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
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
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.
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/* This module implements a tdb based byte range locking service,
used. This allows us to provide the same semantics as NT */
#include "includes.h"
-#include "messages.h"
-
-/*
- in this module a "DATA_BLOB *file_key" is a blob that uniquely identifies
- a file. For a local posix filesystem this will usually be a combination
- of the device and inode numbers of the file, but it can be anything
- that uniquely idetifies a file for locking purposes, as long
- as it is applied consistently.
-*/
-
-/*
- the lock context contains the elements that define whether one
- lock is the same as another lock
-*/
-struct lock_context {
- servid_t server;
- uint16_t smbpid;
- uint16_t tid;
-};
-
-/* The data in brlock records is an unsorted linear array of these
- records. It is unnecessary to store the count as tdb provides the
- size of the record */
-struct lock_struct {
- struct lock_context context;
- uint64_t start;
- uint64_t size;
- uint16_t fnum;
- enum brl_type lock_type;
- void *notify_ptr;
-};
-
-struct brl_context {
- struct tdb_wrap *w;
- servid_t server;
- uint16_t tid;
- struct messaging_context *messaging_ctx;
- struct lock_struct last_lock_failure;
-};
-
-
-/*
- Open up the brlock.tdb database. Close it down using
- talloc_free(). We need the messaging_ctx to allow for
- pending lock notifications.
-*/
-struct brl_context *brl_init(TALLOC_CTX *mem_ctx, servid_t server, uint16_t tid,
- struct messaging_context *messaging_ctx)
-{
- char *path;
- struct brl_context *brl;
-
- brl = talloc_p(mem_ctx, struct brl_context);
- if (brl == NULL) {
- return NULL;
- }
-
- path = smbd_tmp_path(brl, "brlock.tdb");
- brl->w = tdb_wrap_open(brl, path, 0,
- TDB_DEFAULT, O_RDWR|O_CREAT, 0600);
- talloc_free(path);
- if (brl->w == NULL) {
- talloc_free(brl);
- return NULL;
- }
-
- brl->server = server;
- brl->tid = tid;
- brl->messaging_ctx = messaging_ctx;
- ZERO_STRUCT(brl->last_lock_failure);
-
- return brl;
-}
+#include "system/filesys.h"
+#include <tdb.h>
+#include "messaging/messaging.h"
+#include "lib/messaging/irpc.h"
+#include "libcli/libcli.h"
+#include "cluster/cluster.h"
+#include "ntvfs/common/ntvfs_common.h"
+static const struct brlock_ops *ops;
/*
- see if two locking contexts are equal
+ set the brl backend ops
*/
-static BOOL brl_same_context(struct lock_context *ctx1, struct lock_context *ctx2)
+void brl_set_ops(const struct brlock_ops *new_ops)
{
- return (ctx1->server == ctx2->server &&
- ctx1->smbpid == ctx2->smbpid &&
- ctx1->tid == ctx2->tid);
+ ops = new_ops;
}
/*
- see if lck1 and lck2 overlap
-*/
-static BOOL brl_overlap(struct lock_struct *lck1,
- struct lock_struct *lck2)
-{
- /* this extra check is not redundent - it copes with locks
- that go beyond the end of 64 bit file space */
- if (lck1->size != 0 &&
- lck1->start == lck2->start &&
- lck1->size == lck2->size) {
- return True;
- }
-
- if (lck1->start >= (lck2->start+lck2->size) ||
- lck2->start >= (lck1->start+lck1->size)) {
- return False;
- }
- return True;
-}
-
-/*
- See if lock2 can be added when lock1 is in place.
-*/
-static BOOL brl_conflict(struct lock_struct *lck1,
- struct lock_struct *lck2)
-{
- /* pending locks don't conflict with anything */
- if (lck1->lock_type >= PENDING_READ_LOCK ||
- lck2->lock_type >= PENDING_READ_LOCK) {
- return False;
- }
-
- if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
- return False;
- }
-
- if (brl_same_context(&lck1->context, &lck2->context) &&
- lck2->lock_type == READ_LOCK && lck1->fnum == lck2->fnum) {
- return False;
- }
-
- return brl_overlap(lck1, lck2);
-}
-
-
-/*
- Check to see if this lock conflicts, but ignore our own locks on the
- same fnum only.
