The initial proposal for file attributes was built on simply doing
SETFLAGS but this builds on an old and non-extensible interface that has
no direct mapping for all inode flags. There's a unified interface
fileattr that covers file attributes and xflags, it should be possible
to add new bits.
On the protocol level the value is copied as-is in the original inode
but this does not provide enough information how to apply the bits on
the receiving side. Eg. IMMUTABLE flag prevents any changes to the file
and has to be handled manually.
The receiving side does not apply the bits yet, only parses it from the
stream.
Signed-off-by: David Sterba <dsterba@suse.com>
First, add a --proto option to allow specifying the desired send
protocol version. It defaults to one, the original version. In a couple
of releases once people are aware that protocol revisions are happening,
we can change it to default to zero, which means the latest version
supported by the kernel. This is based on Dave Sterba's patch.
Also add a --compressed-data flag to instruct the kernel to use
encoded_write commands for compressed extents. This requires an explicit
opt in separate from the protocol version because:
1. The user may not want compression on the receiving side, or may want
a different compression algorithm/level on the receiving side.
2. It has a soft requirement for kernel support on the receiving side
(btrfs-progs can fall back to decompressing and writing if the kernel
doesn't support BTRFS_IOC_ENCODED_WRITE, but the user may not be
prepared to pay that CPU cost). Going forward, since it's easier to
update progs than the kernel, I think we'll want to make new send
features that require kernel support opt-in, whereas anything that
only requires a progs update can happen automatically.
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Update our copy of send.h from the kernel. This adds the new commands
and attributes for v2 as well as explicit enum numbering.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In send stream v2, write commands can now be an arbitrary size. For that
reason, we can no longer allocate a fixed array in sctx for read_cmd.
Instead, read_cmd dynamically allocates sctx->read_buf. To avoid
needless reallocations, we reuse read_buf between read_cmd calls by also
keeping track of the size of the allocated buffer in sctx->read_buf_sz.
We do the first allocation of the old default size at the start of
processing the stream, and we only reallocate if we encounter a command
that needs a larger buffer.
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Headers that are only exported and not used for build do not need the
BTRFS_FLAT_INCLUDES switch (between local and installed headers). Now
that there are local copies of the shared headers drop the respective
part from local headers.
Signed-off-by: David Sterba <dsterba@suse.com>
To drop sizes.h from exported headers, replace the few SZ_ constants
from the existing exported headers (ctree.h, send.h). It would be nice
to use them in the long run but right now it would prevent unexporting
the sizes.h file.
Signed-off-by: David Sterba <dsterba@suse.com>
The header contains the protocol definitions and is almost exactly the
same as the kernel version, move it to the proper directory.
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba
Omar Sandoval
Boris Burkov