Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 1 | /* |
| 2 | URL: svn://svnanon.samba.org/samba/branches/SAMBA_4_0/source/lib/tdb/common |
| 3 | Rev: 23590 |
| 4 | Last Changed Date: 2007-06-22 13:36:10 -0400 (Fri, 22 Jun 2007) |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 5 | */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 6 | /* |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 7 | trivial database library - standalone version |
| 8 | |
| 9 | Copyright (C) Andrew Tridgell 1999-2005 |
| 10 | Copyright (C) Jeremy Allison 2000-2006 |
| 11 | Copyright (C) Paul `Rusty' Russell 2000 |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 12 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 13 | ** NOTE! The following LGPL license applies to the tdb |
| 14 | ** library. This does NOT imply that all of Samba is released |
| 15 | ** under the LGPL |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 16 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 17 | This library is free software; you can redistribute it and/or |
| 18 | modify it under the terms of the GNU Lesser General Public |
| 19 | License as published by the Free Software Foundation; either |
| 20 | version 2 of the License, or (at your option) any later version. |
| 21 | |
| 22 | This library is distributed in the hope that it will be useful, |
| 23 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 24 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 25 | Lesser General Public License for more details. |
| 26 | |
| 27 | You should have received a copy of the GNU Lesser General Public |
| 28 | License along with this library; if not, write to the Free Software |
| 29 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 30 | */ |
| 31 | |
| 32 | #ifdef CONFIG_STAND_ALONE |
| 33 | #define HAVE_MMAP |
| 34 | #define HAVE_STRDUP |
| 35 | #define HAVE_SYS_MMAN_H |
| 36 | #define HAVE_UTIME_H |
| 37 | #define HAVE_UTIME |
| 38 | #endif |
Theodore Ts'o | ebabf2a | 2008-07-13 15:32:37 -0400 | [diff] [blame] | 39 | #define _XOPEN_SOURCE 600 |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 40 | |
Theodore Ts'o | d1154eb | 2011-09-18 17:34:37 -0400 | [diff] [blame] | 41 | #include "config.h" |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 42 | #include <unistd.h> |
| 43 | #include <stdio.h> |
| 44 | #include <stdlib.h> |
| 45 | #include <stdarg.h> |
| 46 | #include <stddef.h> |
| 47 | #include <errno.h> |
| 48 | #include <string.h> |
Christophe GRENIER | e7cc6f7 | 2008-02-16 12:10:56 +0100 | [diff] [blame] | 49 | #ifdef HAVE_SYS_SELECT_H |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 50 | #include <sys/select.h> |
Christophe GRENIER | e7cc6f7 | 2008-02-16 12:10:56 +0100 | [diff] [blame] | 51 | #endif |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 52 | #include <sys/time.h> |
| 53 | #include <sys/types.h> |
| 54 | #include <time.h> |
| 55 | #ifdef HAVE_UTIME_H |
| 56 | #include <utime.h> |
| 57 | #endif |
| 58 | #include <sys/stat.h> |
| 59 | #include <sys/file.h> |
| 60 | #include <fcntl.h> |
| 61 | |
| 62 | #ifdef HAVE_SYS_MMAN_H |
| 63 | #include <sys/mman.h> |
| 64 | #endif |
| 65 | |
| 66 | #ifndef MAP_FILE |
| 67 | #define MAP_FILE 0 |
| 68 | #endif |
| 69 | |
| 70 | #ifndef MAP_FAILED |
| 71 | #define MAP_FAILED ((void *)-1) |
| 72 | #endif |
| 73 | |
| 74 | #ifndef HAVE_STRDUP |
| 75 | #define strdup rep_strdup |
| 76 | static char *rep_strdup(const char *s) |
| 77 | { |
| 78 | char *ret; |
| 79 | int length; |
| 80 | if (!s) |
| 81 | return NULL; |
| 82 | |
| 83 | if (!length) |
| 84 | length = strlen(s); |
| 85 | |
| 86 | ret = malloc(length + 1); |
| 87 | if (ret) { |
| 88 | strncpy(ret, s, length); |
| 89 | ret[length] = '\0'; |
| 90 | } |
| 91 | return ret; |
| 92 | } |
| 93 | #endif |
| 94 | |
| 95 | #ifndef PRINTF_ATTRIBUTE |
| 96 | #if (__GNUC__ >= 3) && (__GNUC_MINOR__ >= 1 ) |
| 97 | /** Use gcc attribute to check printf fns. a1 is the 1-based index of |
| 98 | * the parameter containing the format, and a2 the index of the first |
| 99 | * argument. Note that some gcc 2.x versions don't handle this |
| 100 | * properly **/ |
| 101 | #define PRINTF_ATTRIBUTE(a1, a2) __attribute__ ((format (__printf__, a1, a2))) |
| 102 | #else |
| 103 | #define PRINTF_ATTRIBUTE(a1, a2) |
| 104 | #endif |
| 105 | #endif |
| 106 | |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 107 | typedef int bool; |
| 108 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 109 | #include "tdb.h" |
| 110 | |
Theodore Ts'o | d1b75fd | 2011-11-05 14:51:51 -0400 | [diff] [blame] | 111 | static TDB_DATA tdb_null; |
| 112 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 113 | #ifndef u32 |
| 114 | #define u32 unsigned |
| 115 | #endif |
| 116 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 117 | typedef u32 tdb_len_t; |
| 118 | typedef u32 tdb_off_t; |
| 119 | |
| 120 | #ifndef offsetof |
| 121 | #define offsetof(t,f) ((unsigned int)&((t *)0)->f) |
| 122 | #endif |
| 123 | |
| 124 | #define TDB_MAGIC_FOOD "TDB file\n" |
| 125 | #define TDB_VERSION (0x26011967 + 6) |
| 126 | #define TDB_MAGIC (0x26011999U) |
| 127 | #define TDB_FREE_MAGIC (~TDB_MAGIC) |
| 128 | #define TDB_DEAD_MAGIC (0xFEE1DEAD) |
| 129 | #define TDB_RECOVERY_MAGIC (0xf53bc0e7U) |
| 130 | #define TDB_ALIGNMENT 4 |
| 131 | #define MIN_REC_SIZE (2*sizeof(struct list_struct) + TDB_ALIGNMENT) |
| 132 | #define DEFAULT_HASH_SIZE 131 |
| 133 | #define FREELIST_TOP (sizeof(struct tdb_header)) |
| 134 | #define TDB_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1)) |
| 135 | #define TDB_BYTEREV(x) (((((x)&0xff)<<24)|((x)&0xFF00)<<8)|(((x)>>8)&0xFF00)|((x)>>24)) |
| 136 | #define TDB_DEAD(r) ((r)->magic == TDB_DEAD_MAGIC) |
| 137 | #define TDB_BAD_MAGIC(r) ((r)->magic != TDB_MAGIC && !TDB_DEAD(r)) |
| 138 | #define TDB_HASH_TOP(hash) (FREELIST_TOP + (BUCKET(hash)+1)*sizeof(tdb_off_t)) |
| 139 | #define TDB_HASHTABLE_SIZE(tdb) ((tdb->header.hash_size+1)*sizeof(tdb_off_t)) |
| 140 | #define TDB_DATA_START(hash_size) TDB_HASH_TOP(hash_size-1) |
| 141 | #define TDB_RECOVERY_HEAD offsetof(struct tdb_header, recovery_start) |
| 142 | #define TDB_SEQNUM_OFS offsetof(struct tdb_header, sequence_number) |
| 143 | #define TDB_PAD_BYTE 0x42 |
| 144 | #define TDB_PAD_U32 0x42424242 |
| 145 | |
| 146 | /* NB assumes there is a local variable called "tdb" that is the |
| 147 | * current context, also takes doubly-parenthesized print-style |
| 148 | * argument. */ |
| 149 | #define TDB_LOG(x) tdb->log.log_fn x |
| 150 | |
| 151 | /* lock offsets */ |
| 152 | #define GLOBAL_LOCK 0 |
| 153 | #define ACTIVE_LOCK 4 |
| 154 | #define TRANSACTION_LOCK 8 |
| 155 | |
| 156 | /* free memory if the pointer is valid and zero the pointer */ |
| 157 | #ifndef SAFE_FREE |
| 158 | #define SAFE_FREE(x) do { if ((x) != NULL) {free(x); (x)=NULL;} } while(0) |
| 159 | #endif |
| 160 | |
| 161 | #define BUCKET(hash) ((hash) % tdb->header.hash_size) |
| 162 | |
| 163 | #define DOCONV() (tdb->flags & TDB_CONVERT) |
| 164 | #define CONVERT(x) (DOCONV() ? tdb_convert(&x, sizeof(x)) : &x) |
| 165 | |
| 166 | |
| 167 | /* the body of the database is made of one list_struct for the free space |
| 168 | plus a separate data list for each hash value */ |
| 169 | struct list_struct { |
| 170 | tdb_off_t next; /* offset of the next record in the list */ |
| 171 | tdb_len_t rec_len; /* total byte length of record */ |
| 172 | tdb_len_t key_len; /* byte length of key */ |
| 173 | tdb_len_t data_len; /* byte length of data */ |
| 174 | u32 full_hash; /* the full 32 bit hash of the key */ |
| 175 | u32 magic; /* try to catch errors */ |
| 176 | /* the following union is implied: |
| 177 | union { |
| 178 | char record[rec_len]; |
| 179 | struct { |
| 180 | char key[key_len]; |
| 181 | char data[data_len]; |
| 182 | } |
| 183 | u32 totalsize; (tailer) |
| 184 | } |
| 185 | */ |
| 186 | }; |
| 187 | |
| 188 | |
| 189 | /* this is stored at the front of every database */ |
| 190 | struct tdb_header { |
| 191 | char magic_food[32]; /* for /etc/magic */ |
| 192 | u32 version; /* version of the code */ |
| 193 | u32 hash_size; /* number of hash entries */ |
| 194 | tdb_off_t rwlocks; /* obsolete - kept to detect old formats */ |
| 195 | tdb_off_t recovery_start; /* offset of transaction recovery region */ |
| 196 | tdb_off_t sequence_number; /* used when TDB_SEQNUM is set */ |
| 197 | tdb_off_t reserved[29]; |
| 198 | }; |
| 199 | |
| 200 | struct tdb_lock_type { |
| 201 | int list; |
| 202 | u32 count; |
| 203 | u32 ltype; |
| 204 | }; |
| 205 | |
| 206 | struct tdb_traverse_lock { |
| 207 | struct tdb_traverse_lock *next; |
| 208 | u32 off; |
| 209 | u32 hash; |
| 210 | int lock_rw; |
| 211 | }; |
| 212 | |
| 213 | |
| 214 | struct tdb_methods { |
| 215 | int (*tdb_read)(struct tdb_context *, tdb_off_t , void *, tdb_len_t , int ); |
| 216 | int (*tdb_write)(struct tdb_context *, tdb_off_t, const void *, tdb_len_t); |
| 217 | void (*next_hash_chain)(struct tdb_context *, u32 *); |
| 218 | int (*tdb_oob)(struct tdb_context *, tdb_off_t , int ); |
| 219 | int (*tdb_expand_file)(struct tdb_context *, tdb_off_t , tdb_off_t ); |
| 220 | int (*tdb_brlock)(struct tdb_context *, tdb_off_t , int, int, int, size_t); |
| 221 | }; |
| 222 | |
| 223 | struct tdb_context { |
| 224 | char *name; /* the name of the database */ |
| 225 | void *map_ptr; /* where it is currently mapped */ |
| 226 | int fd; /* open file descriptor for the database */ |
| 227 | tdb_len_t map_size; /* how much space has been mapped */ |
| 228 | int read_only; /* opened read-only */ |
| 229 | int traverse_read; /* read-only traversal */ |
| 230 | struct tdb_lock_type global_lock; |
| 231 | int num_lockrecs; |
| 232 | struct tdb_lock_type *lockrecs; /* only real locks, all with count>0 */ |
| 233 | enum TDB_ERROR ecode; /* error code for last tdb error */ |
| 234 | struct tdb_header header; /* a cached copy of the header */ |
| 235 | u32 flags; /* the flags passed to tdb_open */ |
| 236 | struct tdb_traverse_lock travlocks; /* current traversal locks */ |
| 237 | struct tdb_context *next; /* all tdbs to avoid multiple opens */ |
| 238 | dev_t device; /* uniquely identifies this tdb */ |
| 239 | ino_t inode; /* uniquely identifies this tdb */ |
| 240 | struct tdb_logging_context log; |
| 241 | unsigned int (*hash_fn)(TDB_DATA *key); |
| 242 | int open_flags; /* flags used in the open - needed by reopen */ |
| 243 | unsigned int num_locks; /* number of chain locks held */ |
| 244 | const struct tdb_methods *methods; |
| 245 | struct tdb_transaction *transaction; |
| 246 | int page_size; |
| 247 | int max_dead_records; |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 248 | bool have_transaction_lock; |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 249 | }; |
| 250 | |
| 251 | |
| 252 | /* |
| 253 | internal prototypes |
| 254 | */ |
| 255 | static int tdb_munmap(struct tdb_context *tdb); |
| 256 | static void tdb_mmap(struct tdb_context *tdb); |
| 257 | static int tdb_lock(struct tdb_context *tdb, int list, int ltype); |
| 258 | static int tdb_unlock(struct tdb_context *tdb, int list, int ltype); |
| 259 | static int tdb_brlock(struct tdb_context *tdb, tdb_off_t offset, int rw_type, int lck_type, int probe, size_t len); |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 260 | static int tdb_transaction_lock(struct tdb_context *tdb, int ltype); |
| 261 | static int tdb_transaction_unlock(struct tdb_context *tdb); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 262 | static int tdb_brlock_upgrade(struct tdb_context *tdb, tdb_off_t offset, size_t len); |
| 263 | static int tdb_write_lock_record(struct tdb_context *tdb, tdb_off_t off); |
| 264 | static int tdb_write_unlock_record(struct tdb_context *tdb, tdb_off_t off); |
| 265 | static int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d); |
| 266 | static int tdb_ofs_write(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d); |
| 267 | static void *tdb_convert(void *buf, u32 size); |
| 268 | static int tdb_free(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec); |
| 269 | static tdb_off_t tdb_allocate(struct tdb_context *tdb, tdb_len_t length, struct list_struct *rec); |
| 270 | static int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d); |
| 271 | static int tdb_ofs_write(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d); |
| 272 | static int tdb_lock_record(struct tdb_context *tdb, tdb_off_t off); |
| 273 | static int tdb_unlock_record(struct tdb_context *tdb, tdb_off_t off); |
| 274 | static int tdb_rec_read(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec); |
| 275 | static int tdb_rec_write(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec); |
| 276 | static int tdb_do_delete(struct tdb_context *tdb, tdb_off_t rec_ptr, struct list_struct *rec); |
| 277 | static unsigned char *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t len); |
| 278 | static int tdb_parse_data(struct tdb_context *tdb, TDB_DATA key, |
| 279 | tdb_off_t offset, tdb_len_t len, |
| 280 | int (*parser)(TDB_DATA key, TDB_DATA data, |
| 281 | void *private_data), |
| 282 | void *private_data); |
| 283 | static tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash, int locktype, |
| 284 | struct list_struct *rec); |
| 285 | static void tdb_io_init(struct tdb_context *tdb); |
| 286 | static int tdb_expand(struct tdb_context *tdb, tdb_off_t size); |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 287 | static int tdb_rec_free_read(struct tdb_context *tdb, tdb_off_t off, |
| 288 | struct list_struct *rec); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 289 | |
| 290 | |
| 291 | /* file: error.c */ |
| 292 | |
| 293 | enum TDB_ERROR tdb_error(struct tdb_context *tdb) |
| 294 | { |
| 295 | return tdb->ecode; |
| 296 | } |
| 297 | |
| 298 | static struct tdb_errname { |
| 299 | enum TDB_ERROR ecode; const char *estring; |
| 300 | } emap[] = { {TDB_SUCCESS, "Success"}, |
| 301 | {TDB_ERR_CORRUPT, "Corrupt database"}, |
| 302 | {TDB_ERR_IO, "IO Error"}, |
| 303 | {TDB_ERR_LOCK, "Locking error"}, |
| 304 | {TDB_ERR_OOM, "Out of memory"}, |
| 305 | {TDB_ERR_EXISTS, "Record exists"}, |
| 306 | {TDB_ERR_NOLOCK, "Lock exists on other keys"}, |
| 307 | {TDB_ERR_EINVAL, "Invalid parameter"}, |
| 308 | {TDB_ERR_NOEXIST, "Record does not exist"}, |
| 309 | {TDB_ERR_RDONLY, "write not permitted"} }; |
| 310 | |
| 311 | /* Error string for the last tdb error */ |
| 312 | const char *tdb_errorstr(struct tdb_context *tdb) |
| 313 | { |
| 314 | u32 i; |
| 315 | for (i = 0; i < sizeof(emap) / sizeof(struct tdb_errname); i++) |
| 316 | if (tdb->ecode == emap[i].ecode) |
| 317 | return emap[i].estring; |
| 318 | return "Invalid error code"; |
| 319 | } |
| 320 | |
| 321 | /* file: lock.c */ |
| 322 | |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 323 | #define TDB_MARK_LOCK 0x80000000 |
| 324 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 325 | /* a byte range locking function - return 0 on success |
| 326 | this functions locks/unlocks 1 byte at the specified offset. |
| 327 | |
| 328 | On error, errno is also set so that errors are passed back properly |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 329 | through tdb_open(). |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 330 | |
| 331 | note that a len of zero means lock to end of file |
| 332 | */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 333 | int tdb_brlock(struct tdb_context *tdb, tdb_off_t offset, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 334 | int rw_type, int lck_type, int probe, size_t len) |
| 335 | { |
| 336 | struct flock fl; |
| 337 | int ret; |
| 338 | |
| 339 | if (tdb->flags & TDB_NOLOCK) { |
| 340 | return 0; |
| 341 | } |
| 342 | |
| 343 | if ((rw_type == F_WRLCK) && (tdb->read_only || tdb->traverse_read)) { |
| 344 | tdb->ecode = TDB_ERR_RDONLY; |
| 345 | return -1; |
| 346 | } |
| 347 | |
| 348 | fl.l_type = rw_type; |
| 349 | fl.l_whence = SEEK_SET; |
| 350 | fl.l_start = offset; |
| 351 | fl.l_len = len; |
| 352 | fl.l_pid = 0; |
| 353 | |
| 354 | do { |
| 355 | ret = fcntl(tdb->fd,lck_type,&fl); |
| 356 | } while (ret == -1 && errno == EINTR); |
| 357 | |
| 358 | if (ret == -1) { |
| 359 | /* Generic lock error. errno set by fcntl. |
| 360 | * EAGAIN is an expected return from non-blocking |
| 361 | * locks. */ |
| 362 | if (!probe && lck_type != F_SETLK) { |
| 363 | /* Ensure error code is set for log fun to examine. */ |
| 364 | tdb->ecode = TDB_ERR_LOCK; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 365 | TDB_LOG((tdb, TDB_DEBUG_TRACE,"tdb_brlock failed (fd=%d) at offset %d rw_type=%d lck_type=%d len=%d\n", |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 366 | tdb->fd, offset, rw_type, lck_type, (int)len)); |
| 367 | } |
| 368 | return TDB_ERRCODE(TDB_ERR_LOCK, -1); |
| 369 | } |
| 370 | return 0; |
| 371 | } |
| 372 | |
| 373 | |
| 374 | /* |
| 375 | upgrade a read lock to a write lock. This needs to be handled in a |
| 376 | special way as some OSes (such as solaris) have too conservative |
| 377 | deadlock detection and claim a deadlock when progress can be |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 378 | made. For those OSes we may loop for a while. |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 379 | */ |
| 380 | int tdb_brlock_upgrade(struct tdb_context *tdb, tdb_off_t offset, size_t len) |
| 381 | { |
| 382 | int count = 1000; |
| 383 | while (count--) { |
| 384 | struct timeval tv; |
| 385 | if (tdb_brlock(tdb, offset, F_WRLCK, F_SETLKW, 1, len) == 0) { |
| 386 | return 0; |
| 387 | } |
| 388 | if (errno != EDEADLK) { |
| 389 | break; |
| 390 | } |
| 391 | /* sleep for as short a time as we can - more portable than usleep() */ |
| 392 | tv.tv_sec = 0; |
| 393 | tv.tv_usec = 1; |
| 394 | select(0, NULL, NULL, NULL, &tv); |
| 395 | } |
| 396 | TDB_LOG((tdb, TDB_DEBUG_TRACE,"tdb_brlock_upgrade failed at offset %d\n", offset)); |
| 397 | return -1; |
| 398 | } |
| 399 | |
| 400 | |
| 401 | /* lock a list in the database. list -1 is the alloc list */ |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 402 | static int _tdb_lock(struct tdb_context *tdb, int list, int ltype, int op) |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 403 | { |
| 404 | struct tdb_lock_type *new_lck; |
| 405 | int i; |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 406 | bool mark_lock = ((ltype & TDB_MARK_LOCK) == TDB_MARK_LOCK); |
| 407 | |
| 408 | ltype &= ~TDB_MARK_LOCK; |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 409 | |
| 410 | /* a global lock allows us to avoid per chain locks */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 411 | if (tdb->global_lock.count && |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 412 | (ltype == tdb->global_lock.ltype || ltype == F_RDLCK)) { |
| 413 | return 0; |
| 414 | } |
| 415 | |
| 416 | if (tdb->global_lock.count) { |
| 417 | return TDB_ERRCODE(TDB_ERR_LOCK, -1); |
| 418 | } |
| 419 | |
| 420 | if (list < -1 || list >= (int)tdb->header.hash_size) { |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 421 | TDB_LOG((tdb, TDB_DEBUG_ERROR,"tdb_lock: invalid list %d for ltype=%d\n", |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 422 | list, ltype)); |
| 423 | return -1; |
| 424 | } |
| 425 | if (tdb->flags & TDB_NOLOCK) |
| 426 | return 0; |
| 427 | |
| 428 | for (i=0; i<tdb->num_lockrecs; i++) { |
| 429 | if (tdb->lockrecs[i].list == list) { |
| 430 | if (tdb->lockrecs[i].count == 0) { |
| 431 | /* |
| 432 | * Can't happen, see tdb_unlock(). It should |
| 433 | * be an assert. |
| 434 | */ |
| 435 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_lock: " |
| 436 | "lck->count == 0 for list %d", list)); |
| 437 | } |
| 438 | /* |
| 439 | * Just increment the in-memory struct, posix locks |
| 440 | * don't stack. |
| 441 | */ |
| 442 | tdb->lockrecs[i].count++; |
| 443 | return 0; |
| 444 | } |
| 445 | } |
| 446 | |
| 447 | new_lck = (struct tdb_lock_type *)realloc( |
| 448 | tdb->lockrecs, |
| 449 | sizeof(*tdb->lockrecs) * (tdb->num_lockrecs+1)); |
| 450 | if (new_lck == NULL) { |
| 451 | errno = ENOMEM; |
| 452 | return -1; |
| 453 | } |
| 454 | tdb->lockrecs = new_lck; |
| 455 | |
| 456 | /* Since fcntl locks don't nest, we do a lock for the first one, |
| 457 | and simply bump the count for future ones */ |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 458 | if (!mark_lock && |
| 459 | tdb->methods->tdb_brlock(tdb,FREELIST_TOP+4*list, ltype, op, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 460 | 0, 1)) { |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 461 | return -1; |
| 462 | } |
| 463 | |
| 464 | tdb->num_locks++; |
| 465 | |
| 466 | tdb->lockrecs[tdb->num_lockrecs].list = list; |
| 467 | tdb->lockrecs[tdb->num_lockrecs].count = 1; |
| 468 | tdb->lockrecs[tdb->num_lockrecs].ltype = ltype; |
| 469 | tdb->num_lockrecs += 1; |
| 470 | |
| 471 | return 0; |
| 472 | } |
| 473 | |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 474 | /* lock a list in the database. list -1 is the alloc list */ |
