1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3   drbd_limits.h
4   This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
5 */
6 
7 /*
8  * Our current limitations.
9  * Some of them are hard limits,
10  * some of them are arbitrary range limits, that make it easier to provide
11  * feedback about nonsense settings for certain configurable values.
12  */
13 
14 #ifndef DRBD_LIMITS_H
15 #define DRBD_LIMITS_H 1
16 
17 #define DEBUG_RANGE_CHECK 0
18 
19 #define DRBD_MINOR_COUNT_MIN 1U
20 #define DRBD_MINOR_COUNT_MAX 255U
21 #define DRBD_MINOR_COUNT_DEF 32U
22 #define DRBD_MINOR_COUNT_SCALE '1'
23 
24 #define DRBD_VOLUME_MAX 65534U
25 
26 #define DRBD_DIALOG_REFRESH_MIN 0U
27 #define DRBD_DIALOG_REFRESH_MAX 600U
28 #define DRBD_DIALOG_REFRESH_SCALE '1'
29 
30 /* valid port number */
31 #define DRBD_PORT_MIN 1U
32 #define DRBD_PORT_MAX 0xffffU
33 #define DRBD_PORT_SCALE '1'
34 
35 /* startup { */
36   /* if you want more than 3.4 days, disable */
37 #define DRBD_WFC_TIMEOUT_MIN 0U
38 #define DRBD_WFC_TIMEOUT_MAX 300000U
39 #define DRBD_WFC_TIMEOUT_DEF 0U
40 #define DRBD_WFC_TIMEOUT_SCALE '1'
41 
42 #define DRBD_DEGR_WFC_TIMEOUT_MIN 0U
43 #define DRBD_DEGR_WFC_TIMEOUT_MAX 300000U
44 #define DRBD_DEGR_WFC_TIMEOUT_DEF 0U
45 #define DRBD_DEGR_WFC_TIMEOUT_SCALE '1'
46 
47 #define DRBD_OUTDATED_WFC_TIMEOUT_MIN 0U
48 #define DRBD_OUTDATED_WFC_TIMEOUT_MAX 300000U
49 #define DRBD_OUTDATED_WFC_TIMEOUT_DEF 0U
50 #define DRBD_OUTDATED_WFC_TIMEOUT_SCALE '1'
51 /* }*/
52 
53 /* net { */
54   /* timeout, unit centi seconds
55    * more than one minute timeout is not useful */
56 #define DRBD_TIMEOUT_MIN 1U
57 #define DRBD_TIMEOUT_MAX 600U
58 #define DRBD_TIMEOUT_DEF 60U       /* 6 seconds */
59 #define DRBD_TIMEOUT_SCALE '1'
60 
61  /* If backing disk takes longer than disk_timeout, mark the disk as failed */
62 #define DRBD_DISK_TIMEOUT_MIN 0U    /* 0 = disabled */
63 #define DRBD_DISK_TIMEOUT_MAX 6000U /* 10 Minutes */
64 #define DRBD_DISK_TIMEOUT_DEF 0U    /* disabled */
65 #define DRBD_DISK_TIMEOUT_SCALE '1'
66 
67   /* active connection retries when C_WF_CONNECTION */
68 #define DRBD_CONNECT_INT_MIN 1U
69 #define DRBD_CONNECT_INT_MAX 120U
70 #define DRBD_CONNECT_INT_DEF 10U   /* seconds */
71 #define DRBD_CONNECT_INT_SCALE '1'
72 
73   /* keep-alive probes when idle */
74 #define DRBD_PING_INT_MIN 1U
75 #define DRBD_PING_INT_MAX 120U
76 #define DRBD_PING_INT_DEF 10U
77 #define DRBD_PING_INT_SCALE '1'
78 
79  /* timeout for the ping packets.*/
80 #define DRBD_PING_TIMEO_MIN  1U
81 #define DRBD_PING_TIMEO_MAX  300U
82 #define DRBD_PING_TIMEO_DEF  5U
83 #define DRBD_PING_TIMEO_SCALE '1'
84 
85   /* max number of write requests between write barriers */
86 #define DRBD_MAX_EPOCH_SIZE_MIN 1U
87 #define DRBD_MAX_EPOCH_SIZE_MAX 20000U
88 #define DRBD_MAX_EPOCH_SIZE_DEF 2048U
89 #define DRBD_MAX_EPOCH_SIZE_SCALE '1'
90 
91   /* I don't think that a tcp send buffer of more than 10M is useful */
92 #define DRBD_SNDBUF_SIZE_MIN  0U
93 #define DRBD_SNDBUF_SIZE_MAX  (10U<<20)
94 #define DRBD_SNDBUF_SIZE_DEF  0U
95 #define DRBD_SNDBUF_SIZE_SCALE '1'
96 
97 #define DRBD_RCVBUF_SIZE_MIN  0U
98 #define DRBD_RCVBUF_SIZE_MAX  (10U<<20)
99 #define DRBD_RCVBUF_SIZE_DEF  0U
100 #define DRBD_RCVBUF_SIZE_SCALE '1'
101 
102   /* @4k PageSize -> 128kB - 512MB */
103 #define DRBD_MAX_BUFFERS_MIN  32U
104 #define DRBD_MAX_BUFFERS_MAX  131072U
105 #define DRBD_MAX_BUFFERS_DEF  2048U
106 #define DRBD_MAX_BUFFERS_SCALE '1'
107 
108   /* @4k PageSize -> 4kB - 512MB */
109 #define DRBD_UNPLUG_WATERMARK_MIN  1U
110 #define DRBD_UNPLUG_WATERMARK_MAX  131072U
111 #define DRBD_UNPLUG_WATERMARK_DEF (DRBD_MAX_BUFFERS_DEF/16)
112 #define DRBD_UNPLUG_WATERMARK_SCALE '1'
113 
114   /* 0 is disabled.
