xref: /freebsd/sys/kern/subr_disk.c (revision c807777a43ef2b59786fa8a1a35c1f154fd069e5)
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 #include <sys/param.h>
14 #include <sys/systm.h>
15 #include <sys/kernel.h>
16 #include <sys/sysctl.h>
17 #include <sys/buf.h>
18 #include <sys/conf.h>
19 #include <sys/disk.h>
20 #include <sys/malloc.h>
21 #include <machine/md_var.h>
22 
23 MALLOC_DEFINE(M_DISK, "disk", "disk data");
24 
25 static d_strategy_t diskstrategy;
26 static d_open_t diskopen;
27 static d_close_t diskclose;
28 static d_ioctl_t diskioctl;
29 static d_psize_t diskpsize;
30 
31 dev_t
32 disk_create(int unit, struct disk *dp, int flags, struct cdevsw *cdevsw, struct cdevsw *proto)
33 {
34 	dev_t dev;
35 
36 	bzero(dp, sizeof(*dp));
37 
38 	dev = makedev(cdevsw->d_maj, 0);
39 	if (!devsw(dev)) {
40 		*proto = *cdevsw;
41 		proto->d_open = diskopen;
42 		proto->d_close = diskclose;
43 		proto->d_ioctl = diskioctl;
44 		proto->d_strategy = diskstrategy;
45 		proto->d_psize = diskpsize;
46 		cdevsw_add(proto);
47 	}
48 
49 	if (bootverbose)
50 		printf("Creating DISK %s%d\n", cdevsw->d_name, unit);
51 	dev = make_dev(proto, dkmakeminor(unit, WHOLE_DISK_SLICE, RAW_PART),
52 	    0, 0, 0, "r%s%d", cdevsw->d_name, unit);
53 
54 	dev->si_disk = dp;
55 	dp->d_dev = dev;
56 	dp->d_dsflags = flags;
57 	dp->d_devsw = cdevsw;
58 	return (dev);
59 }
60 
61 int
62 disk_dumpcheck(dev_t dev, u_int *count, u_int *blkno, u_int *secsize)
63 {
64 	struct disk *dp;
65 	struct disklabel *dl;
66 	u_int boff;
67 
68 	dp = dev->si_disk;
69 	if (!dp)
70 		return (ENXIO);
71 	if (!dp->d_slice)
72 		return (ENXIO);
73 	dl = dsgetlabel(dev, dp->d_slice);
74 	if (!dl)
75 		return (ENXIO);
76 	*count = (u_long)Maxmem * PAGE_SIZE / dl->d_secsize;
77 	if (dumplo < 0 ||
78 	    (dumplo + *count > dl->d_partitions[dkpart(dev)].p_size))
79 		return (EINVAL);
80 	boff = dl->d_partitions[dkpart(dev)].p_offset +
81 	    dp->d_slice->dss_slices[dkslice(dev)].ds_offset;
82 	*blkno = boff + dumplo;
83 	*secsize = dl->d_secsize;
84 	return (0);
85 
86 }
87 
88 void
89 disk_invalidate (struct disk *disk)
90 {
91 	dsgone(&disk->d_slice);
92 }
93 
94 void
95 disk_delete(dev_t dev)
96 {
97 	return;
98 }
99 
100 /*
101  * The cdevsw functions
102  */
103 
104 static int
105 diskopen(dev_t dev, int oflags, int devtype, struct proc *p)
106 {
107 	dev_t pdev;
108 	struct disk *dp;
109 	int error;
110 
111 	error = 0;
112 	pdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
113 
114 	dp = pdev->si_disk;
115 	if (!dp)
116 		return (ENXIO);
117 
118 	while (dp->d_flags & DISKFLAG_LOCK) {
119 		dp->d_flags |= DISKFLAG_WANTED;
120 		error = tsleep(dp, PRIBIO | PCATCH, "diskopen", hz);
121 		if (error)
122 			return (error);
123 	}
124 	dp->d_flags |= DISKFLAG_LOCK;
125 
126 	if (!dsisopen(dp->d_slice)) {
127 		if (!pdev->si_iosize_max)
128 			pdev->si_iosize_max = dev->si_iosize_max;
129 		error = dp->d_devsw->d_open(pdev, oflags, devtype, p);
130 	}
131 
