msdos FS bug

Phillip R. Jaenke (
Mon, 6 Jul 1998 13:35:42 -0400 (EDT)

Found it. Found the bloody bug.

Tested on 2.1.98.

Symptoms: "Attempt to access beyond end of FAT"-type errors from MS-DOS
partitions, hard locks without logs following those error messages,
unexplained hard locks, random appearances of Sig11 and Sig4.

Problem: msdosfs is not handling a corrupted filesystem gracefully, and
causing some serious problems in the process.

Severity: If the partition is corrupted, WTF haven't you fixed it yet? ;P
This problem should NOT exist, because you shouldn't mount a corrupted fs.

Suggested Solution: Change "03:01"-style errors to "/dev/hda"-style. Add
one line reading "It is suggested you unmount this filesystem now."

Existing Workaround: UNMOUNT THE PARTITION, *DUH!* :)

It's not something that belongs at the top of the priority list, not by a
longshot. The conditions causing this problem to show simply should not
exist. However, they do here, so I managed to find it. Unmounting the
corrupted fs WILL fix the problems.

Now, to call up Maxtor, and scream for a few hours.

--Phillip R. Jaenke ( - InterNIC: PRJ5)
TheGuyInCharge(tm), Ketyra Designs, Inc.
"That's IT! I'm gonna slap Dr.Watson with a malpractice suit!!" --Keihra
ObBob! KHpB lWulH EO m23 C(PEW) B-18 OlO LM(p) ScjnM T++ A9! H8oc b123 D+
! I reserve the right to bill spammers for my time and disk space !

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