[PATCH] lockdep: annotate the sysfs i_mutex to be a separate class (232ba9db) · Commits · 戴 / test

sysfs has a different i_mutex lock order behavior for i_mutex than the other filesystems; sysfs i_mutex is called in many places with subsystem locks held. At the same time, many of the VFS locking rules do not apply to sysfs at all (cross directory rename for example). To untangle this mess (which gives false positives in lockdep), we're giving sysfs inodes their own class for i_mutex. Signed-off-by:

Arjan van de Ven <arjan@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Greg KH <greg@kroah.com> Signed-off-by:

Andrew Morton <akpm@osdl.org> Signed-off-by:

Linus Torvalds <torvalds@osdl.org>

fs/sysfs/inode.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -109,6 +109,17 @@ static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
		inode->i_ctime = iattr->ia_ctime;
		}


		/*
		* sysfs has a different i_mutex lock order behavior for i_mutex than other
		* filesystems; sysfs i_mutex is called in many places with subsystem locks
		* held. At the same time, many of the VFS locking rules do not apply to
		* sysfs at all (cross directory rename for example). To untangle this mess
		* (which gives false positives in lockdep), we're giving sysfs inodes their
		* own class for i_mutex.
		*/
		static struct lock_class_key sysfs_inode_imutex_key;

		struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent * sd)
		{
		struct inode * inode = new_inode(sysfs_sb);
		@@ -118,6 +129,7 @@ struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent * sd)
		inode->i_mapping->a_ops = &sysfs_aops;
		inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
		inode->i_op = &sysfs_inode_operations;
		lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key);

		if (sd->s_iattr) {
		/* sysfs_dirent has non-default attributes

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