60af8a6a7a
- Use proper synhronization primitives to protect the internal fdesc node cache used in fdescfs. - Properly initialize and uninitalize hash. - Remove unused functions. Since fdescfs might recurse on itself, adding proper locking to it needed some tricky workarounds in some parts to make it work. For instance, a descriptor in fdescfs could refer to an open descriptor to itself, thus forcing the thread to recurse on vnode locks. Because of this, other race conditions also had to be fixed. Tested by: pho Reviewed by: kib (mentor) Approved by: kib (mentor)
70 lines
2.5 KiB
C
70 lines
2.5 KiB
C
/*-
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* Copyright (c) 1992, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software donated to Berkeley by
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* Jan-Simon Pendry.
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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, this list of conditions and the following 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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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)fdesc.h 8.5 (Berkeley) 1/21/94
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*
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* $FreeBSD$
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*/
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#ifdef _KERNEL
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/* Private mount flags for fdescfs. */
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#define FMNT_UNMOUNTF 0x01
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struct fdescmount {
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struct vnode *f_root; /* Root node */
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int flags;
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};
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#define FD_ROOT 1
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#define FD_DESC 3
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typedef enum {
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Froot,
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Fdesc
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} fdntype;
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struct fdescnode {
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LIST_ENTRY(fdescnode) fd_hash; /* Hash list */
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struct vnode *fd_vnode; /* Back ptr to vnode */
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fdntype fd_type; /* Type of this node */
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unsigned fd_fd; /* Fd to be dup'ed */
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int fd_ix; /* filesystem index */
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};
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extern struct mtx fdesc_hashmtx;
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#define VFSTOFDESC(mp) ((struct fdescmount *)((mp)->mnt_data))
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#define VTOFDESC(vp) ((struct fdescnode *)(vp)->v_data)
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extern vfs_init_t fdesc_init;
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extern vfs_uninit_t fdesc_uninit;
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extern int fdesc_allocvp(fdntype, unsigned, int, struct mount *,
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struct vnode **, struct thread *);
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#endif /* _KERNEL */
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