Move the LZ77 codec in cifs.ko to smb/common/ so both the SMB
client and ksmbd can use it.
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
@dst buffer is allocated with same size as @src, which, for good
compression cases, works fine.
However, when compression goes bad (e.g. random bytes payloads), the
compressed size can increase significantly, and even by stopping the
main loop at 7/8 of @slen, writing leftover literals could write past
the end of @dst because of LZ77 metadata.
To fix this, add lz77_compressed_alloc_size() helper to compute the
correct allocation size for @dst, accounting for metadata and worst
cast scenario (all literals).
While this is overprovisioning memory, it's not only correct, but also
allows lz77_compress() main loop to run without ever checking @dst
limits (i.e. a perf improvement).
Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
Make some preparatory cleanups prior to running a script to organise the
function declarations within the fs/smb/client/ headers. These include:
(1) Remove "inline" from the dummy cifs_proc_init/clean() functions as
they are in a .c file.
(2) Move should_compress()'s kdoc comment to the .c file and remove kdoc
markers from the comments.
(3) Rename CIFS_ALLOW_INSECURE_LEGACY in #endif comments to have CONFIG_
on the front to allow the script to recognise it.
(4) Don't let comments have bare words at the left margin as that confused
the simplistic function detection code in the script.
(5) Adjust some argument lists so that when and if the cleanup script is
run they don't end up over 100 chars.
(6) Fix a few comments to have missing '*' added or the "*/" moved to
their own lines so that checkpatch doesn't moan over the cleanup
script patch.
(7) Move struct cifs_calc_sig_ctx to cifsglob.h.
(8) Remove some __KERNEL__ conditionals.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Add a tracepoint to log EIO errors and give it the capacity to convey up to
two integers of information. This is then wrapped with three functions:
int smb_EIO(enum smb_eio_trace trace)
int smb_EIO1(enum smb_eio_trace trace, unsigned long info)
int smb_EIO2(enum smb_eio_trace trace, unsigned long info,
unsigned long info2)
depending on how many bits of info are desired to be logged with any
particular trace. The functions all return -EIO and can be used in place
of -EIO.
The trace argument is an enum value that gets translated to a string when
the trace is printed.
This makes is easier to log EIO instances when the client is under high
load than turning on a printk wrapper such as cifs_dbg(). Granted, EIO
could have its own separate EIO printing since EIO shouldn't happen.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
collect_sample() is used to gather samples of the data in a Write op for
analysis to try and determine if the compression algorithm is likely to
achieve anything more quickly than actually running the compression
algorithm.
However, collect_sample() assumes that the data it is going to be sampling
is stored in an ITER_XARRAY-type iterator (which it now should never be)
and doesn't actually check that it is before accessing the underlying
xarray directly.
Fix this by replacing the code with a loop that just uses the standard
iterator functions to sample every other 2KiB block, skipping the
intervening ones. It's not quite the same as the previous algorithm as it
doesn't necessarily align to the pages within an ordinary write from the
pagecache.
Note that the btrfs code from which this was derived samples the inode's
pagecache directly rather than the iterator - but that doesn't necessarily
work for network filesystems if O_DIRECT is in operation.
Fixes: 94ae8c3fee ("smb: client: compress: LZ77 code improvements cleanup")
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
cc: Enzo Matsumiya <ematsumiya@suse.de>
cc: Shyam Prasad N <sprasad@microsoft.com>
cc: Tom Talpey <tom@talpey.com>
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
The if condition in collect_sample: can never be satisfied
because of a logical contradiction. The indicated dead code
may have performed some action; that action will never occur.
Fixes: 94ae8c3fee ("smb: client: compress: LZ77 code improvements cleanup")
Signed-off-by: Advait Dhamorikar <advaitdhamorikar@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Change is_compressible() return type to bool, use WARN_ON_ONCE(1) for
internal errors and return false for those.
Renames:
check_repeated_data -> has_repeated_data
check_ascii_bytes -> is_mostly_ascii (also refactor into a single loop)
calc_shannon_entropy -> has_low_entropy
Also wraps "wreq->Length" in le32_to_cpu() in should_compress() (caught
by sparse).
Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Suggested-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Using uninitialized value "bkt" when calling "kfree"
Fixes: 13b68d44990d ("smb: client: compress: LZ77 code improvements cleanup")
Signed-off-by: Qianqiang Liu <qianqiang.liu@163.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
The dst pointer may not be initialized when calling kvfree(dst)
Fixes: 13b68d44990d9 ("smb: client: compress: LZ77 code improvements cleanup")
Signed-off-by: Qianqiang Liu <qianqiang.liu@163.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
- Check data compressibility with some heuristics (copied from
btrfs):
- should_compress() final decision is is_compressible(data)
- Cleanup compress/lz77.h leaving only lz77_compress() exposed:
- Move parts to compress/lz77.c, while removing the rest of it
because they were either unused, used only once, were
implemented wrong (thanks to David Howells for the help)
- Updated the compression parameters (still compatible with
Windows implementation) trading off ~20% compression ratio
for ~40% performance:
- min match len: 3 -> 4
- max distance: 8KiB -> 1KiB
- hash table type: u32 * -> u64 *
Known bugs:
This implementation currently works fine in general, but breaks with
some payloads used during testing. Investigation ongoing, to be
fixed in a next commit.
Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Co-developed-by: David Howells <dhowells@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Move SMB3.1.1 compression code into experimental config option,
and fix the compress mount option. Implement unchained LZ77
"plain" compression algorithm as per MS-XCA specification
section "2.3 Plain LZ77 Compression Algorithm Details".
Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
