On Wed, Jan 23, 2013 at 1:04 PM, Chen Yang <[email protected]> wrote: > From: Chen Yang <[email protected]> > Date: Fri, 18 Jan 2013 14:54:31 +0800 > Subject: [PATCH] Btrfs-progs/receive: sparse and pre-allocated file support > for btrfs-send mechanism > > When sending a file with sparse or pre-allocated part, > these parts will be sent as ZERO streams, and it's unnecessary. > > To improve this, we add a punch command on the sending side, so the > receiving side changed with it. The main change is adding the punch > processing to receive command. > > Signed-off-by: Cheng Yang <[email protected]> > --- > cmds-receive.c | 27 +++++++++++++++++++++++++++ > send-stream.c | 6 ++++++ > send-stream.h | 1 + > send.h | 3 ++- > 4 files changed, 36 insertions(+), 1 deletions(-) > > diff --git a/cmds-receive.c b/cmds-receive.c > index a8be6fa..74cbfc4 100644 > --- a/cmds-receive.c > +++ b/cmds-receive.c > @@ -37,6 +37,7 @@ > #include <sys/types.h> > #include <sys/xattr.h> > #include <uuid/uuid.h> > +#include <linux/falloc.h> > > #include "ctree.h" > #include "ioctl.h" > @@ -508,6 +509,31 @@ out: > return ret; > } > > +static int process_punch(const char *path, u64 offset, u64 len, void *user) > +{ > + int ret = 0; > + struct btrfs_receive *r = user; > + char *full_path = path_cat(r->full_subvol_path, path); > + > + ret = open_inode_for_write(r, full_path); > + if (ret < 0) > + goto out; > + > + ret = fallocate(r->write_fd, > + FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, > + offset, len); > + if (ret < 0) { > + ret = -errno; > + fprintf(stderr, "ERROR: punch %s failed. %s\n", > + path, strerror(-ret)); > + goto out; > + } > + > +out: > + free(full_path); > + return ret; > +} > + > static int process_write(const char *path, const void *data, u64 offset, > u64 len, void *user) > { > @@ -777,6 +803,7 @@ struct btrfs_send_ops send_ops = { > .link = process_link, > .unlink = process_unlink, > .rmdir = process_rmdir, > + .punch = process_punch, > .write = process_write, > .clone = process_clone, > .set_xattr = process_set_xattr, > diff --git a/send-stream.c b/send-stream.c > index 55fa728..9f3ede7 100644 > --- a/send-stream.c > +++ b/send-stream.c > @@ -362,6 +362,12 @@ static int read_and_process_cmd(struct btrfs_send_stream > *s) > TLV_GET_STRING(s, BTRFS_SEND_A_PATH, &path); > ret = s->ops->rmdir(path, s->user); > break; > + case BTRFS_SEND_C_PUNCH: > + TLV_GET_STRING(s, BTRFS_SEND_A_PATH, &path); > + TLV_GET_U64(s, BTRFS_SEND_A_FILE_OFFSET, &offset); > + TLV_GET_U64(s, BTRFS_SEND_A_SIZE, &len); > + ret = s->ops->punch(path, offset, len, s->user); > + break; > case BTRFS_SEND_C_WRITE: > TLV_GET_STRING(s, BTRFS_SEND_A_PATH, &path); > TLV_GET_U64(s, BTRFS_SEND_A_FILE_OFFSET, &offset); > diff --git a/send-stream.h b/send-stream.h > index b69b7f1..f83f2ac 100644 > --- a/send-stream.h > +++ b/send-stream.h > @@ -34,6 +34,7 @@ struct btrfs_send_ops { > int (*link)(const char *path, const char *lnk, void *user); > int (*unlink)(const char *path, void *user); > int (*rmdir)(const char *path, void *user); > + int (*punch)(const char *path, u64 offset, u64 len, void *user); > int (*write)(const char *path, const void *data, u64 offset, u64 len, > void *user); > int (*clone)(const char *path, u64 offset, u64 len, > diff --git a/send.h b/send.h > index 9934e94..10a88d2 100644 > --- a/send.h > +++ b/send.h > @@ -20,7 +20,7 @@ > #include "ctree.h" > > #define BTRFS_SEND_STREAM_MAGIC "btrfs-stream" > -#define BTRFS_SEND_STREAM_VERSION 1 > +#define BTRFS_SEND_STREAM_VERSION 2 > > #define BTRFS_SEND_BUF_SIZE (1024 * 64) > #define BTRFS_SEND_READ_SIZE (1024 * 48) > @@ -80,6 +80,7 @@ enum btrfs_send_cmd { > BTRFS_SEND_C_WRITE, > BTRFS_SEND_C_CLONE, > > + BTRFS_SEND_C_PUNCH, > BTRFS_SEND_C_TRUNCATE, > BTRFS_SEND_C_CHMOD, > BTRFS_SEND_C_CHOWN,
I think this breaks the current protocol, because it changes the numbers for existing commands, starting from BTRFS_SEND_C_TRUNCATE. I don't think this will be acceptable for existing users. I think the new commands should be added after BTRFS_SEND_C_END command (unfortunately), like the snapper command that was added recently. Thanks, Alex. > -- > 1.7.7.6 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
