fat.h

/*
 * Copyright (c) 2008 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef FAT_FAT_H_
#define FAT_FAT_H_

#include "fat_fat.h"
#include <fibril_synch.h>
#include <libfs.h>
#include <atomic.h>
#include <sys/types.h>
#include <bool.h>
#include "../../vfs/vfs.h"

#ifndef dprintf
#define dprintf(...)    printf(__VA_ARGS__)
#endif

#define min(a, b)               ((a) < (b) ? (a) : (b))

/*
 * Convenience macros for accessing some frequently used boot sector members.
 */
#define BPS(bs)         uint16_t_le2host((bs)->bps)
#define SPC(bs)         (bs)->spc
#define RSCNT(bs)       uint16_t_le2host((bs)->rscnt)
#define FATCNT(bs)      (bs)->fatcnt
#define SF(bs)          uint16_t_le2host((bs)->sec_per_fat)
#define RDE(bs)         uint16_t_le2host((bs)->root_ent_max)
#define TS(bs)          (uint16_t_le2host((bs)->totsec16) != 0 ? \
                        uint16_t_le2host((bs)->totsec16) : \
                        uint32_t_le2host(bs->totsec32))

#define BS_BLOCK                0
#define BS_SIZE                 512

typedef struct fat_bs {
        uint8_t         ji[3];          
        uint8_t         oem_name[8];
        /* BIOS Parameter Block */
        uint16_t        bps;            
        uint8_t         spc;            
        uint16_t        rscnt;          
        uint8_t         fatcnt;         
        uint16_t        root_ent_max;   
        uint16_t        totsec16;       
        uint8_t         mdesc;          
        uint16_t        sec_per_fat;    
        uint16_t        sec_per_track;  
        uint16_t        headcnt;        
        uint32_t        hidden_sec;     
        uint32_t        totsec32;       
        union {
                struct {
                        /* FAT12/FAT16 only: Extended BIOS Parameter Block */
                        uint8_t         pdn;
                        uint8_t         reserved;
                        uint8_t         ebs;
                        uint32_t        id;
                        uint8_t         label[11];
                        uint8_t         type[8];
                        uint8_t         boot_code[448];
                        uint16_t        signature;
                } __attribute__ ((packed));
                struct {
                        /* FAT32 only */
                        uint32_t        sectors_per_fat;
                        uint16_t        flags;
                        uint16_t        version;
                        uint32_t        root_cluster;
                        uint16_t        fsinfo_sec;
                        uint16_t        bscopy_sec;
                        uint8_t         reserved1[12];
                        uint8_t         pdn;
                        uint8_t         reserved2;
                        uint8_t         ebs;
                        uint32_t        id;
                        uint8_t         label[11];
                        uint8_t         type[8];
                        uint8_t         boot_code[420];
                        uint16_t        signature;
                } fat32 __attribute__ ((packed));
        };
} __attribute__ ((packed)) fat_bs_t;

typedef enum {
        FAT_INVALID,
        FAT_DIRECTORY,
        FAT_FILE
} fat_node_type_t;

struct fat_node;

typedef struct {
        link_t          uph_link;
        link_t          uih_link;

        fibril_mutex_t  lock;
        devmap_handle_t devmap_handle;
        fs_index_t      index;
        fat_cluster_t   pfc;
        unsigned        pdi;
        struct fat_node *nodep;
} fat_idx_t;

typedef struct fat_node {
        fs_node_t               *bp;
        
        fibril_mutex_t          lock;
        fat_node_type_t         type;
        fat_idx_t               *idx;
        fat_cluster_t           firstc;
        link_t                  ffn_link;
        aoff64_t                size;
        unsigned                lnkcnt;
        unsigned                refcnt;
        bool                    dirty;

        /*
         * Cache of the node's last and "current" cluster to avoid some
         * unnecessary FAT walks.
         */
        /* Node's last cluster in FAT. */
        bool            lastc_cached_valid;
        fat_cluster_t   lastc_cached_value;
        /* Node's "current" cluster, i.e. where the last I/O took place. */
        bool            currc_cached_valid;
        aoff64_t        currc_cached_bn;
        fat_cluster_t   currc_cached_value;
} fat_node_t;

extern fs_reg_t fat_reg;

extern void fat_mounted(ipc_callid_t, ipc_call_t *);
extern void fat_mount(ipc_callid_t, ipc_call_t *);
extern void fat_unmounted(ipc_callid_t, ipc_call_t *);
extern void fat_unmount(ipc_callid_t, ipc_call_t *);
extern void fat_lookup(ipc_callid_t, ipc_call_t *);
extern void fat_read(ipc_callid_t, ipc_call_t *);
extern void fat_write(ipc_callid_t, ipc_call_t *);
extern void fat_truncate(ipc_callid_t, ipc_call_t *);
extern void fat_stat(ipc_callid_t, ipc_call_t *);
extern void fat_close(ipc_callid_t, ipc_call_t *);
extern void fat_destroy(ipc_callid_t, ipc_call_t *);
extern void fat_open_node(ipc_callid_t, ipc_call_t *);
extern void fat_stat(ipc_callid_t, ipc_call_t *);
extern void fat_sync(ipc_callid_t, ipc_call_t *);

extern int fat_idx_get_new(fat_idx_t **, devmap_handle_t);
extern fat_idx_t *fat_idx_get_by_pos(devmap_handle_t, fat_cluster_t, unsigned);
extern fat_idx_t *fat_idx_get_by_index(devmap_handle_t, fs_index_t);
extern void fat_idx_destroy(fat_idx_t *);
extern void fat_idx_hashin(fat_idx_t *);
extern void fat_idx_hashout(fat_idx_t *);

extern int fat_idx_init(void);
extern void fat_idx_fini(void);
extern int fat_idx_init_by_devmap_handle(devmap_handle_t);
extern void fat_idx_fini_by_devmap_handle(devmap_handle_t);

#endif

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