[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [Bug 1599539] Re: 2.6.0: vvfat driver generates bad FAT ent
From: |
felix |
Subject: |
[Qemu-devel] [Bug 1599539] Re: 2.6.0: vvfat driver generates bad FAT entries |
Date: |
Sat, 19 Aug 2017 15:01:37 -0000 |
I believe commits f82d92bb028a1d674bab4ccc7e6cde6c04956230 and
6817efea3a0d1bf87be815970cdb014c5a64b628 have fixed this particular bug;
although I've since noticed the vvfat driver remains quite fragile,
especially FAT32 and writing support. I've got some patches for it of my
own, which I might submit someday (they aren't quite ready yet).
Also, after some testing, it turns one can simply grow the fixed-size
root directory table above 512 entries, and it doesn't seem to actually
cause any problems after all; although I haven't tested any extreme
cases or obscure implementations. Shrinking it (entry-wise) should be
fine in any case: 1440 KiB floppy disks typically allow 224 root
directory entries, which is 14 clusters = 14 sectors.
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1599539
Title:
2.6.0: vvfat driver generates bad FAT entries
Status in QEMU:
New
Bug description:
The vvfat driver sometimes generates entries about which file system
checking utilities generate complaints.
For example, dosfsck will complain that the volume label entry has
non-zero size. ScanDisk from Windows 9x complains about invalid dot
(".") and dot-dot ("..") entries in directories and also about invalid
long file name entries. MS-DOS ScanDisk also often manages to find
"lost clusters" on the drive.
Tangentially: qemu-img convert fat:test test.img doesn't seem to work
-- it generates an 504MiB of zero bytes and hangs. qemu-img map
fat:test generates an assertion failure. Having qemu-img working might
have helped with debugging the above issue.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1599539/+subscriptions
- [Qemu-devel] [Bug 1599539] Re: 2.6.0: vvfat driver generates bad FAT entries,
felix <=