diff mbox series

[v7,11/15] btrfs: add send stream v2 definitions

Message ID ca550f6e2d6d1e7d79dee6c811638d4da02a56cc.1611346574.git.osandov@fb.com (mailing list archive)
State New
Headers show
Series None | expand

Commit Message

Omar Sandoval Jan. 22, 2021, 8:46 p.m. UTC
From: Omar Sandoval <osandov@fb.com>

This adds the definitions of the new commands for send stream version 2
and their respective attributes: fallocate, FS_IOC_SETFLAGS (a.k.a.
chattr), and encoded writes. It also documents two changes to the send
stream format in v2: the receiver shouldn't assume a maximum command
size, and the DATA attribute is encoded differently to allow for writes
larger than 64k. These will be implemented in subsequent changes, and
then the ioctl will accept the new flags.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 fs/btrfs/send.c            |  2 +-
 fs/btrfs/send.h            | 30 +++++++++++++++++++++++++++++-
 include/uapi/linux/btrfs.h | 13 +++++++++++++
 3 files changed, 43 insertions(+), 2 deletions(-)

Comments

Omar Sandoval Jan. 22, 2021, 8:57 p.m. UTC | #1
Please ignore 11-15. I fat fingered format-patch, these are part of the
other series.
diff mbox series

Patch

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 3bcbf2bcb869..d07570588a16 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -7267,7 +7267,7 @@  long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg)
 
 	sctx->clone_roots_cnt = arg->clone_sources_count;
 
-	sctx->send_max_size = BTRFS_SEND_BUF_SIZE;
+	sctx->send_max_size = BTRFS_SEND_BUF_SIZE_V1;
 	sctx->send_buf = kvmalloc(sctx->send_max_size, GFP_KERNEL);
 	if (!sctx->send_buf) {
 		ret = -ENOMEM;
diff --git a/fs/btrfs/send.h b/fs/btrfs/send.h
index de91488b7cd0..9f4f7b96b1eb 100644
--- a/fs/btrfs/send.h
+++ b/fs/btrfs/send.h
@@ -12,7 +12,11 @@ 
 #define BTRFS_SEND_STREAM_MAGIC "btrfs-stream"
 #define BTRFS_SEND_STREAM_VERSION 1
 
-#define BTRFS_SEND_BUF_SIZE SZ_64K
+/*
+ * In send stream v1, no command is larger than 64k. In send stream v2, no limit
+ * should be assumed.
+ */
+#define BTRFS_SEND_BUF_SIZE_V1 SZ_64K
 
 enum btrfs_tlv_type {
 	BTRFS_TLV_U8,
@@ -76,6 +80,13 @@  enum btrfs_send_cmd {
 
 	BTRFS_SEND_C_END,
 	BTRFS_SEND_C_UPDATE_EXTENT,
+
+	/* The following commands were added in send stream v2. */
+
+	BTRFS_SEND_C_FALLOCATE,
+	BTRFS_SEND_C_SETFLAGS,
+	BTRFS_SEND_C_ENCODED_WRITE,
+
 	__BTRFS_SEND_C_MAX,
 };
 #define BTRFS_SEND_C_MAX (__BTRFS_SEND_C_MAX - 1)
@@ -106,6 +117,11 @@  enum {
 	BTRFS_SEND_A_PATH_LINK,
 
 	BTRFS_SEND_A_FILE_OFFSET,
+	/*
+	 * In send stream v2, this attribute is special: it must be the last
+	 * attribute in a command, its header contains only the type, and its
+	 * length is implicitly the remaining length of the command.
+	 */
 	BTRFS_SEND_A_DATA,
 
 	BTRFS_SEND_A_CLONE_UUID,
@@ -114,6 +130,18 @@  enum {
 	BTRFS_SEND_A_CLONE_OFFSET,
 	BTRFS_SEND_A_CLONE_LEN,
 
+	/* The following attributes were added in send stream v2. */
+
+	BTRFS_SEND_A_FALLOCATE_MODE,
+
+	BTRFS_SEND_A_SETFLAGS_FLAGS,
+
+	BTRFS_SEND_A_UNENCODED_FILE_LEN,
+	BTRFS_SEND_A_UNENCODED_LEN,
+	BTRFS_SEND_A_UNENCODED_OFFSET,
+	BTRFS_SEND_A_COMPRESSION,
+	BTRFS_SEND_A_ENCRYPTION,
+
 	__BTRFS_SEND_A_MAX,
 };
 #define BTRFS_SEND_A_MAX (__BTRFS_SEND_A_MAX - 1)
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index 5df73001aad4..93aa0932234e 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -770,6 +770,19 @@  struct btrfs_ioctl_received_subvol_args {
  */
 #define BTRFS_SEND_FLAG_OMIT_END_CMD		0x4
 
+/*
+ * Use version 2 of the send stream, which adds new commands and supports larger
+ * writes.
+ */
+#define BTRFS_SEND_FLAG_STREAM_V2		0x8
+
+/*
+ * Send compressed data using the ENCODED_WRITE command instead of decompressing
+ * the data and sending it with the WRITE command. This requires
+ * BTRFS_SEND_FLAG_STREAM_V2.
+ */
+#define BTRFS_SEND_FLAG_COMPRESSED		0x10
+
 #define BTRFS_SEND_FLAG_MASK \
 	(BTRFS_SEND_FLAG_NO_FILE_DATA | \
 	 BTRFS_SEND_FLAG_OMIT_STREAM_HEADER | \