 8de5277879
			
		
	
	
	8de5277879
	
	
	
		
			
			New field of struct super_block - ->s_max_links. Maximal allowed value of ->i_nlink or 0; in the latter case all checks still need to be done in ->link/->mkdir/->rename instances. Note that this limit applies both to directoris and to non-directories. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
		
			
				
	
	
		
			247 lines
		
	
	
	
		
			7.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			247 lines
		
	
	
	
		
			7.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef _SYSV_H
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| #define _SYSV_H
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| 
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| #include <linux/buffer_head.h>
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| 
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| typedef __u16 __bitwise __fs16;
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| typedef __u32 __bitwise __fs32;
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| 
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| #include <linux/sysv_fs.h>
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| 
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| /*
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|  * SystemV/V7/Coherent super-block data in memory
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|  *
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|  * The SystemV/V7/Coherent superblock contains dynamic data (it gets modified
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|  * while the system is running). This is in contrast to the Minix and Berkeley
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|  * filesystems (where the superblock is never modified). This affects the
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|  * sync() operation: we must keep the superblock in a disk buffer and use this
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|  * one as our "working copy".
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|  */
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| 
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| struct sysv_sb_info {
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| 	struct super_block *s_sb;	/* VFS superblock */
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| 	int	       s_type;		/* file system type: FSTYPE_{XENIX|SYSV|COH} */
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| 	char	       s_bytesex;	/* bytesex (le/be/pdp) */
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| 	char	       s_truncate;	/* if 1: names > SYSV_NAMELEN chars are truncated */
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| 					/* if 0: they are disallowed (ENAMETOOLONG) */
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| 	unsigned int   s_inodes_per_block;	/* number of inodes per block */
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| 	unsigned int   s_inodes_per_block_1;	/* inodes_per_block - 1 */
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| 	unsigned int   s_inodes_per_block_bits;	/* log2(inodes_per_block) */
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| 	unsigned int   s_ind_per_block;		/* number of indirections per block */
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| 	unsigned int   s_ind_per_block_bits;	/* log2(ind_per_block) */
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| 	unsigned int   s_ind_per_block_2;	/* ind_per_block ^ 2 */
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| 	unsigned int   s_toobig_block;		/* 10 + ipb + ipb^2 + ipb^3 */
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| 	unsigned int   s_block_base;	/* physical block number of block 0 */
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| 	unsigned short s_fic_size;	/* free inode cache size, NICINOD */
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| 	unsigned short s_flc_size;	/* free block list chunk size, NICFREE */
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| 	/* The superblock is kept in one or two disk buffers: */
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| 	struct buffer_head *s_bh1;
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| 	struct buffer_head *s_bh2;
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| 	/* These are pointers into the disk buffer, to compensate for
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| 	   different superblock layout. */
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| 	char *         s_sbd1;		/* entire superblock data, for part 1 */
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| 	char *         s_sbd2;		/* entire superblock data, for part 2 */
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| 	__fs16         *s_sb_fic_count;	/* pointer to s_sbd->s_ninode */
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|         sysv_ino_t     *s_sb_fic_inodes; /* pointer to s_sbd->s_inode */
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| 	__fs16         *s_sb_total_free_inodes; /* pointer to s_sbd->s_tinode */
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| 	__fs16         *s_bcache_count;	/* pointer to s_sbd->s_nfree */
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| 	sysv_zone_t    *s_bcache;	/* pointer to s_sbd->s_free */
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| 	__fs32         *s_free_blocks;	/* pointer to s_sbd->s_tfree */
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| 	__fs32         *s_sb_time;	/* pointer to s_sbd->s_time */
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| 	__fs32         *s_sb_state;	/* pointer to s_sbd->s_state, only FSTYPE_SYSV */
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| 	/* We keep those superblock entities that don't change here;
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| 	   this saves us an indirection and perhaps a conversion. */
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| 	u32            s_firstinodezone; /* index of first inode zone */
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| 	u32            s_firstdatazone;	/* same as s_sbd->s_isize */
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| 	u32            s_ninodes;	/* total number of inodes */
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| 	u32            s_ndatazones;	/* total number of data zones */
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| 	u32            s_nzones;	/* same as s_sbd->s_fsize */
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| 	u16	       s_namelen;       /* max length of dir entry */
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| 	int	       s_forced_ro;
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| };
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| 
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| /*
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|  * SystemV/V7/Coherent FS inode data in memory
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|  */
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| struct sysv_inode_info {
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| 	__fs32		i_data[13];
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| 	u32		i_dir_start_lookup;
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| 	struct inode	vfs_inode;
