r21807: modularise the opendb code, so different backends can be

implemented. This will allow for a ctdb opendb backend.
(This used to be commit 6b91ca0968209ad17489341c78d9610607cc8320)

1 files changed, 20 insertions, 458 deletions

diff --git a/source4/ntvfs/common/opendb.c b/source4/ntvfs/common/opendb.c
index 875f90760c..c17b819c04 100644
--- a/source4/ntvfs/common/opendb.c
+++ b/source4/ntvfs/common/opendb.c
@@ -39,30 +39,19 @@
 */
 
 #include "includes.h"
-#include "system/filesys.h"
-#include "lib/tdb/include/tdb.h"
-#include "messaging/messaging.h"
-#include "db_wrap.h"
-#include "lib/messaging/irpc.h"
-#include "librpc/gen_ndr/ndr_opendb.h"
 #include "ntvfs/ntvfs.h"
 #include "ntvfs/common/ntvfs_common.h"
 #include "cluster/cluster.h"
 
-struct odb_context {
-	struct tdb_wrap *w;
-	struct ntvfs_context *ntvfs_ctx;
-	BOOL oplocks;
-};
+static const struct opendb_ops *ops;
 
 /*
-  an odb lock handle. You must obtain one of these using odb_lock() before doing
-  any other operations. 
+  set the odb backend ops
 */
-struct odb_lock {
-	struct odb_context *odb;
-	TDB_DATA key;
-};
+void odb_set_ops(const struct opendb_ops *new_ops)
+{
+	ops = new_ops;
+}
 
 /*
   Open up the openfiles.tdb database. Close it down using
@@ -72,34 +61,10 @@ struct odb_lock {
 _PUBLIC_ struct odb_context *odb_init(TALLOC_CTX *mem_ctx, 
 				      struct ntvfs_context *ntvfs_ctx)
 {
-	struct odb_context *odb;
-
-	odb = talloc(mem_ctx, struct odb_context);
-	if (odb == NULL) {
-		return NULL;
-	}
-
-	odb->w = cluster_tdb_tmp_open(odb, "openfiles.tdb", TDB_DEFAULT);
-	if (odb->w == NULL) {
-		talloc_free(odb);
-		return NULL;
+	if (ops == NULL) {
+		odb_tdb_init_ops();
 	}
-
-	odb->ntvfs_ctx = ntvfs_ctx;
-
-	/* leave oplocks disabled by default until the code is working */
-	odb->oplocks = lp_parm_bool(-1, "opendb", "oplocks", False);
-
-	return odb;
-}
-
-/*
-  destroy a lock on the database
-*/
-static int odb_lock_destructor(struct odb_lock *lck)
-{
-	tdb_chainunlock(lck->odb->w->tdb, lck->key);
-	return 0;
+	return ops->odb_init(mem_ctx, ntvfs_ctx);
 }
 
 /*
@@ -109,153 +74,9 @@ static int odb_lock_destructor(struct odb_lock *lck)
 _PUBLIC_ struct odb_lock *odb_lock(TALLOC_CTX *mem_ctx,
 				   struct odb_context *odb, DATA_BLOB *file_key)
 {
-	struct odb_lock *lck;
-
-	lck = talloc(mem_ctx, struct odb_lock);
-	if (lck == NULL) {
-		return NULL;
-	}
-
-	lck->odb = talloc_reference(lck, odb);
-	lck->key.dptr = talloc_memdup(lck, file_key->data, file_key->length);
-	lck->key.dsize = file_key->length;
-	if (lck->key.dptr == NULL) {
-		talloc_free(lck);
-		return NULL;
-	}
-
-	if (tdb_chainlock(odb->w->tdb, lck->key) != 0) {
-		talloc_free(lck);
-		return NULL;
-	}
-
-	talloc_set_destructor(lck, odb_lock_destructor);
-	
-	return lck;
+	return ops->odb_lock(mem_ctx, odb, file_key);
 }
 
