LS-BDD

LS-BDD is a block device driver that implements log-structured storage based on B+-tree, RB-tree, Skiplist and Hashtable data structures. Driver is based on BIO request management and supports BIO split.

For more info - see presentation v1

Compatable with Linux Kernel 6.8

Usage

Highly recommended to test/use the driver using a VM, to prevent data coruption.

Initialisation:

make
insmod lsbdd.ko
echo "ds_name" > /sys/module/lsbdd/parameters/set_data_structure
echo "index path" > /sys/module/lsbdd/parameters/set_redirect_bd

ds_name - one of available data structures to store the mapping ("bt", "ht", "sl", "rb") index - postfix for a 'device in the middle' (prefix is 'lsvbd'), path - to which block device to redirect

All this steps can be reduced to make init

Sending requests:

Initialisation example:

...
echo "1 /dev/vdb" > /sys/module/lsbdd/parameters/set_redirect_bd
cat /sys/module/lsbdd/parameters/get_bd_names // to get the links

Writing

dd if=/dev/urandom of=/dev/lsvbd1 oflag=direct bs=2K count=10;

Reading

dd of=test2.txt if=/dev/lsvbd1 iflag=direct bs=4K count=10; 

Testing

After making some changes you can check a lot of obvious cases using auto-tests:

python3 ../test/autotest.py -vbd="lsvbd1" -n=5 -fs=-1 -bs=0 -m=seq

In addition you can use the provided fio tests, that time the execution and use pattern-verify process.

make fio_verify WO=randwrite RO=randread FS=1000 WBS=8 RBS=8

Options description is provided in Makefile.

Although, if you need more customizable fio testing - you can check test/fio/ for more predefined configs. Run them by:

fio test/fio/_

Basic test - "ftv_4_8/ftv_8_4" Also including the .sh versions (better use them for this moment)

License

Distributed under the GPL-2.0 License.