From:   Qu Wenruo <wqu@suse.com>
To:     linux-btrfs@vger.kernel.org
Cc:     Su Yue <suy.fnst@cn.fujitsu.com>
Subject: [PATCH 02/13] btrfs-progs: lowmem: add argument path to punch_extent_hole()
Date:   Tue, 18 Dec 2018 18:46:35 +0800
Message-Id: <20181218104646.29599-3-wqu@suse.com>
In-Reply-To: <20181218104646.29599-1-wqu@suse.com>
References: <20181218104646.29599-1-wqu@suse.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-btrfs-owner@vger.kernel.org
Precedence: bulk

From: Su Yue <suy.fnst@cn.fujitsu.com>

Since repair will do CoW, the outer path may be invalid.

This patch will add an argument, @path, to punch_extent_hole().
When punch_extent_hole() returns, path will still point to the same key.

Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
[Update comment and commit message]
Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 check/mode-lowmem.c | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c
index ac2e4481435f..0f8af35d4da1 100644
--- a/check/mode-lowmem.c
+++ b/check/mode-lowmem.c
@@ -1755,28 +1755,37 @@ out:
 /*
  * Wrapper function of btrfs_punch_hole.
  *
+ * @path:	The path holder, will point to the same key after hole punching.
+ *
  * Returns 0 means success.
  * Returns not 0 means error.
  */
-static int punch_extent_hole(struct btrfs_root *root, u64 ino, u64 start,
-			     u64 len)
+static int punch_extent_hole(struct btrfs_root *root, struct btrfs_path *path,
+			     u64 ino, u64 start, u64 len)
 {
 	struct btrfs_trans_handle *trans;
-	int ret = 0;
+	struct btrfs_key key;
+	int ret;
 
+	btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
 	trans = btrfs_start_transaction(root, 1);
 	if (IS_ERR(trans))
 		return PTR_ERR(trans);
 
 	ret = btrfs_punch_hole(trans, root, ino, start, len);
-	if (ret)
+	if (ret) {
 		error("failed to add hole [%llu, %llu] in inode [%llu]",
 		      start, len, ino);
-	else
-		printf("Add a hole [%llu, %llu] in inode [%llu]\n", start, len,
-		       ino);
-
+		btrfs_abort_transaction(trans, ret);
+		return ret;
+	}
+	printf("Add a hole [%llu, %llu] in inode [%llu]\n", start, len, ino);
 	btrfs_commit_transaction(trans, root);
+
+	btrfs_release_path(path);
+	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+	if (ret > 0)
+		ret = -ENOENT;
 	return ret;
 }
 
@@ -2027,7 +2036,7 @@ static int check_file_extent(struct btrfs_root *root, struct btrfs_path *path,
 	/* Check EXTENT_DATA hole */
 	if (!no_holes && *end != fkey.offset) {
 		if (repair)
-			ret = punch_extent_hole(root, fkey.objectid,
+			ret = punch_extent_hole(root, path, fkey.objectid,
 						*end, fkey.offset - *end);
 		if (!repair || ret) {
 			err |= FILE_EXTENT_ERROR;
@@ -2598,7 +2607,7 @@ out:
 
 		if (!nbytes && !no_holes && extent_end < isize) {
 			if (repair)
-				ret = punch_extent_hole(root, inode_id,
+				ret = punch_extent_hole(root, path, inode_id,
 						extent_end, isize - extent_end);
 			if (!repair || ret) {
 				err |= NBYTES_ERROR;
-- 
2.20.0