[037/272] staging: zram: fix data corruption issue

Greg KH
2011-02-16T01:48:02Z

From: Nitin Gupta <ngupta@vflare.org>

commit 5414e557fca545614ceedc3d3496f747457e2e3b upstream.

In zram_read() and zram_write() we were not incrementing the
index number and thus were reading/writing values from/to
incorrect sectors on zram disk, resulting in data corruption.

Signed-off-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/staging/zram/zram_drv.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/staging/zram/zram_drv.c
+++ b/drivers/staging/zram/zram_drv.c
@@ -227,6 +227,7 @@ static int zram_read(struct zram *zram,

if (zram_test_flag(zram, index, ZRAM_ZERO)) {
handle_zero_page(page);
+ index++;
continue;
}

@@ -235,12 +236,14 @@ static int zram_read(struct zram *zram,
pr_debug("Read before write: sector=%lu, size=%u",
(ulong)(bio->bi_sector), bio->bi_size);
/* Do nothing */
+ index++;
continue;
}

/* Page is stored uncompressed since it's incompressible */
if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) {
handle_uncompressed_page(zram, page, index);
+ index++;
continue;
}

@@ -320,6 +323,7 @@ static int zram_write(struct zram *zram,
mutex_unlock(&zram->lock);
zram_stat_inc(&zram->stats.pages_zero);
zram_set_flag(zram, index, ZRAM_ZERO);
+ index++;
continue;
}