Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 #include <linux/delay.h>
  2 #include <linux/raid/md_u.h>
  3 #include <linux/raid/md_p.h>
  4 
  5 #include "do_mounts.h"
  6 
  7 /*
  8  * When md (and any require personalities) are compiled into the kernel
  9  * (not a module), arrays can be assembles are boot time using with AUTODETECT
 10  * where specially marked partitions are registered with md_autodetect_dev(),
 11  * and with MD_BOOT where devices to be collected are given on the boot line
 12  * with md=.....
 13  * The code for that is here.
 14  */
 15 
 16 #ifdef CONFIG_MD_AUTODETECT
 17 static int __initdata raid_noautodetect;
 18 #else
 19 static int __initdata raid_noautodetect=1;
 20 #endif
 21 static int __initdata raid_autopart;
 22 
 23 static struct {
 24         int minor;
 25         int partitioned;
 26         int level;
 27         int chunk;
 28         char *device_names;
 29 } md_setup_args[256] __initdata;
 30 
 31 static int md_setup_ents __initdata;
 32 
 33 /*
 34  * Parse the command-line parameters given our kernel, but do not
 35  * actually try to invoke the MD device now; that is handled by
 36  * md_setup_drive after the low-level disk drivers have initialised.
 37  *
 38  * 27/11/1999: Fixed to work correctly with the 2.3 kernel (which
 39  *             assigns the task of parsing integer arguments to the
 40  *             invoked program now).  Added ability to initialise all
 41  *             the MD devices (by specifying multiple "md=" lines)
 42  *             instead of just one.  -- KTK
 43  * 18May2000: Added support for persistent-superblock arrays:
 44  *             md=n,0,factor,fault,device-list   uses RAID0 for device n
 45  *             md=n,-1,factor,fault,device-list  uses LINEAR for device n
 46  *             md=n,device-list      reads a RAID superblock from the devices
 47  *             elements in device-list are read by name_to_kdev_t so can be
 48  *             a hex number or something like /dev/hda1 /dev/sdb
 49  * 2001-06-03: Dave Cinege <dcinege@psychosis.com>
 50  *              Shifted name_to_kdev_t() and related operations to md_set_drive()
 51  *              for later execution. Rewrote section to make devfs compatible.
 52  */
 53 static int __init md_setup(char *str)
 54 {
 55         int minor, level, factor, fault, partitioned = 0;
 56         char *pername = "";
 57         char *str1;
 58         int ent;
 59 
 60         if (*str == 'd') {
 61                 partitioned = 1;
 62                 str++;
 63         }
 64         if (get_option(&str, &minor) != 2) {    /* MD Number */
 65                 printk(KERN_WARNING "md: Too few arguments supplied to md=.\n");
 66                 return 0;
 67         }
 68         str1 = str;
 69         for (ent=0 ; ent< md_setup_ents ; ent++)
 70                 if (md_setup_args[ent].minor == minor &&
 71                     md_setup_args[ent].partitioned == partitioned) {
 72                         printk(KERN_WARNING "md: md=%s%d, Specified more than once. "
 73                                "Replacing previous definition.\n", partitioned?"d":"", minor);
 74                         break;
 75                 }
 76         if (ent >= ARRAY_SIZE(md_setup_args)) {
 77                 printk(KERN_WARNING "md: md=%s%d - too many md initialisations\n", partitioned?"d":"", minor);
 78                 return 0;
 79         }
 80         if (ent >= md_setup_ents)
 81                 md_setup_ents++;
 82         switch (get_option(&str, &level)) {     /* RAID level */
 83         case 2: /* could be 0 or -1.. */
 84                 if (level == 0 || level == LEVEL_LINEAR) {
 85                         if (get_option(&str, &factor) != 2 ||   /* Chunk Size */
 86                                         get_option(&str, &fault) != 2) {
 87                                 printk(KERN_WARNING "md: Too few arguments supplied to md=.\n");
 88                                 return 0;
 89                         }
 90                         md_setup_args[ent].level = level;
 91                         md_setup_args[ent].chunk = 1 << (factor+12);
 92                         if (level ==  LEVEL_LINEAR)
 93                                 pername = "linear";
 94                         else
