diff options
Diffstat (limited to 'source/lib/util_file.c')
| -rw-r--r-- | source/lib/util_file.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/source/lib/util_file.c b/source/lib/util_file.c index f4325b813bb..44b37466c71 100644 --- a/source/lib/util_file.c +++ b/source/lib/util_file.c @@ -108,6 +108,117 @@ BOOL file_unlock(int fd, int *plock_depth) return ret; } +/**************************************************************************** +routine to do file locking +****************************************************************************/ +BOOL fcntl_lock(int fd, int op, SMB_OFF_T offset, SMB_OFF_T count, int type) +{ +#if HAVE_FCNTL_LOCK + SMB_STRUCT_FLOCK lock; + int ret; + + if(lp_ole_locking_compat()) { + SMB_OFF_T mask2= ((SMB_OFF_T)0x3) << (SMB_OFF_T_BITS-4); + SMB_OFF_T mask = (mask2<<2); + + /* make sure the count is reasonable, we might kill the lockd otherwise */ + count &= ~mask; + + /* the offset is often strange - remove 2 of its bits if either of + the top two bits are set. Shift the top ones by two bits. This + still allows OLE2 apps to operate, but should stop lockd from + dieing */ + if ((offset & mask) != 0) + offset = (offset & ~mask) | (((offset & mask) >> 2) & mask2); + } else { + 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; + + /* interpret negative counts as large numbers */ + if (count < 0) + count &= ~mask; + + /* no negative offsets */ + if(offset < 0) + offset &= ~mask; + + /* count + offset must be in range */ + while ((offset < 0 || (offset + count < 0)) && mask) + { + offset &= ~mask; + mask = ((mask >> 1) & neg_mask); + } + } + + DEBUG(8,("fcntl_lock %d %d %.0f %.0f %d\n",fd,op,(double)offset,(double)count,type)); + + lock.l_type = type; + lock.l_whence = SEEK_SET; + lock.l_start = offset; + lock.l_len = count; + lock.l_pid = 0; + + errno = 0; + + ret = fcntl(fd,op,&lock); + if (errno == EFBIG) + { + if( DEBUGLVL( 0 )) + { + dbgtext("fcntl_lock: WARNING: lock request at offset %.0f, length %.0f returned\n", (double)offset,(double)count); + dbgtext("a 'file too large' error. This can happen when using 64 bit lock offsets\n"); + dbgtext("on 32 bit NFS mounted file systems. Retrying with 32 bit truncated length.\n"); + } + /* 32 bit NFS file system, retry with smaller offset */ + errno = 0; + lock.l_len = count & 0xffffffff; + ret = fcntl(fd,op,&lock); + } + + if (errno != 0) + DEBUG(3,("fcntl lock gave errno %d (%s)\n",errno,strerror(errno))); + + /* a lock query */ + if (op == SMB_F_GETLK) + { + if ((ret != -1) && + (lock.l_type != F_UNLCK) && + (lock.l_pid != 0) && + (lock.l_pid != getpid())) + { + DEBUG(3,("fd %d is locked by pid %d\n",fd,(int)lock.l_pid)); + return(True); + } + + /* it must be not locked or locked by me */ + return(False); + } + + /* a lock set or unset */ + if (ret == -1) + { + DEBUG(3,("lock failed at offset %.0f count %.0f op %d type %d (%s)\n", + (double)offset,(double)count,op,type,strerror(errno))); + + /* perhaps it doesn't support this sort of locking?? */ + if (errno == EINVAL) + { + DEBUG(3,("locking not supported? returning True\n")); + return(True); + } + + return(False); + } + + /* everything went OK */ + DEBUG(8,("Lock call successful\n")); + + return(True); +#else + return(False); +#endif +} /*************************************************************** locks a file for enumeration / modification. update to be set = True if modification is required. @@ -365,3 +476,4 @@ void *open_file_if_modified(const char *filename, char *mode, time_t *lastmodifi return (void *)f; } + |