}
/****************************************************************************
- Add an entry into the POSIX locking tdb. Returns the number of records that
- completely overlap this request, or -1 on error. entry_num gets set to the
- index number of the added lock (used in case we need to delete *exactly*
- this entry).
+ Add an entry into the POSIX locking tdb. We return the index number of the
+ added lock (used in case we need to delete *exactly* this entry). Returns
+ False on fail, True on success.
****************************************************************************/
-static int add_posix_lock_entry(files_struct *fsp, SMB_OFF_T start, SMB_OFF_T size, int lock_type, size_t *entry_num)
+static BOOL add_posix_lock_entry(files_struct *fsp, SMB_OFF_T start, SMB_OFF_T size, int lock_type, size_t *pentry_num)
{
TDB_DATA kbuf = locking_key_fsp(fsp);
TDB_DATA dbuf;
struct posix_lock pl;
- struct posix_lock *entries;
- size_t i, count;
- int num_overlapping_records = 0;
- *entry_num = 0;
-
- /*
- * Windows is very strange. It allows read locks to be overlayed on
- * a write lock, but leaves the write lock in force until the first
- * unlock. It also reference counts the locks. This means the following sequence :
- *
- * process1 process2
- * ------------------------------------------------------------------------
- * WRITE LOCK : start = 0, len = 10
- * READ LOCK: start =0, len = 10 - FAIL
- * READ LOCK : start = 5, len = 2
- * READ LOCK: start =0, len = 10 - FAIL
- * UNLOCK : start = 0, len = 10
- * READ LOCK: start =0, len = 10 - OK
- *
- * Under POSIX, the same sequence in steps 1 and 2 would not be reference counted, but
- * would leave a single read lock over the 0-10 region. In order to
- * re-create Windows semantics mapped to POSIX locks, we create multiple TDB
- * entries, one for each overlayed lock request. We are guarenteed by the brlock
- * semantics that if a write lock is added, then it will be first in the array.
- */
-
dbuf.dptr = NULL;
dbuf = tdb_fetch(posix_lock_tdb, kbuf);
- count = (size_t)(dbuf.dsize / sizeof(pl));
- entries = (struct posix_lock *)dbuf.dptr;
-
- /*
- * Ensure we look for overlapping entries *before*
- * we add this entry. Count the number of entries
- * that completely overlap this request.
- */
-
- for (i = 0; i < count; i++) {
- struct posix_lock *entry = &entries[i];
-
- if (fsp->fd == entry->fd &&
- start >= entry->start &&
- start + size <= entry->start + entry->size)
- num_overlapping_records++;
- }
+ *pentry_num = (size_t)(dbuf.dsize / sizeof(pl));
/*
* Add new record.
memcpy(dbuf.dptr + dbuf.dsize, &pl, sizeof(pl));
dbuf.dsize += sizeof(pl);
- *entry_num = count;
-
if (tdb_store(posix_lock_tdb, kbuf, dbuf, TDB_REPLACE) == -1) {
DEBUG(0,("add_posix_lock: Failed to add lock entry on file %s\n", fsp->fsp_name));
goto fail;
free(dbuf.dptr);
- DEBUG(10,("add_posix_lock: File %s: type = %s: start=%.0f size=%.0f: num_records = %d : dev=%.0f inode=%.0f\n",
- fsp->fsp_name, posix_lock_type_name(lock_type), (double)start, (double)size, num_overlapping_records,
+ DEBUG(10,("add_posix_lock: File %s: type = %s: start=%.0f size=%.0f: dev=%.0f inode=%.0f\n",
+ fsp->fsp_name, posix_lock_type_name(lock_type), (double)start, (double)size,
(double)fsp->dev, (double)fsp->inode ));
- return num_overlapping_records;
+ return True;
fail:
if (dbuf.dptr)
free(dbuf.dptr);
- *entry_num = 0;
- return -1;
+ return False;
+}
+
+/****************************************************************************
+ Calculate if locks have any overlap at all.
+****************************************************************************/
+
+static BOOL does_lock_overlap(SMB_OFF_T start1, SMB_OFF_T size1, SMB_OFF_T start2, SMB_OFF_T size2)
+{
+ if (start1 >= start2 && start1 <= start2 + size2)
+ return True;
+
+ if (start1 < start2 && start1 + size1 > start2);
+ return True;
+
+ return False;
}
/****************************************************************************
Delete an entry from the POSIX locking tdb. Returns a copy of the entry being
- deleted and the number of records that are completely overlapped by this one,
- or -1 on error.
