was that kernel update the only upgrade? tough to separate.....
I've found that throughout numerous kde upgrades, the nepomuk/strigi file system search "stuff" goes a bit bonkers. Solutions range from disabling them (my fav choice), or zeroing their databases and let them start over (they still will do a serious disk crawl upon first startup).
Still a big fan of the whole reiserfs underpinnings, and what he had in mind. Just had major bad choices in other places in his life
I quit reiserfs when it/he became a jailed "chroot" filesystem (pun intended!). Now, I am an xfs fan due to it's long history, full toolsuite, and zero complaints if you have 200k files in a single directory, along with superior performance for large files, and no major penalties for small files. UFS, EXTx, and numerous others simply can't handle those situtations well. (my xfs filesystems range from 10G to 16Tbytes, with only one significant dataloss of about 10% after multiple underlying disks failed; lousy power and too many lightening spikes on the local power grid).
Thus, for many years, reiserfs was my primary choice, xfs has now been my mainstay in server (NAS, SAN & LVM), desktop, notebook and SSD without any hassle (but, very thin toolset and recovery support). Surprisingly, a very poor (my typo) raid device failure and recovery (dirty state that looked clean), the xfs tools performed admirably, and essentially, no underlying updates were required to support SSD's on one end, or massive SANs on the other. FWIW, EXT work just fine for 90% of desktop users, no doubt. I'll wait til 5.x kernel is out before I venture into btrfs again (just a needed, and good idea, but early upgrade to the EXTfs line....)
Just food for thought. I have a couple 5-8 year old but full production gentoo systems fully updated (headless....) with reiserfs 3.x filesystems running 3.3 kernel without any issues after years of the reiserfs filesystem, and thousands of hours of runtime. Thus, my thought that kde's file index might be your unwanted friend. reiser has always been super friendly and performance clean (compared to EXTx) for massive directories and directory crawling.
Hope those help. good luck!