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-rw-r--r--fs/nfsd/filecache.h61
1 files changed, 61 insertions, 0 deletions
diff --git a/fs/nfsd/filecache.h b/fs/nfsd/filecache.h
new file mode 100644
index 000000000000..851d9abf54c2
--- /dev/null
+++ b/fs/nfsd/filecache.h
@@ -0,0 +1,61 @@
+#ifndef _FS_NFSD_FILECACHE_H
+#define _FS_NFSD_FILECACHE_H
+
+#include <linux/fsnotify_backend.h>
+
+/*
+ * This is the fsnotify_mark container that nfsd attaches to the files that it
+ * is holding open. Note that we have a separate refcount here aside from the
+ * one in the fsnotify_mark. We only want a single fsnotify_mark attached to
+ * the inode, and for each nfsd_file to hold a reference to it.
+ *
+ * The fsnotify_mark is itself refcounted, but that's not sufficient to tell us
+ * how to put that reference. If there are still outstanding nfsd_files that
+ * reference the mark, then we would want to call fsnotify_put_mark on it.
+ * If there were not, then we'd need to call fsnotify_destroy_mark. Since we
+ * can't really tell the difference, we use the nfm_mark to keep track of how
+ * many nfsd_files hold references to the mark. When that counter goes to zero
+ * then we know to call fsnotify_destroy_mark on it.
+ */
+struct nfsd_file_mark {
+ struct fsnotify_mark nfm_mark;
+ atomic_t nfm_ref;
+};
+
+/*
+ * A representation of a file that has been opened by knfsd. These are hashed
+ * in the hashtable by inode pointer value. Note that this object doesn't
+ * hold a reference to the inode by itself, so the nf_inode pointer should
+ * never be dereferenced, only used for comparison.
+ */
+struct nfsd_file {
+ struct hlist_node nf_node;
+ struct list_head nf_lru;
+ struct rcu_head nf_rcu;
+ struct file *nf_file;
+ const struct cred *nf_cred;
+ struct net *nf_net;
+#define NFSD_FILE_HASHED (0)
+#define NFSD_FILE_PENDING (1)
+#define NFSD_FILE_BREAK_READ (2)
+#define NFSD_FILE_BREAK_WRITE (3)
+#define NFSD_FILE_REFERENCED (4)
+ unsigned long nf_flags;
+ struct inode *nf_inode;
+ unsigned int nf_hashval;
+ atomic_t nf_ref;
+ unsigned char nf_may;
+ struct nfsd_file_mark *nf_mark;
+};
+
+int nfsd_file_cache_init(void);
+void nfsd_file_cache_purge(struct net *);
+void nfsd_file_cache_shutdown(void);
+void nfsd_file_put(struct nfsd_file *nf);
+struct nfsd_file *nfsd_file_get(struct nfsd_file *nf);
+void nfsd_file_close_inode_sync(struct inode *inode);
+bool nfsd_file_is_cached(struct inode *inode);
+__be32 nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
+ unsigned int may_flags, struct nfsd_file **nfp);
+int nfsd_file_cache_stats_open(struct inode *, struct file *);
+#endif /* _FS_NFSD_FILECACHE_H */