From 0cf1e9d6c34d4c82ac3af8015594849814843d36 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Fri, 29 Aug 2014 15:18:37 -0700 Subject: [PATCH] zram: fix incorrect stat with failed_reads Since we allocate a temporary buffer in zram_bvec_read to handle partial page operations in commit 924bd88d703e ("Staging: zram: allow partial page operations"), our ->failed_reads value may be incorrect as we do not increase its value when failing to allocate the temporary buffer. Let's fix this issue and correct the annotation of failed_reads. Signed-off-by: Chao Yu Acked-by: Minchan Kim Cc: Nitin Gupta Acked-by: Jerome Marchand Acked-by: Sergey Senozhatsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/zram/zram_drv.c | 10 +++++++--- drivers/block/zram/zram_drv.h | 2 +- 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index dfa4024c448a..d00831c3d731 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -378,7 +378,6 @@ static int zram_decompress_page(struct zram *zram, char *mem, u32 index) /* Should NEVER happen. Return bio error if it does. */ if (unlikely(ret)) { pr_err("Decompression failed! err=%d, page=%u\n", ret, index); - atomic64_inc(&zram->stats.failed_reads); return ret; } @@ -547,8 +546,6 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index, zcomp_strm_release(zram->comp, zstrm); if (is_partial_io(bvec)) kfree(uncmem); - if (ret) - atomic64_inc(&zram->stats.failed_writes); return ret; } @@ -566,6 +563,13 @@ static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index, ret = zram_bvec_write(zram, bvec, index, offset); } + if (unlikely(ret)) { + if (rw == READ) + atomic64_inc(&zram->stats.failed_reads); + else + atomic64_inc(&zram->stats.failed_writes); + } + return ret; } diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index 5b0afde729cd..e0f725c87cc6 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -84,7 +84,7 @@ struct zram_stats { atomic64_t compr_data_size; /* compressed size of pages stored */ atomic64_t num_reads; /* failed + successful */ atomic64_t num_writes; /* --do-- */ - atomic64_t failed_reads; /* should NEVER! happen */ + atomic64_t failed_reads; /* can happen when memory is too low */ atomic64_t failed_writes; /* can happen when memory is too low */ atomic64_t invalid_io; /* non-page-aligned I/O requests */ atomic64_t notify_free; /* no. of swap slot free notifications */