1,5 → 1,5 |
/* |
* Copyright (c) 2007 Jakub Jermar |
* Copyright (c) 2008 Jakub Jermar |
* All rights reserved. |
* |
* Redistribution and use in source and binary forms, with or without |
38,8 → 38,11 |
#include <atomic.h> |
#include <sys/types.h> |
#include <bool.h> |
#include "../../vfs/vfs.h" |
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#ifndef dprintf |
#define dprintf(...) printf(__VA_ARGS__) |
#endif |
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typedef struct { |
uint8_t ji[3]; /**< Jump instruction. */ |
47,17 → 50,17 |
/* BIOS Parameter Block */ |
uint16_t bps; /**< Bytes per sector. */ |
uint8_t spc; /**< Sectors per cluster. */ |
uint16_t rsc; /**< Reserved sector count. */ |
uint16_t rscnt; /**< Reserved sector count. */ |
uint8_t fatcnt; /**< Number of FATs. */ |
uint16_t root_ent_max; /**< Maximum number of root directory |
entries. */ |
uint16_t totsec; /**< Total sectors. */ |
uint16_t totsec16; /**< Total sectors. 16-bit version. */ |
uint8_t mdesc; /**< Media descriptor. */ |
uint16_t sec_per_fat; /**< Sectors per FAT12/FAT16. */ |
uint16_t sec_per_track; /**< Sectors per track. */ |
uint16_t headcnt; /**< Number of heads. */ |
uint32_t hidden_sec; /**< Hidden sectors. */ |
uint32_t total_sec; /**< Total sectors. */ |
uint32_t totsec32; /**< Total sectors. 32-bit version. */ |
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union { |
struct { |
101,7 → 104,7 |
/** Serial number. */ |
uint32_t id; |
/** Volume label. */ |
uint8_t label; |
uint8_t label[11]; |
/** FAT type. */ |
uint8_t type[8]; |
/** Boot code. */ |
112,6 → 115,10 |
}; |
} __attribute__ ((packed)) fat_bs_t; |
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#define FAT_ATTR_RDONLY (1 << 0) |
#define FAT_ATTR_VOLLABEL (1 << 3) |
#define FAT_ATTR_SUBDIR (1 << 4) |
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typedef struct { |
uint8_t name[8]; |
uint8_t ext[3]; |
134,10 → 141,97 |
uint32_t size; |
} __attribute__ ((packed)) fat_dentry_t; |
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typedef uint16_t fat_cluster_t; |
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typedef enum { |
FAT_INVALID, |
FAT_DIRECTORY, |
FAT_FILE |
} fat_node_type_t; |
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struct fat_node; |
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/** FAT index structure. |
* |
* This structure exists to help us to overcome certain limitations of the FAT |
* file system design. The problem with FAT is that it is hard to find |
* an entity which could represent a VFS index. There are two candidates: |
* |
* a) number of the node's first cluster |
* b) the pair of the parent directory's first cluster and the dentry index |
* within the parent directory |
* |
* We need VFS indices to be: |
* A) unique |
* B) stable in time, at least until the next mount |
* |
* Unfortunately a) does not meet the A) criterion because zero-length files |
* will have the first cluster field cleared. And b) does not meet the B) |
* criterion because unlink() and rename() will both free up the original |
* dentry, which contains all the essential info about the file. |
* |
* Therefore, a completely opaque indices are used and the FAT server maintains |
* a mapping between them and otherwise nice b) variant. On rename(), the VFS |
* index stays unaltered, while the internal FAT "physical tree address" |
* changes. The unlink case is also handled this way thanks to an in-core node |
* pointer embedded in the index structure. |
*/ |
typedef struct { |
/** Used indices (position) hash table link. */ |
link_t uph_link; |
/** Used indices (index) hash table link. */ |
link_t uih_link; |
|
futex_t lock; |
dev_handle_t dev_handle; |
fs_index_t index; |
/** |
* Parent node's first cluster. |
* Zero is used if this node is not linked, in which case nodep must |
* contain a pointer to the in-core node structure. |
* One is used when the parent is the root directory. |
*/ |
fat_cluster_t pfc; |
/** Directory entry index within the parent node. */ |
unsigned pdi; |
/** Pointer to in-core node instance. */ |
struct fat_node *nodep; |
} fat_idx_t; |
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/** FAT in-core node. */ |
typedef struct fat_node { |
futex_t lock; |
fat_node_type_t type; |
fat_idx_t *idx; |
/** |
* Node's first cluster. |
* Zero is used for zero-length nodes. |
* One is used to mark root directory. |
*/ |
fat_cluster_t firstc; |
/** FAT in-core node free list link. */ |
link_t ffn_link; |
size_t size; |
unsigned lnkcnt; |
unsigned refcnt; |
bool dirty; |
} fat_node_t; |
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extern fs_reg_t fat_reg; |
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extern void fat_mounted(ipc_callid_t, ipc_call_t *); |
extern void fat_mount(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 *); |
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extern fat_idx_t *fat_idx_get_by_pos(dev_handle_t, fat_cluster_t, unsigned); |
extern fat_idx_t *fat_idx_get_by_index(dev_handle_t, fs_index_t); |
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extern int fat_idx_init(void); |
extern void fat_idx_fini(void); |
extern int fat_idx_init_by_dev_handle(dev_handle_t); |
extern void fat_idx_fini_by_dev_handle(dev_handle_t); |
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#endif |
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/** |