Commit 298d8a04 authored by Christoph Hellwig's avatar Christoph Hellwig

[PATCH] umode_t changes from Adam's mini-devfs

The use of umode_t instead of devfs-specific char vs block #defines
in Adam's mini-devfs patch makes sense independant of whether his patch
should get merged.  While reviewing his changes I also notices that
most of the number allocation functionality in devfs has no business
beeing exported.  In addition I cleaned up devfs_alloc_devnum/
devfs_dealloc_devnum a bit.
parent b30d9e8b
......@@ -685,6 +685,8 @@
#include <asm/bitops.h>
#include <asm/atomic.h>
#include "internal.h"
#define DEVFS_VERSION "1.22 (20021013)"
#define DEVFS_NAME "devfs"
......@@ -935,9 +937,9 @@ void devfs_put (devfs_handle_t de)
de->parent ? de->parent->name : "no parent");
if ( S_ISLNK (de->mode) ) kfree (de->u.symlink.linkname);
if ( S_ISCHR (de->mode) && de->u.cdev.autogen )
devfs_dealloc_devnum (DEVFS_SPECIAL_CHR, de->u.cdev.dev);
devfs_dealloc_devnum (de->mode, de->u.cdev.dev);
if ( S_ISBLK (de->mode) && de->u.bdev.autogen )
devfs_dealloc_devnum(DEVFS_SPECIAL_BLK, de->u.bdev.dev);
devfs_dealloc_devnum (de->mode, de->u.bdev.dev);
WRITE_ENTRY_MAGIC (de, 0);
#ifdef CONFIG_DEVFS_DEBUG
spin_lock (&stat_lock);
......@@ -1102,13 +1104,13 @@ static struct devfs_entry *_devfs_get_root_entry (void)
/* And create the entry for ".devfsd" */
if ( ( new = _devfs_alloc_entry (".devfsd", 0, S_IFCHR |S_IRUSR |S_IWUSR) )
== NULL ) return NULL;
new->u.cdev.dev = devfs_alloc_devnum (DEVFS_SPECIAL_CHR);
new->u.cdev.dev = devfs_alloc_devnum (S_IFCHR |S_IRUSR |S_IWUSR);
new->u.cdev.ops = &devfsd_fops;
_devfs_append_entry (root_entry, new, FALSE, NULL);
#ifdef CONFIG_DEVFS_DEBUG
if ( ( new = _devfs_alloc_entry (".stat", 0, S_IFCHR | S_IRUGO | S_IWUGO) )
== NULL ) return NULL;
new->u.cdev.dev = devfs_alloc_devnum (DEVFS_SPECIAL_CHR);
new->u.cdev.dev = devfs_alloc_devnum (S_IFCHR | S_IRUGO | S_IWUGO);
new->u.cdev.ops = &stat_fops;
_devfs_append_entry (root_entry, new, FALSE, NULL);
#endif
......@@ -1469,7 +1471,6 @@ devfs_handle_t devfs_register (devfs_handle_t dir, const char *name,
unsigned int major, unsigned int minor,
umode_t mode, void *ops, void *info)
{
char devtype = S_ISCHR (mode) ? DEVFS_SPECIAL_CHR : DEVFS_SPECIAL_BLK;
int err;
dev_t devnum = 0, dev = MKDEV(major, minor);
struct devfs_entry *de;
......@@ -1497,7 +1498,7 @@ devfs_handle_t devfs_register (devfs_handle_t dir, const char *name,
if ( ( S_ISCHR (mode) || S_ISBLK (mode) ) &&
(flags & DEVFS_FL_AUTO_DEVNUM) )
{
devnum = devfs_alloc_devnum (devtype);
devnum = devfs_alloc_devnum (mode);
if (!devnum) {
PRINTK ("(%s): exhausted %s device numbers\n",
name, S_ISCHR (mode) ? "char" : "block");
......@@ -1508,7 +1509,7 @@ devfs_handle_t devfs_register (devfs_handle_t dir, const char *name,
if ( ( de = _devfs_prepare_leaf (&dir, name, mode) ) == NULL )
{
PRINTK ("(%s): could not prepare leaf\n", name);
if (devnum) devfs_dealloc_devnum (devtype, devnum);
if (devnum) devfs_dealloc_devnum (mode, devnum);
return NULL;
}
if (S_ISCHR (mode)) {
......@@ -1544,7 +1545,7 @@ devfs_handle_t devfs_register (devfs_handle_t dir, const char *name,
{
PRINTK ("(%s): could not append to parent, err: %d\n", name, err);
devfs_put (dir);
if (devnum) devfs_dealloc_devnum (devtype, devnum);
if (devnum) devfs_dealloc_devnum (mode, devnum);
return NULL;
}
DPRINTK (DEBUG_REGISTER, "(%s): de: %p dir: %p \"%s\" pp: %p\n",
......@@ -1953,7 +1954,6 @@ EXPORT_SYMBOL(devfs_mk_symlink);
EXPORT_SYMBOL(devfs_mk_dir);
EXPORT_SYMBOL(devfs_remove);
EXPORT_SYMBOL(devfs_generate_path);
EXPORT_SYMBOL(devfs_only);
/**
......
extern dev_t devfs_alloc_devnum(umode_t mode);
extern void devfs_dealloc_devnum(umode_t mode, dev_t devnum);
......@@ -60,14 +60,18 @@
Copied and used macro for error messages from fs/devfs/base.c
20021013 Richard Gooch <rgooch@atnf.csiro.au>
Documentation fix.
