Re: [NFS] [PATCH] Make UDF exportable

[Jan Kara <jack@suse.cz>]

  Hi,

> Signed-off-by: Rasmus Rohde <rohde@duff.dk>
  Interesting character before Signed-off-by :).

> --- fs/udf/namei.c.orig	2007-10-10 16:22:30.000000000 +0200
> +++ fs/udf/namei.c	2008-02-05 18:28:13.000000000 +0100
> @@ -31,6 +31,7 @@
>  #include <linux/smp_lock.h>
>  #include <linux/buffer_head.h>
>  #include <linux/sched.h>
> +#include <linux/exportfs.h>
>  
>  static inline int udf_match(int len1, const char *name1, int len2,
>  			    const char *name2)
> @@ -315,9 +316,8 @@ static struct dentry *udf_lookup(struct 
>  		}
>  	}
>  	unlock_kernel();
> -	d_add(dentry, inode);
>  
> -	return NULL;
> +	return d_splice_alias(inode, dentry);
>  }
>  
>  static struct fileIdentDesc *udf_add_entry(struct inode *dir,
> @@ -1231,6 +1231,135 @@ end_rename:
>  	return retval;
>  }
>  
> +static struct dentry *udf_get_parent(struct dentry *child)
> +{
> +	struct dentry *parent;
> +	struct inode *inode = NULL;
> +	struct dentry dotdot;
> +	struct fileIdentDesc cfi;
> +	struct udf_fileident_bh fibh;
> +
> +	dotdot.d_name.name = "..";
> +	dotdot.d_name.len = 2;
> +
> +	lock_kernel();
> +	if (!udf_find_entry(child->d_inode, &dotdot, &fibh, &cfi))
> +		goto out_unlock;
  Have you ever tried this? I think this could never work. UDF doesn't have
entry named .. in a directory. You have to search for an entry that has
in fileCharacteristics set bit FID_FILE_CHAR_PARENT. Maybe you could
hack-around udf_find_entry() to recognize .. dentry and do the search
accordingly.

