1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* |
3 | The compile-time configurable defaults for the Linux SCSI tape driver. |
4 | |
5 | Copyright 1995-2003 Kai Makisara. |
6 | |
7 | Last modified: Thu Feb 21 21:47:07 2008 by kai.makisara |
8 | */ |
9 | |
10 | #ifndef _ST_OPTIONS_H |
11 | #define _ST_OPTIONS_H |
12 | |
13 | /* If TRY_DIRECT_IO is non-zero, the driver tries to transfer data directly |
14 | between the user buffer and tape drive. If this is not possible, driver |
15 | buffer is used. If TRY_DIRECT_IO is zero, driver buffer is always used. */ |
16 | #define TRY_DIRECT_IO 1 |
17 | |
18 | /* The driver does not wait for some operations to finish before returning |
19 | to the user program if ST_NOWAIT is non-zero. This helps if the SCSI |
20 | adapter does not support multiple outstanding commands. However, the user |
21 | should not give a new tape command before the previous one has finished. */ |
22 | #define ST_NOWAIT 0 |
23 | |
24 | /* If ST_IN_FILE_POS is nonzero, the driver positions the tape after the |
25 | record been read by the user program even if the tape has moved further |
26 | because of buffered reads. Should be set to zero to support also drives |
27 | that can't space backwards over records. NOTE: The tape will be |
28 | spaced backwards over an "accidentally" crossed filemark in any case. */ |
29 | #define ST_IN_FILE_POS 0 |
30 | |
31 | /* If ST_RECOVERED_WRITE_FATAL is non-zero, recovered errors while writing |
32 | are considered "hard errors". */ |
33 | #define ST_RECOVERED_WRITE_FATAL 0 |
34 | |
35 | /* The "guess" for the block size for devices that don't support MODE |
36 | SENSE. */ |
37 | #define ST_DEFAULT_BLOCK 0 |
38 | |
39 | /* The minimum tape driver buffer size in kilobytes in fixed block mode. |
40 | Must be non-zero. */ |
41 | #define ST_FIXED_BUFFER_BLOCKS 32 |
42 | |
43 | /* Maximum number of scatter/gather segments */ |
44 | #define ST_MAX_SG 256 |
45 | |
46 | /* The number of scatter/gather segments to allocate at first try (must be |
47 | smaller or equal to the maximum). */ |
48 | #define ST_FIRST_SG 8 |
49 | |
50 | /* The size of the first scatter/gather segments (determines the maximum block |
51 | size for SCSI adapters not supporting scatter/gather). The default is set |
52 | to try to allocate the buffer as one chunk. */ |
53 | #define ST_FIRST_ORDER 5 |
54 | |
55 | |
56 | /* The following lines define defaults for properties that can be set |
57 | separately for each drive using the MTSTOPTIONS ioctl. */ |
58 | |
59 | /* If ST_TWO_FM is non-zero, the driver writes two filemarks after a |
60 | file being written. Some drives can't handle two filemarks at the |
61 | end of data. */ |
62 | #define ST_TWO_FM 0 |
63 | |
64 | /* If ST_BUFFER_WRITES is non-zero, writes in fixed block mode are |
65 | buffered until the driver buffer is full or asynchronous write is |
66 | triggered. May make detection of End-Of-Medium early enough fail. */ |
67 | #define ST_BUFFER_WRITES 1 |
68 | |
69 | /* If ST_ASYNC_WRITES is non-zero, the SCSI write command may be started |
70 | without waiting for it to finish. May cause problems in multiple |
71 | tape backups. */ |
72 | #define ST_ASYNC_WRITES 1 |
73 | |
74 | /* If ST_READ_AHEAD is non-zero, blocks are read ahead in fixed block |
75 | mode. */ |
76 | #define ST_READ_AHEAD 1 |
77 | |
78 | /* If ST_AUTO_LOCK is non-zero, the drive door is locked at the first |
79 | read or write command after the device is opened. The door is opened |
80 | when the device is closed. */ |
81 | #define ST_AUTO_LOCK 0 |
82 | |
83 | /* If ST_FAST_MTEOM is non-zero, the MTEOM ioctl is done using the |
84 | direct SCSI command. The file number status is lost but this method |
85 | is fast with some drives. Otherwise MTEOM is done by spacing over |
86 | files and the file number status is retained. */ |
87 | #define ST_FAST_MTEOM 0 |
88 | |
89 | /* If ST_SCSI2LOGICAL is nonzero, the logical block addresses are used for |
90 | MTIOCPOS and MTSEEK by default. Vendor addresses are used if ST_SCSI2LOGICAL |
91 | is zero. */ |
92 | #define ST_SCSI2LOGICAL 0 |
93 | |
94 | /* If ST_SYSV is non-zero, the tape behaves according to the SYS V semantics. |
95 | The default is BSD semantics. */ |
96 | #define ST_SYSV 0 |
97 | |
98 | /* If ST_SILI is non-zero, the SILI bit is set when reading in variable block |
99 | mode and the block size is determined using the residual returned by the HBA. */ |
100 | #define ST_SILI 0 |
101 | |
102 | /* Time to wait for the drive to become ready if blocking open */ |
103 | #define ST_BLOCK_SECONDS 120 |
104 | |
105 | #endif |
106 | |