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authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /include/linux/fdtable.h
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'include/linux/fdtable.h')
-rw-r--r--include/linux/fdtable.h130
1 files changed, 130 insertions, 0 deletions
diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
new file mode 100644
index 00000000..158a41ee
--- /dev/null
+++ b/include/linux/fdtable.h
@@ -0,0 +1,130 @@
+/*
+ * descriptor table internals; you almost certainly want file.h instead.
+ */
+
+#ifndef __LINUX_FDTABLE_H
+#define __LINUX_FDTABLE_H
+
+#include <linux/posix_types.h>
+#include <linux/compiler.h>
+#include <linux/spinlock.h>
+#include <linux/rcupdate.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+
+#include <linux/atomic.h>
+
+/*
+ * The default fd array needs to be at least BITS_PER_LONG,
+ * as this is the granularity returned by copy_fdset().
+ */
+#define NR_OPEN_DEFAULT BITS_PER_LONG
+
+struct fdtable {
+ unsigned int max_fds;
+ struct file __rcu **fd; /* current fd array */
+ unsigned long *close_on_exec;
+ unsigned long *open_fds;
+ struct rcu_head rcu;
+ struct fdtable *next;
+};
+
+static inline void __set_close_on_exec(int fd, struct fdtable *fdt)
+{
+ __set_bit(fd, fdt->close_on_exec);
+}
+
+static inline void __clear_close_on_exec(int fd, struct fdtable *fdt)
+{
+ __clear_bit(fd, fdt->close_on_exec);
+}
+
+static inline bool close_on_exec(int fd, const struct fdtable *fdt)
+{
+ return test_bit(fd, fdt->close_on_exec);
+}
+
+static inline void __set_open_fd(int fd, struct fdtable *fdt)
+{
+ __set_bit(fd, fdt->open_fds);
+}
+
+static inline void __clear_open_fd(int fd, struct fdtable *fdt)
+{
+ __clear_bit(fd, fdt->open_fds);
+}
+
+static inline bool fd_is_open(int fd, const struct fdtable *fdt)
+{
+ return test_bit(fd, fdt->open_fds);
+}
+
+/*
+ * Open file table structure
+ */
+struct files_struct {
+ /*
+ * read mostly part
+ */
+ atomic_t count;
+ struct fdtable __rcu *fdt;
+ struct fdtable fdtab;
+ /*
+ * written part on a separate cache line in SMP
+ */
+ spinlock_t file_lock ____cacheline_aligned_in_smp;
+ int next_fd;
+ unsigned long close_on_exec_init[1];
+ unsigned long open_fds_init[1];
+ struct file __rcu * fd_array[NR_OPEN_DEFAULT];
+};
+
+#define rcu_dereference_check_fdtable(files, fdtfd) \
+ (rcu_dereference_check((fdtfd), \
+ lockdep_is_held(&(files)->file_lock) || \
+ atomic_read(&(files)->count) == 1 || \
+ rcu_my_thread_group_empty()))
+
+#define files_fdtable(files) \
+ (rcu_dereference_check_fdtable((files), (files)->fdt))
+
+struct file_operations;
+struct vfsmount;
+struct dentry;
+
+extern int expand_files(struct files_struct *, int nr);
+extern void free_fdtable_rcu(struct rcu_head *rcu);
+extern void __init files_defer_init(void);
+
+static inline void free_fdtable(struct fdtable *fdt)
+{
+ call_rcu(&fdt->rcu, free_fdtable_rcu);
+}
+
+static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd)
+{
+ struct file * file = NULL;
+ struct fdtable *fdt = files_fdtable(files);
+
+ if (fd < fdt->max_fds)
+ file = rcu_dereference_check_fdtable(files, fdt->fd[fd]);
+ return file;
+}
+
+/*
+ * Check whether the specified fd has an open file.
+ */
+#define fcheck(fd) fcheck_files(current->files, fd)
+
+struct task_struct;
+
+struct files_struct *get_files_struct(struct task_struct *);
+void put_files_struct(struct files_struct *fs);
+void reset_files_struct(struct files_struct *);
+int unshare_files(struct files_struct **);
+struct files_struct *dup_fd(struct files_struct *, int *);
+
+extern struct kmem_cache *files_cachep;
+
+#endif /* __LINUX_FDTABLE_H */