diff options
author | Andrew Tridgell <tridge@samba.org> | 2007-01-19 03:58:16 +0000 |
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committer | Gerald (Jerry) Carter <jerry@samba.org> | 2007-10-10 14:43:46 -0500 |
commit | be05a5ca2525f7f3ab732a5b5c7baceb7c7a4ada (patch) | |
tree | bae27286ae29f731ca59934b0f95289b1e83a315 /source4/ntvfs/common/brlock.c | |
parent | 20b406ce23a467b1424e3de9f82f54b9385a951d (diff) | |
download | samba-be05a5ca2525f7f3ab732a5b5c7baceb7c7a4ada.tar.gz samba-be05a5ca2525f7f3ab732a5b5c7baceb7c7a4ada.tar.bz2 samba-be05a5ca2525f7f3ab732a5b5c7baceb7c7a4ada.zip |
r20891: enable multiple brlock backends. The tdb backend is the default. The
prototype ctdb backend is in cluster/ctdb/brlock_ctdb.c
(This used to be commit 84d0e5316299931dc26f2a7b86962d2fffcc4b71)
Diffstat (limited to 'source4/ntvfs/common/brlock.c')
-rw-r--r-- | source4/ntvfs/common/brlock.c | 689 |
1 files changed, 0 insertions, 689 deletions
diff --git a/source4/ntvfs/common/brlock.c b/source4/ntvfs/common/brlock.c deleted file mode 100644 index c42c2f3a11..0000000000 --- a/source4/ntvfs/common/brlock.c +++ /dev/null @@ -1,689 +0,0 @@ -/* - Unix SMB/CIFS implementation. - - generic byte range locking code - - Copyright (C) Andrew Tridgell 1992-2004 - Copyright (C) Jeremy Allison 1992-2000 - - 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. -*/ - -/* This module implements a tdb based byte range locking service, - replacing the fcntl() based byte range locking previously - used. This allows us to provide the same semantics as NT */ - -#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 "libcli/libcli.h" -#include "cluster/cluster.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. -*/ - -struct brl_context; -/* - the lock context contains the elements that define whether one - lock is the same as another lock -*/ -struct lock_context { - struct server_id server; - uint16_t smbpid; - struct brl_context *ctx; -}; - -/* 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; - struct ntvfs_handle *ntvfs; - uint64_t start; - uint64_t size; - enum brl_type lock_type; - void *notify_ptr; -}; - -/* this struct is attached to on oprn file handle */ -struct brl_handle { - DATA_BLOB key; - struct ntvfs_handle *ntvfs; - struct lock_struct last_lock; -}; - -/* this struct is typicaly attached to tcon */ -struct brl_context { - struct tdb_wrap *w; - struct server_id server; - struct messaging_context *messaging_ctx; -}; - -/* - 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, struct server_id server, - struct messaging_context *messaging_ctx) -{ - char *path; - struct brl_context *brl; - - brl = talloc(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->messaging_ctx = messaging_ctx; - - return brl; -} - -struct brl_handle *brl_create_handle(TALLOC_CTX *mem_ctx, struct ntvfs_handle *ntvfs, DATA_BLOB *file_key) -{ - struct brl_handle *brlh; - - brlh = talloc(mem_ctx, struct brl_handle); - if (brlh == NULL) { - return NULL; - } - - brlh->key = *file_key; - brlh->ntvfs = ntvfs; - ZERO_STRUCT(brlh->last_lock); - - return brlh; -} - -/* - see if two locking contexts are equal -*/ -static BOOL brl_same_context(struct lock_context *ctx1, struct lock_context *ctx2) -{ - return (cluster_id_equal(&ctx1->server, &ctx2->server) && - ctx1->smbpid == ctx2->smbpid && - ctx1->ctx == ctx2->ctx); -} - -/* - 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->ntvfs == lck2->ntvfs) { - return False; - } - - return brl_overlap(lck1, lck2); -} - - -/* - Check to see if this lock conflicts, but ignore our own locks on the - same fnum only. -*/ -static BOOL brl_conflict_other(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; - - /* - * 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->ntvfs == lck2->ntvfs && - (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_handle *brlh, struct lock_struct *lock) -{ - /* - * this function is only called for non pending lock! - */ - - /* - * if the notify_ptr is non NULL, - * it means that we're at the end of a pending lock - * and the real lock is requested after the timout went by - * In this case we need to remember the last_lock and always - * give FILE_LOCK_CONFLICT - */ - if (lock->notify_ptr) { - brlh->last_lock = *lock; - return NT_STATUS_FILE_LOCK_CONFLICT; - } - - /* - * 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 - */ - if (lock->start >= 0xEF000000 && (lock->start >> 63) == 0) { - brlh->last_lock = *lock; - return NT_STATUS_FILE_LOCK_CONFLICT; - } - - /* - * if the current lock matches the last failed lock on the file handle - * and starts at the same offset, then FILE_LOCK_CONFLICT should be returned - */ - if (cluster_id_equal(&lock->context.server, &brlh->last_lock.context.server) && - lock->context.ctx == brlh->last_lock.context.ctx && - lock->ntvfs == brlh->last_lock.ntvfs && - lock->start == brlh->last_lock.start) { - return NT_STATUS_FILE_LOCK_CONFLICT; - } - - brlh->last_lock = *lock; - return NT_STATUS_LOCK_NOT_GRANTED; -} - -/* - Lock a range of bytes. The lock_type can be a PENDING_*_LOCK, in - which case a real lock is first tried, and if that fails then a - pending lock is created. When the pending lock is triggered (by - someone else closing an overlapping lock range) a messaging - notification is sent, identified by the notify_ptr -*/ -NTSTATUS brl_lock(struct brl_context *brl, - struct brl_handle *brlh, - uint16_t smbpid, - uint64_t start, uint64_t size, - enum brl_type lock_type, - void *notify_ptr) -{ - TDB_DATA kbuf, dbuf; - int count=0, i; - struct lock_struct lock, *locks=NULL; - NTSTATUS status; - - kbuf.dptr = brlh->key.data; - kbuf.dsize = brlh->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); - - /* here we need to force that the last_lock isn't overwritten */ - lock = brlh->last_lock; - status = brl_lock(brl, brlh, smbpid, start, size, rw, NULL); - brlh->last_lock = lock; - - 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.ctx = brl; - lock.ntvfs = brlh->ntvfs; - lock.context.ctx = brl; - lock.start = start; - lock.size = size; - 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(brlh, &lock); - goto fail; - } - } - } - - /* no conflicts - add it to the list of locks */ - locks = realloc_p(locks, struct lock_struct, count+1); - if (!locks) { - status = NT_STATUS_NO_MEMORY; - goto fail; - } else { - dbuf.dptr = (uint8_t *)locks; - } - locks[count] = 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 NT_STATUS_LOCK_NOT_GRANTED; - } - - 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); - } - } -} - - -/* - 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, - struct brl_handle *brlh, - uint16_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 = brlh->key.data; - kbuf.dsize = brlh->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.ctx = brl; - - /* 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->ntvfs == brlh->ntvfs && - lock->start == start && - lock->size == size && - lock->lock_type < PENDING_READ_LOCK) { - /* 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; -} - - -/* - 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, - struct brl_handle *brlh, - void *notify_ptr) -{ - TDB_DATA kbuf, dbuf; - int count, i; - struct lock_struct *locks; - NTSTATUS status; - - kbuf.dptr = brlh->key.data; - kbuf.dsize = brlh->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->lock_type >= PENDING_READ_LOCK && - lock->notify_ptr == notify_ptr && - cluster_id_equal(&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; -} - - -/* - Test if we are allowed to perform IO on a region of an open file -*/ -NTSTATUS brl_locktest(struct brl_context *brl, - struct brl_handle *brlh, - uint16_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 = brlh->key.data; - kbuf.dsize = brlh->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.ctx = brl; - lock.ntvfs = brlh->ntvfs; - lock.start = start; - lock.size = size; - 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; -} - - -/* - Remove any locks associated with a open file. -*/ -NTSTATUS brl_close(struct brl_context *brl, - struct brl_handle *brlh) -{ - TDB_DATA kbuf, dbuf; - int count, i, dcount=0; - struct lock_struct *locks; - NTSTATUS status; - - kbuf.dptr = brlh->key.data; - kbuf.dsize = brlh->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.ctx == brl && - cluster_id_equal(&lock->context.server, &brl->server) && - lock->ntvfs == brlh->ntvfs) { - /* 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; -} - |