Merge to Fedora kernel-2.6.18-1.2224_FC5 patched with stable patch-2.6.18.1-vs2.0...

[linux-2.6.git] / fs / block_dev.c

diff --git a/fs/block_dev.c b/fs/block_dev.c
index f5958f4..73648d8 100644 (file)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -5,14 +5,12 @@
  *  Copyright (C) 2001  Andrea Arcangeli <andrea@suse.de> SuSE
  */
 
-#include <linux/config.h>
 #include <linux/init.h>
 #include <linux/mm.h>
 #include <linux/fcntl.h>
 #include <linux/slab.h>
 #include <linux/kmod.h>
 #include <linux/major.h>
-#include <linux/devfs_fs_kernel.h>
 #include <linux/smp_lock.h>
 #include <linux/highmem.h>
 #include <linux/blkdev.h>
@@ -262,7 +260,6 @@ static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
            SLAB_CTOR_CONSTRUCTOR)
        {
                memset(bdev, 0, sizeof(*bdev));
-               mutex_init(&bdev->bd_mutex);
                mutex_init(&bdev->bd_mount_mutex);
                INIT_LIST_HEAD(&bdev->bd_inodes);
                INIT_LIST_HEAD(&bdev->bd_list);
@@ -300,10 +297,10 @@ static struct super_operations bdev_sops = {
        .clear_inode = bdev_clear_inode,
 };
 
-static struct super_block *bd_get_sb(struct file_system_type *fs_type,
-       int flags, const char *dev_name, void *data)
+static int bd_get_sb(struct file_system_type *fs_type,
+       int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 {
-       return get_sb_pseudo(fs_type, "bdev:", &bdev_sops, 0x62646576);
+       return get_sb_pseudo(fs_type, "bdev:", &bdev_sops, 0x62646576, mnt);
 }
 
 static struct file_system_type bd_type = {
@@ -355,10 +352,14 @@ static int bdev_set(struct inode *inode, void *data)
 
 static LIST_HEAD(all_bdevs);
 
+static struct lock_class_key bdev_part_lock_key;
+
 struct block_device *bdget(dev_t dev)
 {
        struct block_device *bdev;
        struct inode *inode;
+       struct gendisk *disk;
+       int part = 0;
 
        inode = iget5_locked(bd_mnt->mnt_sb, hash(dev),
                        bdev_test, bdev_set, &dev);
@@ -384,6 +385,11 @@ struct block_device *bdget(dev_t dev)
                list_add(&bdev->bd_list, &all_bdevs);
                spin_unlock(&bdev_lock);
                unlock_new_inode(inode);
+               mutex_init(&bdev->bd_mutex);
+               disk = get_gendisk(dev, &part);
+               if (disk && part)
+                       lockdep_set_class(&bdev->bd_mutex, &bdev_part_lock_key);
+               put_disk(disk);
        }
        return bdev;
 }
@@ -414,21 +420,31 @@ EXPORT_SYMBOL(bdput);
 static struct block_device *bd_acquire(struct inode *inode)
 {
        struct block_device *bdev;
+
        spin_lock(&bdev_lock);
        bdev = inode->i_bdev;
-       if (bdev && igrab(bdev->bd_inode)) {
+       if (bdev) {
+               atomic_inc(&bdev->bd_inode->i_count);
                spin_unlock(&bdev_lock);
                return bdev;
        }
        spin_unlock(&bdev_lock);
+
        bdev = bdget(inode->i_rdev);
        if (bdev) {
                spin_lock(&bdev_lock);
-               if (inode->i_bdev)
-                       __bd_forget(inode);
-               inode->i_bdev = bdev;
-               inode->i_mapping = bdev->bd_inode->i_mapping;
-               list_add(&inode->i_devices, &bdev->bd_inodes);
+               if (!inode->i_bdev) {
+                       /*
+                        * We take an additional bd_inode->i_count for inode,
+                        * and it's released in clear_inode() of inode.
+                        * So, we can access it via ->i_mapping always
+                        * without igrab().
+                        */
+                       atomic_inc(&bdev->bd_inode->i_count);
+                       inode->i_bdev = bdev;
+                       inode->i_mapping = bdev->bd_inode->i_mapping;
+                       list_add(&inode->i_devices, &bdev->bd_inodes);
+               }
                spin_unlock(&bdev_lock);
        }
        return bdev;
@@ -438,10 +454,18 @@ static struct block_device *bd_acquire(struct inode *inode)
 
 void bd_forget(struct inode *inode)
 {
+       struct block_device *bdev = NULL;
+
        spin_lock(&bdev_lock);
-       if (inode->i_bdev)
+       if (inode->i_bdev) {
+               if (inode->i_sb != blockdev_superblock)
+                       bdev = inode->i_bdev;
                __bd_forget(inode);
+       }
        spin_unlock(&bdev_lock);
+
+       if (bdev)
+               iput(bdev->bd_inode);
 }
 
 int bd_claim(struct block_device *bdev, void *holder)
@@ -1077,7 +1101,7 @@ static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
        return blkdev_ioctl(file->f_mapping->host, file, cmd, arg);
 }
 
-struct address_space_operations def_blk_aops = {
+const struct address_space_operations def_blk_aops = {
        .readpage       = blkdev_readpage,
        .writepage      = blkdev_writepage,
        .sync_page      = block_sync_page,