xref: /openbmc/linux/fs/9p/v9fs_vfs.h (revision fd88d2e5)
1  /* SPDX-License-Identifier: GPL-2.0-only */
2  /*
3   * V9FS VFS extensions.
4   *
5   *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
6   *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
7   */
8  #ifndef FS_9P_V9FS_VFS_H
9  #define FS_9P_V9FS_VFS_H
10  
11  /* plan9 semantics are that created files are implicitly opened.
12   * But linux semantics are that you call create, then open.
13   * the plan9 approach is superior as it provides an atomic
14   * open.
15   * we track the create fid here. When the file is opened, if fidopen is
16   * non-zero, we use the fid and can skip some steps.
17   * there may be a better way to do this, but I don't know it.
18   * one BAD way is to clunk the fid on create, then open it again:
19   * you lose the atomicity of file open
20   */
21  
22  /* special case:
23   * unlink calls remove, which is an implicit clunk. So we have to track
24   * that kind of thing so that we don't try to clunk a dead fid.
25   */
26  #define P9_LOCK_TIMEOUT (30*HZ)
27  
28  /* flags for v9fs_stat2inode() & v9fs_stat2inode_dotl() */
29  #define V9FS_STAT2INODE_KEEP_ISIZE 1
30  
31  extern struct file_system_type v9fs_fs_type;
32  extern const struct address_space_operations v9fs_addr_operations;
33  extern const struct file_operations v9fs_file_operations;
34  extern const struct file_operations v9fs_file_operations_dotl;
35  extern const struct file_operations v9fs_dir_operations;
36  extern const struct file_operations v9fs_dir_operations_dotl;
37  extern const struct dentry_operations v9fs_dentry_operations;
38  extern const struct dentry_operations v9fs_cached_dentry_operations;
39  extern const struct file_operations v9fs_cached_file_operations;
40  extern const struct file_operations v9fs_cached_file_operations_dotl;
41  extern const struct file_operations v9fs_mmap_file_operations;
42  extern const struct file_operations v9fs_mmap_file_operations_dotl;
43  extern struct kmem_cache *v9fs_inode_cache;
44  
45  struct inode *v9fs_alloc_inode(struct super_block *sb);
46  void v9fs_free_inode(struct inode *inode);
47  struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t);
48  int v9fs_init_inode(struct v9fs_session_info *v9ses,
49  		    struct inode *inode, umode_t mode, dev_t);
50  void v9fs_evict_inode(struct inode *inode);
51  ino_t v9fs_qid2ino(struct p9_qid *qid);
52  void v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
53  		      struct super_block *sb, unsigned int flags);
54  void v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode,
55  			   unsigned int flags);
56  int v9fs_dir_release(struct inode *inode, struct file *filp);
57  int v9fs_file_open(struct inode *inode, struct file *file);
58  void v9fs_inode2stat(struct inode *inode, struct p9_wstat *stat);
59  int v9fs_uflags2omode(int uflags, int extended);
60  
61  void v9fs_blank_wstat(struct p9_wstat *wstat);
62  int v9fs_vfs_setattr_dotl(struct user_namespace *, struct dentry *,
63  			  struct iattr *);
64  int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
65  			 int datasync);
66  int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode);
67  int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode);
68  static inline void v9fs_invalidate_inode_attr(struct inode *inode)
69  {
70  	struct v9fs_inode *v9inode;
71  	v9inode = V9FS_I(inode);
72  	v9inode->cache_validity |= V9FS_INO_INVALID_ATTR;
73  	return;
74  }
75  
76  int v9fs_open_to_dotl_flags(int flags);
77  
78  static inline void v9fs_i_size_write(struct inode *inode, loff_t i_size)
79  {
80  	/*
81  	 * 32-bit need the lock, concurrent updates could break the
82  	 * sequences and make i_size_read() loop forever.
83  	 * 64-bit updates are atomic and can skip the locking.
84  	 */
85  	if (sizeof(i_size) > sizeof(long))
86  		spin_lock(&inode->i_lock);
87  	i_size_write(inode, i_size);
88  	if (sizeof(i_size) > sizeof(long))
89  		spin_unlock(&inode->i_lock);
90  }
91  #endif
92