On 08/13/2014 04:01 AM, Chao Yu wrote:
> Since we allocate a temporary buffer in zram_bvec_read to handle partial page
> operations in this commit 924bd88d703e53d30f393fac6117f8f1bc79aab6 (Staging:
> zram: allow partial page operations), our ->failed_reads value may be
> incorrect
> as we do not increase its value when failed to allocate the temporary buffer.
>
> Let's fix this issue and correct the annotation of failed_reads.
>
> v2: clean codes of failed_{reads,writes} stat pointed out by Minchan Kim, and
> this cleanup also fix incorrectly stat when fail in zram_decompress_page.
>
> Signed-off-by: Chao Yu <[email protected]>Acked-by: Jerome Marchand <[email protected]> > --- > 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 dfa4024..d00831c 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 @@ out: > 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 5b0afde..e0f725c 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 */ >
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