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| author | Dave Hansen <haveblue@us.ibm.com> | 2008-02-15 14:38:01 -0800 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2008-04-19 00:29:28 -0400 |
| commit | ad775f5a8faa5845377f093ca11caf577404add9 (patch) | |
| tree | f124ff1038672b8d2ef004d75c844f740d8fe52b /lib | |
| parent | 2e4b7fcd926006531935a4c79a5e9349fe51125b (diff) | |
| download | linux-stable-ad775f5a8faa5845377f093ca11caf577404add9.tar.gz linux-stable-ad775f5a8faa5845377f093ca11caf577404add9.tar.bz2 linux-stable-ad775f5a8faa5845377f093ca11caf577404add9.zip | |
[PATCH] r/o bind mounts: debugging for missed calls
There have been a few oopses caused by 'struct file's with NULL f_vfsmnts.
There was also a set of potentially missed mnt_want_write()s from
dentry_open() calls.
This patch provides a very simple debugging framework to catch these kinds of
bugs. It will WARN_ON() them, but should stop us from having any oopses or
mnt_writer count imbalances.
I'm quite convinced that this is a good thing because it found bugs in the
stuff I was working on as soon as I wrote it.
[hch: made it conditional on a debug option.
But it's still a little bit too ugly]
[hch: merged forced remount r/o fix from Dave and akpm's fix for the fix]
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 95de3102bc87..623ef24c2381 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -427,6 +427,16 @@ config DEBUG_VM If unsure, say N. +config DEBUG_WRITECOUNT + bool "Debug filesystem writers count" + depends on DEBUG_KERNEL + help + Enable this to catch wrong use of the writers count in struct + vfsmount. This will increase the size of each file struct by + 32 bits. + + If unsure, say N. + config DEBUG_LIST bool "Debug linked list manipulation" depends on DEBUG_KERNEL |