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|
/*
Unix SMB/Netbios implementation.
Version 3.0
Locking functions
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.
Revision History:
POSIX locking support. Jeremy Allison (jeremy@valinux.com), Apr. 2000.
*/
#include "includes.h"
extern int DEBUGLEVEL;
extern int global_smbpid;
/*
* The POSIX locking database handle.
*/
static TDB_CONTEXT *posix_lock_tdb;
/*
* The pending close database handle.
*/
static TDB_CONTEXT *posix_pending_close_tdb;
/*
* The data in POSIX lock 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 posix_lock {
int fd;
SMB_OFF_T start;
SMB_OFF_T size;
int lock_type;
};
/*
* The data in POSIX pending close records is an unsorted linear array of int
* records. It is unnecessary to store the count as tdb provides the
* size of the record.
*/
/* The key used in both the POSIX databases. */
struct posix_lock_key {
SMB_DEV_T device;
SMB_INO_T inode;
};
/*******************************************************************
Form a static locking key for a dev/inode pair.
******************************************************************/
static TDB_DATA locking_key(SMB_DEV_T dev, SMB_INO_T inode)
{
static struct posix_lock_key key;
TDB_DATA kbuf;
key.device = dev;
key.inode = inode;
kbuf.dptr = (char *)&key;
kbuf.dsize = sizeof(key);
return kbuf;
}
/*******************************************************************
Convenience function to get a key from an fsp.
******************************************************************/
static TDB_DATA locking_key_fsp(files_struct *fsp)
{
return locking_key(fsp->dev, fsp->inode);
}
/****************************************************************************
Add an fd to the pending close tdb.
****************************************************************************/
static BOOL add_fd_to_close_entry(files_struct *fsp)
{
TDB_DATA kbuf = locking_key_fsp(fsp);
TDB_DATA dbuf;
dbuf.dptr = NULL;
dbuf = tdb_fetch(posix_pending_close_tdb, kbuf);
dbuf.dptr = Realloc(dbuf.dptr, dbuf.dsize + sizeof(int));
if (!dbuf.dptr) {
DEBUG(0,("add_fd_to_close_entry: Realloc fail !\n"));
return False;
}
memcpy(dbuf.dptr + dbuf.dsize, &fsp->fd, sizeof(int));
dbuf.dsize += sizeof(int);
if (tdb_store(posix_pending_close_tdb, kbuf, dbuf, TDB_REPLACE) == -1) {
DEBUG(0,("add_fd_to_close_entry: tdb_store fail !\n"));
}
free(dbuf.dptr);
return True;
}
/****************************************************************************
Remove all fd entries for a specific dev/inode pair from the tdb.
****************************************************************************/
static void delete_close_entries(files_struct *fsp)
{
TDB_DATA kbuf = locking_key_fsp(fsp);
if (tdb_delete(posix_pending_close_tdb, kbuf) == -1)
DEBUG(0,("delete_close_entries: tdb_delete fail !\n"));
}
/****************************************************************************
Get the array of POSIX pending close records for an open fsp. Caller must
free. Returns number of entries.
****************************************************************************/
static size_t get_posix_pending_close_entries(files_struct *fsp, int **entries)
{
TDB_DATA kbuf = locking_key_fsp(fsp);
TDB_DATA dbuf;
size_t count = 0;
*entries = NULL;
dbuf.dptr = NULL;
dbuf = tdb_fetch(posix_pending_close_tdb, kbuf);
if (!dbuf.dptr) {
return 0;
}
*entries = (int *)dbuf.dptr;
count = (size_t)(dbuf.dsize / sizeof(int));
return count;
}
/****************************************************************************
Get the array of POSIX locks for an fsp. Caller must free. Returns
number of entries.
****************************************************************************/
static size_t get_posix_lock_entries(files_struct *fsp, struct posix_lock **entries)
{
TDB_DATA kbuf = locking_key_fsp(fsp);
TDB_DATA dbuf;
size_t count = 0;
*entries = NULL;
dbuf.dptr = NULL;
dbuf = tdb_fetch(posix_lock_tdb, kbuf);
if (!dbuf.dptr) {
return 0;
}
*entries = (struct posix_lock *)dbuf.dptr;
count = (size_t)(dbuf.dsize / sizeof(struct posix_lock));
return count;
}
/****************************************************************************
Deal with pending closes needed by POSIX locking support.
****************************************************************************/
int fd_close_posix(struct connection_struct *conn, files_struct *fsp)
{
int saved_errno = 0;
int ret;
size_t count, i;
struct posix_lock *entries = NULL;
int *fd_array = NULL;
if (!lp_posix_locking(SNUM(conn))) {
/*
* No POSIX to worry about, just close.