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| };
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| 
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| 
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| static inline struct sysv_inode_info *SYSV_I(struct inode *inode)
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| {
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| 	return list_entry(inode, struct sysv_inode_info, vfs_inode);
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| }
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| 
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| static inline struct sysv_sb_info *SYSV_SB(struct super_block *sb)
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| {
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| 	return sb->s_fs_info;
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| }
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| 
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| 
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| /* identify the FS in memory */
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| enum {
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| 	FSTYPE_NONE = 0,
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| 	FSTYPE_XENIX,
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| 	FSTYPE_SYSV4,
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| 	FSTYPE_SYSV2,
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| 	FSTYPE_COH,
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| 	FSTYPE_V7,
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| 	FSTYPE_AFS,
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| 	FSTYPE_END,
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| };
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| 
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| #define SYSV_MAGIC_BASE		0x012FF7B3
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| 
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| #define XENIX_SUPER_MAGIC	(SYSV_MAGIC_BASE+FSTYPE_XENIX)
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| #define SYSV4_SUPER_MAGIC	(SYSV_MAGIC_BASE+FSTYPE_SYSV4)
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| #define SYSV2_SUPER_MAGIC	(SYSV_MAGIC_BASE+FSTYPE_SYSV2)
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| #define COH_SUPER_MAGIC		(SYSV_MAGIC_BASE+FSTYPE_COH)
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| 
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| 
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| /* Admissible values for i_nlink: 0.._LINK_MAX */
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| enum {
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| 	XENIX_LINK_MAX	=	126,	/* ?? */
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| 	SYSV_LINK_MAX	=	126,	/* 127? 251? */
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| 	V7_LINK_MAX     =	126,	/* ?? */
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| 	COH_LINK_MAX	=	10000,
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| };
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| 
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| 
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| static inline void dirty_sb(struct super_block *sb)
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| {
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| 	struct sysv_sb_info *sbi = SYSV_SB(sb);
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| 
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| 	mark_buffer_dirty(sbi->s_bh1);
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| 	if (sbi->s_bh1 != sbi->s_bh2)
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| 		mark_buffer_dirty(sbi->s_bh2);
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| 	sb->s_dirt = 1;
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| }
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| 
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| 
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| /* ialloc.c */
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| extern struct sysv_inode *sysv_raw_inode(struct super_block *, unsigned,
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| 			struct buffer_head **);
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| extern struct inode * sysv_new_inode(const struct inode *, umode_t);
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| extern void sysv_free_inode(struct inode *);
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| extern unsigned long sysv_count_free_inodes(struct super_block *);
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| 
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| /* balloc.c */
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| extern sysv_zone_t sysv_new_block(struct super_block *);
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| extern void sysv_free_block(struct super_block *, sysv_zone_t);
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| extern unsigned long sysv_count_free_blocks(struct super_block *);
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| 
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| /* itree.c */
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| extern void sysv_truncate(struct inode *);
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| extern int sysv_prepare_chunk(struct page *page, loff_t pos, unsigned len);
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| 
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| /* inode.c */
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| extern struct inode *sysv_iget(struct super_block *, unsigned int);
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| extern int sysv_write_inode(struct inode *, struct writeback_control *wbc);
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| extern int sysv_sync_inode(struct inode *);
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| extern void sysv_set_inode(struct inode *, dev_t);
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| extern int sysv_getattr(struct vfsmount *, struct dentry *, struct kstat *);
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| extern int sysv_init_icache(void);
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| extern void sysv_destroy_icache(void);
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| 
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| 
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| /* dir.c */
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| extern struct sysv_dir_entry *sysv_find_entry(struct dentry *, struct page **);
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| extern int sysv_add_link(struct dentry *, struct inode *);
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| extern int sysv_delete_entry(struct sysv_dir_entry *, struct page *);
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| extern int sysv_make_empty(struct inode *, struct inode *);
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| extern int sysv_empty_dir(struct inode *);
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| extern void sysv_set_link(struct sysv_dir_entry *, struct page *,
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| 			struct inode *);
