[PATCH] x86/powerpc make hardirq_ctx and softirq_ctx __read_mostly

[pandora-kernel.git] / fs / block_dev.c

diff --git a/fs/block_dev.c b/fs/block_dev.c
index af88c43..028d9fb 100644 (file)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -300,10 +300,10 @@ 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 = {
@@ -414,21 +414,31 @@ 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 +448,18 @@ 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)
@@ -1104,6 +1122,8 @@ const struct file_operations def_blk_fops = {
        .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,
 };
 
 int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg)