From 4c185a6077322ba64231d23dda25a6b6d44d0b12 Mon Sep 17 00:00:00 2001 From: Volker Lendecke Date: Thu, 10 May 2007 10:42:13 +0000 Subject: r22775: For the cluster code I've developed a wrapper around tdb to put different database backends in place dynamically. The main abstractions are db_context and db_record, it should be mainly self-describing, see include/dbwrap.h. You open the db just as you would open a tdb, this time with db_open(). If you want to fetch a record, just do the db->fetch() call, if you want to do operations on it, you need to get it with fetch_locked(). I added dbwrap_file.c (not heavily tested lately) as an example for what can be done with that abstraction, uses a file per key. So if anybody is willing to shape that up, we might have a chance on reiserfs again.... :-) This abstraction works fine for brlock.tdb, locking.tdb, connections.tdb and sessionid.tdb. It should work fine for the others as well, I just did not yet get around to convert them. If nobody loudly screams NO, then I will import the code that uses this soon. Volker (This used to be commit e9d7484ca246cfca4a1fd23be35edc2783136ebe) --- source3/lib/dbwrap.c | 61 +++++++ source3/lib/dbwrap_file.c | 413 ++++++++++++++++++++++++++++++++++++++++++++++ source3/lib/dbwrap_tdb.c | 227 +++++++++++++++++++++++++ 3 files changed, 701 insertions(+) create mode 100644 source3/lib/dbwrap.c create mode 100644 source3/lib/dbwrap_file.c create mode 100644 source3/lib/dbwrap_tdb.c (limited to 'source3/lib') diff --git a/source3/lib/dbwrap.c b/source3/lib/dbwrap.c new file mode 100644 index 0000000000..9f74a9eb48 --- /dev/null +++ b/source3/lib/dbwrap.c @@ -0,0 +1,61 @@ +/* + Unix SMB/CIFS implementation. + Database interface wrapper + Copyright (C) Jim McDonough 2006 + + Major code contributions from Aleksey Fedoseev (fedoseev@ru.ibm.com) + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ + +#include "includes.h" + +/* + * Fall back using fetch_locked if no genuine fetch operation is provided + */ + +static int dbwrap_fallback_fetch(struct db_context *db, TALLOC_CTX *mem_ctx, + TDB_DATA key, TDB_DATA *data) +{ + struct db_record *rec; + + if (!(rec = db->fetch_locked(db, mem_ctx, key))) { + return -1; + } + + data->dsize = rec->value.dsize; + data->dptr = talloc_move(mem_ctx, &rec->value.dptr); + TALLOC_FREE(rec); + return 0; +} + +struct db_context *db_open(TALLOC_CTX *mem_ctx, + const char *name, + int hash_size, int tdb_flags, + int open_flags, mode_t mode) +{ + struct db_context *result = NULL; + + if (result == NULL) { + result = db_open_tdb(mem_ctx, name, hash_size, + tdb_flags, open_flags, mode); + } + + if ((result != NULL) && (result->fetch == NULL)) { + result->fetch = dbwrap_fallback_fetch; + } + + return result; +} diff --git a/source3/lib/dbwrap_file.c b/source3/lib/dbwrap_file.c new file mode 100644 index 0000000000..9e18c6b8fe --- /dev/null +++ b/source3/lib/dbwrap_file.c @@ -0,0 +1,413 @@ +/* + Unix SMB/CIFS implementation. + Database interface using a file per record + Copyright (C) Volker Lendecke 2005 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ + +/* + * Be aware that this is just sample code that has not seen too much testing + */ + +#include "includes.h" + +struct db_file_ctx { + const char *dirname; + + /* We only support one locked record at a time -- everything else + * would lead to a potential deadlock anyway! */ + struct db_record *locked_record; +}; + +struct