+ deleted and the number of records that are overlapped by this one, or -1 on error.
****************************************************************************/
static int delete_posix_lock_entry(files_struct *fsp, SMB_OFF_T start, SMB_OFF_T size, struct posix_lock *pl)
/*
* Count the number of entries that are
- * overlapped completely by this unlock request.
- * (Note that this is the reverse of the test in
- * add_posix_lock).
+ * overlapped by this unlock request.
*/
for (i = 0; i < count; i++) {
struct posix_lock *entry = &locks[i];
if (fsp->fd == entry->fd &&
- entry->start >= start &&
- entry->start + entry->size <= start + size)
+ does_lock_overlap( start, size, entry->start, entry->size))
num_overlapping_records++;
}
- DEBUG(10,("delete_posix_lock_entry: type = %s: start=%.0f size=%.0f, num_records = %d\n",
- posix_lock_type_name(pl->lock_type), (double)pl->start, (double)pl->size,
- (unsigned int)num_overlapping_records ));
+ DEBUG(10,("delete_posix_lock_entry: type = %s: start=%.0f size=%.0f, num_records = %d\n",
+ posix_lock_type_name(pl->lock_type), (double)pl->start, (double)pl->size,
+ (unsigned int)num_overlapping_records ));
if (dbuf.dptr)
free(dbuf.dptr);
static BOOL posix_lock_in_range(SMB_OFF_T *offset_out, SMB_OFF_T *count_out,
SMB_BIG_UINT u_offset, SMB_BIG_UINT u_count)
{
- SMB_OFF_T offset;
- SMB_OFF_T count;
-
-#if defined(LARGE_SMB_OFF_T) && !defined(HAVE_BROKEN_FCNTL64_LOCKS)
-
- SMB_OFF_T mask2 = ((SMB_OFF_T)0x4) << (SMB_OFF_T_BITS-4);
- SMB_OFF_T mask = (mask2<<1);
- SMB_OFF_T neg_mask = ~mask;
-
- /*
- * In this case SMB_OFF_T is 64 bits,
- * and the underlying system can handle 64 bit signed locks.
- * Cast to signed type.
- */
-
- offset = (SMB_OFF_T)u_offset;
- count = (SMB_OFF_T)u_count;
+ SMB_OFF_T offset = (SMB_OFF_T)u_offset;
+ SMB_OFF_T count = (SMB_OFF_T)u_count;
/*
- * Deal with a very common case of count of all ones.
- * (lock entire file).
+ * For the type of system we are, attempt to
+ * find the maximum positive lock offset as an SMB_OFF_T.
*/
- if(count == (SMB_OFF_T)-1)
- count &= ~mask;
+#if defined(LARGE_SMB_OFF_T) && !defined(HAVE_BROKEN_FCNTL64_LOCKS)
/*
- * POSIX lock ranges cannot be negative.
- * Fail if any combination becomes negative.
+ * In this case SMB_OFF_T is 64 bits,
+ * and the underlying system can handle 64 bit signed locks.
*/
- if(offset < 0 || count < 0 || (offset + count < 0)) {
- DEBUG(10,("posix_lock_in_range: negative range: offset = %.0f, count = %.0f. Ignoring lock.\n",
- (double)offset, (double)count ));
- return False;
- }
-
- /*
- * In this case SMB_OFF_T is 64 bits, the offset and count
- * fit within the positive range, and the underlying
- * system can handle 64 bit locks. Just return as the
- * cast values are ok.
- */
+ SMB_OFF_T mask2 = ((SMB_OFF_T)0x4) << (SMB_OFF_T_BITS-4);
+ SMB_OFF_T mask = (mask2<<1);
+ SMB_OFF_T max_positive_lock_offset = ~mask;
#else /* !LARGE_SMB_OFF_T || HAVE_BROKEN_FCNTL64_LOCKS */
/*
* In this case either SMB_OFF_T is 32 bits,
* or the underlying system cannot handle 64 bit signed locks.
- * Either way we have to try and mangle to fit within 31 bits.
- * This is difficult.
+ * All offsets & counts must be 2^31 or less.
