ocfs2: set gap to seperate entry and value when xattr in bucket
[safe/jmp/linux-2.6] / fs / block_dev.c
index ddb305e..b3c1eff 100644 (file)
@@ -5,7 +5,6 @@
  *  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/kmod.h>
 #include <linux/major.h>
 #include <linux/smp_lock.h>
+#include <linux/device_cgroup.h>
 #include <linux/highmem.h>
 #include <linux/blkdev.h>
 #include <linux/module.h>
 #include <linux/blkpg.h>
 #include <linux/buffer_head.h>
+#include <linux/writeback.h>
 #include <linux/mpage.h>
 #include <linux/mount.h>
 #include <linux/uio.h>
 #include <linux/namei.h>
+#include <linux/log2.h>
 #include <asm/uaccess.h>
+#include "internal.h"
 
 struct bdev_inode {
        struct block_device bdev;
        struct inode vfs_inode;
 };
 
+static const struct address_space_operations def_blk_aops;
+
 static inline struct bdev_inode *BDEV_I(struct inode *inode)
 {
        return container_of(inode, struct bdev_inode, vfs_inode);
@@ -54,17 +59,19 @@ static sector_t max_block(struct block_device *bdev)
        return retval;
 }
 
-/* Kill _all_ buffers, dirty or not.. */
+/* Kill _all_ buffers and pagecache , dirty or not.. */
 static void kill_bdev(struct block_device *bdev)
 {
-       invalidate_bdev(bdev, 1);
+       if (bdev->bd_inode->i_mapping->nrpages == 0)
+               return;
+       invalidate_bh_lrus();
        truncate_inode_pages(bdev->bd_inode->i_mapping, 0);
 }      
 
 int set_blocksize(struct block_device *bdev, int size)
 {
        /* Size must be a power of two, and between 512 and PAGE_SIZE */
-       if (size > PAGE_SIZE || size < 512 || (size & (size-1)))
+       if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size))
                return -EINVAL;
 
        /* Size cannot be smaller than the size supported by the device */
@@ -177,19 +184,31 @@ static int blkdev_readpage(struct file * file, struct page * page)
        return block_read_full_page(page, blkdev_get_block);
 }
 
-static int blkdev_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to)
+static int blkdev_write_begin(struct file *file, struct address_space *mapping,
+                       loff_t pos, unsigned len, unsigned flags,
+                       struct page **pagep, void **fsdata)
 {
-       return block_prepare_write(page, from, to, blkdev_get_block);
+       *pagep = NULL;
+       return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+                               blkdev_get_block);
 }
 
-static int blkdev_commit_write(struct file *file, struct page *page, unsigned from, unsigned to)
+static int blkdev_write_end(struct file *file, struct address_space *mapping,
+                       loff_t pos, unsigned len, unsigned copied,
+                       struct page *page, void *fsdata)
 {
-       return block_commit_write(page, from, to);
+       int ret;
+       ret = block_write_end(file, mapping, pos, len, copied, page, fsdata);
+
+       unlock_page(page);
+       page_cache_release(page);
+
+       return ret;
 }
 
 /*
  * private llseek:
- * for a block special file file->f_dentry->d_inode->i_size is zero
+ * for a block special file file->f_path.dentry->d_inode->i_size is zero
  * so we compute the size by hand (just as in block_read/write above)
  */
 static loff_t block_llseek(struct file *file, loff_t offset, int origin)
@@ -234,11 +253,11 @@ static int block_fsync(struct file *filp, struct dentry *dentry, int datasync)
  */
 
 static  __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock);
-static kmem_cache_t * bdev_cachep __read_mostly;
+static struct kmem_cache * bdev_cachep __read_mostly;
 
 static struct inode *bdev_alloc_inode(struct super_block *sb)
 {
-       struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, SLAB_KERNEL);
+       struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL);
        if (!ei)
                return NULL;
        return &ei->vfs_inode;
@@ -252,24 +271,22 @@ static void bdev_destroy_inode(struct inode *inode)
        kmem_cache_free(bdev_cachep, bdi);
 }
 
-static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
+static void init_once(void *foo)
 {
        struct bdev_inode *ei = (struct bdev_inode *) foo;
        struct block_device *bdev = &ei->bdev;
 
-       if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
-           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);
+       memset(bdev, 0, sizeof(*bdev));
+       mutex_init(&bdev->bd_mutex);
+       sema_init(&bdev->bd_mount_sem, 1);
+       INIT_LIST_HEAD(&bdev->bd_inodes);
+       INIT_LIST_HEAD(&bdev->bd_list);
 #ifdef CONFIG_SYSFS
-               INIT_LIST_HEAD(&bdev->bd_holder_list);
+       INIT_LIST_HEAD(&bdev->bd_holder_list);
 #endif
-               inode_init_once(&ei->vfs_inode);
-       }
+       inode_init_once(&ei->vfs_inode);
+       /* Initialize mutex for freeze. */
+       mutex_init(&bdev->bd_fsfreeze_mutex);
 }
 
 static inline void __bd_forget(struct inode *inode)
@@ -291,7 +308,7 @@ static void bdev_clear_inode(struct inode *inode)
        spin_unlock(&bdev_lock);
 }
 
-static struct super_operations bdev_sops = {
+static const struct super_operations bdev_sops = {
        .statfs = simple_statfs,
        .alloc_inode = bdev_alloc_inode,
        .destroy_inode = bdev_destroy_inode,
@@ -311,21 +328,21 @@ static struct file_system_type bd_type = {
        .kill_sb        = kill_anon_super,
 };
 
-static struct vfsmount *bd_mnt __read_mostly;
-struct super_block *blockdev_superblock;
+struct super_block *blockdev_superblock __read_mostly;
 
 void __init bdev_cache_init(void)
 {
        int err;
+       struct vfsmount *bd_mnt;
+
        bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode),
                        0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
                                SLAB_MEM_SPREAD|SLAB_PANIC),
-                       init_once, NULL);
+                       init_once);
        err = register_filesystem(&bd_type);
        if (err)
                panic("Cannot register bdev pseudo-fs");
        bd_mnt = kern_mount(&bd_type);
-       err = PTR_ERR(bd_mnt);
        if (IS_ERR(bd_mnt))
                panic("Cannot create bdev pseudo-fs");
        blockdev_superblock = bd_mnt->mnt_sb;   /* For writeback */
@@ -359,7 +376,7 @@ struct block_device *bdget(dev_t dev)
        struct block_device *bdev;
        struct inode *inode;
 
-       inode = iget5_locked(bd_mnt->mnt_sb, hash(dev),
+       inode = iget5_locked(blockdev_superblock, hash(dev),
                        bdev_test, bdev_set, &dev);
 
        if (!inode)
@@ -391,12 +408,10 @@ EXPORT_SYMBOL(bdget);
 
 long nr_blockdev_pages(void)
 {
-       struct list_head *p;
+       struct block_device *bdev;
        long ret = 0;
        spin_lock(&bdev_lock);
-       list_for_each(p, &all_bdevs) {
-               struct block_device *bdev;
-               bdev = list_entry(p, struct block_device, bd_list);
+       list_for_each_entry(bdev, &all_bdevs, bd_list) {
                ret += bdev->bd_inode->i_mapping->nrpages;
        }
        spin_unlock(&bdev_lock);
@@ -451,7 +466,7 @@ void bd_forget(struct inode *inode)
 
        spin_lock(&bdev_lock);
        if (inode->i_bdev) {
-               if (inode->i_sb != blockdev_superblock)
+               if (!sb_is_blkdev_sb(inode->i_sb))
                        bdev = inode->i_bdev;
                __bd_forget(inode);
        }
@@ -528,27 +543,11 @@ EXPORT_SYMBOL(bd_release);
  *           /sys/block/sda/holders/dm-0 --> /sys/block/dm-0
  */
 
-static struct kobject *bdev_get_kobj(struct block_device *bdev)
-{
-       if (bdev->bd_contains != bdev)
-               return kobject_get(&bdev->bd_part->kobj);
-       else
-               return kobject_get(&bdev->bd_disk->kobj);
-}
-
-static struct kobject *bdev_get_holder(struct block_device *bdev)
-{
-       if (bdev->bd_contains != bdev)
-               return kobject_get(bdev->bd_part->holder_dir);
-       else
-               return kobject_get(bdev->bd_disk->holder_dir);
-}
-
-static void add_symlink(struct kobject *from, struct kobject *to)
+static int add_symlink(struct kobject *from, struct kobject *to)
 {
        if (!from || !to)
-               return;
-       sysfs_create_link(from, to, kobject_name(to));
+               return 0;
+       return sysfs_create_link(from, to, kobject_name(to));
 }
 
 static void del_symlink(struct kobject *from, struct kobject *to)
@@ -592,11 +591,11 @@ static int bd_holder_grab_dirs(struct block_device *bdev,
        if (!bo->hdev)
                goto fail_put_sdir;
 
-       bo->sdev = bdev_get_kobj(bdev);
+       bo->sdev = kobject_get(&part_to_dev(bdev->bd_part)->kobj);
        if (!bo->sdev)
                goto fail_put_hdev;
 
-       bo->hdir = bdev_get_holder(bdev);
+       bo->hdir = kobject_get(bdev->bd_part->holder_dir);
        if (!bo->hdir)
                goto fail_put_sdev;
 
@@ -641,38 +640,62 @@ static void free_bd_holder(struct bd_holder *bo)
 }
 
 /**
+ * find_bd_holder - find matching struct bd_holder from the block device
+ *
+ * @bdev:      struct block device to be searched
+ * @bo:                target struct bd_holder
+ *
+ * Returns matching entry with @bo in @bdev->bd_holder_list.
+ * If found, increment the reference count and return the pointer.
+ * If not found, returns NULL.
+ */
+static struct bd_holder *find_bd_holder(struct block_device *bdev,
+                                       struct bd_holder *bo)
+{
+       struct bd_holder *tmp;
+
+       list_for_each_entry(tmp, &bdev->bd_holder_list, list)
+               if (tmp->sdir == bo->sdir) {
+                       tmp->count++;
+                       return tmp;
+               }
+
+       return NULL;
+}
+
+/**
  * add_bd_holder - create sysfs symlinks for bd_claim() relationship
  *
  * @bdev:      block device to be bd_claimed
  * @bo:                preallocated and initialized by alloc_bd_holder()
  *
- * If there is no matching entry with @bo in @bdev->bd_holder_list,
- * add @bo to the list, create symlinks.
+ * Add @bo to @bdev->bd_holder_list, create symlinks.
  *
- * Returns 1 if @bo was added to the list.
- * Returns 0 if @bo wasn't used by any reason and should be freed.
+ * Returns 0 if symlinks are created.
+ * Returns -ve if something fails.
  */
 static int add_bd_holder(struct block_device *bdev, struct bd_holder *bo)
 {
-       struct bd_holder *tmp;
+       int err;
 
        if (!bo)
-               return 0;
-
-       list_for_each_entry(tmp, &bdev->bd_holder_list, list) {
-               if (tmp->sdir == bo->sdir) {
-                       tmp->count++;
-                       return 0;
-               }
-       }
+               return -EINVAL;
 
        if (!bd_holder_grab_dirs(bdev, bo))
-               return 0;
+               return -EBUSY;
+
+       err = add_symlink(bo->sdir, bo->sdev);
+       if (err)
+               return err;
+
+       err = add_symlink(bo->hdir, bo->hdev);
+       if (err) {
+               del_symlink(bo->sdir, bo->sdev);
+               return err;
+       }
 
-       add_symlink(bo->sdir, bo->sdev);
-       add_symlink(bo->hdir, bo->hdev);
        list_add_tail(&bo->list, &bdev->bd_holder_list);
-       return 1;
+       return 0;
 }
 
 /**
@@ -730,8 +753,8 @@ static struct bd_holder *del_bd_holder(struct block_device *bdev,
 static int bd_claim_by_kobject(struct block_device *bdev, void *holder,
                                struct kobject *kobj)
 {
-       int res;
-       struct bd_holder *bo;
+       int err;
+       struct bd_holder *bo, *found;
 
        if (!kobj)
                return -EINVAL;
@@ -741,12 +764,24 @@ static int bd_claim_by_kobject(struct block_device *bdev, void *holder,
                return -ENOMEM;
 
        mutex_lock(&bdev->bd_mutex);
-       res = bd_claim(bdev, holder);
-       if (res || !add_bd_holder(bdev, bo))
-               free_bd_holder(bo);
-       mutex_unlock(&bdev->bd_mutex);
 
-       return res;
+       err = bd_claim(bdev, holder);
+       if (err)
+               goto fail;
+
+       found = find_bd_holder(bdev, bo);
+       if (found)
+               goto fail;
+
+       err = add_bd_holder(bdev, bo);
+       if (err)
+               bd_release(bdev);
+       else
+               bo = NULL;
+fail:
+       mutex_unlock(&bdev->bd_mutex);
+       free_bd_holder(bo);
+       return err;
 }
 
 /**
@@ -760,15 +795,12 @@ static int bd_claim_by_kobject(struct block_device *bdev, void *holder,
 static void bd_release_from_kobject(struct block_device *bdev,
                                        struct kobject *kobj)
 {
-       struct bd_holder *bo;
-
        if (!kobj)
                return;
 
        mutex_lock(&bdev->bd_mutex);
        bd_release(bdev);
-       if ((bo = del_bd_holder(bdev, kobj)))
-               free_bd_holder(bo);
+       free_bd_holder(del_bd_holder(bdev, kobj));
        mutex_unlock(&bdev->bd_mutex);
 }
 
