Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6

[pandora-kernel.git] / fs / sysfs / inode.c

diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
index 5e0e31c..e79e38d 100644 (file)
--- a/fs/sysfs/inode.c
+++ b/fs/sysfs/inode.c
@@ -12,6 +12,7 @@
 #include <linux/namei.h>
 #include <linux/backing-dev.h>
 #include <linux/capability.h>
+#include <linux/errno.h>
 #include "sysfs.h"
 
 extern struct super_block * sysfs_sb;
@@ -109,15 +110,26 @@ 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);
        if (inode) {
-               inode->i_blksize = PAGE_CACHE_SIZE;
                inode->i_blocks = 0;
                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
@@ -222,17 +234,18 @@ void sysfs_drop_dentry(struct sysfs_dirent * sd, struct dentry * parent)
        }
 }
 
-void sysfs_hash_and_remove(struct dentry * dir, const char * name)
+int sysfs_hash_and_remove(struct dentry * dir, const char * name)
 {
        struct sysfs_dirent * sd;
        struct sysfs_dirent * parent_sd;
+       int found = 0;
 
        if (!dir)
-               return;
+               return -ENOENT;
 
        if (dir->d_inode == NULL)
                /* no inode means this hasn't been made visible yet */
-               return;
+               return -ENOENT;
 
        parent_sd = dir->d_fsdata;
        mutex_lock(&dir->d_inode->i_mutex);
@@ -243,8 +256,11 @@ void sysfs_hash_and_remove(struct dentry * dir, const char * name)
                        list_del_init(&sd->s_sibling);
                        sysfs_drop_dentry(sd, dir);
                        sysfs_put(sd);
+                       found = 1;
                        break;
                }
        }
        mutex_unlock(&dir->d_inode->i_mutex);
+
+       return found ? 0 : -ENOENT;
 }