*/
ret = conn->vfs_ops.close(fsp->fd);
fsp->fd = -1;
return ret;
}
/*
* Get the number of outstanding POSIX locks on this dev/inode pair.
*/
count = get_posix_lock_entries(fsp, &entries);
if (count) {
/*
* There are outstanding locks on this dev/inode pair on other fds.
* Add our fd to the pending close tdb and set fsp->fd to -1.
*/
if (!add_fd_to_close_entry(fsp)) {
free((char *)entries);
return False;
}
free((char *)entries);
fsp->fd = -1;
return 0;
}
if(entries)
free((char *)entries);
/*
* No outstanding POSIX locks. Get the pending close fd's
* from the tdb and close them all.
*/
count = get_posix_pending_close_entries(fsp, &fd_array);
if (count) {
DEBUG(10,("fd_close_posix: doing close on %u fd's.\n", (unsigned int)count ));
for(i = 0; i < count; i++) {
if (conn->vfs_ops.close(fd_array[i]) == -1) {
saved_errno = errno;
}
}
if (fd_array)
free((char *)fd_array);
/*
* Delete all fd's stored in the tdb
* for this dev/inode pair.
*/
delete_close_entries(fsp);
}
if (fd_array)
free((char *)fd_array);
/*
* Finally close the fd associated with this fsp.
*/
ret = conn->vfs_ops.close(fsp->fd);
if (saved_errno != 0) {
errno = saved_errno;
ret = -1;
}
fsp->fd = -1;
return ret;
}
/****************************************************************************
Debugging aid :-).
****************************************************************************/
static const char *posix_lock_type_name(int lock_type)
{
return (lock_type == F_RDLCK) ? "READ" : "WRITE";
}
/****************************************************************************
Add an entry into the POSIX locking tdb.
****************************************************************************/
static BOOL add_posix_lock_entry(files_struct *fsp, SMB_OFF_T start, SMB_OFF_T size, int lock_type)
{
TDB_DATA kbuf = locking_key_fsp(fsp);
TDB_DATA dbuf;
struct posix_lock pl;
/*
* Now setup the new record.
*/
pl.fd = fsp->fd;
pl.start = start;
pl.size = size;
pl.lock_type = lock_type;
dbuf.dptr = NULL;
dbuf = tdb_fetch(posix_lock_tdb, kbuf);
dbuf.dptr = Realloc(dbuf.dptr, dbuf.dsize + sizeof(pl));
if (!dbuf.dptr) {
DEBUG(0,("add_posix_lock_entry: Realloc fail !\n"));
goto fail;
}
memcpy(dbuf.dptr + dbuf.dsize, &pl, sizeof(pl));
dbuf.dsize += sizeof(pl);
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: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 True;
fail:
if (dbuf.dptr)
free(dbuf.dptr);
return False;
}
/****************************************************************************
Delete an entry from the POSIX locking tdb.
****************************************************************************/
static BOOL delete_posix_lock_entry(files_struct *fsp, SMB_OFF_T start, SMB_OFF_T size)
{
TDB_DATA kbuf = locking_key_fsp(fsp);
TDB_DATA dbuf;
struct posix_lock *locks;
size_t i, count;
dbuf.dptr = NULL;
dbuf = tdb_fetch(posix_lock_tdb, kbuf);
if (!dbuf.dptr) {
DEBUG(10,("delete_posix_lock_entry: tdb_fetch failed !\n"));
goto fail;
}
/* There are existing locks - find a match. */
locks = (struct posix_lock *)dbuf.dptr;
count = (size_t)(dbuf.dsize / sizeof(*locks));
for (i=0; i<count; i++) {
struct posix_lock *pl = &locks[i];
if (pl->fd == fsp->fd &&
pl->start == start &&
pl->size == size) {
/* Found it - delete it. */
if (count == 1) {
tdb_delete(posix_lock_tdb, kbuf);
} else {
if (i < count-1) {
memmove(&locks[i], &locks[i+1], sizeof(*locks)*((count-1) - i));
}
dbuf.dsize -= sizeof(*locks);
tdb_store(posix_lock_tdb, kbuf, dbuf, TDB_REPLACE);
}
free(dbuf.dptr);
return True;
}
}
/* We didn't find it. */
fail:
if (dbuf.dptr)
free(dbuf.dptr);
return False;
}
/****************************************************************************
Utility function to map a lock type correctly depending on the open
mode of a file.
