Support for TP-LINK RE305 V3

dsouza · March 28, 2023, 9:47pm

My RE305 v3 with OpenWrt 22.03 (being used as dumb access point) was constantly failing with the errors below:

SQUASHFS error: xz decompression failed, data probably corrupt
SQUASHFS error: Unable to read fragment cache entry 
SQUASHFS error: Unable to read page, block xxxx, size yyyy

Initially I thought that it could be a hardware problem with device's flash, but with factory firmware it was working perfectly.

Searching the web I've found this was a quite common problem with some Mediatek devices:

github.com/openwrt/openwrt

ramips/mt7621: SQUASHFS filesystem corruption

opened 06:24PM - 20 Oct 21 UTC

openwrt-bot

kernel target/ramips release/21.02 flyspray bug release/22.03

*crowston:* Supply the following if possible: - Device problem occurs on W…estern Digital My Net N750 - Software versions of OpenWrt/LEDE release, packages, etc. openwrt-21.02.0 strongswan, dnscrypt-proxy2, avahi-utils, luci-app-ddns - Steps to reproduce I installed openwrt-21.02.0-ath79-generic-wd_mynet-n750-squashfs-sysupgrade.bin on a Western Digital My Net N750 that had been running openwrt-19. The router seemed okay initially but after power cycling, it started reporting errors: Oct 17 12:20:37 router2 kernel: [ 38.613970] SQUASHFS error: xz decompression failed, data probably corrupt Oct 17 12:20:37 router2 kernel: [ 38.621029] SQUASHFS error: squashfs_read_data failed to read block 0x23686e Oct 17 12:20:37 router2 kernel: [ 38.628199] SQUASHFS error: Unable to read fragment cache entry [23686e] Oct 17 12:20:37 router2 kernel: [ 38.635010] SQUASHFS error: Unable to read page, block 23686e, size 16b28 The filesystem problem would leave some random file damaged, so different services would fail. Over time, the router became less and less functional as various files became inaccessible and after a few cycles, wouldn't boot at all. I wondered if there was a problem with my old configuration on the new release (though I'm not sure how that could damage the squashfs), so I reinstalled a few more times in different ways, e.g., doing a factory install (openwrt-21.02.0-ath79-generic-wd_mynet-n750-squashfs-factory.bin and then the upgrade) instead of just the upgrade, and configuring from scratch rather than from the backup. But each time I had the same problem with the router. It wasn't the same block on different installs, I noticed, but it seemed to be consistent for a particular installation attempt. Oct 17 16:11:14 router2 kernel: [ 53.182571] SQUASHFS error: xz decompression failed, data probably corrupt Oct 17 16:11:14 router2 kernel: [ 53.189582] SQUASHFS error: squashfs_read_data failed to read block 0x21e9e6 Oct 17 16:11:14 router2 kernel: [ 53.196749] SQUASHFS error: Unable to read fragment cache entry [21e9e6] Oct 17 16:11:14 router2 kernel: [ 53.203559] SQUASHFS error: Unable to read page, block 21e9e6, size fd9c Once there were two blocks (I think this is a reboot of the install above): Oct 17 16:29:04 router2 kernel: [ 78.505075] SQUASHFS error: xz decompression failed, data probably corrupt Oct 17 16:29:04 router2 kernel: [ 78.512103] SQUASHFS error: squashfs_read_data failed to read block 0x1e6e76 Oct 17 16:29:05 router2 kernel: [ 79.111366] SQUASHFS error: xz decompression failed, data probably corrupt Oct 17 16:29:05 router2 kernel: [ 79.118386] SQUASHFS error: squashfs_read_data failed to read block 0x21e9e6 Oct 17 16:29:05 router2 kernel: [ 79.125565] SQUASHFS error: Unable to read fragment cache entry [21e9e6] Oct 17 16:29:05 router2 kernel: [ 79.132445] SQUASHFS error: Unable to read page, block 21e9e6, size fd9c One time there was first a jffs error, followed by lots of squashfs errors. Sorry, I don't have the log for that one. I now realize that I should have tried power cycling a clean install a few times to see if there were errors right away or if they only happened after files were installed/changed. To check whether the router was just having a hardware problem, I reinstalled openwrt-19.07.8 and configured it the same. I have not seen any errors after a few power cycles, which points to a problem with the new release. I did not see any bug reports on this tracker that mention squashfs problems and googling, I did not find any useful discussions, hence this bug report. I guess it could be that the new release uses a bad bit of memory that the earlier release managed to miss. I looked for but didn't find a memory test utility, so I don't know how to examine that possibility. Though the fact that it was different blocks each time makes it not sound like a hardware problem.

So I gave up running OpenWrt on this device and returned it to factory firmware.

However today I've noticed the following commit in OpenWrt master:

https://git.openwrt.org/?p=openwrt/openwrt.git;a=commit;h=540377010532d9840ebe0778c2af991bd4b67052

So I did a new build and after 4 hours of uptime the issue has not appeared yet. So hopefully the above commit fixed the issue!