/*- * See the file LICENSE for redistribution information. * * Copyright (c) 1996, 1997, 1998 * Sleepycat Software. All rights reserved. */ #include "config.h" #ifndef lint static const char sccsid[] = "@(#)log_put.c 10.44 (Sleepycat) 11/3/98"; #endif /* not lint */ #ifndef NO_SYSTEM_INCLUDES #include #include #include #include #include #include #endif #include "db_int.h" #include "shqueue.h" #include "db_page.h" #include "log.h" #include "hash.h" #include "clib_ext.h" #include "common_ext.h" static int __log_fill __P((DB_LOG *, DB_LSN *, void *, u_int32_t)); static int __log_flush __P((DB_LOG *, const DB_LSN *)); static int __log_newfd __P((DB_LOG *)); static int __log_putr __P((DB_LOG *, DB_LSN *, const DBT *, u_int32_t)); static int __log_write __P((DB_LOG *, void *, u_int32_t)); /* * log_put -- * Write a log record. */ int log_put(dblp, lsn, dbt, flags) DB_LOG *dblp; DB_LSN *lsn; const DBT *dbt; u_int32_t flags; { int ret; LOG_PANIC_CHECK(dblp); /* Validate arguments. */ if (flags != 0 && flags != DB_CHECKPOINT && flags != DB_CURLSN && flags != DB_FLUSH) return (__db_ferr(dblp->dbenv, "log_put", 0)); LOCK_LOGREGION(dblp); ret = __log_put(dblp, lsn, dbt, flags); UNLOCK_LOGREGION(dblp); return (ret); } /* * __log_put -- * Write a log record; internal version. * * PUBLIC: int __log_put __P((DB_LOG *, DB_LSN *, const DBT *, u_int32_t)); */ int __log_put(dblp, lsn, dbt, flags) DB_LOG *dblp; DB_LSN *lsn; const DBT *dbt; u_int32_t flags; { DBT fid_dbt, t; DB_LSN r_unused; FNAME *fnp; LOG *lp; u_int32_t lastoff; int ret; lp = dblp->lp; /* * If the application just wants to know where we are, fill in * the information. Currently used by the transaction manager * to avoid writing TXN_begin records. */ if (flags == DB_CURLSN) { lsn->file = lp->lsn.file; lsn->offset = lp->lsn.offset; return (0); } /* If this information won't fit in the file, swap files. */ if (lp->lsn.offset + sizeof(HDR) + dbt->size > lp->persist.lg_max) { if (sizeof(HDR) + sizeof(LOGP) + dbt->size > lp->persist.lg_max) { __db_err(dblp->dbenv, "log_put: record larger than maximum file size"); return (EINVAL); } /* Flush the log. */ if ((ret = __log_flush(dblp, NULL)) != 0) return (ret); /* * Save the last known offset from the previous file, we'll * need it to initialize the persistent header information. */ lastoff = lp->lsn.offset; /* Point the current LSN to the new file. */ ++lp->lsn.file; lp->lsn.offset = 0; /* Reset the file write offset. */ lp->w_off = 0; } else lastoff = 0; /* Initialize the LSN information returned to the user. */ lsn->file = lp->lsn.file; lsn->offset = lp->lsn.offset; /* * Insert persistent information as the first record in every file. * Note that the previous length is wrong for the very first record * of the log, but that's okay, we check for it during retrieval. */ if (lp->lsn.offset == 0) { t.data = &lp->persist; t.size = sizeof(LOGP); if ((ret = __log_putr(dblp, lsn, &t, lastoff == 0 ? 0 : lastoff - lp->len)) != 0) return (ret); /* Update the LSN information returned to the user. */ lsn->file = lp->lsn.file; lsn->offset = lp->lsn.offset; } /* Write the application's log record. */ if ((ret = __log_putr(dblp, lsn, dbt, lp->lsn.offset - lp->len)) != 0) return (ret); /* * On a checkpoint, we: * Put out the checkpoint record (above). * Save the LSN of the checkpoint in the shared region. * Append the set of file name information into the log. */ if (flags == DB_CHECKPOINT) { lp->chkpt_lsn = *lsn; for (fnp = SH_TAILQ_FIRST(&dblp->lp->fq, __fname); fnp != NULL; fnp = SH_TAILQ_NEXT(fnp, q, __fname)) { if (fnp->ref == 0) /* Entry not in use. */ continue; memset(&t, 0, sizeof(t)); t.data = R_ADDR(dblp, fnp->name_off); t.size = strlen(t.data) + 1; memset(&fid_dbt, 0, sizeof(fid_dbt)); fid_dbt.data = fnp->ufid; fid_dbt.size = DB_FILE_ID_LEN; if ((ret = __log_register_log(dblp, NULL, &r_unused, 0, LOG_CHECKPOINT, &t, &fid_dbt, fnp->id, fnp->s_type)) != 0) return (ret); } } /* * On a checkpoint or when flush is requested, we: * Flush the current buffer contents to disk. * Sync the log to disk. */ if (flags == DB_FLUSH || flags == DB_CHECKPOINT) if ((ret = __log_flush(dblp, NULL)) != 0) return (ret); /* * On a checkpoint, we: * Save the time the checkpoint was written. * Reset the bytes written since the last checkpoint. */ if (flags == DB_CHECKPOINT) { (void)time(&lp->chkpt); lp->stat.st_wc_bytes = lp->stat.st_wc_mbytes = 0; } return (0); } /* * __log_putr -- * Actually put a record into the log. */ static int __log_putr(dblp, lsn, dbt, prev) DB_LOG *dblp; DB_LSN *lsn; const DBT *dbt; u_int32_t prev; { HDR hdr; LOG *lp; int ret; lp = dblp->lp; /* * Initialize the header. If we just switched files, lsn.offset will * be 0, and what we really want is the offset of the previous record * in the previous file. Fortunately, prev holds the value we want. */ hdr.prev = prev; hdr.len = sizeof(HDR) + dbt->size; hdr.cksum = __ham_func4(dbt->data, dbt->size); if ((ret = __log_fill(dblp, lsn, &hdr, sizeof(HDR))) != 0) return (ret); lp->len = sizeof(HDR); lp->lsn.offset += sizeof(HDR); if ((ret = __log_fill(dblp, lsn, dbt->data, dbt->size)) != 0) return (ret); lp->len += dbt->size; lp->lsn.offset += dbt->size; return (0); } /* * log_flush -- * Write all records less than or equal to the specified LSN. */ int log_flush(dblp, lsn) DB_LOG *dblp; const DB_LSN *lsn; { int ret; LOG_PANIC_CHECK(dblp); LOCK_LOGREGION(dblp); ret = __log_flush(dblp, lsn); UNLOCK_LOGREGION(dblp); return (ret); } /* * __log_flush -- * Write all records less than or equal to the specified LSN; internal * version. */ static int __log_flush(dblp, lsn) DB_LOG *dblp; const DB_LSN *lsn; { DB_LSN t_lsn; LOG *lp; int current, ret; ret = 0; lp = dblp->lp; /* * If no LSN specified, flush the entire log by setting the flush LSN * to the last LSN written in the log. Otherwise, check that the LSN * isn't a non-existent record for the log. */ if (lsn == NULL) { t_lsn.file = lp->lsn.file; t_lsn.offset = lp->lsn.offset - lp->len; lsn = &t_lsn; } else if (lsn->file > lp->lsn.file || (lsn->file == lp->lsn.file && lsn->offset > lp->lsn.offset - lp->len)) { __db_err(dblp->dbenv, "log_flush: LSN past current end-of-log"); return (EINVAL); } /* * If the LSN is less than the last-sync'd LSN, we're done. Note, * the last-sync LSN saved in s_lsn is the LSN of the first byte * we absolutely know has been written to disk, so the test is <=. */ if (lsn->file < lp->s_lsn.file || (lsn->file == lp->s_lsn.file && lsn->offset <= lp->s_lsn.offset)) return (0); /* * We may need to write the current buffer. We have to write the * current buffer if the flush LSN is greater than or equal to the * buffer's starting LSN. */ current = 0; if (lp->b_off != 0 && log_compare(lsn, &lp->f_lsn) >= 0) { if ((ret = __log_write(dblp, lp->buf, lp->b_off)) != 0) return (ret); lp->b_off = 0; current = 1; } /* * It's possible that this thread may never have written to this log * file. Acquire a file descriptor if we don't already have