*/
-#if defined(HAVE_BROKEN_FCNTL64_LOCKS)
+ SMB_OFF_T max_positive_lock_offset = 0x7FFFFFFF;
- /*
- * SMB_OFF_T is 64 bits, but we need to use 31 bits due to
- * broken large locking.
- */
+#endif /* !LARGE_SMB_OFF_T || HAVE_BROKEN_FCNTL64_LOCKS */
/*
- * Deal with a very common case of count of all ones.
- * (lock entire file).
+ * If the given offset was > max_positive_lock_offset then we cannot map this at all
+ * ignore this lock.
*/
- if(u_count == (SMB_BIG_UINT)-1)
- count = 0x7FFFFFFF;
-
- if(((u_offset >> 32) & 0xFFFFFFFF) || ((u_count >> 32) & 0xFFFFFFFF)) {
- DEBUG(10,("posix_lock_in_range: top 32 bits not zero. offset = %.0f, count = %.0f. Ignoring lock.\n",
- (double)u_offset, (double)u_count ));
- /* Top 32 bits of offset or count were not zero. */
+ if (u_offset & ~((SMB_BIG_UINT)max_positive_lock_offset)) {
+ DEBUG(10,("posix_lock_in_range: (offset = %.0f) offset > %.0f and we cannot handle this. Ignoring lock.\n",
+ (double)u_offset, (double)((SMB_BIG_UINT)max_positive_lock_offset) ));
return False;
}
- /* Cast from 64 bits unsigned to 64 bits signed. */
- offset = (SMB_OFF_T)u_offset;
- count = (SMB_OFF_T)u_count;
-
- /*
- * Check if we are within the 2^31 range.
- */
-
- {
- int32 low_offset = (int32)offset;
- int32 low_count = (int32)count;
-
- if(low_offset < 0 || low_count < 0 || (low_offset + low_count < 0)) {
- DEBUG(10,("posix_lock_in_range: not within 2^31 range. low_offset = %d, low_count = %d. Ignoring lock.\n",
- low_offset, low_count ));
- return False;
- }
- }
-
- /*
- * Ok - we can map from a 64 bit number to a 31 bit lock.
- */
-
-#else /* HAVE_BROKEN_FCNTL64_LOCKS */
-
/*
- * SMB_OFF_T is 32 bits.
+ * We must truncate the offset and count to less than max_positive_lock_offset.
*/
-#if defined(HAVE_LONGLONG)
+ offset &= max_positive_lock_offset;
+ count &= max_positive_lock_offset;
- /*
- * SMB_BIG_UINT is 64 bits, we can do a 32 bit shift.
- */
/*
* Deal with a very common case of count of all ones.
* (lock entire file).
*/
- if(u_count == (SMB_BIG_UINT)-1)
- count = 0x7FFFFFFF;
-
- if(((u_offset >> 32) & 0xFFFFFFFF) || ((u_count >> 32) & 0xFFFFFFFF)) {
- DEBUG(10,("posix_lock_in_range: top 32 bits not zero. u_offset = %.0f, u_count = %.0f. Ignoring lock.\n",
- (double)u_offset, (double)u_count ));
- return False;
- }
-
- /* Cast from 64 bits unsigned to 32 bits signed. */
- offset = (SMB_OFF_T)u_offset;
- count = (SMB_OFF_T)u_count;
-
- /*
- * Check if we are within the 2^31 range.
- */
-
- if(offset < 0 || count < 0 || (offset + count < 0)) {
- DEBUG(10,("posix_lock_in_range: not within 2^31 range. offset = %d, count = %d. Ignoring lock.\n",
- (int)offset, (int)count ));
- return False;
- }
-
-#else /* HAVE_LONGLONG */
-
- /*
- * SMB_BIG_UINT and SMB_OFF_T are both 32 bits,
- * just cast.
- */
+ if(count == (SMB_OFF_T)-1)
+ count = max_positive_lock_offset;
/*
- * Deal with a very common case of count of all ones.
- * (lock entire file).
+ * Truncate count to end at max lock offset.
*/
- if(u_count == (SMB_BIG_UINT)-1)
- count = 0x7FFFFFFF;
-
- /* Cast from 32 bits unsigned to 32 bits signed. */
- offset = (SMB_OFF_T)u_offset;
- count = (SMB_OFF_T)u_count;
+ if (offset + count < 0 || offset + count > max_positive_lock_offset)
+ count = max_positive_lock_offset - offset;
/*
- * Check if we are within the 2^31 range.
