Fedora Hardware :: F12 Boot Fails - Short Block Read

My F12 installation, which was installed on an HP tx2500z laptop and has been operating relatively well since January, now fails to boot after a frozen screen precipitated a forced shutdown. On reboot, I was dropped into a shell with the error message "Error reading block 1546 (Attempt to read block from file system resulted in a short read) while getting next inode from scan." recommending to run fsck manually. During the fsck run, after a substantial number of Pass 1 inode count corrections, the "Error reading block" message reappeared, with the question "Ignore error<y>" to which I answered "y".

fsck responded with "Force rewrite<y>". Since I did not know what would be written here, I said "no". I then forced shutdown, rebooted into Windows, and searched for further guidance. One suggestion was to run fsck -y on the affected partition. My laptop drive has four partitions, the first two being allocated to Windows and an HP supplied repair partition. sda3 is a tiny boot partition (100 MB), and sda4/5 is the LVM remainder.

fsck -y /dev/sda3 told me the boot partition was fine.
fsck -y /dev/sda4 stopped immediately and asked "Could this be a zero-length file partition?". Given the ext3 structure, I suppose the correct answer is yes.
fsck -y /dev/sda5 told me fsck.LVM2_Member: not found.

Following this, I then attempted again to reboot, and ran fsck without options. Once again, during Pass 1, Block 1546 exhibited the short read error, again asking about a rewrite - which I once again answered no. Pass 1 completed with another substantial number of inode count corrections, and Pass 2 started - immediately generating the message:

'passwd' in /etc/pam.d (65556) has deleted/unused node 7831. Clear<y>

After some hesitancy, I said "yes", and of course a second similar message appeared. I was brave enough to answer "yes" six more times, with the first two referring to /etc/pam.d inodes, and the next four referring to /etc/security/console.apps inodes. The eighth message, also similar, referred to inodes elsewhere - but by now I did not dare to continue and forced shutdown. Is this repairable, and if so, how?