115    * 200 should be more than enough even for very short timeouts */
116 #define DRBD_KO_COUNT_MIN  0U
117 #define DRBD_KO_COUNT_MAX  200U
118 #define DRBD_KO_COUNT_DEF  7U
119 #define DRBD_KO_COUNT_SCALE '1'
120 /* } */
121 
122 /* syncer { */
123   /* FIXME allow rate to be zero? */
124 #define DRBD_RESYNC_RATE_MIN 1U
125 /* channel bonding 10 GbE, or other hardware */
126 #define DRBD_RESYNC_RATE_MAX (4 << 20)
127 #define DRBD_RESYNC_RATE_DEF 250U
128 #define DRBD_RESYNC_RATE_SCALE 'k'  /* kilobytes */
129 
130 #define DRBD_AL_EXTENTS_MIN  67U
131   /* we use u16 as "slot number", (u16)~0 is "FREE".
132    * If you use >= 292 kB on-disk ring buffer,
133    * this is the maximum you can use: */
134 #define DRBD_AL_EXTENTS_MAX  0xfffeU
135 #define DRBD_AL_EXTENTS_DEF  1237U
136 #define DRBD_AL_EXTENTS_SCALE '1'
137 
138 #define DRBD_MINOR_NUMBER_MIN  -1
139 #define DRBD_MINOR_NUMBER_MAX  ((1 << 20) - 1)
140 #define DRBD_MINOR_NUMBER_DEF  -1
141 #define DRBD_MINOR_NUMBER_SCALE '1'
142 
143 /* } */
144 
145 /* drbdsetup XY resize -d Z
146  * you are free to reduce the device size to nothing, if you want to.
147  * the upper limit with 64bit kernel, enough ram and flexible meta data
148  * is 1 PiB, currently. */
149 /* DRBD_MAX_SECTORS */
150 #define DRBD_DISK_SIZE_MIN  0LLU
151 #define DRBD_DISK_SIZE_MAX  (1LLU * (2LLU << 40))
152 #define DRBD_DISK_SIZE_DEF  0LLU /* = disabled = no user size... */
153 #define DRBD_DISK_SIZE_SCALE 's'  /* sectors */
154 
155 #define DRBD_ON_IO_ERROR_DEF EP_DETACH
156 #define DRBD_FENCING_DEF FP_DONT_CARE
157 #define DRBD_AFTER_SB_0P_DEF ASB_DISCONNECT
158 #define DRBD_AFTER_SB_1P_DEF ASB_DISCONNECT
159 #define DRBD_AFTER_SB_2P_DEF ASB_DISCONNECT
160 #define DRBD_RR_CONFLICT_DEF ASB_DISCONNECT
161 #define DRBD_ON_NO_DATA_DEF OND_IO_ERROR
162 #define DRBD_ON_CONGESTION_DEF OC_BLOCK
163 #define DRBD_READ_BALANCING_DEF RB_PREFER_LOCAL
164 
165 #define DRBD_MAX_BIO_BVECS_MIN 0U
166 #define DRBD_MAX_BIO_BVECS_MAX 128U
167 #define DRBD_MAX_BIO_BVECS_DEF 0U
168 #define DRBD_MAX_BIO_BVECS_SCALE '1'
169 
170 #define DRBD_C_PLAN_AHEAD_MIN  0U
171 #define DRBD_C_PLAN_AHEAD_MAX  300U
172 #define DRBD_C_PLAN_AHEAD_DEF  20U
173 #define DRBD_C_PLAN_AHEAD_SCALE '1'
174 
175 #define DRBD_C_DELAY_TARGET_MIN 1U
176 #define DRBD_C_DELAY_TARGET_MAX 100U
177 #define DRBD_C_DELAY_TARGET_DEF 10U
178 #define DRBD_C_DELAY_TARGET_SCALE '1'
179 
180 #define DRBD_C_FILL_TARGET_MIN 0U
181 #define DRBD_C_FILL_TARGET_MAX (1U<<20) /* 500MByte in sec */
182 #define DRBD_C_FILL_TARGET_DEF 100U /* Try to place 50KiB in socket send buffer during resync */
183 #define DRBD_C_FILL_TARGET_SCALE 's'  /* sectors */
