linux-kernel - [PATCH 2/2] xfs: remove the extra processing of zero size in xfs_idata

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Date:   Tue, 24 Nov 2020 18:45:31 +0800
From:   Zhen Lei <thunder.leizhen@...wei.com>
To:     "Darrick J . Wong" <darrick.wong@...cle.com>,
        Brian Foster <bfoster@...hat.com>,
        linux-xfs <linux-xfs@...r.kernel.org>,
        linux-kernel <linux-kernel@...r.kernel.org>
CC:     Zhen Lei <thunder.leizhen@...wei.com>
Subject: [PATCH 2/2] xfs: remove the extra processing of zero size in xfs_idata_realloc()

krealloc() does the free operation when the parameter new_size is 0, with
ZERO_SIZE_PTR returned. Because all other places use NULL to check whether
if_data is available or not, so covert it from ZERO_SIZE_PTR to NULL.

Signed-off-by: Zhen Lei <thunder.leizhen@...wei.com>
---
 fs/xfs/libxfs/xfs_inode_fork.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c
index 4e457aea8493..518af4088e79 100644
--- a/fs/xfs/libxfs/xfs_inode_fork.c
+++ b/fs/xfs/libxfs/xfs_inode_fork.c
@@ -492,13 +492,6 @@ xfs_idata_realloc(
 	if (byte_diff == 0)
 		return;
 
-	if (new_size == 0) {
-		kmem_free(ifp->if_u1.if_data);
-		ifp->if_u1.if_data = NULL;
-		ifp->if_bytes = 0;
-		return;
-	}
-
 	/*
 	 * For inline data, the underlying buffer must be a multiple of 4 bytes
 	 * in size so that it can be logged and stay on word boundaries.
@@ -510,7 +503,7 @@ xfs_idata_realloc(
 		WARN(1, "if_data realloc failed\n");
 		return;
 	}
-	ifp->if_u1.if_data = if_data;
+	ifp->if_u1.if_data = ZERO_OR_NULL_PTR(if_data) ? NULL : if_data;
 	ifp->if_bytes = new_size;
 }
 
-- 
2.26.0.106.g9fadedd