210 lines
9.2 KiB
C
210 lines
9.2 KiB
C
/*
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* Data structures for 2.xBSD filesystem.
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*
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* Copyright (C) 2006-2011 Serge Vakulenko, <serge@vak.ru>
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*
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* Permission to use, copy, modify, and distribute this software
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* and its documentation for any purpose and without fee is hereby
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* granted, provided that the above copyright notice appear in all
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* copies and that both that the copyright notice and this
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* permission notice and warranty disclaimer appear in supporting
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* documentation, and that the name of the author not be used in
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* advertising or publicity pertaining to distribution of the
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* software without specific, written prior permission.
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*
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* The author disclaim all warranties with regard to this
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* software, including all implied warranties of merchantability
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* and fitness. In no event shall the author be liable for any
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* special, indirect or consequential damages or any damages
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* whatsoever resulting from loss of use, data or profits, whether
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* in an action of contract, negligence or other tortious action,
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* arising out of or in connection with the use or performance of
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* this software.
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*/
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#define BSDFS_BSIZE 1024 /* block size */
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#define BSDFS_ROOT_INODE 2 /* root directory in inode 2 */
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#define BSDFS_LOSTFOUND_INODE 3 /* lost+found directory in inode 3 */
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#define BSDFS_SWAP_INODE 4 /* swap file in inode 4 */
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#define BSDFS_INODES_PER_BLOCK 16 /* inodes per block */
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#define NICINOD 32 /* number of superblock inodes */
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#define NICFREE 200 /* number of superblock free blocks */
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/*
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* 28 of the di_addr address bytes are used; 7 addresses of 4
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* bytes each: 4 direct (4Kb directly accessible) and 3 indirect.
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*/
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#define NDADDR 4 /* direct addresses in inode */
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#define NIADDR 3 /* indirect addresses in inode */
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#define NADDR (NDADDR + NIADDR) /* total addresses in inode */
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/*
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* NINDIR is the number of indirects in a file system block.
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*/
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#define NINDIR (DEV_BSIZE / sizeof(daddr_t))
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#define NSHIFT 8 /* log2(NINDIR) */
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#define NMASK 0377L /* NINDIR - 1 */
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/*
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* The path name on which the file system is mounted is maintained
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* in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
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* the super block for this name.
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*/
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#define MAXMNTLEN 28
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#define FSMAGIC1 ('F' | 'S'<<8 | '<'<<16 | '<'<<24)
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#define FSMAGIC2 ('>' | '>'<<8 | 'F'<<16 | 'S'<<24)
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typedef struct {
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const char *filename;
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int fd;
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unsigned long seek;
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int writable;
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int dirty; /* sync needed */
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int modified; /* write_block was called */
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unsigned isize; /* size in blocks of superblock + I list */
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unsigned fsize; /* size in blocks of entire volume */
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unsigned swapsz; /* size in blocks of swap area */
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unsigned nfree; /* number of in core free blocks (0-100) */
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unsigned free [NICFREE]; /* in core free blocks */
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unsigned ninode; /* number of in core I nodes (0-100) */
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unsigned inode [NICINOD]; /* in core free I nodes */
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unsigned flock; /* lock during free list manipulation */
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unsigned ilock; /* lock during I list manipulation */
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unsigned fmod; /* super block modified flag */
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unsigned ronly; /* mounted read-only flag */
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long utime; /* current date of last update */
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unsigned tfree; /* total free blocks */
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unsigned tinode; /* total free inodes */
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char fsmnt [MAXMNTLEN]; /* ordinary file mounted on */
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unsigned lasti; /* start place for circular search */
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unsigned nbehind; /* est # free inodes before s_lasti */
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unsigned flags; /* mount time flags */
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} fs_t;
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typedef struct {
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fs_t *fs;
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unsigned number;
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int dirty; /* save needed */
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unsigned short mode; /* file type and access mode */
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#define INODE_MODE_FMT 0170000 /* type of file */
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#define INODE_MODE_FCHR 020000 /* character special */
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#define INODE_MODE_FDIR 040000 /* directory */
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#define INODE_MODE_FBLK 060000 /* block special */
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#define INODE_MODE_FREG 0100000 /* regular */
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#define INODE_MODE_FLNK 0120000 /* symbolic link */
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#define INODE_MODE_FSOCK 0140000 /* socket */
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#define INODE_MODE_SUID 04000 /* set user id on execution */
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#define INODE_MODE_SGID 02000 /* set group id on execution */
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#define INODE_MODE_SVTX 01000 /* save swapped text even after use */
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#define INODE_MODE_READ 0400 /* read, write, execute permissions */
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#define INODE_MODE_WRITE 0200
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#define INODE_MODE_EXEC 0100
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unsigned short nlink; /* directory entries */
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unsigned uid; /* owner */
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unsigned gid; /* group */
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unsigned long size; /* size */
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unsigned addr [7]; /* device addresses constituting file */
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unsigned flags; /* user defined flags */
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/*
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* Super-user and owner changeable flags.
