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[/] [or1k/] [trunk/] [uclinux/] [uClinux-2.0.x/] [fs/] [devices.c] - Blame information for rev 1765

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/*
 *  linux/fs/devices.c
 *
 * (C) 1993 Matthias Urlichs -- collected common code and tables.
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  Added kerneld support: Jacques Gelinas and Bjorn Ekwall
 */
 
#include <linux/config.h>
#include <linux/fs.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/ext_fs.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
#include <linux/errno.h>
#ifdef CONFIG_KERNELD
#include <linux/kerneld.h>
 
#include <linux/tty.h>
 
/* serial module kerneld load support */
struct tty_driver *get_tty_driver(kdev_t device);
#define isa_tty_dev(ma) (ma == TTY_MAJOR || ma == TTYAUX_MAJOR)
#define need_serial(ma,mi) (get_tty_driver(MKDEV(ma,mi)) == NULL)
#endif
 
struct device_struct {
        const char * name;
        struct file_operations * fops;
};
 
static struct device_struct chrdevs[MAX_CHRDEV] = {
        { NULL, NULL },
};
 
static struct device_struct blkdevs[MAX_BLKDEV] = {
        { NULL, NULL },
};
 
int get_device_list(char * page)
{
        int i;
        int len;
 
        len = sprintf(page, "Character devices:\n");
        for (i = 0; i < MAX_CHRDEV ; i++) {
                if (chrdevs[i].fops) {
                        len += sprintf(page+len, "%2d %s\n", i, chrdevs[i].name);
                }
        }
        len += sprintf(page+len, "\nBlock devices:\n");
        for (i = 0; i < MAX_BLKDEV ; i++) {
                if (blkdevs[i].fops) {
                        len += sprintf(page+len, "%2d %s\n", i, blkdevs[i].name);
                }
        }
        return len;
}
 
/*
        Return the function table of a device.
        Load the driver if needed.
*/
static struct file_operations * get_fops(
        unsigned int major,
        unsigned int minor,
        unsigned int maxdev,
        const char *mangle,             /* String to use to build the module name */
        struct device_struct tb[])
{
        struct file_operations *ret = NULL;
 
        if (major < maxdev){
#ifdef CONFIG_KERNELD
                /*
                 * I do get request for device 0. I have no idea why. It happen
                 * at shutdown time for one. Without the following test, the
                 * kernel will happily trigger a request_module() which will
                 * trigger kerneld and modprobe for nothing (since there
                 * is no device with major number == 0. And furthermore
                 * it locks the reboot process :-(
                 *
                 * Jacques Gelinas (jacques@solucorp.qc.ca)
                 *
                 * A. Haritsis <ah@doc.ic.ac.uk>: fix for serial module
                 *  though we need the minor here to check if serial dev,
                 *  we pass only the normal major char dev to kerneld
                 *  as there is no other loadable dev on these majors
                 */
                if ((isa_tty_dev(major) && need_serial(major,minor)) ||
                    (major != 0 && !tb[major].fops)) {
                        char name[20];
                        sprintf(name, mangle, major);
                        request_module(name);
                }
#endif
                ret = tb[major].fops;
        }
        return ret;
}
 
 
/*
        Return the function table of a device.
        Load the driver if needed.
*/
struct file_operations * get_blkfops(unsigned int major)
{
        return get_fops (major,0,MAX_BLKDEV,"block-major-%d",blkdevs);
}
 
struct file_operations * get_chrfops(unsigned int major, unsigned int minor)
{
        return get_fops (major,minor,MAX_CHRDEV,"char-major-%d",chrdevs);
}
 
int register_chrdev(unsigned int major, const char * name, struct file_operations *fops)
{
        if (major == 0) {
                for (major = MAX_CHRDEV-1; major > 0; major--) {
                        if (chrdevs[major].fops == NULL) {
                                chrdevs[major].name = name;
                                chrdevs[major].fops = fops;
                                return major;
                        }
                }
                return -EBUSY;
        }
        if (major >= MAX_CHRDEV)
                return -EINVAL;
        if (chrdevs[major].fops && chrdevs[major].fops != fops)
                return -EBUSY;
        chrdevs[major].name = name;
        chrdevs[major].fops = fops;
        return 0;
}
 