+ Open up the brlock database. Close it down using talloc_free(). We
+ need the messaging_ctx to allow for pending lock notifications.
*/
-static BOOL brl_conflict_other(struct lock_struct *lck1, struct lock_struct *lck2)
+struct brl_context *brl_init(TALLOC_CTX *mem_ctx, struct server_id server,
+ struct loadparm_context *lp_ctx,
+ struct messaging_context *messaging_ctx)
{
- /* pending locks don't conflict with anything */
- if (lck1->lock_type >= PENDING_READ_LOCK ||
- lck2->lock_type >= PENDING_READ_LOCK) {
- return False;
+ if (ops == NULL) {
+ brl_tdb_init_ops();
}
+ return ops->brl_init(mem_ctx, server, lp_ctx, messaging_ctx);
+}
- if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK)
- return False;
-
- /*
- * note that incoming write calls conflict with existing READ
- * locks even if the context is the same. JRA. See LOCKTEST7
- * in smbtorture.
- */
- if (brl_same_context(&lck1->context, &lck2->context) &&
- lck1->fnum == lck2->fnum &&
- (lck2->lock_type == READ_LOCK || lck1->lock_type == WRITE_LOCK)) {
- return False;
- }
-
- return brl_overlap(lck1, lck2);
-}
-
-
-/*
- amazingly enough, w2k3 "remembers" whether the last lock failure
- is the same as this one and changes its error code. I wonder if any
- app depends on this?
-*/
-static NTSTATUS brl_lock_failed(struct brl_context *brl, struct lock_struct *lock)
+struct brl_handle *brl_create_handle(TALLOC_CTX *mem_ctx, struct ntvfs_handle *ntvfs, DATA_BLOB *file_key)
{
- if (brl_same_context(&lock->context, &brl->last_lock_failure.context) &&
- lock->fnum == brl->last_lock_failure.fnum &&
- lock->start == brl->last_lock_failure.start &&
- lock->size == brl->last_lock_failure.size) {
- return NT_STATUS_FILE_LOCK_CONFLICT;
- }
- brl->last_lock_failure = *lock;
- if (lock->start >= 0xEF000000 &&
- (lock->start >> 63) == 0) {
- /* amazing the little things you learn with a test
- suite. Locks beyond this offset (as a 64 bit
- number!) always generate the conflict error code,
- unless the top bit is set */
- return NT_STATUS_FILE_LOCK_CONFLICT;
- }
- return NT_STATUS_LOCK_NOT_GRANTED;
+ return ops->brl_create_handle(mem_ctx, ntvfs, file_key);
}
/*
notification is sent, identified by the notify_ptr
*/
NTSTATUS brl_lock(struct brl_context *brl,
- DATA_BLOB *file_key,
- uint16_t smbpid,
- uint16_t fnum,
+ struct brl_handle *brlh,
+ uint32_t smbpid,
uint64_t start, uint64_t size,
enum brl_type lock_type,
void *notify_ptr)
{
- TDB_DATA kbuf, dbuf;
- int count, i;
- struct lock_struct lock, *locks;
- char *tp;
- NTSTATUS status;
-
- kbuf.dptr = file_key->data;
- kbuf.dsize = file_key->length;
-
- if (tdb_chainlock(brl->w->tdb, kbuf) != 0) {
- return NT_STATUS_INTERNAL_DB_CORRUPTION;
- }
-
- /* if this is a pending lock, then with the chainlock held we
- try to get the real lock. If we succeed then we don't need
- to make it pending. This prevents a possible race condition
- where the pending lock gets created after the lock that is
- preventing the real lock gets removed */
- if (lock_type >= PENDING_READ_LOCK) {
- enum brl_type rw = (lock_type==PENDING_READ_LOCK? READ_LOCK : WRITE_LOCK);
