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 <chao2.yu@samsung.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 @@
/* 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 @@
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 @@
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 @@
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 */