int register_blkdev(unsigned int major, const char * name, struct file_operations *fops)
{
        if (major == 0) {
                for (major = MAX_BLKDEV-1; major > 0; major--) {
                        if (blkdevs[major].fops == NULL) {
                                blkdevs[major].name = name;
                                blkdevs[major].fops = fops;
                                return major;
                        }
                }
                return -EBUSY;
        }
        if (major >= MAX_BLKDEV)
                return -EINVAL;
        if (blkdevs[major].fops && blkdevs[major].fops != fops)
                return -EBUSY;
        blkdevs[major].name = name;
        blkdevs[major].fops = fops;
        return 0;
}
 
int unregister_chrdev(unsigned int major, const char * name)
{
        if (major >= MAX_CHRDEV)
                return -EINVAL;
        if (!chrdevs[major].fops)
                return -EINVAL;
        if (strcmp(chrdevs[major].name, name))
                return -EINVAL;
        chrdevs[major].name = NULL;
        chrdevs[major].fops = NULL;
        return 0;
}
 
int unregister_blkdev(unsigned int major, const char * name)
{
        if (major >= MAX_BLKDEV)
                return -EINVAL;
        if (!blkdevs[major].fops)
                return -EINVAL;
        if (strcmp(blkdevs[major].name, name))
                return -EINVAL;
        blkdevs[major].name = NULL;
        blkdevs[major].fops = NULL;
        return 0;
}
 
/*
 * This routine checks whether a removable media has been changed,
 * and invalidates all buffer-cache-entries in that case. This
 * is a relatively slow routine, so we have to try to minimize using
 * it. Thus it is called only upon a 'mount' or 'open'. This
 * is the best way of combining speed and utility, I think.
 * People changing diskettes in the middle of an operation deserve
 * to loose :-)
 */
int check_disk_change(kdev_t dev)
{
        int i;
        struct file_operations * fops;
 
        i = MAJOR(dev);
        if (i >= MAX_BLKDEV || (fops = blkdevs[i].fops) == NULL)
                return 0;
        if (fops->check_media_change == NULL)
                return 0;
        if (!fops->check_media_change(dev))
                return 0;
 
        printk(KERN_DEBUG "VFS: Disk change detected on device %s\n",
                kdevname(dev));
        for (i=0 ; i<NR_SUPER ; i++)
                if (super_blocks[i].s_dev == dev)
                        put_super(super_blocks[i].s_dev);
        invalidate_inodes(dev);
        invalidate_buffers(dev);
 
        if (fops->revalidate)
                fops->revalidate(dev);
        return 1;
}
 
/*
 * Called every time a block special file is opened
 */
int blkdev_open(struct inode * inode, struct file * filp)
{
        int ret = -ENODEV;
 
        if (securelevel > 0 && (filp->f_mode & FMODE_WRITE))
                return -EACCES; /* cevans */
 
        filp->f_op = get_blkfops(MAJOR(inode->i_rdev));
        if (filp->f_op != NULL){
                ret = 0;
                if (filp->f_op->open != NULL)
                        ret = filp->f_op->open(inode,filp);
        }
        return ret;
}
 
void blkdev_release(struct inode * inode)
{
        struct file_operations *fops = get_blkfops(MAJOR(inode->i_rdev));
        if (fops && fops->release)
                fops->release(inode,NULL);
}
 
