return ret; + + switch (ret) { + case 0: page_endio(page, is_write, 0); - return err; + break; + case 1: + ret = 0; + break; + default: + WARN_ON(1); + } + return ret; } static void zram_reset_device(struct zram *zram) |