linux-kernel - [PATCH] pstore: Remove duplicate invoking of persistent_ram

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Message-ID: <20181025131645.8489-1-wangpeng15@xiaomi.com>
Date:   Thu, 25 Oct 2018 21:16:45 +0800
From:   Peng Wang <wangpeng15@...omi.com>
To:     <linux-kernel@...r.kernel.org>
CC:     Peng Wang <wangpeng15@...omi.com>
Subject: [PATCH] pstore: Remove duplicate invoking of persistent_ram_zap()

When initialing przs with invalid data in buffer(no PERSISTENT_RAM_SIG),
function call path is like this:

ramoops_init_prz ->
|
|-> persistent_ram_new -> persistent_ram_post_init -> persistent_ram_zap
|
|--> persistent_ram_zap

As we can see, persistent_ram_zap() is called twice.
We can avoid this by removing it in ramoops_init_prz(),
and only call it in persistent_ram_post_init().

Signed-off-by: Peng Wang <wangpeng15@...omi.com>
---
 fs/pstore/ram.c      | 2 --
 fs/pstore/ram_core.c | 3 +--
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index f4fd2e7..d2a3932 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -639,8 +639,6 @@ static int ramoops_init_prz(const char *name,
 		return err;
 	}
 
-	persistent_ram_zap(*prz);
-
 	*paddr += sz;
 
 	return 0;
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index 0792595..3ab4f34 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -504,15 +504,14 @@ static int persistent_ram_post_init(struct persistent_ram_zone *prz, u32 sig,
 			pr_debug("found existing buffer, size %zu, start %zu\n",
 				 buffer_size(prz), buffer_start(prz));
 			persistent_ram_save_old(prz);
-			return 0;
 		}
 	} else {
 		pr_debug("no valid data in buffer (sig = 0x%08x)\n",
 			 prz->buffer->sig);
+		prz->buffer->sig = sig;
 	}
 
 	/* Rewind missing or invalid memory area. */
-	prz->buffer->sig = sig;
 	persistent_ram_zap(prz);
 
 	return 0;
-- 
1.9.1