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7bcd74b98d
Some features can only work when all layers are on the same fs. Test this condition during mount time, so features can check them later. Add helper ovl_same_sb() to return the common super block in case all layers are on the same fs. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
59 lines
1.4 KiB
C
59 lines
1.4 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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};
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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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struct dentry *workdir;
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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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wait_queue_head_t copyup_wq;
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/* sb common to all layers */
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struct super_block *same_sb;
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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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struct dentry *__upperdentry;
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struct ovl_dir_cache *cache;
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union {
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struct {
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u64 version;
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const char *redirect;
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bool opaque;
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bool copying;
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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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static inline struct dentry *ovl_upperdentry_dereference(struct ovl_entry *oe)
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{
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return lockless_dereference(oe->__upperdentry);
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}
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