 95                                 pername = "raid0";
 96                         break;
 97                 }
 98                 /* FALL THROUGH */
 99         case 1: /* the first device is numeric */
100                 str = str1;
101                 /* FALL THROUGH */
102         case 0:
103                 md_setup_args[ent].level = LEVEL_NONE;
104                 pername="super-block";
105         }
106 
107         printk(KERN_INFO "md: Will configure md%d (%s) from %s, below.\n",
108                 minor, pername, str);
109         md_setup_args[ent].device_names = str;
110         md_setup_args[ent].partitioned = partitioned;
111         md_setup_args[ent].minor = minor;
112 
113         return 1;
114 }
115 
116 static void __init md_setup_drive(void)
117 {
118         int minor, i, ent, partitioned;
119         dev_t dev;
120         dev_t devices[MD_SB_DISKS+1];
121 
122         for (ent = 0; ent < md_setup_ents ; ent++) {
123                 int fd;
124                 int err = 0;
125                 char *devname;
126                 mdu_disk_info_t dinfo;
127                 char name[16];
128 
129                 minor = md_setup_args[ent].minor;
130                 partitioned = md_setup_args[ent].partitioned;
131                 devname = md_setup_args[ent].device_names;
132 
133                 sprintf(name, "/dev/md%s%d", partitioned?"_d":"", minor);
134                 if (partitioned)
135                         dev = MKDEV(mdp_major, minor << MdpMinorShift);
136                 else
137                         dev = MKDEV(MD_MAJOR, minor);
138                 create_dev(name, dev);
139                 for (i = 0; i < MD_SB_DISKS && devname != NULL; i++) {
140                         char *p;
141                         char comp_name[64];
142                         u32 rdev;
143 
144                         p = strchr(devname, ',');
145                         if (p)
146                                 *p++ = 0;
147 
148                         dev = name_to_dev_t(devname);
149                         if (strncmp(devname, "/dev/", 5) == 0)
150                                 devname += 5;
151                         snprintf(comp_name, 63, "/dev/%s", devname);
152                         rdev = bstat(comp_name);
153                         if (rdev)
154                                 dev = new_decode_dev(rdev);
155                         if (!dev) {
156                                 printk(KERN_WARNING "md: Unknown device name: %s\n", devname);
157                                 break;
158                         }
159 
160                         devices[i] = dev;
161 
162                         devname = p;
163                 }
164                 devices[i] = 0;
165 
166                 if (!i)
167                         continue;
168 
169                 printk(KERN_INFO "md: Loading md%s%d: %s\n",
170                         partitioned ? "_d" : "", minor,
171                         md_setup_args[ent].device_names);
172 
173                 fd = sys_open(name, 0, 0);
174                 if (fd < 0) {
175                         printk(KERN_ERR "md: open failed - cannot start "
176                                         "array %s\n", name);
177                         continue;
178                 }
179                 if (sys_ioctl(fd, SET_ARRAY_INFO, 0) == -EBUSY) {
180                         printk(KERN_WARNING
181                                "md: Ignoring md=%d, already autodetected. (Use raid=noautodetect)\n",
182                                minor);
183                         sys_close(fd);
184                         continue;
185                 }
186 
187                 if (md_setup_args[ent].level != LEVEL_NONE) {
188                         /* non-persistent */
189                         mdu_array_info_t ainfo;
190                         ainfo.level = md_setup_args[ent].level;
191                         ainfo.size = 0;
192                         ainfo.nr_disks =0;
193                         ainfo.raid_disks =0;
194                         while (devices[ainfo.raid_disks])
195                                 ainfo.raid_disks++;
196                         ainfo.md_minor =minor;
197                         ainfo.not_persistent = 1;
198 