@@ -811,18 +843,98 @@ EXPORT_SYMBOL_GPL(bd_release_from_disk);
  * to be used for internal purposes.  If you ever need it - reconsider
  * your API.
  */
-struct block_device *open_by_devnum(dev_t dev, unsigned mode)
+struct block_device *open_by_devnum(dev_t dev, fmode_t mode)
 {
        struct block_device *bdev = bdget(dev);
        int err = -ENOMEM;
-       int flags = mode & FMODE_WRITE ? O_RDWR : O_RDONLY;
        if (bdev)
-               err = blkdev_get(bdev, mode, flags);
+               err = blkdev_get(bdev, mode);
        return err ? ERR_PTR(err) : bdev;
 }
 
 EXPORT_SYMBOL(open_by_devnum);
 
+/**
+ * flush_disk - invalidates all buffer-cache entries on a disk
+ *
+ * @bdev:      struct block device to be flushed
+ *
+ * Invalidates all buffer-cache entries on a disk. It should be called
+ * when a disk has been changed -- either by a media change or online
+ * resize.
+ */
+static void flush_disk(struct block_device *bdev)
+{
+       if (__invalidate_device(bdev)) {
+               char name[BDEVNAME_SIZE] = "";
+
+               if (bdev->bd_disk)
+                       disk_name(bdev->bd_disk, 0, name);
+               printk(KERN_WARNING "VFS: busy inodes on changed media or "
+                      "resized disk %s\n", name);
+       }
+
+       if (!bdev->bd_disk)
+               return;
+       if (disk_partitionable(bdev->bd_disk))
+               bdev->bd_invalidated = 1;
+}
+
+/**
+ * check_disk_size_change - checks for disk size change and adjusts bdev size.
+ * @disk: struct gendisk to check
+ * @bdev: struct bdev to adjust.
+ *
+ * This routine checks to see if the bdev size does not match the disk size
+ * and adjusts it if it differs.
+ */
+void check_disk_size_change(struct gendisk *disk, struct block_device *bdev)
+{
+       loff_t disk_size, bdev_size;
+
+       disk_size = (loff_t)get_capacity(disk) << 9;
+       bdev_size = i_size_read(bdev->bd_inode);
+       if (disk_size != bdev_size) {
+               char name[BDEVNAME_SIZE];
+
+               disk_name(disk, 0, name);
+               printk(KERN_INFO
+                      "%s: detected capacity change from %lld to %lld\n",
+                      name, bdev_size, disk_size);
+               i_size_write(bdev->bd_inode, disk_size);
+               flush_disk(bdev);
+       }
+}
+EXPORT_SYMBOL(check_disk_size_change);
+
+/**
+ * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back
+ * @disk: struct gendisk to be revalidated
+ *
+ * This routine is a wrapper for lower-level driver's revalidate_disk
+ * call-backs.  It is used to do common pre and post operations needed
+ * for all revalidate_disk operations.
+ */
+int revalidate_disk(struct gendisk *disk)
+{
+       struct block_device *bdev;
+       int ret = 0;
+
+       if (disk->fops->revalidate_disk)
+               ret = disk->fops->revalidate_disk(disk);
+
+       bdev = bdget_disk(disk, 0);
+       if (!bdev)
+               return ret;
+
+       mutex_lock(&bdev->bd_mutex);
+       check_disk_size_change(disk, bdev);
+       mutex_unlock(&bdev->bd_mutex);
+       bdput(bdev);
+       return ret;
+}
+EXPORT_SYMBOL(revalidate_disk);
+
 /*
  * This routine checks whether a removable media has been changed,
  * and invalidates all buffer-cache-entries in that case. This
@@ -842,13 +954,9 @@ int check_disk_change(struct block_device *bdev)
        if (!bdops->media_changed(bdev->bd_disk))
                return 0;
 
-       if (__invalidate_device(bdev))
-               printk("VFS: busy inodes on changed media.\n");
-
+       flush_disk(bdev);
        if (bdops->revalidate_disk)
                bdops->revalidate_disk(bdev->bd_disk);
-       if (bdev->bd_disk->minors > 1)
-               bdev->bd_invalidated = 1;
        return 1;
 }
 
@@ -869,33 +977,72 @@ void bd_set_size(struct block_device *bdev, loff_t size)
 }
 EXPORT_SYMBOL(bd_set_size);
 
-static int do_open(struct block_device *bdev, struct file *file)
+static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part);
+
+/*
+ * bd_mutex locking:
+ *
+ *  mutex_lock(part->bd_mutex)
+ *    mutex_lock_nested(whole->bd_mutex, 1)
+ */
+
+static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 {
-       struct module *owner = NULL;
        struct gendisk *disk;
-       int ret = -ENXIO;
-       int part;
-
-       file->f_mapping = bdev->bd_inode->i_mapping;
-       lock_kernel();
-       disk = get_gendisk(bdev->bd_dev, &part);
-       if (!disk) {
-               unlock_kernel();
+       int ret;
+       int partno;
+       int perm = 0;
+
+       if (mode & FMODE_READ)
+               perm |= MAY_READ;
+       if (mode & FMODE_WRITE)
+               perm |= MAY_WRITE;
+       /*
+        * hooks: /n/, see "layering violations".
+        */
+       ret = devcgroup_inode_permission(bdev->bd_inode, perm);
+       if (ret != 0) {
                bdput(bdev);
                return ret;
        }
-       owner = disk->fops->owner;
 
