block: introduce bdev_file_inode()

Similar to the file_inode() helper, provide a helper to lookup the inode for a
raw block device itself.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 44d4a1e9244e74e923d7b26018d4b420aa2e1323..52248bce42d28de4861013856c155f6b35d221d8 100644 (file)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -156,11 +156,16 @@ blkdev_get_block(struct inode *inode, sector_t iblock,
        return 0;
 }
 
+static struct inode *bdev_file_inode(struct file *file)
+{
+       return file->f_mapping->host;
+}
+
 static ssize_t
 blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t offset)
 {
        struct file *file = iocb->ki_filp;
-       struct inode *inode = file->f_mapping->host;
+       struct inode *inode = bdev_file_inode(file);
 
        if (IS_DAX(inode))
                return dax_do_io(iocb, inode, iter, offset, blkdev_get_block,
@@ -338,7 +343,7 @@ static int blkdev_write_end(struct file *file, struct address_space *mapping,
  */
 static loff_t block_llseek(struct file *file, loff_t offset, int whence)
 {
-       struct inode *bd_inode = file->f_mapping->host;
+       struct inode *bd_inode = bdev_file_inode(file);
        loff_t retval;
 
        mutex_lock(&bd_inode->i_mutex);
@@ -349,7 +354,7 @@ static loff_t block_llseek(struct file *file, loff_t offset, int whence)
        
 int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
 {
-       struct inode *bd_inode = filp->f_mapping->host;
+       struct inode *bd_inode = bdev_file_inode(filp);
        struct block_device *bdev = I_BDEV(bd_inode);
        int error;
        
@@ -1605,14 +1610,14 @@ EXPORT_SYMBOL(blkdev_put);
 
 static int blkdev_close(struct inode * inode, struct file * filp)
 {
-       struct block_device *bdev = I_BDEV(filp->f_mapping->host);
+       struct block_device *bdev = I_BDEV(bdev_file_inode(filp));
        blkdev_put(bdev, filp->f_mode);
        return 0;
 }
 
 static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 {
-       struct block_device *bdev = I_BDEV(file->f_mapping->host);
+       struct block_device *bdev = I_BDEV(bdev_file_inode(file));
        fmode_t mode = file->f_mode;
 
        /*
@@ -1637,7 +1642,7 @@ static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
        struct file *file = iocb->ki_filp;
-       struct inode *bd_inode = file->f_mapping->host;
+       struct inode *bd_inode = bdev_file_inode(file);
        loff_t size = i_size_read(bd_inode);
        struct blk_plug plug;
        ssize_t ret;
@@ -1669,7 +1674,7 @@ EXPORT_SYMBOL_GPL(blkdev_write_iter);
 ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
        struct file *file = iocb->ki_filp;
-       struct inode *bd_inode = file->f_mapping->host;
+       struct inode *bd_inode = bdev_file_inode(file);
        loff_t size = i_size_read(bd_inode);
        loff_t pos = iocb->ki_pos;