xref: /linux/fs/9p/v9fs_vfs.h (revision 1bc18858358d7a4e263a63b59a12cbfd25c16670)
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 /**
32  * struct v9fs_dentry - v9fs specific dentry data
33  * @head: List of fid associated with this dentry
34  * @expire_time: Lookup cache expiration time for negative dentries
35  * @rcu: used by kfree_rcu to schedule clean up job
36  */
37 struct v9fs_dentry {
38 	struct hlist_head head;
39 	u64 expire_time;
40 	struct rcu_head rcu;
41 };
42 #define to_v9fs_dentry(d) ((struct v9fs_dentry *)((d)->d_fsdata))
43 
44 extern struct file_system_type v9fs_fs_type;
45 extern const struct address_space_operations v9fs_addr_operations;
46 extern const struct file_operations v9fs_file_operations;
47 extern const struct file_operations v9fs_file_operations_dotl;
48 extern const struct file_operations v9fs_dir_operations;
49 extern const struct file_operations v9fs_dir_operations_dotl;
50 extern const struct dentry_operations v9fs_dentry_operations;
51 extern void v9fs_ndentry_refresh_timeout(struct dentry *dentry);
52 extern void v9fs_dentry_fid_remove(struct dentry *dentry);
53 extern const struct dentry_operations v9fs_cached_dentry_operations;
54 extern struct kmem_cache *v9fs_inode_cache;
55 
56 struct inode *v9fs_alloc_inode(struct super_block *sb);
57 void v9fs_free_inode(struct inode *inode);
58 void v9fs_set_netfs_context(struct inode *inode);
59 int v9fs_init_inode(struct v9fs_session_info *v9ses,
60 		    struct inode *inode, umode_t mode, dev_t rdev);
61 void v9fs_evict_inode(struct inode *inode);
62 #if (BITS_PER_LONG == 32)
63 #define QID2INO(q) ((ino_t) (((q)->path+2) ^ (((q)->path) >> 32)))
64 #else
65 #define QID2INO(q) ((ino_t) ((q)->path+2))
66 #endif
67 
68 void v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
69 		      struct super_block *sb, unsigned int flags);
70 void v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode,
71 			   unsigned int flags);
72 int v9fs_dir_release(struct inode *inode, struct file *filp);
73 int v9fs_file_open(struct inode *inode, struct file *file);
74 int v9fs_uflags2omode(int uflags, int extended);
75 
76 void v9fs_blank_wstat(struct p9_wstat *wstat);
77 int v9fs_vfs_setattr_dotl(struct mnt_idmap *idmap,
78 			  struct dentry *dentry, struct iattr *iattr);
79 int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
80 			 int datasync);
81 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode);
82 int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode);
83 static inline void v9fs_invalidate_inode_attr(struct inode *inode)
84 {
85 	struct v9fs_inode *v9inode;
86 
87 	v9inode = V9FS_I(inode);
88 	v9inode->cache_validity |= V9FS_INO_INVALID_ATTR;
89 }
90 
91 int v9fs_open_to_dotl_flags(int flags);
92 
93 #endif
94