| 475 | int tdb_lock(struct tdb_context *tdb, int list, int ltype) |
| 476 | { |
| 477 | int ret; |
| 478 | ret = _tdb_lock(tdb, list, ltype, F_SETLKW); |
| 479 | if (ret) { |
| 480 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_lock failed on list %d " |
| 481 | "ltype=%d (%s)\n", list, ltype, strerror(errno))); |
| 482 | } |
| 483 | return ret; |
| 484 | } |
| 485 | |
| 486 | /* lock a list in the database. list -1 is the alloc list. non-blocking lock */ |
| 487 | int tdb_lock_nonblock(struct tdb_context *tdb, int list, int ltype) |
| 488 | { |
| 489 | return _tdb_lock(tdb, list, ltype, F_SETLK); |
| 490 | } |
| 491 | |
| 492 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 493 | /* unlock the database: returns void because it's too late for errors. */ |
| 494 | /* changed to return int it may be interesting to know there |
| 495 | has been an error --simo */ |
| 496 | int tdb_unlock(struct tdb_context *tdb, int list, int ltype) |
| 497 | { |
| 498 | int ret = -1; |
| 499 | int i; |
| 500 | struct tdb_lock_type *lck = NULL; |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 501 | bool mark_lock = ((ltype & TDB_MARK_LOCK) == TDB_MARK_LOCK); |
| 502 | |
| 503 | ltype &= ~TDB_MARK_LOCK; |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 504 | |
| 505 | /* a global lock allows us to avoid per chain locks */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 506 | if (tdb->global_lock.count && |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 507 | (ltype == tdb->global_lock.ltype || ltype == F_RDLCK)) { |
| 508 | return 0; |
| 509 | } |
| 510 | |
| 511 | if (tdb->global_lock.count) { |
| 512 | return TDB_ERRCODE(TDB_ERR_LOCK, -1); |
| 513 | } |
| 514 | |
| 515 | if (tdb->flags & TDB_NOLOCK) |
| 516 | return 0; |
| 517 | |
| 518 | /* Sanity checks */ |
| 519 | if (list < -1 || list >= (int)tdb->header.hash_size) { |
| 520 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlock: list %d invalid (%d)\n", list, tdb->header.hash_size)); |
| 521 | return ret; |
| 522 | } |
| 523 | |
| 524 | for (i=0; i<tdb->num_lockrecs; i++) { |
| 525 | if (tdb->lockrecs[i].list == list) { |
| 526 | lck = &tdb->lockrecs[i]; |
| 527 | break; |
| 528 | } |
| 529 | } |
| 530 | |
| 531 | if ((lck == NULL) || (lck->count == 0)) { |
| 532 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlock: count is 0\n")); |
| 533 | return -1; |
| 534 | } |
| 535 | |
| 536 | if (lck->count > 1) { |
| 537 | lck->count--; |
| 538 | return 0; |
| 539 | } |
| 540 | |
| 541 | /* |
| 542 | * This lock has count==1 left, so we need to unlock it in the |
| 543 | * kernel. We don't bother with decrementing the in-memory array |
| 544 | * element, we're about to overwrite it with the last array element |
| 545 | * anyway. |
| 546 | */ |
| 547 | |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 548 | if (mark_lock) { |
| 549 | ret = 0; |
| 550 | } else { |
| 551 | ret = tdb->methods->tdb_brlock(tdb, FREELIST_TOP+4*list, F_UNLCK, |
| 552 | F_SETLKW, 0, 1); |
| 553 | } |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 554 | tdb->num_locks--; |
| 555 | |
| 556 | /* |
| 557 | * Shrink the array by overwriting the element just unlocked with the |
| 558 | * last array element. |
| 559 | */ |
| 560 | |
| 561 | if (tdb->num_lockrecs > 1) { |
| 562 | *lck = tdb->lockrecs[tdb->num_lockrecs-1]; |
| 563 | } |
| 564 | tdb->num_lockrecs -= 1; |
| 565 | |
| 566 | /* |
| 567 | * We don't bother with realloc when the array shrinks, but if we have |
| 568 | * a completely idle tdb we should get rid of the locked array. |
| 569 | */ |
| 570 | |
| 571 | if (tdb->num_lockrecs == 0) { |
| 572 | SAFE_FREE(tdb->lockrecs); |
| 573 | } |
| 574 | |
| 575 | if (ret) |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 576 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlock: An error occurred unlocking!\n")); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 577 | return ret; |
| 578 | } |
| 579 | |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 580 | /* |
| 581 | get the transaction lock |
| 582 | */ |
| 583 | int tdb_transaction_lock(struct tdb_context *tdb, int ltype) |
| 584 | { |
| 585 | if (tdb->have_transaction_lock || tdb->global_lock.count) { |
| 586 | return 0; |
| 587 | } |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 588 | if (tdb->methods->tdb_brlock(tdb, TRANSACTION_LOCK, ltype, |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 589 | F_SETLKW, 0, 1) == -1) { |
| 590 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_lock: failed to get transaction lock\n")); |
| 591 | tdb->ecode = TDB_ERR_LOCK; |
| 592 | return -1; |
| 593 | } |
| 594 | tdb->have_transaction_lock = 1; |
| 595 | return 0; |
| 596 | } |
| 597 | |
| 598 | /* |
| 599 | release the transaction lock |
| 600 | */ |
| 601 | int tdb_transaction_unlock(struct tdb_context *tdb) |
| 602 | { |
| 603 | int ret; |
| 604 | if (!tdb->have_transaction_lock) { |
| 605 | return 0; |
| 606 | } |
| 607 | ret = tdb->methods->tdb_brlock(tdb, TRANSACTION_LOCK, F_UNLCK, F_SETLKW, 0, 1); |
| 608 | if (ret == 0) { |
| 609 | tdb->have_transaction_lock = 0; |
| 610 | } |
| 611 | return ret; |
| 612 | } |
| 613 | |
| 614 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 615 | |
| 616 | |
| 617 | /* lock/unlock entire database */ |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 618 | static int _tdb_lockall(struct tdb_context *tdb, int ltype, int op) |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 619 | { |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 620 | bool mark_lock = ((ltype & TDB_MARK_LOCK) == TDB_MARK_LOCK); |
| 621 | |
| 622 | ltype &= ~TDB_MARK_LOCK; |
| 623 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 624 | /* There are no locks on read-only dbs */ |
| 625 | if (tdb->read_only || tdb->traverse_read) |
| 626 | return TDB_ERRCODE(TDB_ERR_LOCK, -1); |
| 627 | |
| 628 | if (tdb->global_lock.count && tdb->global_lock.ltype == ltype) { |
| 629 | tdb->global_lock.count++; |
| 630 | return 0; |
| 631 | } |
| 632 | |
| 633 | if (tdb->global_lock.count) { |
| 634 | /* a global lock of a different type exists */ |
| 635 | return TDB_ERRCODE(TDB_ERR_LOCK, -1); |
| 636 | } |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 637 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 638 | if (tdb->num_locks != 0) { |
| 639 | /* can't combine global and chain locks */ |
| 640 | return TDB_ERRCODE(TDB_ERR_LOCK, -1); |
| 641 | } |
| 642 | |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 643 | if (!mark_lock && |
| 644 | tdb->methods->tdb_brlock(tdb, FREELIST_TOP, ltype, op, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 645 | 0, 4*tdb->header.hash_size)) { |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 646 | if (op == F_SETLKW) { |
| 647 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_lockall failed (%s)\n", strerror(errno))); |
| 648 | } |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 649 | return -1; |
| 650 | } |
| 651 | |
| 652 | tdb->global_lock.count = 1; |
| 653 | tdb->global_lock.ltype = ltype; |
| 654 | |
| 655 | return 0; |
| 656 | } |
| 657 | |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 658 | |
| 659 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 660 | /* unlock entire db */ |
| 661 | static int _tdb_unlockall(struct tdb_context *tdb, int ltype) |
| 662 | { |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 663 | bool mark_lock = ((ltype & TDB_MARK_LOCK) == TDB_MARK_LOCK); |
| 664 | |
| 665 | ltype &= ~TDB_MARK_LOCK; |
| 666 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 667 | /* There are no locks on read-only dbs */ |
| 668 | if (tdb->read_only || tdb->traverse_read) { |
| 669 | return TDB_ERRCODE(TDB_ERR_LOCK, -1); |
| 670 | } |
| 671 | |
| 672 | if (tdb->global_lock.ltype != ltype || tdb->global_lock.count == 0) { |
| 673 | return TDB_ERRCODE(TDB_ERR_LOCK, -1); |
| 674 | } |
| 675 | |
| 676 | if (tdb->global_lock.count > 1) { |
| 677 | tdb->global_lock.count--; |
| 678 | return 0; |
| 679 | } |
| 680 | |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 681 | if (!mark_lock && |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 682 | tdb->methods->tdb_brlock(tdb, FREELIST_TOP, F_UNLCK, F_SETLKW, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 683 | 0, 4*tdb->header.hash_size)) { |
| 684 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlockall failed (%s)\n", strerror(errno))); |
| 685 | return -1; |
| 686 | } |
| 687 | |
| 688 | tdb->global_lock.count = 0; |
| 689 | tdb->global_lock.ltype = 0; |
| 690 | |
| 691 | return 0; |
| 692 | } |
| 693 | |
| 694 | /* lock entire database with write lock */ |
| 695 | int tdb_lockall(struct tdb_context *tdb) |
| 696 | { |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 697 | return _tdb_lockall(tdb, F_WRLCK, F_SETLKW); |
| 698 | } |
| 699 | |
| 700 | /* lock entire database with write lock - mark only */ |
| 701 | int tdb_lockall_mark(struct tdb_context *tdb) |
| 702 | { |
| 703 | return _tdb_lockall(tdb, F_WRLCK | TDB_MARK_LOCK, F_SETLKW); |
| 704 | } |
| 705 | |
| 706 | /* unlock entire database with write lock - unmark only */ |
| 707 | int tdb_lockall_unmark(struct tdb_context *tdb) |
| 708 | { |
| 709 | return _tdb_unlockall(tdb, F_WRLCK | TDB_MARK_LOCK); |
| 710 | } |
| 711 | |
| 712 | /* lock entire database with write lock - nonblocking varient */ |
| 713 | int tdb_lockall_nonblock(struct tdb_context *tdb) |
| 714 | { |
| 715 | return _tdb_lockall(tdb, F_WRLCK, F_SETLK); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 716 | } |
| 717 | |
| 718 | /* unlock entire database with write lock */ |
| 719 | int tdb_unlockall(struct tdb_context *tdb) |
| 720 | { |
| 721 | return _tdb_unlockall(tdb, F_WRLCK); |
| 722 | } |
| 723 | |
| 724 | /* lock entire database with read lock */ |
| 725 | int tdb_lockall_read(struct tdb_context *tdb) |
| 726 | { |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 727 | return _tdb_lockall(tdb, F_RDLCK, F_SETLKW); |
| 728 | } |
| 729 | |
| 730 | /* lock entire database with read lock - nonblock varient */ |
| 731 | int tdb_lockall_read_nonblock(struct tdb_context *tdb) |
| 732 | { |
| 733 | return _tdb_lockall(tdb, F_RDLCK, F_SETLK); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 734 | } |
| 735 | |
| 736 | /* unlock entire database with read lock */ |
| 737 | int tdb_unlockall_read(struct tdb_context *tdb) |
| 738 | { |
| 739 | return _tdb_unlockall(tdb, F_RDLCK); |
| 740 | } |
| 741 | |
| 742 | /* lock/unlock one hash chain. This is meant to be used to reduce |
| 743 | contention - it cannot guarantee how many records will be locked */ |
| 744 | int tdb_chainlock(struct tdb_context *tdb, TDB_DATA key) |
| 745 | { |
| 746 | return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK); |
| 747 | } |
| 748 | |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 749 | /* lock/unlock one hash chain, non-blocking. This is meant to be used |
| 750 | to reduce contention - it cannot guarantee how many records will be |
| 751 | locked */ |
| 752 | int tdb_chainlock_nonblock(struct tdb_context *tdb, TDB_DATA key) |
| 753 | { |
| 754 | return tdb_lock_nonblock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK); |
| 755 | } |
| 756 | |
| 757 | /* mark a chain as locked without actually locking it. Warning! use with great caution! */ |
| 758 | int tdb_chainlock_mark(struct tdb_context *tdb, TDB_DATA key) |
| 759 | { |
| 760 | return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK | TDB_MARK_LOCK); |
| 761 | } |
| 762 | |
| 763 | /* unmark a chain as locked without actually locking it. Warning! use with great caution! */ |
| 764 | int tdb_chainlock_unmark(struct tdb_context *tdb, TDB_DATA key) |
| 765 | { |
| 766 | return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK | TDB_MARK_LOCK); |
| 767 | } |
| 768 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 769 | int tdb_chainunlock(struct tdb_context *tdb, TDB_DATA key) |
| 770 | { |
| 771 | return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK); |
| 772 | } |
| 773 | |
| 774 | int tdb_chainlock_read(struct tdb_context *tdb, TDB_DATA key) |
| 775 | { |
| 776 | return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_RDLCK); |
| 777 | } |
| 778 | |
| 779 | int tdb_chainunlock_read(struct tdb_context *tdb, TDB_DATA key) |
| 780 | { |
| 781 | return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_RDLCK); |
| 782 | } |
| 783 | |
| 784 | |
| 785 | |
| 786 | /* record lock stops delete underneath */ |
| 787 | int tdb_lock_record(struct tdb_context *tdb, tdb_off_t off) |
| 788 | { |
| 789 | return off ? tdb->methods->tdb_brlock(tdb, off, F_RDLCK, F_SETLKW, 0, 1) : 0; |
| 790 | } |
| 791 | |
| 792 | /* |
| 793 | Write locks override our own fcntl readlocks, so check it here. |
| 794 | Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not |
| 795 | an error to fail to get the lock here. |
| 796 | */ |
| 797 | int tdb_write_lock_record(struct tdb_context *tdb, tdb_off_t off) |
| 798 | { |
| 799 | struct tdb_traverse_lock *i; |
| 800 | for (i = &tdb->travlocks; i; i = i->next) |
| 801 | if (i->off == off) |
| 802 | return -1; |
| 803 | return tdb->methods->tdb_brlock(tdb, off, F_WRLCK, F_SETLK, 1, 1); |
| 804 | } |
| 805 | |
| 806 | /* |
| 807 | Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not |
| 808 | an error to fail to get the lock here. |
| 809 | */ |
| 810 | int tdb_write_unlock_record(struct tdb_context *tdb, tdb_off_t off) |
| 811 | { |
| 812 | return tdb->methods->tdb_brlock(tdb, off, F_UNLCK, F_SETLK, 0, 1); |
| 813 | } |
| 814 | |
| 815 | /* fcntl locks don't stack: avoid unlocking someone else's */ |
| 816 | int tdb_unlock_record(struct tdb_context *tdb, tdb_off_t off) |
| 817 | { |
| 818 | struct tdb_traverse_lock *i; |
| 819 | u32 count = 0; |
| 820 | |
| 821 | if (off == 0) |
| 822 | return 0; |
| 823 | for (i = &tdb->travlocks; i; i = i->next) |
| 824 | if (i->off == off) |
| 825 | count++; |
| 826 | return (count == 1 ? tdb->methods->tdb_brlock(tdb, off, F_UNLCK, F_SETLKW, 0, 1) : 0); |
| 827 | } |
| 828 | |
| 829 | /* file: io.c */ |
| 830 | |
| 831 | /* check for an out of bounds access - if it is out of bounds then |
| 832 | see if the database has been expanded by someone else and expand |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 833 | if necessary |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 834 | note that "len" is the minimum length needed for the db |
| 835 | */ |
| 836 | static int tdb_oob(struct tdb_context *tdb, tdb_off_t len, int probe) |
| 837 | { |
| 838 | struct stat st; |
| 839 | if (len <= tdb->map_size) |
| 840 | return 0; |
| 841 | if (tdb->flags & TDB_INTERNAL) { |
| 842 | if (!probe) { |
| 843 | /* Ensure ecode is set for log fn. */ |
| 844 | tdb->ecode = TDB_ERR_IO; |
| 845 | TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_oob len %d beyond internal malloc size %d\n", |
| 846 | (int)len, (int)tdb->map_size)); |
| 847 | } |
| 848 | return TDB_ERRCODE(TDB_ERR_IO, -1); |
| 849 | } |
| 850 | |
| 851 | if (fstat(tdb->fd, &st) == -1) { |
| 852 | return TDB_ERRCODE(TDB_ERR_IO, -1); |
| 853 | } |
| 854 | |
| 855 | if (st.st_size < (size_t)len) { |
| 856 | if (!probe) { |
| 857 | /* Ensure ecode is set for log fn. */ |
| 858 | tdb->ecode = TDB_ERR_IO; |
| 859 | TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_oob len %d beyond eof at %d\n", |
| 860 | (int)len, (int)st.st_size)); |
| 861 | } |
| 862 | return TDB_ERRCODE(TDB_ERR_IO, -1); |
| 863 | } |
| 864 | |
| 865 | /* Unmap, update size, remap */ |
| 866 | if (tdb_munmap(tdb) == -1) |
| 867 | return TDB_ERRCODE(TDB_ERR_IO, -1); |
| 868 | tdb->map_size = st.st_size; |
| 869 | tdb_mmap(tdb); |
| 870 | return 0; |
| 871 | } |
| 872 | |
| 873 | /* write a lump of data at a specified offset */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 874 | static int tdb_write(struct tdb_context *tdb, tdb_off_t off, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 875 | const void *buf, tdb_len_t len) |
| 876 | { |
| 877 | if (len == 0) { |
| 878 | return 0; |
| 879 | } |
| 880 | |
| 881 | if (tdb->read_only || tdb->traverse_read) { |
| 882 | tdb->ecode = TDB_ERR_RDONLY; |
| 883 | return -1; |
| 884 | } |
| 885 | |
| 886 | if (tdb->methods->tdb_oob(tdb, off + len, 0) != 0) |
| 887 | return -1; |
| 888 | |
| 889 | if (tdb->map_ptr) { |
| 890 | memcpy(off + (char *)tdb->map_ptr, buf, len); |
| 891 | } else if (pwrite(tdb->fd, buf, len, off) != (ssize_t)len) { |
| 892 | /* Ensure ecode is set for log fn. */ |
| 893 | tdb->ecode = TDB_ERR_IO; |
| 894 | TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_write failed at %d len=%d (%s)\n", |
| 895 | off, len, strerror(errno))); |
| 896 | return TDB_ERRCODE(TDB_ERR_IO, -1); |
| 897 | } |
| 898 | return 0; |
| 899 | } |
| 900 | |
| 901 | /* Endian conversion: we only ever deal with 4 byte quantities */ |
| 902 | void *tdb_convert(void *buf, u32 size) |
| 903 | { |
| 904 | u32 i, *p = (u32 *)buf; |
| 905 | for (i = 0; i < size / 4; i++) |
| 906 | p[i] = TDB_BYTEREV(p[i]); |
| 907 | return buf; |
| 908 | } |
| 909 | |
| 910 | |
| 911 | /* read a lump of data at a specified offset, maybe convert */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 912 | static int tdb_read(struct tdb_context *tdb, tdb_off_t off, void *buf, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 913 | tdb_len_t len, int cv) |
| 914 | { |
| 915 | if (tdb->methods->tdb_oob(tdb, off + len, 0) != 0) { |
| 916 | return -1; |
| 917 | } |
| 918 | |
| 919 | if (tdb->map_ptr) { |
| 920 | memcpy(buf, off + (char *)tdb->map_ptr, len); |
| 921 | } else { |
| 922 | ssize_t ret = pread(tdb->fd, buf, len, off); |
| 923 | if (ret != (ssize_t)len) { |
| 924 | /* Ensure ecode is set for log fn. */ |
| 925 | tdb->ecode = TDB_ERR_IO; |
| 926 | TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_read failed at %d " |
| 927 | "len=%d ret=%d (%s) map_size=%d\n", |
| 928 | (int)off, (int)len, (int)ret, strerror(errno), |
| 929 | (int)tdb->map_size)); |
| 930 | return TDB_ERRCODE(TDB_ERR_IO, -1); |
| 931 | } |
| 932 | } |
| 933 | if (cv) { |
| 934 | tdb_convert(buf, len); |
| 935 | } |
| 936 | return 0; |
| 937 | } |
| 938 | |
| 939 | |
| 940 | |
| 941 | /* |
| 942 | do an unlocked scan of the hash table heads to find the next non-zero head. The value |
| 943 | will then be confirmed with the lock held |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 944 | */ |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 945 | static void tdb_next_hash_chain(struct tdb_context *tdb, u32 *chain) |
| 946 | { |
| 947 | u32 h = *chain; |
| 948 | if (tdb->map_ptr) { |
| 949 | for (;h < tdb->header.hash_size;h++) { |
| 950 | if (0 != *(u32 *)(TDB_HASH_TOP(h) + (unsigned char *)tdb->map_ptr)) { |
| 951 | break; |
| 952 | } |
| 953 | } |
| 954 | } else { |
| 955 | u32 off=0; |
| 956 | for (;h < tdb->header.hash_size;h++) { |
| 957 | if (tdb_ofs_read(tdb, TDB_HASH_TOP(h), &off) != 0 || off != 0) { |
| 958 | break; |
| 959 | } |
| 960 | } |
| 961 | } |
| 962 | (*chain) = h; |
| 963 | } |
| 964 | |
| 965 | |
| 966 | int tdb_munmap(struct tdb_context *tdb) |
| 967 | { |
| 968 | if (tdb->flags & TDB_INTERNAL) |
| 969 | return 0; |
| 970 | |
| 971 | #ifdef HAVE_MMAP |
| 972 | if (tdb->map_ptr) { |
| 973 | int ret = munmap(tdb->map_ptr, tdb->map_size); |
| 974 | if (ret != 0) |
| 975 | return ret; |
| 976 | } |
| 977 | #endif |
| 978 | tdb->map_ptr = NULL; |
| 979 | return 0; |
| 980 | } |
| 981 | |
| 982 | void tdb_mmap(struct tdb_context *tdb) |
| 983 | { |
| 984 | if (tdb->flags & TDB_INTERNAL) |
| 985 | return; |
| 986 | |
| 987 | #ifdef HAVE_MMAP |
| 988 | if (!(tdb->flags & TDB_NOMMAP)) { |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 989 | tdb->map_ptr = mmap(NULL, tdb->map_size, |
| 990 | PROT_READ|(tdb->read_only? 0:PROT_WRITE), |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 991 | MAP_SHARED|MAP_FILE, tdb->fd, 0); |
| 992 | |
| 993 | /* |
| 994 | * NB. When mmap fails it returns MAP_FAILED *NOT* NULL !!!! |
| 995 | */ |
| 996 | |
| 997 | if (tdb->map_ptr == MAP_FAILED) { |
| 998 | tdb->map_ptr = NULL; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 999 | TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_mmap failed for size %d (%s)\n", |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1000 | tdb->map_size, strerror(errno))); |
| 1001 | } |
| 1002 | } else { |
| 1003 | tdb->map_ptr = NULL; |
| 1004 | } |
| 1005 | #else |
| 1006 | tdb->map_ptr = NULL; |
| 1007 | #endif |
| 1008 | } |
| 1009 | |
| 1010 | /* expand a file. we prefer to use ftruncate, as that is what posix |
| 1011 | says to use for mmap expansion */ |
| 1012 | static int tdb_expand_file(struct tdb_context *tdb, tdb_off_t size, tdb_off_t addition) |
| 1013 | { |
| 1014 | char buf[1024]; |
| 1015 | |
| 1016 | if (tdb->read_only || tdb->traverse_read) { |
| 1017 | tdb->ecode = TDB_ERR_RDONLY; |
| 1018 | return -1; |
| 1019 | } |
| 1020 | |
| 1021 | if (ftruncate(tdb->fd, size+addition) == -1) { |
| 1022 | char b = 0; |
