[PATCH] lockdep: annotate the sysfs i_mutex to be a separate class

232ba9db · Arjan van de Ven <[email protected]> · 2006-07-12 09:03:06 -07:00

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 <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Greg KH <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Commit: 232ba9dbd68bb084d5d90c511f207d18eae614da
Parents: d579091b

Changes

1 files changed · +12 −0

File	Status	Add	Del	Content
fs/sysfs/inode.c	modified	+12	−0	View file

fs/sysfs/inode.c

View file

diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
index 5e0e31c..9889e54 100644
--- a/fs/sysfs/inode.c
+++ b/fs/sysfs/inode.c
@@ -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