-/*
-  determine if two odb_entry structures conflict
-
-  return NT_STATUS_OK on no conflict
-*/
-static NTSTATUS share_conflict(struct opendb_entry *e1, struct opendb_entry *e2)
-{
-	/* if either open involves no read.write or delete access then
-	   it can't conflict */
-	if (!(e1->access_mask & (SEC_FILE_WRITE_DATA |
-				 SEC_FILE_APPEND_DATA |
-				 SEC_FILE_READ_DATA |
-				 SEC_FILE_EXECUTE |
-				 SEC_STD_DELETE))) {
-		return NT_STATUS_OK;
-	}
-	if (!(e2->access_mask & (SEC_FILE_WRITE_DATA |
-				 SEC_FILE_APPEND_DATA |
-				 SEC_FILE_READ_DATA |
-				 SEC_FILE_EXECUTE |
-				 SEC_STD_DELETE))) {
-		return NT_STATUS_OK;
-	}
-
-	/* data IO access masks. This is skipped if the two open handles
-	   are on different streams (as in that case the masks don't
-	   interact) */
-	if (e1->stream_id != e2->stream_id) {
-		return NT_STATUS_OK;
-	}
-
-#define CHECK_MASK(am, right, sa, share) \
-	if (((am) & (right)) && !((sa) & (share))) return NT_STATUS_SHARING_VIOLATION
-
-	CHECK_MASK(e1->access_mask, SEC_FILE_WRITE_DATA | SEC_FILE_APPEND_DATA,
-		   e2->share_access, NTCREATEX_SHARE_ACCESS_WRITE);
-	CHECK_MASK(e2->access_mask, SEC_FILE_WRITE_DATA | SEC_FILE_APPEND_DATA,
-		   e1->share_access, NTCREATEX_SHARE_ACCESS_WRITE);
-	
-	CHECK_MASK(e1->access_mask, SEC_FILE_READ_DATA | SEC_FILE_EXECUTE,
-		   e2->share_access, NTCREATEX_SHARE_ACCESS_READ);
-	CHECK_MASK(e2->access_mask, SEC_FILE_READ_DATA | SEC_FILE_EXECUTE,
-		   e1->share_access, NTCREATEX_SHARE_ACCESS_READ);
-
-	CHECK_MASK(e1->access_mask, SEC_STD_DELETE,
-		   e2->share_access, NTCREATEX_SHARE_ACCESS_DELETE);
-	CHECK_MASK(e2->access_mask, SEC_STD_DELETE,
-		   e1->share_access, NTCREATEX_SHARE_ACCESS_DELETE);
-
-	return NT_STATUS_OK;
-}
-
-/*
-  pull a record, translating from the db format to the opendb_file structure defined
-  in opendb.idl
-*/
-static NTSTATUS odb_pull_record(struct odb_lock *lck, struct opendb_file *file)
-{
-	struct odb_context *odb = lck->odb;
-	TDB_DATA dbuf;
-	DATA_BLOB blob;
-	NTSTATUS status;
-		
-	dbuf = tdb_fetch(odb->w->tdb, lck->key);
-	if (dbuf.dptr == NULL) {
-		return NT_STATUS_OBJECT_NAME_NOT_FOUND;
-	}
-
-	blob.data = dbuf.dptr;
-	blob.length = dbuf.dsize;
-
-	status = ndr_pull_struct_blob(&blob, lck, file, (ndr_pull_flags_fn_t)ndr_pull_opendb_file);
-
-	free(dbuf.dptr);
-
-	return status;
-}
-
-/*
-  push a record, translating from the opendb_file structure defined in opendb.idl
-*/
-static NTSTATUS odb_push_record(struct odb_lock *lck, struct opendb_file *file)
-{
-	struct odb_context *odb = lck->odb;
-	TDB_DATA dbuf;
-	DATA_BLOB blob;
-	NTSTATUS status;
-	int ret;
-
-	if (file->num_entries == 0) {
-		ret = tdb_delete(odb->w->tdb, lck->key);
-		if (ret != 0) {
-			return NT_STATUS_INTERNAL_DB_CORRUPTION;
-		}
-		return NT_STATUS_OK;
-	}
-
-	status = ndr_push_struct_blob(&blob, lck, file, (ndr_push_flags_fn_t)ndr_push_opendb_file);
-	NT_STATUS_NOT_OK_RETURN(status);
-
-	dbuf.dptr = blob.data;
-	dbuf.dsize = blob.length;
-		
-	ret = tdb_store(odb->w->tdb, lck->key, dbuf, TDB_REPLACE);
-	data_blob_free(&blob);
-	if (ret != 0) {
-		return NT_STATUS_INTERNAL_DB_CORRUPTION;
-	}
-
-	return NT_STATUS_OK;
-}
-
-/*
-  send an oplock break to a client
-*/
-static NTSTATUS odb_oplock_break_send(struct odb_context *odb, struct opendb_entry *e)
-{
-	/* tell the server handling this open file about the need to send the client
-	   a break */
-	return messaging_send_ptr(odb->ntvfs_ctx->msg_ctx, e->server, 
-				  MSG_NTVFS_OPLOCK_BREAK, e->file_handle);
-}
 
 /*
   register an open file in the open files database. This implements the share_access
@@ -270,97 +91,9 @@ _PUBLIC_ NTSTATUS odb_open_file(struct odb_lock *lck, void *file_handle,
 				const char *path, 
 				uint32_t oplock_level, uint32_t *oplock_granted)
 {
-	struct odb_context *odb = lck->odb;
-	struct opendb_entry e;
-	int i;
-	struct opendb_file file;
-	NTSTATUS status;
-
-	if (odb->oplocks == False) {
-		oplock_level = OPLOCK_NONE;
-	}
-
-	status = odb_pull_record(lck, &file);
-	if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
-		/* initialise a blank structure */
-		ZERO_STRUCT(file);
-		file.path = path;
-	} else {
-		NT_STATUS_NOT_OK_RETURN(status);
-	}
-
-	/* see if it conflicts */
-	e.server          = odb->ntvfs_ctx->server_id;
-	e.file_handle     = file_handle;
-	e.stream_id       = stream_id;
-	e.share_access    = share_access;
-	e.access_mask     = access_mask;
-	e.delete_on_close = delete_on_close;
-	e.oplock_level    = OPLOCK_NONE;
-		
-	/* see if anyone has an oplock, which we need to break */
-	for (i=0;i<file.num_entries;i++) {
-		if (file.entries[i].oplock_level == OPLOCK_BATCH) {
-			/* a batch oplock caches close calls, which
-			   means the client application might have
-			   already closed the file. We have to allow
-			   this close to propogate by sending a oplock
-			   break request and suspending this call
-			   until the break is acknowledged or the file
-			   is closed */
-			odb_oplock_break_send(odb, &file.entries[i]);
-			return NT_STATUS_OPLOCK_NOT_GRANTED;
-		}
-	}
-
-	if (file.delete_on_close || 
-	    (file.num_entries != 0 && delete_on_close)) {
-		/* while delete on close is set, no new opens are allowed */
-		return NT_STATUS_DELETE_PENDING;
-	}
-
-	/* check for sharing violations */
-	for (i=0;i<file.num_entries;i++) {
-		status = share_conflict(&file.entries[i], &e);
-		NT_STATUS_NOT_OK_RETURN(status);
-	}
-
-	/* we now know the open could succeed, but we need to check
-	   for any exclusive oplocks. We can't grant a second open
-	   till these are broken. Note that we check for batch oplocks
-	   before checking for sharing violations, and check for
-	   exclusive oplocks afterwards. */
-	for (i=0;i<file.num_entries;i++) {
-		if (file.entries[i].oplock_level == OPLOCK_EXCLUSIVE) {
-			odb_oplock_break_send(odb, &file.entries[i]);
-			return NT_STATUS_OPLOCK_NOT_GRANTED;
-		}
-	}
-
-	/*
-	  possibly grant an exclusive or batch oplock if this is the only client
-	  with the file open. We don't yet grant levelII oplocks.
-	*/
-	if (oplock_granted != NULL) {
-		if ((oplock_level == OPLOCK_BATCH ||
-		     oplock_level == OPLOCK_EXCLUSIVE) &&
-		    file.num_entries == 0) {
-			(*oplock_granted) = oplock_level;
-		} else {
-			(*oplock_granted) = OPLOCK_NONE;
-		}
-		e.oplock_level = (*oplock_granted);
-	}
-
-	/* it doesn't conflict, so add it to the end */
-	file.entries = talloc_realloc(lck, file.entries, struct opendb_entry, 
-				      file.num_entries+1);
-	NT_STATUS_HAVE_NO_MEMORY(file.entries);
-
-	file.entries[file.num_entries] = e;
-	file.num_entries++;
-
-	return odb_push_record(lck, &file);
+	return ops->odb_open_file(lck, file_handle, stream_id, share_access,
+				  access_mask, delete_on_close, path, oplock_level,
+				  oplock_granted);
 }
 
