1 #ifndef _FS_NFSD_FILECACHE_H
2 #define _FS_NFSD_FILECACHE_H
3
4 #include <linux/fsnotify_backend.h>
5
6 /*
7 * This is the fsnotify_mark container that nfsd attaches to the files that it
8 * is holding open. Note that we have a separate refcount here aside from the
9 * one in the fsnotify_mark. We only want a single fsnotify_mark attached to
10 * the inode, and for each nfsd_file to hold a reference to it.
11 *
12 * The fsnotify_mark is itself refcounted, but that's not sufficient to tell us
13 * how to put that reference. If there are still outstanding nfsd_files that
14 * reference the mark, then we would want to call fsnotify_put_mark on it.
15 * If there were not, then we'd need to call fsnotify_destroy_mark. Since we
16 * can't really tell the difference, we use the nfm_mark to keep track of how
17 * many nfsd_files hold references to the mark. When that counter goes to zero
18 * then we know to call fsnotify_destroy_mark on it.
19 */
20 struct nfsd_file_mark {
21 struct fsnotify_mark nfm_mark;
22 atomic_t nfm_ref;
23 };
24
25 /*
26 * A representation of a file that has been opened by knfsd. These are hashed
27 * in the hashtable by inode pointer value. Note that this object doesn't
28 * hold a reference to the inode by itself, so the nf_inode pointer should
29 * never be dereferenced, only used for comparison.
30 */
31 struct nfsd_file {
32 struct hlist_node nf_node;
33 struct list_head nf_lru;
34 struct rcu_head nf_rcu;
35 struct file *nf_file;
36 const struct cred *nf_cred;
37 struct net *nf_net;
38 #define NFSD_FILE_HASHED (0)
39 #define NFSD_FILE_PENDING (1)
40 #define NFSD_FILE_BREAK_READ (2)
41 #define NFSD_FILE_BREAK_WRITE (3)
42 #define NFSD_FILE_REFERENCED (4)
43 unsigned long nf_flags;
44 struct inode *nf_inode;
45 unsigned int nf_hashval;
46 atomic_t nf_ref;
47 unsigned char nf_may;
48 struct nfsd_file_mark *nf_mark;
49 };
50
51 int nfsd_file_cache_init(void);
52 void nfsd_file_cache_purge(struct net *);
53 void nfsd_file_cache_shutdown(void);
54 void nfsd_file_put(struct nfsd_file *nf);
55 struct nfsd_file *nfsd_file_get(struct nfsd_file *nf);
56 void nfsd_file_close_inode_sync(struct inode *inode);
57 bool nfsd_file_is_cached(struct inode *inode);
58 __be32 nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
59 unsigned int may_flags, struct nfsd_file **nfp);
60 int nfsd_file_cache_stats_open(struct inode *, struct file *);
61 #endif /* _FS_NFSD_FILECACHE_H */