db_locked_file { + int fd; + uint8 hash; + const char *name; + const char *path; + struct db_file_ctx *parent; +}; + +/* Copy from statcache.c... */ + +static uint32 fsh(const uint8 *p, int len) +{ + uint32 n = 0; + int i; + for (i=0; iparent != NULL) { + data->parent->locked_record = NULL; + } + + if (close(data->fd) != 0) { + DEBUG(3, ("close failed: %s\n", strerror(errno))); + return -1; + } + + return 0; +} + +static NTSTATUS db_file_store(struct db_record *rec, TDB_DATA data, int flag); +static NTSTATUS db_file_delete(struct db_record *rec); + +static struct db_record *db_file_fetch_locked(struct db_context *db, + TALLOC_CTX *mem_ctx, + TDB_DATA key) +{ + struct db_file_ctx *ctx = talloc_get_type_abort(db->private_data, + struct db_file_ctx); + struct db_record *result; + struct db_locked_file *file; + struct flock fl; + SMB_STRUCT_STAT statbuf; + ssize_t nread; + int ret; + + SMB_ASSERT(ctx->locked_record == NULL); + + again: + if (!(result = TALLOC_P(mem_ctx, struct db_record))) { + DEBUG(0, ("talloc failed\n")); + return NULL; + } + + if (!(file = TALLOC_P(result, struct db_locked_file))) { + DEBUG(0, ("talloc failed\n")); + TALLOC_FREE(result); + return NULL; + } + + result->private_data = file; + result->store = db_file_store; + result->delete_rec = db_file_delete; + + result->key.dsize = key.dsize; + result->key.dptr = (uint8 *)talloc_memdup(result, key.dptr, key.dsize); + if (result->key.dptr == NULL) { + DEBUG(0, ("talloc failed\n")); + TALLOC_FREE(result); + return NULL; + } + + /* Cut to 8 bits */ + file->hash = fsh(key.dptr, key.dsize); + file->name = hex_encode(file, (unsigned char *)key.dptr, key.dsize); + if (file->name == NULL) { + DEBUG(0, ("hex_encode failed\n")); + TALLOC_FREE(result); + return NULL; + } + + file->path = talloc_asprintf(file, "%s/%2.2X/%s", ctx->dirname, + file->hash, file->name); + if (file->path == NULL) { + DEBUG(0, ("talloc_asprintf failed\n")); + TALLOC_FREE(result); + return NULL; + } + + become_root(); + file->fd = open(file->path, O_RDWR|O_CREAT, 0644); + unbecome_root(); + + if (file->fd < 0) { + DEBUG(3, ("Could not open/create %s: %s\n", + file->path, strerror(errno))); + TALLOC_FREE(result); + return NULL; + } + + talloc_set_destructor(file, db_locked_file_destr); + + fl.l_type = F_WRLCK; + fl.l_whence = SEEK_SET; + fl.l_start = 0; + fl.l_len = 1; + fl.l_pid = 0; + + do { + ret = fcntl(file->fd, F_SETLKW, &fl); + } while ((ret == -1) && (errno == EINTR)); + + if (ret == -1) { + DEBUG(3, ("Could not get lock on %s: %s\n", + file->path, strerror(errno))); + TALLOC_FREE(result); + return NULL; + } + + if (sys_fstat(file->fd, &statbuf) != 0) { + DEBUG(3, ("Could not fstat %s: %s\n", + file->path, strerror(errno))); + TALLOC_FREE(result); + return NULL; + } + + if (statbuf.st_nlink == 0) { + /* Someone has deleted it under the lock, retry */ + TALLOC_FREE(result); + goto again; + } + + result->value.dsize = 0; + result->value.dptr = NULL; + + if (statbuf.st_size != 0) { + result->value.dsize = statbuf.st_size; + result->value.dptr = TALLOC_ARRAY(result, uint8, + statbuf.st_size); + if (result->value.dptr == NULL) { + DEBUG(1, ("talloc failed\n")); + TALLOC_FREE(result); + return NULL; + } + + nread = read_data(file->fd, (char *)result->value.dptr, + result->value.dsize); + if (nread != result->value.dsize) { + DEBUG(3, ("read_data failed: %s\n", strerror(errno))); + TALLOC_FREE(result); + return NULL; + } + } + + ctx->locked_record = result; + file->parent = (struct db_file_ctx *)talloc_reference(file, ctx); + + return result; +} + +static NTSTATUS db_file_store_root(int fd, TDB_DATA data) +{ + if (sys_lseek(fd, 0, SEEK_SET) != 0) { + DEBUG(0, ("sys_lseek failed: %s\n", strerror(errno))); + return map_nt_error_from_unix(errno); + } + + if (write_data(fd, (char *)data.dptr, data.dsize) != data.dsize) { + DEBUG(3, ("write_data failed: %s\n", strerror(errno))); + return map_nt_error_from_unix(errno); + } + + if (sys_ftruncate(fd, data.dsize) != 0) { + DEBUG(3, ("sys_ftruncate failed: %s\n", strerror(errno))); + return map_nt_error_from_unix(errno); + } + + return NT_STATUS_OK; +} + +static NTSTATUS db_file_store(struct db_record *rec, TDB_DATA data, int flag) +{ + struct db_locked_file *file = + talloc_get_type_abort(rec->private_data, + struct db_locked_file); + NTSTATUS status; + + become_root(); + status = db_file_store_root(file->fd, data); + unbecome_root(); + + return status; +} + +static NTSTATUS db_file_delete(struct db_record *rec) +{ + struct db_locked_file *file = + talloc_get_type_abort(rec->private_data, + struct db_locked_file); + int res; + + become_root(); + res = unlink(file->path); + unbecome_root(); + + if (res == -1) { + DEBUG(3, ("unlink(%s) failed: %s\n", file->path, + strerror(errno))); + return map_nt_error_from_unix(errno); + } + + return NT_STATUS_OK; +} + +static int db_file_traverse(struct db_context *db, + int (*fn)(struct db_record *rec, + void *private_data), + void *private_data) +{ + struct db_file_ctx *ctx = talloc_get_type_abort(db->private_data, + struct db_file_ctx); + TALLOC_CTX *mem_ctx = talloc_init("traversal %s\n", ctx->dirname); + + int i; + int count = 0; + + for (i=0; i<256; i++) { + const char *dirname = talloc_asprintf(mem_ctx, "%s/%2.2X", + ctx->dirname, i); + DIR *dir; + struct dirent *dirent; + + if (dirname == NULL) { + DEBUG(0, ("talloc failed\n")); + TALLOC_FREE(mem_ctx); + return -1; + } + + dir = opendir(dirname); + if (dir == NULL) { + DEBUG(3, ("Could not open dir %s: %s\n", dirname, + strerror(errno))); + TALLOC_FREE(mem_ctx); + return -1; + } + + while ((dirent = readdir(dir)) != NULL) { + DATA_BLOB keyblob; + TDB_DATA key; + struct db_record *rec; + + if ((dirent->d_name[0] == '.') && + ((dirent->d_name[1] == '\0') || + ((dirent->d_name[1] == '.') && + (dirent->d_name[2] == '\0')))) { + continue; + } + + keyblob = strhex_to_data_blob(mem_ctx, dirent->d_name); + if (keyblob.data == NULL) { + DEBUG(5, ("strhex_to_data_blob failed\n")); + continue; + } + + key.dptr = keyblob.data; + key.dsize = keyblob.length; + + if ((ctx->locked_record != NULL) && + (key.dsize == ctx->locked_record->key.dsize) && + (memcmp(key.dptr, ctx->locked_record->key.dptr, + key.dsize) == 0)) { + count += 1; + if (fn(ctx->locked_record, + private_data) != 0) { + TALLOC_FREE(mem_ctx); + closedir(dir); + return count; + } + } + + rec = db_file_fetch_locked(db, mem_ctx, key); + if (rec == NULL) { + /* Someone might have deleted it */ + continue; + } + + if (rec->value.dptr == NULL) { + TALLOC_FREE(rec); + continue; + } + + count += 1; + + if (fn(rec, private_data) != 0) { + TALLOC_FREE(mem_ctx); + closedir(dir); + return count; + } + TALLOC_FREE(rec); + } + + closedir(dir); + } + + TALLOC_FREE(mem_ctx); + return count; +} + +struct db_context *db_open_file(TALLOC_CTX *mem_ctx, + struct messaging_context *msg_ctx, + const char *name, + int hash_size, int tdb_flags, + int open_flags, mode_t mode) +{ + struct db_context *result = NULL; + struct db_file_ctx *ctx; + + if (!