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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /include/linux/fdtable.h | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (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.h | 130 |
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 */ |