| 1023 | if (pwrite(tdb->fd, &b, 1, (size+addition) - 1) != 1) { |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1024 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "expand_file to %d failed (%s)\n", |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1025 | size+addition, strerror(errno))); |
| 1026 | return -1; |
| 1027 | } |
| 1028 | } |
| 1029 | |
| 1030 | /* now fill the file with something. This ensures that the |
| 1031 | file isn't sparse, which would be very bad if we ran out of |
| 1032 | disk. This must be done with write, not via mmap */ |
| 1033 | memset(buf, TDB_PAD_BYTE, sizeof(buf)); |
| 1034 | while (addition) { |
| 1035 | int n = addition>sizeof(buf)?sizeof(buf):addition; |
| 1036 | int ret = pwrite(tdb->fd, buf, n, size); |
| 1037 | if (ret != n) { |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1038 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "expand_file write of %d failed (%s)\n", |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1039 | n, strerror(errno))); |
| 1040 | return -1; |
| 1041 | } |
| 1042 | addition -= n; |
| 1043 | size += n; |
| 1044 | } |
| 1045 | return 0; |
| 1046 | } |
| 1047 | |
| 1048 | |
| 1049 | /* expand the database at least size bytes by expanding the underlying |
| 1050 | file and doing the mmap again if necessary */ |
| 1051 | int tdb_expand(struct tdb_context *tdb, tdb_off_t size) |
| 1052 | { |
| 1053 | struct list_struct rec; |
| 1054 | tdb_off_t offset; |
| 1055 | |
| 1056 | if (tdb_lock(tdb, -1, F_WRLCK) == -1) { |
| 1057 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "lock failed in tdb_expand\n")); |
| 1058 | return -1; |
| 1059 | } |
| 1060 | |
| 1061 | /* must know about any previous expansions by another process */ |
| 1062 | tdb->methods->tdb_oob(tdb, tdb->map_size + 1, 1); |
| 1063 | |
| 1064 | /* always make room for at least 10 more records, and round |
| 1065 | the database up to a multiple of the page size */ |
| 1066 | size = TDB_ALIGN(tdb->map_size + size*10, tdb->page_size) - tdb->map_size; |
| 1067 | |
| 1068 | if (!(tdb->flags & TDB_INTERNAL)) |
| 1069 | tdb_munmap(tdb); |
| 1070 | |
| 1071 | /* |
| 1072 | * We must ensure the file is unmapped before doing this |
| 1073 | * to ensure consistency with systems like OpenBSD where |
| 1074 | * writes and mmaps are not consistent. |
| 1075 | */ |
| 1076 | |
| 1077 | /* expand the file itself */ |
| 1078 | if (!(tdb->flags & TDB_INTERNAL)) { |
| 1079 | if (tdb->methods->tdb_expand_file(tdb, tdb->map_size, size) != 0) |
| 1080 | goto fail; |
| 1081 | } |
| 1082 | |
| 1083 | tdb->map_size += size; |
| 1084 | |
| 1085 | if (tdb->flags & TDB_INTERNAL) { |
| 1086 | char *new_map_ptr = (char *)realloc(tdb->map_ptr, |
| 1087 | tdb->map_size); |
| 1088 | if (!new_map_ptr) { |
| 1089 | tdb->map_size -= size; |
| 1090 | goto fail; |
| 1091 | } |
| 1092 | tdb->map_ptr = new_map_ptr; |
| 1093 | } else { |
| 1094 | /* |
| 1095 | * We must ensure the file is remapped before adding the space |
| 1096 | * to ensure consistency with systems like OpenBSD where |
| 1097 | * writes and mmaps are not consistent. |
| 1098 | */ |
| 1099 | |
| 1100 | /* We're ok if the mmap fails as we'll fallback to read/write */ |
| 1101 | tdb_mmap(tdb); |
| 1102 | } |
| 1103 | |
| 1104 | /* form a new freelist record */ |
| 1105 | memset(&rec,'\0',sizeof(rec)); |
| 1106 | rec.rec_len = size - sizeof(rec); |
| 1107 | |
| 1108 | /* link it into the free list */ |
| 1109 | offset = tdb->map_size - size; |
| 1110 | if (tdb_free(tdb, offset, &rec) == -1) |
| 1111 | goto fail; |
| 1112 | |
| 1113 | tdb_unlock(tdb, -1, F_WRLCK); |
| 1114 | return 0; |
| 1115 | fail: |
| 1116 | tdb_unlock(tdb, -1, F_WRLCK); |
| 1117 | return -1; |
| 1118 | } |
| 1119 | |
| 1120 | /* read/write a tdb_off_t */ |
| 1121 | int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d) |
| 1122 | { |
| 1123 | return tdb->methods->tdb_read(tdb, offset, (char*)d, sizeof(*d), DOCONV()); |
| 1124 | } |
| 1125 | |
| 1126 | int tdb_ofs_write(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d) |
| 1127 | { |
| 1128 | tdb_off_t off = *d; |
| 1129 | return tdb->methods->tdb_write(tdb, offset, CONVERT(off), sizeof(*d)); |
| 1130 | } |
| 1131 | |
| 1132 | |
| 1133 | /* read a lump of data, allocating the space for it */ |
| 1134 | unsigned char *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t len) |
| 1135 | { |
| 1136 | unsigned char *buf; |
| 1137 | |
| 1138 | /* some systems don't like zero length malloc */ |
| 1139 | if (len == 0) { |
| 1140 | len = 1; |
| 1141 | } |
| 1142 | |
| 1143 | if (!(buf = (unsigned char *)malloc(len))) { |
| 1144 | /* Ensure ecode is set for log fn. */ |
| 1145 | tdb->ecode = TDB_ERR_OOM; |
| 1146 | TDB_LOG((tdb, TDB_DEBUG_ERROR,"tdb_alloc_read malloc failed len=%d (%s)\n", |
| 1147 | len, strerror(errno))); |
| 1148 | return TDB_ERRCODE(TDB_ERR_OOM, buf); |
| 1149 | } |
| 1150 | if (tdb->methods->tdb_read(tdb, offset, buf, len, 0) == -1) { |
| 1151 | SAFE_FREE(buf); |
| 1152 | return NULL; |
| 1153 | } |
| 1154 | return buf; |
| 1155 | } |
| 1156 | |
| 1157 | /* Give a piece of tdb data to a parser */ |
| 1158 | |
| 1159 | int tdb_parse_data(struct tdb_context *tdb, TDB_DATA key, |
| 1160 | tdb_off_t offset, tdb_len_t len, |
| 1161 | int (*parser)(TDB_DATA key, TDB_DATA data, |
| 1162 | void *private_data), |
| 1163 | void *private_data) |
| 1164 | { |
| 1165 | TDB_DATA data; |
| 1166 | int result; |
| 1167 | |
| 1168 | data.dsize = len; |
| 1169 | |
| 1170 | if ((tdb->transaction == NULL) && (tdb->map_ptr != NULL)) { |
| 1171 | /* |
| 1172 | * Optimize by avoiding the malloc/memcpy/free, point the |
| 1173 | * parser directly at the mmap area. |
| 1174 | */ |
| 1175 | if (tdb->methods->tdb_oob(tdb, offset+len, 0) != 0) { |
| 1176 | return -1; |
| 1177 | } |
| 1178 | data.dptr = offset + (unsigned char *)tdb->map_ptr; |
| 1179 | return parser(key, data, private_data); |
| 1180 | } |
| 1181 | |
| 1182 | if (!(data.dptr = tdb_alloc_read(tdb, offset, len))) { |
| 1183 | return -1; |
| 1184 | } |
| 1185 | |
| 1186 | result = parser(key, data, private_data); |
| 1187 | free(data.dptr); |
| 1188 | return result; |
| 1189 | } |
| 1190 | |
| 1191 | /* read/write a record */ |
| 1192 | int tdb_rec_read(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec) |
| 1193 | { |
| 1194 | if (tdb->methods->tdb_read(tdb, offset, rec, sizeof(*rec),DOCONV()) == -1) |
| 1195 | return -1; |
| 1196 | if (TDB_BAD_MAGIC(rec)) { |
| 1197 | /* Ensure ecode is set for log fn. */ |
| 1198 | tdb->ecode = TDB_ERR_CORRUPT; |
| 1199 | TDB_LOG((tdb, TDB_DEBUG_FATAL,"tdb_rec_read bad magic 0x%x at offset=%d\n", rec->magic, offset)); |
| 1200 | return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); |
| 1201 | } |
| 1202 | return tdb->methods->tdb_oob(tdb, rec->next+sizeof(*rec), 0); |
| 1203 | } |
| 1204 | |
| 1205 | int tdb_rec_write(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec) |
| 1206 | { |
| 1207 | struct list_struct r = *rec; |
| 1208 | return tdb->methods->tdb_write(tdb, offset, CONVERT(r), sizeof(r)); |
| 1209 | } |
| 1210 | |
| 1211 | static const struct tdb_methods io_methods = { |
| 1212 | tdb_read, |
| 1213 | tdb_write, |
| 1214 | tdb_next_hash_chain, |
| 1215 | tdb_oob, |
| 1216 | tdb_expand_file, |
| 1217 | tdb_brlock |
| 1218 | }; |
| 1219 | |
| 1220 | /* |
| 1221 | initialise the default methods table |
| 1222 | */ |
| 1223 | void tdb_io_init(struct tdb_context *tdb) |
| 1224 | { |
| 1225 | tdb->methods = &io_methods; |
| 1226 | } |
| 1227 | |
| 1228 | /* file: transaction.c */ |
| 1229 | |
| 1230 | /* |
| 1231 | transaction design: |
| 1232 | |
| 1233 | - only allow a single transaction at a time per database. This makes |
| 1234 | using the transaction API simpler, as otherwise the caller would |
| 1235 | have to cope with temporary failures in transactions that conflict |
| 1236 | with other current transactions |
| 1237 | |
| 1238 | - keep the transaction recovery information in the same file as the |
| 1239 | database, using a special 'transaction recovery' record pointed at |
| 1240 | by the header. This removes the need for extra journal files as |
| 1241 | used by some other databases |
| 1242 | |
| 1243 | - dynamically allocated the transaction recover record, re-using it |
| 1244 | for subsequent transactions. If a larger record is needed then |
| 1245 | tdb_free() the old record to place it on the normal tdb freelist |
| 1246 | before allocating the new record |
| 1247 | |
| 1248 | - during transactions, keep a linked list of writes all that have |
| 1249 | been performed by intercepting all tdb_write() calls. The hooked |
| 1250 | transaction versions of tdb_read() and tdb_write() check this |
| 1251 | linked list and try to use the elements of the list in preference |
| 1252 | to the real database. |
| 1253 | |
| 1254 | - don't allow any locks to be held when a transaction starts, |
| 1255 | otherwise we can end up with deadlock (plus lack of lock nesting |
| 1256 | in posix locks would mean the lock is lost) |
| 1257 | |
| 1258 | - if the caller gains a lock during the transaction but doesn't |
| 1259 | release it then fail the commit |
| 1260 | |
| 1261 | - allow for nested calls to tdb_transaction_start(), re-using the |
| 1262 | existing transaction record. If the inner transaction is cancelled |
| 1263 | then a subsequent commit will fail |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1264 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1265 | - keep a mirrored copy of the tdb hash chain heads to allow for the |
| 1266 | fast hash heads scan on traverse, updating the mirrored copy in |
| 1267 | the transaction version of tdb_write |
| 1268 | |
| 1269 | - allow callers to mix transaction and non-transaction use of tdb, |
| 1270 | although once a transaction is started then an exclusive lock is |
| 1271 | gained until the transaction is committed or cancelled |
| 1272 | |
| 1273 | - the commit stategy involves first saving away all modified data |
| 1274 | into a linearised buffer in the transaction recovery area, then |
| 1275 | marking the transaction recovery area with a magic value to |
| 1276 | indicate a valid recovery record. In total 4 fsync/msync calls are |
| 1277 | needed per commit to prevent race conditions. It might be possible |
| 1278 | to reduce this to 3 or even 2 with some more work. |
| 1279 | |
| 1280 | - check for a valid recovery record on open of the tdb, while the |
| 1281 | global lock is held. Automatically recover from the transaction |
| 1282 | recovery area if needed, then continue with the open as |
| 1283 | usual. This allows for smooth crash recovery with no administrator |
| 1284 | intervention. |
| 1285 | |
| 1286 | - if TDB_NOSYNC is passed to flags in tdb_open then transactions are |
| 1287 | still available, but no transaction recovery area is used and no |
| 1288 | fsync/msync calls are made. |
| 1289 | |
| 1290 | */ |
| 1291 | |
| 1292 | struct tdb_transaction_el { |
| 1293 | struct tdb_transaction_el *next, *prev; |
| 1294 | tdb_off_t offset; |
| 1295 | tdb_len_t length; |
| 1296 | unsigned char *data; |
| 1297 | }; |
| 1298 | |
| 1299 | /* |
| 1300 | hold the context of any current transaction |
| 1301 | */ |
| 1302 | struct tdb_transaction { |
| 1303 | /* we keep a mirrored copy of the tdb hash heads here so |
| 1304 | tdb_next_hash_chain() can operate efficiently */ |
| 1305 | u32 *hash_heads; |
| 1306 | |
| 1307 | /* the original io methods - used to do IOs to the real db */ |
| 1308 | const struct tdb_methods *io_methods; |
| 1309 | |
| 1310 | /* the list of transaction elements. We use a doubly linked |
| 1311 | list with a last pointer to allow us to keep the list |
| 1312 | ordered, with first element at the front of the list. It |
| 1313 | needs to be doubly linked as the read/write traversals need |
| 1314 | to be backwards, while the commit needs to be forwards */ |
| 1315 | struct tdb_transaction_el *elements, *elements_last; |
| 1316 | |
| 1317 | /* non-zero when an internal transaction error has |
| 1318 | occurred. All write operations will then fail until the |
| 1319 | transaction is ended */ |
| 1320 | int transaction_error; |
| 1321 | |
| 1322 | /* when inside a transaction we need to keep track of any |
| 1323 | nested tdb_transaction_start() calls, as these are allowed, |
| 1324 | but don't create a new transaction */ |
| 1325 | int nesting; |
| 1326 | |
| 1327 | /* old file size before transaction */ |
| 1328 | tdb_len_t old_map_size; |
| 1329 | }; |
| 1330 | |
| 1331 | |
| 1332 | /* |
| 1333 | read while in a transaction. We need to check first if the data is in our list |
| 1334 | of transaction elements, then if not do a real read |
| 1335 | */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1336 | static int transaction_read(struct tdb_context *tdb, tdb_off_t off, void *buf, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1337 | tdb_len_t len, int cv) |
| 1338 | { |
| 1339 | struct tdb_transaction_el *el; |
| 1340 | |
| 1341 | /* we need to walk the list backwards to get the most recent data */ |
| 1342 | for (el=tdb->transaction->elements_last;el;el=el->prev) { |
| 1343 | tdb_len_t partial; |
| 1344 | |
| 1345 | if (off+len <= el->offset) { |
| 1346 | continue; |
| 1347 | } |
| 1348 | if (off >= el->offset + el->length) { |
| 1349 | continue; |
| 1350 | } |
| 1351 | |
| 1352 | /* an overlapping read - needs to be split into up to |
| 1353 | 2 reads and a memcpy */ |
| 1354 | if (off < el->offset) { |
| 1355 | partial = el->offset - off; |
| 1356 | if (transaction_read(tdb, off, buf, partial, cv) != 0) { |
| 1357 | goto fail; |
| 1358 | } |
| 1359 | len -= partial; |
| 1360 | off += partial; |
| 1361 | buf = (void *)(partial + (char *)buf); |
| 1362 | } |
| 1363 | if (off + len <= el->offset + el->length) { |
| 1364 | partial = len; |
| 1365 | } else { |
| 1366 | partial = el->offset + el->length - off; |
| 1367 | } |
| 1368 | memcpy(buf, el->data + (off - el->offset), partial); |
| 1369 | if (cv) { |
| 1370 | tdb_convert(buf, len); |
| 1371 | } |
| 1372 | len -= partial; |
| 1373 | off += partial; |
| 1374 | buf = (void *)(partial + (char *)buf); |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1375 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1376 | if (len != 0 && transaction_read(tdb, off, buf, len, cv) != 0) { |
| 1377 | goto fail; |
| 1378 | } |
| 1379 | |
| 1380 | return 0; |
| 1381 | } |
| 1382 | |
| 1383 | /* its not in the transaction elements - do a real read */ |
| 1384 | return tdb->transaction->io_methods->tdb_read(tdb, off, buf, len, cv); |
| 1385 | |
| 1386 | fail: |
| 1387 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "transaction_read: failed at off=%d len=%d\n", off, len)); |
| 1388 | tdb->ecode = TDB_ERR_IO; |
| 1389 | tdb->transaction->transaction_error = 1; |
| 1390 | return -1; |
| 1391 | } |
| 1392 | |
| 1393 | |
| 1394 | /* |
| 1395 | write while in a transaction |
| 1396 | */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1397 | static int transaction_write(struct tdb_context *tdb, tdb_off_t off, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1398 | const void *buf, tdb_len_t len) |
| 1399 | { |
| 1400 | struct tdb_transaction_el *el, *best_el=NULL; |
| 1401 | |
| 1402 | if (len == 0) { |
| 1403 | return 0; |
| 1404 | } |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1405 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1406 | /* if the write is to a hash head, then update the transaction |
| 1407 | hash heads */ |
| 1408 | if (len == sizeof(tdb_off_t) && off >= FREELIST_TOP && |
| 1409 | off < FREELIST_TOP+TDB_HASHTABLE_SIZE(tdb)) { |
| 1410 | u32 chain = (off-FREELIST_TOP) / sizeof(tdb_off_t); |
| 1411 | memcpy(&tdb->transaction->hash_heads[chain], buf, len); |
| 1412 | } |
| 1413 | |
| 1414 | /* first see if we can replace an existing entry */ |
| 1415 | for (el=tdb->transaction->elements_last;el;el=el->prev) { |
| 1416 | tdb_len_t partial; |
| 1417 | |
| 1418 | if (best_el == NULL && off == el->offset+el->length) { |
| 1419 | best_el = el; |
| 1420 | } |
| 1421 | |
| 1422 | if (off+len <= el->offset) { |
| 1423 | continue; |
| 1424 | } |
| 1425 | if (off >= el->offset + el->length) { |
| 1426 | continue; |
| 1427 | } |
| 1428 | |
| 1429 | /* an overlapping write - needs to be split into up to |
| 1430 | 2 writes and a memcpy */ |
| 1431 | if (off < el->offset) { |
| 1432 | partial = el->offset - off; |
| 1433 | if (transaction_write(tdb, off, buf, partial) != 0) { |
| 1434 | goto fail; |
| 1435 | } |
| 1436 | len -= partial; |
| 1437 | off += partial; |
| 1438 | buf = (const void *)(partial + (const char *)buf); |
| 1439 | } |
| 1440 | if (off + len <= el->offset + el->length) { |
| 1441 | partial = len; |
| 1442 | } else { |
| 1443 | partial = el->offset + el->length - off; |
| 1444 | } |
| 1445 | memcpy(el->data + (off - el->offset), buf, partial); |
| 1446 | len -= partial; |
| 1447 | off += partial; |
| 1448 | buf = (const void *)(partial + (const char *)buf); |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1449 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1450 | if (len != 0 && transaction_write(tdb, off, buf, len) != 0) { |
| 1451 | goto fail; |
| 1452 | } |
| 1453 | |
| 1454 | return 0; |
| 1455 | } |
| 1456 | |
| 1457 | /* see if we can append the new entry to an existing entry */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1458 | if (best_el && best_el->offset + best_el->length == off && |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1459 | (off+len < tdb->transaction->old_map_size || |
| 1460 | off > tdb->transaction->old_map_size)) { |
| 1461 | unsigned char *data = best_el->data; |
| 1462 | el = best_el; |
| 1463 | el->data = (unsigned char *)realloc(el->data, |
| 1464 | el->length + len); |
| 1465 | if (el->data == NULL) { |
| 1466 | tdb->ecode = TDB_ERR_OOM; |
| 1467 | tdb->transaction->transaction_error = 1; |
| 1468 | el->data = data; |
| 1469 | return -1; |
| 1470 | } |
| 1471 | if (buf) { |
| 1472 | memcpy(el->data + el->length, buf, len); |
| 1473 | } else { |
| 1474 | memset(el->data + el->length, TDB_PAD_BYTE, len); |
| 1475 | } |
| 1476 | el->length += len; |
| 1477 | return 0; |
| 1478 | } |
| 1479 | |
| 1480 | /* add a new entry at the end of the list */ |
| 1481 | el = (struct tdb_transaction_el *)malloc(sizeof(*el)); |
| 1482 | if (el == NULL) { |
| 1483 | tdb->ecode = TDB_ERR_OOM; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1484 | tdb->transaction->transaction_error = 1; |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1485 | return -1; |
| 1486 | } |
| 1487 | el->next = NULL; |
| 1488 | el->prev = tdb->transaction->elements_last; |
| 1489 | el->offset = off; |
| 1490 | el->length = len; |
| 1491 | el->data = (unsigned char *)malloc(len); |
| 1492 | if (el->data == NULL) { |
| 1493 | free(el); |
| 1494 | tdb->ecode = TDB_ERR_OOM; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1495 | tdb->transaction->transaction_error = 1; |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1496 | return -1; |
| 1497 | } |
| 1498 | if (buf) { |
| 1499 | memcpy(el->data, buf, len); |
| 1500 | } else { |
| 1501 | memset(el->data, TDB_PAD_BYTE, len); |
| 1502 | } |
| 1503 | if (el->prev) { |
| 1504 | el->prev->next = el; |
| 1505 | } else { |
| 1506 | tdb->transaction->elements = el; |
| 1507 | } |
| 1508 | tdb->transaction->elements_last = el; |
| 1509 | return 0; |
| 1510 | |
| 1511 | fail: |
| 1512 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "transaction_write: failed at off=%d len=%d\n", off, len)); |
| 1513 | tdb->ecode = TDB_ERR_IO; |
| 1514 | tdb->transaction->transaction_error = 1; |
| 1515 | return -1; |
| 1516 | } |
| 1517 | |
| 1518 | /* |
| 1519 | accelerated hash chain head search, using the cached hash heads |
| 1520 | */ |
| 1521 | static void transaction_next_hash_chain(struct tdb_context *tdb, u32 *chain) |
| 1522 | { |
| 1523 | u32 h = *chain; |
| 1524 | for (;h < tdb->header.hash_size;h++) { |
| 1525 | /* the +1 takes account of the freelist */ |
| 1526 | if (0 != tdb->transaction->hash_heads[h+1]) { |
| 1527 | break; |
| 1528 | } |
| 1529 | } |
| 1530 | (*chain) = h; |
| 1531 | } |
| 1532 | |
| 1533 | /* |
| 1534 | out of bounds check during a transaction |
| 1535 | */ |
| 1536 | static int transaction_oob(struct tdb_context *tdb, tdb_off_t len, int probe) |
| 1537 | { |
| 1538 | if (len <= tdb->map_size) { |
| 1539 | return 0; |
| 1540 | } |
| 1541 | return TDB_ERRCODE(TDB_ERR_IO, -1); |
| 1542 | } |
| 1543 | |
| 1544 | /* |
| 1545 | transaction version of tdb_expand(). |
| 1546 | */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1547 | static int transaction_expand_file(struct tdb_context *tdb, tdb_off_t size, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1548 | tdb_off_t addition) |
| 1549 | { |
| 1550 | /* add a write to the transaction elements, so subsequent |
| 1551 | reads see the zero data */ |
| 1552 | if (transaction_write(tdb, size, NULL, addition) != 0) { |
| 1553 | return -1; |
| 1554 | } |
| 1555 | |
