[PATCH] remove DEVFS_FL_REMOVABLE

Devfs tries to be super smart and rereads partition tables at all
kinds of wierd points.  This breaks a bunch of stuff were you
can't get the right disk changed information (i.e. CompactFlash).

If people actually need this kind of stuff they should just call partx
from devfsd instead of relying on the kernel doing something like this.

Cleans up the devfs code significatnly (aka removes tons of junk)

arch/um/drivers/ubd_kern.c

@@ -507,7 +507,7 @@ static int ubd_new_disk(int major, u64 size, char *name, int unit,
 	/* /dev/ubd/N style names */
 	sprintf(devfs_name, "%d", unit);
 	*handle_out = devfs_register(dir_handle, devfs_name,
-				     DEVFS_FL_REMOVABLE, major, minor,
+				     0, major, minor,
 				     S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP |
 				     S_IWGRP, &ubd_blops, NULL);
 	disk->private_data = &ubd_dev[unit];

fs/devfs/base.c

@@ -758,7 +758,6 @@ struct directory_type
     rwlock_t lock;                   /*  Lock for searching(R)/updating(W)   */
     struct devfs_entry *first;
     struct devfs_entry *last;
-    unsigned short num_removable;    /*  Lock for writing but not reading    */
     unsigned char no_more_additions:1;
 };
 
@@ -766,7 +765,6 @@ struct bdev_type
 {
     struct block_device_operations *ops;
     dev_t dev;
-    unsigned char removable:1;
 };
 
 struct cdev_type
@@ -1017,7 +1015,6 @@ static struct devfs_entry *_devfs_alloc_entry (const char *name,
  *	_devfs_append_entry - Append a devfs entry to a directory's child list.
  *	@dir:  The directory to add to.
  *	@de:  The devfs entry to append.
- *	@removable: If TRUE, increment the count of removable devices for %dir.
  *	@old_de: If an existing entry exists, it will be written here. This may
  *		 be %NULL. An implicit devfs_get() is performed on this entry.
  *
@@ -1028,7 +1025,7 @@ static struct devfs_entry *_devfs_alloc_entry (const char *name,
  */
 
 static int _devfs_append_entry (devfs_handle_t dir, devfs_handle_t de,
-				int removable, devfs_handle_t *old_de)
+				devfs_handle_t *old_de)
 {
     int retval;
 
@@ -1056,7 +1053,6 @@ static int _devfs_append_entry (devfs_handle_t dir, devfs_handle_t de,
 	    if (dir->u.dir.first == NULL) dir->u.dir.first = de;
 	    else dir->u.dir.last->next = de;
 	    dir->u.dir.last = de;
-	    if (removable) ++dir->u.dir.num_removable;
 	    retval = 0;
 	}
 	else retval = -EEXIST;
@@ -1095,13 +1091,13 @@ static struct devfs_entry *_devfs_get_root_entry (void)
 	 == NULL ) return NULL;
     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);
+    _devfs_append_entry (root_entry, new, 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 (S_IFCHR | S_IRUGO | S_IWUGO);
     new->u.cdev.ops = &stat_fops;
-    _devfs_append_entry (root_entry, new, FALSE, NULL);
+    _devfs_append_entry (root_entry, new, NULL);
 #endif
     return root_entry;
 }   /*  End Function _devfs_get_root_entry  */
@@ -1164,7 +1160,7 @@ static devfs_handle_t _devfs_make_parent_for_leaf (struct devfs_entry *dir,
 	{
 	    de = _devfs_alloc_entry (name, next_pos, MODE_DIR);
 	    devfs_get (de);
-	    if ( !de || _devfs_append_entry (dir, de, FALSE, &old) )
+	    if ( !de || _devfs_append_entry (dir, de, &old) )
 	    {
 		devfs_put (de);
 		if ( !old || !S_ISDIR (old->mode) )
@@ -1498,7 +1494,6 @@ devfs_handle_t devfs_register (devfs_handle_t dir, const char *name,
 	de->u.bdev.dev = dev;
 	de->u.cdev.autogen = devnum != 0;
 	de->u.bdev.ops = ops;
-	if (flags & DEVFS_FL_REMOVABLE) de->u.bdev.removable = TRUE;
     } else {
 	PRINTK ("(%s): illegal mode: %x\n", name, mode);
 	devfs_put (de);
@@ -1516,7 +1511,7 @@ devfs_handle_t devfs_register (devfs_handle_t dir, const char *name,
 	de->inode.uid = 0;
 	de->inode.gid = 0;
     }
-    err = _devfs_append_entry(dir, de, flags & DEVFS_FL_REMOVABLE, NULL);
+    err = _devfs_append_entry(dir, de, NULL);
     if (err)
     {
 	PRINTK ("(%s): could not append to parent, err: %d\n", name, err);
@@ -1553,8 +1548,6 @@ static int _devfs_unhook (struct devfs_entry *de)
     else de->next->prev = de->prev;
     de->prev = de;          /*  Indicate we're unhooked                      */
     de->next = NULL;        /*  Force early termination for <devfs_readdir>  */
-    if (S_ISBLK (de->mode) && de->u.bdev.removable )
-	--parent->u.dir.num_removable;
     return TRUE;
 }   /*  End Function _devfs_unhook  */
 
