linux/fs
Stefan Behrens c2c71324ec Btrfs: allow omitting stream header and end-cmd for btrfs send
Two new flags are added to allow omitting the stream header and the
end command for btrfs send streams. This is used in cases where you
send multiple snapshots back-to-back in one stream.

This used to be encoded like this (with 2 snapshots in this example):
<stream header> + <sequence of commands> + <end cmd> +
<stream header> + <sequence of commands> + <end cmd> + EOF

The new format (if the two new flags are used) is this one:
<stream header> + <sequence of commands> +
                  <sequence of commands> + <end cmd>

Note that the currently existing receivers treat <end cmd> only as
an indication that a new <stream header> is following. This means,
you can just skip the sequence <end cmd> <stream header> without
loosing compatibility. As long as an EOF is following, the currently
existing receivers handle the new format (if the two new flags are
used) exactly as the old one.

So what is the benefit of this change? The goal is to be able to use
a single stream (one TCP connection) to multiplex a request/response
handshake plus Btrfs send streams, all in the same stream. In this
case you cannot evaluate an EOF condition as an end of the Btrfs send
stream. You need something else, and the <end cmd> is just perfect
for this purpose.

The summary is:
The format change is driven by the need to send several Btrfs send
streams over a single TCP connections, with the ability for a repeated
request/response handshake in the middle. And this format change does
not break any existing tool, it is completely compatible.

