Bug#292318: kernel-image-2.6.10-1-686: Disappearing header line in /proc/swaps
Package: kernel-image-2.6.10-1-686
Version: 2.6.10-3
Severity: minor
The file /proc/swaps normally contains a header line reading something
like
"Filename\t\t\t\tType\t\tSize\tUsed\tPriority\n"
at least that's how it appears to be generated in mm/swapfile.c. I just
had a situation where this header line went missing, breaking dynswap (a
dynamic swap manager designed to replace swapd).
The scenario went as follows. In the /proc/swaps dumps I trimmed some
whitespace for legibility and line length.
- started out with a swapless system (with /proc/swaps completely empty)
- added n swap files (with swapon(file, 0))
- removed the most recent n-2 swapfiles in LIFO order (using swapoff())
- removed the original swapfile
- left with only the second swapfile, /proc/swaps now read:
/var/tmp/dynswap/2 file 320544 10112 -2
- note missing header line!
- after "swapoff /var/tmp/dynswap/2", /proc/swaps was (properly) empty
- then, after "swapon /var/tmp/dynswap/2", it was back to normal:
Filename Type Size Used
Priority/var/tmp/dynswap/2 file 320544 0 -18
I can reproduce the scenario with a minimum of 3 swapfiles, i.e. n=3:
- swapon 1
- swapon 2
- swapon 3
- swapoff 3
- swapoff 1
- cat /proc/swaps -> missing header!
-- System Information:
Debian Release: 3.1
APT prefers testing
APT policy: (500, 'testing'), (50, 'unstable')
Architecture: i386 (i686)
Kernel: Linux 2.6.10-1-686
Locale: LANG=en_US, LC_CTYPE=en_US (charmap=ISO-8859-1)
Versions of packages kernel-image-2.6.10-1-686 depends on:
ii coreutils [fileutils] 5.2.1-2 The GNU core utilities
ii initrd-tools 0.1.76 tools to create initrd image
for p
ii module-init-tools 3.1-rel-2 tools for managing Linux
kernel mo
-- no debconf information
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