one. */ if (dblp->lfname != dblp->lp->lsn.file) if ((ret = __log_newfd(dblp)) != 0) return (ret); /* Sync all writes to disk. */ if ((ret = __os_fsync(dblp->lfd)) != 0) { __db_panic(dblp->dbenv, ret); return (ret); } ++lp->stat.st_scount; /* * Set the last-synced LSN, using the LSN of the current buffer. If * the current buffer was flushed, we know the LSN of the first byte * of the buffer is on disk, otherwise, we only know that the LSN of * the record before the one beginning the current buffer is on disk. * * XXX * Check to make sure that the saved lsn isn't 0 before we go making * this change. If DB_CHECKPOINT was called before we actually wrote * something, you can end up here without ever having written anything * to a log file, and decrementing either s_lsn.file or s_lsn.offset * will cause much sadness later on. */ lp->s_lsn = lp->f_lsn; if (!current && lp->s_lsn.file != 0) if (lp->s_lsn.offset == 0) { --lp->s_lsn.file; lp->s_lsn.offset = lp->persist.lg_max; } else --lp->s_lsn.offset; return (0); } /* * __log_fill -- * Write information into the log. */ static int __log_fill(dblp, lsn, addr, len) DB_LOG *dblp; DB_LSN *lsn; void *addr; u_int32_t len; { LOG *lp; u_int32_t nrec; size_t nw, remain; int ret; /* Copy out the data. */ for (lp = dblp->lp; len > 0;) { /* * If we're beginning a new buffer, note the user LSN to which * the first byte of the buffer belongs. We have to know this * when flushing the buffer so that we know if the in-memory * buffer needs to be flushed. */ if (lp->b_off == 0) lp->f_lsn = *lsn; /* * If we're on a buffer boundary and the data is big enough, * copy as many records as we can directly from the data. */ if (lp->b_off == 0 && len >= sizeof(lp->buf)) { nrec = len / sizeof(lp->buf); if ((ret = __log_write(dblp, addr, nrec * sizeof(lp->buf))) != 0) return (ret); addr = (u_int8_t *)addr + nrec * sizeof(lp->buf); len -= nrec * sizeof(lp->buf); continue; } /* Figure out how many bytes we can copy this time. */ remain = sizeof(lp->buf) - lp->b_off; nw = remain > len ? len : remain; memcpy(lp->buf + lp->b_off, addr, nw); addr = (u_int8_t *)addr + nw; len -= nw; lp->b_off += nw; /* If we fill the buffer, flush it. */ if (lp->b_off == sizeof(lp->buf)) { if ((ret = __log_write(dblp, lp->buf, sizeof(lp->buf))) != 0) return (ret); lp->b_off = 0; } } return (0); } /* * __log_write -- * Write the log buffer to disk. */ static int __log_write(dblp, addr, len) DB_LOG *dblp; void *addr; u_int32_t len; { LOG *lp; ssize_t nw; int ret; /* * If we haven't opened the log file yet or the current one * has changed, acquire a new log file. */ lp = dblp->lp; if (dblp->lfd == -1 || dblp->lfname != lp->lsn.file) if ((ret = __log_newfd(dblp)) != 0) return (ret); /* * Seek to the offset in the file (someone may have written it * since we last did). */ if ((ret = __os_seek(dblp->lfd, 0, 0, lp->w_off, 0, SEEK_SET)) != 0 || (ret = __os_write(dblp->lfd, addr, len, &nw)) != 0) { __db_panic(dblp->dbenv, ret); return (ret); } if (nw != (int32_t)len) return (EIO); /* Reset the buffer offset and update the seek offset. */ lp->w_off += len; /* Update written statistics. */ if ((lp->stat.st_w_bytes += len) >= MEGABYTE) { lp->stat.st_w_bytes -= MEGABYTE; ++lp->stat.st_w_mbytes; } if ((lp->stat.st_wc_bytes += len) >= MEGABYTE) { lp->stat.st_wc_bytes -= MEGABYTE; ++lp->stat.st_wc_mbytes; } ++lp->stat.st_wcount; return (0); } /* * log_file -- * Map a DB_LSN to a file name. */ int log_file(dblp, lsn, namep, len) DB_LOG *dblp; const