- status = brl_lock(brl, file_key, smbpid, fnum, start, size, rw, NULL);
- if (NT_STATUS_IS_OK(status)) {
- tdb_chainunlock(brl->w->tdb, kbuf);
- return NT_STATUS_OK;
- }
- }
-
- dbuf = tdb_fetch(brl->w->tdb, kbuf);
-
- lock.context.smbpid = smbpid;
- lock.context.server = brl->server;
- lock.context.tid = brl->tid;
- lock.start = start;
- lock.size = size;
- lock.fnum = fnum;
- lock.lock_type = lock_type;
- lock.notify_ptr = notify_ptr;
-
- if (dbuf.dptr) {
- /* there are existing locks - make sure they don't conflict */
- locks = (struct lock_struct *)dbuf.dptr;
- count = dbuf.dsize / sizeof(*locks);
- for (i=0; i<count; i++) {
- if (brl_conflict(&locks[i], &lock)) {
- status = brl_lock_failed(brl, &lock);
- goto fail;
- }
- }
- }
-
- /* no conflicts - add it to the list of locks */
- tp = Realloc(dbuf.dptr, dbuf.dsize + sizeof(*locks));
- if (!tp) {
- status = NT_STATUS_NO_MEMORY;
- goto fail;
- } else {
- dbuf.dptr = tp;
- }
- memcpy(dbuf.dptr + dbuf.dsize, &lock, sizeof(lock));
- dbuf.dsize += sizeof(lock);
-
- if (tdb_store(brl->w->tdb, kbuf, dbuf, TDB_REPLACE) != 0) {
- status = NT_STATUS_INTERNAL_DB_CORRUPTION;
- goto fail;
- }
-
- free(dbuf.dptr);
- tdb_chainunlock(brl->w->tdb, kbuf);
-
- /* the caller needs to know if the real lock was granted. If
- we have reached here then it must be a pending lock that
- was granted, so tell them the lock failed */
- if (lock_type >= PENDING_READ_LOCK) {
- return brl_lock_failed(brl, &lock);
- }
-
- return NT_STATUS_OK;
-
- fail:
-
- free(dbuf.dptr);
- tdb_chainunlock(brl->w->tdb, kbuf);
- return status;
-}
-
-
-/*
- we are removing a lock that might be holding up a pending lock. Scan for pending
- locks that cover this range and if we find any then notify the server that it should
- retry the lock
-*/
-static void brl_notify_unlock(struct brl_context *brl,
- struct lock_struct *locks, int count,
- struct lock_struct *removed_lock)
-{
- int i, last_notice;
-
- /* the last_notice logic is to prevent stampeding on a lock
- range. It prevents us sending hundreds of notifies on the
- same range of bytes. It doesn't prevent all possible
- stampedes, but it does prevent the most common problem */
- last_notice = -1;
-
- for (i=0;i<count;i++) {
- if (locks[i].lock_type >= PENDING_READ_LOCK &&
- brl_overlap(&locks[i], removed_lock)) {
- if (last_notice != -1 && brl_overlap(&locks[i], &locks[last_notice])) {
- continue;
- }
- if (locks[i].lock_type == PENDING_WRITE_LOCK) {
- last_notice = i;
- }
- messaging_send_ptr(brl->messaging_ctx, locks[i].context.server,
- MSG_BRL_RETRY, locks[i].notify_ptr);
- }
- }
+ return ops->brl_lock(brl, brlh, smbpid, start, size, lock_type, notify_ptr);
}
-/*
- send notifications for all pending locks - the file is being closed by this
- user
-*/
-static void brl_notify_all(struct brl_context *brl,
- struct lock_struct *locks, int count)
-{
- int i;
- for (i=0;i<count;i++) {
- if (locks->lock_type >= PENDING_READ_LOCK) {
- brl_notify_unlock(brl, locks, count, &locks[i]);
- }
- }
-}
-
-
-
/*
Unlock a range of bytes.
