Revision 5c81a4197de38411fe3e27f8593fff73a5d6b868 authored by Arjan van de Ven on 03 July 2006, 07:25:20 UTC, committed by Linus Torvalds on 03 July 2006, 22:27:08 UTC
The quota code plays interesting games with the lock ordering; to quote Jan: | i_mutex of inode containing quota file is acquired after all other | quota locks. i_mutex of all other inodes is acquired before quota | locks. Quota code makes sure (by resetting inode operations and | setting special flag on inode) that noone tries to enter quota code | while holding i_mutex on a quota file... The good news is that all of this special case i_mutex grabbing happens in the (per filesystem) low level quota write function. For this special case we need a new I_MUTEX_* nesting level, since this just entirely outside any of the regular VFS locking rules for i_mutex. I trust Jan on his blue eyes that this is not ever going to deadlock; and based on that the patch below is what it takes to inform lockdep of these very interesting new locking rules. The new locking rule for the I_MUTEX_QUOTA nesting level is that this is the deepest possible level of nesting for i_mutex, and that this only should be used in quota write (and possibly read) function of filesystems. This makes the lock ordering of the I_MUTEX_* levels: I_MUTEX_PARENT -> I_MUTEX_CHILD -> I_MUTEX_NORMAL -> I_MUTEX_QUOTA Has no effect on non-lockdep kernels. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Jan Kara <jack@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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arch | ||
block | ||
crypto | ||
drivers | ||
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include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
scripts | ||
security | ||
sound | ||
usr | ||
.gitignore | -rw-r--r-- | 462 bytes |
COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 87.5 KB |
Kbuild | -rw-r--r-- | 1.2 KB |
MAINTAINERS | -rw-r--r-- | 69.5 KB |
Makefile | -rw-r--r-- | 44.9 KB |
README | -rw-r--r-- | 16.2 KB |
REPORTING-BUGS | -rw-r--r-- | 3.0 KB |
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