 
/*
 * Dummy default file-operations: the only thing this does
 * is contain the open that then fills in the correct operations
 * depending on the special file...
 */
struct file_operations def_blk_fops = {
        NULL,           /* lseek */
        NULL,           /* read */
        NULL,           /* write */
        NULL,           /* readdir */
        NULL,           /* select */
        NULL,           /* ioctl */
        NULL,           /* mmap */
        blkdev_open,    /* open */
        NULL,           /* release */
};
 
struct inode_operations blkdev_inode_operations = {
        &def_blk_fops,          /* default file operations */
        NULL,                   /* create */
        NULL,                   /* lookup */
        NULL,                   /* link */
        NULL,                   /* unlink */
        NULL,                   /* symlink */
        NULL,                   /* mkdir */
        NULL,                   /* rmdir */
        NULL,                   /* mknod */
        NULL,                   /* rename */
        NULL,                   /* readlink */
        NULL,                   /* follow_link */
        NULL,                   /* readpage */
        NULL,                   /* writepage */
        NULL,                   /* bmap */
        NULL,                   /* truncate */
        NULL                    /* permission */
};
 
/*
 * Called every time a character special file is opened
 */
int chrdev_open(struct inode * inode, struct file * filp)
{
        int ret = -ENODEV;
 
        filp->f_op = get_chrfops(MAJOR(inode->i_rdev), MINOR(inode->i_rdev));
        if (filp->f_op != NULL){
                ret = 0;
                if (filp->f_op->open != NULL)
                        ret = filp->f_op->open(inode,filp);
        }
        return ret;
}
 
/*
 * Dummy default file-operations: the only thing this does
 * is contain the open that then fills in the correct operations
 * depending on the special file...
 */
struct file_operations def_chr_fops = {
        NULL,           /* lseek */
        NULL,           /* read */
        NULL,           /* write */
        NULL,           /* readdir */
        NULL,           /* select */
        NULL,           /* ioctl */
        NULL,           /* mmap */
        chrdev_open,    /* open */
        NULL,           /* release */
};
 
struct inode_operations chrdev_inode_operations = {
        &def_chr_fops,          /* default file operations */
        NULL,                   /* create */
        NULL,                   /* lookup */
        NULL,                   /* link */
        NULL,                   /* unlink */
        NULL,                   /* symlink */
        NULL,                   /* mkdir */
        NULL,                   /* rmdir */
        NULL,                   /* mknod */
        NULL,                   /* rename */
        NULL,                   /* readlink */
        NULL,                   /* follow_link */
        NULL,                   /* readpage */
        NULL,                   /* writepage */
        NULL,                   /* bmap */
        NULL,                   /* truncate */
        NULL                    /* permission */
};
 
/*
 * Print device name (in decimal, hexadecimal or symbolic) -
 * at present hexadecimal only.
 * Note: returns pointer to static data!
 */
char * kdevname(kdev_t dev)
{
        static char buffer[32];
        sprintf(buffer, "%02x:%02x", MAJOR(dev), MINOR(dev));
        return buffer;
}