199                         ainfo.state = (1 << MD_SB_CLEAN);
200                         ainfo.layout = 0;
201                         ainfo.chunk_size = md_setup_args[ent].chunk;
202                         err = sys_ioctl(fd, SET_ARRAY_INFO, (long)&ainfo);
203                         for (i = 0; !err && i <= MD_SB_DISKS; i++) {
204                                 dev = devices[i];
205                                 if (!dev)
206                                         break;
207                                 dinfo.number = i;
208                                 dinfo.raid_disk = i;
209                                 dinfo.state = (1<<MD_DISK_ACTIVE)|(1<<MD_DISK_SYNC);
210                                 dinfo.major = MAJOR(dev);
211                                 dinfo.minor = MINOR(dev);
212                                 err = sys_ioctl(fd, ADD_NEW_DISK, (long)&dinfo);
213                         }
214                 } else {
215                         /* persistent */
216                         for (i = 0; i <= MD_SB_DISKS; i++) {
217                                 dev = devices[i];
218                                 if (!dev)
219                                         break;
220                                 dinfo.major = MAJOR(dev);
221                                 dinfo.minor = MINOR(dev);
222                                 sys_ioctl(fd, ADD_NEW_DISK, (long)&dinfo);
223                         }
224                 }
225                 if (!err)
226                         err = sys_ioctl(fd, RUN_ARRAY, 0);
227                 if (err)
228                         printk(KERN_WARNING "md: starting md%d failed\n", minor);
229                 else {
230                         /* reread the partition table.
231                          * I (neilb) and not sure why this is needed, but I cannot
232                          * boot a kernel with devfs compiled in from partitioned md
233                          * array without it
234                          */
235                         sys_close(fd);
236                         fd = sys_open(name, 0, 0);
237                         sys_ioctl(fd, BLKRRPART, 0);
238                 }
239                 sys_close(fd);
240         }
241 }
242 
243 static int __init raid_setup(char *str)
244 {
245         int len, pos;
246 
247         len = strlen(str) + 1;
248         pos = 0;
249 
250         while (pos < len) {
251                 char *comma = strchr(str+pos, ',');
252                 int wlen;
253                 if (comma)
254                         wlen = (comma-str)-pos;
255                 else    wlen = (len-1)-pos;
256 
257                 if (!strncmp(str, "noautodetect", wlen))
258                         raid_noautodetect = 1;
259                 if (!strncmp(str, "autodetect", wlen))
260                         raid_noautodetect = 0;
261                 if (strncmp(str, "partitionable", wlen)==0)
262                         raid_autopart = 1;
263                 if (strncmp(str, "part", wlen)==0)
264                         raid_autopart = 1;
265                 pos += wlen+1;
266         }
267         return 1;
268 }
269 
270 __setup("raid=", raid_setup);
271 __setup("md=", md_setup);
272 
273 static void __init autodetect_raid(void)
274 {
275         int fd;
276 
277         /*
278          * Since we don't want to detect and use half a raid array, we need to
279          * wait for the known devices to complete their probing
280          */
281         printk(KERN_INFO "md: Waiting for all devices to be available before autodetect\n");
282         printk(KERN_INFO "md: If you don't use raid, use raid=noautodetect\n");
283 
284         wait_for_device_probe();
285 
286         fd = sys_open("/dev/md0", 0, 0);
287         if (fd >= 0) {
288                 sys_ioctl(fd, RAID_AUTORUN, raid_autopart);
289                 sys_close(fd);
290         }
291 }
292 
293 void __init md_run_setup(void)
294 {
295         create_dev("/dev/md0", MKDEV(MD_MAJOR, 0));
296 
297         if (raid_noautodetect)
298                 printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=autodetect will force)\n");
299         else
300                 autodetect_raid();
301         md_setup_drive();
302 }
303 
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