184 
185 #define DRBD_C_MAX_RATE_MIN     250U
186 #define DRBD_C_MAX_RATE_MAX     (4U << 20)
187 #define DRBD_C_MAX_RATE_DEF     102400U
188 #define DRBD_C_MAX_RATE_SCALE	'k'  /* kilobytes */
189 
190 #define DRBD_C_MIN_RATE_MIN     0U
191 #define DRBD_C_MIN_RATE_MAX     (4U << 20)
192 #define DRBD_C_MIN_RATE_DEF     250U
193 #define DRBD_C_MIN_RATE_SCALE	'k'  /* kilobytes */
194 
195 #define DRBD_CONG_FILL_MIN	0U
196 #define DRBD_CONG_FILL_MAX	(10U<<21) /* 10GByte in sectors */
197 #define DRBD_CONG_FILL_DEF	0U
198 #define DRBD_CONG_FILL_SCALE	's'  /* sectors */
199 
200 #define DRBD_CONG_EXTENTS_MIN	DRBD_AL_EXTENTS_MIN
201 #define DRBD_CONG_EXTENTS_MAX	DRBD_AL_EXTENTS_MAX
202 #define DRBD_CONG_EXTENTS_DEF	DRBD_AL_EXTENTS_DEF
203 #define DRBD_CONG_EXTENTS_SCALE DRBD_AL_EXTENTS_SCALE
204 
205 #define DRBD_PROTOCOL_DEF DRBD_PROT_C
206 
207 #define DRBD_DISK_BARRIER_DEF	0U
208 #define DRBD_DISK_FLUSHES_DEF	1U
209 #define DRBD_DISK_DRAIN_DEF	1U
210 #define DRBD_MD_FLUSHES_DEF	1U
211 #define DRBD_TCP_CORK_DEF	1U
212 #define DRBD_AL_UPDATES_DEF     1U
213 
214 /* We used to ignore the discard_zeroes_data setting.
215  * To not change established (and expected) behaviour,
216  * by default assume that, for discard_zeroes_data=0,
217  * we can make that an effective discard_zeroes_data=1,
218  * if we only explicitly zero-out unaligned partial chunks. */
219 #define DRBD_DISCARD_ZEROES_IF_ALIGNED_DEF 1U
220 
221 /* Some backends pretend to support WRITE SAME,
222  * but fail such requests when they are actually submitted.
223  * This is to tell DRBD to not even try. */
224 #define DRBD_DISABLE_WRITE_SAME_DEF 0U
225 
226 #define DRBD_ALLOW_TWO_PRIMARIES_DEF	0U
227 #define DRBD_ALWAYS_ASBP_DEF	0U
228 #define DRBD_USE_RLE_DEF	1U
229 #define DRBD_CSUMS_AFTER_CRASH_ONLY_DEF 0U
230 
231 #define DRBD_AL_STRIPES_MIN     1U
232 #define DRBD_AL_STRIPES_MAX     1024U
233 #define DRBD_AL_STRIPES_DEF     1U
234 #define DRBD_AL_STRIPES_SCALE   '1'
235 
236 #define DRBD_AL_STRIPE_SIZE_MIN   4U
237 #define DRBD_AL_STRIPE_SIZE_MAX   16777216U
238 #define DRBD_AL_STRIPE_SIZE_DEF   32U
239 #define DRBD_AL_STRIPE_SIZE_SCALE 'k' /* kilobytes */
240 
241 #define DRBD_SOCKET_CHECK_TIMEO_MIN 0U
242 #define DRBD_SOCKET_CHECK_TIMEO_MAX DRBD_PING_TIMEO_MAX
243 #define DRBD_SOCKET_CHECK_TIMEO_DEF 0U
244 #define DRBD_SOCKET_CHECK_TIMEO_SCALE '1'
245 
246 #define DRBD_RS_DISCARD_GRANULARITY_MIN 0U
247 #define DRBD_RS_DISCARD_GRANULARITY_MAX (1U<<20)  /* 1MiByte */
248 #define DRBD_RS_DISCARD_GRANULARITY_DEF 0U     /* disabled by default */
249 #define DRBD_RS_DISCARD_GRANULARITY_SCALE '1' /* bytes */
250 
251 #endif
252