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[/] [or1k/] [trunk/] [uclinux/] [uClinux-2.0.x/] [fs/] [devices.c] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	199	simons	`/*`
2			`* linux/fs/devices.c`
3			`*`
4			`* (C) 1993 Matthias Urlichs -- collected common code and tables.`
5			`*`
6			`* Copyright (C) 1991, 1992 Linus Torvalds`
7			`*`
8			`* Added kerneld support: Jacques Gelinas and Bjorn Ekwall`
9			`*/`
10
11			`#include <linux/config.h>`
12			`#include <linux/fs.h>`
13			`#include <linux/major.h>`
14			`#include <linux/string.h>`
15			`#include <linux/sched.h>`
16			`#include <linux/ext_fs.h>`
17			`#include <linux/stat.h>`
18			`#include <linux/fcntl.h>`
19			`#include <linux/errno.h>`
20			`#ifdef CONFIG_KERNELD`
21			`#include <linux/kerneld.h>`
22
23			`#include <linux/tty.h>`
24
25			`/* serial module kerneld load support */`
26			`struct tty_driver *get_tty_driver(kdev_t device);`
27			`#define isa_tty_dev(ma) (ma == TTY_MAJOR \|\| ma == TTYAUX_MAJOR)`
28			`#define need_serial(ma,mi) (get_tty_driver(MKDEV(ma,mi)) == NULL)`
29			`#endif`
30
31			`struct device_struct {`
32			`const char * name;`
33			`struct file_operations * fops;`
34			`};`
35
36			`static struct device_struct chrdevs[MAX_CHRDEV] = {`
37			`{ NULL, NULL },`
38			`};`
39
40			`static struct device_struct blkdevs[MAX_BLKDEV] = {`
41			`{ NULL, NULL },`
42			`};`
43
44			`int get_device_list(char * page)`
45			`{`
46			`int i;`
47			`int len;`
48
49			`len = sprintf(page, "Character devices:\n");`
50			`for (i = 0; i < MAX_CHRDEV ; i++) {`
51			`if (chrdevs[i].fops) {`
52			`len += sprintf(page+len, "%2d %s\n", i, chrdevs[i].name);`
53			`}`
54			`}`
55			`len += sprintf(page+len, "\nBlock devices:\n");`
56			`for (i = 0; i < MAX_BLKDEV ; i++) {`
57			`if (blkdevs[i].fops) {`
58			`len += sprintf(page+len, "%2d %s\n", i, blkdevs[i].name);`
59			`}`
60			`}`
61			`return len;`
62			`}`
63
64			`/*`
65			`Return the function table of a device.`
66			`Load the driver if needed.`
67			`*/`
68			`static struct file_operations * get_fops(`
69			`unsigned int major,`
70			`unsigned int minor,`
71			`unsigned int maxdev,`
72			`const char mangle, / String to use to build the module name */`
73			`struct device_struct tb[])`
74			`{`
75			`struct file_operations *ret = NULL;`
76
77			`if (major < maxdev){`
78			`#ifdef CONFIG_KERNELD`
79			`/*`
80			`* I do get request for device 0. I have no idea why. It happen`
81			`* at shutdown time for one. Without the following test, the`
82			`* kernel will happily trigger a request_module() which will`
83			`* trigger kerneld and modprobe for nothing (since there`
84			`* is no device with major number == 0. And furthermore`
85			`* it locks the reboot process :-(`
86			`*`
87			`* Jacques Gelinas (jacques@solucorp.qc.ca)`
88			`*`
89			`* A. Haritsis <ah@doc.ic.ac.uk>: fix for serial module`
90			`* though we need the minor here to check if serial dev,`
91			`* we pass only the normal major char dev to kerneld`
92			`* as there is no other loadable dev on these majors`
93			`*/`
94			`if ((isa_tty_dev(major) && need_serial(major,minor)) \|\|`
95			`(major != 0 && !tb[major].fops)) {`
96			`char name[20];`
97			`sprintf(name, mangle, major);`
98			`request_module(name);`
99			`}`
100			`#endif`
101			`ret = tb[major].fops;`
102			`}`
103			`return ret;`
104			`}`
105
106
107			`/*`
108			`Return the function table of a device.`
109			`Load the driver if needed.`
110			`*/`
111			`struct file_operations * get_blkfops(unsigned int major)`
112			`{`