+ * If we ate all the count, ignore this lock.
*/
- if(offset < 0 || count < 0 || (offset + count < 0)) {
- DEBUG(10,("posix_lock_in_range: not within 2^31 range. offset = %d, count = %d. Ignoring lock.\n",
- (int)offset, (int)count ));
+ if (count == 0) {
+ DEBUG(10,("posix_lock_in_range: Count = 0. Ignoring lock u_offset = %.0f, u_count = %.0f\n",
+ (double)u_offset, (double)u_count ));
return False;
}
-#endif /* HAVE_LONGLONG */
-#endif /* LARGE_SMB_OFF_T */
-#endif /* !LARGE_SMB_OFF_T || HAVE_BROKEN_FCNTL64_LOCKS */
-
/*
* The mapping was successful.
*/
return posix_fcntl_lock(fsp,SMB_F_GETLK,offset,count,posix_lock_type);
}
-/****************************************************************************
- POSIX function to acquire a lock. Returns True if the
- lock could be granted, False if not.
-****************************************************************************/
-
-BOOL set_posix_lock(files_struct *fsp, SMB_BIG_UINT u_offset, SMB_BIG_UINT u_count, enum brl_type lock_type)
-{
- SMB_OFF_T offset;
- SMB_OFF_T count;
- BOOL ret = True;
- size_t entry_num = 0;
- int posix_lock_type = map_posix_lock_type(fsp,lock_type);
- int num_overlapping_records;
-
- DEBUG(5,("set_posix_lock: File %s, offset = %.0f, count = %.0f, type = %s\n",
- fsp->fsp_name, (double)u_offset, (double)u_count, posix_lock_type_name(lock_type) ));
-
- /*
- * If the requested lock won't fit in the POSIX range, we will
- * pretend it was successful.
- */
-
- if(!posix_lock_in_range(&offset, &count, u_offset, u_count))
- return True;
-
- /*
- * Note that setting multiple overlapping locks on different
- * file descriptors will not be held separately by the kernel (POSIX
- * braindamage), but will be merged into one continuous lock
- * range. We cope with this case in the release_posix_lock code
- * below. We need to add the posix lock entry into the tdb before
- * doing the real posix lock call to deal with the locking overlay
- * case described above in add_posix_lock_entry().
- */
-
- num_overlapping_records = add_posix_lock_entry(fsp,offset,count,posix_lock_type,&entry_num);
-
- if (num_overlapping_records == -1) {
- DEBUG(0,("set_posix_lock: Unable to create posix lock entry !\n"));
- return False;
- }
-
- /*
- * num_overlapping_records is the count of lock records that
- * completely contain this request on the same fsp. Only bother
- * with the real lock request if there are none, otherwise ignore.
- */
-
- if (num_overlapping_records == 0) {
- /*
- * First lock entry for this range created. Do a real POSIX lock.
- */
- ret = posix_fcntl_lock(fsp,SMB_F_SETLK,offset,count,posix_lock_type);
-
- /*
- * Oops, POSIX lock failed, delete the tdb entry we just added.
- */
- if (!ret)
- delete_posix_lock_entry_by_index(fsp,entry_num);
- }
-
- return ret;
-}
-
/*
* Structure used when splitting a lock range
* into a POSIX lock range. Doubly linked list.
*/
-struct unlock_list {
- struct unlock_list *next;
- struct unlock_list *prev;
+struct lock_list {
+ struct lock_list *next;
+ struct lock_list *prev;
SMB_OFF_T start;
SMB_OFF_T size;
};
/****************************************************************************
Create a list of lock ranges that don't overlap a given range. Used in calculating
- POSIX lock unlocks. This is a difficult function that requires ASCII art to
+ POSIX locks and unlocks. This is a difficult function that requires ASCII art to
understand it :-).
****************************************************************************/
-static struct unlock_list *posix_unlock_list(TALLOC_CTX *ctx, struct unlock_list *ulhead, files_struct *fsp)
+static struct lock_list *posix_lock_list(TALLOC_CTX *ctx, struct lock_list *lhead, files_struct *fsp)
{
TDB_DATA kbuf = locking_key_fsp(fsp);
TDB_DATA dbuf;
dbuf = tdb_fetch(posix_lock_tdb, kbuf);
- if (!dbuf.dptr) {
- return ulhead;
- }
+ if (!dbuf.dptr)
+ return lhead;
locks = (struct posix_lock *)dbuf.dptr;
num_locks = (size_t)(dbuf.dsize / sizeof(*locks));
* Quit if the list is deleted.
