94 lines
2.2 KiB
C
94 lines
2.2 KiB
C
/*
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* descriptor table internals; you almost certainly want file.h instead.
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*/
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#ifndef __LINUX_FDTABLE_H
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#define __LINUX_FDTABLE_H
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//#include <linux/posix_types.h>
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#include <linux/compiler.h>
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#include <linux/spinlock.h>
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//#include <linux/rcupdate.h>
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#include <linux/types.h>
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//#include <linux/init.h>
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#include <linux/fs.h>
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#include <linux/atomic.h>
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/*
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* The default fd array needs to be at least BITS_PER_LONG,
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* as this is the granularity returned by copy_fdset().
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*/
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#define NR_OPEN_DEFAULT BITS_PER_LONG
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struct fdtable {
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unsigned int max_fds;
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struct file __rcu **fd; /* current fd array */
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// unsigned long *close_on_exec;
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unsigned long *open_fds;
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unsigned long *full_fds_bits;
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// struct rcu_head rcu;
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};
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#if 0
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static inline bool close_on_exec(unsigned int fd, const struct fdtable *fdt)
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{
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return test_bit(fd, fdt->close_on_exec);
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}
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static inline bool fd_is_open(unsigned int fd, const struct fdtable *fdt)
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{
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return test_bit(fd, fdt->open_fds);
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}
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#endif
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/*
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* Open file table structure
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*/
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struct files_struct {
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/*
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* read mostly part
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*/
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atomic_t count;
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//bool resize_in_progress;
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//wait_queue_head_t resize_wait;
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struct fdtable __rcu *fdt;
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struct fdtable fdtab;
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/*
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* written part on a separate cache line in SMP
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*/
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spinlock_t file_lock;
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//spinlock_t file_lock ____cacheline_aligned_in_smp;
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unsigned int next_fd;
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unsigned long close_on_exec_init[1];
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unsigned long open_fds_init[1];
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unsigned long full_fds_bits_init[1];
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struct file __rcu *fd_array[NR_OPEN_DEFAULT];
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};
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extern int __alloc_fd(struct files_struct *files,
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unsigned int start, unsigned int end, unsigned int flags);
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extern void __fd_install(struct files_struct *files,
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unsigned int fd, struct file *file);
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extern int __close_fd(unsigned int fd);
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//extern struct kmem_cache *files_cachep;
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/*
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* The caller must ensure that fd table isn't shared or hold rcu or file lock
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*/
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static inline struct file *__fcheck_files(struct files_struct *files, unsigned int fd)
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{
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struct fdtable *fdt = files->fdt; //rcu_dereference_raw(files->fdt);
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if (fd < fdt->max_fds)
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return fdt->fd[fd];
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return NULL;
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}
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static inline struct file *fcheck_files(struct files_struct *files, unsigned int fd)
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{
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return __fcheck_files(files, fd);
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}
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#endif /* __LINUX_FDTABLE_H */
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