@@ -1648,7 +1641,7 @@ static int devfs_do_symlink (devfs_handle_t dir, const char *name,
     de->info = info;
     de->u.symlink.linkname = newlink;
     de->u.symlink.length = linklength;
-    if ( ( err = _devfs_append_entry (dir, de, FALSE, NULL) ) != 0 )
+    if ( ( err = _devfs_append_entry (dir, de, NULL) ) != 0 )
     {
 	PRINTK ("(%s): could not append to parent, err: %d\n", name, err);
 	devfs_put (dir);
@@ -1725,7 +1718,7 @@ devfs_handle_t devfs_mk_dir (devfs_handle_t dir, const char *name, void *info)
 	return NULL;
     }
     de->info = info;
-    if ( ( err = _devfs_append_entry (dir, de, FALSE, &old) ) != 0 )
+    if ( ( err = _devfs_append_entry (dir, de, &old) ) != 0 )
     {
 	PRINTK ("(%s): could not append to dir: %p \"%s\", err: %d\n",
 		name, dir, dir->name, err);
@@ -1924,102 +1917,6 @@ static int try_modload (struct devfs_entry *parent, struct fs_info *fs_info,
 }   /*  End Function try_modload  */
 
 
-/**
- *	check_disc_changed - Check if a removable disc was changed.
- *	@de: The device.
- *
- *	Returns 1 if the media was changed, else 0.
- *
- *	This function may block, and may indirectly cause the parent directory
- *	contents to be changed due to partition re-reading.
- */
-
-static int check_disc_changed (struct devfs_entry *de)
-{
-	int tmp;
-	int retval = 0;
-	dev_t dev = de->u.bdev.dev;
-	extern int warn_no_part;
-
-	if (!S_ISBLK(de->mode))
-		return 0;
-	/* Ugly hack to disable messages about unable to read partition table */
-	tmp = warn_no_part;
-	warn_no_part = 0;
-	retval = __check_disk_change(dev);
-	warn_no_part = tmp;
-	return retval;
-}   /*  End Function check_disc_changed  */
-
-/**
- *	scan_dir_for_removable - Scan a directory for removable media devices and check media.
- *	@dir: The directory.
- *
- *	This function may block, and may indirectly cause the directory
- *	contents to be changed due to partition re-reading. The directory will
- *	be locked for reading.
- */
-
-static void scan_dir_for_removable (struct devfs_entry *dir)
-{
-    struct devfs_entry *de;
-
-    read_lock (&dir->u.dir.lock);
-    if (dir->u.dir.num_removable < 1) de = NULL;
-    else
-    {
-	for (de = dir->u.dir.first; de != NULL; de = de->next)
-	{
-	    if (S_ISBLK (de->mode) && de->u.bdev.removable) break;
-	}
-	devfs_get (de);
-    }
-    read_unlock (&dir->u.dir.lock);
-    if (de) check_disc_changed (de);
-    devfs_put (de);
-}   /*  End Function scan_dir_for_removable  */
-
-/**
- *	get_removable_partition - Get removable media partition.
- *	@dir: The parent directory.
- *	@name: The name of the entry.
- *	@namelen: The number of characters in <<name>>.
- *
- *	Returns 1 if the media was changed, else 0.
- *
- *	This function may block, and may indirectly cause the directory
- *	contents to be changed due to partition re-reading. The directory must
- *	be locked for reading upon entry, and will be unlocked upon exit.
- */
-
-static int get_removable_partition (struct devfs_entry *dir, const char *name,
-				    unsigned int namelen)
-{
-    int retval;
-    struct devfs_entry *de;
-
-    if (dir->u.dir.num_removable < 1)
-    {
-	read_unlock (&dir->u.dir.lock);
-	return 0;
-    }
-    for (de = dir->u.dir.first; de != NULL; de = de->next)
-    {
-	if (!S_ISBLK (de->mode) || !de->u.bdev.removable) continue;
-	if (strcmp (de->name, "disc") == 0) break;
-	/*  Support for names where the partition is appended to the disc name
-	 */
-	if (de->namelen >= namelen) continue;
-	if (strncmp (de->name, name, de->namelen) == 0) break;
-    }
-    devfs_get (de);
-    read_unlock (&dir->u.dir.lock);
-    retval = de ? check_disc_changed (de) : 0;
-    devfs_put (de);
-    return retval;
-}   /*  End Function get_removable_partition  */
-
-
 /*  Superblock operations follow  */
 