DB_LSN *lsn; char *namep; size_t len; { int ret; char *name; LOG_PANIC_CHECK(dblp); LOCK_LOGREGION(dblp); ret = __log_name(dblp, lsn->file, &name, NULL, 0); UNLOCK_LOGREGION(dblp); if (ret != 0) return (ret); /* Check to make sure there's enough room and copy the name. */ if (len < strlen(name) + 1) { *namep = '\0'; return (ENOMEM); } (void)strcpy(namep, name); __os_freestr(name); return (0); } /* * __log_newfd -- * Acquire a file descriptor for the current log file. */ static int __log_newfd(dblp) DB_LOG *dblp; { int ret; char *name; /* Close any previous file descriptor. */ if (dblp->lfd != -1) { (void)__os_close(dblp->lfd); dblp->lfd = -1; } /* Get the path of the new file and open it. */ dblp->lfname = dblp->lp->lsn.file; if ((ret = __log_name(dblp, dblp->lfname, &name, &dblp->lfd, DB_CREATE | DB_SEQUENTIAL)) != 0) __db_err(dblp->dbenv, "log_put: %s: %s", name, strerror(ret)); __os_freestr(name); return (ret); } /* * __log_name -- * Return the log name for a particular file, and optionally open it. * * PUBLIC: int __log_name __P((DB_LOG *, u_int32_t, char **, int *, u_int32_t)); */ int __log_name(dblp, filenumber, namep, fdp, flags) DB_LOG *dblp; u_int32_t filenumber, flags; char **namep; int *fdp; { int ret; char *oname; char old[sizeof(LFPREFIX) + 5 + 20], new[sizeof(LFPREFIX) + 10 + 20]; /* * !!! * The semantics of this routine are bizarre. * * The reason for all of this is that we need a place where we can * intercept requests for log files, and, if appropriate, check for * both the old-style and new-style log file names. The trick is * that all callers of this routine that are opening the log file * read-only want to use an old-style file name if they can't find * a match using a new-style name. The only down-side is that some * callers may check for the old-style when they really don't need * to, but that shouldn't mess up anything, and we only check for * the old-style name when we've already failed to find a new-style * one. * * Create a new-style file name, and if we're not going to open the * file, return regardless. */ (void)snprintf(new, sizeof(new), LFNAME, filenumber); if ((ret = __db_appname(dblp->dbenv, DB_APP_LOG, dblp->dir, new, 0, NULL, namep)) != 0 || fdp == NULL) return (ret); /* Open the new-style file -- if we succeed, we're done. */ if ((ret = __db_open(*namep, flags, flags, dblp->lp->persist.mode, fdp)) == 0) return (0); /* * The open failed... if the DB_RDONLY flag isn't set, we're done, * the caller isn't interested in old-style files. */ if (!LF_ISSET(DB_RDONLY)) return (ret); /* Create an old-style file name. */ (void)snprintf(old, sizeof(old), LFNAME_V1, filenumber); if ((ret = __db_appname(dblp->dbenv, DB_APP_LOG, dblp->dir, old, 0, NULL, &oname)) != 0) goto err; /* * Open the old-style file -- if we succeed, we're done. Free the * space allocated for the new-style name and return the old-style * name to the caller. */ if ((ret = __db_open(oname, flags, flags, dblp->lp->persist.mode, fdp)) == 0) { __os_freestr(*namep); *namep = oname; return (0); } /* * Couldn't find either style of name -- return the new-style name * for the caller's error message. If it's an old-style name that's * actually missing we're going to confuse the user with the error * message, but that implies that not only were we looking for an * old-style name, but we expected it to exist and we weren't just * looking for any log file. That's not a likely error. */ err: __os_freestr(oname); return (ret); }