You could compare the old behaviour of the Btrfs send stream to the
one of ftp where you need a seperate request/response channel and
newly opened data transfer channels for each file, while the new
behaviour is more like http using a single stream for everything.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2013-05-06 15:54:44 -04:00
..
9p fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
adfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
affs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
afs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
autofs4 fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
befs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
bfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
btrfs Btrfs: allow omitting stream header and end-cmd for btrfs send 2013-05-06 15:54:44 -04:00
cachefiles FS-Cache: Mark cancellation of in-progress operation 2012-12-20 22:34:00 +00:00
ceph fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
cifs cifs: Allow passwords which begin with a delimitor 2013-04-10 15:54:14 -05:00
coda fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
configfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
cramfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
debugfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
devpts fs: Limit sys_mount to only request filesystem modules (Part 2). 2013-03-07 01:08:55 -08:00
dlm hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
ecryptfs ecryptfs: close rmmod race 2013-04-09 14:08:16 -04:00
efs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
exofs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
exportfs hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
ext2 ext2: Fix BUG_ON in evict() on inode deletion 2013-03-13 15:23:44 +01:00
ext3 ext3: Fix format string issues 2013-03-11 22:05:56 +01:00
ext4 ext4: fix big-endian bugs which could cause fs corruptions 2013-04-03 12:37:17 -04:00
f2fs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
fat fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
freevxfs fs: Readd the fs module aliases. 2013-03-12 18:55:21 -07:00
fscache hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
fuse fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
gfs2 GFS2: Issue discards in 512b sectors 2013-04-05 17:55:13 +01:00
hfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
hfsplus hfsplus: fix potential overflow in hfsplus_file_truncate() 2013-04-17 16:10:45 -07:00
hostfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2013-03-13 15:47:50 -07:00
hpfs fs: Limit sys_mount to only request filesystem modules. (Part 3) 2013-03-11 07:09:48 -07:00
hppfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
hugetlbfs hugetlbfs: stop setting VM_DONTDUMP in initializing vma(VM_HUGETLB) 2013-04-17 16:10:44 -07:00
isofs fs: Readd the fs module aliases. 2013-03-12 18:55:21 -07:00
jbd jbd: don't wake kjournald unnecessarily 2013-01-14 22:50:45 +01:00
jbd2 jbd2: fix use after free in jbd2_journal_dirty_metadata() 2013-03-11 13:24:56 -04:00
jffs2 fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
jfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
lockd Merge branch 'for-3.9' of git://linux-nfs.org/~bfields/linux 2013-02-28 18:02:55 -08:00
logfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
minix fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
ncpfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
nfs NFS client bugfixes for Linux 3.9 2013-04-10 10:26:49 -07:00
nfs_common nfs_common: Update the translation between nfsv3 acls linux posix acls 2013-02-13 06:15:14 -08:00
nfsd nfsd4: reject "negative" acl lengths 2013-03-26 16:18:27 -04:00
nilfs2 fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
nls
notify hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
ntfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
ocfs2 fs: Limit sys_mount to only request filesystem modules (Part 2). 2013-03-07 01:08:55 -08:00
omfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
openpromfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
proc kthread: Prevent unpark race which puts threads on the wrong cpu 2013-04-12 14:18:43 +02:00
pstore A few fixes to reduce places where pstore might hang 2013-02-21 09:38:18 -08:00
qnx4 fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
qnx6 fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
quota quota: add missing use of dq_data_lock in __dquot_initialize 2013-03-11 22:05:56 +01:00
ramfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
reiserfs reiserfs: Fix warning and inode leak when deleting inode with xattrs 2013-03-29 17:08:43 +01:00
romfs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
squashfs fs: Limit sys_mount to only request filesystem modules. (Part 3) 2013-03-11 07:09:48 -07:00
sysfs sysfs fixes for 3.9-rc4 2013-03-28 15:52:14 -07:00
sysv fs: Readd the fs module aliases. 2013-03-12 18:55:21 -07:00
ubifs UBIFS: make space fixup work in the remount case 2013-03-14 11:20:22 +02:00
udf fs: Limit sys_mount to only request filesystem modules. (Part 3) 2013-03-11 07:09:48 -07:00
ufs fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
xfs - Fix for a potential infinite loop which was introduced in 4d559a3bcb 2013-03-19 15:17:40 -07:00
aio.c aio: fix possible invalid memory access when DEBUG is enabled 2013-04-26 07:56:18 -07:00
anon_inodes.c get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero 2013-02-26 02:46:11 -05:00
attr.c
bad_inode.c lseek: the "whence" argument is called "whence" 2012-12-17 17:15:12 -08:00
binfmt_aout.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
binfmt_elf_fdpic.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
binfmt_elf.c fs/binfmt_elf.c: fix hugetlb memory check in vma_dump_size() 2013-04-17 16:10:44 -07:00
binfmt_em86.c exec: use -ELOOP for max recursion depth 2012-12-17 17:15:23 -08:00
binfmt_flat.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
binfmt_misc.c fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
binfmt_script.c exec: do not leave bprm->interp on stack 2012-12-20 17:40:19 -08:00
binfmt_som.c get rid of pt_regs argument of ->load_binary() 2012-11-28 21:53:38 -05:00
bio-integrity.c
bio.c Revert "block: add missing block_bio_complete() tracepoint" 2013-04-18 09:00:26 -07:00
block_dev.c loop: prevent bdev freeing while device in use 2013-04-01 15:48:47 -07:00
buffer.c Merge branch 'for-3.9/core' of git://git.kernel.dk/linux-block 2013-02-28 12:52:24 -08:00
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
compat.c Fix: compat_rw_copy_check_uvector() misuse in aio, readv, writev, and security keys 2013-03-12 11:05:45 -07:00
coredump.c coredump: remove redundant defines for dumpable states 2013-02-27 19:10:11 -08:00
coredump.h
dcache.c Nest rename_lock inside vfsmount_lock 2013-03-26 18:25:57 -04:00
dcookies.c
direct-io.c fs: Fix possible use-after-free with AIO 2013-02-22 23:31:36 -05:00
drop_caches.c
eventfd.c fs, eventfd: add procfs fdinfo helper 2012-12-17 17:15:27 -08:00
eventpoll.c epoll: prevent missed events on EPOLL_CTL_MOD 2013-01-02 09:16:43 -08:00
exec.c coredump: remove redundant defines for dumpable states 2013-02-27 19:10:11 -08:00
fcntl.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
fhandle.c Merge branch 'for-3.8' of git://linux-nfs.org/~bfields/linux 2012-12-20 14:04:11 -08:00
fifo.c
file_table.c cache the value of file_inode() in struct file 2013-03-01 19:48:30 -05:00
file.c locking: Various static lock initializer fixes 2013-02-19 08:42:45 +01:00
filesystems.c fs: Limit sys_mount to only request filesystem modules. 2013-03-03 19:36:31 -08:00
fs_struct.c constify path_get/path_put and fs_struct.c stuff 2013-03-01 23:51:07 -05:00
fs-writeback.c 2 writeback fixes 2013-02-28 13:21:44 -08:00
generic_acl.c
inode.c vfs: Revert spurious fix to spinning prevention in prune_icache_sb 2013-04-13 16:13:55 -07:00
internal.h Don't bother with redoing rw_verify_area() from default_file_splice_from() 2013-03-21 13:11:11 -04:00
ioctl.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
ioprio.c
Kconfig fuse: Move CUSE Kconfig entry from fs/Kconfig into fs/fuse/Kconfig 2013-01-17 13:08:45 +01:00
Kconfig.binfmt
libfs.c vfs: drop vmtruncate 2012-12-20 18:46:29 -05:00
locks.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
Makefile f2fs: update Kconfig and Makefile 2012-12-11 13:43:42 +09:00
mbcache.c
mount.h
mpage.c
namei.c vfs: don't BUG_ON() if following a /proc fd pseudo-symlink results in a symlink 2013-03-08 09:03:07 -08:00
namespace.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-04-09 12:22:49 -07:00
no-block.c
open.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-03-03 13:23:03 -08:00
pipe.c vfs: fix pipe counter breakage 2013-03-12 08:29:17 -07:00
pnode.c vfs: Carefully propogate mounts across user namespaces 2013-03-27 07:50:05 -07:00
pnode.h vfs: Carefully propogate mounts across user namespaces 2013-03-27 07:50:05 -07:00
posix_acl.c
proc_namespace.c
read_write.c vfs/splice: Fix missed checks in new __kernel_write() helper 2013-03-27 09:24:02 -07:00
read_write.h
readdir.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
select.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
seq_file.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-03-03 13:23:03 -08:00
signalfd.c fs, epoll: add procfs fdinfo helper 2012-12-17 17:15:27 -08:00
splice.c Don't bother with redoing rw_verify_area() from default_file_splice_from() 2013-03-21 13:11:11 -04:00
stack.c
stat.c switch vfs_getattr() to struct path 2013-02-26 02:46:08 -05:00
statfs.c vfs: fix user_statfs to retry once on ESTALE errors 2012-12-20 18:50:07 -05:00
super.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
sync.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
timerfd.c compat: restore timerfd settime and gettime compat syscalls 2013-03-02 09:35:13 -05:00
utimes.c vfs: allow utimensat() calls to retry once on an ESTALE error 2012-12-20 18:50:08 -05:00
xattr_acl.c
xattr.c vfs: make lremovexattr retry once on ESTALE error 2012-12-20 18:50:11 -05:00