Commit 8e656fd5 authored by Ryusuke Konishi's avatar Ryusuke Konishi
Browse files

nilfs2: make snapshots in checkpoint tree exportable 



The previous export operations cannot handle multiple versions of
a filesystem if they belong to the same sb instance.

This adds a new type of file handle and extends export operations so
that they can get the inode specified by a checkpoint number as well
as an inode number and a generation number.

Signed-off-by: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
parent 4d8d9293

fs/nilfs2/export.h

0 → 100644
+17 −0
Original line number Diff line number Diff line 
#ifndef NILFS_EXPORT_H

#define NILFS_EXPORT_H



#include <linux/exportfs.h>



extern const struct export_operations nilfs_export_ops;



struct nilfs_fid {

	u64 cno;

	u64 ino;

	u32 gen;



	u32 parent_gen;

	u64 parent_ino;

} __attribute__ ((packed));



#endif

fs/nilfs2/namei.c

+120 −17
Original line number Diff line number Diff line
@@ -40,7 +40,11 @@ 


#include <linux/pagemap.h>

#include "nilfs.h"

#include "export.h"



#define NILFS_FID_SIZE_NON_CONNECTABLE \

	(offsetof(struct nilfs_fid, parent_gen) / 4)

#define NILFS_FID_SIZE_CONNECTABLE	(sizeof(struct nilfs_fid) / 4)



static inline int nilfs_add_nondir(struct dentry *dentry, struct inode *inode)

{
@@ -77,23 +81,6 @@ nilfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) 
	return d_splice_alias(inode, dentry);

}



struct dentry *nilfs_get_parent(struct dentry *child)

{

	unsigned long ino;

	struct inode *inode;

	struct qstr dotdot = {.name = "..", .len = 2};



	ino = nilfs_inode_by_name(child->d_inode, &dotdot);

	if (!ino)

		return ERR_PTR(-ENOENT);



	inode = nilfs_iget(child->d_inode->i_sb,

			   NILFS_I(child->d_inode)->i_root, ino);

	if (IS_ERR(inode))

		return ERR_CAST(inode);

	return d_obtain_alias(inode);

}



/*

 * By the time this is called, we already have created

 * the directory cache entry for the new file, but it
@@ -469,6 +456,115 @@ out: 
	return err;

}



/*

 * Export operations

 */

static struct dentry *nilfs_get_parent(struct dentry *child)

{

	unsigned long ino;

	struct inode *inode;

	struct qstr dotdot = {.name = "..", .len = 2};

	struct nilfs_root *root;



	ino = nilfs_inode_by_name(child->d_inode, &dotdot);

	if (!ino)

		return ERR_PTR(-ENOENT);



	root = NILFS_I(child->d_inode)->i_root;



	inode = nilfs_iget(child->d_inode->i_sb, root, ino);

	if (IS_ERR(inode))

		return ERR_CAST(inode);



	return d_obtain_alias(inode);

}



static struct dentry *nilfs_get_dentry(struct super_block *sb, u64 cno,

				       u64 ino, u32 gen)

{

	struct nilfs_root *root;

	struct inode *inode;



	if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO)

		return ERR_PTR(-ESTALE);



	root = nilfs_lookup_root(NILFS_SB(sb)->s_nilfs, cno);

	if (!root)

		return ERR_PTR(-ESTALE);



	inode = nilfs_iget(sb, root, ino);

	nilfs_put_root(root);



	if (IS_ERR(inode))

		return ERR_CAST(inode);

	if (gen && inode->i_generation != gen) {

		iput(inode);

		return ERR_PTR(-ESTALE);

	}

	return d_obtain_alias(inode);

}



static struct dentry *nilfs_fh_to_dentry(struct super_block *sb, struct fid *fh,

					 int fh_len, int fh_type)

{

	struct nilfs_fid *fid = (struct nilfs_fid *)fh;



	if ((fh_len != NILFS_FID_SIZE_NON_CONNECTABLE &&

	     fh_len != NILFS_FID_SIZE_CONNECTABLE) ||

	    (fh_type != FILEID_NILFS_WITH_PARENT &&

	     fh_type != FILEID_NILFS_WITHOUT_PARENT))

		return NULL;



	return nilfs_get_dentry(sb, fid->cno, fid->ino, fid->gen);

}



static struct dentry *nilfs_fh_to_parent(struct super_block *sb, struct fid *fh,

					 int fh_len, int fh_type)

{

	struct nilfs_fid *fid = (struct nilfs_fid *)fh;



	if (fh_len != NILFS_FID_SIZE_CONNECTABLE ||

	    fh_type != FILEID_NILFS_WITH_PARENT)

		return NULL;



	return nilfs_get_dentry(sb, fid->cno, fid->parent_ino, fid->parent_gen);

}



static int nilfs_encode_fh(struct dentry *dentry, __u32 *fh, int *lenp,

			   int connectable)