****************************************************************************/
static int map_posix_lock_type( files_struct *fsp, enum brl_type lock_type)
{
if((lock_type == WRITE_LOCK) && !fsp->can_write) {
/*
* Many UNIX's cannot get a write lock on a file opened read-only.
* Win32 locking semantics allow this.
* Do the best we can and attempt a read-only lock.
*/
DEBUG(10,("map_posix_lock_type: Downgrading write lock to read due to read-only file.\n"));
return F_RDLCK;
} else if((lock_type == READ_LOCK) && !fsp->can_read) {
/*
* Ditto for read locks on write only files.
*/
DEBUG(10,("map_posix_lock_type: Changing read lock to write due to write-only file.\n"));
return F_WRLCK;
}
/*
* This return should be the most normal, as we attempt
* to always open files read/write.
*/
return (lock_type == READ_LOCK) ? F_RDLCK : F_WRLCK;
}
/****************************************************************************
Check to see if the given unsigned lock range is within the possible POSIX
range. Modifies the given args to be in range if possible, just returns
False if not.
****************************************************************************/
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;
/*
* Deal with a very common case of count of all ones.
* (lock entire file).
*/
if(count == (SMB_OFF_T)-1)
count &= ~mask;
/*
* POSIX lock ranges cannot be negative.
* Fail if any combination becomes negative.
*/
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.
*/
#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.
*/
#if defined(HAVE_BROKEN_FCNTL64_LOCKS)
/*
* SMB_OFF_T is 64 bits, but we need to use 31 bits due to
* broken large locking.
*/
/*
* 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. offset = %.0f, count = %.0f. Ignoring lock.\n",
(double)u_offset, (double)u_count ));
/* Top 32 bits of offset or count were not zero. */
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.
*/
#if defined(HAVE_LONGLONG)
/*
* 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.
*/
/*
* Deal with a very common case of count of all ones.
* (lock entire file).
*/
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;
/*
* 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;
}
#endif /* HAVE_LONGLONG */
#endif /* LARGE_SMB_OFF_T */
#endif /* !LARGE_SMB_OFF_T || HAVE_BROKEN_FCNTL64_LOCKS */
/*
* The mapping was successful.
*/
DEBUG(10,("posix_lock_in_range: offset_out = %.0f, count_out = %.0f\n",
(double)offset, (double)count ));
*offset_out = offset;
*count_out = count;
return True;
}
/****************************************************************************
POSIX function to see if a file region is locked. Returns True if the
region is locked, False otherwise.
****************************************************************************/
BOOL is_posix_locked(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;
int posix_lock_type = map_posix_lock_type(fsp,lock_type);
DEBUG(10,("is_posix_locked: 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
* never set it, so presume it is not locked.
*/
if(!posix_lock_in_range(&offset, &count, u_offset, u_count))
return False;
/*
* Note that most UNIX's can *test* for a write lock on
* a read-only fd, just not *set* a write lock on a read-only
* fd. So we don't need to use map_lock_type here.
*/
return fcntl_lock(fsp->fd,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;
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;
/*
* 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. JRA.
*/
ret = fcntl_lock(fsp->fd,SMB_F_SETLK,offset,count,posix_lock_type);
if (ret)
add_posix_lock_entry(fsp,offset,count,posix_lock_type);
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;
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
understand it :-).
****************************************************************************/
static struct unlock_list *posix_unlock_list(TALLOC_CTX *ctx, struct unlock_list *ulhead, files_struct *fsp)
{
TDB_DATA kbuf = locking_key_fsp(fsp);
TDB_DATA dbuf;
struct posix_lock *locks;
size_t num_locks, i;
dbuf.dptr = NULL;
dbuf = tdb_fetch(posix_lock_tdb, kbuf);
if (!dbuf.dptr) {
return ulhead;
}
locks = (struct posix_lock *)dbuf.dptr;
num_locks = (size_t)(dbuf.dsize / sizeof(*locks));
/*
* Check the current lock list on this dev/inode pair.
* Quit if the list is deleted.
*/
DEBUG(10,("posix_unlock_list: curr: start=%.0f,size=%.0f\n",
(double)ulhead->start, (double)ulhead->size ));
for (i=0; i<num_locks && ulhead; i++) {
struct posix_lock *lock = &locks[i];
struct unlock_list *ul_curr;
/*
* Walk the unlock list, checking for overlaps. Note that
* the unlock list can expand within this loop if the current
* range being examined needs to be split.