113			`return get_fops (major,0,MAX_BLKDEV,"block-major-%d",blkdevs);`
114			`}`
115
116			`struct file_operations * get_chrfops(unsigned int major, unsigned int minor)`
117			`{`
118			`return get_fops (major,minor,MAX_CHRDEV,"char-major-%d",chrdevs);`
119			`}`
120
121			`int register_chrdev(unsigned int major, const char * name, struct file_operations *fops)`
122			`{`
123			`if (major == 0) {`
124			`for (major = MAX_CHRDEV-1; major > 0; major--) {`
125			`if (chrdevs[major].fops == NULL) {`
126			`chrdevs[major].name = name;`
127			`chrdevs[major].fops = fops;`
128			`return major;`
129			`}`
130			`}`
131			`return -EBUSY;`
132			`}`
133			`if (major >= MAX_CHRDEV)`
134			`return -EINVAL;`
135			`if (chrdevs[major].fops && chrdevs[major].fops != fops)`
136			`return -EBUSY;`
137			`chrdevs[major].name = name;`
138			`chrdevs[major].fops = fops;`
139			`return 0;`
140			`}`
141
142			`int register_blkdev(unsigned int major, const char * name, struct file_operations *fops)`
143			`{`
144			`if (major == 0) {`
145			`for (major = MAX_BLKDEV-1; major > 0; major--) {`
146			`if (blkdevs[major].fops == NULL) {`
147			`blkdevs[major].name = name;`
148			`blkdevs[major].fops = fops;`
149			`return major;`
150			`}`
151			`}`
152			`return -EBUSY;`
153			`}`
154			`if (major >= MAX_BLKDEV)`
155			`return -EINVAL;`
156			`if (blkdevs[major].fops && blkdevs[major].fops != fops)`
157			`return -EBUSY;`
158			`blkdevs[major].name = name;`
159			`blkdevs[major].fops = fops;`
160			`return 0;`
161			`}`
162
163			`int unregister_chrdev(unsigned int major, const char * name)`
164			`{`
165			`if (major >= MAX_CHRDEV)`
166			`return -EINVAL;`
167			`if (!chrdevs[major].fops)`
168			`return -EINVAL;`
169			`if (strcmp(chrdevs[major].name, name))`
170			`return -EINVAL;`
171			`chrdevs[major].name = NULL;`
172			`chrdevs[major].fops = NULL;`
173			`return 0;`
174			`}`
175
176			`int unregister_blkdev(unsigned int major, const char * name)`
177			`{`
178			`if (major >= MAX_BLKDEV)`
179			`return -EINVAL;`
180			`if (!blkdevs[major].fops)`
181			`return -EINVAL;`
182			`if (strcmp(blkdevs[major].name, name))`
183			`return -EINVAL;`
184			`blkdevs[major].name = NULL;`
185			`blkdevs[major].fops = NULL;`
186			`return 0;`
187			`}`
188
189			`/*`
190			`* This routine checks whether a removable media has been changed,`
191			`* and invalidates all buffer-cache-entries in that case. This`
192			`* is a relatively slow routine, so we have to try to minimize using`
193			`* it. Thus it is called only upon a 'mount' or 'open'. This`
194			`* is the best way of combining speed and utility, I think.`
195			`* People changing diskettes in the middle of an operation deserve`
196			`* to loose :-)`
197			`*/`
198			`int check_disk_change(kdev_t dev)`
199			`{`
200			`int i;`
201			`struct file_operations * fops;`
202
203			`i = MAJOR(dev);`
204			`if (i >= MAX_BLKDEV \|\| (fops = blkdevs[i].fops) == NULL)`
205			`return 0;`
206			`if (fops->check_media_change == NULL)`
207			`return 0;`
208			`if (!fops->check_media_change(dev))`
209			`return 0;`
210
211			`printk(KERN_DEBUG "VFS: Disk change detected on device %s\n",`
212			`kdevname(dev));`
213			`for (i=0 ; i<NR_SUPER ; i++)`
214			`if (super_blocks[i].s_dev == dev)`
215			`put_super(super_blocks[i].s_dev);`
216			`invalidate_inodes(dev);`
217			`invalidate_buffers(dev);`
218
219			`if (fops->revalidate)`
220			`fops->revalidate(dev);`
221			`return 1;`
222			`}`
223
224			`/*`
225			`* Called every time a block special file is opened`
226			`*/`
227			`int blkdev_open(struct inode * inode, struct file * filp)`
