PROBLEM: mounting affs over loop hangs in syscall (x86 only?)

From: Bernardo Innocenti (bernie@codewiz.org)
Date: Mon Dec 18 2000 - 16:53:19 EST


[1.] One line summary of the problem:
mounting affs over loop hangs in syscall (x86 only?)

[2.] Full description of the problem/report:
Mounting a valid Amiga Fast File System hard disk image used
to work fine even on x86 (endianity discords with m68k) back
in 2.2.x.

On 2.4.0-test11 (and possibily previous versions as well), this
command hangs forever:

 mount -t affs -o loop work.img /mnt

The mount process hangs in uninterruptable syscall:

 # ps ax | grep mount
 3904 pts/4 DL 0:00 mount -t affs -o loop work.img /mnt

Reading directly from /proc/3904/stat:

3904 (mount) D 1398 3904 1398 34820 3904 256 16 0 119 0 0 5 0 \
0 9 0 0 0 43136018 1396736 341 4294967295 134512640 134568236 \
3221223064 3221222424 1074833310 524294 2147220207 0 0 \
3222489067 0 0 17 0

After this, other program can still do open("work.img" ,"r"), but
UAE hanged like mount when accessing the file (perhaps it tried
an mmap() on it?):

 # ps ax | grep uae
 8048 pts/1 D 0:00 ./uae

I recall trying to mount an affs image some months ago (2.3.xx) and
having the very same problem, so it's not a recently introduced bug.

[3.] Keywords (i.e., modules, networking, kernel):
kernel, filesystems, amiga, affs, loop, mount, partition

[4.] Kernel version (from /proc/version):
Linux version 2.4.0-test12 (root@beetle) (gcc version 2.96 20000731 \
(Red Hat Linux 7.0)) #2 Wed Dec 13 00:24:27 CET 2000

[5.] Output of Oops.. message
No OOPSes are printed, no useful debug messages appear in
dmesg output.

[6.] A small shell script or example program which triggers the
     problem (if possible)

 Get an Amiga Fast File System image. If you don't have one handy,
you can create a file of a few MBs and use UAE to format it.
Amiga floppy disk images (.adf files) might trigger the problem
too (untested).

 Then use this command to mount it:

 mount -t affs -o loop my_amiga_hd.img /mnt

[7.] Environment
[7.1.] Software (add the output of the ver_linux script here)
mount: mount-2.10r

[7.2.] Processor information (from /proc/cpuinfo):
processor : 0
vendor_id : AuthenticAMD
cpu family : 6
model : 2
model name : AMD Athlon(tm) Processor
stepping : 1
cpu MHz : 700.050
cache size : 512 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 1
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat pse36 mmx fxsr syscall mmxext 3dnowext 3dnow
bogomips : 1395.92

[7.3.] Module information (from /proc/modules):
affs 31472 1
loop 7840 2
emu10k1 43456 1
soundcore 3824 4 [emu10k1]
r128 147920 1
vmnet 18240 3
vmmon 18480 0
ipt_REJECT 2080 6 (autoclean)
iptable_filter 1824 0 (autoclean) (unused)
ip_nat_ftp 3184 0 (unused)
ip_conntrack_ftp 2016 0 (unused)
iptable_nat 12864 1 [ip_nat_ftp]
ip_conntrack 12800 2 [ip_nat_ftp ip_conntrack_ftp iptable_nat]
ip_tables 10304 5 [ipt_REJECT iptable_filter iptable_nat]
8139too 15392 1
agpgart 13328 3
af_packet 11200 2 (autoclean)
ppp_async 6352 1
ppp_generic 12928 3 [ppp_async]
slhc 5040 0 [ppp_generic]
autofs4 9824 2
ne2k-pci 4672 1 (autoclean)
8390 6080 0 (autoclean) [ne2k-pci]
nls_iso8859-1 2880 1 (autoclean)
nls_cp437 4384 1 (autoclean)
vfat 11408 1 (autoclean)
fat 31264 0 (autoclean) [vfat]

[7.4.] Loaded driver and hardware information (/proc/ioports, /proc/iomem)
not relevant

[7.5.] PCI information ('lspci -vvv' as root)
not relevant

[7.6.] SCSI information (from /proc/scsi/scsi)
not relevant

[7.7.] Other information that might be relevant to the problem
no mount points are added to /proc/mounts before the syscall
hangs.

NOTE: when replying to this message, please also Cc: to me,
as I'm not subscribed to this mailing list.

ALSO NOTE: I'm willing to cooperate with whoever wants to
fix this bug. I'll give all the assistance I can, including
running debug versions of kernel modules, providing the
FFS images that trigger the problem and giving shell access
to my system for deeper inspection.

-- 
  // Bernardo Innocenti
\X/  http://www.codewiz.org
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This archive was generated by hypermail 2b29 : Sat Dec 23 2000 - 21:00:23 EST