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https://github.com/brain-hackers/linux-brain.git
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091141a42e
Some uses cases repeatedly get and put references to the same file, but the only exposed interface is doing these one at the time. As each of these entail an atomic inc or dec on a shared structure, that cost can add up. Add fget_many(), which works just like fget(), except it takes an argument for how many references to get on the file. Ditto fput_many(), which can drop an arbitrary number of references to a file. Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
95 lines
2.2 KiB
C
95 lines
2.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Wrapper functions for accessing the file_struct fd array.
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*/
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#ifndef __LINUX_FILE_H
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#define __LINUX_FILE_H
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#include <linux/compiler.h>
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#include <linux/types.h>
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#include <linux/posix_types.h>
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struct file;
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extern void fput(struct file *);
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extern void fput_many(struct file *, unsigned int);
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struct file_operations;
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struct vfsmount;
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struct dentry;
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struct inode;
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struct path;
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extern struct file *alloc_file_pseudo(struct inode *, struct vfsmount *,
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const char *, int flags, const struct file_operations *);
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extern struct file *alloc_file_clone(struct file *, int flags,
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const struct file_operations *);
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static inline void fput_light(struct file *file, int fput_needed)
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{
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if (fput_needed)
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fput(file);
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}
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struct fd {
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struct file *file;
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unsigned int flags;
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};
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#define FDPUT_FPUT 1
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#define FDPUT_POS_UNLOCK 2
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static inline void fdput(struct fd fd)
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{
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if (fd.flags & FDPUT_FPUT)
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fput(fd.file);
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}
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extern struct file *fget(unsigned int fd);
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extern struct file *fget_many(unsigned int fd, unsigned int refs);
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extern struct file *fget_raw(unsigned int fd);
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extern unsigned long __fdget(unsigned int fd);
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extern unsigned long __fdget_raw(unsigned int fd);
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extern unsigned long __fdget_pos(unsigned int fd);
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extern void __f_unlock_pos(struct file *);
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static inline struct fd __to_fd(unsigned long v)
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{
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return (struct fd){(struct file *)(v & ~3),v & 3};
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}
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static inline struct fd fdget(unsigned int fd)
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{
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return __to_fd(__fdget(fd));
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}
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static inline struct fd fdget_raw(unsigned int fd)
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{
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return __to_fd(__fdget_raw(fd));
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}
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static inline struct fd fdget_pos(int fd)
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{
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return __to_fd(__fdget_pos(fd));
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}
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static inline void fdput_pos(struct fd f)
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{
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if (f.flags & FDPUT_POS_UNLOCK)
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__f_unlock_pos(f.file);
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fdput(f);
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}
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extern int f_dupfd(unsigned int from, struct file *file, unsigned flags);
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extern int replace_fd(unsigned fd, struct file *file, unsigned flags);
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extern void set_close_on_exec(unsigned int fd, int flag);
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extern bool get_close_on_exec(unsigned int fd);
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extern int get_unused_fd_flags(unsigned flags);
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extern void put_unused_fd(unsigned int fd);
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extern void fd_install(unsigned int fd, struct file *file);
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extern void flush_delayed_fput(void);
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extern void __fput_sync(struct file *);
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#endif /* __LINUX_FILE_H */
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