Now default compression is lz4, which can stop
compression process by itself on incompressible data.
If there are additional size checks -
we will only make our compressratio worse.
New usable compression thresholds are:
- less than BPE_PAYLOAD_SIZE (embedded_data feature);
- at least one saved sector.
Old 12.5% threshold is left to minimize affect
on existing user expectations of CPU utilization.
If data wasn't compressed - it will be saved as
ZIO_COMPRESS_OFF, so if we really need to recompress
data without ashift info and check anything -
we can just compress it with zero threshold.
So, we don't need a new feature flag here!
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: George Melikov <mail@gmelikov.ru>
Closes#9416
If compression happend, any garbage past the compress size was not
zeroed out.
If compression didn't happen, then the payload size was still set to
the rounded-up return from zio_compress_data(), which is dependent on
the input, which is not necessarily the logical size.
So that's all fixed too, mostly from stealing the math from zio.c.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
This commit changes the frontend zio_compress_data and
zio_decompress_data APIs to take ABD points instead of buffer pointers.
All callers are updated to match. Any that already have an appropriate
ABD nearby now use it directly, while at the rest we create an one.
Internally, the ABDs are passed through to the provider directly.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
This is updating zstream to use the zio_compress calls rather than using
its own dispatch. Since that was fairly entangled, some refactoring
included.
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
sscanf returns number of items parsed on success and EOF on failure.
Reviewed-by: Adam Moss <c@yotes.com>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Rob Norris <robn@despairlabs.com>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#16198
In the zstream code, Coverity reported:
"The argument could be controlled by an attacker, who could invoke the
function with arbitrary values (for example, a very high or negative
buffer size)."
It did not report this in the kernel. This is likely because the
userspace code stored this in an int before passing it into the
allocator, while the kernel code stored it in a uint32_t.
However, this did reveal a potentially real problem. On 32-bit systems
and systems with only 4GB of physical memory or less in general, it is
possible to pass a large enough value that the system will hang. Even
worse, on Linux systems, the kernel memory allocator is not able to
support allocations up to the maximum 4GB allocation size that this
allows.
This had already been limited in userspace to 64MB by
`ZFS_SENDRECV_MAX_NVLIST`, but we need a hard limit in the kernel to
protect systems. After some discussion, we settle on 256MB as a hard
upper limit. Attempting to receive a stream that requires more memory
than that will result in E2BIG being returned to user space.
Reported-by: Coverity (CID-1529836)
Reported-by: Coverity (CID-1529837)
Reported-by: Coverity (CID-1529838)
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14285
Coverity has long complained about the checksum being uninitialized if
an END record is processed before its BEGIN record. This should not
happen, but there was no code to check for it. I had left this unfixed
since it was a low priority issue, but then
9f4ede63d2 added another instance of this.
I am making an effort to "hold the line" to keep new coverity defect
reports from going unaddressed, so I find myself forced to fix this much
earlier than I had originally planned to address it.
The solution is to maintain a counter and a flag. Then use VERIFY
statements to verify the following runtime constraints:
* Every record either has a corresponding BEGIN record, is a BEGIN
record or is the end of stream END record for replication streams.
* BEGIN records cannot be nested. i.e. There must be an END record
before another BEGIN record may be seen.
Failure to meet these constraints will cause the program to exit.
This is sufficient to ensure that the checksum is never accessed when
uninitialized.
Reported-by: Coverity (CID 1524578)
Reported-by: Coverity (CID 1524633)
Reported-by: Coverity (CID 1527295)
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Damian Szuberski <szuberskidamian@gmail.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14176
As new compression algorithms are added to ZFS, it could be useful for
people to recompress data with new algorithms. There is currently no
mechanism to do this aside from copying the data manually into a new
filesystem with the new algorithm enabled. This tool allows the
transformation to happen through zfs send, allowing it to be done
efficiently to remote systems and in an incremental fashion.
A new zstream command is added that decompresses WRITE records and
then recompresses them with a provided algorithm, and then re-emits
the modified send stream. It may also be possible to re-compress
embedded block pointers, but that was not attempted for the initial
version.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#14106