| 1556 | return 0; |
| 1557 | } |
| 1558 | |
| 1559 | /* |
| 1560 | brlock during a transaction - ignore them |
| 1561 | */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1562 | static int transaction_brlock(struct tdb_context *tdb, tdb_off_t offset, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1563 | int rw_type, int lck_type, int probe, size_t len) |
| 1564 | { |
| 1565 | return 0; |
| 1566 | } |
| 1567 | |
| 1568 | static const struct tdb_methods transaction_methods = { |
| 1569 | transaction_read, |
| 1570 | transaction_write, |
| 1571 | transaction_next_hash_chain, |
| 1572 | transaction_oob, |
| 1573 | transaction_expand_file, |
| 1574 | transaction_brlock |
| 1575 | }; |
| 1576 | |
| 1577 | |
| 1578 | /* |
| 1579 | start a tdb transaction. No token is returned, as only a single |
| 1580 | transaction is allowed to be pending per tdb_context |
| 1581 | */ |
| 1582 | int tdb_transaction_start(struct tdb_context *tdb) |
| 1583 | { |
| 1584 | /* some sanity checks */ |
| 1585 | if (tdb->read_only || (tdb->flags & TDB_INTERNAL) || tdb->traverse_read) { |
| 1586 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_start: cannot start a transaction on a read-only or internal db\n")); |
| 1587 | tdb->ecode = TDB_ERR_EINVAL; |
| 1588 | return -1; |
| 1589 | } |
| 1590 | |
| 1591 | /* cope with nested tdb_transaction_start() calls */ |
| 1592 | if (tdb->transaction != NULL) { |
| 1593 | tdb->transaction->nesting++; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1594 | TDB_LOG((tdb, TDB_DEBUG_TRACE, "tdb_transaction_start: nesting %d\n", |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1595 | tdb->transaction->nesting)); |
| 1596 | return 0; |
| 1597 | } |
| 1598 | |
| 1599 | if (tdb->num_locks != 0 || tdb->global_lock.count) { |
| 1600 | /* the caller must not have any locks when starting a |
| 1601 | transaction as otherwise we'll be screwed by lack |
| 1602 | of nested locks in posix */ |
| 1603 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_start: cannot start a transaction with locks held\n")); |
| 1604 | tdb->ecode = TDB_ERR_LOCK; |
| 1605 | return -1; |
| 1606 | } |
| 1607 | |
| 1608 | if (tdb->travlocks.next != NULL) { |
| 1609 | /* you cannot use transactions inside a traverse (although you can use |
| 1610 | traverse inside a transaction) as otherwise you can end up with |
| 1611 | deadlock */ |
| 1612 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_start: cannot start a transaction within a traverse\n")); |
| 1613 | tdb->ecode = TDB_ERR_LOCK; |
| 1614 | return -1; |
| 1615 | } |
| 1616 | |
| 1617 | tdb->transaction = (struct tdb_transaction *) |
| 1618 | calloc(sizeof(struct tdb_transaction), 1); |
| 1619 | if (tdb->transaction == NULL) { |
| 1620 | tdb->ecode = TDB_ERR_OOM; |
| 1621 | return -1; |
| 1622 | } |
| 1623 | |
| 1624 | /* get the transaction write lock. This is a blocking lock. As |
| 1625 | discussed with Volker, there are a number of ways we could |
| 1626 | make this async, which we will probably do in the future */ |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 1627 | if (tdb_transaction_lock(tdb, F_WRLCK) == -1) { |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1628 | SAFE_FREE(tdb->transaction); |
| 1629 | return -1; |
| 1630 | } |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1631 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1632 | /* get a read lock from the freelist to the end of file. This |
| 1633 | is upgraded to a write lock during the commit */ |
| 1634 | if (tdb_brlock(tdb, FREELIST_TOP, F_RDLCK, F_SETLKW, 0, 0) == -1) { |
| 1635 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_start: failed to get hash locks\n")); |
| 1636 | tdb->ecode = TDB_ERR_LOCK; |
| 1637 | goto fail; |
| 1638 | } |
| 1639 | |
| 1640 | /* setup a copy of the hash table heads so the hash scan in |
| 1641 | traverse can be fast */ |
| 1642 | tdb->transaction->hash_heads = (u32 *) |
| 1643 | calloc(tdb->header.hash_size+1, sizeof(u32)); |
| 1644 | if (tdb->transaction->hash_heads == NULL) { |
| 1645 | tdb->ecode = TDB_ERR_OOM; |
| 1646 | goto fail; |
| 1647 | } |
| 1648 | if (tdb->methods->tdb_read(tdb, FREELIST_TOP, tdb->transaction->hash_heads, |
| 1649 | TDB_HASHTABLE_SIZE(tdb), 0) != 0) { |
| 1650 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_start: failed to read hash heads\n")); |
| 1651 | tdb->ecode = TDB_ERR_IO; |
| 1652 | goto fail; |
| 1653 | } |
| 1654 | |
| 1655 | /* make sure we know about any file expansions already done by |
| 1656 | anyone else */ |
| 1657 | tdb->methods->tdb_oob(tdb, tdb->map_size + 1, 1); |
| 1658 | tdb->transaction->old_map_size = tdb->map_size; |
| 1659 | |
| 1660 | /* finally hook the io methods, replacing them with |
| 1661 | transaction specific methods */ |
| 1662 | tdb->transaction->io_methods = tdb->methods; |
| 1663 | tdb->methods = &transaction_methods; |
| 1664 | |
| 1665 | /* by calling this transaction write here, we ensure that we don't grow the |
| 1666 | transaction linked list due to hash table updates */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1667 | if (transaction_write(tdb, FREELIST_TOP, tdb->transaction->hash_heads, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1668 | TDB_HASHTABLE_SIZE(tdb)) != 0) { |
| 1669 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_start: failed to prime hash table\n")); |
| 1670 | tdb->ecode = TDB_ERR_IO; |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 1671 | tdb->methods = tdb->transaction->io_methods; |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1672 | goto fail; |
| 1673 | } |
| 1674 | |
| 1675 | return 0; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1676 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1677 | fail: |
| 1678 | tdb_brlock(tdb, FREELIST_TOP, F_UNLCK, F_SETLKW, 0, 0); |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 1679 | tdb_transaction_unlock(tdb); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1680 | SAFE_FREE(tdb->transaction->hash_heads); |
| 1681 | SAFE_FREE(tdb->transaction); |
| 1682 | return -1; |
| 1683 | } |
| 1684 | |
| 1685 | |
| 1686 | /* |
| 1687 | cancel the current transaction |
| 1688 | */ |
| 1689 | int tdb_transaction_cancel(struct tdb_context *tdb) |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1690 | { |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1691 | if (tdb->transaction == NULL) { |
| 1692 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_cancel: no transaction\n")); |
| 1693 | return -1; |
| 1694 | } |
| 1695 | |
| 1696 | if (tdb->transaction->nesting != 0) { |
| 1697 | tdb->transaction->transaction_error = 1; |
| 1698 | tdb->transaction->nesting--; |
| 1699 | return 0; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1700 | } |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1701 | |
| 1702 | tdb->map_size = tdb->transaction->old_map_size; |
| 1703 | |
| 1704 | /* free all the transaction elements */ |
| 1705 | while (tdb->transaction->elements) { |
| 1706 | struct tdb_transaction_el *el = tdb->transaction->elements; |
| 1707 | tdb->transaction->elements = el->next; |
| 1708 | free(el->data); |
| 1709 | free(el); |
| 1710 | } |
| 1711 | |
| 1712 | /* remove any global lock created during the transaction */ |
| 1713 | if (tdb->global_lock.count != 0) { |
| 1714 | tdb_brlock(tdb, FREELIST_TOP, F_UNLCK, F_SETLKW, 0, 4*tdb->header.hash_size); |
| 1715 | tdb->global_lock.count = 0; |
| 1716 | } |
| 1717 | |
| 1718 | /* remove any locks created during the transaction */ |
| 1719 | if (tdb->num_locks != 0) { |
| 1720 | int i; |
| 1721 | for (i=0;i<tdb->num_lockrecs;i++) { |
| 1722 | tdb_brlock(tdb,FREELIST_TOP+4*tdb->lockrecs[i].list, |
| 1723 | F_UNLCK,F_SETLKW, 0, 1); |
| 1724 | } |
| 1725 | tdb->num_locks = 0; |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 1726 | tdb->num_lockrecs = 0; |
| 1727 | SAFE_FREE(tdb->lockrecs); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1728 | } |
| 1729 | |
| 1730 | /* restore the normal io methods */ |
| 1731 | tdb->methods = tdb->transaction->io_methods; |
| 1732 | |
| 1733 | tdb_brlock(tdb, FREELIST_TOP, F_UNLCK, F_SETLKW, 0, 0); |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 1734 | tdb_transaction_unlock(tdb); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1735 | SAFE_FREE(tdb->transaction->hash_heads); |
| 1736 | SAFE_FREE(tdb->transaction); |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1737 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1738 | return 0; |
| 1739 | } |
| 1740 | |
| 1741 | /* |
| 1742 | sync to disk |
| 1743 | */ |
| 1744 | static int transaction_sync(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t length) |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1745 | { |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1746 | if (fsync(tdb->fd) != 0) { |
| 1747 | tdb->ecode = TDB_ERR_IO; |
| 1748 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction: fsync failed\n")); |
| 1749 | return -1; |
| 1750 | } |
Theodore Ts'o | db40c20 | 2011-11-28 12:31:29 -0500 | [diff] [blame] | 1751 | #if defined(HAVE_MSYNC) && defined(MS_SYNC) |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1752 | if (tdb->map_ptr) { |
| 1753 | tdb_off_t moffset = offset & ~(tdb->page_size-1); |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1754 | if (msync(moffset + (char *)tdb->map_ptr, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1755 | length + (offset - moffset), MS_SYNC) != 0) { |
| 1756 | tdb->ecode = TDB_ERR_IO; |
| 1757 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction: msync failed - %s\n", |
| 1758 | strerror(errno))); |
| 1759 | return -1; |
| 1760 | } |
| 1761 | } |
| 1762 | #endif |
| 1763 | return 0; |
| 1764 | } |
| 1765 | |
| 1766 | |
| 1767 | /* |
| 1768 | work out how much space the linearised recovery data will consume |
| 1769 | */ |
| 1770 | static tdb_len_t tdb_recovery_size(struct tdb_context *tdb) |
| 1771 | { |
| 1772 | struct tdb_transaction_el *el; |
| 1773 | tdb_len_t recovery_size = 0; |
| 1774 | |
| 1775 | recovery_size = sizeof(u32); |
| 1776 | for (el=tdb->transaction->elements;el;el=el->next) { |
| 1777 | if (el->offset >= tdb->transaction->old_map_size) { |
| 1778 | continue; |
| 1779 | } |
| 1780 | recovery_size += 2*sizeof(tdb_off_t) + el->length; |
| 1781 | } |
| 1782 | |
| 1783 | return recovery_size; |
| 1784 | } |
| 1785 | |
| 1786 | /* |
| 1787 | allocate the recovery area, or use an existing recovery area if it is |
| 1788 | large enough |
| 1789 | */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1790 | static int tdb_recovery_allocate(struct tdb_context *tdb, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1791 | tdb_len_t *recovery_size, |
| 1792 | tdb_off_t *recovery_offset, |
| 1793 | tdb_len_t *recovery_max_size) |
| 1794 | { |
| 1795 | struct list_struct rec; |
| 1796 | const struct tdb_methods *methods = tdb->transaction->io_methods; |
| 1797 | tdb_off_t recovery_head; |
| 1798 | |
| 1799 | if (tdb_ofs_read(tdb, TDB_RECOVERY_HEAD, &recovery_head) == -1) { |
| 1800 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to read recovery head\n")); |
| 1801 | return -1; |
| 1802 | } |
| 1803 | |
| 1804 | rec.rec_len = 0; |
| 1805 | |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1806 | if (recovery_head != 0 && |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1807 | methods->tdb_read(tdb, recovery_head, &rec, sizeof(rec), DOCONV()) == -1) { |
| 1808 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to read recovery record\n")); |
| 1809 | return -1; |
| 1810 | } |
| 1811 | |
| 1812 | *recovery_size = tdb_recovery_size(tdb); |
| 1813 | |
| 1814 | if (recovery_head != 0 && *recovery_size <= rec.rec_len) { |
| 1815 | /* it fits in the existing area */ |
| 1816 | *recovery_max_size = rec.rec_len; |
| 1817 | *recovery_offset = recovery_head; |
| 1818 | return 0; |
| 1819 | } |
| 1820 | |
| 1821 | /* we need to free up the old recovery area, then allocate a |
| 1822 | new one at the end of the file. Note that we cannot use |
| 1823 | tdb_allocate() to allocate the new one as that might return |
| 1824 | us an area that is being currently used (as of the start of |
| 1825 | the transaction) */ |
| 1826 | if (recovery_head != 0) { |
| 1827 | if (tdb_free(tdb, recovery_head, &rec) == -1) { |
| 1828 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to free previous recovery area\n")); |
| 1829 | return -1; |
| 1830 | } |
| 1831 | } |
| 1832 | |
| 1833 | /* the tdb_free() call might have increased the recovery size */ |
| 1834 | *recovery_size = tdb_recovery_size(tdb); |
| 1835 | |
| 1836 | /* round up to a multiple of page size */ |
| 1837 | *recovery_max_size = TDB_ALIGN(sizeof(rec) + *recovery_size, tdb->page_size) - sizeof(rec); |
| 1838 | *recovery_offset = tdb->map_size; |
| 1839 | recovery_head = *recovery_offset; |
| 1840 | |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1841 | if (methods->tdb_expand_file(tdb, tdb->transaction->old_map_size, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1842 | (tdb->map_size - tdb->transaction->old_map_size) + |
| 1843 | sizeof(rec) + *recovery_max_size) == -1) { |
| 1844 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to create recovery area\n")); |
| 1845 | return -1; |
| 1846 | } |
| 1847 | |
| 1848 | /* remap the file (if using mmap) */ |
| 1849 | methods->tdb_oob(tdb, tdb->map_size + 1, 1); |
| 1850 | |
| 1851 | /* we have to reset the old map size so that we don't try to expand the file |
| 1852 | again in the transaction commit, which would destroy the recovery area */ |
| 1853 | tdb->transaction->old_map_size = tdb->map_size; |
| 1854 | |
| 1855 | /* write the recovery header offset and sync - we can sync without a race here |
| 1856 | as the magic ptr in the recovery record has not been set */ |
| 1857 | CONVERT(recovery_head); |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1858 | if (methods->tdb_write(tdb, TDB_RECOVERY_HEAD, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1859 | &recovery_head, sizeof(tdb_off_t)) == -1) { |
| 1860 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to write recovery head\n")); |
| 1861 | return -1; |
| 1862 | } |
| 1863 | |
| 1864 | return 0; |
| 1865 | } |
| 1866 | |
| 1867 | |
| 1868 | /* |
| 1869 | setup the recovery data that will be used on a crash during commit |
| 1870 | */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1871 | static int transaction_setup_recovery(struct tdb_context *tdb, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1872 | tdb_off_t *magic_offset) |
| 1873 | { |
| 1874 | struct tdb_transaction_el *el; |
| 1875 | tdb_len_t recovery_size; |
| 1876 | unsigned char *data, *p; |
| 1877 | const struct tdb_methods *methods = tdb->transaction->io_methods; |
| 1878 | struct list_struct *rec; |
| 1879 | tdb_off_t recovery_offset, recovery_max_size; |
| 1880 | tdb_off_t old_map_size = tdb->transaction->old_map_size; |
| 1881 | u32 magic, tailer; |
| 1882 | |
| 1883 | /* |
| 1884 | check that the recovery area has enough space |
| 1885 | */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1886 | if (tdb_recovery_allocate(tdb, &recovery_size, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1887 | &recovery_offset, &recovery_max_size) == -1) { |
| 1888 | return -1; |
| 1889 | } |
| 1890 | |
| 1891 | data = (unsigned char *)malloc(recovery_size + sizeof(*rec)); |
| 1892 | if (data == NULL) { |
| 1893 | tdb->ecode = TDB_ERR_OOM; |
| 1894 | return -1; |
| 1895 | } |
| 1896 | |
| 1897 | rec = (struct list_struct *)data; |
| 1898 | memset(rec, 0, sizeof(*rec)); |
| 1899 | |
| 1900 | rec->magic = 0; |
| 1901 | rec->data_len = recovery_size; |
| 1902 | rec->rec_len = recovery_max_size; |
| 1903 | rec->key_len = old_map_size; |
| 1904 | CONVERT(rec); |
| 1905 | |
| 1906 | /* build the recovery data into a single blob to allow us to do a single |
| 1907 | large write, which should be more efficient */ |
| 1908 | p = data + sizeof(*rec); |
| 1909 | for (el=tdb->transaction->elements;el;el=el->next) { |
| 1910 | if (el->offset >= old_map_size) { |
| 1911 | continue; |
| 1912 | } |
| 1913 | if (el->offset + el->length > tdb->transaction->old_map_size) { |
| 1914 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_setup_recovery: transaction data over new region boundary\n")); |
| 1915 | free(data); |
| 1916 | tdb->ecode = TDB_ERR_CORRUPT; |
| 1917 | return -1; |
| 1918 | } |
| 1919 | memcpy(p, &el->offset, 4); |
| 1920 | memcpy(p+4, &el->length, 4); |
| 1921 | if (DOCONV()) { |
| 1922 | tdb_convert(p, 8); |
| 1923 | } |
| 1924 | /* the recovery area contains the old data, not the |
| 1925 | new data, so we have to call the original tdb_read |
| 1926 | method to get it */ |
| 1927 | if (methods->tdb_read(tdb, el->offset, p + 8, el->length, 0) != 0) { |
| 1928 | free(data); |
| 1929 | tdb->ecode = TDB_ERR_IO; |
| 1930 | return -1; |
| 1931 | } |
| 1932 | p += 8 + el->length; |
| 1933 | } |
| 1934 | |
| 1935 | /* and the tailer */ |
| 1936 | tailer = sizeof(*rec) + recovery_max_size; |
| 1937 | memcpy(p, &tailer, 4); |
| 1938 | CONVERT(p); |
| 1939 | |
| 1940 | /* write the recovery data to the recovery area */ |
| 1941 | if (methods->tdb_write(tdb, recovery_offset, data, sizeof(*rec) + recovery_size) == -1) { |
| 1942 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_setup_recovery: failed to write recovery data\n")); |
| 1943 | free(data); |
| 1944 | tdb->ecode = TDB_ERR_IO; |
| 1945 | return -1; |
| 1946 | } |
| 1947 | |
| 1948 | /* as we don't have ordered writes, we have to sync the recovery |
| 1949 | data before we update the magic to indicate that the recovery |
| 1950 | data is present */ |
| 1951 | if (transaction_sync(tdb, recovery_offset, sizeof(*rec) + recovery_size) == -1) { |
| 1952 | free(data); |
| 1953 | return -1; |
| 1954 | } |
| 1955 | |
| 1956 | free(data); |
| 1957 | |
| 1958 | magic = TDB_RECOVERY_MAGIC; |
| 1959 | CONVERT(magic); |
| 1960 | |
| 1961 | *magic_offset = recovery_offset + offsetof(struct list_struct, magic); |
| 1962 | |
| 1963 | if (methods->tdb_write(tdb, *magic_offset, &magic, sizeof(magic)) == -1) { |
| 1964 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_setup_recovery: failed to write recovery magic\n")); |
| 1965 | tdb->ecode = TDB_ERR_IO; |
| 1966 | return -1; |
| 1967 | } |
| 1968 | |
| 1969 | /* ensure the recovery magic marker is on disk */ |
| 1970 | if (transaction_sync(tdb, *magic_offset, sizeof(magic)) == -1) { |
| 1971 | return -1; |
| 1972 | } |
| 1973 | |
| 1974 | return 0; |
| 1975 | } |
| 1976 | |
| 1977 | /* |
| 1978 | commit the current transaction |
| 1979 | */ |
| 1980 | int tdb_transaction_commit(struct tdb_context *tdb) |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 1981 | { |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 1982 | const struct tdb_methods *methods; |
| 1983 | tdb_off_t magic_offset = 0; |
| 1984 | u32 zero = 0; |
| 1985 | |
| 1986 | if (tdb->transaction == NULL) { |
| 1987 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_commit: no transaction\n")); |
| 1988 | return -1; |
| 1989 | } |
| 1990 | |
| 1991 | if (tdb->transaction->transaction_error) { |
| 1992 | tdb->ecode = TDB_ERR_IO; |
| 1993 | tdb_transaction_cancel(tdb); |
| 1994 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_commit: transaction error pending\n")); |
| 1995 | return -1; |
| 1996 | } |
| 1997 | |
| 1998 | if (tdb->transaction->nesting != 0) { |
| 1999 | tdb->transaction->nesting--; |
| 2000 | return 0; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2001 | } |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2002 | |
| 2003 | /* check for a null transaction */ |
| 2004 | if (tdb->transaction->elements == NULL) { |
| 2005 | tdb_transaction_cancel(tdb); |
| 2006 | return 0; |
| 2007 | } |
| 2008 | |
| 2009 | methods = tdb->transaction->io_methods; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2010 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2011 | /* if there are any locks pending then the caller has not |
| 2012 | nested their locks properly, so fail the transaction */ |
| 2013 | if (tdb->num_locks || tdb->global_lock.count) { |
| 2014 | tdb->ecode = TDB_ERR_LOCK; |
| 2015 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_commit: locks pending on commit\n")); |
| 2016 | tdb_transaction_cancel(tdb); |
| 2017 | return -1; |
| 2018 | } |
| 2019 | |
| 2020 | /* upgrade the main transaction lock region to a write lock */ |
| 2021 | if (tdb_brlock_upgrade(tdb, FREELIST_TOP, 0) == -1) { |
| 2022 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_start: failed to upgrade hash locks\n")); |
| 2023 | tdb->ecode = TDB_ERR_LOCK; |
| 2024 | tdb_transaction_cancel(tdb); |
| 2025 | return -1; |
| 2026 | } |
| 2027 | |
| 2028 | /* get the global lock - this prevents new users attaching to the database |
| 2029 | during the commit */ |
| 2030 | if (tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0, 1) == -1) { |
| 2031 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_commit: failed to get global lock\n")); |
