Merge bk://bkbits.ras.ucalgary.ca/rgooch-2.5v2.5.16

into home.transmeta.com:/home/torvalds/v2.5/linux

4 files changed, 108 insertions, 59 deletions

diff --git a/Documentation/filesystems/devfs/ChangeLog b/Documentation/filesystems/devfs/ChangeLog
index 4c4ddd9d2758c..1db800e739c77 100644
--- a/Documentation/filesystems/devfs/ChangeLog
+++ b/Documentation/filesystems/devfs/ChangeLog
@@ -1912,3 +1912,22 @@ Changes for patch v210
   Thanks to Anton Blanchard <anton@samba.org>
 
 - Updated README from master HTML file
+===============================================================================
+Changes for patch v211
+
+- Do not put miscellaneous character devices in /dev/misc if they
+  specify their own directory (i.e. contain a '/' character)
+
+- Copied macro for error messages from fs/devfs/base.c to
+  fs/devfs/util.c and made use of this macro
+
+- Removed 2.4.x compatibility code from fs/devfs/base.c
+===============================================================================
+Changes for patch v212
+
+- Added BKL to <devfs_open> because drivers still need it
+===============================================================================
+Changes for patch v213
+
+- Protected <scan_dir_for_removable> and <get_removable_partition>
+  from changing directory contents
diff --git a/drivers/char/misc.c b/drivers/char/misc.c
index bb45e919fc01e..e410c4a65a79b 100644
--- a/drivers/char/misc.c
+++ b/drivers/char/misc.c
@@ -170,7 +170,7 @@ static struct file_operations misc_fops = {
  
 int misc_register(struct miscdevice * misc)
 {
-	static devfs_handle_t devfs_handle;
+	static devfs_handle_t devfs_handle, dir;
 	struct miscdevice *c;
 	
 	if (misc->next || misc->prev)
@@ -201,11 +201,12 @@ int misc_register(struct miscdevice * misc)
 		misc_minors[misc->minor >> 3] |= 1 << (misc->minor & 7);
 	if (!devfs_handle)
 		devfs_handle = devfs_mk_dir (NULL, "misc", NULL);
+	dir = strchr (misc->name, '/') ? NULL : devfs_handle;
 	misc->devfs_handle =
-	    devfs_register (devfs_handle, misc->name, DEVFS_FL_NONE,
-			    MISC_MAJOR, misc->minor,
-			    S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP,
-			    misc->fops, NULL);
+		devfs_register (dir, misc->name, DEVFS_FL_NONE,
+				MISC_MAJOR, misc->minor,
+				S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP,
+				misc->fops, NULL);
 
 	/*
 	 * Add it to the front, so that later devices can "override"
diff --git a/fs/devfs/base.c b/fs/devfs/base.c
index 862f7486cc959..f6d4c7125ebfd 100644
--- a/fs/devfs/base.c
+++ b/fs/devfs/base.c
@@ -620,6 +620,19 @@
 	       unlock_kernel() due to recent VFS locking changes. BKL isn't
 	       required in devfs.
   v1.13
+    20020428   Richard Gooch <rgooch@atnf.csiro.au>
+	       Removed 2.4.x compatibility code.
+  v1.14
+    20020510   Richard Gooch <rgooch@atnf.csiro.au>
+	       Added BKL to <devfs_open> because drivers still need it.
+  v1.15
+    20020512   Richard Gooch <rgooch@atnf.csiro.au>
+	       Protected <scan_dir_for_removable> and <get_removable_partition>
+	       from changing directory contents.
+  v1.16
+    20020514   Richard Gooch <rgooch@atnf.csiro.au>
+	       Minor cleanup of <scan_dir_for_removable>.
+  v1.17
 */
 #include <linux/types.h>
 #include <linux/errno.h>
@@ -652,7 +665,7 @@
 #include <asm/bitops.h>
 #include <asm/atomic.h>
 
-#define DEVFS_VERSION            "1.13 (20020406)"
+#define DEVFS_VERSION            "1.17 (20020514)"
 
 #define DEVFS_NAME "devfs"
 
@@ -1400,16 +1413,8 @@ static void free_dentry (struct devfs_entry *de)
 
 static int is_devfsd_or_child (struct fs_info *fs_info)
 {
-    struct task_struct *p;
-
     if (current == fs_info->devfsd_task) return (TRUE);
     if (current->pgrp == fs_info->devfsd_pgrp) return (TRUE);
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,1)
-    for (p = current->p_opptr; p != &init_task; p = p->p_opptr)
-    {
-	if (p == fs_info->devfsd_task) return (TRUE);
-    }
-#endif
     return (FALSE);
 }   /*  End Function is_devfsd_or_child  */
 
@@ -1829,16 +1834,6 @@ devfs_handle_t devfs_mk_dir (devfs_handle_t dir, const char *name, void *info)
     de->info = info;
     if ( ( err = _devfs_append_entry (dir, de, FALSE, &old) ) != 0 )
     {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,1)
-	if ( old && S_ISDIR (old->mode) )
-	{
-	    PRINTK ("(%s): using old entry in dir: %p \"%s\"\n",
-		    name, dir, dir->name);
-	    old->vfs_deletable = FALSE;
-	    devfs_put (dir);
-	    return old;
-	}
-#endif
 	PRINTK ("(%s): could not append to dir: %p \"%s\", err: %d\n",
 		name, dir, dir->name, err);
 	devfs_put (old);
@@ -2427,6 +2422,9 @@ static int try_modload (struct devfs_entry *parent, struct fs_info *fs_info,
  *	@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)
@@ -2461,19 +2459,29 @@ out:
 /**
  *	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;
 