> +	
> +	if (fibh.sbh != fibh.ebh)
> +		brelse(fibh.ebh);
> +	brelse(fibh.sbh);
> +		
> +	inode = udf_iget(child->d_inode->i_sb,
> +			 lelb_to_cpu(cfi.icb.extLocation));
> +	if (!inode)
> +		goto out_unlock;
> +	unlock_kernel();
> +
> +	parent = d_alloc_anon(inode);
> +	if (!parent) {
> +		iput(inode);
> +		parent = ERR_PTR(-ENOMEM);
> +	}
> +
> +	return parent;
> +out_unlock:
> +	unlock_kernel();
> +	return ERR_PTR(-EACCES);
> +}
> +
> +
> +static struct dentry *udf_nfs_get_inode(struct super_block *sb, u32 block,
> +					u16 partref, __u32 generation)
> +{
> +	struct inode *inode;
> +	struct dentry *result;
> +	kernel_lb_addr loc;
> +
> +	if (block == 0)
> +		return ERR_PTR(-ESTALE);
> +
> +	loc.logicalBlockNum = block;
> +	loc.partitionReferenceNum = partref;
> +	inode = udf_iget(sb, loc);
> +
> +	if (inode == NULL)
> +		return ERR_PTR(-ENOMEM);
> +
> +	if (generation && inode->i_generation != generation) {
> +		iput(inode);
> +		return ERR_PTR(-ESTALE);
> +	}
> +	result = d_alloc_anon(inode);
> +	if (!result) {
> +		iput(inode);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +	return result;
> +}
> +
> +static struct dentry *udf_fh_to_dentry(struct super_block *sb,
> +				       struct fid *fid, int fh_len, int fh_type)
> +{
> +	if ((fh_len != 3 && fh_len != 5) ||
> +	    (fh_type != FILEID_UDF_WITH_PARENT &&
> +	     fh_type != FILEID_UDF_WITHOUT_PARENT))
> +		return NULL;
> +
> +	return udf_nfs_get_inode(sb, fid->udf.block, fid->udf.partref,
> +			fid->udf.generation);
> +}
> +
> +static struct dentry *udf_fh_to_parent(struct super_block *sb,
> +				       struct fid *fid, int fh_len, int fh_type)
> +{
> +	if (fh_len != 5 || fh_type != FILEID_UDF_WITHOUT_PARENT)
> +		return NULL;
> +
> +	return udf_nfs_get_inode(sb, fid->udf.parent_block,
> +				 fid->udf.parent_partref,
> +				 fid->udf.parent_generation);
> +}
> +static int udf_encode_fh(struct dentry *de, __u32 *fh, int *lenp,
> +			 int connectable)
> +{
> +	int len = *lenp;
> +	struct inode *inode =  de->d_inode;
> +	kernel_lb_addr location = UDF_I_LOCATION(inode);
> +	struct fid *fid = (struct fid *)fh;
> +	int type = FILEID_UDF_WITHOUT_PARENT;
> +
> +	if (len < 3 || (connectable && len < 5))
> +		return 255;
> +
> +	*lenp = 3;
> +	fid->udf.block = location.logicalBlockNum;
> +	fid->udf.partref = location.partitionReferenceNum;
> +	fid->udf.generation = inode->i_generation;
> +
> +	if (connectable && !S_ISDIR(inode->i_mode)) {
> +		spin_lock(&de->d_lock);
> +		inode = de->d_parent->d_inode;
> +		location = UDF_I_LOCATION(inode);
> +		fid->udf.parent_block = location.logicalBlockNum;
> +		fid->udf.parent_partref = location.partitionReferenceNum;	
> +		fid->udf.parent_generation = inode->i_generation;
> +		spin_unlock(&de->d_lock);
> +		*lenp = 5;
> +		type = FILEID_UDF_WITH_PARENT;
> +	}
> +
> +	return type;
> +}
> +
> +struct export_operations udf_export_ops = {
> +	.encode_fh	= udf_encode_fh,
> +	.fh_to_dentry   = udf_fh_to_dentry,
> +	.fh_to_parent   = udf_fh_to_parent,
> +	.get_parent     = udf_get_parent,
> +};
> +
>  const struct inode_operations udf_dir_inode_operations = {
>  	.lookup				= udf_lookup,
>  	.create				= udf_create,
> 
> --- fs/udf/super.c.orig	2008-01-30 17:57:23.000000000 +0100
> +++ fs/udf/super.c	2008-01-30 21:38:10.000000000 +0100
> @@ -71,7 +71,7 @@
>  #define VDS_POS_LENGTH			7
>  
>  static char error_buf[1024];
> -
> +extern struct export_operations udf_export_ops;
>  /* These are the "meat" - everything else is stuffing */
>  static int udf_fill_super(struct super_block *, void *, int);
>  static void udf_put_super(struct super_block *);
> @@ -1490,6 +1490,7 @@ static int udf_fill_super(struct super_b
>  
>  	/* Fill in the rest of the superblock */
>  	sb->s_op = &udf_sb_ops;
> +	sb->s_export_op = &udf_export_ops;
>  	sb->dq_op = NULL;
>  	sb->s_dirt = 0;
>  	sb->s_magic = UDF_SUPER_MAGIC;
> 
> --- include/linux/exportfs.h.orig	2008-02-05 18:28:44.000000000 +0100
> +++ include/linux/exportfs.h	2008-02-05 18:28:51.000000000 +0100
> @@ -33,6 +33,19 @@ enum fid_type {
>  	 * 32 bit parent directory inode number.
>  	 */
>  	FILEID_INO32_GEN_PARENT = 2,
> +
> +	/*
> +	 * 32 bit block number, 16 bit partition reference,
> +	 * 16 bit unused, 32 bit generation number.
> +	 */
> +	FILEID_UDF_WITHOUT_PARENT = 0x51,
> +
> +	/*
> +	 * 32 bit block number, 16 bit partition reference,
> +	 * 16 bit unused, 32 bit generation number,
> +	 * 32 bit parent block number, 32 bit parent generation number
> +	 */
> +	FILEID_UDF_WITH_PARENT = 0x52,
>  };
>  
>  struct fid {
> @@ -43,6 +56,14 @@ struct fid {
>  			u32 parent_ino;
>  			u32 parent_gen;
>  		} i32;
> +		struct {
> +			u32 block;
> +			u16 partref;
> +			u16 parent_partref;
> +			u32 generation;
> +			u32 parent_block;
> +			u32 parent_generation;
> +		} udf;
>  		__u32 raw[6];
>  	};
>  };
  Otherwise the patch looks fine. But please rediff the patch against
Andrew's development tree (or -mm) because there are some cleanups there...
Thanks.

									Honza
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR
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