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| -rw-r--r-- | source3/locking/posix.c | 1208 |
1 files changed, 1208 insertions, 0 deletions
diff --git a/source3/locking/posix.c b/source3/locking/posix.c new file mode 100644 index 0000000000..f05a0a2a31 --- /dev/null +++ b/source3/locking/posix.c @@ -0,0 +1,1208 @@ +/* + 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 ints + * 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.dev = 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) +{ + struct posix_lock_key = locking_key_fsp(fsp); + TDB_DATA kbuf, dbuf; + size_t count = 0; + int *fd_array = NULL; + + dbuf.dptr = NULL; + + tdb_lockchain(posix_pending_close_tdb, kbuf); + 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")); + tdb_unlockchain(posix_pending_close_tdb, kbuf); + 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); + tdb_unlockchain(posix_pending_close_tdb, kbuf); + return True; +} + +/**************************************************************************** + Remove all fd entries for a specific dev/inode pair from the tdb. +****************************************************************************/ + +static void delete_close_entries(files_struct *fsp) +{ + struct posix_lock_key = locking_key_fsp(fsp); + TDB_DATA kbuf, dbuf; + + tdb_lockchain(posix_pending_close_tdb, kbuf); + if (tdb_delete(posix_pending_close_tdb, kbuf) == -1) + DEBUG(0,("delete_close_entries: tdb_delete fail !\n")); + tdb_unlockchain(posix_pending_close_tdb, kbuf); +} + +/**************************************************************************** + 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) +{ + struct posix_lock_key = locking_key_fsp(fsp); + TDB_DATA kbuf, dbuf; + size_t count = 0; + + *entries = NULL; + dbuf.dptr = NULL; + + tdb_lockchain(posix_pending_close_tdb, kbuf); + dbuf = tdb_fetch(posix_pending_close_tdb, kbuf); + + if (!dbuf.dptr) { + tdb_unlockchain(posix_pending_close_tdb, kbuf); + return 0; + } + + *entries = (int *)dbuf.dptr; + count = (size_t)(dbuf.dsize / sizeof(int)); + + tdb_unlockchain(posix_pending_close_tdb, kbuf); + + 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) +{ + struct posix_lock_key = locking_key_fsp(fsp); + TDB_DATA kbuf, dbuf; + size_t count = 0; + + *entries = NULL; + + dbuf.dptr = NULL; + + tdb_lockchain(posix_lock_tdb, kbuf); + dbuf = tdb_fetch(posix_lock_tdb, kbuf); + + if (!dbuf.dptr) { + tdb_unlockchain(posix_lock_tdb, kbuf); + return 0; + } + + *entries = (struct posix_lock_struct *)dbuf.dptr; + count = (size_t)(dbuf.dsize / sizeof(struct posix_lock_struct)); + + tdb_unlockchain(posix_lock_tdb, kbuf); + + 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) +{ + struct posix_lock_key = locking_key_fsp(fsp); + TDB_DATA kbuf, 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; + + tdb_lockchain(posix_lock_tdb, kbuf); + 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, rec, 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); + tdb_unlockchain(posix_lock_tdb, kbuf); + + 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); + tdb_unlockchain(tdb, kbuf); + 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) +{ + struct posix_lock_key = locking_key_fsp(fsp); + TDB_DATA kbuf, dbuf; + struct posix_lock *locks; + size_t i, count; + + dbuf.dptr = NULL; + + tdb_lockchain(posix_lock_tdb, kbuf); + 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 lock_struct *)dbuf.dptr; + count = (size_t(dbuf.dsize / sizeof(*locks)); + + for (i=0; i<count; i++) { + struct posix_lock *pl = &locks[i]; + + if (pl->fd == 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(tdb, kbuf, dbuf, TDB_REPLACE); + } + + free(dbuf.dptr); + tdb_unlockchain(tdb, kbuf); + return True; + } + } + + /* We didn't find it. */ + + fail: + if (dbuf.dptr) + free(dbuf.dptr); + tdb_unlockchain(tdb, kbuf); + 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, 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, 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 read locks on different + * file descriptors will not be held separately by the kernel (POSIX + * braindamage), but will be merged into one continuous read 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; + int fd; +}; + +/**************************************************************************** + 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) +{ + struct lock_key key; + TDB_DATA kbuf, dbuf; + struct lock_struct *locks; + int num_locks, i; + + /* + * Setup the key for this fetch. + */ + key.device = dev; + key.inode = ino; + kbuf.dptr = (char *)&key; + kbuf.dsize = sizeof(key); + + dbuf.dptr = NULL; + + tdb_lockchain(tdb, kbuf); + dbuf = tdb_fetch(tdb, kbuf); + + if (!dbuf.dptr) { + tdb_unlockchain(tdb, kbuf); + return ulhead; + } + + locks = (struct lock_struct *)dbuf.dptr; + num_locks = dbuf.dsize / sizeof(*locks); + + /* + * Check the current lock list on this dev/inode pair. + * Quit if the list is deleted. + */ + + DEBUG(10,("brl_unlock_list: curr: start=%.0f,size=%.0f\n", + (double)ulhead->start, (double)ulhead->size )); + + for (i=0; i<num_locks && ulhead; i++) { + + struct lock_struct *lock = &locks[i]; + struct unlock_list *ul_curr; + + /* If it's not this process, ignore it. */ + if (lock->context.pid != pid) + continue; + + /* + * 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,("brl_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,("brl_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; + ul_new->smbpid = ul_curr->smbpid; + + /* 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++) */ + + tdb_unlockchain(tdb, kbuf); + + if (dbuf.dptr) + free(dbuf.dptr); + + return ulhead; +} + +/**************************************************************************** + POSIX function to release a lock given a list. Returns True if the + lock could be released, False if not. +****************************************************************************/ + +static 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)offset, (double)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; + + 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; + ul->fd = fsp->fd; + + DLIST_ADD(ulist, ul); + + /* + * The following call calculates if there are any + * overlapping read locks held by this process on + * other fd's open on the same file and creates a + * list of unlock ranges that will allow other + * 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) { + SMB_OFF_T offset = ulist->start; + SMB_OFF_T count = ulist->size; + + DEBUG(5,("release_posix_lock: Real unlock: offset = %.0f, count = %.0f\n", + (double)offset, (double)count )); + + if(u_count == 0) { + + /* + * This lock must overlap with an existing read-only lock + * held by another fd. Don't do any POSIX call. + */ + + continue; + } + + /* + * If the requested lock won't fit in the POSIX range, we will + * pretend it was successful. + */ + + if(!posix_lock_in_range(&offset, &count, offset, count)) + continue; + + DEBUG(5,("release_posix_lock: Real unlock: offset = %.0f, count = %.0f\n", + (double)offset, (double)count )); + + ret = fcntl_lock(fsp->fd,SMB_F_SETLK,offset,count,F_UNLCK); + } + + talloc_destroy(ul_ctx); + + /* + * 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-> + + return ret; +} + +/**************************************************************************** + Return a lock list associated with an open file. +****************************************************************************/ + +struct unlock_list *brl_getlocklist( TALLOC_CTX *ctx, SMB_DEV_T dev, SMB_INO_T ino, pid_t pid, int tid, int fnum) +{ + struct lock_key key; + TDB_DATA kbuf, dbuf; + int i, count; + struct lock_struct *locks; + struct unlock_list *ulist = NULL; + + key.device = dev; + key.inode = ino; + kbuf.dptr = (char *)&key; + kbuf.dsize = sizeof(key); + + dbuf.dptr = NULL; + + tdb_lockchain(tdb, kbuf); + dbuf = tdb_fetch(tdb, kbuf); + + if (!dbuf.dptr) { + tdb_unlockchain(tdb, kbuf); + return NULL; + } + + /* There are existing locks - allocate an entry for each one. */ + 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 == tid && + lock->context.pid == pid && + lock->fnum == fnum) { + + struct unlock_list *ul_new = (struct unlock_list *)talloc(ctx, + sizeof(struct unlock_list)); + + if(ul_new == NULL) { + DEBUG(0,("brl_getlocklist: talloc fail.\n")); + return NULL; /* The talloc_destroy takes care of cleanup. */ + } + + ZERO_STRUCTP(ul_new); + ul_new->start = lock->start; + ul_new->size = lock->size; + ul_new->smbpid = lock->context.smbpid; + + DLIST_ADD(ulist, ul_new); + } + } + + if (dbuf.dptr) + free(dbuf.dptr); + tdb_unlockchain(tdb, kbuf); + + return ulist; +} + +/**************************************************************************** + Remove any locks on this fd. Called from file_close(). +****************************************************************************/ + +void posix_locking_close_file(files_struct *fsp) +{ + TALLOC_CTX *ul_ctx = NULL; + struct unlock_list *ul = NULL; + int eclass; + uint32 ecode; + struct pending_closes *pc; + + /* + * 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 release all the brl locks, as in the no POSIX locking case. + */ + + if ((pc = find_pending_close_entry(fsp->dev, fsp->inode)) != NULL) { + + if (pc->fd_array_size == 1 && pc->fd_array[0] == fsp->fd ) { + /* + * Just release all the brl locks, no need to release individually. + */ + + brl_close(fsp->dev, fsp->inode, pid, fsp->conn->cnum, fsp->fnum); + return; + } + } + + if ((ul_ctx = talloc_init()) == NULL) { + DEBUG(0,("locking_close_file: unable to init talloc context.\n")); + return; + } + + /* + * We need to release all POSIX locks we have on this + * fd. Get all our existing locks from the tdb locking database. + */ + + ul = brl_getlocklist(ul_ctx, fsp->dev, fsp->inode, pid, fsp->conn->cnum, fsp->fnum); + + /* + * Now unlock all of them. This will remove the brl entry also + * for each lock. Note we need to make sure the global_smbpid matches + * the one associated with each lock in case the client plays games + * with smbpids (like smbtorture does :-). + */ + + for(; ul; ul = ul->next) { + global_smbpid = ul->smbpid; + do_unlock(fsp,fsp->conn,ul->size,ul->start,&eclass,&ecode); + } + + talloc_destroy(ul_ctx); + + } else { + + /* + * Just release all the brl locks, no need to release individually. + */ + + brl_close(fsp->dev, fsp->inode, pid, fsp->conn->cnum, fsp->fnum); + } +} + +/******************************************************************* + Create the in-memory POSIX lock databases. +********************************************************************/ + +void posix_lock_init(void) +{ + if (posix_lock_tdb && posix_pending_close_tdb) + return; + + 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")); + } + 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")); + } +} |