xref: /freebsd/sys/sys/disk.h (revision 2be1a816)
1 /*-
2  * ----------------------------------------------------------------------------
3  * "THE BEER-WARE LICENSE" (Revision 42):
4  * <phk@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
5  * can do whatever you want with this stuff. If we meet some day, and you think
6  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
7  * ----------------------------------------------------------------------------
8  *
9  * $FreeBSD$
10  *
11  */
12 
13 #ifndef _SYS_DISK_H_
14 #define	_SYS_DISK_H_
15 
16 #include <sys/ioccom.h>
17 
18 #ifdef _KERNEL
19 
20 #ifndef _SYS_CONF_H_
21 #include <sys/conf.h>	/* XXX: temporary to avoid breakage */
22 #endif
23 
24 void disk_err(struct bio *bp, const char *what, int blkdone, int nl);
25 
26 #endif
27 
28 #define DIOCGSECTORSIZE	_IOR('d', 128, u_int)
29 	/*-
30 	 * Get the sectorsize of the device in bytes.  The sectorsize is the
31 	 * smallest unit of data which can be transfered from this device.
32 	 * Usually this is a power of two but it may not be. (ie: CDROM audio)
33 	 */
34 
35 #define DIOCGMEDIASIZE	_IOR('d', 129, off_t)	/* Get media size in bytes */
36 	/*-
37 	 * Get the size of the entire device in bytes.  This should be a
38 	 * multiple of the sectorsize.
39 	 */
40 
41 #define DIOCGFWSECTORS	_IOR('d', 130, u_int)	/* Get firmware sectorcount */
42 	/*-
43 	 * Get the firmwares notion of number of sectors per track.  This
44 	 * value is mostly used for compatibility with various ill designed
45 	 * disk label formats.  Don't use it unless you have to.
46 	 */
47 
48 #define DIOCGFWHEADS	_IOR('d', 131, u_int)	/* Get firmware headcount */
49 	/*-
50 	 * Get the firmwares notion of number of heads per cylinder.  This
51 	 * value is mostly used for compatibility with various ill designed
52 	 * disk label formats.  Don't use it unless you have to.
53 	 */
54 
55 #define DIOCSKERNELDUMP _IOW('d', 133, u_int)	/* Set/Clear kernel dumps */
56 	/*-
57 	 * Enable/Disable (the argument is boolean) the device for kernel
58 	 * core dumps.
59 	 */
60 
61 #define DIOCGFRONTSTUFF _IOR('d', 134, off_t)
62 	/*-
63 	 * Many disk formats have some amount of space reserved at the
64 	 * start of the disk to hold bootblocks, various disklabels and
65 	 * similar stuff.  This ioctl returns the number of such bytes
66 	 * which may apply to the device.
67 	 */
68 
69 #define	DIOCGFLUSH _IO('d', 135)		/* Flush write cache */
70 	/*-
71 	 * Flush write cache of the device.
72 	 */
73 
74 #define	DIOCGDELETE _IOW('d', 136, off_t[2])	/* Delete data */
75 	/*-
76 	 * Mark data on the device as unused.
77 	 */
78 
79 #define	DISK_IDENT_SIZE	256
80 #define	DIOCGIDENT _IOR('d', 137, char[DISK_IDENT_SIZE])
81 	/*-
82 	 * Get the ident of the given provider. Ident is (most of the time)
83 	 * a uniqe and fixed provider's identifier. Ident's properties are as
84 	 * follow:
85 	 * - ident value is preserved between reboots,
86 	 * - provider can be detached/attached and ident is preserved,
87 	 * - provider's name can change - ident can't,
88 	 * - ident value should not be based on on-disk metadata; in other
89 	 *   words copying whole data from one disk to another should not
90 	 *   yield the same ident for the other disk,
91 	 * - there could be more than one provider with the same ident, but
92 	 *   only if they point at exactly the same physical storage, this is
93 	 *   the case for multipathing for example,
94 	 * - GEOM classes that consumes single providers and provide single
95 	 *   providers, like geli, gbde, should just attach class name to the
96 	 *   ident of the underlying provider,
97 	 * - ident is an ASCII string (is printable),
98 	 * - ident is optional and applications can't relay on its presence.
99 	 */
100 
101 #endif /* _SYS_DISK_H_ */
102