xref: /linux/fs/9p/v9fs_vfs.h (revision cfee1b50775869de9076d021ea11a8438854dcba)
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 struct kmem_cache *v9fs_inode_cache;
40 
41 struct inode *v9fs_alloc_inode(struct super_block *sb);
42 void v9fs_free_inode(struct inode *inode);
43 void v9fs_set_netfs_context(struct inode *inode);
44 int v9fs_init_inode(struct v9fs_session_info *v9ses,
45 		    struct inode *inode, struct p9_qid *qid, umode_t mode, dev_t rdev);
46 void v9fs_evict_inode(struct inode *inode);
47 #if (BITS_PER_LONG == 32)
48 #define QID2INO(q) ((ino_t) (((q)->path+2) ^ (((q)->path) >> 32)))
49 #else
50 #define QID2INO(q) ((ino_t) ((q)->path+2))
51 #endif
52 
53 void v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
54 		      struct super_block *sb, unsigned int flags);
55 void v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode,
56 			   unsigned int flags);
57 int v9fs_dir_release(struct inode *inode, struct file *filp);
58 int v9fs_file_open(struct inode *inode, struct file *file);
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 mnt_idmap *idmap,
63 			  struct dentry *dentry, struct iattr *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 
72 	v9inode = V9FS_I(inode);
73 	v9inode->cache_validity |= V9FS_INO_INVALID_ATTR;
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