a6b28ee02a
devices. The implementation allows read and write filters to be created and piggybacks on the poll() file operation to determine when a filter should trigger. The piggyback mechanism is simply to check for the EWOULDBLOCK or EAGAIN return code from read(), write() or ioctl() system calls and then update the kqueue() polling state bits. The implementation is similar to the one found in the cuse(3) module. Refer to sys/fs/cuse/*.[ch] for more details. MFC after: 1 week Sponsored by: Mellanox Technologies
187 lines
4.4 KiB
C
187 lines
4.4 KiB
C
/*-
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* Copyright (c) 2010 Isilon Systems, Inc.
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* Copyright (c) 2010 iX Systems, Inc.
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* Copyright (c) 2010 Panasas, Inc.
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* Copyright (c) 2013-2017 Mellanox Technologies, Ltd.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice unmodified, this list of conditions, and the following
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* disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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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 <sys/param.h>
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#include <sys/file.h>
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#include <sys/filedesc.h>
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#include <sys/refcount.h>
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#include <sys/capsicum.h>
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#include <sys/proc.h>
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#include <linux/fs.h>
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#include <linux/slab.h>
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struct linux_file;
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#undef file
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extern struct fileops linuxfileops;
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static inline struct linux_file *
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linux_fget(unsigned int fd)
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{
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cap_rights_t rights;
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struct file *file;
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if (fget_unlocked(curthread->td_proc->p_fd, fd,
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cap_rights_init(&rights), &file, NULL) != 0) {
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return (NULL);
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}
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return (struct linux_file *)file->f_data;
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}
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extern void linux_file_free(struct linux_file *filp);
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static inline void
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fput(struct linux_file *filp)
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{
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if (refcount_release(filp->_file == NULL ?
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&filp->f_count : &filp->_file->f_count)) {
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linux_file_free(filp);
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}
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}
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static inline unsigned int
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file_count(struct linux_file *filp)
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{
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return (filp->_file == NULL ?
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filp->f_count : filp->_file->f_count);
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}
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static inline void
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put_unused_fd(unsigned int fd)
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{
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cap_rights_t rights;
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struct file *file;
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if (fget_unlocked(curthread->td_proc->p_fd, fd,
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cap_rights_init(&rights), &file, NULL) != 0) {
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return;
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}
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/*
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* NOTE: We should only get here when the "fd" has not been
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* installed, so no need to free the associated Linux file
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* structure.
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*/
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fdclose(curthread, file, fd);
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/* drop extra reference */
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fdrop(file, curthread);
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}
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static inline void
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fd_install(unsigned int fd, struct linux_file *filp)
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{
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cap_rights_t rights;
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struct file *file;
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if (fget_unlocked(curthread->td_proc->p_fd, fd,
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cap_rights_init(&rights), &file, NULL) != 0) {
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filp->_file = NULL;
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} else {
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filp->_file = file;
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finit(file, filp->f_mode, DTYPE_DEV, filp, &linuxfileops);
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/* transfer reference count from "filp" to "file" */
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while (refcount_release(&filp->f_count) == 0)
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refcount_acquire(&file->f_count);
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}
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/* drop the extra reference */
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fput(filp);
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}
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static inline int
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get_unused_fd(void)
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{
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struct file *file;
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int error;
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int fd;
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error = falloc(curthread, &file, &fd, 0);
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if (error)
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return -error;
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/* drop the extra reference */
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fdrop(file, curthread);
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return fd;
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}
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static inline int
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get_unused_fd_flags(int flags)
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{
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struct file *file;
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int error;
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int fd;
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error = falloc(curthread, &file, &fd, flags);
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if (error)
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return -error;
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/* drop the extra reference */
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fdrop(file, curthread);
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return fd;
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}
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extern struct linux_file *linux_file_alloc(void);
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static inline struct linux_file *
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alloc_file(int mode, const struct file_operations *fops)
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{
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struct linux_file *filp;
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filp = linux_file_alloc();
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filp->f_op = fops;
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filp->f_mode = mode;
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return (filp);
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}
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struct fd {
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struct linux_file *linux_file;
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};
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static inline void fdput(struct fd fd)
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{
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fput(fd.linux_file);
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}
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static inline struct fd fdget(unsigned int fd)
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{
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struct linux_file *f = linux_fget(fd);
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return (struct fd){f};
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}
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#define file linux_file
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#define fget(...) linux_fget(__VA_ARGS__)
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#endif /* _LINUX_FILE_H_ */
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