(result = TALLOC_ZERO_P(mem_ctx, struct db_context))) { + DEBUG(0, ("talloc failed\n")); + return NULL; + } + + if (!(ctx = TALLOC_P(result, struct db_file_ctx))) { + DEBUG(0, ("talloc failed\n")); + TALLOC_FREE(result); + return NULL; + } + + result->private_data = ctx; + result->fetch_locked = db_file_fetch_locked; + result->traverse = db_file_traverse; + + ctx->locked_record = NULL; + if (!(ctx->dirname = talloc_strdup(ctx, name))) { + DEBUG(0, ("talloc failed\n")); + TALLOC_FREE(result); + return NULL; + } + + if (open_flags & O_CREAT) { + int ret, i; + + mode |= (mode & S_IRUSR) ? S_IXUSR : 0; + mode |= (mode & S_IRGRP) ? S_IXGRP : 0; + mode |= (mode & S_IROTH) ? S_IXOTH : 0; + + ret = mkdir(name, mode); + if ((ret != 0) && (errno != EEXIST)) { + DEBUG(5, ("mkdir(%s,%o) failed: %s\n", name, mode, + strerror(errno))); + TALLOC_FREE(result); + return NULL; + } + + for (i=0; i<256; i++) { + char *path; + path = talloc_asprintf(result, "%s/%2.2X", name, i); + if (path == NULL) { + DEBUG(0, ("asprintf failed\n")); + TALLOC_FREE(result); + return NULL; + } + ret = mkdir(path, mode); + if ((ret != 0) && (errno != EEXIST)) { + DEBUG(5, ("mkdir(%s,%o) failed: %s\n", path, + mode, strerror(errno))); + TALLOC_FREE(result); + return NULL; + } + TALLOC_FREE(path); + } + } + + return result; +} diff --git a/source3/lib/dbwrap_tdb.c b/source3/lib/dbwrap_tdb.c new file mode 100644 index 0000000000..238ba51761 --- /dev/null +++ b/source3/lib/dbwrap_tdb.c @@ -0,0 +1,227 @@ +/* + Unix SMB/CIFS implementation. + Database interface wrapper around tdb + Copyright (C) Volker Lendecke 2005-2007 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ + +#include "includes.h" + +struct db_tdb_ctx { + TDB_CONTEXT *tdb; +}; + +static NTSTATUS db_tdb_store(struct db_record *rec, TDB_DATA data, int flag); +static NTSTATUS db_tdb_delete(struct db_record *rec); + +static int db_tdb_record_destr(struct db_record* data) +{ + struct db_tdb_ctx *ctx = + talloc_get_type_abort(data->private_data, struct db_tdb_ctx); + + DEBUG(10, ("Unlocking key %s\n", + hex_encode(data, (unsigned char *)data->key.dptr, + data->key.dsize))); + + if (tdb_chainunlock(ctx->tdb, data->key) != 0) { + DEBUG(0, ("tdb_chainunlock failed\n")); + return -1; + } + return 0; +} + +static struct db_record *db_tdb_fetch_locked(struct db_context *db, + TALLOC_CTX *mem_ctx, TDB_DATA key) +{ + struct db_tdb_ctx *ctx = talloc_get_type_abort(db->private_data, + struct db_tdb_ctx); + struct db_record *result; + TDB_DATA value; + + result = TALLOC_P(mem_ctx, struct db_record); + if (result == NULL) { + DEBUG(0, ("talloc failed\n")); + return NULL; + } + + result->key.dsize = key.dsize; + result->key.dptr = (uint8 *)talloc_memdup(result, key.dptr, key.dsize); + if (result->key.dptr == NULL) { + DEBUG(0, ("talloc failed\n")); + TALLOC_FREE(result); + return NULL; + } + + result->value.dptr = NULL; + result->value.dsize = 0; + result->private_data = talloc_reference(result, ctx); + result->store = db_tdb_store; + result->delete_rec = db_tdb_delete; + + { + char *keystr = hex_encode(NULL, (unsigned char *)key.dptr, + key.dsize); + DEBUG(10, ("Locking key %s\n", keystr)); + TALLOC_FREE(keystr); + } + + if (tdb_chainlock(ctx->tdb, key) != 0) { + DEBUG(3, ("tdb_chainlock failed\n")); + TALLOC_FREE(result); + return