228			`{`
229			`int ret = -ENODEV;`
230
231			`if (securelevel > 0 && (filp->f_mode & FMODE_WRITE))`
232			`return -EACCES; /* cevans */`
233
234			`filp->f_op = get_blkfops(MAJOR(inode->i_rdev));`
235			`if (filp->f_op != NULL){`
236			`ret = 0;`
237			`if (filp->f_op->open != NULL)`
238			`ret = filp->f_op->open(inode,filp);`
239			`}`
240			`return ret;`
241			`}`
242
243			`void blkdev_release(struct inode * inode)`
244			`{`
245			`struct file_operations *fops = get_blkfops(MAJOR(inode->i_rdev));`
246			`if (fops && fops->release)`
247			`fops->release(inode,NULL);`
248			`}`
249
250
251			`/*`
252			`* Dummy default file-operations: the only thing this does`
253			`* is contain the open that then fills in the correct operations`
254			`* depending on the special file...`
255			`*/`
256			`struct file_operations def_blk_fops = {`
257			`NULL, /* lseek */`
258			`NULL, /* read */`
259			`NULL, /* write */`
260			`NULL, /* readdir */`
261			`NULL, /* select */`
262			`NULL, /* ioctl */`
263			`NULL, /* mmap */`
264			`blkdev_open, /* open */`
265			`NULL, /* release */`
266			`};`
267
268			`struct inode_operations blkdev_inode_operations = {`
269			`&def_blk_fops, /* default file operations */`
270			`NULL, /* create */`
271			`NULL, /* lookup */`
272			`NULL, /* link */`
273			`NULL, /* unlink */`
274			`NULL, /* symlink */`
275			`NULL, /* mkdir */`
276			`NULL, /* rmdir */`
277			`NULL, /* mknod */`
278			`NULL, /* rename */`
279			`NULL, /* readlink */`
280			`NULL, /* follow_link */`
281			`NULL, /* readpage */`
282			`NULL, /* writepage */`
283			`NULL, /* bmap */`
284			`NULL, /* truncate */`
285			`NULL /* permission */`
286			`};`
287
288			`/*`
289			`* Called every time a character special file is opened`
290			`*/`
291			`int chrdev_open(struct inode * inode, struct file * filp)`
292			`{`
293			`int ret = -ENODEV;`
294
295			`filp->f_op = get_chrfops(MAJOR(inode->i_rdev), MINOR(inode->i_rdev));`
296			`if (filp->f_op != NULL){`
297			`ret = 0;`
298			`if (filp->f_op->open != NULL)`
299			`ret = filp->f_op->open(inode,filp);`
300			`}`
301			`return ret;`
302			`}`
303
304			`/*`
305			`* Dummy default file-operations: the only thing this does`
306			`* is contain the open that then fills in the correct operations`
307			`* depending on the special file...`
308			`*/`
309			`struct file_operations def_chr_fops = {`
310			`NULL, /* lseek */`
311			`NULL, /* read */`
312			`NULL, /* write */`
313			`NULL, /* readdir */`
314			`NULL, /* select */`
315			`NULL, /* ioctl */`
316			`NULL, /* mmap */`
317			`chrdev_open, /* open */`
318			`NULL, /* release */`
319			`};`
320
321			`struct inode_operations chrdev_inode_operations = {`
322			`&def_chr_fops, /* default file operations */`
323			`NULL, /* create */`
324			`NULL, /* lookup */`
325			`NULL, /* link */`
326			`NULL, /* unlink */`
327			`NULL, /* symlink */`
328			`NULL, /* mkdir */`
329			`NULL, /* rmdir */`
330			`NULL, /* mknod */`
331			`NULL, /* rename */`
332			`NULL, /* readlink */`
333			`NULL, /* follow_link */`
334			`NULL, /* readpage */`
335			`NULL, /* writepage */`
336			`NULL, /* bmap */`
337			`NULL, /* truncate */`
338			`NULL /* permission */`
339			`};`
340
341			`/*`
342			`* Print device name (in decimal, hexadecimal or symbolic) -`
343			`* at present hexadecimal only.`
344			`* Note: returns pointer to static data!`
345			`*/`
346			`char * kdevname(kdev_t dev)`
347			`{`
348			`static char buffer[32];`
349			`sprintf(buffer, "%02x:%02x", MAJOR(dev), MINOR(dev));`
350			`return buffer;`
351			`}`