1 /* 2 * Copyright 2016 Jakub Klama <jceel@FreeBSD.org> 3 * All rights reserved 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted providing that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 16 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 18 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 22 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 23 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 24 * POSSIBILITY OF SUCH DAMAGE. 25 * 26 */ 27 28 #ifndef LIB9P_FID_H 29 #define LIB9P_FID_H 30 31 #include <stdbool.h> 32 33 /* 34 * Data structure for a fid. All active fids in one session 35 * are stored in a hash table; the hash table provides the 36 * iterator to process them. (See also l9p_connection in lib9p.h.) 37 * 38 * The back-end code has additional data per fid, found via 39 * lo_aux. Currently this is allocated with a separate calloc(). 40 * 41 * Most fids represent a file or directory, but a few are special 42 * purpose, including the auth fid from Tauth+Tattach, and the 43 * fids used for extended attributes. We have our own set of 44 * flags here in lo_flags. 45 * 46 * Note that all new fids start as potentially-valid (reserving 47 * their 32-bit fid value), but not actually-valid. If another 48 * (threaded) op is invoked on a not-yet-valid fid, the fid cannot 49 * be used. A fid can also be locked against other threads, in 50 * which case they must wait for it: this happens during create 51 * and open, which on success result in the fid changing from a 52 * directory to a file. (At least, all this applies in principle 53 * -- we're currently single-threaded per connection so the locks 54 * are nop-ed out and the valid bit is mainly just for debug.) 55 * 56 * Fids that are "open" (the underlying file or directory is open) 57 * are marked as well. 58 * 59 * Locking is managed by the front end (request.c); validation 60 * and type-marking can be done by either side as needed. 61 * 62 * Fid types and validity are manipulated by set* and unset* 63 * functions, and tested by is* ops. Note that we only 64 * distinguish between "directory" and "not directory" at this 65 * level, i.e., symlinks and devices are just "not a directory 66 * fid". Also, fids cannot be unset as auth or xattr fids, 67 * nor can an open fid become closed, except by being clunked. 68 * While files should not normally become directories, it IS normal 69 * for directory fids to become file fids due to Twalk operations. 70 * 71 * (These accessor functions are just to leave wiggle room for 72 * different future implementations.) 73 */ 74 struct l9p_fid { 75 void *lo_aux; 76 uint32_t lo_fid; 77 uint32_t lo_flags; /* volatile atomic_t when threaded? */ 78 }; 79 80 enum l9p_lo_flags { 81 L9P_LO_ISAUTH = 0x01, 82 L9P_LO_ISDIR = 0x02, 83 L9P_LO_ISOPEN = 0x04, 84 L9P_LO_ISVALID = 0x08, 85 L9P_LO_ISXATTR = 0x10, 86 }; 87 88 static inline bool 89 l9p_fid_isauth(struct l9p_fid *fid) 90 { 91 return ((fid->lo_flags & L9P_LO_ISAUTH) != 0); 92 } 93 94 static inline void 95 l9p_fid_setauth(struct l9p_fid *fid) 96 { 97 fid->lo_flags |= L9P_LO_ISAUTH; 98 } 99 100 static inline bool 101 l9p_fid_isdir(struct l9p_fid *fid) 102 { 103 return ((fid->lo_flags & L9P_LO_ISDIR) != 0); 104 } 105 106 static inline void 107 l9p_fid_setdir(struct l9p_fid *fid) 108 { 109 fid->lo_flags |= L9P_LO_ISDIR; 110 } 111 112 static inline void 113 l9p_fid_unsetdir(struct l9p_fid *fid) 114 { 115 fid->lo_flags &= ~(uint32_t)L9P_LO_ISDIR; 116 } 117 118 static inline bool 119 l9p_fid_isopen(struct l9p_fid *fid) 120 { 121 return ((fid->lo_flags & L9P_LO_ISOPEN) != 0); 122 } 123 124 static inline void 125 l9p_fid_setopen(struct l9p_fid *fid) 126 { 127 fid->lo_flags |= L9P_LO_ISOPEN; 128 } 129 130 static inline bool 131 l9p_fid_isvalid(struct l9p_fid *fid) 132 { 133 return ((fid->lo_flags & L9P_LO_ISVALID) != 0); 134 } 135 136 static inline void 137 l9p_fid_setvalid(struct l9p_fid *fid) 138 { 139 fid->lo_flags |= L9P_LO_ISVALID; 140 } 141 142 static inline void 143 l9p_fid_unsetvalid(struct l9p_fid *fid) 144 { 145 fid->lo_flags &= ~(uint32_t)L9P_LO_ISVALID; 146 } 147 148 static inline bool 149 l9p_fid_isxattr(struct l9p_fid *fid) 150 { 151 return ((fid->lo_flags & L9P_LO_ISXATTR) != 0); 152 } 153 154 static inline void 155 l9p_fid_setxattr(struct l9p_fid *fid) 156 { 157 fid->lo_flags |= L9P_LO_ISXATTR; 158 } 159 160 #endif /* LIB9P_FID_H */ 161