-       mutex_lock(&bdev->bd_mutex);
+       lock_kernel();
+ restart:
+
+       ret = -ENXIO;
+       disk = get_gendisk(bdev->bd_dev, &partno);
+       if (!disk)
+               goto out_unlock_kernel;
+
+       mutex_lock_nested(&bdev->bd_mutex, for_part);
        if (!bdev->bd_openers) {
                bdev->bd_disk = disk;
                bdev->bd_contains = bdev;
-               if (!part) {
+               if (!partno) {
                        struct backing_dev_info *bdi;
+
+                       ret = -ENXIO;
+                       bdev->bd_part = disk_get_part(disk, partno);
+                       if (!bdev->bd_part)
+                               goto out_clear;
+
                        if (disk->fops->open) {
-                               ret = disk->fops->open(bdev->bd_inode, file);
+                               ret = disk->fops->open(bdev, mode);
+                               if (ret == -ERESTARTSYS) {
+                                       /* Lost a race with 'disk' being
+                                        * deleted, try again.
+                                        * See md.c
+                                        */
+                                       disk_put_part(bdev->bd_part);
+                                       bdev->bd_part = NULL;
+                                       module_put(disk->fops->owner);
+                                       put_disk(disk);
+                                       bdev->bd_disk = NULL;
+                                       mutex_unlock(&bdev->bd_mutex);
+                                       goto restart;
+                               }
                                if (ret)
-                                       goto out_first;
+                                       goto out_clear;
                        }
                        if (!bdev->bd_openers) {
                                bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
@@ -907,88 +1054,72 @@ static int do_open(struct block_device *bdev, struct file *file)
                        if (bdev->bd_invalidated)
                                rescan_partitions(disk, bdev);
                } else {
-                       struct hd_struct *p;
                        struct block_device *whole;
                        whole = bdget_disk(disk, 0);
                        ret = -ENOMEM;
                        if (!whole)
-                               goto out_first;
-                       ret = blkdev_get(whole, file->f_mode, file->f_flags);
+                               goto out_clear;
+                       BUG_ON(for_part);
+                       ret = __blkdev_get(whole, mode, 1);
                        if (ret)
-                               goto out_first;
+                               goto out_clear;
                        bdev->bd_contains = whole;
-                       mutex_lock(&whole->bd_mutex);
-                       whole->bd_part_count++;
-                       p = disk->part[part - 1];
                        bdev->bd_inode->i_data.backing_dev_info =
                           whole->bd_inode->i_data.backing_dev_info;
-                       if (!(disk->flags & GENHD_FL_UP) || !p || !p->nr_sects) {
-                               whole->bd_part_count--;
-                               mutex_unlock(&whole->bd_mutex);
+                       bdev->bd_part = disk_get_part(disk, partno);
+                       if (!(disk->flags & GENHD_FL_UP) ||
+                           !bdev->bd_part || !bdev->bd_part->nr_sects) {
                                ret = -ENXIO;
-                               goto out_first;
+                               goto out_clear;
                        }
-                       kobject_get(&p->kobj);
-                       bdev->bd_part = p;
-                       bd_set_size(bdev, (loff_t) p->nr_sects << 9);
-                       mutex_unlock(&whole->bd_mutex);
+                       bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
                }
        } else {
                put_disk(disk);
-               module_put(owner);
+               module_put(disk->fops->owner);
+               disk = NULL;
                if (bdev->bd_contains == bdev) {
                        if (bdev->bd_disk->fops->open) {
-                               ret = bdev->bd_disk->fops->open(bdev->bd_inode, file);
+                               ret = bdev->bd_disk->fops->open(bdev, mode);
                                if (ret)
-                                       goto out;
+                                       goto out_unlock_bdev;
                        }
                        if (bdev->bd_invalidated)
                                rescan_partitions(bdev->bd_disk, bdev);
-               } else {
-                       mutex_lock(&bdev->bd_contains->bd_mutex);
-                       bdev->bd_contains->bd_part_count++;
-                       mutex_unlock(&bdev->bd_contains->bd_mutex);
                }
        }
        bdev->bd_openers++;
+       if (for_part)
+               bdev->bd_part_count++;
        mutex_unlock(&bdev->bd_mutex);
        unlock_kernel();
        return 0;
 
