diff options
Diffstat (limited to 'source3/locking/locking.c')
| -rw-r--r-- | source3/locking/locking.c | 184 |
1 files changed, 179 insertions, 5 deletions
diff --git a/source3/locking/locking.c b/source3/locking/locking.c index b61e8acedc..9d407bf16b 100644 --- a/source3/locking/locking.c +++ b/source3/locking/locking.c @@ -2,7 +2,8 @@ Unix SMB/Netbios implementation. Version 3.0 Locking functions - Copyright (C) Andrew Tridgell 1992-1999 + Copyright (C) Andrew Tridgell 1992-2000 + 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 @@ -30,6 +31,8 @@ support. rewrtten completely to use new tdb code. Tridge, Dec '99 + + Added POSIX locking support. Jeremy Allison (jeremy@valinux.com), Apr. 2000. */ #include "includes.h" @@ -40,6 +43,179 @@ static TDB_CONTEXT *tdb; int global_smbpid; +/* + * Doubly linked list to hold pending closes needed for + * POSIX locks. This may be changed to use a hash table (as + * in lib/hash.c if this is too slow in use.... JRA. + */ + +struct pending_closes { + struct pending_closes *next; + struct pending_closes *prev; + SMB_DEV_T dev; + SMB_INO_T inode; + int num_posix_locks; + size_t fd_array_size; + int *fd_array; +}; + +static struct pending_closes *pending_close_list = NULL; + +/**************************************************************************** + Find a dev/inode pair in the pending close list. +****************************************************************************/ + +static struct pending_closes *find_pending_close_entry(SMB_DEV_T dev, SMB_INO_T inode) +{ + struct pending_closes *pc; + + for(pc = pending_close_list; pc; pc = pc->next) { + if (dev == pc->dev && inode == pc->inode) { + DLIST_PROMOTE(pending_close_list,pc); + return pc; + } + } + + return NULL; +} + +/**************************************************************************** + Add an fd into the pending close array. +****************************************************************************/ + +static BOOL add_fd_to_close_entry(struct pending_closes *pc, int fd) +{ + if ((pc->fd_array = (int *)Realloc(pc->fd_array, (pc->fd_array_size + 1)*sizeof(int))) == NULL) { + DEBUG(0,("add_fd_to_close_entry: Unable to increase fd_array !\n")); + return False; + } + + pc->fd_array[pc->fd_array_size] = fd; + pc->fd_array_size++; + + DEBUG(10,("add_fd_to_close_entry: added fd = %d, size = %u : dev = %.0f, ino = %.0f\n", + fd, (unsigned int)pc->fd_array_size, (double)pc->dev, (double)pc->inode )); + + return True; +} + +/**************************************************************************** + Deal with pending closes needed by POSIX locking support. +****************************************************************************/ + +BOOL fd_close_posix_locks(struct connection_struct *conn, files_struct *fsp) +{ + struct pending_closes *pc; + int saved_errno = 0; + size_t i; + + if (!lp_posix_locking(SNUM(conn))) + return True; + + pc = find_pending_close_entry(fsp->dev, fsp->inode); + + if (!pc) { + /* + * No other open with a POSIX lock on this dev/inode within this smbd. + * Just exit. + */ + return True; + } + + if (pc->num_posix_locks) { + /* + * There are outstanding locks on this dev/inode pair. + * Add our fd to the list and set fsp->fd to -1 to + * stop the close. + */ + + if (!add_fd_to_close_entry(pc, fsp->fd)) + return False; + + fsp->fd = -1; + return True; + } + + DEBUG(10,("fd_close_posix_locks: doing close on %u fd's.\n", (unsigned int)pc->fd_array_size )); + + /* + * This is the last close. If there are pending fd's close them + * now. Save the errno just in case. + */ + + for(i = 0; i < pc->fd_array_size; i++) { + if (pc->fd_array[i] != -1) { + if (conn->vfs_ops.close(pc->fd_array[i]) == -1) { + saved_errno = errno; + } + } + } + + if (pc->fd_array) + free((char *)pc->fd_array); + + DLIST_REMOVE(pending_close_list, pc); + + free((char *)pc); + + if (saved_errno != 0) { + errno = saved_errno; + } + + return True; +} + +/**************************************************************************** + A POSIX lock was granted. Increment the lock list count (create if needed). +****************************************************************************/ + +static void increment_posix_lock_list(files_struct *fsp) +{ + struct pending_closes *pc; + + if ((pc = find_pending_close_entry(fsp->dev, fsp->inode)) == NULL) { + if (!(pc = (struct pending_closes *)malloc(sizeof(struct pending_closes)))) { + DEBUG(0,("increment_lock_list: malloc fail.\n")); + return; + } + ZERO_STRUCTP(pc); + pc->dev = fsp->dev; + pc->inode = fsp->inode; + DLIST_ADD(pending_close_list, pc); + + DEBUG(10,("increment_posix_lock_list: creating entry for file %s: dev = %.0f, ino = %.0f\n", + fsp->fsp_name, (double)fsp->dev, (double)fsp->inode )); + } + + pc->num_posix_locks++; + + DEBUG(10,("increment_posix_lock_list: entry for file %s: dev = %.0f, ino = %.0f, num_locks = %d\n", + fsp->fsp_name, (double)pc->dev, (double)pc->inode, pc->num_posix_locks )); +} + + +/**************************************************************************** + A POSIX lock was granted. Decrement the lock list count. +****************************************************************************/ + +static void decrement_posix_lock_list(files_struct *fsp) +{ + struct pending_closes *pc; + + pc = find_pending_close_entry(fsp->dev, fsp->inode); + + if (pc == NULL) { + smb_panic("decrement_lock_list: Unlock not found !\n"); + } + + pc->num_posix_locks--; + + DEBUG(10,("decrement_posix_lock_list: entry for file %s: dev = %.0f, ino = %.0f, num_locks = %d\n", + fsp->fsp_name, (double)pc->dev, (double)pc->inode, pc->num_posix_locks )); + + SMB_ASSERT(pc->num_posix_locks >= 0); +} + /**************************************************************************** Debugging aid :-). ****************************************************************************/ @@ -444,7 +620,7 @@ BOOL do_lock(files_struct *fsp,connection_struct *conn, */ if((ok = set_posix_lock(fsp, offset, count, lock_type)) == True) - fsp->num_posix_locks++; + increment_posix_lock_list(fsp); else { /* * We failed to map - we must now remove the brl @@ -558,9 +734,7 @@ BOOL do_unlock(files_struct *fsp,connection_struct *conn, * if it may have been split into multiple smaller POSIX unlock ranges. */ - fsp->num_posix_locks--; - - SMB_ASSERT(fsp->num_posix_locks >= 0); + decrement_posix_lock_list(fsp); return True; /* Did unlock */ } |