Commit Graph

4 Commits

Author SHA1 Message Date
Petros Koutoupis bd95f00d4b
Fixed LDADD library links in Makefiles for cross compilation builds
When building on native dev system, there are no issues but when
cross-compiling for target system, some linker errors are observed.
The only way to avoid these errors is by adjusting the Makefile.am
of those various components to add the library dependencies.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Petros Koutoupis <petros@petroskoutoupis.com>
Closes #10304
2020-05-09 10:17:08 -07:00
Brian Behlendorf 6de3e59bdd
Fix unitialized variable in `zstream redup` command
Fix uninitialized variable in `zstream redup` command.  The compiler
may determine the 'stream_offset' variable can be uninitialized
because not all rdt_lookup() exit paths set it.  This should never
happen in practice as documented by the assert, but initialize it
regardless to resolve the warning.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #10241
Closes #10244
2020-04-23 15:54:38 -07:00
Brian Behlendorf 8080848254
Minor `zstream redup` command fixes
* Fix uninitialized variable in `zstream redup` command.  The
  'rdt.ddt_count' variable is uninitialized because it was
  allocated from the stack and not globally.  Initialize it.
  This was reported by gcc when compiling with debugging enabled.

    zstream_redup.c:157:16: error: 'rdt.ddt_count' may be used
    uninitialized in this function [-Werror=maybe-uninitialized]

* Remove the cmd/zstreamdump/.gitignore file.  It's no longer
  needed now that the zstreamdump command is a script.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #10192
2020-04-10 21:10:09 -07:00
Matthew Ahrens c618f87cd2
Add `zstream redup` command to convert deduplicated send streams
Deduplicated send and receive is deprecated.  To ease migration to the
new dedup-send-less world, the commit adds a `zstream redup` utility to
convert deduplicated send streams to normal streams, so that they can
continue to be received indefinitely.

The new `zstream` command also replaces the functionality of
`zstreamdump`, by way of the `zstream dump` subcommand.  The
`zstreamdump` command is replaced by a shell script which invokes
`zstream dump`.

The way that `zstream redup` works under the hood is that as we read the
send stream, we build up a hash table which maps from `<GUID, object,
offset> -> <file_offset>`.

Whenever we see a WRITE record, we add a new entry to the hash table,
which indicates where in the stream file to find the WRITE record for
this block. (The key is `drr_toguid, drr_object, drr_offset`.)

For entries other than WRITE_BYREF, we pass them through unchanged
(except for the running checksum, which is recalculated).

For WRITE_BYREF records, we change them to WRITE records.  We find the
referenced WRITE record by looking in the hash table (for the record
with key `drr_refguid, drr_refobject, drr_refoffset`), and then reading
the record header and payload from the specified offset in the stream
file.  This is why the stream can not be a pipe.  The found WRITE record
replaces the WRITE_BYREF record, with its `drr_toguid`, `drr_object`,
and `drr_offset` fields changed to be the same as the WRITE_BYREF's
(i.e. we are writing the same logical block, but with the data supplied
by the previous WRITE record).

This algorithm requires memory proportional to the number of WRITE
records (same as `zfs send -D`), but the size per WRITE record is
relatively low (40 bytes, vs. 72 for `zfs send -D`).  A 1TB send stream
with 8KB blocks (`recordsize=8k`) would use around 5GB of RAM to
"redup".

Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10124 
Closes #10156
2020-04-10 10:39:55 -07:00