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| extern struct sysv_dir_entry *sysv_dotdot(struct inode *, struct page **);
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| extern ino_t sysv_inode_by_name(struct dentry *);
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| 
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| 
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| extern const struct inode_operations sysv_file_inode_operations;
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| extern const struct inode_operations sysv_dir_inode_operations;
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| extern const struct inode_operations sysv_fast_symlink_inode_operations;
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| extern const struct file_operations sysv_file_operations;
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| extern const struct file_operations sysv_dir_operations;
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| extern const struct address_space_operations sysv_aops;
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| extern const struct super_operations sysv_sops;
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| extern const struct dentry_operations sysv_dentry_operations;
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| 
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| 
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| enum {
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| 	BYTESEX_LE,
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| 	BYTESEX_PDP,
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| 	BYTESEX_BE,
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| };
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| 
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| static inline u32 PDP_swab(u32 x)
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| {
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| #ifdef __LITTLE_ENDIAN
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| 	return ((x & 0xffff) << 16) | ((x & 0xffff0000) >> 16);
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| #else
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| #ifdef __BIG_ENDIAN
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| 	return ((x & 0xff00ff) << 8) | ((x & 0xff00ff00) >> 8);
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| #else
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| #error BYTESEX
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| #endif
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| #endif
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| }
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| 
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| static inline __u32 fs32_to_cpu(struct sysv_sb_info *sbi, __fs32 n)
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| {
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| 	if (sbi->s_bytesex == BYTESEX_PDP)
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| 		return PDP_swab((__force __u32)n);
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| 	else if (sbi->s_bytesex == BYTESEX_LE)
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| 		return le32_to_cpu((__force __le32)n);
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| 	else
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| 		return be32_to_cpu((__force __be32)n);
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| }
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| 
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| static inline __fs32 cpu_to_fs32(struct sysv_sb_info *sbi, __u32 n)
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| {
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| 	if (sbi->s_bytesex == BYTESEX_PDP)
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| 		return (__force __fs32)PDP_swab(n);
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| 	else if (sbi->s_bytesex == BYTESEX_LE)
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| 		return (__force __fs32)cpu_to_le32(n);
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| 	else
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| 		return (__force __fs32)cpu_to_be32(n);
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| }
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| 
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| static inline __fs32 fs32_add(struct sysv_sb_info *sbi, __fs32 *n, int d)
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| {
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| 	if (sbi->s_bytesex == BYTESEX_PDP)
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| 		*(__u32*)n = PDP_swab(PDP_swab(*(__u32*)n)+d);
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| 	else if (sbi->s_bytesex == BYTESEX_LE)
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| 		le32_add_cpu((__le32 *)n, d);
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| 	else
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| 		be32_add_cpu((__be32 *)n, d);
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| 	return *n;
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| }
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| 
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| static inline __u16 fs16_to_cpu(struct sysv_sb_info *sbi, __fs16 n)
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| {
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| 	if (sbi->s_bytesex != BYTESEX_BE)
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| 		return le16_to_cpu((__force __le16)n);
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| 	else
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| 		return be16_to_cpu((__force __be16)n);
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| }
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| 
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| static inline __fs16 cpu_to_fs16(struct sysv_sb_info *sbi, __u16 n)
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| {
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| 	if (sbi->s_bytesex != BYTESEX_BE)
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| 		return (__force __fs16)cpu_to_le16(n);
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| 	else
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| 		return (__force __fs16)cpu_to_be16(n);
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| }
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| 
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| static inline __fs16 fs16_add(struct sysv_sb_info *sbi, __fs16 *n, int d)
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| {
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| 	if (sbi->s_bytesex != BYTESEX_BE)
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| 		le16_add_cpu((__le16 *)n, d);
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| 	else
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| 		be16_add_cpu((__be16 *)n, d);
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| 	return *n;
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| }
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| 
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| #endif /* _SYSV_H */
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