-out_first:
+ out_clear:
+       disk_put_part(bdev->bd_part);
        bdev->bd_disk = NULL;
+       bdev->bd_part = NULL;
        bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
        if (bdev != bdev->bd_contains)
-               blkdev_put(bdev->bd_contains);
+               __blkdev_put(bdev->bd_contains, mode, 1);
        bdev->bd_contains = NULL;
-       put_disk(disk);
-       module_put(owner);
-out:
+ out_unlock_bdev:
        mutex_unlock(&bdev->bd_mutex);
+ out_unlock_kernel:
        unlock_kernel();
-       if (ret)
-               bdput(bdev);
+
+       if (disk)
+               module_put(disk->fops->owner);
+       put_disk(disk);
+       bdput(bdev);
+
        return ret;
 }
 
-int blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags)
+int blkdev_get(struct block_device *bdev, fmode_t mode)
 {
-       /*
-        * This crockload is due to bad choice of ->open() type.
-        * It will go away.
-        * For now, block device ->open() routine must _not_
-        * examine anything in 'inode' argument except ->i_rdev.
-        */
-       struct file fake_file = {};
-       struct dentry fake_dentry = {};
-       fake_file.f_mode = mode;
-       fake_file.f_flags = flags;
-       fake_file.f_dentry = &fake_dentry;
-       fake_dentry.d_inode = bdev->bd_inode;
-
-       return do_open(bdev, &fake_file);
+       return __blkdev_get(bdev, mode, 0);
 }
-
 EXPORT_SYMBOL(blkdev_get);
 
 static int blkdev_open(struct inode * inode, struct file * filp)
@@ -1004,65 +1135,80 @@ static int blkdev_open(struct inode * inode, struct file * filp)
         */
        filp->f_flags |= O_LARGEFILE;
 
+       if (filp->f_flags & O_NDELAY)
+               filp->f_mode |= FMODE_NDELAY;
+       if (filp->f_flags & O_EXCL)
+               filp->f_mode |= FMODE_EXCL;
+       if ((filp->f_flags & O_ACCMODE) == 3)
+               filp->f_mode |= FMODE_WRITE_IOCTL;
+
        bdev = bd_acquire(inode);
+       if (bdev == NULL)
+               return -ENOMEM;
+
+       filp->f_mapping = bdev->bd_inode->i_mapping;
 
-       res = do_open(bdev, filp);
+       res = blkdev_get(bdev, filp->f_mode);
        if (res)
                return res;
 
-       if (!(filp->f_flags & O_EXCL) )
-               return 0;
+       if (filp->f_mode & FMODE_EXCL) {
+               res = bd_claim(bdev, filp);
+               if (res)
+                       goto out_blkdev_put;
+       }
 
-       if (!(res = bd_claim(bdev, filp)))
-               return 0;
+       return 0;
 
-       blkdev_put(bdev);
+ out_blkdev_put:
+       blkdev_put(bdev, filp->f_mode);
        return res;
 }
 
-int blkdev_put(struct block_device *bdev)
+static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
 {
        int ret = 0;
-       struct inode *bd_inode = bdev->bd_inode;
        struct gendisk *disk = bdev->bd_disk;
+       struct block_device *victim = NULL;
 
-       mutex_lock(&bdev->bd_mutex);
+       mutex_lock_nested(&bdev->bd_mutex, for_part);
        lock_kernel();
+       if (for_part)
+               bdev->bd_part_count--;
+
        if (!--bdev->bd_openers) {
                sync_blockdev(bdev);
                kill_bdev(bdev);
        }
        if (bdev->bd_contains == bdev) {
                if (disk->fops->release)
-                       ret = disk->fops->release(bd_inode, NULL);
-       } else {
-               mutex_lock(&bdev->bd_contains->bd_mutex);
-               bdev->bd_contains->bd_part_count--;
-               mutex_unlock(&bdev->bd_contains->bd_mutex);
+                       ret = disk->fops->release(disk, mode);
        }
        if (!bdev->bd_openers) {
                struct module *owner = disk->fops->owner;
 
                put_disk(disk);
                module_put(owner);
-
-               if (bdev->bd_contains != bdev) {
-                       kobject_put(&bdev->bd_part->kobj);
-                       bdev->bd_part = NULL;
-               }
+               disk_put_part(bdev->bd_part);
+               bdev->bd_part = NULL;
                bdev->bd_disk = NULL;
                bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
-               if (bdev != bdev->bd_contains) {
-                       blkdev_put(bdev->bd_contains);
-               }
+               if (bdev != bdev->bd_contains)
+                       victim = bdev->bd_contains;
                bdev->bd_contains = NULL;
        }
        unlock_kernel();
        mutex_unlock(&bdev->bd_mutex);
        bdput(bdev);
+       if (victim)
+               __blkdev_put(victim, mode, 1);
        return ret;
 }
 