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*/
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#define USER_SETTABLE 0x00ff /* mask of owner changeable flags */
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#define USER_NODUMP 0x0001 /* do not dump file */
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#define USER_IMMUTABLE 0x0002 /* file may not be changed */
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#define USER_APPEND 0x0004 /* writes to file may only append */
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/*
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* Super-user changeable flags.
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*/
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#define SYS_SETTABLE 0xff00 /* mask of superuser changeable flags */
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#define SYS_ARCHIVED 0x0100 /* file is archived */
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#define SYS_IMMUTABLE 0x0200 /* file may not be changed */
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#define SYS_APPEND 0x0400 /* writes to file may only append */
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long atime; /* time last accessed */
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long mtime; /* time last modified */
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long ctime; /* time created */
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} fs_inode_t;
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typedef struct {
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unsigned ino;
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unsigned reclen;
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unsigned namlen;
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char name [63+1];
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} fs_dirent_t;
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typedef void (*fs_directory_scanner_t) (fs_inode_t *dir,
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fs_inode_t *file, char *dirname, char *filename, void *arg);
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typedef struct {
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fs_inode_t inode;
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int writable; /* write allowed */
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unsigned long offset; /* current i/o offset */
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} fs_file_t;
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typedef enum {
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INODE_OP_LOOKUP, /* lookup inode by name */
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INODE_OP_CREATE, /* create new file */
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INODE_OP_DELETE, /* delete file */
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INODE_OP_LINK, /* make a link to a file */
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} fs_op_t;
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int fs_seek (fs_t *fs, unsigned long offset);
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int fs_read8 (fs_t *fs, unsigned char *val);
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int fs_read16 (fs_t *fs, unsigned short *val);
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int fs_read32 (fs_t *fs, unsigned *val);
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int fs_write8 (fs_t *fs, unsigned char val);
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int fs_write16 (fs_t *fs, unsigned short val);
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int fs_write32 (fs_t *fs, unsigned val);
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int fs_read (fs_t *fs, unsigned char *data, int bytes);
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int fs_write (fs_t *fs, unsigned char *data, int bytes);
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int fs_open (fs_t *fs, const char *filename, int writable);
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void fs_close (fs_t *fs);
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int fs_sync (fs_t *fs, int force);
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int fs_create (fs_t *fs, const char *filename, unsigned kbytes,
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unsigned swap_kbytes);
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int fs_check (fs_t *fs);
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void fs_print (fs_t *fs, FILE *out);
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int fs_mount(fs_t *fs, char *dirname);
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int fs_inode_get (fs_t *fs, fs_inode_t *inode, unsigned inum);
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int fs_inode_save (fs_inode_t *inode, int force);
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void fs_inode_clear (fs_inode_t *inode);
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void fs_inode_truncate (fs_inode_t *inode, unsigned long size);
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void fs_inode_print (fs_inode_t *inode, FILE *out);
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int fs_inode_read (fs_inode_t *inode, unsigned long offset,
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unsigned char *data, unsigned long bytes);
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int fs_inode_write (fs_inode_t *inode, unsigned long offset,
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unsigned char *data, unsigned long bytes);
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int fs_inode_alloc (fs_t *fs, fs_inode_t *inode);
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int fs_inode_by_name (fs_t *fs, fs_inode_t *inode, const char *name,
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fs_op_t op, int mode);
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int inode_build_list (fs_t *fs);
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int fs_write_block (fs_t *fs, unsigned bnum, unsigned char *data);
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int fs_read_block (fs_t *fs, unsigned bnum, unsigned char *data);
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int fs_block_free (fs_t *fs, unsigned int bno);
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int fs_block_alloc (fs_t *fs, unsigned int *bno);
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int fs_indirect_block_free (fs_t *fs, unsigned int bno, int nblk);
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int fs_double_indirect_block_free (fs_t *fs, unsigned int bno, int nblk);
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int fs_triple_indirect_block_free (fs_t *fs, unsigned int bno, int nblk);
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void fs_directory_scan (fs_inode_t *inode, char *dirname,
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fs_directory_scanner_t scanner, void *arg);
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void fs_dirent_pack (unsigned char *data, fs_dirent_t *dirent);
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void fs_dirent_unpack (fs_dirent_t *dirent, unsigned char *data);
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int fs_file_create (fs_t *fs, fs_file_t *file, const char *name, int mode);
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int fs_file_open (fs_t *fs, fs_file_t *file, const char *name, int wflag);
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int fs_file_read (fs_file_t *file, unsigned char *data,
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unsigned long bytes);
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int fs_file_write (fs_file_t *file, unsigned char *data,
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unsigned long bytes);
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int fs_file_close (fs_file_t *file);
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