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 refcount_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 rhlist_head nf_rlist;
33 void *nf_inode;
34 struct file *nf_file;
35 const struct cred *nf_cred;
36 struct net *nf_net;
37 #define NFSD_FILE_HASHED (0)
38 #define NFSD_FILE_PENDING (1)
39 #define NFSD_FILE_REFERENCED (2)
40 #define NFSD_FILE_GC (3)
41 unsigned long nf_flags;
42 refcount_t nf_ref;
43 unsigned char nf_may;
44
45 struct nfsd_file_mark *nf_mark;
46 struct list_head nf_lru;
47 struct rcu_head nf_rcu;
48 ktime_t nf_birthtime;
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 int nfsd_file_cache_start_net(struct net *net);
55 void nfsd_file_cache_shutdown_net(struct net *net);
56 void nfsd_file_put(struct nfsd_file *nf);
57 struct nfsd_file *nfsd_file_get(struct nfsd_file *nf);
58 void nfsd_file_close_inode_sync(struct inode *inode);
59 void nfsd_file_net_dispose(struct nfsd_net *nn);
60 bool nfsd_file_is_cached(struct inode *inode);
61 __be32 nfsd_file_acquire_gc(struct svc_rqst *rqstp, struct svc_fh *fhp,
62 unsigned int may_flags, struct nfsd_file **nfp);
63 __be32 nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
64 unsigned int may_flags, struct nfsd_file **nfp);
65 __be32 nfsd_file_acquire_opened(struct svc_rqst *rqstp, struct svc_fh *fhp,
66 unsigned int may_flags, struct file *file,
67 struct nfsd_file **nfp);
68 int nfsd_file_cache_stats_show(struct seq_file *m, void *v);
69 #endif /* _FS_NFSD_FILECACHE_H */
70
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