+int blkdev_put(struct block_device *bdev, fmode_t mode)
+{
+       return __blkdev_put(bdev, mode, 0);
+}
 EXPORT_SYMBOL(blkdev_put);
 
 static int blkdev_close(struct inode * inode, struct file * filp)
@@ -1070,37 +1216,48 @@ static int blkdev_close(struct inode * inode, struct file * filp)
        struct block_device *bdev = I_BDEV(filp->f_mapping->host);
        if (bdev->bd_holder == filp)
                bd_release(bdev);
-       return blkdev_put(bdev);
+       return blkdev_put(bdev, filp->f_mode);
 }
 
-static ssize_t blkdev_file_write(struct file *file, const char __user *buf,
-                                  size_t count, loff_t *ppos)
+static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 {
-       struct iovec local_iov = { .iov_base = (void __user *)buf, .iov_len = count };
+       struct block_device *bdev = I_BDEV(file->f_mapping->host);
+       fmode_t mode = file->f_mode;
+
+       /*
+        * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
+        * to updated it before every ioctl.
+        */
+       if (file->f_flags & O_NDELAY)
+               mode |= FMODE_NDELAY;
+       else
+               mode &= ~FMODE_NDELAY;
 
-       return generic_file_write_nolock(file, &local_iov, 1, ppos);
+       return blkdev_ioctl(bdev, mode, cmd, arg);
 }
 
-static ssize_t blkdev_file_aio_write(struct kiocb *iocb, const char __user *buf,
-                                  size_t count, loff_t pos)
+/*
+ * Try to release a page associated with block device when the system
+ * is under memory pressure.
+ */
+static int blkdev_releasepage(struct page *page, gfp_t wait)
 {
-       struct iovec local_iov = { .iov_base = (void __user *)buf, .iov_len = count };
+       struct super_block *super = BDEV_I(page->mapping->host)->bdev.bd_super;
 
-       return generic_file_aio_write_nolock(iocb, &local_iov, 1, &iocb->ki_pos);
-}
+       if (super && super->s_op->bdev_try_to_free_page)
+               return super->s_op->bdev_try_to_free_page(super, page, wait);
 
-static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
-{
-       return blkdev_ioctl(file->f_mapping->host, file, cmd, arg);
+       return try_to_free_buffers(page);
 }
 
-struct address_space_operations def_blk_aops = {
+static const struct address_space_operations def_blk_aops = {
        .readpage       = blkdev_readpage,
        .writepage      = blkdev_writepage,
        .sync_page      = block_sync_page,
-       .prepare_write  = blkdev_prepare_write,
-       .commit_write   = blkdev_commit_write,
+       .write_begin    = blkdev_write_begin,
+       .write_end      = blkdev_write_end,
        .writepages     = generic_writepages,
+       .releasepage    = blkdev_releasepage,
        .direct_IO      = blkdev_direct_IO,
 };
 
@@ -1108,19 +1265,16 @@ const struct file_operations def_blk_fops = {
        .open           = blkdev_open,
        .release        = blkdev_close,
        .llseek         = block_llseek,
-       .read           = generic_file_read,
-       .write          = blkdev_file_write,
+       .read           = do_sync_read,
+       .write          = do_sync_write,
        .aio_read       = generic_file_aio_read,
-       .aio_write      = blkdev_file_aio_write, 
+       .aio_write      = generic_file_aio_write_nolock,
        .mmap           = generic_file_mmap,
        .fsync          = block_fsync,
        .unlocked_ioctl = block_ioctl,
 #ifdef CONFIG_COMPAT
        .compat_ioctl   = compat_blkdev_ioctl,
 #endif
-       .readv          = generic_file_readv,
-       .writev         = generic_file_write_nolock,
-       .sendfile       = generic_file_sendfile,
        .splice_read    = generic_file_splice_read,
        .splice_write   = generic_file_splice_write,
 };
@@ -1130,7 +1284,7 @@ int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg)
        int res;
        mm_segment_t old_fs = get_fs();
        set_fs(KERNEL_DS);
-       res = blkdev_ioctl(bdev->bd_inode, NULL, cmd, arg);
+       res = blkdev_ioctl(bdev, 0, cmd, arg);
        set_fs(old_fs);
        return res;
 }
@@ -1139,73 +1293,70 @@ EXPORT_SYMBOL(ioctl_by_bdev);
 