| 2032 | tdb->ecode = TDB_ERR_LOCK; |
| 2033 | tdb_transaction_cancel(tdb); |
| 2034 | return -1; |
| 2035 | } |
| 2036 | |
| 2037 | if (!(tdb->flags & TDB_NOSYNC)) { |
| 2038 | /* write the recovery data to the end of the file */ |
| 2039 | if (transaction_setup_recovery(tdb, &magic_offset) == -1) { |
| 2040 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: failed to setup recovery data\n")); |
| 2041 | tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1); |
| 2042 | tdb_transaction_cancel(tdb); |
| 2043 | return -1; |
| 2044 | } |
| 2045 | } |
| 2046 | |
| 2047 | /* expand the file to the new size if needed */ |
| 2048 | if (tdb->map_size != tdb->transaction->old_map_size) { |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2049 | if (methods->tdb_expand_file(tdb, tdb->transaction->old_map_size, |
| 2050 | tdb->map_size - |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2051 | tdb->transaction->old_map_size) == -1) { |
| 2052 | tdb->ecode = TDB_ERR_IO; |
| 2053 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: expansion failed\n")); |
| 2054 | tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1); |
| 2055 | tdb_transaction_cancel(tdb); |
| 2056 | return -1; |
| 2057 | } |
| 2058 | tdb->map_size = tdb->transaction->old_map_size; |
| 2059 | methods->tdb_oob(tdb, tdb->map_size + 1, 1); |
| 2060 | } |
| 2061 | |
| 2062 | /* perform all the writes */ |
| 2063 | while (tdb->transaction->elements) { |
| 2064 | struct tdb_transaction_el *el = tdb->transaction->elements; |
| 2065 | |
| 2066 | if (methods->tdb_write(tdb, el->offset, el->data, el->length) == -1) { |
| 2067 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: write failed during commit\n")); |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2068 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2069 | /* we've overwritten part of the data and |
| 2070 | possibly expanded the file, so we need to |
| 2071 | run the crash recovery code */ |
| 2072 | tdb->methods = methods; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2073 | tdb_transaction_recover(tdb); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2074 | |
| 2075 | tdb_transaction_cancel(tdb); |
| 2076 | tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1); |
| 2077 | |
| 2078 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: write failed\n")); |
| 2079 | return -1; |
| 2080 | } |
| 2081 | tdb->transaction->elements = el->next; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2082 | free(el->data); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2083 | free(el); |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2084 | } |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2085 | |
| 2086 | if (!(tdb->flags & TDB_NOSYNC)) { |
| 2087 | /* ensure the new data is on disk */ |
| 2088 | if (transaction_sync(tdb, 0, tdb->map_size) == -1) { |
| 2089 | return -1; |
| 2090 | } |
| 2091 | |
| 2092 | /* remove the recovery marker */ |
| 2093 | if (methods->tdb_write(tdb, magic_offset, &zero, 4) == -1) { |
| 2094 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_commit: failed to remove recovery magic\n")); |
| 2095 | return -1; |
| 2096 | } |
| 2097 | |
| 2098 | /* ensure the recovery marker has been removed on disk */ |
| 2099 | if (transaction_sync(tdb, magic_offset, 4) == -1) { |
| 2100 | return -1; |
| 2101 | } |
| 2102 | } |
| 2103 | |
| 2104 | tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1); |
| 2105 | |
| 2106 | /* |
| 2107 | TODO: maybe write to some dummy hdr field, or write to magic |
| 2108 | offset without mmap, before the last sync, instead of the |
| 2109 | utime() call |
| 2110 | */ |
| 2111 | |
| 2112 | /* on some systems (like Linux 2.6.x) changes via mmap/msync |
| 2113 | don't change the mtime of the file, this means the file may |
| 2114 | not be backed up (as tdb rounding to block sizes means that |
| 2115 | file size changes are quite rare too). The following forces |
| 2116 | mtime changes when a transaction completes */ |
| 2117 | #ifdef HAVE_UTIME |
| 2118 | utime(tdb->name, NULL); |
| 2119 | #endif |
| 2120 | |
| 2121 | /* use a transaction cancel to free memory and remove the |
| 2122 | transaction locks */ |
| 2123 | tdb_transaction_cancel(tdb); |
| 2124 | return 0; |
| 2125 | } |
| 2126 | |
| 2127 | |
| 2128 | /* |
| 2129 | recover from an aborted transaction. Must be called with exclusive |
| 2130 | database write access already established (including the global |
| 2131 | lock to prevent new processes attaching) |
| 2132 | */ |
| 2133 | int tdb_transaction_recover(struct tdb_context *tdb) |
| 2134 | { |
| 2135 | tdb_off_t recovery_head, recovery_eof; |
| 2136 | unsigned char *data, *p; |
| 2137 | u32 zero = 0; |
| 2138 | struct list_struct rec; |
| 2139 | |
| 2140 | /* find the recovery area */ |
| 2141 | if (tdb_ofs_read(tdb, TDB_RECOVERY_HEAD, &recovery_head) == -1) { |
| 2142 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to read recovery head\n")); |
| 2143 | tdb->ecode = TDB_ERR_IO; |
| 2144 | return -1; |
| 2145 | } |
| 2146 | |
| 2147 | if (recovery_head == 0) { |
| 2148 | /* we have never allocated a recovery record */ |
| 2149 | return 0; |
| 2150 | } |
| 2151 | |
| 2152 | /* read the recovery record */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2153 | if (tdb->methods->tdb_read(tdb, recovery_head, &rec, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2154 | sizeof(rec), DOCONV()) == -1) { |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2155 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to read recovery record\n")); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2156 | tdb->ecode = TDB_ERR_IO; |
| 2157 | return -1; |
| 2158 | } |
| 2159 | |
| 2160 | if (rec.magic != TDB_RECOVERY_MAGIC) { |
| 2161 | /* there is no valid recovery data */ |
| 2162 | return 0; |
| 2163 | } |
| 2164 | |
| 2165 | if (tdb->read_only) { |
| 2166 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: attempt to recover read only database\n")); |
| 2167 | tdb->ecode = TDB_ERR_CORRUPT; |
| 2168 | return -1; |
| 2169 | } |
| 2170 | |
| 2171 | recovery_eof = rec.key_len; |
| 2172 | |
| 2173 | data = (unsigned char *)malloc(rec.data_len); |
| 2174 | if (data == NULL) { |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2175 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to allocate recovery data\n")); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2176 | tdb->ecode = TDB_ERR_OOM; |
| 2177 | return -1; |
| 2178 | } |
| 2179 | |
| 2180 | /* read the full recovery data */ |
| 2181 | if (tdb->methods->tdb_read(tdb, recovery_head + sizeof(rec), data, |
| 2182 | rec.data_len, 0) == -1) { |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2183 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to read recovery data\n")); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2184 | tdb->ecode = TDB_ERR_IO; |
| 2185 | return -1; |
| 2186 | } |
| 2187 | |
| 2188 | /* recover the file data */ |
| 2189 | p = data; |
| 2190 | while (p+8 < data + rec.data_len) { |
| 2191 | u32 ofs, len; |
| 2192 | if (DOCONV()) { |
| 2193 | tdb_convert(p, 8); |
| 2194 | } |
| 2195 | memcpy(&ofs, p, 4); |
| 2196 | memcpy(&len, p+4, 4); |
| 2197 | |
| 2198 | if (tdb->methods->tdb_write(tdb, ofs, p+8, len) == -1) { |
| 2199 | free(data); |
| 2200 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to recover %d bytes at offset %d\n", len, ofs)); |
| 2201 | tdb->ecode = TDB_ERR_IO; |
| 2202 | return -1; |
| 2203 | } |
| 2204 | p += 8 + len; |
| 2205 | } |
| 2206 | |
| 2207 | free(data); |
| 2208 | |
| 2209 | if (transaction_sync(tdb, 0, tdb->map_size) == -1) { |
| 2210 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to sync recovery\n")); |
| 2211 | tdb->ecode = TDB_ERR_IO; |
| 2212 | return -1; |
| 2213 | } |
| 2214 | |
| 2215 | /* if the recovery area is after the recovered eof then remove it */ |
| 2216 | if (recovery_eof <= recovery_head) { |
| 2217 | if (tdb_ofs_write(tdb, TDB_RECOVERY_HEAD, &zero) == -1) { |
| 2218 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to remove recovery head\n")); |
| 2219 | tdb->ecode = TDB_ERR_IO; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2220 | return -1; |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2221 | } |
| 2222 | } |
| 2223 | |
| 2224 | /* remove the recovery magic */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2225 | if (tdb_ofs_write(tdb, recovery_head + offsetof(struct list_struct, magic), |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2226 | &zero) == -1) { |
| 2227 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to remove recovery magic\n")); |
| 2228 | tdb->ecode = TDB_ERR_IO; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2229 | return -1; |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2230 | } |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2231 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2232 | /* reduce the file size to the old size */ |
| 2233 | tdb_munmap(tdb); |
| 2234 | if (ftruncate(tdb->fd, recovery_eof) != 0) { |
| 2235 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to reduce to recovery size\n")); |
| 2236 | tdb->ecode = TDB_ERR_IO; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2237 | return -1; |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2238 | } |
| 2239 | tdb->map_size = recovery_eof; |
| 2240 | tdb_mmap(tdb); |
| 2241 | |
| 2242 | if (transaction_sync(tdb, 0, recovery_eof) == -1) { |
| 2243 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_transaction_recover: failed to sync2 recovery\n")); |
| 2244 | tdb->ecode = TDB_ERR_IO; |
| 2245 | return -1; |
| 2246 | } |
| 2247 | |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2248 | TDB_LOG((tdb, TDB_DEBUG_TRACE, "tdb_transaction_recover: recovered %d byte database\n", |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2249 | recovery_eof)); |
| 2250 | |
| 2251 | /* all done */ |
| 2252 | return 0; |
| 2253 | } |
| 2254 | |
| 2255 | /* file: freelist.c */ |
| 2256 | |
| 2257 | /* read a freelist record and check for simple errors */ |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2258 | static int tdb_rec_free_read(struct tdb_context *tdb, tdb_off_t off, struct list_struct *rec) |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2259 | { |
| 2260 | if (tdb->methods->tdb_read(tdb, off, rec, sizeof(*rec),DOCONV()) == -1) |
| 2261 | return -1; |
| 2262 | |
| 2263 | if (rec->magic == TDB_MAGIC) { |
| 2264 | /* this happens when a app is showdown while deleting a record - we should |
| 2265 | not completely fail when this happens */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2266 | TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_rec_free_read non-free magic 0x%x at offset=%d - fixing\n", |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2267 | rec->magic, off)); |
| 2268 | rec->magic = TDB_FREE_MAGIC; |
| 2269 | if (tdb->methods->tdb_write(tdb, off, rec, sizeof(*rec)) == -1) |
| 2270 | return -1; |
| 2271 | } |
| 2272 | |
| 2273 | if (rec->magic != TDB_FREE_MAGIC) { |
| 2274 | /* Ensure ecode is set for log fn. */ |
| 2275 | tdb->ecode = TDB_ERR_CORRUPT; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2276 | TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_rec_free_read bad magic 0x%x at offset=%d\n", |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2277 | rec->magic, off)); |
| 2278 | return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); |
| 2279 | } |
| 2280 | if (tdb->methods->tdb_oob(tdb, rec->next+sizeof(*rec), 0) != 0) |
| 2281 | return -1; |
| 2282 | return 0; |
| 2283 | } |
| 2284 | |
| 2285 | |
| 2286 | |
| 2287 | /* Remove an element from the freelist. Must have alloc lock. */ |
| 2288 | static int remove_from_freelist(struct tdb_context *tdb, tdb_off_t off, tdb_off_t next) |
| 2289 | { |
| 2290 | tdb_off_t last_ptr, i; |
| 2291 | |
| 2292 | /* read in the freelist top */ |
| 2293 | last_ptr = FREELIST_TOP; |
| 2294 | while (tdb_ofs_read(tdb, last_ptr, &i) != -1 && i != 0) { |
| 2295 | if (i == off) { |
| 2296 | /* We've found it! */ |
| 2297 | return tdb_ofs_write(tdb, last_ptr, &next); |
| 2298 | } |
| 2299 | /* Follow chain (next offset is at start of record) */ |
| 2300 | last_ptr = i; |
| 2301 | } |
| 2302 | TDB_LOG((tdb, TDB_DEBUG_FATAL,"remove_from_freelist: not on list at off=%d\n", off)); |
| 2303 | return TDB_ERRCODE(TDB_ERR_CORRUPT, -1); |
| 2304 | } |
| 2305 | |
| 2306 | |
| 2307 | /* update a record tailer (must hold allocation lock) */ |
| 2308 | static int update_tailer(struct tdb_context *tdb, tdb_off_t offset, |
| 2309 | const struct list_struct *rec) |
| 2310 | { |
| 2311 | tdb_off_t totalsize; |
| 2312 | |
| 2313 | /* Offset of tailer from record header */ |
| 2314 | totalsize = sizeof(*rec) + rec->rec_len; |
| 2315 | return tdb_ofs_write(tdb, offset + totalsize - sizeof(tdb_off_t), |
| 2316 | &totalsize); |
| 2317 | } |
| 2318 | |
| 2319 | /* Add an element into the freelist. Merge adjacent records if |
| 2320 | neccessary. */ |
| 2321 | int tdb_free(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec) |
| 2322 | { |
| 2323 | tdb_off_t right, left; |
| 2324 | |
| 2325 | /* Allocation and tailer lock */ |
| 2326 | if (tdb_lock(tdb, -1, F_WRLCK) != 0) |
| 2327 | return -1; |
| 2328 | |
| 2329 | /* set an initial tailer, so if we fail we don't leave a bogus record */ |
| 2330 | if (update_tailer(tdb, offset, rec) != 0) { |
| 2331 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: update_tailer failed!\n")); |
| 2332 | goto fail; |
| 2333 | } |
| 2334 | |
| 2335 | /* Look right first (I'm an Australian, dammit) */ |
| 2336 | right = offset + sizeof(*rec) + rec->rec_len; |
| 2337 | if (right + sizeof(*rec) <= tdb->map_size) { |
| 2338 | struct list_struct r; |
| 2339 | |
| 2340 | if (tdb->methods->tdb_read(tdb, right, &r, sizeof(r), DOCONV()) == -1) { |
| 2341 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: right read failed at %u\n", right)); |
| 2342 | goto left; |
| 2343 | } |
| 2344 | |
| 2345 | /* If it's free, expand to include it. */ |
| 2346 | if (r.magic == TDB_FREE_MAGIC) { |
| 2347 | if (remove_from_freelist(tdb, right, r.next) == -1) { |
| 2348 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: right free failed at %u\n", right)); |
| 2349 | goto left; |
| 2350 | } |
| 2351 | rec->rec_len += sizeof(r) + r.rec_len; |
| 2352 | } |
| 2353 | } |
| 2354 | |
| 2355 | left: |
| 2356 | /* Look left */ |
| 2357 | left = offset - sizeof(tdb_off_t); |
| 2358 | if (left > TDB_DATA_START(tdb->header.hash_size)) { |
| 2359 | struct list_struct l; |
| 2360 | tdb_off_t leftsize; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2361 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2362 | /* Read in tailer and jump back to header */ |
| 2363 | if (tdb_ofs_read(tdb, left, &leftsize) == -1) { |
| 2364 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: left offset read failed at %u\n", left)); |
| 2365 | goto update; |
| 2366 | } |
| 2367 | |
| 2368 | /* it could be uninitialised data */ |
| 2369 | if (leftsize == 0 || leftsize == TDB_PAD_U32) { |
| 2370 | goto update; |
| 2371 | } |
| 2372 | |
| 2373 | left = offset - leftsize; |
| 2374 | |
| 2375 | /* Now read in record */ |
| 2376 | if (tdb->methods->tdb_read(tdb, left, &l, sizeof(l), DOCONV()) == -1) { |
| 2377 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: left read failed at %u (%u)\n", left, leftsize)); |
| 2378 | goto update; |
| 2379 | } |
| 2380 | |
| 2381 | /* If it's free, expand to include it. */ |
| 2382 | if (l.magic == TDB_FREE_MAGIC) { |
| 2383 | if (remove_from_freelist(tdb, left, l.next) == -1) { |
| 2384 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: left free failed at %u\n", left)); |
| 2385 | goto update; |
| 2386 | } else { |
| 2387 | offset = left; |
| 2388 | rec->rec_len += leftsize; |
| 2389 | } |
| 2390 | } |
| 2391 | } |
| 2392 | |
| 2393 | update: |
| 2394 | if (update_tailer(tdb, offset, rec) == -1) { |
| 2395 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free: update_tailer failed at %u\n", offset)); |
| 2396 | goto fail; |
| 2397 | } |
| 2398 | |
| 2399 | /* Now, prepend to free list */ |
| 2400 | rec->magic = TDB_FREE_MAGIC; |
| 2401 | |
| 2402 | if (tdb_ofs_read(tdb, FREELIST_TOP, &rec->next) == -1 || |
| 2403 | tdb_rec_write(tdb, offset, rec) == -1 || |
| 2404 | tdb_ofs_write(tdb, FREELIST_TOP, &offset) == -1) { |
| 2405 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_free record write failed at offset=%d\n", offset)); |
| 2406 | goto fail; |
| 2407 | } |
| 2408 | |
| 2409 | /* And we're done. */ |
| 2410 | tdb_unlock(tdb, -1, F_WRLCK); |
| 2411 | return 0; |
| 2412 | |
| 2413 | fail: |
| 2414 | tdb_unlock(tdb, -1, F_WRLCK); |
| 2415 | return -1; |
| 2416 | } |
| 2417 | |
| 2418 | |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2419 | /* |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2420 | the core of tdb_allocate - called when we have decided which |
| 2421 | free list entry to use |
| 2422 | */ |
| 2423 | static tdb_off_t tdb_allocate_ofs(struct tdb_context *tdb, tdb_len_t length, tdb_off_t rec_ptr, |
| 2424 | struct list_struct *rec, tdb_off_t last_ptr) |
| 2425 | { |
| 2426 | struct list_struct newrec; |
| 2427 | tdb_off_t newrec_ptr; |
| 2428 | |
| 2429 | memset(&newrec, '\0', sizeof(newrec)); |
| 2430 | |
| 2431 | /* found it - now possibly split it up */ |
| 2432 | if (rec->rec_len > length + MIN_REC_SIZE) { |
| 2433 | /* Length of left piece */ |
| 2434 | length = TDB_ALIGN(length, TDB_ALIGNMENT); |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2435 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2436 | /* Right piece to go on free list */ |
| 2437 | newrec.rec_len = rec->rec_len - (sizeof(*rec) + length); |
| 2438 | newrec_ptr = rec_ptr + sizeof(*rec) + length; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2439 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2440 | /* And left record is shortened */ |
| 2441 | rec->rec_len = length; |
| 2442 | } else { |
| 2443 | newrec_ptr = 0; |
| 2444 | } |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2445 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2446 | /* Remove allocated record from the free list */ |
| 2447 | if (tdb_ofs_write(tdb, last_ptr, &rec->next) == -1) { |
| 2448 | return 0; |
| 2449 | } |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2450 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2451 | /* Update header: do this before we drop alloc |
| 2452 | lock, otherwise tdb_free() might try to |
| 2453 | merge with us, thinking we're free. |
| 2454 | (Thanks Jeremy Allison). */ |
| 2455 | rec->magic = TDB_MAGIC; |
| 2456 | if (tdb_rec_write(tdb, rec_ptr, rec) == -1) { |
| 2457 | return 0; |
| 2458 | } |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2459 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2460 | /* Did we create new block? */ |
| 2461 | if (newrec_ptr) { |
| 2462 | /* Update allocated record tailer (we |
| 2463 | shortened it). */ |
| 2464 | if (update_tailer(tdb, rec_ptr, rec) == -1) { |
| 2465 | return 0; |
| 2466 | } |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2467 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2468 | /* Free new record */ |
| 2469 | if (tdb_free(tdb, newrec_ptr, &newrec) == -1) { |
| 2470 | return 0; |
| 2471 | } |
| 2472 | } |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2473 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2474 | /* all done - return the new record offset */ |
| 2475 | return rec_ptr; |
| 2476 | } |
| 2477 | |
| 2478 | /* allocate some space from the free list. The offset returned points |
| 2479 | to a unconnected list_struct within the database with room for at |
| 2480 | least length bytes of total data |
| 2481 | |
| 2482 | 0 is returned if the space could not be allocated |
| 2483 | */ |
| 2484 | tdb_off_t tdb_allocate(struct tdb_context *tdb, tdb_len_t length, struct list_struct *rec) |
| 2485 | { |
| 2486 | tdb_off_t rec_ptr, last_ptr, newrec_ptr; |
| 2487 | struct { |
| 2488 | tdb_off_t rec_ptr, last_ptr; |
| 2489 | tdb_len_t rec_len; |
| 2490 | } bestfit; |
| 2491 | |
| 2492 | if (tdb_lock(tdb, -1, F_WRLCK) == -1) |
| 2493 | return 0; |
| 2494 | |
| 2495 | /* Extra bytes required for tailer */ |
| 2496 | length += sizeof(tdb_off_t); |
| 2497 | |
| 2498 | again: |
| 2499 | last_ptr = FREELIST_TOP; |
| 2500 | |
| 2501 | /* read in the freelist top */ |
| 2502 | if (tdb_ofs_read(tdb, FREELIST_TOP, &rec_ptr) == -1) |
| 2503 | goto fail; |
| 2504 | |
| 2505 | bestfit.rec_ptr = 0; |
| 2506 | bestfit.last_ptr = 0; |
| 2507 | bestfit.rec_len = 0; |
| 2508 | |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2509 | /* |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2510 | this is a best fit allocation strategy. Originally we used |
| 2511 | a first fit strategy, but it suffered from massive fragmentation |
| 2512 | issues when faced with a slowly increasing record size. |
| 2513 | */ |
