Problem: df on tmpfs not reported correctly when filesystem is full
From: Emil Natan
Date: Thu May 19 2011 - 06:16:07 EST
Hi,
The problem seems to have been introduced in version linux-2.6.36 and up, it works well in 2.6.35.13. When tmpfs filesystem is full, in the output of df command the "Used", "Available" and "Use%" the numbers are replaced with hyphens:
# df /images/1
Filesystem 1K-blocks Used Available Use% Mounted on
tmpfs 1024 - - - /images/1
Here is how it looks with "good" and "bad" kernel and how to reproduce the issue. Please let me know if more debug information is needed in a mail cc-ied directly to me.
bad: kernel version 2.6.36.4
# ./kernels/linux-2.6.36.4/scripts/ver_linux
If some fields are empty or look unusual you may have an old version.
Compare to the current minimal requirements in Documentation/Changes.
Linux xxx 2.6.36.4 #1 SMP Wed May 18 16:52:45 IDT 2011 i686 GNU/Linux
Gnu C 4.4.5
Gnu make 3.81
binutils 2.20.1
util-linux 2.17.2
mount support
module-init-tools 3.12
e2fsprogs 1.41.12
Linux C Library 2.11.2
Dynamic linker (ldd) 2.11.2
Procps 3.2.8
Net-tools 1.60
Kbd 1.15.2
Sh-utils 8.5
Modules Loaded ipmi_devintf ipmi_si ipmi_msghandler ipv6 loop hpwdt pcspkr psmouse joydev evdev serio_raw ext3 jbd mbcache sg sr_mod cdrom usbhid uhci_hcd ata_piix libata ehci_hcd hpsa scsi_mod usbcore bnx2 cciss
# mount -t tmpfs -o size=1m tmpfs /images/1
# dd if=/dev/zero of=/images/1/file bs=1k count=1017
1017+0 records in
1017+0 records out
1041408 bytes (1.0 MB) copied, 0.00164136 s, 634 MB/s
# df /images/1
Filesystem 1K-blocks Used Available Use% Mounted on
tmpfs 1024 - - - /images/1
# > /images/1/file
# df /images/1
Filesystem 1K-blocks Used Available Use% Mounted on
tmpfs 1024 0 1024 0% /images/1
# dd if=/dev/zero of=/images/1/file bs=1k count=500
500+0 records in
500+0 records out
512000 bytes (512 kB) copied, 0.000784176 s, 653 MB/s
# df /images/1
Filesystem 1K-blocks Used Available Use% Mounted on
tmpfs 1024 508 516 50% /images/1
good: kervel version 2.6.35.13
#./linux-2.6.35.13/scripts/ver_linux
If some fields are empty or look unusual you may have an old version.
Compare to the current minimal requirements in Documentation/Changes.
Linux xxx 2.6.35.13 #1 SMP Wed May 18 17:07:00 IDT 2011 i686 GNU/Linux
Gnu C 4.4.5
Gnu make 3.81
binutils 2.20.1
util-linux 2.17.2
mount support
module-init-tools 3.12
e2fsprogs 1.41.12
Linux C Library 2.11.2
Dynamic linker (ldd) 2.11.2
Procps 3.2.8
Net-tools 1.60
Kbd 1.15.2
Sh-utils 8.5
Modules Loaded ipmi_devintf ipmi_si ipmi_msghandler ipv6 loop pcspkr hpwdt psmouse serio_raw joydev evdev ext3 jbd mbcache sg sr_mod cdrom usbhid ata_piix libata hpsa uhci_hcd scsi_mod ehci_hcd usbcore bnx2 cciss
#mount -t tmpfs -o size=1m tmpfs /images/1
#dd if=/dev/zero of=/images/1/file bs=1k count=1017
dd: writing `/images/1/file': No space left on device
1017+0 records in
1016+0 records out
1040384 bytes (1.0 MB) copied, 0.00173007 s, 601 MB/s
#df /images/1
Filesystem 1K-blocks Used Available Use% Mounted on
tmpfs 1024 1024 0 100% /images/1
Regards,
--
Emil Natan
Technical Officer
Israel Internet Association (ISOC-IL)
Phone: +972 3 9700900
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/