forked from luck/tmp_suning_uos_patched
b04a23421b
Pull overlayfs updates from Miklos Szeredi: - Report constant st_ino values across copy-up even if underlying layers are on different filesystems, but using different st_dev values for each layer. Ideally we'd report the same st_dev across the overlay, and it's possible to do for filesystems that use only 32bits for st_ino by unifying the inum space. It would be nice if it wasn't a choice of 32 or 64, rather filesystems could report their current maximum (that could change on resize, so it wouldn't be set in stone). - miscellaneus fixes and a cleanup of ovl_fill_super(), that was long overdue. - created a path_put_init() helper that clears out the pointers after putting the ref. I think this could be useful elsewhere, so added it to <linux/path.h> * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (30 commits) ovl: remove unneeded arg from ovl_verify_origin() ovl: Put upperdentry if ovl_check_origin() fails ovl: rename ufs to ofs ovl: clean up getting lower layers ovl: clean up workdir creation ovl: clean up getting upper layer ovl: move ovl_get_workdir() and ovl_get_lower_layers() ovl: reduce the number of arguments for ovl_workdir_create() ovl: change order of setup in ovl_fill_super() ovl: factor out ovl_free_fs() helper ovl: grab reference to workbasedir early ovl: split out ovl_get_indexdir() from ovl_fill_super() ovl: split out ovl_get_lower_layers() from ovl_fill_super() ovl: split out ovl_get_workdir() from ovl_fill_super() ovl: split out ovl_get_upper() from ovl_fill_super() ovl: split out ovl_get_lowerstack() from ovl_fill_super() ovl: split out ovl_get_workpath() from ovl_fill_super() ovl: split out ovl_get_upperpath() from ovl_fill_super() ovl: use path_put_init() in error paths for ovl_fill_super() vfs: add path_put_init() ...
92 lines
2.1 KiB
C
92 lines
2.1 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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struct ovl_layer {
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struct vfsmount *mnt;
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dev_t pseudo_dev;
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};
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struct ovl_path {
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struct ovl_layer *layer;
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struct dentry *dentry;
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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 ovl_layer *lower_layers;
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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 ovl_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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