*/
for (ul_curr = ulhead; ul_curr;) {
DEBUG(10,("posix_unlock_list: lock: start=%.0f,size=%.0f:",
(double)lock->start, (double)lock->size ));
if ( (ul_curr->start >= (lock->start + lock->size)) ||
(lock->start > (ul_curr->start + ul_curr->size))) {
/* No overlap with this lock - leave this range alone. */
/*********************************************
+---------+
| ul_curr |
+---------+
+-------+
| lock |
+-------+
OR....
+---------+
| ul_curr |
+---------+
**********************************************/
DEBUG(10,("no overlap case.\n" ));
ul_curr = ul_curr->next;
} else if ( (ul_curr->start >= lock->start) &&
(ul_curr->start + ul_curr->size <= lock->start + lock->size) ) {
/*
* This unlock is completely overlapped by this existing lock range
* and thus should have no effect (not be unlocked). Delete it from the list.
*/
/*********************************************
+---------+
| ul_curr |
+---------+
+---------------------------+
| lock |
+---------------------------+
**********************************************/
/* Save the next pointer */
struct unlock_list *ul_next = ul_curr->next;
DEBUG(10,("delete case.\n" ));
DLIST_REMOVE(ulhead, ul_curr);
if(ulhead == NULL)
break; /* No more list... */
ul_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) ) {
/*
* This unlock overlaps the existing lock range at the high end.
* Truncate by moving start to existing range end and reducing size.
*/
/*********************************************
+---------------+
| ul_curr |
+---------------+
+---------------+
| lock |
+---------------+
BECOMES....
+-------+
|ul_curr|
+-------+
**********************************************/
ul_curr->size = (ul_curr->start + ul_curr->size) - (lock->start + lock->size);
ul_curr->start = lock->start + lock->size;
DEBUG(10,("truncate high case: start=%.0f,size=%.0f\n",
(double)ul_curr->start, (double)ul_curr->size ));
ul_curr = ul_curr->next;
} else if ( (ul_curr->start < lock->start) &&
(ul_curr->start + ul_curr->size > lock->start) ) {
/*
* This unlock overlaps the existing lock range at the low end.
* Truncate by reducing size.
*/
/*********************************************
+---------------+
| ul_curr |
+---------------+
+---------------+
| lock |
+---------------+
BECOMES....
+-------+
|ul_curr|
+-------+
**********************************************/
ul_curr->size = lock->start - ul_curr->start;
DEBUG(10,("truncate low case: start=%.0f,size=%.0f\n",
(double)ul_curr->start, (double)ul_curr->size ));
ul_curr = ul_curr->next;
} else if ( (ul_curr->start < lock->start) &&
(ul_curr->start + ul_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
* into the dlink list, and continue with the entry after ul_new (as we
* know that ul_new will not overlap with this lock).
*/
/*********************************************
+---------------------------+
| ul_curr |
+---------------------------+
+---------+
| lock |
+---------+
BECOMES.....
+-------+ +---------+
|ul_curr| |ul_new |
+-------+ +---------+
**********************************************/
struct unlock_list *ul_new = (struct unlock_list *)talloc(ctx,
sizeof(struct unlock_list));
if(ul_new == NULL) {
DEBUG(0,("posix_unlock_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;
/* Add into the dlink list after the ul_curr point - NOT at ulhead. */
DLIST_ADD(ul_curr, ul_new);
/* Truncate the ul_curr. */
ul_curr->size = lock->start - ul_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 ));
ul_curr = ul_new->next;
} else {
/*
* This logic case should never happen. Ensure this is the
* case by forcing an abort.... Remove in production.
*/
smb_panic("logic flaw in cases...\n");
}
} /* end for ( ul_curr = ulhead; ul_curr;) */
} /* end for (i=0; i<num_locks && ul_head; i++) */
if (dbuf.dptr)
free(dbuf.dptr);
return ulhead;
}
/****************************************************************************
POSIX function to release a lock. Returns True if the
lock could be released, False if not.
****************************************************************************/
BOOL release_posix_lock(files_struct *fsp, SMB_BIG_UINT u_offset, SMB_BIG_UINT u_count)
{
SMB_OFF_T offset;
SMB_OFF_T count;
BOOL ret = True;
TALLOC_CTX *ul_ctx = NULL;
struct unlock_list *ulist = NULL;
struct unlock_list *ul = NULL;
DEBUG(5,("release_posix_lock: File %s, offset = %.0f, count = %.0f\n",
fsp->fsp_name, (double)u_offset, (double)u_count ));
/*
* 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;
/*
* We treat this as one unlock request for POSIX accounting purposes even
* if it may have been split into multiple smaller POSIX unlock ranges.
