From: Boris Burkov <borisb@xxxxxx>
Add a new btrfs_send_op and support for both dumping and proper receive
processing which does actual encoded writes.
Encoded writes are only allowed on a file descriptor opened with an extra
flag that allows encoded writes, so we also add support for this flag
when opening or reusing a file for writing.
Signed-off-by: Boris Burkov <boris@xxxxxx>
---
cmds/receive-dump.c | 16 +++++++-
cmds/receive.c | 98 +++++++++++++++++++++++++++++++++++++++++---
common/send-stream.c | 22 ++++++++++
common/send-stream.h | 4 ++
stubs.h | 39 ++++++++++++++++++
5 files changed, 173 insertions(+), 6 deletions(-)
diff --git a/cmds/receive-dump.c b/cmds/receive-dump.c
index 648d9314..20ec2b70 100644
--- a/cmds/receive-dump.c
+++ b/cmds/receive-dump.c
@@ -316,6 +316,19 @@ static int print_update_extent(const char *path, u64 offset, u64 len,
offset, len);
}
+static int print_encoded_write(const char *path, const void *data, u64 offset,
+ u64 len, u64 unencoded_file_len,
+ u64 unencoded_len, u64 unencoded_offset,
+ u32 compression, u32 encryption, void *user)
+{
+ return PRINT_DUMP(user, path, "encoded_write",
+ "offset=%llu len=%llu, unencoded_file_len=%llu, "
+ "unencoded_len=%llu, unencoded_offset=%llu, "
+ "compression=%u, encryption=%u",
+ offset, len, unencoded_file_len, unencoded_len,
+ unencoded_offset, compression, encryption);
+}
+
struct btrfs_send_ops btrfs_print_send_ops = {
.subvol = print_subvol,
.snapshot = print_snapshot,
@@ -337,5 +350,6 @@ struct btrfs_send_ops btrfs_print_send_ops = {
.chmod = print_chmod,
.chown = print_chown,
.utimes = print_utimes,
- .update_extent = print_update_extent
+ .update_extent = print_update_extent,
+ .encoded_write = print_encoded_write,
};
diff --git a/cmds/receive.c b/cmds/receive.c
index 2aaba3ff..cd0f47ec 100644
--- a/cmds/receive.c
+++ b/cmds/receive.c
@@ -30,12 +30,14 @@
#include <assert.h>
#include <getopt.h>
#include <limits.h>
+#include <errno.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>
+#include <sys/uio.h>
#include <sys/xattr.h>
#include <uuid/uuid.h>
@@ -52,6 +54,7 @@
#include "cmds/receive-dump.h"
#include "common/help.h"
#include "common/path-utils.h"
+#include "stubs.h"
struct btrfs_receive
{
@@ -60,6 +63,7 @@ struct btrfs_receive
int write_fd;
char write_path[PATH_MAX];
+ int write_fd_allow_encoded;
char *root_path;
char *dest_dir_path; /* relative to root_path */
@@ -643,24 +647,65 @@ out:
return ret;
}
-static int open_inode_for_write(struct btrfs_receive *rctx, const char *path)
+static int set_write_fd_allow_encoded(struct btrfs_receive *rctx)
+{
+ int ret;
+ int flags;
+
+ flags = fcntl(rctx->write_fd, F_GETFL);
+ if (flags < 0) {
+ ret = -errno;
+ error("failed to fetch old fd flags");
+ goto close_fd;
+ }
+ ret = fcntl(rctx->write_fd, F_SETFL, flags | O_ALLOW_ENCODED);
+ if (ret < 0) {
+ ret = -errno;
+ error("failed to enable encoded writes");
+ goto close_fd;
+ }
+ rctx->write_fd_allow_encoded = true;
+ ret = 0;
+ goto out;
+close_fd:
+ close(rctx->write_fd);
+ rctx->write_fd = -1;
+ rctx->write_fd_allow_encoded = false;
+out:
+ return ret;
+}
+
+static int open_inode_for_write(struct btrfs_receive *rctx, const char *path,
+ bool allow_encoded)
{
int ret = 0;