 
@@ -369,23 +102,7 @@ _PUBLIC_ NTSTATUS odb_open_file(struct odb_lock *lck, void *file_handle,
 */
 _PUBLIC_ NTSTATUS odb_open_file_pending(struct odb_lock *lck, void *private)
 {
-	struct odb_context *odb = lck->odb;
-	struct opendb_file file;
-	NTSTATUS status;
-		
-	status = odb_pull_record(lck, &file);
-	NT_STATUS_NOT_OK_RETURN(status);
-
-	file.pending = talloc_realloc(lck, file.pending, struct opendb_pending, 
-				      file.num_pending+1);
-	NT_STATUS_HAVE_NO_MEMORY(file.pending);
-
-	file.pending[file.num_pending].server = odb->ntvfs_ctx->server_id;
-	file.pending[file.num_pending].notify_ptr = private;
-
-	file.num_pending++;
-
-	return odb_push_record(lck, &file);
+	return ops->odb_open_file_pending(lck, private);
 }
 
 
@@ -394,45 +111,7 @@ _PUBLIC_ NTSTATUS odb_open_file_pending(struct odb_lock *lck, void *private)
 */
 _PUBLIC_ NTSTATUS odb_close_file(struct odb_lock *lck, void *file_handle)
 {
-	struct odb_context *odb = lck->odb;
-	struct opendb_file file;
-	int i;
-	NTSTATUS status;
-
-	status = odb_pull_record(lck, &file);
-	NT_STATUS_NOT_OK_RETURN(status);
-
-	/* find the entry, and delete it */
-	for (i=0;i<file.num_entries;i++) {
-		if (file_handle == file.entries[i].file_handle &&
-		    cluster_id_equal(&odb->ntvfs_ctx->server_id, &file.entries[i].server)) {
-			if (file.entries[i].delete_on_close) {
-				file.delete_on_close = True;
-			}
-			if (i < file.num_entries-1) {
-				memmove(file.entries+i, file.entries+i+1, 
-					(file.num_entries - (i+1)) * 
-					sizeof(struct opendb_entry));
-			}
-			break;
-		}
-	}
-
-	if (i == file.num_entries) {
-		return NT_STATUS_UNSUCCESSFUL;
-	}
-
-	/* send any pending notifications, removing them once sent */
-	for (i=0;i<file.num_pending;i++) {
-		messaging_send_ptr(odb->ntvfs_ctx->msg_ctx, file.pending[i].server, 
-				   MSG_PVFS_RETRY_OPEN, 
-				   file.pending[i].notify_ptr);
-	}
-	file.num_pending = 0;
-
-	file.num_entries--;
-	
-	return odb_push_record(lck, &file);
+	return ops->odb_close_file(lck, file_handle);
 }
 
 
@@ -441,34 +120,7 @@ _PUBLIC_ NTSTATUS odb_close_file(struct odb_lock *lck, void *file_handle)
 */
 _PUBLIC_ NTSTATUS odb_remove_pending(struct odb_lock *lck, void *private)
 {
-	struct odb_context *odb = lck->odb;
-	int i;
-	NTSTATUS status;
-	struct opendb_file file;
-
-	status = odb_pull_record(lck, &file);
-	NT_STATUS_NOT_OK_RETURN(status);
-
-	/* find the entry, and delete it */
-	for (i=0;i<file.num_pending;i++) {
-		if (private == file.pending[i].notify_ptr &&
-		    cluster_id_equal(&odb->ntvfs_ctx->server_id, &file.pending[i].server)) {
-			if (i < file.num_pending-1) {
-				memmove(file.pending+i, file.pending+i+1, 
-					(file.num_pending - (i+1)) * 
-					sizeof(struct opendb_pending));
-			}
-			break;
-		}
-	}
-
-	if (i == file.num_pending) {
-		return NT_STATUS_UNSUCCESSFUL;
-	}
-
-	file.num_pending--;
-	
-	return odb_push_record(lck, &file);
+	return ops->odb_remove_pending(lck, private);
 }
 
