Linux Btrfs filesystem development
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From: Sidong Yang <realwakka@gmail.com>
To: linux-btrfs <linux-btrfs@vger.kernel.org>
Cc: Sidong Yang <realwakka@gmail.com>
Subject: [PATCH] btrfs: reflink: Assure length != 0 in btrfs_extent_same()
Date: Wed, 18 Aug 2021 16:08:15 +0000	[thread overview]
Message-ID: <20210818160815.1820-1-realwakka@gmail.com> (raw)

btrfs_extent_same() cannot be called with zero length. Because when
length is zero, it would be filtered by condition in
btrfs_remap_file_range(). But if this function is used in other case in
future, it can make ret as uninitialized.

Signed-off-by: Sidong Yang <realwakka@gmail.com>
---
 fs/btrfs/reflink.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/btrfs/reflink.c b/fs/btrfs/reflink.c
index 9b0814318e72..69eb50f2f0b4 100644
--- a/fs/btrfs/reflink.c
+++ b/fs/btrfs/reflink.c
@@ -653,6 +653,7 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
 	u64 i, tail_len, chunk_count;
 	struct btrfs_root *root_dst = BTRFS_I(dst)->root;
 
+	ASSERT(olen);
 	spin_lock(&root_dst->root_item_lock);
 	if (root_dst->send_in_progress) {
 		btrfs_warn_rl(root_dst->fs_info,
-- 
2.25.1


             reply	other threads:[~2021-08-18 16:08 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-18 16:08 Sidong Yang [this message]
2021-08-18 22:24 ` [PATCH] btrfs: reflink: Assure length != 0 in btrfs_extent_same() David Sterba
2021-08-18 23:22   ` Sidong Yang
2021-08-19  8:04 ` Nikolay Borisov
2021-08-19 15:32   ` Sidong Yang
2021-08-19 18:12     ` David Sterba
2021-08-20  0:32       ` Sidong Yang

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