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From:   Daeho Jeong <daeho43@gmail.com>
To:     linux-kernel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net, kernel-team@android.com
Cc:     Daeho Jeong <daehojeong@google.com>
Subject: [PATCH] f2fs: ignore when len of range in f2fs_sec_trim_file is zero
Date:   Thu,  9 Jul 2020 10:57:39 +0900
Message-Id: <20200709015739.1653668-1-daeho43@gmail.com>
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From: Daeho Jeong <daehojeong@google.com>

When end_addr comes to zero, it'll trigger different behaviour.
To prevent this, we need to ignore the case of that range.len is
zero in the function.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
---
 fs/f2fs/file.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 368c80f8e2a1..98b0a8dbf669 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3813,15 +3813,14 @@ static int f2fs_sec_trim_file(struct file *filp, unsigned long arg)
 	file_start_write(filp);
 	inode_lock(inode);
 
-	if (f2fs_is_atomic_file(inode) || f2fs_compressed_file(inode)) {
+	if (f2fs_is_atomic_file(inode) || f2fs_compressed_file(inode) ||
+			range.start >= inode->i_size) {
 		ret = -EINVAL;
 		goto err;
 	}
 
-	if (range.start >= inode->i_size) {
-		ret = -EINVAL;
+	if (range.len == 0)
 		goto err;
-	}
 
 	if (inode->i_size - range.start < range.len) {
 		ret = -E2BIG;
-- 
2.27.0.383.g050319c2ae-goog