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Commit ea3983ac authored by Namjae Jeon's avatar Namjae Jeon Committed by Linus Torvalds
Browse files

fat: restructure export_operations 



Define two nfs export_operation structures,one for 'stale_rw' mounts and
the other for 'nostale_ro'.  The latter uses i_pos as a basis for encoding
and decoding file handles.

Also, assign i_pos to kstat->ino.  The logic for rebuilding the inode is
added in the subsequent patches.

Signed-off-by: default avatarNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: default avatarRavishankar N <ravi.n1@samsung.com>
Signed-off-by: default avatarAmit Sahrawat <a.sahrawat@samsung.com>
Acked-by: default avatarOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e22a4442

fs/fat/fat.h

+2 −6
Original line number Diff line number Diff line
@@ -406,12 +406,8 @@ int fat_cache_init(void); 
void fat_cache_destroy(void);



/* fat/nfs.c */

struct fid;

extern struct dentry *fat_fh_to_dentry(struct super_block *sb, struct fid *fid,

				       int fh_len, int fh_type);

extern struct dentry *fat_fh_to_parent(struct super_block *sb, struct fid *fid,

				       int fh_len, int fh_type);

extern struct dentry *fat_get_parent(struct dentry *child_dir);

extern const struct export_operations fat_export_ops;

extern const struct export_operations fat_export_ops_nostale;



/* helper for printk */

typedef unsigned long long	llu;

fs/fat/file.c

+5 −0
Original line number Diff line number Diff line
@@ -306,6 +306,11 @@ int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 
	struct inode *inode = dentry->d_inode;

	generic_fillattr(inode, stat);

	stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size;



	if (MSDOS_SB(inode->i_sb)->options.nfs == FAT_NFS_NOSTALE_RO) {

		/* Use i_pos for ino. This is used as fileid of nfs. */

		stat->ino = fat_i_pos_read(MSDOS_SB(inode->i_sb), inode);

	}

	return 0;

}

EXPORT_SYMBOL_GPL(fat_getattr);

fs/fat/inode.c

+4 −9
Original line number Diff line number Diff line
@@ -18,7 +18,6 @@ 
#include <linux/pagemap.h>

#include <linux/mpage.h>

#include <linux/buffer_head.h>

#include <linux/exportfs.h>

#include <linux/mount.h>

#include <linux/vfs.h>

#include <linux/parser.h>
@@ -748,12 +747,6 @@ static const struct super_operations fat_sops = { 
	.show_options	= fat_show_options,

};



static const struct export_operations fat_export_ops = {

	.fh_to_dentry	= fat_fh_to_dentry,

	.fh_to_parent	= fat_fh_to_parent,

	.get_parent	= fat_get_parent,

};



static int fat_show_options(struct seq_file *m, struct dentry *root)

{

	struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
@@ -1177,8 +1170,10 @@ out: 
		opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);

	if (opts->unicode_xlate)

		opts->utf8 = 0;

	if (opts->nfs == FAT_NFS_NOSTALE_RO)

	if (opts->nfs == FAT_NFS_NOSTALE_RO) {

		sb->s_flags |= MS_RDONLY;

		sb->s_export_op = &fat_export_ops_nostale;

	}



	return 0;

}
@@ -1189,7 +1184,7 @@ static int fat_read_root(struct inode *inode) 
	struct msdos_sb_info *sbi = MSDOS_SB(sb);

	int error;



	MSDOS_I(inode)->i_pos = 0;

	MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;

	inode->i_uid = sbi->options.fs_uid;

	inode->i_gid = sbi->options.fs_gid;

	inode->i_version++;

fs/fat/nfs.c

+125 −5
Original line number Diff line number Diff line
@@ -14,6 +14,18 @@ 
#include <linux/exportfs.h>

#include "fat.h"



struct fat_fid {

	u32 i_gen;

	u32 i_pos_low;

	u16 i_pos_hi;

	u16 parent_i_pos_hi;

	u32 parent_i_pos_low;

	u32 parent_i_gen;

};



#define FAT_FID_SIZE_WITHOUT_PARENT 3

#define FAT_FID_SIZE_WITH_PARENT (sizeof(struct fat_fid)/sizeof(u32))



/**

 * Look up a directory inode given its starting cluster.

 */
@@ -38,8 +50,8 @@ static struct inode *fat_dget(struct super_block *sb, int i_logstart) 
	return inode;

}



static struct inode *fat_nfs_get_inode(struct super_block *sb,

				       u64 ino, u32 generation)

static struct inode *__fat_nfs_get_inode(struct super_block *sb,

				       u64 ino, u32 generation, loff_t i_pos)

{

	struct inode *inode;
@@ -55,35 +67,130 @@ static struct inode *fat_nfs_get_inode(struct super_block *sb, 
	return inode;

}



static struct inode *fat_nfs_get_inode(struct super_block *sb,

				       u64 ino, u32 generation)

{



	return __fat_nfs_get_inode(sb, ino, generation, 0);

}



static int

fat_encode_fh_nostale(struct inode *inode, __u32 *fh, int *lenp,

		      struct inode *parent)

{

	int len = *lenp;

	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);