*/
- DEBUG(10,("posix_unlock_list: curr: start=%.0f,size=%.0f\n",
- (double)ulhead->start, (double)ulhead->size ));
+ DEBUG(10,("posix_lock_list: curr: start=%.0f,size=%.0f\n",
+ (double)lhead->start, (double)lhead->size ));
- for (i=0; i<num_locks && ulhead; i++) {
+ for (i=0; i<num_locks && lhead; i++) {
struct posix_lock *lock = &locks[i];
- struct unlock_list *ul_curr;
+ struct lock_list *l_curr;
/*
- * Walk the unlock list, checking for overlaps. Note that
- * the unlock list can expand within this loop if the current
+ * Walk the lock list, checking for overlaps. Note that
+ * the lock list can expand within this loop if the current
* range being examined needs to be split.
*/
- for (ul_curr = ulhead; ul_curr;) {
+ for (l_curr = lhead; l_curr;) {
- DEBUG(10,("posix_unlock_list: lock: fd=%d: start=%.0f,size=%.0f:type=%s", lock->fd,
+ DEBUG(10,("posix_lock_list: lock: fd=%d: start=%.0f,size=%.0f:type=%s", lock->fd,
(double)lock->start, (double)lock->size, posix_lock_type_name(lock->lock_type) ));
- if ( (ul_curr->start >= (lock->start + lock->size)) ||
- (lock->start >= (ul_curr->start + ul_curr->size))) {
+ if ( (l_curr->start >= (lock->start + lock->size)) ||
+ (lock->start >= (l_curr->start + l_curr->size))) {
/* No overlap with this lock - leave this range alone. */
/*********************************************
+---------+
- | ul_curr |
+ | l_curr |
+---------+
+-------+
| lock |
+-------+
OR....
+---------+
- | ul_curr |
+ | l_curr |
+---------+
**********************************************/
DEBUG(10,("no overlap case.\n" ));
- ul_curr = ul_curr->next;
+ l_curr = l_curr->next;
- } else if ( (ul_curr->start >= lock->start) &&
- (ul_curr->start + ul_curr->size <= lock->start + lock->size) ) {
+ } else if ( (l_curr->start >= lock->start) &&
+ (l_curr->start + l_curr->size <= lock->start + lock->size) ) {
/*
* This unlock is completely overlapped by this existing lock range
*/
/*********************************************
+---------+
- | ul_curr |
+ | l_curr |
+---------+
+---------------------------+
| lock |
+---------------------------+
**********************************************/
/* Save the next pointer */
- struct unlock_list *ul_next = ul_curr->next;
+ struct lock_list *ul_next = l_curr->next;
DEBUG(10,("delete case.\n" ));
- DLIST_REMOVE(ulhead, ul_curr);
- if(ulhead == NULL)
+ DLIST_REMOVE(lhead, l_curr);
+ if(lhead == NULL)
break; /* No more list... */
- ul_curr = ul_next;
+ l_curr = ul_next;
- } else if ( (ul_curr->start >= lock->start) &&
- (ul_curr->start < lock->start + lock->size) &&
- (ul_curr->start + ul_curr->size > lock->start + lock->size) ) {
+ } else if ( (l_curr->start >= lock->start) &&
+ (l_curr->start < lock->start + lock->size) &&
+ (l_curr->start + l_curr->size > lock->start + lock->size) ) {
/*
* This unlock overlaps the existing lock range at the high end.
*/
/*********************************************
+---------------+
- | ul_curr |
+ | l_curr |
+---------------+
+---------------+
| lock |
+---------------+
BECOMES....
