5383f45db3
commit3382290ed2upstream. [ Note, this is a Git cherry-pick of the following commit:506458efaf("locking/barriers: Convert users of lockless_dereference() to READ_ONCE()") ... for easier x86 PTI code testing and back-porting. ] READ_ONCE() now has an implicit smp_read_barrier_depends() call, so it can be used instead of lockless_dereference() without any change in semantics. Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1508840570-22169-4-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
82 lines
1.9 KiB
C
82 lines
1.9 KiB
C
/*
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*
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* Copyright (C) 2011 Novell Inc.
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* Copyright (C) 2016 Red Hat, Inc.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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struct ovl_config {
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char *lowerdir;
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char *upperdir;
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char *workdir;
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bool default_permissions;
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bool redirect_dir;
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bool index;
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};
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/* private information held for overlayfs's superblock */
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struct ovl_fs {
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struct vfsmount *upper_mnt;
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unsigned numlower;
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struct vfsmount **lower_mnt;
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/* workbasedir is the path at workdir= mount option */
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struct dentry *workbasedir;
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/* workdir is the 'work' directory under workbasedir */
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struct dentry *workdir;
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/* index directory listing overlay inodes by origin file handle */
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struct dentry *indexdir;
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long namelen;
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/* pathnames of lower and upper dirs, for show_options */
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struct ovl_config config;
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/* creds of process who forced instantiation of super block */
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const struct cred *creator_cred;
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bool tmpfile;
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bool noxattr;
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/* sb common to all layers */
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struct super_block *same_sb;
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/* Did we take the inuse lock? */
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bool upperdir_locked;
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bool workdir_locked;
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};
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/* private information held for every overlayfs dentry */
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struct ovl_entry {
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union {
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struct {
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unsigned long has_upper;
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bool opaque;
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};
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struct rcu_head rcu;
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};
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unsigned numlower;
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struct path lowerstack[];
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};
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struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
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struct ovl_inode {
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struct ovl_dir_cache *cache;
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const char *redirect;
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u64 version;
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unsigned long flags;
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struct inode vfs_inode;
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struct dentry *__upperdentry;
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struct inode *lower;
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/* synchronize copy up and more */
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struct mutex lock;
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};
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static inline struct ovl_inode *OVL_I(struct inode *inode)
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{
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return container_of(inode, struct ovl_inode, vfs_inode);
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}
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static inline struct dentry *ovl_upperdentry_dereference(struct ovl_inode *oi)
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{
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return READ_ONCE(oi->__upperdentry);
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}
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