+ int flags = O_RDWR;
if (rctx->write_fd != -1) {
- if (strcmp(rctx->write_path, path) == 0)
+ /*
+ * if the existing fd is for this path and the needed flags are
+ * satisfied, no need to open a new one
+ */
+ if (strcmp(rctx->write_path, path) == 0) {
+ /* fixup the allow encoded flag, if necessary */
+ if (allow_encoded && !rctx->write_fd_allow_encoded)
+ ret = set_write_fd_allow_encoded(rctx);
goto out;
+ }
close(rctx->write_fd);
rctx->write_fd = -1;
}
- rctx->write_fd = open(path, O_RDWR);
+ if (allow_encoded)
+ flags |= O_ALLOW_ENCODED;
+ rctx->write_fd = open(path, flags);
if (rctx->write_fd < 0) {
ret = -errno;
error("cannot open %s: %m", path);
goto out;
}
strncpy_null(rctx->write_path, path);
+ rctx->write_fd_allow_encoded = allow_encoded;
out:
return ret;
@@ -691,7 +736,7 @@ static int process_write(const char *path, const void *data, u64 offset,
goto out;
}
- ret = open_inode_for_write(rctx, full_path);
+ ret = open_inode_for_write(rctx, full_path, false);
if (ret < 0)
goto out;
@@ -734,7 +779,7 @@ static int process_clone(const char *path, u64 offset, u64 len,
goto out;
}
- ret = open_inode_for_write(rctx, full_path);
+ ret = open_inode_for_write(rctx, full_path, false);
if (ret < 0)
goto out;
@@ -1028,6 +1073,48 @@ static int process_update_extent(const char *path, u64 offset, u64 len,
return 0;
}
+static int process_encoded_write(const char *path, const void *data, u64 offset,
+ u64 len, u64 unencoded_file_len, u64 unencoded_len,
+ u64 unencoded_offset, u32 compression, u32 encryption, void *user)
+{
+ int ret;
+ struct btrfs_receive *rctx = user;
+ char full_path[PATH_MAX];
+ struct encoded_iov encoded = {
+ .len = unencoded_file_len,
+ .unencoded_len = unencoded_len,
+ .unencoded_offset = unencoded_offset,
+ .compression = compression,
+ .encryption = encryption,
+ };
+ struct iovec iov[2] = {
+ { &encoded, sizeof(encoded) },
+ { (char *)data, len }
+ };
+
+ ret = path_cat_out(full_path, rctx->full_subvol_path, path);
+ if (ret < 0) {
+ error("encoded_write: path invalid: %s", path);
+ goto out;
+ }
+
+ ret = open_inode_for_write(rctx, full_path, true);
+ if (ret < 0)
+ goto out;
+
+ /*
+ * NOTE: encoded writes guarantee no partial writes,
+ * so we don't need to handle that possibility.
+ */
+ ret = pwritev2(rctx->write_fd, iov, 2, offset, RWF_ENCODED);
+ if (ret < 0) {
+ ret = -errno;
+ error("encoded_write: writing to %s failed: %m", path);
+ }
+out:
+ return ret;
+}
+
static struct btrfs_send_ops send_ops = {
.subvol = process_subvol,
.snapshot = process_snapshot,
@@ -1050,6 +1137,7 @@ static struct btrfs_send_ops send_ops = {
.chown = process_chown,
.utimes = process_utimes,
.update_extent = process_update_extent,
+ .encoded_write = process_encoded_write,
};
static int do_receive(struct btrfs_receive *rctx, const char *tomnt,
diff --git a/common/send-stream.c b/common/send-stream.c
index 77d5cd04..1376e00b 100644
--- a/common/send-stream.c
+++ b/common/send-stream.c
@@ -354,6 +354,8 @@ static int read_and_process_cmd(struct btrfs_send_stream *sctx)
struct timespec mt;
u8 uuid[BTRFS_UUID_SIZE];
u8 clone_uuid[BTRFS_UUID_SIZE];
+ u32 compression;
+ u32 encryption;
u64 tmp;
u64 tmp2;
u64 ctransid;
@@ -362,6 +364,9 @@ static int read_and_process_cmd(struct btrfs_send_stream *sctx)