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

	loff_t i_pos;

	int type = FILEID_FAT_WITHOUT_PARENT;



	if (parent) {

		if (len < FAT_FID_SIZE_WITH_PARENT) {

			*lenp = FAT_FID_SIZE_WITH_PARENT;

			return FILEID_INVALID;

		}

	} else {

		if (len < FAT_FID_SIZE_WITHOUT_PARENT) {

			*lenp = FAT_FID_SIZE_WITHOUT_PARENT;

			return FILEID_INVALID;

		}

	}



	i_pos = fat_i_pos_read(sbi, inode);

	*lenp = FAT_FID_SIZE_WITHOUT_PARENT;

	fid->i_gen = inode->i_generation;

	fid->i_pos_low = i_pos & 0xFFFFFFFF;

	fid->i_pos_hi = (i_pos >> 32) & 0xFFFF;

	if (parent) {

		i_pos = fat_i_pos_read(sbi, parent);

		fid->parent_i_pos_hi = (i_pos >> 32) & 0xFFFF;

		fid->parent_i_pos_low = i_pos & 0xFFFFFFFF;

		fid->parent_i_gen = parent->i_generation;

		type = FILEID_FAT_WITH_PARENT;

		*lenp = FAT_FID_SIZE_WITH_PARENT;

	}



	return type;

}



/**

 * Map a NFS file handle to a corresponding dentry.

 * The dentry may or may not be connected to the filesystem root.

 */

struct dentry *fat_fh_to_dentry(struct super_block *sb, struct fid *fid,

static struct dentry *fat_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,

				    fat_nfs_get_inode);

}



static struct dentry *fat_fh_to_dentry_nostale(struct super_block *sb,

					       struct fid *fh, int fh_len,

					       int fh_type)

{

	struct inode *inode = NULL;

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

	loff_t i_pos;



	switch (fh_type) {

	case FILEID_FAT_WITHOUT_PARENT:

		if (fh_len < FAT_FID_SIZE_WITHOUT_PARENT)

			return NULL;

		break;

	case FILEID_FAT_WITH_PARENT:

		if (fh_len < FAT_FID_SIZE_WITH_PARENT)

			return NULL;

		break;

	default:

		return NULL;

	}

	i_pos = fid->i_pos_hi;

	i_pos = (i_pos << 32) | (fid->i_pos_low);

	inode = __fat_nfs_get_inode(sb, 0, fid->i_gen, i_pos);



	return d_obtain_alias(inode);

}



/*

 * Find the parent for a file specified by NFS handle.

 * This requires that the handle contain the i_ino of the parent.

 */

struct dentry *fat_fh_to_parent(struct super_block *sb, struct fid *fid,

static struct dentry *fat_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,

				    fat_nfs_get_inode);

}



static struct dentry *fat_fh_to_parent_nostale(struct super_block *sb,

					       struct fid *fh, int fh_len,

					       int fh_type)

{

	struct inode *inode = NULL;

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

	loff_t i_pos;



	if (fh_len < FAT_FID_SIZE_WITH_PARENT)

		return NULL;



	switch (fh_type) {

	case FILEID_FAT_WITH_PARENT:

		i_pos = fid->parent_i_pos_hi;

		i_pos = (i_pos << 32) | (fid->parent_i_pos_low);

		inode = __fat_nfs_get_inode(sb, 0, fid->parent_i_gen, i_pos);

		break;

	}



	return d_obtain_alias(inode);

}



/*

 * Find the parent for a directory that is not currently connected to

 * the filesystem root.

 *

 * On entry, the caller holds child_dir->d_inode->i_mutex.

 */

struct dentry *fat_get_parent(struct dentry *child_dir)

static struct dentry *fat_get_parent(struct dentry *child_dir)

{

	struct super_block *sb = child_dir->d_sb;

	struct buffer_head *bh = NULL;
@@ -98,3 +205,16 @@ struct dentry *fat_get_parent(struct dentry *child_dir) 


	return d_obtain_alias(parent_inode);

}



const struct export_operations fat_export_ops = {

	.fh_to_dentry   = fat_fh_to_dentry,

	.fh_to_parent   = fat_fh_to_parent,

	.get_parent     = fat_get_parent,

};



const struct export_operations fat_export_ops_nostale = {

	.encode_fh      = fat_encode_fh_nostale,

	.fh_to_dentry   = fat_fh_to_dentry_nostale,

	.fh_to_parent   = fat_fh_to_parent_nostale,

	.get_parent     = fat_get_parent,

};

include/linux/exportfs.h

+11 −0
Original line number Diff line number Diff line
@@ -84,6 +84,17 @@ enum fid_type { 
	 */

	FILEID_NILFS_WITH_PARENT = 0x62,



	/*

	 * 32 bit generation number, 40 bit i_pos.

	 */

	FILEID_FAT_WITHOUT_PARENT = 0x71,



	/*

	 * 32 bit generation number, 40 bit i_pos,

	 * 32 bit parent generation number, 40 bit parent i_pos

	 */

	FILEID_FAT_WITH_PARENT = 0x72,



	/*

	 * Filesystems must not use 0xff file ID.

	 */