20030101 Adam J. Richter <adam@yggdrasil.com>
Eliminate DEVFS_SPECIAL_{CHR,BLK}. Use mode_t instead.
20030106 Christoph Hellwig <hch@infradead.org>
Rewrite devfs_{,de}alloc_devnum to look like C code.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <asm/bitops.h>
#include "internal.h"
#define PRINTK(format, args...) \
{printk (KERN_ERR "%s" format, __FUNCTION__ , ## args);}
......@@ -145,49 +149,11 @@ static struct major_list char_major_list =
/**
* devfs_alloc_major - Allocate a major number.
* @type: The type of the major (DEVFS_SPECIAL_CHR or DEVFS_SPECIAL_BLK)
* @mode: The file mode (must be block device or character device).
* Returns the allocated major, else -1 if none are available.
* This routine is thread safe and does not block.
*/
int devfs_alloc_major (char type)
{
int major;
struct major_list *list;
list = (type == DEVFS_SPECIAL_CHR) ? &char_major_list : &block_major_list;
spin_lock (&list->lock);
major = find_first_zero_bit (list->bits, 256);
if (major < 256) __set_bit (major, list->bits);
else major = -1;
spin_unlock (&list->lock);
return major;
} /* End Function devfs_alloc_major */
EXPORT_SYMBOL(devfs_alloc_major);
/**
* devfs_dealloc_major - Deallocate a major number.
* @type: The type of the major (DEVFS_SPECIAL_CHR or DEVFS_SPECIAL_BLK)
* @major: The major number.
* This routine is thread safe and does not block.
*/
void devfs_dealloc_major (char type, int major)
{
int was_set;
struct major_list *list;
if (major < 0) return;
list = (type == DEVFS_SPECIAL_CHR) ? &char_major_list : &block_major_list;
spin_lock (&list->lock);
was_set = __test_and_clear_bit (major, list->bits);
spin_unlock (&list->lock);
if (!was_set) PRINTK ("(): major %d was already free\n", major);
} /* End Function devfs_dealloc_major */
EXPORT_SYMBOL(devfs_dealloc_major);
struct minor_list
{
......@@ -196,130 +162,110 @@ struct minor_list
struct minor_list *next;
};
struct device_list
{
struct minor_list *first, *last;
int none_free;
};
static DECLARE_MUTEX (block_semaphore);
static struct device_list block_list;
static struct device_list {
struct minor_list *first;
struct minor_list *last;
int none_free;
} block_list, char_list;
static DECLARE_MUTEX (char_semaphore);
static struct device_list char_list;
static DECLARE_MUTEX(device_list_mutex);
/**
* devfs_alloc_devnum - Allocate a device number.
* @type: The type (DEVFS_SPECIAL_CHR or DEVFS_SPECIAL_BLK).
* @mode: The file mode (must be block device or character device).
*
* Returns the allocated device number, else NODEV if none are available.
* This routine is thread safe and may block.
*/
dev_t devfs_alloc_devnum (char type)
dev_t devfs_alloc_devnum(umode_t mode)
{
int minor;
struct semaphore *semaphore;
struct device_list *list;
struct minor_list *entry;
struct device_list *list;
struct major_list *major_list;
struct minor_list *entry;
int minor;
if (S_ISCHR(mode)) {
major_list = &char_major_list;
list = &char_list;
} else {
major_list = &block_major_list;
list = &block_list;
}
if (type == DEVFS_SPECIAL_CHR)
{
semaphore = &char_semaphore;
list = &char_list;
}
else
{
semaphore = &block_semaphore;
list = &block_list;
}
if (list->none_free) return 0; /* Fast test */
down (semaphore);
if (list->none_free)
{
up (semaphore);
return 0;
}
for (entry = list->first; entry != NULL; entry = entry->next)
{
minor = find_first_zero_bit (entry->bits, 256);
if (minor >= 256) continue;
__set_bit (minor, entry->bits);
up (semaphore);
down(&device_list_mutex);
if (list->none_free)
goto out_unlock;
for (entry = list->first; entry; entry = entry->next) {
minor = find_first_zero_bit (entry->bits, 256);
if (minor >= 256)
continue;
goto out_done;
}
/* Need to allocate a new major */
entry = kmalloc (sizeof *entry, GFP_KERNEL);
if (!entry)
goto out_full;
memset(entry, 0, sizeof *entry);
spin_lock(&major_list->lock);
entry->major = find_first_zero_bit(major_list->bits, 256);
if (entry->major >= 256) {
spin_unlock(&major_list->lock);
kfree(entry);
goto out_full;
}
__set_bit(entry->major, major_list->bits);
spin_unlock(&major_list->lock);
if (!list->first)
list->first = entry;
else
list->last->next = entry;
list->last = entry;
minor = 0;
out_done:
__set_bit(minor, entry->bits);
up(&device_list_mutex);
return MKDEV(entry->major, minor);
}
/* Need to allocate a new major */
if ( ( entry = kmalloc (sizeof *entry, GFP_KERNEL) ) == NULL )
{
list->none_free = 1;
up (semaphore);
return 0;
}
memset (entry, 0, sizeof *entry);
if ( ( entry->major = devfs_alloc_major (type) ) < 0 )
{
out_full:
list->none_free = 1;
up (semaphore);
kfree (entry);
out_unlock:
up(&device_list_mutex);
return 0;
}
__set_bit (0, entry->bits);
if (list->first == NULL) list->first = entry;
else list->last->next = entry;
list->last = entry;
up (semaphore);
return MKDEV(entry->major, 0);
} /* End Function devfs_alloc_devnum */
EXPORT_SYMBOL(devfs_alloc_devnum);
}
/**
* devfs_dealloc_devnum - Dellocate a device number.
