xref: /linux/fs/9p/v9fs_vfs.h (revision a4ff64edf9edc8f05e2183610dc8306d3279c6ac)
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 struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode,
44 			     dev_t rdev);
45 int v9fs_init_inode(struct v9fs_session_info *v9ses,
46 		    struct inode *inode, umode_t mode, dev_t rdev);
47 void v9fs_evict_inode(struct inode *inode);
48 ino_t v9fs_qid2ino(struct p9_qid *qid);
49 void v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
50 		      struct super_block *sb, unsigned int flags);
51 void v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode,
52 			   unsigned int flags);
53 int v9fs_dir_release(struct inode *inode, struct file *filp);
54 int v9fs_file_open(struct inode *inode, struct file *file);
55 int v9fs_uflags2omode(int uflags, int extended);
56 
57 void v9fs_blank_wstat(struct p9_wstat *wstat);
58 int v9fs_vfs_setattr_dotl(struct mnt_idmap *idmap,
59 			  struct dentry *dentry, struct iattr *iattr);
60 int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
61 			 int datasync);
62 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode);
63 int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode);
64 static inline void v9fs_invalidate_inode_attr(struct inode *inode)
65 {
66 	struct v9fs_inode *v9inode;
67 
68 	v9inode = V9FS_I(inode);
69 	v9inode->cache_validity |= V9FS_INO_INVALID_ATTR;
70 }
71 
72 int v9fs_open_to_dotl_flags(int flags);
73 
74 static inline void v9fs_i_size_write(struct inode *inode, loff_t i_size)
75 {
76 	/*
77 	 * 32-bit need the lock, concurrent updates could break the
78 	 * sequences and make i_size_read() loop forever.
79 	 * 64-bit updates are atomic and can skip the locking.
80 	 */
81 	if (sizeof(i_size) > sizeof(long))
82 		spin_lock(&inode->i_lock);
83 	i_size_write(inode, i_size);
84 	if (sizeof(i_size) > sizeof(long))
85 		spin_unlock(&inode->i_lock);
86 }
87 #endif
88