+-------+
- |ul_curr|
+ | l_curr|
+-------+
**********************************************/
- ul_curr->size = (ul_curr->start + ul_curr->size) - (lock->start + lock->size);
- ul_curr->start = lock->start + lock->size;
+ l_curr->size = (l_curr->start + l_curr->size) - (lock->start + lock->size);
+ l_curr->start = lock->start + lock->size;
DEBUG(10,("truncate high case: start=%.0f,size=%.0f\n",
- (double)ul_curr->start, (double)ul_curr->size ));
+ (double)l_curr->start, (double)l_curr->size ));
- ul_curr = ul_curr->next;
+ l_curr = l_curr->next;
- } else if ( (ul_curr->start < lock->start) &&
- (ul_curr->start + ul_curr->size > lock->start) &&
- (ul_curr->start + ul_curr->size <= lock->start + lock->size) ) {
+ } else if ( (l_curr->start < lock->start) &&
+ (l_curr->start + l_curr->size > lock->start) &&
+ (l_curr->start + l_curr->size <= lock->start + lock->size) ) {
/*
* This unlock overlaps the existing lock range at the low end.
*/
/*********************************************
+---------------+
- | ul_curr |
+ | l_curr |
+---------------+
+---------------+
| lock |
+---------------+
BECOMES....
+-------+
- |ul_curr|
+ | l_curr|
+-------+
**********************************************/
- ul_curr->size = lock->start - ul_curr->start;
+ l_curr->size = lock->start - l_curr->start;
DEBUG(10,("truncate low case: start=%.0f,size=%.0f\n",
- (double)ul_curr->start, (double)ul_curr->size ));
+ (double)l_curr->start, (double)l_curr->size ));
- ul_curr = ul_curr->next;
+ l_curr = l_curr->next;
- } else if ( (ul_curr->start < lock->start) &&
- (ul_curr->start + ul_curr->size > lock->start + lock->size) ) {
+ } else if ( (l_curr->start < lock->start) &&
+ (l_curr->start + l_curr->size > lock->start + lock->size) ) {
/*
* Worst case scenario. Unlock request completely overlaps an existing
* lock range. Split the request into two, push the new (upper) request
*/
/*********************************************
+---------------------------+
- | ul_curr |
+ | l_curr |
+---------------------------+
+---------+
| lock |
+---------+
BECOMES.....
+-------+ +---------+
- |ul_curr| |ul_new |
+ | l_curr| | l_new |
+-------+ +---------+
**********************************************/
- struct unlock_list *ul_new = (struct unlock_list *)talloc(ctx,
- sizeof(struct unlock_list));
+ struct lock_list *l_new = (struct lock_list *)talloc(ctx,
+ sizeof(struct lock_list));
- if(ul_new == NULL) {
- DEBUG(0,("posix_unlock_list: talloc fail.\n"));
+ if(l_new == NULL) {
+ DEBUG(0,("posix_lock_list: talloc fail.\n"));
return NULL; /* The talloc_destroy takes care of cleanup. */
}
- ZERO_STRUCTP(ul_new);
- ul_new->start = lock->start + lock->size;
- ul_new->size = ul_curr->start + ul_curr->size - ul_new->start;
+ ZERO_STRUCTP(l_new);
+ l_new->start = lock->start + lock->size;
+ l_new->size = l_curr->start + l_curr->size - l_new->start;
- /* Truncate the ul_curr. */
- ul_curr->size = lock->start - ul_curr->start;
+ /* Truncate the l_curr. */
+ l_curr->size = lock->start - l_curr->start;
DEBUG(10,("split case: curr: start=%.0f,size=%.0f \
-new: start=%.0f,size=%.0f\n", (double)ul_curr->start, (double)ul_curr->size,
- (double)ul_new->start, (double)ul_new->size ));
+new: start=%.0f,size=%.0f\n", (double)l_curr->start, (double)l_curr->size,
+ (double)l_new->start, (double)l_new->size ));
/*
- * Add into the dlink list after the ul_curr point - NOT at ulhead.
+ * Add into the dlink list after the l_curr point - NOT at lhead.
* Note we can't use DLINK_ADD here as this inserts at the head of the given list.