 
@@ -477,18 +129,7 @@ _PUBLIC_ NTSTATUS odb_remove_pending(struct odb_lock *lck, void *private)
 */
 _PUBLIC_ NTSTATUS odb_rename(struct odb_lock *lck, const char *path)
 {
-	struct opendb_file file;
-	NTSTATUS status;
-
-	status = odb_pull_record(lck, &file);
-	if (NT_STATUS_EQUAL(NT_STATUS_OBJECT_NAME_NOT_FOUND, status)) {
-		/* not having the record at all is OK */
-		return NT_STATUS_OK;
-	}
-	NT_STATUS_NOT_OK_RETURN(status);
-
-	file.path = path;
-	return odb_push_record(lck, &file);
+	return ops->odb_rename(lck, path);
 }
 
 /*
@@ -496,15 +137,7 @@ _PUBLIC_ NTSTATUS odb_rename(struct odb_lock *lck, const char *path)
 */
 _PUBLIC_ NTSTATUS odb_set_delete_on_close(struct odb_lock *lck, BOOL del_on_close)
 {
-	NTSTATUS status;
-	struct opendb_file file;
-
-	status = odb_pull_record(lck, &file);
-	NT_STATUS_NOT_OK_RETURN(status);
-
-	file.delete_on_close = del_on_close;
-
-	return odb_push_record(lck, &file);
+	return ops->odb_set_delete_on_close(lck, del_on_close);
 }
 
 /*
@@ -515,39 +148,7 @@ _PUBLIC_ NTSTATUS odb_get_delete_on_close(struct odb_context *odb,
 					  DATA_BLOB *key, BOOL *del_on_close, 
 					  int *open_count, char **path)
 {
-	NTSTATUS status;
-	struct opendb_file file;
-	struct odb_lock *lck;
-
-	lck = odb_lock(odb, odb, key);
-	NT_STATUS_HAVE_NO_MEMORY(lck);
-
-	status = odb_pull_record(lck, &file);
-	if (NT_STATUS_EQUAL(NT_STATUS_OBJECT_NAME_NOT_FOUND, status)) {
-		talloc_free(lck);
-		(*del_on_close) = False;
-		return NT_STATUS_OK;
-	}
-	if (!NT_STATUS_IS_OK(status)) {
-		talloc_free(lck);
-		return status;
-	}
-
-	(*del_on_close) = file.delete_on_close;
-	if (open_count != NULL) {
-		(*open_count) = file.num_entries;
-	}
-	if (path != NULL) {
-		*path = talloc_strdup(odb, file.path);
-		NT_STATUS_HAVE_NO_MEMORY(*path);
-		if (file.num_entries == 1 && file.entries[0].delete_on_close) {
-			(*del_on_close) = True;
-		}
-	}
-
-	talloc_free(lck);
-
-	return NT_STATUS_OK;
+	return ops->odb_get_delete_on_close(odb, key, del_on_close, open_count, path);
 }
 
 
@@ -559,44 +160,5 @@ _PUBLIC_ NTSTATUS odb_can_open(struct odb_lock *lck,
 			       uint32_t share_access, uint32_t create_options, 
 			       uint32_t access_mask)
 {
-	struct odb_context *odb = lck->odb;
-	NTSTATUS status;
-	struct opendb_file file;
-	struct opendb_entry e;
-	int i;
-
-	status = odb_pull_record(lck, &file);
-	if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
-		return NT_STATUS_OK;
-	}
-	NT_STATUS_NOT_OK_RETURN(status);
-
-	if ((create_options & NTCREATEX_OPTIONS_DELETE_ON_CLOSE) && 
-	    file.num_entries != 0) {
-		return NT_STATUS_SHARING_VIOLATION;
-	}
-
-	if (file.delete_on_close) {
-		return NT_STATUS_DELETE_PENDING;
-	}
-
-	e.server       = odb->ntvfs_ctx->server_id;
-	e.file_handle  = NULL;
-	e.stream_id    = 0;
-	e.share_access = share_access;
-	e.access_mask  = access_mask;
-		
-	for (i=0;i<file.num_entries;i++) {
-		status = share_conflict(&file.entries[i], &e);
-		if (!NT_STATUS_IS_OK(status)) {
-			/* note that we discard the error code
-			   here. We do this as unless we are actually
-			   doing an open (which comes via a different
-			   function), we need to return a sharing
-			   violation */
-			return NT_STATUS_SHARING_VIOLATION;
-		}
-	}
-
-	return NT_STATUS_OK;
+	return ops->odb_can_open(lck, share_access, create_options, access_mask);
 }