[PATCH v2 27/36] btrfs: explicitly track file extent length for replace and drop

[Josef Bacik <josef@toxicpanda.com>]

From: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>

With the advent of storing fscrypt contexts with each encrypted extent,
extents will have a variable length depending on encryption status.
Make sure the replace and drop file extent item helpers encode this
information so that everything gets updated properly.

Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/ctree.h    | 2 ++
 fs/btrfs/file.c     | 4 ++--
 fs/btrfs/inode.c    | 7 +++++--
 fs/btrfs/reflink.c  | 1 +
 fs/btrfs/tree-log.c | 5 +++--
 5 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index c8f1d2d7c46c..e5879bd7f2f7 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -372,6 +372,8 @@ struct btrfs_replace_extent_info {
 	u64 file_offset;
 	/* Pointer to a file extent item of type regular or prealloc. */
 	char *extent_buf;
+	/* The length of @extent_buf */
+	u32 extent_buf_size;
 	/*
 	 * Set to true when attempting to replace a file range with a new extent
 	 * described by this structure, set to false when attempting to clone an
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 26905b77c7e8..a19ac854e07f 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2261,14 +2261,14 @@ static int btrfs_insert_replace_extent(struct btrfs_trans_handle *trans,
 	key.type = BTRFS_EXTENT_DATA_KEY;
 	key.offset = extent_info->file_offset;
 	ret = btrfs_insert_empty_item(trans, root, path, &key,
-				      sizeof(struct btrfs_file_extent_item));
+				      extent_info->extent_buf_size);
 	if (ret)
 		return ret;
 	leaf = path->nodes[0];
 	slot = path->slots[0];
 	write_extent_buffer(leaf, extent_info->extent_buf,
 			    btrfs_item_ptr_offset(leaf, slot),
-			    sizeof(struct btrfs_file_extent_item));
+			    extent_info->extent_buf_size);
 	extent = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
 	ASSERT(btrfs_file_extent_type(leaf, extent) != BTRFS_FILE_EXTENT_INLINE);
 	btrfs_set_file_extent_offset(leaf, extent, extent_info->data_offset);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index d20ccfc5038f..03bc9f41bd33 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2898,6 +2898,7 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
 	u64 num_bytes = btrfs_stack_file_extent_num_bytes(stack_fi);
 	u64 ram_bytes = btrfs_stack_file_extent_ram_bytes(stack_fi);
 	struct btrfs_drop_extents_args drop_args = { 0 };
+	size_t fscrypt_context_size = 0;
 	int ret;
 
 	path = btrfs_alloc_path();
@@ -2917,7 +2918,7 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
 	drop_args.start = file_pos;
 	drop_args.end = file_pos + num_bytes;
 	drop_args.replace_extent = true;
-	drop_args.extent_item_size = sizeof(*stack_fi);
+	drop_args.extent_item_size = sizeof(*stack_fi) + fscrypt_context_size;
 	ret = btrfs_drop_extents(trans, root, inode, &drop_args);
 	if (ret)
 		goto out;
@@ -2928,7 +2929,7 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
 		ins.type = BTRFS_EXTENT_DATA_KEY;
 
 		ret = btrfs_insert_empty_item(trans, root, path, &ins,
-					      sizeof(*stack_fi));
+					      sizeof(*stack_fi) + fscrypt_context_size);
 		if (ret)
 			goto out;
 	}
@@ -9671,6 +9672,7 @@ static struct btrfs_trans_handle *insert_prealloc_file_extent(
 	u64 len = ins->offset;
 	int qgroup_released;
 	int ret;
+	size_t fscrypt_context_size = 0;
 
 	memset(&stack_fi, 0, sizeof(stack_fi));
 
@@ -9703,6 +9705,7 @@ static struct btrfs_trans_handle *insert_prealloc_file_extent(
 	extent_info.data_len = len;
 	extent_info.file_offset = file_offset;
 	extent_info.extent_buf = (char *)&stack_fi;
+	extent_info.extent_buf_size = sizeof(stack_fi) + fscrypt_context_size;
 	extent_info.is_new_extent = true;
 	extent_info.update_times = true;
 	extent_info.qgroup_reserved = qgroup_released;
diff --git a/fs/btrfs/reflink.c b/fs/btrfs/reflink.c
index 3c66630d87ee..f5440ae447a4 100644
--- a/fs/btrfs/reflink.c
+++ b/fs/btrfs/reflink.c
@@ -500,6 +500,7 @@ static int btrfs_clone(struct inode *src, struct inode *inode,
 			clone_info.data_len = datal;
 			clone_info.file_offset = new_key.offset;
 			clone_info.extent_buf = buf;
+			clone_info.extent_buf_size = size;
 			clone_info.is_new_extent = false;
 			clone_info.update_times = !no_time_update;
 			ret = btrfs_replace_file_extents(BTRFS_I(inode), path,
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 404577383513..6cdb924944d1 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -4628,6 +4628,7 @@ static int log_one_extent(struct btrfs_trans_handle *trans,
 	u64 extent_offset = em->start - em->orig_start;
 	u64 block_len;
 	int ret;
+	size_t fscrypt_context_size = 0;
 	u8 encryption = BTRFS_ENCRYPTION_NONE;
 
 	btrfs_set_stack_file_extent_generation(&fi, trans->transid);
@@ -4670,7 +4671,7 @@ static int log_one_extent(struct btrfs_trans_handle *trans,
 		drop_args.start = em->start;
 		drop_args.end = em->start + em->len;
 		drop_args.replace_extent = true;
-		drop_args.extent_item_size = sizeof(fi);
+		drop_args.extent_item_size = sizeof(fi) + fscrypt_context_size;
 		ret = btrfs_drop_extents(trans, log, inode, &drop_args);
 		if (ret)
 			return ret;
@@ -4682,7 +4683,7 @@ static int log_one_extent(struct btrfs_trans_handle *trans,
 		key.offset = em->start;
 
 		ret = btrfs_insert_empty_item(trans, log, path, &key,
-					      sizeof(fi));
+					      sizeof(fi) + fscrypt_context_size);
 		if (ret)
 			return ret;
 	}
-- 
2.41.0