*/
NTSTATUS brl_unlock(struct brl_context *brl,
- DATA_BLOB *file_key,
- uint16_t smbpid,
- uint16_t fnum,
+ struct brl_handle *brlh,
+ uint32_t smbpid,
uint64_t start, uint64_t size)
{
- TDB_DATA kbuf, dbuf;
- int count, i;
- struct lock_struct *locks;
- struct lock_context context;
- NTSTATUS status;
-
- kbuf.dptr = file_key->data;
- kbuf.dsize = file_key->length;
-
- if (tdb_chainlock(brl->w->tdb, kbuf) != 0) {
- return NT_STATUS_INTERNAL_DB_CORRUPTION;
- }
-
- dbuf = tdb_fetch(brl->w->tdb, kbuf);
- if (!dbuf.dptr) {
- tdb_chainunlock(brl->w->tdb, kbuf);
- return NT_STATUS_RANGE_NOT_LOCKED;
- }
-
- context.smbpid = smbpid;
- context.server = brl->server;
- context.tid = brl->tid;
-
- /* there are existing locks - find a match */
- locks = (struct lock_struct *)dbuf.dptr;
- count = dbuf.dsize / sizeof(*locks);
-
- for (i=0; i<count; i++) {
- struct lock_struct *lock = &locks[i];
-
- if (brl_same_context(&lock->context, &context) &&
- lock->fnum == fnum &&
- lock->start == start &&
- lock->size == size &&
- lock->notify_ptr == NULL) {
- /* found it - delete it */
- if (count == 1) {
- if (tdb_delete(brl->w->tdb, kbuf) != 0) {
- status = NT_STATUS_INTERNAL_DB_CORRUPTION;
- goto fail;
- }
- } else {
- struct lock_struct removed_lock = *lock;
- if (i < count-1) {
- memmove(&locks[i], &locks[i+1],
- sizeof(*locks)*((count-1) - i));
- }
- count--;
-
- /* send notifications for any relevant pending locks */
- brl_notify_unlock(brl, locks, count, &removed_lock);
-
- dbuf.dsize = count * sizeof(*locks);
-
- if (tdb_store(brl->w->tdb, kbuf, dbuf, TDB_REPLACE) != 0) {
- status = NT_STATUS_INTERNAL_DB_CORRUPTION;
- goto fail;
- }
- }
-
- free(dbuf.dptr);
- tdb_chainunlock(brl->w->tdb, kbuf);
- return NT_STATUS_OK;
- }
- }
-
- /* we didn't find it */
- status = NT_STATUS_RANGE_NOT_LOCKED;
-
- fail:
- free(dbuf.dptr);
- tdb_chainunlock(brl->w->tdb, kbuf);
- return status;
+ return ops->brl_unlock(brl, brlh, smbpid, start, size);
}
-
/*
remove a pending lock. This is called when the caller has either
given up trying to establish a lock or when they have succeeded in
getting it. In either case they no longer need to be notified.
*/
NTSTATUS brl_remove_pending(struct brl_context *brl,
- DATA_BLOB *file_key,
+ struct brl_handle *brlh,
void *notify_ptr)
{
- TDB_DATA kbuf, dbuf;
- int count, i;
- struct lock_struct *locks;
- NTSTATUS status;
-
- kbuf.dptr = file_key->data;
- kbuf.dsize = file_key->length;
-
- if (tdb_chainlock(brl->w->tdb, kbuf) != 0) {
- return NT_STATUS_INTERNAL_DB_CORRUPTION;
- }
-
- dbuf = tdb_fetch(brl->w->tdb, kbuf);
- if (!dbuf.dptr) {
- tdb_chainunlock(brl->w->tdb, kbuf);
- return NT_STATUS_RANGE_NOT_LOCKED;
- }
-
- /* there are existing locks - find a match */
- locks = (struct lock_struct *)dbuf.dptr;
- count = dbuf.dsize / sizeof(*locks);
-
- for (i=0; i<count; i++) {
- struct lock_struct *lock = &locks[i];
-
- if (lock->notify_ptr == notify_ptr &&
- lock->context.server == brl->server) {
- /* found it - delete it */
- if (count == 1) {
- if (tdb_delete(brl->w->tdb, kbuf) != 0) {
- status = NT_STATUS_INTERNAL_DB_CORRUPTION;
- goto fail;
- }
- } else {
- if (i < count-1) {
- memmove(&locks[i], &locks[i+1],
- sizeof(*locks)*((count-1) - i));
- }
- count--;
- dbuf.dsize = count * sizeof(*locks);
- if (tdb_store(brl->w->tdb, kbuf, dbuf, TDB_REPLACE) != 0) {