| 2514 | while (rec_ptr) { |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2515 | if (tdb_rec_free_read(tdb, rec_ptr, rec) == -1) { |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2516 | goto fail; |
| 2517 | } |
| 2518 | |
| 2519 | if (rec->rec_len >= length) { |
| 2520 | if (bestfit.rec_ptr == 0 || |
| 2521 | rec->rec_len < bestfit.rec_len) { |
| 2522 | bestfit.rec_len = rec->rec_len; |
| 2523 | bestfit.rec_ptr = rec_ptr; |
| 2524 | bestfit.last_ptr = last_ptr; |
| 2525 | /* consider a fit to be good enough if |
| 2526 | we aren't wasting more than half |
| 2527 | the space */ |
| 2528 | if (bestfit.rec_len < 2*length) { |
| 2529 | break; |
| 2530 | } |
| 2531 | } |
| 2532 | } |
| 2533 | |
| 2534 | /* move to the next record */ |
| 2535 | last_ptr = rec_ptr; |
| 2536 | rec_ptr = rec->next; |
| 2537 | } |
| 2538 | |
| 2539 | if (bestfit.rec_ptr != 0) { |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2540 | if (tdb_rec_free_read(tdb, bestfit.rec_ptr, rec) == -1) { |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2541 | goto fail; |
| 2542 | } |
| 2543 | |
| 2544 | newrec_ptr = tdb_allocate_ofs(tdb, length, bestfit.rec_ptr, rec, bestfit.last_ptr); |
| 2545 | tdb_unlock(tdb, -1, F_WRLCK); |
| 2546 | return newrec_ptr; |
| 2547 | } |
| 2548 | |
| 2549 | /* we didn't find enough space. See if we can expand the |
| 2550 | database and if we can then try again */ |
| 2551 | if (tdb_expand(tdb, length + sizeof(*rec)) == 0) |
| 2552 | goto again; |
| 2553 | fail: |
| 2554 | tdb_unlock(tdb, -1, F_WRLCK); |
| 2555 | return 0; |
| 2556 | } |
| 2557 | |
| 2558 | /* file: freelistcheck.c */ |
| 2559 | |
| 2560 | /* Check the freelist is good and contains no loops. |
| 2561 | Very memory intensive - only do this as a consistency |
| 2562 | checker. Heh heh - uses an in memory tdb as the storage |
| 2563 | for the "seen" record list. For some reason this strikes |
| 2564 | me as extremely clever as I don't have to write another tree |
| 2565 | data structure implementation :-). |
| 2566 | */ |
| 2567 | |
| 2568 | static int seen_insert(struct tdb_context *mem_tdb, tdb_off_t rec_ptr) |
| 2569 | { |
| 2570 | TDB_DATA key, data; |
| 2571 | |
| 2572 | memset(&data, '\0', sizeof(data)); |
| 2573 | key.dptr = (unsigned char *)&rec_ptr; |
| 2574 | key.dsize = sizeof(rec_ptr); |
| 2575 | return tdb_store(mem_tdb, key, data, TDB_INSERT); |
| 2576 | } |
| 2577 | |
| 2578 | int tdb_validate_freelist(struct tdb_context *tdb, int *pnum_entries) |
| 2579 | { |
| 2580 | struct tdb_context *mem_tdb = NULL; |
| 2581 | struct list_struct rec; |
| 2582 | tdb_off_t rec_ptr, last_ptr; |
| 2583 | int ret = -1; |
| 2584 | |
| 2585 | *pnum_entries = 0; |
| 2586 | |
| 2587 | mem_tdb = tdb_open("flval", tdb->header.hash_size, |
| 2588 | TDB_INTERNAL, O_RDWR, 0600); |
| 2589 | if (!mem_tdb) { |
| 2590 | return -1; |
| 2591 | } |
| 2592 | |
| 2593 | if (tdb_lock(tdb, -1, F_WRLCK) == -1) { |
| 2594 | tdb_close(mem_tdb); |
| 2595 | return 0; |
| 2596 | } |
| 2597 | |
| 2598 | last_ptr = FREELIST_TOP; |
| 2599 | |
| 2600 | /* Store the FREELIST_TOP record. */ |
| 2601 | if (seen_insert(mem_tdb, last_ptr) == -1) { |
| 2602 | ret = TDB_ERRCODE(TDB_ERR_CORRUPT, -1); |
| 2603 | goto fail; |
| 2604 | } |
| 2605 | |
| 2606 | /* read in the freelist top */ |
| 2607 | if (tdb_ofs_read(tdb, FREELIST_TOP, &rec_ptr) == -1) { |
| 2608 | goto fail; |
| 2609 | } |
| 2610 | |
| 2611 | while (rec_ptr) { |
| 2612 | |
| 2613 | /* If we can't store this record (we've seen it |
| 2614 | before) then the free list has a loop and must |
| 2615 | be corrupt. */ |
| 2616 | |
| 2617 | if (seen_insert(mem_tdb, rec_ptr)) { |
| 2618 | ret = TDB_ERRCODE(TDB_ERR_CORRUPT, -1); |
| 2619 | goto fail; |
| 2620 | } |
| 2621 | |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2622 | if (tdb_rec_free_read(tdb, rec_ptr, &rec) == -1) { |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2623 | goto fail; |
| 2624 | } |
| 2625 | |
| 2626 | /* move to the next record */ |
| 2627 | last_ptr = rec_ptr; |
| 2628 | rec_ptr = rec.next; |
| 2629 | *pnum_entries += 1; |
| 2630 | } |
| 2631 | |
| 2632 | ret = 0; |
| 2633 | |
| 2634 | fail: |
| 2635 | |
| 2636 | tdb_close(mem_tdb); |
| 2637 | tdb_unlock(tdb, -1, F_WRLCK); |
| 2638 | return ret; |
| 2639 | } |
| 2640 | |
| 2641 | /* file: traverse.c */ |
| 2642 | |
| 2643 | /* Uses traverse lock: 0 = finish, -1 = error, other = record offset */ |
| 2644 | static int tdb_next_lock(struct tdb_context *tdb, struct tdb_traverse_lock *tlock, |
| 2645 | struct list_struct *rec) |
| 2646 | { |
| 2647 | int want_next = (tlock->off != 0); |
| 2648 | |
| 2649 | /* Lock each chain from the start one. */ |
| 2650 | for (; tlock->hash < tdb->header.hash_size; tlock->hash++) { |
| 2651 | if (!tlock->off && tlock->hash != 0) { |
| 2652 | /* this is an optimisation for the common case where |
| 2653 | the hash chain is empty, which is particularly |
| 2654 | common for the use of tdb with ldb, where large |
| 2655 | hashes are used. In that case we spend most of our |
| 2656 | time in tdb_brlock(), locking empty hash chains. |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2657 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2658 | To avoid this, we do an unlocked pre-check to see |
| 2659 | if the hash chain is empty before starting to look |
| 2660 | inside it. If it is empty then we can avoid that |
| 2661 | hash chain. If it isn't empty then we can't believe |
| 2662 | the value we get back, as we read it without a |
| 2663 | lock, so instead we get the lock and re-fetch the |
| 2664 | value below. |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2665 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2666 | Notice that not doing this optimisation on the |
| 2667 | first hash chain is critical. We must guarantee |
| 2668 | that we have done at least one fcntl lock at the |
| 2669 | start of a search to guarantee that memory is |
| 2670 | coherent on SMP systems. If records are added by |
| 2671 | others during the search then thats OK, and we |
| 2672 | could possibly miss those with this trick, but we |
| 2673 | could miss them anyway without this trick, so the |
| 2674 | semantics don't change. |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2675 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2676 | With a non-indexed ldb search this trick gains us a |
| 2677 | factor of around 80 in speed on a linux 2.6.x |
| 2678 | system (testing using ldbtest). |
| 2679 | */ |
| 2680 | tdb->methods->next_hash_chain(tdb, &tlock->hash); |
| 2681 | if (tlock->hash == tdb->header.hash_size) { |
| 2682 | continue; |
| 2683 | } |
| 2684 | } |
| 2685 | |
| 2686 | if (tdb_lock(tdb, tlock->hash, tlock->lock_rw) == -1) |
| 2687 | return -1; |
| 2688 | |
| 2689 | /* No previous record? Start at top of chain. */ |
| 2690 | if (!tlock->off) { |
| 2691 | if (tdb_ofs_read(tdb, TDB_HASH_TOP(tlock->hash), |
| 2692 | &tlock->off) == -1) |
| 2693 | goto fail; |
| 2694 | } else { |
| 2695 | /* Otherwise unlock the previous record. */ |
| 2696 | if (tdb_unlock_record(tdb, tlock->off) != 0) |
| 2697 | goto fail; |
| 2698 | } |
| 2699 | |
| 2700 | if (want_next) { |
| 2701 | /* We have offset of old record: grab next */ |
| 2702 | if (tdb_rec_read(tdb, tlock->off, rec) == -1) |
| 2703 | goto fail; |
| 2704 | tlock->off = rec->next; |
| 2705 | } |
| 2706 | |
| 2707 | /* Iterate through chain */ |
| 2708 | while( tlock->off) { |
| 2709 | tdb_off_t current; |
| 2710 | if (tdb_rec_read(tdb, tlock->off, rec) == -1) |
| 2711 | goto fail; |
| 2712 | |
| 2713 | /* Detect infinite loops. From "Shlomi Yaakobovich" <Shlomi@exanet.com>. */ |
| 2714 | if (tlock->off == rec->next) { |
| 2715 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_next_lock: loop detected.\n")); |
| 2716 | goto fail; |
| 2717 | } |
| 2718 | |
| 2719 | if (!TDB_DEAD(rec)) { |
| 2720 | /* Woohoo: we found one! */ |
| 2721 | if (tdb_lock_record(tdb, tlock->off) != 0) |
| 2722 | goto fail; |
| 2723 | return tlock->off; |
| 2724 | } |
| 2725 | |
| 2726 | /* Try to clean dead ones from old traverses */ |
| 2727 | current = tlock->off; |
| 2728 | tlock->off = rec->next; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2729 | if (!(tdb->read_only || tdb->traverse_read) && |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2730 | tdb_do_delete(tdb, current, rec) != 0) |
| 2731 | goto fail; |
| 2732 | } |
| 2733 | tdb_unlock(tdb, tlock->hash, tlock->lock_rw); |
| 2734 | want_next = 0; |
| 2735 | } |
| 2736 | /* We finished iteration without finding anything */ |
| 2737 | return TDB_ERRCODE(TDB_SUCCESS, 0); |
| 2738 | |
| 2739 | fail: |
| 2740 | tlock->off = 0; |
| 2741 | if (tdb_unlock(tdb, tlock->hash, tlock->lock_rw) != 0) |
| 2742 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_next_lock: On error unlock failed!\n")); |
| 2743 | return -1; |
| 2744 | } |
| 2745 | |
| 2746 | /* traverse the entire database - calling fn(tdb, key, data) on each element. |
| 2747 | return -1 on error or the record count traversed |
| 2748 | if fn is NULL then it is not called |
| 2749 | a non-zero return value from fn() indicates that the traversal should stop |
| 2750 | */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2751 | static int tdb_traverse_internal(struct tdb_context *tdb, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2752 | tdb_traverse_func fn, void *private_data, |
| 2753 | struct tdb_traverse_lock *tl) |
| 2754 | { |
| 2755 | TDB_DATA key, dbuf; |
| 2756 | struct list_struct rec; |
| 2757 | int ret, count = 0; |
| 2758 | |
| 2759 | /* This was in the initializaton, above, but the IRIX compiler |
| 2760 | * did not like it. crh |
| 2761 | */ |
| 2762 | tl->next = tdb->travlocks.next; |
| 2763 | |
| 2764 | /* fcntl locks don't stack: beware traverse inside traverse */ |
| 2765 | tdb->travlocks.next = tl; |
| 2766 | |
| 2767 | /* tdb_next_lock places locks on the record returned, and its chain */ |
| 2768 | while ((ret = tdb_next_lock(tdb, tl, &rec)) > 0) { |
| 2769 | count++; |
| 2770 | /* now read the full record */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2771 | key.dptr = tdb_alloc_read(tdb, tl->off + sizeof(rec), |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2772 | rec.key_len + rec.data_len); |
| 2773 | if (!key.dptr) { |
| 2774 | ret = -1; |
| 2775 | if (tdb_unlock(tdb, tl->hash, tl->lock_rw) != 0) |
| 2776 | goto out; |
| 2777 | if (tdb_unlock_record(tdb, tl->off) != 0) |
| 2778 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_traverse: key.dptr == NULL and unlock_record failed!\n")); |
| 2779 | goto out; |
| 2780 | } |
| 2781 | key.dsize = rec.key_len; |
| 2782 | dbuf.dptr = key.dptr + rec.key_len; |
| 2783 | dbuf.dsize = rec.data_len; |
| 2784 | |
| 2785 | /* Drop chain lock, call out */ |
| 2786 | if (tdb_unlock(tdb, tl->hash, tl->lock_rw) != 0) { |
| 2787 | ret = -1; |
| 2788 | SAFE_FREE(key.dptr); |
| 2789 | goto out; |
| 2790 | } |
| 2791 | if (fn && fn(tdb, key, dbuf, private_data)) { |
| 2792 | /* They want us to terminate traversal */ |
| 2793 | ret = count; |
| 2794 | if (tdb_unlock_record(tdb, tl->off) != 0) { |
| 2795 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_traverse: unlock_record failed!\n"));; |
| 2796 | ret = -1; |
| 2797 | } |
| 2798 | SAFE_FREE(key.dptr); |
| 2799 | goto out; |
| 2800 | } |
| 2801 | SAFE_FREE(key.dptr); |
| 2802 | } |
| 2803 | out: |
| 2804 | tdb->travlocks.next = tl->next; |
| 2805 | if (ret < 0) |
| 2806 | return -1; |
| 2807 | else |
| 2808 | return count; |
| 2809 | } |
| 2810 | |
| 2811 | |
| 2812 | /* |
| 2813 | a write style traverse - temporarily marks the db read only |
| 2814 | */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2815 | int tdb_traverse_read(struct tdb_context *tdb, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2816 | tdb_traverse_func fn, void *private_data) |
| 2817 | { |
| 2818 | struct tdb_traverse_lock tl = { NULL, 0, 0, F_RDLCK }; |
| 2819 | int ret; |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2820 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2821 | /* we need to get a read lock on the transaction lock here to |
| 2822 | cope with the lock ordering semantics of solaris10 */ |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2823 | if (tdb_transaction_lock(tdb, F_RDLCK)) { |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2824 | return -1; |
| 2825 | } |
| 2826 | |
| 2827 | tdb->traverse_read++; |
| 2828 | ret = tdb_traverse_internal(tdb, fn, private_data, &tl); |
| 2829 | tdb->traverse_read--; |
| 2830 | |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2831 | tdb_transaction_unlock(tdb); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2832 | |
| 2833 | return ret; |
| 2834 | } |
| 2835 | |
| 2836 | /* |
| 2837 | a write style traverse - needs to get the transaction lock to |
| 2838 | prevent deadlocks |
| 2839 | */ |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2840 | int tdb_traverse(struct tdb_context *tdb, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2841 | tdb_traverse_func fn, void *private_data) |
| 2842 | { |
| 2843 | struct tdb_traverse_lock tl = { NULL, 0, 0, F_WRLCK }; |
| 2844 | int ret; |
| 2845 | |
| 2846 | if (tdb->read_only || tdb->traverse_read) { |
| 2847 | return tdb_traverse_read(tdb, fn, private_data); |
| 2848 | } |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2849 | |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2850 | if (tdb_transaction_lock(tdb, F_WRLCK)) { |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2851 | return -1; |
| 2852 | } |
| 2853 | |
| 2854 | ret = tdb_traverse_internal(tdb, fn, private_data, &tl); |
| 2855 | |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2856 | tdb_transaction_unlock(tdb); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2857 | |
| 2858 | return ret; |
| 2859 | } |
| 2860 | |
| 2861 | |
| 2862 | /* find the first entry in the database and return its key */ |
| 2863 | TDB_DATA tdb_firstkey(struct tdb_context *tdb) |
| 2864 | { |
| 2865 | TDB_DATA key; |
| 2866 | struct list_struct rec; |
| 2867 | |
| 2868 | /* release any old lock */ |
| 2869 | if (tdb_unlock_record(tdb, tdb->travlocks.off) != 0) |
| 2870 | return tdb_null; |
| 2871 | tdb->travlocks.off = tdb->travlocks.hash = 0; |
| 2872 | tdb->travlocks.lock_rw = F_RDLCK; |
| 2873 | |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2874 | /* Grab first record: locks chain and returned record. */ |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2875 | if (tdb_next_lock(tdb, &tdb->travlocks, &rec) <= 0) |
| 2876 | return tdb_null; |
| 2877 | /* now read the key */ |
| 2878 | key.dsize = rec.key_len; |
| 2879 | key.dptr =tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec),key.dsize); |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2880 | |
| 2881 | /* Unlock the hash chain of the record we just read. */ |
| 2882 | if (tdb_unlock(tdb, tdb->travlocks.hash, tdb->travlocks.lock_rw) != 0) |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2883 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_firstkey: error occurred while tdb_unlocking!\n")); |
| 2884 | return key; |
| 2885 | } |
| 2886 | |
| 2887 | /* find the next entry in the database, returning its key */ |
| 2888 | TDB_DATA tdb_nextkey(struct tdb_context *tdb, TDB_DATA oldkey) |
| 2889 | { |
| 2890 | u32 oldhash; |
| 2891 | TDB_DATA key = tdb_null; |
| 2892 | struct list_struct rec; |
| 2893 | unsigned char *k = NULL; |
| 2894 | |
| 2895 | /* Is locked key the old key? If so, traverse will be reliable. */ |
| 2896 | if (tdb->travlocks.off) { |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2897 | if (tdb_lock(tdb,tdb->travlocks.hash,tdb->travlocks.lock_rw)) |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2898 | return tdb_null; |
| 2899 | if (tdb_rec_read(tdb, tdb->travlocks.off, &rec) == -1 |
| 2900 | || !(k = tdb_alloc_read(tdb,tdb->travlocks.off+sizeof(rec), |
| 2901 | rec.key_len)) |
| 2902 | || memcmp(k, oldkey.dptr, oldkey.dsize) != 0) { |
| 2903 | /* No, it wasn't: unlock it and start from scratch */ |
| 2904 | if (tdb_unlock_record(tdb, tdb->travlocks.off) != 0) { |
| 2905 | SAFE_FREE(k); |
| 2906 | return tdb_null; |
| 2907 | } |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2908 | if (tdb_unlock(tdb, tdb->travlocks.hash, tdb->travlocks.lock_rw) != 0) { |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2909 | SAFE_FREE(k); |
| 2910 | return tdb_null; |
| 2911 | } |
| 2912 | tdb->travlocks.off = 0; |
| 2913 | } |
| 2914 | |
| 2915 | SAFE_FREE(k); |
| 2916 | } |
| 2917 | |
| 2918 | if (!tdb->travlocks.off) { |
| 2919 | /* No previous element: do normal find, and lock record */ |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2920 | tdb->travlocks.off = tdb_find_lock_hash(tdb, oldkey, tdb->hash_fn(&oldkey), tdb->travlocks.lock_rw, &rec); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2921 | if (!tdb->travlocks.off) |
| 2922 | return tdb_null; |
| 2923 | tdb->travlocks.hash = BUCKET(rec.full_hash); |
| 2924 | if (tdb_lock_record(tdb, tdb->travlocks.off) != 0) { |
| 2925 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_nextkey: lock_record failed (%s)!\n", strerror(errno))); |
| 2926 | return tdb_null; |
| 2927 | } |
| 2928 | } |
| 2929 | oldhash = tdb->travlocks.hash; |
| 2930 | |
| 2931 | /* Grab next record: locks chain and returned record, |
| 2932 | unlocks old record */ |
| 2933 | if (tdb_next_lock(tdb, &tdb->travlocks, &rec) > 0) { |
| 2934 | key.dsize = rec.key_len; |
| 2935 | key.dptr = tdb_alloc_read(tdb, tdb->travlocks.off+sizeof(rec), |
| 2936 | key.dsize); |
| 2937 | /* Unlock the chain of this new record */ |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2938 | if (tdb_unlock(tdb, tdb->travlocks.hash, tdb->travlocks.lock_rw) != 0) |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2939 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_nextkey: WARNING tdb_unlock failed!\n")); |
| 2940 | } |
| 2941 | /* Unlock the chain of old record */ |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2942 | if (tdb_unlock(tdb, BUCKET(oldhash), tdb->travlocks.lock_rw) != 0) |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2943 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_nextkey: WARNING tdb_unlock failed!\n")); |
| 2944 | return key; |
| 2945 | } |
| 2946 | |
| 2947 | /* file: dump.c */ |
| 2948 | |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2949 | static tdb_off_t tdb_dump_record(struct tdb_context *tdb, int hash, |
| 2950 | tdb_off_t offset) |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2951 | { |
| 2952 | struct list_struct rec; |
| 2953 | tdb_off_t tailer_ofs, tailer; |
| 2954 | |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 2955 | if (tdb->methods->tdb_read(tdb, offset, (char *)&rec, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2956 | sizeof(rec), DOCONV()) == -1) { |
| 2957 | printf("ERROR: failed to read record at %u\n", offset); |
| 2958 | return 0; |
| 2959 | } |
| 2960 | |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2961 | printf(" rec: hash=%d offset=0x%08x next=0x%08x rec_len=%d " |
| 2962 | "key_len=%d data_len=%d full_hash=0x%x magic=0x%x\n", |
| 2963 | hash, offset, rec.next, rec.rec_len, rec.key_len, rec.data_len, |
| 2964 | rec.full_hash, rec.magic); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2965 | |
| 2966 | tailer_ofs = offset + sizeof(rec) + rec.rec_len - sizeof(tdb_off_t); |
| 2967 | |
| 2968 | if (tdb_ofs_read(tdb, tailer_ofs, &tailer) == -1) { |
| 2969 | printf("ERROR: failed to read tailer at %u\n", tailer_ofs); |
| 2970 | return rec.next; |
| 2971 | } |
| 2972 | |
| 2973 | if (tailer != rec.rec_len + sizeof(rec)) { |
| 2974 | printf("ERROR: tailer does not match record! tailer=%u totalsize=%u\n", |
| 2975 | (unsigned int)tailer, (unsigned int)(rec.rec_len + sizeof(rec))); |
| 2976 | } |
| 2977 | return rec.next; |
| 2978 | } |
| 2979 | |
| 2980 | static int tdb_dump_chain(struct tdb_context *tdb, int i) |
| 2981 | { |
| 2982 | tdb_off_t rec_ptr, top; |
| 2983 | |
| 2984 | top = TDB_HASH_TOP(i); |
| 2985 | |
| 2986 | if (tdb_lock(tdb, i, F_WRLCK) != 0) |
| 2987 | return -1; |
| 2988 | |
| 2989 | if (tdb_ofs_read(tdb, top, &rec_ptr) == -1) |
| 2990 | return tdb_unlock(tdb, i, F_WRLCK); |
| 2991 | |
| 2992 | if (rec_ptr) |
| 2993 | printf("hash=%d\n", i); |
| 2994 | |
| 2995 | while (rec_ptr) { |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 2996 | rec_ptr = tdb_dump_record(tdb, i, rec_ptr); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 2997 | } |
| 2998 | |
| 2999 | return tdb_unlock(tdb, i, F_WRLCK); |
| 3000 | } |
| 3001 | |
| 3002 | void tdb_dump_all(struct tdb_context *tdb) |
| 3003 | { |
| 3004 | int i; |
| 3005 | for (i=0;i<tdb->header.hash_size;i++) { |
| 3006 | tdb_dump_chain(tdb, i); |
| 3007 | } |
| 3008 | printf("freelist:\n"); |
| 3009 | tdb_dump_chain(tdb, -1); |
| 3010 | } |
| 3011 | |
| 3012 | int tdb_printfreelist(struct tdb_context *tdb) |
| 3013 | { |
| 3014 | int ret; |
| 3015 | long total_free = 0; |
| 3016 | tdb_off_t offset, rec_ptr; |