132 	/* Inherit properties from the whole/raw dev_t */
133 	dev->si_disk = pdev->si_disk;
134 	dev->si_drv1 = pdev->si_drv1;
135 	dev->si_drv2 = pdev->si_drv2;
136 	dev->si_iosize_max = pdev->si_iosize_max;
137 	dev->si_bsize_phys = pdev->si_bsize_phys;
138 	dev->si_bsize_best = pdev->si_bsize_best;
139 
140 	if (error)
141 		goto out;
142 
143 	error = dsopen(dev, devtype, dp->d_dsflags, &dp->d_slice, &dp->d_label);
144 
145 	if (!dsisopen(dp->d_slice))
146 		dp->d_devsw->d_close(pdev, oflags, devtype, p);
147 out:
148 	dp->d_flags &= ~DISKFLAG_LOCK;
149 	if (dp->d_flags & DISKFLAG_WANTED) {
150 		dp->d_flags &= ~DISKFLAG_WANTED;
151 		wakeup(dp);
152 	}
153 
154 	return(error);
155 }
156 
157 static int
158 diskclose(dev_t dev, int fflag, int devtype, struct proc *p)
159 {
160 	struct disk *dp;
161 	int error;
162 
163 	error = 0;
164 	dp = dev->si_disk;
165 	dsclose(dev, devtype, dp->d_slice);
166 	if (!dsisopen(dp->d_slice)) {
167 		error = dp->d_devsw->d_close(dp->d_dev, fflag, devtype, p);
168 	}
169 	return (error);
170 }
171 
172 static void
173 diskstrategy(struct buf *bp)
174 {
175 	dev_t pdev;
176 	struct disk *dp;
177 
178 	dp = bp->b_dev->si_disk;
179 	if (!dp) {
180 		pdev = dkmodpart(dkmodslice(bp->b_dev, WHOLE_DISK_SLICE), RAW_PART);
181 		dp = bp->b_dev->si_disk = pdev->si_disk;
182 		bp->b_dev->si_drv1 = pdev->si_drv1;
183 		bp->b_dev->si_drv2 = pdev->si_drv2;
184 		bp->b_dev->si_iosize_max = pdev->si_iosize_max;
185 		bp->b_dev->si_bsize_phys = pdev->si_bsize_phys;
186 		bp->b_dev->si_bsize_best = pdev->si_bsize_best;
187 	}
188 
189 	if (!dp) {
190 		bp->b_error = ENXIO;
191 		bp->b_flags |= B_ERROR;
192 		biodone(bp);
193 		return;
194 	}
195 
196 	if (dscheck(bp, dp->d_slice) <= 0) {
197 		biodone(bp);
198 		return;
199 	}
200 
201 	dp->d_devsw->d_strategy(bp);
202 	return;
203 
204 }
205 
206 static int
207 diskioctl(dev_t dev, u_long cmd, caddr_t data, int fflag, struct proc *p)
208 {
209 	struct disk *dp;
210 	int error;
211 
212 	dp = dev->si_disk;
213 	error = dsioctl(dev, cmd, data, fflag, &dp->d_slice);
214 	if (error == ENOIOCTL)
215 		error = dp->d_devsw->d_ioctl(dev, cmd, data, fflag, p);
216 	return (error);
217 }
218 
219 static int
220 diskpsize(dev_t dev)
221 {
222 	struct disk *dp;
223 	dev_t pdev;
224 
225 	dp = dev->si_disk;
226 	if (!dp) {
227 		pdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
228 		dp = pdev->si_disk;
229 		dev->si_drv1 = pdev->si_drv1;
230 		dev->si_drv2 = pdev->si_drv2;
231 		/* XXX: don't set bp->b_dev->si_disk (?) */
232 	}
233 	return (dssize(dev, &dp->d_slice));
234 }
235 
236 SYSCTL_DECL(_debug_sizeof);
237 
238 SYSCTL_INT(_debug_sizeof, OID_AUTO, disklabel, CTLFLAG_RD,
239     0, sizeof(struct disklabel), "sizeof(struct disklabel)");
240 
241 SYSCTL_INT(_debug_sizeof, OID_AUTO, diskslices, CTLFLAG_RD,
242     0, sizeof(struct diskslices), "sizeof(struct diskslices)");
243 
244 SYSCTL_INT(_debug_sizeof, OID_AUTO, disk, CTLFLAG_RD,
245     0, sizeof(struct disk), "sizeof(struct disk)");
246