 /**
  * lookup_bdev  - lookup a struct block_device by name
+ * @pathname:  special file representing the block device
  *
- * @path:      special file representing the block device
- *
- * Get a reference to the blockdevice at @path in the current
+ * Get a reference to the blockdevice at @pathname in the current
  * namespace if possible and return it.  Return ERR_PTR(error)
  * otherwise.
  */
-struct block_device *lookup_bdev(const char *path)
+struct block_device *lookup_bdev(const char *pathname)
 {
        struct block_device *bdev;
        struct inode *inode;
-       struct nameidata nd;
+       struct path path;
        int error;
 
-       if (!path || !*path)
+       if (!pathname || !*pathname)
                return ERR_PTR(-EINVAL);
 
-       error = path_lookup(path, LOOKUP_FOLLOW, &nd);
+       error = kern_path(pathname, LOOKUP_FOLLOW, &path);
        if (error)
                return ERR_PTR(error);
 
-       inode = nd.dentry->d_inode;
+       inode = path.dentry->d_inode;
        error = -ENOTBLK;
        if (!S_ISBLK(inode->i_mode))
                goto fail;
        error = -EACCES;
-       if (nd.mnt->mnt_flags & MNT_NODEV)
+       if (path.mnt->mnt_flags & MNT_NODEV)
                goto fail;
        error = -ENOMEM;
        bdev = bd_acquire(inode);
        if (!bdev)
                goto fail;
 out:
-       path_release(&nd);
+       path_put(&path);
        return bdev;
 fail:
        bdev = ERR_PTR(error);
        goto out;
 }
+EXPORT_SYMBOL(lookup_bdev);
 
 /**
- * open_bdev_excl  -  open a block device by name and set it up for use
+ * open_bdev_exclusive  -  open a block device by name and set it up for use
  *
  * @path:      special file representing the block device
- * @flags:     %MS_RDONLY for opening read-only
+ * @mode:      FMODE_... combination to pass be used
  * @holder:    owner for exclusion
  *
  * Open the blockdevice described by the special file at @path, claim it
  * for the @holder.
  */
-struct block_device *open_bdev_excl(const char *path, int flags, void *holder)
+struct block_device *open_bdev_exclusive(const char *path, fmode_t mode, void *holder)
 {
        struct block_device *bdev;
-       mode_t mode = FMODE_READ;
        int error = 0;
 
        bdev = lookup_bdev(path);
        if (IS_ERR(bdev))
                return bdev;
 
-       if (!(flags & MS_RDONLY))
-               mode |= FMODE_WRITE;
-       error = blkdev_get(bdev, mode, 0);
+       error = blkdev_get(bdev, mode);
        if (error)
                return ERR_PTR(error);
        error = -EACCES;
-       if (!(flags & MS_RDONLY) && bdev_read_only(bdev))
+       if ((mode & FMODE_WRITE) && bdev_read_only(bdev))
                goto blkdev_put;
        error = bd_claim(bdev, holder);
        if (error)
@@ -1214,23 +1365,45 @@ struct block_device *open_bdev_excl(const char *path, int flags, void *holder)
        return bdev;
        
 blkdev_put:
-       blkdev_put(bdev);
+       blkdev_put(bdev, mode);
        return ERR_PTR(error);
 }
 
-EXPORT_SYMBOL(open_bdev_excl);
+EXPORT_SYMBOL(open_bdev_exclusive);
 
 /**
- * close_bdev_excl  -  release a blockdevice openen by open_bdev_excl()
+ * close_bdev_exclusive  -  close a blockdevice opened by open_bdev_exclusive()
  *
  * @bdev:      blockdevice to close
+ * @mode:      mode, must match that used to open.
  *
- * This is the counterpart to open_bdev_excl().
+ * This is the counterpart to open_bdev_exclusive().
  */
-void close_bdev_excl(struct block_device *bdev)
+void close_bdev_exclusive(struct block_device *bdev, fmode_t mode)
 {
        bd_release(bdev);
-       blkdev_put(bdev);
+       blkdev_put(bdev, mode);
 }
 
-EXPORT_SYMBOL(close_bdev_excl);
+EXPORT_SYMBOL(close_bdev_exclusive);
+
+int __invalidate_device(struct block_device *bdev)
+{
+       struct super_block *sb = get_super(bdev);
+       int res = 0;
+
+       if (sb) {
+               /*
+                * no need to lock the super, get_super holds the
+                * read mutex so the filesystem cannot go away
+                * under us (->put_super runs with the write lock
+                * hold).
+                */
+               shrink_dcache_sb(sb);
+               res = invalidate_inodes(sb);
+               drop_super(sb);
+       }
+       invalidate_bdev(bdev);
+       return res;
+}
+EXPORT_SYMBOL(__invalidate_device);