- status = NT_STATUS_INTERNAL_DB_CORRUPTION;
- goto fail;
- }
- }
-
- free(dbuf.dptr);
- tdb_chainunlock(brl->w->tdb, kbuf);
- return NT_STATUS_OK;
- }
- }
-
- /* we didn't find it */
- status = NT_STATUS_RANGE_NOT_LOCKED;
-
- fail:
- free(dbuf.dptr);
- tdb_chainunlock(brl->w->tdb, kbuf);
- return status;
+ return ops->brl_remove_pending(brl, brlh, notify_ptr);
}
Test if we are allowed to perform IO on a region of an open file
*/
NTSTATUS brl_locktest(struct brl_context *brl,
- DATA_BLOB *file_key,
- uint16_t fnum,
- uint16 smbpid,
+ struct brl_handle *brlh,
+ uint32_t smbpid,
uint64_t start, uint64_t size,
enum brl_type lock_type)
{
- TDB_DATA kbuf, dbuf;
- int count, i;
- struct lock_struct lock, *locks;
-
- kbuf.dptr = file_key->data;
- kbuf.dsize = file_key->length;
-
- dbuf = tdb_fetch(brl->w->tdb, kbuf);
- if (dbuf.dptr == NULL) {
- return NT_STATUS_OK;
- }
-
- lock.context.smbpid = smbpid;
- lock.context.server = brl->server;
- lock.context.tid = brl->tid;
- lock.start = start;
- lock.size = size;
- lock.fnum = fnum;
- lock.lock_type = lock_type;
-
- /* there are existing locks - make sure they don't conflict */
- locks = (struct lock_struct *)dbuf.dptr;
- count = dbuf.dsize / sizeof(*locks);
-
- for (i=0; i<count; i++) {
- if (brl_conflict_other(&locks[i], &lock)) {
- free(dbuf.dptr);
- return NT_STATUS_FILE_LOCK_CONFLICT;
- }
- }
-
- free(dbuf.dptr);
- return NT_STATUS_OK;
+ return ops->brl_locktest(brl, brlh, smbpid, start, size, lock_type);
}
Remove any locks associated with a open file.
*/
NTSTATUS brl_close(struct brl_context *brl,
- DATA_BLOB *file_key, int fnum)
+ struct brl_handle *brlh)
{
- TDB_DATA kbuf, dbuf;
- int count, i, dcount=0;
- struct lock_struct *locks;
- NTSTATUS status;
-
- kbuf.dptr = file_key->data;
- kbuf.dsize = file_key->length;
-
- if (tdb_chainlock(brl->w->tdb, kbuf) != 0) {
- return NT_STATUS_INTERNAL_DB_CORRUPTION;
- }
-
- dbuf = tdb_fetch(brl->w->tdb, kbuf);
- if (!dbuf.dptr) {
- tdb_chainunlock(brl->w->tdb, kbuf);
- return NT_STATUS_OK;
- }
-
- /* there are existing locks - remove any for this fnum */
- locks = (struct lock_struct *)dbuf.dptr;
- count = dbuf.dsize / sizeof(*locks);
-
- for (i=0; i<count; i++) {
- struct lock_struct *lock = &locks[i];
-
- if (lock->context.tid == brl->tid &&
- lock->context.server == brl->server &&
- lock->fnum == fnum) {
- /* found it - delete it */
- if (count > 1 && i < count-1) {
- memmove(&locks[i], &locks[i+1],
- sizeof(*locks)*((count-1) - i));
- }
- count--;
- i--;
- dcount++;
- }
- }
-
- status = NT_STATUS_OK;
-
- if (count == 0) {
- if (tdb_delete(brl->w->tdb, kbuf) != 0) {
- status = NT_STATUS_INTERNAL_DB_CORRUPTION;
- }
- } else if (dcount != 0) {
- /* tell all pending lock holders for this file that
- they have a chance now. This is a bit indiscriminant,
- but works OK */
- brl_notify_all(brl, locks, count);
-
- dbuf.dsize = count * sizeof(*locks);
-
- if (tdb_store(brl->w->tdb, kbuf, dbuf, TDB_REPLACE) != 0) {
- status = NT_STATUS_INTERNAL_DB_CORRUPTION;
- }
- }
-
- free(dbuf.dptr);
- tdb_chainunlock(brl->w->tdb, kbuf);
-
- return status;
+ return ops->brl_close(brl, brlh);
}
+/*
+ Get a number of locks associated with a open file.
+*/
+NTSTATUS brl_count(struct brl_context *brl,
+ struct brl_handle *brlh,
+ int *count)
+{
+ return ops->brl_count(brl, brlh, count);
+}
git.samba.org / kai / samba.git / blobdiff