| 3017 | struct list_struct rec; |
| 3018 | |
| 3019 | if ((ret = tdb_lock(tdb, -1, F_WRLCK)) != 0) |
| 3020 | return ret; |
| 3021 | |
| 3022 | offset = FREELIST_TOP; |
| 3023 | |
| 3024 | /* read in the freelist top */ |
| 3025 | if (tdb_ofs_read(tdb, offset, &rec_ptr) == -1) { |
| 3026 | tdb_unlock(tdb, -1, F_WRLCK); |
| 3027 | return 0; |
| 3028 | } |
| 3029 | |
| 3030 | printf("freelist top=[0x%08x]\n", rec_ptr ); |
| 3031 | while (rec_ptr) { |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3032 | if (tdb->methods->tdb_read(tdb, rec_ptr, (char *)&rec, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3033 | sizeof(rec), DOCONV()) == -1) { |
| 3034 | tdb_unlock(tdb, -1, F_WRLCK); |
| 3035 | return -1; |
| 3036 | } |
| 3037 | |
| 3038 | if (rec.magic != TDB_FREE_MAGIC) { |
| 3039 | printf("bad magic 0x%08x in free list\n", rec.magic); |
| 3040 | tdb_unlock(tdb, -1, F_WRLCK); |
| 3041 | return -1; |
| 3042 | } |
| 3043 | |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3044 | printf("entry offset=[0x%08x], rec.rec_len = [0x%08x (%d)] (end = 0x%08x)\n", |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3045 | rec_ptr, rec.rec_len, rec.rec_len, rec_ptr + rec.rec_len); |
| 3046 | total_free += rec.rec_len; |
| 3047 | |
| 3048 | /* move to the next record */ |
| 3049 | rec_ptr = rec.next; |
| 3050 | } |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3051 | printf("total rec_len = [0x%08x (%d)]\n", (int)total_free, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3052 | (int)total_free); |
| 3053 | |
| 3054 | return tdb_unlock(tdb, -1, F_WRLCK); |
| 3055 | } |
| 3056 | |
| 3057 | /* file: tdb.c */ |
| 3058 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3059 | /* |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 3060 | non-blocking increment of the tdb sequence number if the tdb has been opened using |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3061 | the TDB_SEQNUM flag |
| 3062 | */ |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 3063 | void tdb_increment_seqnum_nonblock(struct tdb_context *tdb) |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3064 | { |
| 3065 | tdb_off_t seqnum=0; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3066 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3067 | if (!(tdb->flags & TDB_SEQNUM)) { |
| 3068 | return; |
| 3069 | } |
| 3070 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3071 | /* we ignore errors from this, as we have no sane way of |
| 3072 | dealing with them. |
| 3073 | */ |
| 3074 | tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &seqnum); |
| 3075 | seqnum++; |
| 3076 | tdb_ofs_write(tdb, TDB_SEQNUM_OFS, &seqnum); |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 3077 | } |
| 3078 | |
| 3079 | /* |
| 3080 | increment the tdb sequence number if the tdb has been opened using |
| 3081 | the TDB_SEQNUM flag |
| 3082 | */ |
| 3083 | static void tdb_increment_seqnum(struct tdb_context *tdb) |
| 3084 | { |
| 3085 | if (!(tdb->flags & TDB_SEQNUM)) { |
| 3086 | return; |
| 3087 | } |
| 3088 | |
| 3089 | if (tdb_brlock(tdb, TDB_SEQNUM_OFS, F_WRLCK, F_SETLKW, 1, 1) != 0) { |
| 3090 | return; |
| 3091 | } |
| 3092 | |
| 3093 | tdb_increment_seqnum_nonblock(tdb); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3094 | |
| 3095 | tdb_brlock(tdb, TDB_SEQNUM_OFS, F_UNLCK, F_SETLKW, 1, 1); |
| 3096 | } |
| 3097 | |
| 3098 | static int tdb_key_compare(TDB_DATA key, TDB_DATA data, void *private_data) |
| 3099 | { |
| 3100 | return memcmp(data.dptr, key.dptr, data.dsize); |
| 3101 | } |
| 3102 | |
| 3103 | /* Returns 0 on fail. On success, return offset of record, and fills |
| 3104 | in rec */ |
| 3105 | static tdb_off_t tdb_find(struct tdb_context *tdb, TDB_DATA key, u32 hash, |
| 3106 | struct list_struct *r) |
| 3107 | { |
| 3108 | tdb_off_t rec_ptr; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3109 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3110 | /* read in the hash top */ |
| 3111 | if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) |
| 3112 | return 0; |
| 3113 | |
| 3114 | /* keep looking until we find the right record */ |
| 3115 | while (rec_ptr) { |
| 3116 | if (tdb_rec_read(tdb, rec_ptr, r) == -1) |
| 3117 | return 0; |
| 3118 | |
| 3119 | if (!TDB_DEAD(r) && hash==r->full_hash |
| 3120 | && key.dsize==r->key_len |
| 3121 | && tdb_parse_data(tdb, key, rec_ptr + sizeof(*r), |
| 3122 | r->key_len, tdb_key_compare, |
| 3123 | NULL) == 0) { |
| 3124 | return rec_ptr; |
| 3125 | } |
| 3126 | rec_ptr = r->next; |
| 3127 | } |
| 3128 | return TDB_ERRCODE(TDB_ERR_NOEXIST, 0); |
| 3129 | } |
| 3130 | |
| 3131 | /* As tdb_find, but if you succeed, keep the lock */ |
| 3132 | tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash, int locktype, |
| 3133 | struct list_struct *rec) |
| 3134 | { |
| 3135 | u32 rec_ptr; |
| 3136 | |
| 3137 | if (tdb_lock(tdb, BUCKET(hash), locktype) == -1) |
| 3138 | return 0; |
| 3139 | if (!(rec_ptr = tdb_find(tdb, key, hash, rec))) |
| 3140 | tdb_unlock(tdb, BUCKET(hash), locktype); |
| 3141 | return rec_ptr; |
| 3142 | } |
| 3143 | |
| 3144 | |
| 3145 | /* update an entry in place - this only works if the new data size |
| 3146 | is <= the old data size and the key exists. |
| 3147 | on failure return -1. |
| 3148 | */ |
| 3149 | static int tdb_update_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash, TDB_DATA dbuf) |
| 3150 | { |
| 3151 | struct list_struct rec; |
| 3152 | tdb_off_t rec_ptr; |
| 3153 | |
| 3154 | /* find entry */ |
| 3155 | if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) |
| 3156 | return -1; |
| 3157 | |
| 3158 | /* must be long enough key, data and tailer */ |
| 3159 | if (rec.rec_len < key.dsize + dbuf.dsize + sizeof(tdb_off_t)) { |
| 3160 | tdb->ecode = TDB_SUCCESS; /* Not really an error */ |
| 3161 | return -1; |
| 3162 | } |
| 3163 | |
| 3164 | if (tdb->methods->tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len, |
| 3165 | dbuf.dptr, dbuf.dsize) == -1) |
| 3166 | return -1; |
| 3167 | |
| 3168 | if (dbuf.dsize != rec.data_len) { |
| 3169 | /* update size */ |
| 3170 | rec.data_len = dbuf.dsize; |
| 3171 | return tdb_rec_write(tdb, rec_ptr, &rec); |
| 3172 | } |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3173 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3174 | return 0; |
| 3175 | } |
| 3176 | |
| 3177 | /* find an entry in the database given a key */ |
| 3178 | /* If an entry doesn't exist tdb_err will be set to |
| 3179 | * TDB_ERR_NOEXIST. If a key has no data attached |
| 3180 | * then the TDB_DATA will have zero length but |
| 3181 | * a non-zero pointer |
| 3182 | */ |
| 3183 | TDB_DATA tdb_fetch(struct tdb_context *tdb, TDB_DATA key) |
| 3184 | { |
| 3185 | tdb_off_t rec_ptr; |
| 3186 | struct list_struct rec; |
| 3187 | TDB_DATA ret; |
| 3188 | u32 hash; |
| 3189 | |
| 3190 | /* find which hash bucket it is in */ |
| 3191 | hash = tdb->hash_fn(&key); |
| 3192 | if (!(rec_ptr = tdb_find_lock_hash(tdb,key,hash,F_RDLCK,&rec))) |
| 3193 | return tdb_null; |
| 3194 | |
| 3195 | ret.dptr = tdb_alloc_read(tdb, rec_ptr + sizeof(rec) + rec.key_len, |
| 3196 | rec.data_len); |
| 3197 | ret.dsize = rec.data_len; |
| 3198 | tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK); |
| 3199 | return ret; |
| 3200 | } |
| 3201 | |
| 3202 | /* |
| 3203 | * Find an entry in the database and hand the record's data to a parsing |
| 3204 | * function. The parsing function is executed under the chain read lock, so it |
| 3205 | * should be fast and should not block on other syscalls. |
| 3206 | * |
| 3207 | * DONT CALL OTHER TDB CALLS FROM THE PARSER, THIS MIGHT LEAD TO SEGFAULTS. |
| 3208 | * |
| 3209 | * For mmapped tdb's that do not have a transaction open it points the parsing |
| 3210 | * function directly at the mmap area, it avoids the malloc/memcpy in this |
| 3211 | * case. If a transaction is open or no mmap is available, it has to do |
| 3212 | * malloc/read/parse/free. |
| 3213 | * |
| 3214 | * This is interesting for all readers of potentially large data structures in |
| 3215 | * the tdb records, ldb indexes being one example. |
| 3216 | */ |
| 3217 | |
| 3218 | int tdb_parse_record(struct tdb_context *tdb, TDB_DATA key, |
| 3219 | int (*parser)(TDB_DATA key, TDB_DATA data, |
| 3220 | void *private_data), |
| 3221 | void *private_data) |
| 3222 | { |
| 3223 | tdb_off_t rec_ptr; |
| 3224 | struct list_struct rec; |
| 3225 | int ret; |
| 3226 | u32 hash; |
| 3227 | |
| 3228 | /* find which hash bucket it is in */ |
| 3229 | hash = tdb->hash_fn(&key); |
| 3230 | |
| 3231 | if (!(rec_ptr = tdb_find_lock_hash(tdb,key,hash,F_RDLCK,&rec))) { |
| 3232 | return TDB_ERRCODE(TDB_ERR_NOEXIST, 0); |
| 3233 | } |
| 3234 | |
| 3235 | ret = tdb_parse_data(tdb, key, rec_ptr + sizeof(rec) + rec.key_len, |
| 3236 | rec.data_len, parser, private_data); |
| 3237 | |
| 3238 | tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK); |
| 3239 | |
| 3240 | return ret; |
| 3241 | } |
| 3242 | |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3243 | /* check if an entry in the database exists |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3244 | |
| 3245 | note that 1 is returned if the key is found and 0 is returned if not found |
| 3246 | this doesn't match the conventions in the rest of this module, but is |
| 3247 | compatible with gdbm |
| 3248 | */ |
| 3249 | static int tdb_exists_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash) |
| 3250 | { |
| 3251 | struct list_struct rec; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3252 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3253 | if (tdb_find_lock_hash(tdb, key, hash, F_RDLCK, &rec) == 0) |
| 3254 | return 0; |
| 3255 | tdb_unlock(tdb, BUCKET(rec.full_hash), F_RDLCK); |
| 3256 | return 1; |
| 3257 | } |
| 3258 | |
| 3259 | int tdb_exists(struct tdb_context *tdb, TDB_DATA key) |
| 3260 | { |
| 3261 | u32 hash = tdb->hash_fn(&key); |
| 3262 | return tdb_exists_hash(tdb, key, hash); |
| 3263 | } |
| 3264 | |
| 3265 | /* actually delete an entry in the database given the offset */ |
| 3266 | int tdb_do_delete(struct tdb_context *tdb, tdb_off_t rec_ptr, struct list_struct*rec) |
| 3267 | { |
| 3268 | tdb_off_t last_ptr, i; |
| 3269 | struct list_struct lastrec; |
| 3270 | |
| 3271 | if (tdb->read_only || tdb->traverse_read) return -1; |
| 3272 | |
| 3273 | if (tdb_write_lock_record(tdb, rec_ptr) == -1) { |
| 3274 | /* Someone traversing here: mark it as dead */ |
| 3275 | rec->magic = TDB_DEAD_MAGIC; |
| 3276 | return tdb_rec_write(tdb, rec_ptr, rec); |
| 3277 | } |
| 3278 | if (tdb_write_unlock_record(tdb, rec_ptr) != 0) |
| 3279 | return -1; |
| 3280 | |
| 3281 | /* find previous record in hash chain */ |
| 3282 | if (tdb_ofs_read(tdb, TDB_HASH_TOP(rec->full_hash), &i) == -1) |
| 3283 | return -1; |
| 3284 | for (last_ptr = 0; i != rec_ptr; last_ptr = i, i = lastrec.next) |
| 3285 | if (tdb_rec_read(tdb, i, &lastrec) == -1) |
| 3286 | return -1; |
| 3287 | |
| 3288 | /* unlink it: next ptr is at start of record. */ |
| 3289 | if (last_ptr == 0) |
| 3290 | last_ptr = TDB_HASH_TOP(rec->full_hash); |
| 3291 | if (tdb_ofs_write(tdb, last_ptr, &rec->next) == -1) |
| 3292 | return -1; |
| 3293 | |
| 3294 | /* recover the space */ |
| 3295 | if (tdb_free(tdb, rec_ptr, rec) == -1) |
| 3296 | return -1; |
| 3297 | return 0; |
| 3298 | } |
| 3299 | |
| 3300 | static int tdb_count_dead(struct tdb_context *tdb, u32 hash) |
| 3301 | { |
| 3302 | int res = 0; |
| 3303 | tdb_off_t rec_ptr; |
| 3304 | struct list_struct rec; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3305 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3306 | /* read in the hash top */ |
| 3307 | if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) |
| 3308 | return 0; |
| 3309 | |
| 3310 | while (rec_ptr) { |
| 3311 | if (tdb_rec_read(tdb, rec_ptr, &rec) == -1) |
| 3312 | return 0; |
| 3313 | |
| 3314 | if (rec.magic == TDB_DEAD_MAGIC) { |
| 3315 | res += 1; |
| 3316 | } |
| 3317 | rec_ptr = rec.next; |
| 3318 | } |
| 3319 | return res; |
| 3320 | } |
| 3321 | |
| 3322 | /* |
| 3323 | * Purge all DEAD records from a hash chain |
| 3324 | */ |
| 3325 | static int tdb_purge_dead(struct tdb_context *tdb, u32 hash) |
| 3326 | { |
| 3327 | int res = -1; |
| 3328 | struct list_struct rec; |
| 3329 | tdb_off_t rec_ptr; |
| 3330 | |
| 3331 | if (tdb_lock(tdb, -1, F_WRLCK) == -1) { |
| 3332 | return -1; |
| 3333 | } |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3334 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3335 | /* read in the hash top */ |
| 3336 | if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) |
| 3337 | goto fail; |
| 3338 | |
| 3339 | while (rec_ptr) { |
| 3340 | tdb_off_t next; |
| 3341 | |
| 3342 | if (tdb_rec_read(tdb, rec_ptr, &rec) == -1) { |
| 3343 | goto fail; |
| 3344 | } |
| 3345 | |
| 3346 | next = rec.next; |
| 3347 | |
| 3348 | if (rec.magic == TDB_DEAD_MAGIC |
| 3349 | && tdb_do_delete(tdb, rec_ptr, &rec) == -1) { |
| 3350 | goto fail; |
| 3351 | } |
| 3352 | rec_ptr = next; |
| 3353 | } |
| 3354 | res = 0; |
| 3355 | fail: |
| 3356 | tdb_unlock(tdb, -1, F_WRLCK); |
| 3357 | return res; |
| 3358 | } |
| 3359 | |
| 3360 | /* delete an entry in the database given a key */ |
| 3361 | static int tdb_delete_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash) |
| 3362 | { |
| 3363 | tdb_off_t rec_ptr; |
| 3364 | struct list_struct rec; |
| 3365 | int ret; |
| 3366 | |
| 3367 | if (tdb->max_dead_records != 0) { |
| 3368 | |
| 3369 | /* |
| 3370 | * Allow for some dead records per hash chain, mainly for |
| 3371 | * tdb's with a very high create/delete rate like locking.tdb. |
| 3372 | */ |
| 3373 | |
| 3374 | if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1) |
| 3375 | return -1; |
| 3376 | |
| 3377 | if (tdb_count_dead(tdb, hash) >= tdb->max_dead_records) { |
| 3378 | /* |
| 3379 | * Don't let the per-chain freelist grow too large, |
| 3380 | * delete all existing dead records |
| 3381 | */ |
| 3382 | tdb_purge_dead(tdb, hash); |
| 3383 | } |
| 3384 | |
| 3385 | if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) { |
| 3386 | tdb_unlock(tdb, BUCKET(hash), F_WRLCK); |
| 3387 | return -1; |
| 3388 | } |
| 3389 | |
| 3390 | /* |
| 3391 | * Just mark the record as dead. |
| 3392 | */ |
| 3393 | rec.magic = TDB_DEAD_MAGIC; |
| 3394 | ret = tdb_rec_write(tdb, rec_ptr, &rec); |
| 3395 | } |
| 3396 | else { |
| 3397 | if (!(rec_ptr = tdb_find_lock_hash(tdb, key, hash, F_WRLCK, |
| 3398 | &rec))) |
| 3399 | return -1; |
| 3400 | |
| 3401 | ret = tdb_do_delete(tdb, rec_ptr, &rec); |
| 3402 | } |
| 3403 | |
| 3404 | if (ret == 0) { |
| 3405 | tdb_increment_seqnum(tdb); |
| 3406 | } |
| 3407 | |
| 3408 | if (tdb_unlock(tdb, BUCKET(rec.full_hash), F_WRLCK) != 0) |
| 3409 | TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_delete: WARNING tdb_unlock failed!\n")); |
| 3410 | return ret; |
| 3411 | } |
| 3412 | |
| 3413 | int tdb_delete(struct tdb_context *tdb, TDB_DATA key) |
| 3414 | { |
| 3415 | u32 hash = tdb->hash_fn(&key); |
| 3416 | return tdb_delete_hash(tdb, key, hash); |
| 3417 | } |
| 3418 | |
| 3419 | /* |
| 3420 | * See if we have a dead record around with enough space |
| 3421 | */ |
| 3422 | static tdb_off_t tdb_find_dead(struct tdb_context *tdb, u32 hash, |
| 3423 | struct list_struct *r, tdb_len_t length) |
| 3424 | { |
| 3425 | tdb_off_t rec_ptr; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3426 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3427 | /* read in the hash top */ |
| 3428 | if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) |
| 3429 | return 0; |
| 3430 | |
| 3431 | /* keep looking until we find the right record */ |
| 3432 | while (rec_ptr) { |
| 3433 | if (tdb_rec_read(tdb, rec_ptr, r) == -1) |
| 3434 | return 0; |
| 3435 | |
| 3436 | if (TDB_DEAD(r) && r->rec_len >= length) { |
| 3437 | /* |
| 3438 | * First fit for simple coding, TODO: change to best |
| 3439 | * fit |
| 3440 | */ |
| 3441 | return rec_ptr; |
| 3442 | } |
| 3443 | rec_ptr = r->next; |
| 3444 | } |
| 3445 | return 0; |
| 3446 | } |
| 3447 | |
| 3448 | /* store an element in the database, replacing any existing element |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3449 | with the same key |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3450 | |
| 3451 | return 0 on success, -1 on failure |
| 3452 | */ |
| 3453 | int tdb_store(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf, int flag) |
| 3454 | { |
| 3455 | struct list_struct rec; |
| 3456 | u32 hash; |
| 3457 | tdb_off_t rec_ptr; |
| 3458 | char *p = NULL; |
| 3459 | int ret = -1; |
| 3460 | |
| 3461 | if (tdb->read_only || tdb->traverse_read) { |
| 3462 | tdb->ecode = TDB_ERR_RDONLY; |
| 3463 | return -1; |
| 3464 | } |
| 3465 | |
| 3466 | /* find which hash bucket it is in */ |
| 3467 | hash = tdb->hash_fn(&key); |
| 3468 | if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1) |
| 3469 | return -1; |
| 3470 | |
| 3471 | /* check for it existing, on insert. */ |
| 3472 | if (flag == TDB_INSERT) { |
| 3473 | if (tdb_exists_hash(tdb, key, hash)) { |
| 3474 | tdb->ecode = TDB_ERR_EXISTS; |
| 3475 | goto fail; |
| 3476 | } |
| 3477 | } else { |
| 3478 | /* first try in-place update, on modify or replace. */ |
| 3479 | if (tdb_update_hash(tdb, key, hash, dbuf) == 0) { |
| 3480 | goto done; |
| 3481 | } |
| 3482 | if (tdb->ecode == TDB_ERR_NOEXIST && |
| 3483 | flag == TDB_MODIFY) { |
| 3484 | /* if the record doesn't exist and we are in TDB_MODIFY mode then |
| 3485 | we should fail the store */ |
| 3486 | goto fail; |
| 3487 | } |
| 3488 | } |
| 3489 | /* reset the error code potentially set by the tdb_update() */ |
| 3490 | tdb->ecode = TDB_SUCCESS; |
| 3491 | |
| 3492 | /* delete any existing record - if it doesn't exist we don't |
| 3493 | care. Doing this first reduces fragmentation, and avoids |
| 3494 | coalescing with `allocated' block before it's updated. */ |
| 3495 | if (flag != TDB_INSERT) |
| 3496 | tdb_delete_hash(tdb, key, hash); |
| 3497 | |
| 3498 | /* Copy key+value *before* allocating free space in case malloc |
| 3499 | fails and we are left with a dead spot in the tdb. */ |
| 3500 | |
| 3501 | if (!(p = (char *)malloc(key.dsize + dbuf.dsize))) { |
| 3502 | tdb->ecode = TDB_ERR_OOM; |
| 3503 | goto fail; |
| 3504 | } |
| 3505 | |
| 3506 | memcpy(p, key.dptr, key.dsize); |
| 3507 | if (dbuf.dsize) |
| 3508 | memcpy(p+key.dsize, dbuf.dptr, dbuf.dsize); |
| 3509 | |
| 3510 | if (tdb->max_dead_records != 0) { |
| 3511 | /* |
| 3512 | * Allow for some dead records per hash chain, look if we can |
| 3513 | * find one that can hold the new record. We need enough space |
| 3514 | * for key, data and tailer. If we find one, we don't have to |
| 3515 | * consult the central freelist. |
| 3516 | */ |
| 3517 | rec_ptr = tdb_find_dead( |
| 3518 | tdb, hash, &rec, |
| 3519 | key.dsize + dbuf.dsize + sizeof(tdb_off_t)); |
| 3520 | |
| 3521 | if (rec_ptr != 0) { |
| 3522 | rec.key_len = key.dsize; |
| 3523 | rec.data_len = dbuf.dsize; |
| 3524 | rec.full_hash = hash; |
| 3525 | rec.magic = TDB_MAGIC; |
| 3526 | if (tdb_rec_write(tdb, rec_ptr, &rec) == -1 |
| 3527 | || tdb->methods->tdb_write( |
| 3528 | tdb, rec_ptr + sizeof(rec), |
| 3529 | p, key.dsize + dbuf.dsize) == -1) { |
| 3530 | goto fail; |
| 3531 | } |
| 3532 | goto done; |
| 3533 | } |
| 3534 | } |
| 3535 | |
| 3536 | /* |
| 3537 | * We have to allocate some space from the freelist, so this means we |
| 3538 | * have to lock it. Use the chance to purge all the DEAD records from |
| 3539 | * the hash chain under the freelist lock. |
| 3540 | */ |
| 3541 | |
| 3542 | if (tdb_lock(tdb, -1, F_WRLCK) == -1) { |
| 3543 | goto fail; |
| 3544 | } |
| 3545 | |
| 3546 | if ((tdb->max_dead_records != 0) |
| 3547 | && (tdb_purge_dead(tdb, hash) == -1)) { |
| 3548 | tdb_unlock(tdb, -1, F_WRLCK); |
| 3549 | goto fail; |
| 3550 | } |
| 3551 | |
| 3552 | /* we have to allocate some space */ |
| 3553 | rec_ptr = tdb_allocate(tdb, key.dsize + dbuf.dsize, &rec); |
| 3554 | |
| 3555 | tdb_unlock(tdb, -1, F_WRLCK); |
| 3556 | |
| 3557 | if (rec_ptr == 0) { |
| 3558 | goto fail; |
| 3559 | } |
| 3560 | |
| 3561 | /* Read hash top into next ptr */ |
| 3562 | if (tdb_ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1) |
| 3563 | goto fail; |
| 3564 | |
| 3565 | rec.key_len = key.dsize; |
| 3566 | rec.data_len = dbuf.dsize; |
| 3567 | rec.full_hash = hash; |
| 3568 | rec.magic = TDB_MAGIC; |
| 3569 | |
| 3570 | /* write out and point the top of the hash chain at it */ |
| 3571 | if (tdb_rec_write(tdb, rec_ptr, &rec) == -1 |
| 3572 | || tdb->methods->tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+dbuf.dsize)==-1 |
| 3573 | || tdb_ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) { |
| 3574 | /* Need to tdb_unallocate() here */ |
| 3575 | goto fail; |
| 3576 | } |
| 3577 | |
| 3578 | done: |
| 3579 | ret = 0; |
| 3580 | fail: |
| 3581 | if (ret == 0) { |
| 3582 | tdb_increment_seqnum(tdb); |
| 3583 | } |