{

	struct nilfs_fid *fid = (struct nilfs_fid *)fh;

	struct inode *inode = dentry->d_inode;

	struct nilfs_root *root = NILFS_I(inode)->i_root;

	int type;



	if (*lenp < NILFS_FID_SIZE_NON_CONNECTABLE ||

	    (connectable && *lenp < NILFS_FID_SIZE_CONNECTABLE))

		return 255;



	fid->cno = root->cno;

	fid->ino = inode->i_ino;

	fid->gen = inode->i_generation;



	if (connectable && !S_ISDIR(inode->i_mode)) {

		struct inode *parent;



		spin_lock(&dentry->d_lock);

		parent = dentry->d_parent->d_inode;

		fid->parent_ino = parent->i_ino;

		fid->parent_gen = parent->i_generation;

		spin_unlock(&dentry->d_lock);



		type = FILEID_NILFS_WITH_PARENT;

		*lenp = NILFS_FID_SIZE_CONNECTABLE;

	} else {

		type = FILEID_NILFS_WITHOUT_PARENT;

		*lenp = NILFS_FID_SIZE_NON_CONNECTABLE;

	}



	return type;

}



const struct inode_operations nilfs_dir_inode_operations = {

	.create		= nilfs_create,

	.lookup		= nilfs_lookup,
@@ -493,3 +589,10 @@ const struct inode_operations nilfs_symlink_inode_operations = { 
	.follow_link	= page_follow_link_light,

	.put_link	= page_put_link,

};



const struct export_operations nilfs_export_ops = {

	.encode_fh = nilfs_encode_fh,

	.fh_to_dentry = nilfs_fh_to_dentry,

	.fh_to_parent = nilfs_fh_to_parent,

	.get_parent = nilfs_get_parent,

};

fs/nilfs2/nilfs.h

+0 −3
Original line number Diff line number Diff line
@@ -264,9 +264,6 @@ extern int nilfs_set_file_dirty(struct nilfs_sb_info *, struct inode *, 
extern int nilfs_mark_inode_dirty(struct inode *);

extern void nilfs_dirty_inode(struct inode *);



/* namei.c */

extern struct dentry *nilfs_get_parent(struct dentry *);



/* super.c */

extern struct inode *nilfs_alloc_inode_common(struct the_nilfs *);

extern struct inode *nilfs_alloc_inode(struct super_block *);

fs/nilfs2/super.c

+1 −51
Original line number Diff line number Diff line
@@ -48,10 +48,10 @@ 
#include <linux/vfs.h>

#include <linux/writeback.h>

#include <linux/kobject.h>

#include <linux/exportfs.h>

#include <linux/seq_file.h>

#include <linux/mount.h>

#include "nilfs.h"

#include "export.h"

#include "mdt.h"

#include "alloc.h"

#include "btree.h"
@@ -556,56 +556,6 @@ static const struct super_operations nilfs_sops = { 
	.show_options = nilfs_show_options

};



static struct inode *

nilfs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation)

{

	struct inode *inode;

	struct nilfs_root *root;



	if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO &&

	    ino != NILFS_SKETCH_INO)

		return ERR_PTR(-ESTALE);



	root = nilfs_lookup_root(NILFS_SB(sb)->s_nilfs,

				 NILFS_CPTREE_CURRENT_CNO);

	if (!root)

		return ERR_PTR(-ESTALE);



	/* new file handle type is required to export snapshots */

	inode = nilfs_iget(sb, root, ino);

	nilfs_put_root(root);

	if (IS_ERR(inode))

		return ERR_CAST(inode);

	if (generation && inode->i_generation != generation) {

		iput(inode);

		return ERR_PTR(-ESTALE);

	}



	return inode;

}



static struct dentry *

nilfs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len,

		   int fh_type)

{

	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,

				    nilfs_nfs_get_inode);

}



static struct dentry *

nilfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len,

		   int fh_type)

{

	return generic_fh_to_parent(sb, fid, fh_len, fh_type,

				    nilfs_nfs_get_inode);

}



static const struct export_operations nilfs_export_ops = {

	.fh_to_dentry = nilfs_fh_to_dentry,

	.fh_to_parent = nilfs_fh_to_parent,

	.get_parent = nilfs_get_parent,

};



enum {

	Opt_err_cont, Opt_err_panic, Opt_err_ro,

	Opt_barrier, Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,

include/linux/exportfs.h

+13 −0
Original line number Diff line number Diff line
@@ -67,6 +67,19 @@ enum fid_type { 
	 * 32 bit parent block number, 32 bit parent generation number

	 */

	FILEID_UDF_WITH_PARENT = 0x52,



	/*

	 * 64 bit checkpoint number, 64 bit inode number,

	 * 32 bit generation number.

	 */

	FILEID_NILFS_WITHOUT_PARENT = 0x61,



	/*

	 * 64 bit checkpoint number, 64 bit inode number,

	 * 32 bit generation number, 32 bit parent generation.

	 * 64 bit parent inode number.

	 */

	FILEID_NILFS_WITH_PARENT = 0x62,

};



struct fid {

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