-    if (dir->u.dir.num_removable < 1) return;
-    for (de = dir->u.dir.first; de != NULL; de = de->next)
+    read_lock (&dir->u.dir.lock);
+    if (dir->u.dir.num_removable < 1) de = NULL;
+    else
     {
-	if ( !S_ISBLK (de->mode) ) continue;
-	if (!de->u.fcb.removable) continue;
-	check_disc_changed (de);
+	for (de = dir->u.dir.first; de != NULL; de = de->next)
+	{
+	    if (S_ISBLK (de->mode) && de->u.fcb.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  */
 
 /**
@@ -2483,25 +2491,37 @@ static void scan_dir_for_removable (struct devfs_entry *dir)
  *	@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) ) continue;
-	if (!de->u.fcb.removable) continue;
-	if (strcmp (de->name, "disc") == 0) return check_disc_changed (de);
+	if (!S_ISBLK (de->mode) || !de->u.fcb.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) continue;
-	return check_disc_changed (de);
+	if (strncmp (de->name, name, de->namelen) == 0) break;
     }
-    return 0;
+    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  */
 
 
@@ -2739,15 +2759,22 @@ static int devfs_open (struct inode *inode, struct file *file)
     {
 	file->f_op = &def_blk_fops;
 	if (df->ops) inode->i_bdev->bd_op = df->ops;
+	err = def_blk_fops.open (inode, file);
     }
-    else file->f_op = fops_get ( (struct file_operations *) df->ops );
-    if (file->f_op)
-	err = file->f_op->open ? (*file->f_op->open) (inode, file) : 0;
     else
     {
-	/*  Fallback to legacy scheme  */
-	if ( S_ISCHR (inode->i_mode) ) err = chrdev_open (inode, file);
-	else err = -ENODEV;
+	file->f_op = fops_get ( (struct file_operations *) df->ops );
+	if (file->f_op)
+	{
+	    lock_kernel ();
+	    err = file->f_op->open ? (*file->f_op->open) (inode, file) : 0;
+	    unlock_kernel ();
+	}
+	else
+	{   /*  Fallback to legacy scheme  */
+	    if ( S_ISCHR (inode->i_mode) ) err = chrdev_open (inode, file);
+	    else err = -ENODEV;
+	}
     }
     if (err < 0) return err;
     /*  Open was successful  */
@@ -2947,15 +2974,17 @@ 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);
-    read_unlock (&parent->u.dir.lock);
-    if ( (de == NULL) && (parent->u.dir.num_removable > 0) &&
-	 get_removable_partition (parent, dentry->d_name.name,
-				  dentry->d_name.len) )
-    {
-	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);
+    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);
diff --git a/fs/devfs/util.c b/fs/devfs/util.c
index f9c955f6b61c3..9431e7d903b2b 100644
--- a/fs/devfs/util.c
+++ b/fs/devfs/util.c
@@ -56,6 +56,8 @@
                Made major bitfield type and initialiser 64 bit safe.
     20020413   Richard Gooch <rgooch@atnf.csiro.au>
                Fixed shift warning on 64 bit machines.
+    20020428   Richard Gooch <rgooch@atnf.csiro.au>
+               Copied and used macro for error messages from fs/devfs/base.c 
 */
 #include <linux/module.h>
 #include <linux/init.h>
@@ -65,6 +67,9 @@
 
 #include <asm/bitops.h>
 
+#define PRINTK(format, args...) \
+   {printk (KERN_ERR "%s" format, __FUNCTION__ , ## args);}
+
 
 /*  Private functions follow  */
 
@@ -209,9 +214,7 @@ void devfs_dealloc_major (char type, int major)
     spin_lock (&list->lock);
     was_set = __test_and_clear_bit (major, list->bits);
     spin_unlock (&list->lock);
-    if (!was_set)
-	printk (KERN_ERR __FUNCTION__ "(): major %d was already free\n",
-		major);
+    if (!was_set) PRINTK ("(): major %d was already free\n", major);
 }   /*  End Function devfs_dealloc_major  */
 EXPORT_SYMBOL(devfs_dealloc_major);
 
@@ -339,12 +342,11 @@ void devfs_dealloc_devnum (char type, kdev_t devnum)
 	if (was_set) list->none_free = 0;
 	up (semaphore);
 	if (!was_set)
-	    printk ( KERN_ERR __FUNCTION__ "(): device %s was already free\n",
-		     kdevname (devnum) );
+	    PRINTK ( "(): device %s was already free\n", kdevname (devnum) );
 	return;
     }
     up (semaphore);
-    printk ( KERN_ERR __FUNCTION__ "(): major for %s not previously allocated\n",
+    PRINTK ( "(): major for %s not previously allocated\n",
 	     kdevname (devnum) );
 }   /*  End Function devfs_dealloc_devnum  */
 EXPORT_SYMBOL(devfs_dealloc_devnum);
@@ -419,8 +421,6 @@ void devfs_dealloc_unique_number (struct unique_numspace *space, int number)
     was_set = __test_and_clear_bit (number, space->bits);
     if (was_set) ++space->num_free;
     up (&space->semaphore);
-    if (!was_set)
-	printk (KERN_ERR __FUNCTION__ "(): number %d was already free\n",
-		number);
+    if (!was_set) PRINTK ("(): number %d was already free\n", number);
 }   /*  End Function devfs_dealloc_unique_number  */
 EXPORT_SYMBOL(devfs_dealloc_unique_number);