* @type: The type (DEVFS_SPECIAL_CHR or DEVFS_SPECIAL_BLK).
* @mode: The file mode (must be block device or character device).
* @devnum: The device number.
*
* This routine is thread safe and may block.
*/
void devfs_dealloc_devnum (char type, dev_t devnum)
void devfs_dealloc_devnum(umode_t mode, dev_t devnum)
{
int major, minor;
struct semaphore *semaphore;
struct device_list *list;
struct minor_list *entry;
if (!devnum) return;
if (type == DEVFS_SPECIAL_CHR)
{
semaphore = &char_semaphore;
list = &char_list;
}
else
{
semaphore = &block_semaphore;
list = &block_list;
}
major = MAJOR (devnum);
minor = MINOR (devnum);
down (semaphore);
for (entry = list->first; entry != NULL; entry = entry->next)
{
int was_set;
if (entry->major != major) continue;
was_set = __test_and_clear_bit (minor, entry->bits);
if (was_set) list->none_free = 0;
up (semaphore);
if (!was_set)
PRINTK ( "(): device %s was already free\n", kdevname (to_kdev_t(devnum)) );
return;
}
up (semaphore);
PRINTK ( "(): major for %s not previously allocated\n",
kdevname (to_kdev_t(devnum)) );
} /* End Function devfs_dealloc_devnum */
EXPORT_SYMBOL(devfs_dealloc_devnum);
struct device_list *list = S_ISCHR(mode) ? &char_list : &block_list;
struct minor_list *entry;
if (!devnum)
return;
down(&device_list_mutex);
for (entry = list->first; entry; entry = entry->next) {
if (entry->major == MAJOR(devnum)) {
if (__test_and_clear_bit(MINOR(devnum), entry->bits))
list->none_free = 0;
break;
}
}
up(&device_list_mutex);
}
/**
......
......@@ -21,9 +21,6 @@
#define DEVFS_FL_DEFAULT DEVFS_FL_NONE
#define DEVFS_SPECIAL_CHR 0
#define DEVFS_SPECIAL_BLK 1
typedef struct devfs_entry * devfs_handle_t;
#ifdef CONFIG_DEVFS_FS
......@@ -58,10 +55,6 @@ extern int devfs_set_file_size (devfs_handle_t de, unsigned long size);
extern int devfs_only (void);
extern int devfs_register_tape (devfs_handle_t de);
extern void devfs_unregister_tape(int num);
extern int devfs_alloc_major (char type);
extern void devfs_dealloc_major (char type, int major);
extern dev_t devfs_alloc_devnum (char type);
extern void devfs_dealloc_devnum (char type, dev_t devnum);
extern int devfs_alloc_unique_number (struct unique_numspace *space);
extern void devfs_dealloc_unique_number (struct unique_numspace *space,
int number);
......@@ -129,41 +122,18 @@ static inline int devfs_register_tape (devfs_handle_t de)
static inline void devfs_unregister_tape(int num)
{
}
static inline int devfs_alloc_major (char type)
{
return -1;
}
static inline void devfs_dealloc_major (char type, int major)
{
return;
}
static inline dev_t devfs_alloc_devnum (char type)
{
return 0;
}
static inline void devfs_dealloc_devnum (char type, dev_t devnum)
{
return;
}
static inline int devfs_alloc_unique_number (struct unique_numspace *space)
{
return -1;
}
static inline void devfs_dealloc_unique_number (struct unique_numspace *space,
int number)
{
return;
}
static inline void mount_devfs_fs (void)
{
return;
}
#endif /* CONFIG_DEVFS_FS */
#endif /* _LINUX_DEVFS_FS_KERNEL_H */
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