"Fossies" - the Fresh Open Source Software Archive

Member "xorriso-1.5.4/libburn/ddlpa.h" (30 Jan 2021, 3972 Bytes) of package /linux/misc/xorriso-1.5.4.pl02.tar.gz:

    1 
    2 /* ddlpa
    3    Implementation of Delicate Device Locking Protocol level A.
    4    Copyright (C) 2007 Thomas Schmitt <scdbackup@gmx.net>
    5    Provided under any of the following licenses: GPL, LGPL, BSD. Choose one.
    6 
    7    See ../doc/ddlp.txt for a description of the protocol.
    8 */
    9 
   10 #ifndef DDLPA_H_INCLUDED
   11 #define DDLPA_H_INCLUDED 1
   12 
   13 
   14 /* An upper limit for the length of standard paths and sibling paths */
   15 #define DDLPA_MAX_STD_LEN 15
   16 
   17 /* An upper limit for the number of siblings */
   18 #define DDLPA_MAX_SIBLINGS 5
   19 
   20 struct ddlpa_lock {
   21 
   22     /* Recorded input parameters of locking call */
   23     char *path;
   24     int  path_is_valid;
   25     int  in_bus, in_target, in_lun;
   26     int  inbtl_is_valid;
   27     int  ddlpa_flags;
   28     int  o_flags;
   29 
   30     /* Result of locking call */
   31     char std_path[DDLPA_MAX_STD_LEN + 1];
   32     int  fd;
   33     dev_t rdev;
   34     dev_t dev;
   35     ino_t ino;
   36     int  host, channel, id, lun, bus;
   37     int  hcilb_is_valid;
   38     int  num_siblings;
   39     char sibling_paths[DDLPA_MAX_SIBLINGS][DDLPA_MAX_STD_LEN + 1];
   40     int  sibling_fds[DDLPA_MAX_SIBLINGS];
   41     dev_t sibling_rdevs[DDLPA_MAX_SIBLINGS];
   42     dev_t sibling_devs[DDLPA_MAX_SIBLINGS];
   43     ino_t sibling_inodes[DDLPA_MAX_SIBLINGS];
   44 
   45     /* Is NULL if all goes well. Else it may contain a text message. */
   46     char *errmsg;
   47 };
   48 
   49 
   50 
   51 /** Lock a recorder by naming a device file path. Allocate a new container.
   52     @param path        Gives the file system path of the recorder
   53                        as known to the calling program.
   54     @param o_flags     flags for open(2). Do not use O_EXCL here because this
   55                        is done automatically whenever appropriate.
   56                        Advised is O_RDWR | O_LARGEFILE, eventually | O_NDELAY.
   57     @param ddlpa_flags 0 = default behavior: the standard path will be opened
   58                            and treated by fcntl(F_SETLK)
   59                        DDLPA_OPEN_GIVEN_PATH causes the input parameter "path"
   60                        to be used with open(2) and fcntl(2).
   61                        DDLPA_ALLOW_MISSING_SGRCD allows to grant a lock
   62                        although not all three, a sg, a sr and a scd device
   63                        file have been found during sibling search. Normally
   64                        this is counted as failure due to EBUSY. 
   65     @param lockbundle  gets allocated and then represents the locking state
   66     @param errmsg      if *errmsg is not NULL after the call, it contains an
   67                        error message. Then to be released by free(3).
   68                        It is NULL in case of success or lack of memory.
   69     @return            0=success , else an errno compatible error number
   70 */
   71 int ddlpa_lock_path(char *path, int  o_flags, int ddlpa_flags, 
   72                     struct ddlpa_lock **lockbundle, char **errmsg);
   73 
   74 
   75 /** Lock a recorder by naming a Bus,Target,Lun number triple.
   76     Allocate a new container.
   77     @param bus         parameter to match ioctl(SCSI_IOCTL_GET_BUS_NUMBER)
   78     @param target      parameter to match ioctl(SCSI_IOCTL_GET_IDLUN) &0xff
   79     @param lun         parameter to match ioctl(SCSI_IOCTL_GET_IDLUN) &0xff00
   80     @param o_flags     see ddlpa_lock_path().
   81     @param ddlpa_flags see ddlpa_lock_path(). Flag DDLPA_OPEN_GIVEN_PATH
   82                        will be ignored.
   83     @param lockbundle  see ddlpa_lock_path().
   84     @param errmsg      see ddlpa_lock_path().
   85     @return            0=success , else an errno compatible error number
   86 */
   87 int ddlpa_lock_btl(int bus, int target, int lun,
   88                    int  o_flags, int ddlpa_flags,
   89                    struct ddlpa_lock **lockbundle, char **errmsg);
   90 
   91 
   92 /** Release the lock by closing all filedescriptors and freeing memory.
   93     @param lockbundle  the lock which is to be released. 
   94                        *lockbundle will be set to NULL by this call.
   95     @return            0=success , 1=failure
   96 */
   97 int ddlpa_destroy(struct ddlpa_lock **lockbundle);
   98 
   99 
  100 
  101 /** Definitions of macros used in above functions */
  102 
  103 #define DDLPA_OPEN_GIVEN_PATH 1
  104 #define DDLPA_ALLOW_MISSING_SGRCD 2
  105 
  106 
  107 #endif /* DDLPA_H_INCLUDED */