NULL; + } + + talloc_set_destructor(result, db_tdb_record_destr); + + value = tdb_fetch(ctx->tdb, key); + + if (value.dptr == NULL) { + return result; + } + + result->value.dsize = value.dsize; + result->value.dptr = (uint8 *)talloc_memdup(result, value.dptr, + value.dsize); + if (result->value.dptr == NULL) { + DEBUG(3, ("talloc failed\n")); + TALLOC_FREE(result); + return NULL; + } + + SAFE_FREE(value.dptr); + + DEBUG(10, ("Allocated locked data 0x%p\n", result)); + + return result; +} + +static NTSTATUS db_tdb_store(struct db_record *rec, TDB_DATA data, int flag) +{ + struct db_tdb_ctx *ctx = talloc_get_type_abort(rec->private_data, + struct db_tdb_ctx); + + /* + * This has a bug: We need to replace rec->value for correct + * operation, but right now brlock and locking don't use the value + * anymore after it was stored. + */ + + return (tdb_store(ctx->tdb, rec->key, data, flag) == 0) ? + NT_STATUS_OK : NT_STATUS_UNSUCCESSFUL; +} + +static NTSTATUS db_tdb_delete(struct db_record *rec) +{ + struct db_tdb_ctx *ctx = talloc_get_type_abort(rec->private_data, + struct db_tdb_ctx); + + return (tdb_delete(ctx->tdb, rec->key) == 0) ? + NT_STATUS_OK : NT_STATUS_UNSUCCESSFUL; +} + +struct db_tdb_traverse_ctx { + struct db_context *db; + int (*f)(struct db_record *rec, void *private_data); + void *private_data; +}; + +static int db_tdb_traverse_func(TDB_CONTEXT *tdb, TDB_DATA kbuf, TDB_DATA dbuf, + void *private_data) +{ + struct db_tdb_traverse_ctx *ctx = + (struct db_tdb_traverse_ctx *)private_data; + struct db_record rec; + + rec.key = kbuf; + rec.value = dbuf; + rec.store = db_tdb_store; + rec.delete_rec = db_tdb_delete; + rec.private_data = ctx->db->private_data; + + return ctx->f(&rec, ctx->private_data); +} + +static int db_tdb_traverse(struct db_context *db, + int (*f)(struct db_record *rec, void *private_data), + void *private_data) +{ + struct db_tdb_ctx *db_ctx = + talloc_get_type_abort(db->private_data, struct db_tdb_ctx); + struct db_tdb_traverse_ctx ctx; + + ctx.db = db; + ctx.f = f; + ctx.private_data = private_data; + return tdb_traverse(db_ctx->tdb, db_tdb_traverse_func, &ctx); +} + +static int db_tdb_get_seqnum(struct db_context *db) + +{ + struct db_tdb_ctx *db_ctx = + talloc_get_type_abort(db->private_data, struct db_tdb_ctx); + return tdb_get_seqnum(db_ctx->tdb); +} + +static int db_tdb_ctx_destr(struct db_tdb_ctx *ctx) +{ + if (tdb_close(ctx->tdb) != 0) { + DEBUG(0, ("Failed to close tdb: %s\n", strerror(errno))); + return -1; + } + + return 0; +} + +struct db_context *db_open_tdb(TALLOC_CTX *mem_ctx, + const char *name, + int hash_size, int tdb_flags, + int open_flags, mode_t mode) +{ + struct db_context *result = NULL; + struct db_tdb_ctx *db_tdb; + + result = TALLOC_ZERO_P(mem_ctx, struct db_context); + if (result == NULL) { + DEBUG(0, ("talloc failed\n")); + goto fail; + } + + result->private_data = db_tdb = TALLOC_P(result, struct db_tdb_ctx); + if (db_tdb == NULL) { + DEBUG(0, ("talloc failed\n")); + goto fail; + } + + db_tdb->tdb = tdb_open_log(name, hash_size, tdb_flags, + open_flags, mode); + if (db_tdb->tdb == NULL) { + DEBUG(3, ("Could not open tdb: %s\n", strerror(errno))); + goto fail; + } + + talloc_set_destructor(db_tdb, db_tdb_ctx_destr); + result->fetch_locked = db_tdb_fetch_locked; + result->traverse = db_tdb_traverse; + result->get_seqnum = db_tdb_get_seqnum; + return result; + + fail: + if (result != NULL) { + TALLOC_FREE(result); + } + return NULL; +} -- cgit