diff mbox series

[v1,16/17] btrfs: explicitly track file extent length and encryption

Message ID 31f44df875657de3e657fa7150408b222f72419d.1687988380.git.sweettea-kernel@dorminy.me (mailing list archive)
State New, archived
Headers show
Series btrfs: add encryption feature | expand

Commit Message

Sweet Tea Dorminy June 29, 2023, 12:35 a.m. UTC
With the advent of storing fscrypt contexts with each encrypted extent,
extents will have a variable length depending on encryption status.
Add accessors for the encryption field, and update all the checks for
file extents.

Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
---
 fs/btrfs/ctree.h                | 2 ++
 fs/btrfs/file.c                 | 4 ++--
 fs/btrfs/inode.c                | 9 +++++++--
 fs/btrfs/reflink.c              | 1 +
 fs/btrfs/tree-log.c             | 2 +-
 include/uapi/linux/btrfs_tree.h | 5 +++++
 6 files changed, 18 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index f2d2b313bde5..b1afcfc62f75 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -364,6 +364,8 @@  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 0de95c8375a1..703033816876 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2250,14 +2250,14 @@  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 931f948b42f7..2f709874124d 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3036,6 +3036,9 @@  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 =
+		btrfs_stack_file_extent_encryption(stack_fi) ?
+			FSCRYPT_SET_CONTEXT_MAX_SIZE : 0;
 	int ret;
 
 	path = btrfs_alloc_path();
@@ -3055,7 +3058,7 @@  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;
@@ -3066,7 +3069,7 @@  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;
 	}
@@ -9746,6 +9749,7 @@  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));
 
@@ -9778,6 +9782,7 @@  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 ad722f495c9b..9f3b5748f39b 100644
--- a/fs/btrfs/reflink.c
+++ b/fs/btrfs/reflink.c
@@ -502,6 +502,7 @@  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 5a636a6b0d82..eaf014ab7cac 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -4689,7 +4689,7 @@  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;
 	}
diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h
index ea88dd69957f..e780eee85e6e 100644
--- a/include/uapi/linux/btrfs_tree.h
+++ b/include/uapi/linux/btrfs_tree.h
@@ -1048,6 +1048,11 @@  struct btrfs_file_extent_item {
 	 * but not for stat.
 	 */
 	__u8 compression;
+
+	/*
+	 * 2 bits of encryption type in the lower bits, 6 bits of context size
+	 * in the upper bits. Unencrypted value is 0.
+	 */
 	__u8 encryption;
 	__le16 other_encoding; /* spare for later use */