 static struct inode_operations devfs_iops;
@@ -2169,7 +2066,6 @@ static int devfs_readdir (struct file *file, void *dirent, filldir_t filldir)
     switch ( (long) file->f_pos )
     {
       case 0:
-	scan_dir_for_removable (parent);
 	err = (*filldir) (dirent, "..", 2, file->f_pos,
 			  parent_ino (file->f_dentry), DT_DIR);
 	if (err == -EINVAL) break;
@@ -2410,18 +2306,7 @@ static struct dentry *devfs_lookup (struct inode *dir, struct dentry *dentry)
     if (parent == NULL) return ERR_PTR (-ENOENT);
     read_lock (&parent->u.dir.lock);
     de = _devfs_search_dir (parent, dentry->d_name.name, dentry->d_name.len);
-    if (de) read_unlock (&parent->u.dir.lock);
-    else
-    {   /*  Try re-reading the partition (media may have changed)  */
-	if ( get_removable_partition (parent, dentry->d_name.name,
-				      dentry->d_name.len) )  /*  Unlocks  */
-	{   /*  Media did change  */
-	    read_lock (&parent->u.dir.lock);
-	    de = _devfs_search_dir (parent, dentry->d_name.name,
-				    dentry->d_name.len);
     read_unlock (&parent->u.dir.lock);
-	}
-    }
     lookup_info.de = de;
     init_waitqueue_head (&lookup_info.wait_queue);
     dentry->d_fsdata = &lookup_info;
@@ -2548,7 +2433,7 @@ static int devfs_mkdir (struct inode *dir, struct dentry *dentry, int mode)
     de = _devfs_alloc_entry (dentry->d_name.name, dentry->d_name.len, mode);
     if (!de) return -ENOMEM;
     de->vfs_deletable = TRUE;
-    if ( ( err = _devfs_append_entry (parent, de, FALSE, NULL) ) != 0 )
+    if ( ( err = _devfs_append_entry (parent, de, NULL) ) != 0 )
 	return err;
     de->inode.uid = current->euid;
     de->inode.gid = current->egid;
@@ -2616,7 +2501,7 @@ static int devfs_mknod (struct inode *dir, struct dentry *dentry, int mode,
 	de->u.cdev.dev = rdev;
     else if (S_ISBLK (mode))
 	de->u.bdev.dev = rdev;
-    if ( ( err = _devfs_append_entry (parent, de, FALSE, NULL) ) != 0 )
+    if ( ( err = _devfs_append_entry (parent, de, NULL) ) != 0 )
 	return err;
     de->inode.uid = current->euid;
     de->inode.gid = current->egid;

fs/partitions/check.c

@@ -160,7 +160,6 @@ static void devfs_register_partition(struct gendisk *dev, int part)
 {
 #ifdef CONFIG_DEVFS_FS
 	devfs_handle_t dir;
-	unsigned int devfs_flags = DEVFS_FL_DEFAULT;
 	struct hd_struct *p = dev->part;
 	char devname[16];
 
@@ -169,10 +168,8 @@ static void devfs_register_partition(struct gendisk *dev, int part)
 	dir = dev->de;
 	if (!dir)
 		return;
-	if (dev->flags & GENHD_FL_REMOVABLE)
-		devfs_flags |= DEVFS_FL_REMOVABLE;
 	sprintf(devname, "part%d", part);
-	p[part-1].de = devfs_register (dir, devname, devfs_flags,
+	p[part-1].de = devfs_register (dir, devname, 0,
 				    dev->major, dev->first_minor + part,
 				    S_IFBLK | S_IRUSR | S_IWUSR,
 				    dev->fops, NULL);
@@ -189,11 +186,8 @@ static void devfs_create_partitions(struct gendisk *dev)
 #ifdef CONFIG_DEVFS_FS
 	int pos = 0;
 	devfs_handle_t dir, slave;
-	unsigned int devfs_flags = DEVFS_FL_DEFAULT;
 	char dirname[64], symlink[16];
 
-	if (dev->flags & GENHD_FL_REMOVABLE)
-		devfs_flags |= DEVFS_FL_REMOVABLE;
 	if (dev->flags & GENHD_FL_DEVFS) {
 		dir = dev->de;
 		if (!dir)  /*  Aware driver wants to block disc management  */
@@ -213,7 +207,7 @@ static void devfs_create_partitions(struct gendisk *dev)
 	sprintf(symlink, "discs/disc%d", dev->number);
 	devfs_mk_symlink(NULL, symlink, DEVFS_FL_DEFAULT,
 			  dirname + pos, &slave, NULL);
-	dev->disk_de = devfs_register(dir, "disc", devfs_flags,
+	dev->disk_de = devfs_register(dir, "disc", 0,
 			    dev->major, dev->first_minor,
 			    S_IFBLK | S_IRUSR | S_IWUSR, dev->fops, NULL);
 #endif

include/linux/devfs_fs_kernel.h

@@ -13,7 +13,6 @@
 
 #define DEVFS_FL_NONE           0x000 /* This helps to make code more readable
 				       */
-#define DEVFS_FL_REMOVABLE      0x008 /* This is a removable media device    */
 #define DEVFS_FL_WAIT           0x010 /* Wait for devfsd to finish           */
 #define DEVFS_FL_CURRENT_OWNER  0x020 /* Set initial ownership to current    */
 #define DEVFS_FL_DEFAULT        DEVFS_FL_NONE