u64 dev;
u64 clone_offset;
u64 offset;
+ u64 unencoded_file_len;
+ u64 unencoded_len;
+ u64 unencoded_offset;
int len;
int xattr_len;
@@ -436,6 +441,23 @@ static int read_and_process_cmd(struct btrfs_send_stream *sctx)
TLV_GET(sctx, BTRFS_SEND_A_DATA, &data, &len);
ret = sctx->ops->write(path, data, offset, len, sctx->user);
break;
+ case BTRFS_SEND_C_ENCODED_WRITE:
+ TLV_GET_STRING(sctx, BTRFS_SEND_A_PATH, &path);
+ TLV_GET_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, &offset);
+ TLV_GET_U64(sctx, BTRFS_SEND_A_UNENCODED_FILE_LEN,
+ &unencoded_file_len);
+ TLV_GET_U64(sctx, BTRFS_SEND_A_UNENCODED_LEN, &unencoded_len);
+ TLV_GET_U64(sctx, BTRFS_SEND_A_UNENCODED_OFFSET,
+ &unencoded_offset);
+ TLV_GET_U32(sctx, BTRFS_SEND_A_COMPRESSION, &compression);
+ TLV_GET_U32(sctx, BTRFS_SEND_A_ENCRYPTION, &encryption);
+ TLV_GET(sctx, BTRFS_SEND_A_DATA, &data, &len);
+ ret = sctx->ops->encoded_write(path, data, offset, len,
+ unencoded_file_len,
+ unencoded_len, unencoded_offset,
+ compression, encryption,
+ sctx->user);
+ break;
case BTRFS_SEND_C_CLONE:
TLV_GET_STRING(sctx, BTRFS_SEND_A_PATH, &path);
TLV_GET_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, &offset);
diff --git a/common/send-stream.h b/common/send-stream.h
index 39901f86..607bc007 100644
--- a/common/send-stream.h
+++ b/common/send-stream.h
@@ -66,6 +66,10 @@ struct btrfs_send_ops {
struct timespec *mt, struct timespec *ct,
void *user);
int (*update_extent)(const char *path, u64 offset, u64 len, void *user);
+ int (*encoded_write)(const char *path, const void *data, u64 offset,
+ u64 len, u64 unencoded_file_len, u64 unencoded_len,
+ u64 unencoded_offset, u32 compression,
+ u32 encryption, void *user);
};
int btrfs_read_and_process_send_stream(int fd,
diff --git a/stubs.h b/stubs.h
index b39f8a69..d0ad0d06 100644
--- a/stubs.h
+++ b/stubs.h
@@ -1,6 +1,8 @@
#ifndef _BTRFS_STUBS_H
#define _BTRFS_STUBS_H
+#include <fcntl.h>
+#include <linux/fs.h>
#include <sys/types.h>
struct iovec;
@@ -8,4 +10,41 @@ struct iovec;
ssize_t pwritev2(int fd, const struct iovec *iov, int iovcnt, off_t offset,
int flags);
+#ifndef O_ALLOW_ENCODED
+#define O_ALLOW_ENCODED 040000000
#endif
+
+#ifndef RWF_ENCODED
+enum {
+ ENCODED_IOV_COMPRESSION_NONE,
+#define ENCODED_IOV_COMPRESSION_NONE ENCODED_IOV_COMPRESSION_NONE
+ ENCODED_IOV_COMPRESSION_ZLIB,
+#define ENCODED_IOV_COMPRESSION_ZLIB ENCODED_IOV_COMPRESSION_ZLIB
+ ENCODED_IOV_COMPRESSION_LZO,
+#define ENCODED_IOV_COMPRESSION_LZO ENCODED_IOV_COMPRESSION_LZO
+ ENCODED_IOV_COMPRESSION_ZSTD,
+#define ENCODED_IOV_COMPRESSION_ZSTD ENCODED_IOV_COMPRESSION_ZSTD
+ ENCODED_IOV_COMPRESSION_TYPES = ENCODED_IOV_COMPRESSION_ZSTD,
+};
+
+enum {
+ ENCODED_IOV_ENCRYPTION_NONE,
+#define ENCODED_IOV_ENCRYPTION_NONE ENCODED_IOV_ENCRYPTION_NONE
+ ENCODED_IOV_ENCRYPTION_TYPES = ENCODED_IOV_ENCRYPTION_NONE,
+};
+
+struct encoded_iov {
+ __aligned_u64 len;
+ __aligned_u64 unencoded_len;
+ __aligned_u64 unencoded_offset;
+ __u32 compression;
+ __u32 encryption;
+};
+
+#define ENCODED_IOV_SIZE_VER0 32
+
+/* encoded (e.g., compressed and/or encrypted) IO */
+#define RWF_ENCODED ((__kernel_rwf_t)0x00000020)
+#endif /* RWF_ENCODED */
+
+#endif /* _BTRFS_STUBS_H */
--
2.28.0
