From: Thomas Gleixner Date: Tue, 29 Nov 2005 15:57:17 +0000 (+0100) Subject: [JFFS2] Fix the slab cache constructor of 'struct jffs2_inode_info' objects. X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=21eeb7aa116b1f59fc23339521173cbb13e57f1a;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git [JFFS2] Fix the slab cache constructor of 'struct jffs2_inode_info' objects. JFFS2 initialize f->sem mutex as "locked" in the slab constructor which is a bug. Objects are freed with unlocked f->sem mutex. So, when they allocated again, f->sem is unlocked because the slab cache constructor is not called for them. The constructor is called only once when memory pages are allocated for objects (namely, when the slab layer allocates new slabs). So, sometimes 'struct jffs2_inode_info' are allocated with unlocked f->sem, sometimes with locked. This is a bug. Instead, initialize f->sem as unlocked in the constructor. I.e., in the "constructed" state f->sem must be unlocked. From: Keijiro Yano Acked-by: Artem B. Bityutskiy Signed-off-by: Thomas Gleixner --- diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c index 543420665c5..d0fcc5f3497 100644 --- a/fs/jffs2/fs.c +++ b/fs/jffs2/fs.c @@ -234,6 +234,7 @@ void jffs2_read_inode (struct inode *inode) c = JFFS2_SB_INFO(inode->i_sb); jffs2_init_inode_info(f); + down(&f->sem); ret = jffs2_do_read_inode(c, f, inode->i_ino, &latest_node); @@ -400,6 +401,7 @@ struct inode *jffs2_new_inode (struct inode *dir_i, int mode, struct jffs2_raw_i f = JFFS2_INODE_INFO(inode); jffs2_init_inode_info(f); + down(&f->sem); memset(ri, 0, sizeof(*ri)); /* Set OS-specific defaults for new inodes */ diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c index 9e0b5458d9c..93883817cbd 100644 --- a/fs/jffs2/super.c +++ b/fs/jffs2/super.c @@ -51,7 +51,7 @@ static void jffs2_i_init_once(void * foo, kmem_cache_t * cachep, unsigned long f if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == SLAB_CTOR_CONSTRUCTOR) { - init_MUTEX_LOCKED(&ei->sem); + init_MUTEX(&ei->sem); inode_init_once(&ei->vfs_inode); } }