mount_ext2fs now lets me mount the filesystem ro, and everything seems to work fine.
However, I am now unable to mount the filesystem r/w, however the output I receive seems to indicate that this is the intended behavior.
copying relevant chat messages
16:39 <@tuxillo> try a r/w mount and see what it says
16:42 <@tuxillo> skylrhawk: write anything you need in privmsg
16:46 < skylrhawk> tuxillo: uploading dmsg to pastebin
16:47 < robg> how did you mount the filesystem skylrhawk?
16:48 < skylrhawk> ---> mount_ext2fs /dev/da0s7 /mnt
16:48 < skylrhawk> dmesg --> http://pastebin.com/R8W5VLDc
16:48 < skylrhawk> last line is generated from me trying to mount it
17:02 <@swildner> skylrhawk: so yeah, what it says
17:03 <@swildner> #define EXT2_FEATURE_RO_COMPAT_SUPP EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER
17:03 <@swildner> i think with this, we only support r/o mounting
17:11 < skylrhawk> but the bug I submitted was that it was giving me kernel panic on mount, and previously it let me mount r/w, but now I am unable to mount r/w and for r/o, everything goes smoothly
17:11 < skylrhawk> so I think that's a fair solution
17:12 <@swildner> hmm?
17:12 < skylrhawk> well, to correct myself, it would let me mount, but not do file ops
17:12 < skylrhawk> http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff/5f4f1383e0706850f4d42e49fc37813cf7943539
17:12 <@swildner> it let you mount r/w before?
17:12 < skylrhawk> didn't seem to care
17:12 < skylrhawk> but then again, I couldn't touch it
17:12 < skylrhawk> so...
17:13 <@swildner> was the fs created with the sparse superblock feature?
17:14 < skylrhawk> I don't actually know
17:14 <@swildner> (note i have no clue about ext2, so my questions about it might sound dumb)
17:14 <@swildner> ok
17:14 < skylrhawk> created in obsd using newfs.ext2 /dev/sdaj
17:14 < skylrhawk> so default as far as I know
17:15 <@swildner> does "file - </dev/da0s7" show it?
17:17 < skylrhawk> "/dev/stdin: Linux rev 1.0 ext2 filesystem data, UUID=blahblahbla (large files)"
17:20 <@swildner> hm large files.. maybe i'm reading the code wrong and large files is what it doesn't like for r/w
17:20 <@swildner> not sure
17:21 <@swildner> weird though it would survive the mount before tuxillo's change
17:21 < skylrhawk> I don't really know either
17:37 <@vsrinivas> our ext2 works okay if no fancy features are used.
17:37 <@vsrinivas> (no dir_index, sparse super, etc...)
17:38 <@swildner> he has "large files" and it will mount r/o only
17:38 <@vsrinivas> :(
17:38 <@vsrinivas> ok, largefiles should've worked.
17:38 <@swildner> really
17:38 <@vsrinivas> think so....
17:38 < skylrhawk> ┐( ̄ー ̄)┌
17:39 <@vsrinivas> but no other new feature bits must have been on.
17:40 <@vsrinivas> dumpe2fs /dev/whatever | grep 'Filesystem features'
17:43 < skylrhawk> I only get one line: "Filesystem features: large_file"
17:43 <@swildner> ok
17:45 <@vsrinivas> hmm. weird, i think that should work, gonna try something w/ it. (thanks!)