*/
- ul_new->prev = ul_curr;
- ul_new->next = ul_curr->next;
- ul_curr->next = ul_new;
+ l_new->prev = l_curr;
+ l_new->next = l_curr->next;
+ l_curr->next = l_new;
/* And move after the link we added. */
- ul_curr = ul_new->next;
+ l_curr = l_new->next;
} else {
*/
pstring msg;
- slprintf(msg, sizeof(msg)-1, "logic flaw in cases: ul_curr: start = %.0f, size = %.0f : \
-lock: start = %.0f, size = %.0f\n", (double)ul_curr->start, (double)ul_curr->size, (double)lock->start, (double)lock->size );
+ slprintf(msg, sizeof(msg)-1, "logic flaw in cases: l_curr: start = %.0f, size = %.0f : \
+lock: start = %.0f, size = %.0f\n", (double)l_curr->start, (double)l_curr->size, (double)lock->start, (double)lock->size );
smb_panic(msg);
}
- } /* end for ( ul_curr = ulhead; ul_curr;) */
+ } /* end for ( l_curr = lhead; l_curr;) */
} /* end for (i=0; i<num_locks && ul_head; i++) */
if (dbuf.dptr)
free(dbuf.dptr);
- return ulhead;
+ return lhead;
+}
+
+/****************************************************************************
+ POSIX function to acquire a lock. Returns True if the
+ lock could be granted, False if not.
+****************************************************************************/
+
+BOOL set_posix_lock(files_struct *fsp, SMB_BIG_UINT u_offset, SMB_BIG_UINT u_count, enum brl_type lock_type)
+{
+ SMB_OFF_T offset;
+ SMB_OFF_T count;
+ BOOL ret = True;
+ size_t entry_num = 0;
+ size_t lock_count;
+ TALLOC_CTX *l_ctx = NULL;
+ struct lock_list *llist = NULL;
+ struct lock_list *ll = NULL;
+ int posix_lock_type = map_posix_lock_type(fsp,lock_type);
+
+ DEBUG(5,("set_posix_lock: File %s, offset = %.0f, count = %.0f, type = %s\n",
+ fsp->fsp_name, (double)u_offset, (double)u_count, posix_lock_type_name(lock_type) ));
+
+ /*
+ * If the requested lock won't fit in the POSIX range, we will
+ * pretend it was successful.
+ */
+
+ if(!posix_lock_in_range(&offset, &count, u_offset, u_count))
+ return True;
+
+ /*
+ * Windows is very strange. It allows read locks to be overlayed
+ * (even over a write lock), but leaves the write lock in force until the first
+ * unlock. It also reference counts the locks. This means the following sequence :
+ *
+ * process1 process2
+ * ------------------------------------------------------------------------
+ * WRITE LOCK : start = 2, len = 10
+ * READ LOCK: start =0, len = 10 - FAIL
+ * READ LOCK : start = 0, len = 14
+ * READ LOCK: start =0, len = 10 - FAIL
+ * UNLOCK : start = 2, len = 10
+ * READ LOCK: start =0, len = 10 - OK
+ *
+ * Under POSIX, the same sequence in steps 1 and 2 would not be reference counted, but
+ * would leave a single read lock over the 0-14 region. In order to
+ * re-create Windows semantics mapped to POSIX locks, we create multiple TDB
+ * entries, one for each overlayed lock request. We are guarenteed by the brlock
+ * semantics that if a write lock is added, then it will be first in the array.
+ */
+
+ if ((l_ctx = talloc_init()) == NULL) {
+ DEBUG(0,("set_posix_lock: unable to init talloc context.\n"));
+ return True; /* Not a fatal error. */
+ }
+
+ if ((ll = (struct lock_list *)talloc(l_ctx, sizeof(struct lock_list))) == NULL) {
+ DEBUG(0,("set_posix_lock: unable to talloc unlock list.\n"));
+ talloc_destroy(l_ctx);
+ return True; /* Not a fatal error. */
+ }
+
+ /*
+ * Create the initial list entry containing the
+ * lock we want to add.
+ */
+
+ ZERO_STRUCTP(ll);
+ ll->start = offset;
+ ll->size = count;
+
+ DLIST_ADD(llist, ll);
+
+ /*
+ * The following call calculates if there are any
+ * overlapping locks held by this process on
+ * fd's open on the same file and splits this list
+ * into a list of lock ranges that do not overlap with existing
+ * POSIX locks.
+ */
+
+ llist = posix_lock_list(l_ctx, llist, fsp);
+
+ /*
+ * Now we have the list of ranges to lock it is safe to add the
+ * entry into the POSIX lock tdb. We take note of the entry we
+ * added here in case we have to remove it on POSIX lock fail.