| 3584 | |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3585 | SAFE_FREE(p); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3586 | tdb_unlock(tdb, BUCKET(hash), F_WRLCK); |
| 3587 | return ret; |
| 3588 | } |
| 3589 | |
| 3590 | |
| 3591 | /* Append to an entry. Create if not exist. */ |
| 3592 | int tdb_append(struct tdb_context *tdb, TDB_DATA key, TDB_DATA new_dbuf) |
| 3593 | { |
| 3594 | u32 hash; |
| 3595 | TDB_DATA dbuf; |
| 3596 | int ret = -1; |
| 3597 | |
| 3598 | /* find which hash bucket it is in */ |
| 3599 | hash = tdb->hash_fn(&key); |
| 3600 | if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1) |
| 3601 | return -1; |
| 3602 | |
| 3603 | dbuf = tdb_fetch(tdb, key); |
| 3604 | |
| 3605 | if (dbuf.dptr == NULL) { |
| 3606 | dbuf.dptr = (unsigned char *)malloc(new_dbuf.dsize); |
| 3607 | } else { |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 3608 | unsigned char *new_dptr = (unsigned char *)realloc(dbuf.dptr, |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3609 | dbuf.dsize + new_dbuf.dsize); |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 3610 | if (new_dptr == NULL) { |
| 3611 | free(dbuf.dptr); |
| 3612 | } |
| 3613 | dbuf.dptr = new_dptr; |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3614 | } |
| 3615 | |
| 3616 | if (dbuf.dptr == NULL) { |
| 3617 | tdb->ecode = TDB_ERR_OOM; |
| 3618 | goto failed; |
| 3619 | } |
| 3620 | |
| 3621 | memcpy(dbuf.dptr + dbuf.dsize, new_dbuf.dptr, new_dbuf.dsize); |
| 3622 | dbuf.dsize += new_dbuf.dsize; |
| 3623 | |
| 3624 | ret = tdb_store(tdb, key, dbuf, 0); |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3625 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3626 | failed: |
| 3627 | tdb_unlock(tdb, BUCKET(hash), F_WRLCK); |
| 3628 | SAFE_FREE(dbuf.dptr); |
| 3629 | return ret; |
| 3630 | } |
| 3631 | |
| 3632 | |
| 3633 | /* |
| 3634 | return the name of the current tdb file |
| 3635 | useful for external logging functions |
| 3636 | */ |
| 3637 | const char *tdb_name(struct tdb_context *tdb) |
| 3638 | { |
| 3639 | return tdb->name; |
| 3640 | } |
| 3641 | |
| 3642 | /* |
| 3643 | return the underlying file descriptor being used by tdb, or -1 |
| 3644 | useful for external routines that want to check the device/inode |
| 3645 | of the fd |
| 3646 | */ |
| 3647 | int tdb_fd(struct tdb_context *tdb) |
| 3648 | { |
| 3649 | return tdb->fd; |
| 3650 | } |
| 3651 | |
| 3652 | /* |
| 3653 | return the current logging function |
| 3654 | useful for external tdb routines that wish to log tdb errors |
| 3655 | */ |
| 3656 | tdb_log_func tdb_log_fn(struct tdb_context *tdb) |
| 3657 | { |
| 3658 | return tdb->log.log_fn; |
| 3659 | } |
| 3660 | |
| 3661 | |
| 3662 | /* |
| 3663 | get the tdb sequence number. Only makes sense if the writers opened |
| 3664 | with TDB_SEQNUM set. Note that this sequence number will wrap quite |
| 3665 | quickly, so it should only be used for a 'has something changed' |
| 3666 | test, not for code that relies on the count of the number of changes |
| 3667 | made. If you want a counter then use a tdb record. |
| 3668 | |
| 3669 | The aim of this sequence number is to allow for a very lightweight |
| 3670 | test of a possible tdb change. |
| 3671 | */ |
| 3672 | int tdb_get_seqnum(struct tdb_context *tdb) |
| 3673 | { |
| 3674 | tdb_off_t seqnum=0; |
| 3675 | |
| 3676 | tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &seqnum); |
| 3677 | return seqnum; |
| 3678 | } |
| 3679 | |
| 3680 | int tdb_hash_size(struct tdb_context *tdb) |
| 3681 | { |
| 3682 | return tdb->header.hash_size; |
| 3683 | } |
| 3684 | |
| 3685 | size_t tdb_map_size(struct tdb_context *tdb) |
| 3686 | { |
| 3687 | return tdb->map_size; |
| 3688 | } |
| 3689 | |
| 3690 | int tdb_get_flags(struct tdb_context *tdb) |
| 3691 | { |
| 3692 | return tdb->flags; |
| 3693 | } |
| 3694 | |
Theodore Ts'o | 3eed36b | 2008-02-17 06:59:21 -0500 | [diff] [blame] | 3695 | |
| 3696 | /* |
| 3697 | enable sequence number handling on an open tdb |
| 3698 | */ |
| 3699 | void tdb_enable_seqnum(struct tdb_context *tdb) |
| 3700 | { |
| 3701 | tdb->flags |= TDB_SEQNUM; |
| 3702 | } |
| 3703 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3704 | /* file: open.c */ |
| 3705 | |
| 3706 | /* all contexts, to ensure no double-opens (fcntl locks don't nest!) */ |
| 3707 | static struct tdb_context *tdbs = NULL; |
| 3708 | |
| 3709 | |
Theodore Ts'o | 4e523bb | 2011-11-29 11:24:52 -0500 | [diff] [blame] | 3710 | /* This is from a hash algorithm suggested by Rogier Wolff */ |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3711 | static unsigned int default_tdb_hash(TDB_DATA *key) |
| 3712 | { |
| 3713 | u32 value; /* Used to compute the hash value. */ |
| 3714 | u32 i; /* Used to cycle through random values. */ |
| 3715 | |
| 3716 | /* Set the initial value from the key size. */ |
Theodore Ts'o | 4e523bb | 2011-11-29 11:24:52 -0500 | [diff] [blame] | 3717 | for (value = 0, i=0; i < key->dsize; i++) |
| 3718 | value = value * 256 + key->dptr[i] + (value >> 24) * 241; |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3719 | |
Theodore Ts'o | 4e523bb | 2011-11-29 11:24:52 -0500 | [diff] [blame] | 3720 | return value; |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3721 | } |
| 3722 | |
| 3723 | |
| 3724 | /* initialise a new database with a specified hash size */ |
| 3725 | static int tdb_new_database(struct tdb_context *tdb, int hash_size) |
| 3726 | { |
| 3727 | struct tdb_header *newdb; |
| 3728 | int size, ret = -1; |
| 3729 | |
| 3730 | /* We make it up in memory, then write it out if not internal */ |
| 3731 | size = sizeof(struct tdb_header) + (hash_size+1)*sizeof(tdb_off_t); |
| 3732 | if (!(newdb = (struct tdb_header *)calloc(size, 1))) |
| 3733 | return TDB_ERRCODE(TDB_ERR_OOM, -1); |
| 3734 | |
| 3735 | /* Fill in the header */ |
| 3736 | newdb->version = TDB_VERSION; |
| 3737 | newdb->hash_size = hash_size; |
| 3738 | if (tdb->flags & TDB_INTERNAL) { |
| 3739 | tdb->map_size = size; |
| 3740 | tdb->map_ptr = (char *)newdb; |
| 3741 | memcpy(&tdb->header, newdb, sizeof(tdb->header)); |
| 3742 | /* Convert the `ondisk' version if asked. */ |
| 3743 | CONVERT(*newdb); |
| 3744 | return 0; |
| 3745 | } |
| 3746 | if (lseek(tdb->fd, 0, SEEK_SET) == -1) |
| 3747 | goto fail; |
| 3748 | |
| 3749 | if (ftruncate(tdb->fd, 0) == -1) |
| 3750 | goto fail; |
| 3751 | |
| 3752 | /* This creates an endian-converted header, as if read from disk */ |
| 3753 | CONVERT(*newdb); |
| 3754 | memcpy(&tdb->header, newdb, sizeof(tdb->header)); |
| 3755 | /* Don't endian-convert the magic food! */ |
| 3756 | memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1); |
| 3757 | if (write(tdb->fd, newdb, size) != size) { |
| 3758 | ret = -1; |
| 3759 | } else { |
| 3760 | ret = 0; |
| 3761 | } |
| 3762 | |
| 3763 | fail: |
| 3764 | SAFE_FREE(newdb); |
| 3765 | return ret; |
| 3766 | } |
| 3767 | |
| 3768 | |
| 3769 | |
| 3770 | static int tdb_already_open(dev_t device, |
| 3771 | ino_t ino) |
| 3772 | { |
| 3773 | struct tdb_context *i; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3774 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3775 | for (i = tdbs; i; i = i->next) { |
| 3776 | if (i->device == device && i->inode == ino) { |
| 3777 | return 1; |
| 3778 | } |
| 3779 | } |
| 3780 | |
| 3781 | return 0; |
| 3782 | } |
| 3783 | |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3784 | /* open the database, creating it if necessary |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3785 | |
| 3786 | The open_flags and mode are passed straight to the open call on the |
| 3787 | database file. A flags value of O_WRONLY is invalid. The hash size |
| 3788 | is advisory, use zero for a default value. |
| 3789 | |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3790 | Return is NULL on error, in which case errno is also set. Don't |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3791 | try to call tdb_error or tdb_errname, just do strerror(errno). |
| 3792 | |
| 3793 | @param name may be NULL for internal databases. */ |
| 3794 | struct tdb_context *tdb_open(const char *name, int hash_size, int tdb_flags, |
| 3795 | int open_flags, mode_t mode) |
| 3796 | { |
| 3797 | return tdb_open_ex(name, hash_size, tdb_flags, open_flags, mode, NULL, NULL); |
| 3798 | } |
| 3799 | |
| 3800 | /* a default logging function */ |
| 3801 | static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...) PRINTF_ATTRIBUTE(3, 4); |
| 3802 | static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...) |
| 3803 | { |
| 3804 | } |
| 3805 | |
| 3806 | |
| 3807 | struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags, |
| 3808 | int open_flags, mode_t mode, |
| 3809 | const struct tdb_logging_context *log_ctx, |
| 3810 | tdb_hash_func hash_fn) |
| 3811 | { |
| 3812 | struct tdb_context *tdb; |
| 3813 | struct stat st; |
| 3814 | int rev = 0, locked = 0; |
| 3815 | unsigned char *vp; |
| 3816 | u32 vertest; |
| 3817 | |
| 3818 | if (!(tdb = (struct tdb_context *)calloc(1, sizeof *tdb))) { |
| 3819 | /* Can't log this */ |
| 3820 | errno = ENOMEM; |
| 3821 | goto fail; |
| 3822 | } |
| 3823 | tdb_io_init(tdb); |
| 3824 | tdb->fd = -1; |
| 3825 | tdb->name = NULL; |
| 3826 | tdb->map_ptr = NULL; |
| 3827 | tdb->flags = tdb_flags; |
| 3828 | tdb->open_flags = open_flags; |
| 3829 | if (log_ctx) { |
| 3830 | tdb->log = *log_ctx; |
| 3831 | } else { |
| 3832 | tdb->log.log_fn = null_log_fn; |
| 3833 | tdb->log.log_private = NULL; |
| 3834 | } |
| 3835 | tdb->hash_fn = hash_fn ? hash_fn : default_tdb_hash; |
| 3836 | |
| 3837 | /* cache the page size */ |
Mike Frysinger | 24d364f | 2012-01-09 21:19:48 -0500 | [diff] [blame] | 3838 | tdb->page_size = sysconf(_SC_PAGESIZE); |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3839 | if (tdb->page_size <= 0) { |
| 3840 | tdb->page_size = 0x2000; |
| 3841 | } |
| 3842 | |
| 3843 | if ((open_flags & O_ACCMODE) == O_WRONLY) { |
| 3844 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: can't open tdb %s write-only\n", |
| 3845 | name)); |
| 3846 | errno = EINVAL; |
| 3847 | goto fail; |
| 3848 | } |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3849 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3850 | if (hash_size == 0) |
| 3851 | hash_size = DEFAULT_HASH_SIZE; |
| 3852 | if ((open_flags & O_ACCMODE) == O_RDONLY) { |
| 3853 | tdb->read_only = 1; |
| 3854 | /* read only databases don't do locking or clear if first */ |
| 3855 | tdb->flags |= TDB_NOLOCK; |
| 3856 | tdb->flags &= ~TDB_CLEAR_IF_FIRST; |
| 3857 | } |
| 3858 | |
| 3859 | /* internal databases don't mmap or lock, and start off cleared */ |
| 3860 | if (tdb->flags & TDB_INTERNAL) { |
| 3861 | tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP); |
| 3862 | tdb->flags &= ~TDB_CLEAR_IF_FIRST; |
| 3863 | if (tdb_new_database(tdb, hash_size) != 0) { |
| 3864 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: tdb_new_database failed!")); |
| 3865 | goto fail; |
| 3866 | } |
| 3867 | goto internal; |
| 3868 | } |
| 3869 | |
| 3870 | if ((tdb->fd = open(name, open_flags, mode)) == -1) { |
| 3871 | TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_open_ex: could not open file %s: %s\n", |
| 3872 | name, strerror(errno))); |
| 3873 | goto fail; /* errno set by open(2) */ |
| 3874 | } |
| 3875 | |
| 3876 | /* ensure there is only one process initialising at once */ |
| 3877 | if (tdb->methods->tdb_brlock(tdb, GLOBAL_LOCK, F_WRLCK, F_SETLKW, 0, 1) == -1) { |
| 3878 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to get global lock on %s: %s\n", |
| 3879 | name, strerror(errno))); |
| 3880 | goto fail; /* errno set by tdb_brlock */ |
| 3881 | } |
| 3882 | |
| 3883 | /* we need to zero database if we are the only one with it open */ |
| 3884 | if ((tdb_flags & TDB_CLEAR_IF_FIRST) && |
| 3885 | (locked = (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0, 1) == 0))) { |
| 3886 | open_flags |= O_CREAT; |
| 3887 | if (ftruncate(tdb->fd, 0) == -1) { |
| 3888 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: " |
| 3889 | "failed to truncate %s: %s\n", |
| 3890 | name, strerror(errno))); |
| 3891 | goto fail; /* errno set by ftruncate */ |
| 3892 | } |
| 3893 | } |
| 3894 | |
| 3895 | if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header) |
| 3896 | || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0 |
| 3897 | || (tdb->header.version != TDB_VERSION |
| 3898 | && !(rev = (tdb->header.version==TDB_BYTEREV(TDB_VERSION))))) { |
| 3899 | /* its not a valid database - possibly initialise it */ |
| 3900 | if (!(open_flags & O_CREAT) || tdb_new_database(tdb, hash_size) == -1) { |
| 3901 | errno = EIO; /* ie bad format or something */ |
| 3902 | goto fail; |
| 3903 | } |
| 3904 | rev = (tdb->flags & TDB_CONVERT); |
| 3905 | } |
| 3906 | vp = (unsigned char *)&tdb->header.version; |
| 3907 | vertest = (((u32)vp[0]) << 24) | (((u32)vp[1]) << 16) | |
| 3908 | (((u32)vp[2]) << 8) | (u32)vp[3]; |
| 3909 | tdb->flags |= (vertest==TDB_VERSION) ? TDB_BIGENDIAN : 0; |
| 3910 | if (!rev) |
| 3911 | tdb->flags &= ~TDB_CONVERT; |
| 3912 | else { |
| 3913 | tdb->flags |= TDB_CONVERT; |
| 3914 | tdb_convert(&tdb->header, sizeof(tdb->header)); |
| 3915 | } |
| 3916 | if (fstat(tdb->fd, &st) == -1) |
| 3917 | goto fail; |
| 3918 | |
| 3919 | if (tdb->header.rwlocks != 0) { |
| 3920 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: spinlocks no longer supported\n")); |
| 3921 | goto fail; |
| 3922 | } |
| 3923 | |
| 3924 | /* Is it already in the open list? If so, fail. */ |
| 3925 | if (tdb_already_open(st.st_dev, st.st_ino)) { |
| 3926 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: " |
| 3927 | "%s (%d,%d) is already open in this process\n", |
| 3928 | name, (int)st.st_dev, (int)st.st_ino)); |
| 3929 | errno = EBUSY; |
| 3930 | goto fail; |
| 3931 | } |
| 3932 | |
| 3933 | if (!(tdb->name = (char *)strdup(name))) { |
| 3934 | errno = ENOMEM; |
| 3935 | goto fail; |
| 3936 | } |
| 3937 | |
| 3938 | tdb->map_size = st.st_size; |
| 3939 | tdb->device = st.st_dev; |
| 3940 | tdb->inode = st.st_ino; |
| 3941 | tdb->max_dead_records = 0; |
| 3942 | tdb_mmap(tdb); |
| 3943 | if (locked) { |
| 3944 | if (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK, 0, 1) == -1) { |
| 3945 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: " |
| 3946 | "failed to take ACTIVE_LOCK on %s: %s\n", |
| 3947 | name, strerror(errno))); |
| 3948 | goto fail; |
| 3949 | } |
| 3950 | |
| 3951 | } |
| 3952 | |
| 3953 | /* We always need to do this if the CLEAR_IF_FIRST flag is set, even if |
| 3954 | we didn't get the initial exclusive lock as we need to let all other |
| 3955 | users know we're using it. */ |
| 3956 | |
| 3957 | if (tdb_flags & TDB_CLEAR_IF_FIRST) { |
| 3958 | /* leave this lock in place to indicate it's in use */ |
| 3959 | if (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0, 1) == -1) |
| 3960 | goto fail; |
| 3961 | } |
| 3962 | |
| 3963 | /* if needed, run recovery */ |
| 3964 | if (tdb_transaction_recover(tdb) == -1) { |
| 3965 | goto fail; |
| 3966 | } |
| 3967 | |
| 3968 | internal: |
| 3969 | /* Internal (memory-only) databases skip all the code above to |
| 3970 | * do with disk files, and resume here by releasing their |
| 3971 | * global lock and hooking into the active list. */ |
| 3972 | if (tdb->methods->tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0, 1) == -1) |
| 3973 | goto fail; |
| 3974 | tdb->next = tdbs; |
| 3975 | tdbs = tdb; |
| 3976 | return tdb; |
| 3977 | |
| 3978 | fail: |
| 3979 | { int save_errno = errno; |
| 3980 | |
| 3981 | if (!tdb) |
| 3982 | return NULL; |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 3983 | |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 3984 | if (tdb->map_ptr) { |
| 3985 | if (tdb->flags & TDB_INTERNAL) |
| 3986 | SAFE_FREE(tdb->map_ptr); |
| 3987 | else |
| 3988 | tdb_munmap(tdb); |
| 3989 | } |
| 3990 | SAFE_FREE(tdb->name); |
| 3991 | if (tdb->fd != -1) |
| 3992 | if (close(tdb->fd) != 0) |
| 3993 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to close tdb->fd on error!\n")); |
| 3994 | SAFE_FREE(tdb); |
| 3995 | errno = save_errno; |
| 3996 | return NULL; |
| 3997 | } |
| 3998 | } |
| 3999 | |
| 4000 | /* |
| 4001 | * Set the maximum number of dead records per hash chain |
| 4002 | */ |
| 4003 | |
| 4004 | void tdb_set_max_dead(struct tdb_context *tdb, int max_dead) |
| 4005 | { |
| 4006 | tdb->max_dead_records = max_dead; |
| 4007 | } |
| 4008 | |
| 4009 | /** |
| 4010 | * Close a database. |
| 4011 | * |
| 4012 | * @returns -1 for error; 0 for success. |
| 4013 | **/ |
| 4014 | int tdb_close(struct tdb_context *tdb) |
| 4015 | { |
| 4016 | struct tdb_context **i; |
| 4017 | int ret = 0; |
| 4018 | |
| 4019 | if (tdb->transaction) { |
| 4020 | tdb_transaction_cancel(tdb); |
| 4021 | } |
| 4022 | |
| 4023 | if (tdb->map_ptr) { |
| 4024 | if (tdb->flags & TDB_INTERNAL) |
| 4025 | SAFE_FREE(tdb->map_ptr); |
| 4026 | else |
| 4027 | tdb_munmap(tdb); |
| 4028 | } |
| 4029 | SAFE_FREE(tdb->name); |
| 4030 | if (tdb->fd != -1) |
| 4031 | ret = close(tdb->fd); |
| 4032 | SAFE_FREE(tdb->lockrecs); |
| 4033 | |
| 4034 | /* Remove from contexts list */ |
| 4035 | for (i = &tdbs; *i; i = &(*i)->next) { |
| 4036 | if (*i == tdb) { |
| 4037 | *i = tdb->next; |
| 4038 | break; |
| 4039 | } |
| 4040 | } |
| 4041 | |
| 4042 | memset(tdb, 0, sizeof(*tdb)); |
| 4043 | SAFE_FREE(tdb); |
| 4044 | |
| 4045 | return ret; |
| 4046 | } |
| 4047 | |
| 4048 | /* register a loging function */ |
| 4049 | void tdb_set_logging_function(struct tdb_context *tdb, |
| 4050 | const struct tdb_logging_context *log_ctx) |
| 4051 | { |
| 4052 | tdb->log = *log_ctx; |
| 4053 | } |
| 4054 | |
| 4055 | void *tdb_get_logging_private(struct tdb_context *tdb) |
| 4056 | { |
| 4057 | return tdb->log.log_private; |
| 4058 | } |
| 4059 | |
| 4060 | /* reopen a tdb - this can be used after a fork to ensure that we have an independent |
| 4061 | seek pointer from our parent and to re-establish locks */ |
| 4062 | int tdb_reopen(struct tdb_context *tdb) |
| 4063 | { |
| 4064 | struct stat st; |
| 4065 | |
| 4066 | if (tdb->flags & TDB_INTERNAL) { |
| 4067 | return 0; /* Nothing to do. */ |
| 4068 | } |
| 4069 | |
| 4070 | if (tdb->num_locks != 0 || tdb->global_lock.count) { |
| 4071 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed with locks held\n")); |
| 4072 | goto fail; |
| 4073 | } |
| 4074 | |
| 4075 | if (tdb->transaction != 0) { |
| 4076 | TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed inside a transaction\n")); |
| 4077 | goto fail; |
| 4078 | } |
| 4079 | |
| 4080 | if (tdb_munmap(tdb) != 0) { |
| 4081 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: munmap failed (%s)\n", strerror(errno))); |
| 4082 | goto fail; |
| 4083 | } |
| 4084 | if (close(tdb->fd) != 0) |
| 4085 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: WARNING closing tdb->fd failed!\n")); |
| 4086 | tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0); |
| 4087 | if (tdb->fd == -1) { |
| 4088 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: open failed (%s)\n", strerror(errno))); |
| 4089 | goto fail; |
| 4090 | } |
Theodore Ts'o | efc6f62 | 2008-08-27 23:07:54 -0400 | [diff] [blame] | 4091 | if ((tdb->flags & TDB_CLEAR_IF_FIRST) && |
Theodore Ts'o | 106ad96 | 2007-04-04 21:26:37 -0400 | [diff] [blame] | 4092 | (tdb->methods->tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0, 1) == -1)) { |
| 4093 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: failed to obtain active lock\n")); |
| 4094 | goto fail; |
| 4095 | } |
| 4096 | if (fstat(tdb->fd, &st) != 0) { |
| 4097 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: fstat failed (%s)\n", strerror(errno))); |
| 4098 | goto fail; |
| 4099 | } |
| 4100 | if (st.st_ino != tdb->inode || st.st_dev != tdb->device) { |
| 4101 | TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: file dev/inode has changed!\n")); |
| 4102 | goto fail; |
| 4103 | } |
| 4104 | tdb_mmap(tdb); |
| 4105 | |
| 4106 | return 0; |
| 4107 | |
| 4108 | fail: |
| 4109 | tdb_close(tdb); |
| 4110 | return -1; |
| 4111 | } |
| 4112 | |
| 4113 | /* reopen all tdb's */ |
| 4114 | int tdb_reopen_all(int parent_longlived) |
| 4115 | { |
| 4116 | struct tdb_context *tdb; |
| 4117 | |
| 4118 | for (tdb=tdbs; tdb; tdb = tdb->next) { |
| 4119 | /* |
| 4120 | * If the parent is longlived (ie. a |
| 4121 | * parent daemon architecture), we know |
| 4122 | * it will keep it's active lock on a |
| 4123 | * tdb opened with CLEAR_IF_FIRST. Thus |
| 4124 | * for child processes we don't have to |
| 4125 | * add an active lock. This is essential |
| 4126 | * to improve performance on systems that |
| 4127 | * keep POSIX locks as a non-scalable data |
| 4128 | * structure in the kernel. |
| 4129 | */ |
| 4130 | if (parent_longlived) { |
| 4131 | /* Ensure no clear-if-first. */ |
| 4132 | tdb->flags &= ~TDB_CLEAR_IF_FIRST; |
| 4133 | } |
| 4134 | |
| 4135 | if (tdb_reopen(tdb) != 0) |
| 4136 | return -1; |
| 4137 | } |
| 4138 | |
| 4139 | return 0; |
| 4140 | } |