*/
delete_posix_lock_entry(fsp, offset, count);
if ((ul_ctx = talloc_init()) == NULL) {
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) {
DEBUG(0,("release_posix_lock: unable to talloc unlock list.\n"));
talloc_destroy(ul_ctx);
return True; /* Not a fatal error. */
}
/*
* Create the initial list entry containing the
* lock we want to remove.
*/
ZERO_STRUCTP(ul);
ul->start = offset;
ul->size = count;
DLIST_ADD(ulist, ul);
/*
* The following call calculates if there are any
* overlapping locks held by this process on
* fd's open on the same file and creates a
* list of unlock ranges that will allow
* POSIX lock ranges to remain on the file whilst the
* unlocks are performed.
*/
ulist = posix_unlock_list(ul_ctx, ulist, fsp);
/*
* Release the POSIX locks on the list of ranges returned.
*/
for(; ulist; ulist = ulist->next) {
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 ));
if (!fcntl_lock(fsp->fd,SMB_F_SETLK,offset,count,F_UNLCK))
ret = False;
}
talloc_destroy(ul_ctx);
return ret;
}
/****************************************************************************
Remove all lock entries for a specific dev/inode pair from the tdb.
****************************************************************************/
static void delete_posix_lock_entries(files_struct *fsp)
{
TDB_DATA kbuf = locking_key_fsp(fsp);
if (tdb_delete(posix_lock_tdb, kbuf) == -1)
DEBUG(0,("delete_close_entries: tdb_delete fail !\n"));
}
/****************************************************************************
Debug function.
****************************************************************************/
static void dump_entry(struct posix_lock *pl)
{
DEBUG(10,("entry: start=%.0f, size=%.0f, type=%d, fd=%i\n",
(double)pl->start, (double)pl->size, (int)pl->lock_type, pl->fd ));
}
/****************************************************************************
Remove any locks on this fd. Called from file_close().
****************************************************************************/
void posix_locking_close_file(files_struct *fsp)
{
struct posix_lock *entries = NULL;
size_t count, i;
/*
* Optimization for the common case where we are the only
* opener of a file. If all fd entries are our own, we don't
* need to explicitly release all the locks via the POSIX functions,
* we can just remove all the entries in the tdb and allow the
* close to remove the real locks.
*/
count = get_posix_lock_entries(fsp, &entries);
if (count == 0) {
DEBUG(10,("posix_locking_close_file: file %s has no outstanding locks.\n", fsp->fsp_name ));
return;
}
for (i = 0; i < count; i++) {
if (entries[i].fd != fsp->fd )
break;
dump_entry(&entries[i]);
}
if (i == count) {
/* All locks are ours. */
DEBUG(10,("posix_locking_close_file: file %s has %u outstanding locks, but all on one fd.\n",
fsp->fsp_name, (unsigned int)count ));
free((char *)entries);
delete_posix_lock_entries(fsp);
return;
}
/*
* Difficult case. We need to delete all our locks, whilst leaving
* all other POSIX locks in place.
*/
for (i = 0; i < count; i++) {
struct posix_lock *pl = &entries[i];
release_posix_lock(fsp, (SMB_BIG_UINT)pl->start, (SMB_BIG_UINT)pl->size );
}
free((char *)entries);
}
/*******************************************************************
Create the in-memory POSIX lock databases.
********************************************************************/
BOOL posix_locking_init(void)
{
if (posix_lock_tdb && posix_pending_close_tdb)
return True;
if (!posix_lock_tdb)
posix_lock_tdb = tdb_open(NULL, 0, TDB_CLEAR_IF_FIRST,
O_RDWR|O_CREAT, 0644);
if (!posix_lock_tdb) {
DEBUG(0,("Failed to open POSIX byte range locking database.\n"));
return False;
}
if (!posix_pending_close_tdb)
posix_pending_close_tdb = tdb_open(NULL, 0, TDB_CLEAR_IF_FIRST,
O_RDWR|O_CREAT, 0644);
if (!posix_pending_close_tdb) {
DEBUG(0,("Failed to open POSIX pending close database.\n"));
return False;
}
return True;
}
/*******************************************************************
Delete the in-memory POSIX lock databases.
********************************************************************/
BOOL posix_locking_end(void)
{
if (posix_lock_tdb && tdb_close(posix_lock_tdb) != 0)
return False;
if (posix_pending_close_tdb && tdb_close(posix_pending_close_tdb) != 0)
return False;
return True;
}
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