+ */
+
+ if (!add_posix_lock_entry(fsp,offset,count,posix_lock_type,&entry_num)) {
+ DEBUG(0,("set_posix_lock: Unable to create posix lock entry !\n"));
+ talloc_destroy(l_ctx);
+ return False;
+ }
+
+ /*
+ * Add the POSIX locks on the list of ranges returned.
+ * As the lock is supposed to be added atomically, we need to
+ * back out all the locks if any one of these calls fail.
+ */
+
+ for (lock_count = 0, ll = llist; ll; ll = ll->next, lock_count++) {
+ offset = ll->start;
+ count = ll->size;
+
+ DEBUG(5,("set_posix_lock: Real lock: Type = %s: offset = %.0f, count = %.0f\n",
+ posix_lock_type_name(posix_lock_type), (double)offset, (double)count ));
+
+ if (!posix_fcntl_lock(fsp,SMB_F_SETLK,offset,count,posix_lock_type)) {
+ DEBUG(5,("set_posix_lock: Lock fail !: Type = %s: offset = %.0f, count = %.0f\n",
+ posix_lock_type_name(posix_lock_type), (double)offset, (double)count ));
+ ret = False;
+ break;
+ }
+ }
+
+ if (!ret) {
+
+ /*
+ * Back out all the POSIX locks we have on fail.
+ */
+
+ for (ll = llist; lock_count; ll = ll->next, lock_count--) {
+ offset = ll->start;
+ count = ll->size;
+
+ DEBUG(5,("set_posix_lock: Backing out locks: Type = %s: offset = %.0f, count = %.0f\n",
+ posix_lock_type_name(posix_lock_type), (double)offset, (double)count ));
+
+ posix_fcntl_lock(fsp,SMB_F_SETLK,offset,count,F_UNLCK);
+ }
+
+ /*
+ * Remove the tdb entry for this lock.
+ */
+
+ delete_posix_lock_entry_by_index(fsp,entry_num);
+ }
+
+ talloc_destroy(l_ctx);
+ return ret;
}
/****************************************************************************
SMB_OFF_T count;
BOOL ret = True;
TALLOC_CTX *ul_ctx = NULL;
- struct unlock_list *ulist = NULL;
- struct unlock_list *ul = NULL;
+ struct lock_list *ulist = NULL;
+ struct lock_list *ul = NULL;
struct posix_lock deleted_lock;
int num_overlapped_entries;
/*
* We treat this as one unlock request for POSIX accounting purposes even
* if it may later be split into multiple smaller POSIX unlock ranges.
+ * num_overlapped_entries is the number of existing locks that have any
+ * overlap with this unlock request.
*/
num_overlapped_entries = delete_posix_lock_entry(fsp, offset, count, &deleted_lock);
/*
* If num_overlapped_entries is > 0, and the lock_type we just deleted from the tdb was
* a POSIX write lock, then before doing the unlock we need to downgrade
- * the POSIX lock to a read lock.
+ * the POSIX lock to a read lock. This allows any overlapping read locks
+ * to be atomically maintained.
*/
if (num_overlapped_entries > 0 && deleted_lock.lock_type == F_WRLCK) {
}
if ((ul_ctx = talloc_init()) == NULL) {
- DEBUG(0,("release_posix_lock: unable to init talloc context.\n"));
+ DEBUG(0,("release_posix_lock: unable to init talloc context.\n"));
return True; /* Not a fatal error. */
}
- if ((ul = (struct unlock_list *)talloc(ul_ctx, sizeof(struct unlock_list))) == NULL) {
+ if ((ul = (struct lock_list *)talloc(ul_ctx, sizeof(struct lock_list))) == NULL) {
DEBUG(0,("release_posix_lock: unable to talloc unlock list.\n"));
talloc_destroy(ul_ctx);
return True; /* Not a fatal error. */
* unlocks are performed.
*/
- ulist = posix_unlock_list(ul_ctx, ulist, fsp);
+ ulist = posix_lock_list(ul_ctx, ulist, fsp);
/*
* Release the POSIX locks on the list of ranges returned.
offset = ulist->start;
count = ulist->size;
- if(u_count == 0) {
-
- /*
- * This lock must overlap with an existing lock.
- * Don't do any POSIX call.
- */
-
- continue;
- }
-
DEBUG(5,("release_posix_lock: Real unlock: offset = %.0f, count = %.0f\n",
(double)offset, (double)count ));
git.samba.org / nivanova / samba-autobuild / .git / commitdiff