*
* \brief BattFS: a filesystem for embedded platforms (interface).
* TODO: Add detailed filesystem description.
+ *
+ * $WIZ$ module_name = "battfs"
+ * $WIZ$ module_depends = "rotating_hash", "kfile"
+ * $WIZ$ module_configuration = "bertos/cfg/cfg_battfs.h"
*/
#ifndef FS_BATTFS_H
#include <cfg/compiler.h> // uintXX_t; STATIC_ASSERT
#include <cpu/types.h> // CPU_BITS_PER_CHAR
#include <algo/rotating_hash.h>
-#include <mware/list.h>
-#include <kern/kfile.h>
+#include <struct/list.h>
+#include <io/kfile.h>
+#include <io/kblock.h>
typedef uint16_t fill_t; ///< Type for keeping trace of space filled inside a page
typedef fill_t pgaddr_t; ///< Type for addressing space inside a page
typedef uint16_t pgcnt_t; ///< Type for counting pages on disk
typedef pgcnt_t pgoff_t; ///< Type for counting pages inside a file
-typedef uint32_t mark_t; ///< Type for marking pages as free
typedef uint8_t inode_t; ///< Type for file inodes
-typedef uint8_t seq_t; ///< Type for page seq number
+typedef uint64_t seq_t; ///< Type for page seq number, at least 40bits wide.
typedef rotating_t fcs_t; ///< Type for header FCS.
-/**
- * Size required for free block allocation is at least 1 bit more
- * than page addressing.
- */
-STATIC_ASSERT(sizeof(mark_t) > sizeof(pgcnt_t));
/**
* BattFS page header, used to represent a page
typedef struct BattFsPageHeader
{
inode_t inode; ///< File inode (file identifier).
- seq_t seq; ///< Page sequence number.
fill_t fill; ///< Filled bytes in page.
pgoff_t pgoff; ///< Page offset inside file.
- mark_t mark; ///< Marker used to keep trace of free/used pages.
/**
- * FCS (Frame Check Sequence) of the page header once the page
- * as been marked as free.
+ * Page sequence number.
+ * Every time a page is rewritten the seq number is
+ * increased by 1. seq_t is wide enough to not to perform
+ * a wrap around before the memory death.
+ * So it can be kept as it would be
+ * monotonically increasing for our needs.
*/
- fcs_t fcs_free;
+ seq_t seq;
/**
* FCS (Frame Check Sequence) of the page header.
*/
#define BATTFS_HEADER_LEN 12
-/**
- * Marks for valid pages.
- * Simply set to 1 all field bits.
- * \{
- */
-#define MARK_PAGE_VALID ((1 << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t) + 1)) - 1)
-#define FCS_FREE_VALID ((1 << (CPU_BITS_PER_CHAR * sizeof(fcs_t))) - 1)
-/* \} */
-
-
-/**
- * Half-size of free page marker.
- * Used to keep trace of free marker wrap-arounds.
- */
-#define MARK_HALF_SIZE (1 << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t) + 1))
-
/**
* Maximum page address.
*/
*/
#define BATTFS_MAX_FILES (1 << (CPU_BITS_PER_CHAR * sizeof(inode_t)))
-/* Fwd decl */
-struct BattFsSuper;
-
/**
* Sentinel used to keep trace of unset pages in disk->page_array.
*/
-#define PAGE_UNSET_SENTINEL ((1 << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t))) - 1)
-
-/**
- * Type interface for disk init function.
- * \return true if all is ok, false otherwise.
- */
-typedef bool (*disk_open_t) (struct BattFsSuper *d);
-
-/**
- * Type interface for disk page read function.
- * \a page is the page address, \a addr the address inside the page,
- * \a size the lenght to be read.
- * \return the number of bytes read.
- */
-typedef size_t (*disk_page_read_t) (struct BattFsSuper *d, pgcnt_t page, pgaddr_t addr, void *buf, size_t);
-
-/**
- * Type interface for disk page write function.
- * \a page is the page address, \a addr the address inside the page,
- * \a size the lenght to be written.
- * \return the number of bytes written.
- */
-typedef size_t (*disk_page_write_t) (struct BattFsSuper *d, pgcnt_t page, pgaddr_t addr, const void *buf, size_t);
-
-/**
- * Type interface for disk page erase function.
- * \a page is the page address.
- * \return true if all is ok, false otherwise.
- */
-typedef bool (*disk_page_erase_t) (struct BattFsSuper *d, pgcnt_t page);
-
-/**
- * Type interface for disk deinit function.
- * \return true if all is ok, false otherwise.
- */
-typedef bool (*disk_close_t) (struct BattFsSuper *d);
-
+#define PAGE_UNSET_SENTINEL ((pgcnt_t)((1L << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t))) - 1))
typedef uint32_t disk_size_t; ///< Type for disk sizes.
*/
typedef struct BattFsSuper
{
- disk_open_t open; ///< Disk init.
- disk_page_read_t read; ///< Page read.
- disk_page_write_t write; ///< Page write.
- disk_page_erase_t erase; ///< Page erase.
- disk_close_t close; ///< Disk deinit.
-
- pgaddr_t page_size; ///< Size of a disk page, in bytes.
- pgcnt_t page_count; ///< Number of pages on disk.
+ KBlock *dev; ///< Block device context (physical disk).
+ pgaddr_t data_size; ///< Size of space usable for data in a disk page, in bytes. The rest is used by the page header.
/**
* Page allocation array.
* This array must be allocated somewhere and
*/
pgcnt_t *page_array;
- /**
- * Lowest free page counter.
- * This is the counter of the first availble free page.
- */
- mark_t free_start;
-
- /**
- * Highest free page counter.
- * This value is the next to be used to mark a block as free.
+ /**
+ * Lowest address, in page array, for free pages.
+ * Pages above this element are free for use.
*/
- mark_t free_next;
+ pgcnt_t free_page_start;
disk_size_t disk_size; ///< Size of the disk, in bytes (page_count * page_size).
disk_size_t free_bytes; ///< Free space on the disk.
/* TODO add other fields. */
} BattFsSuper;
-typedef uint8_t filemode_t; ///< Type for file open modes.
-typedef uint32_t file_size_t; ///< Type for file sizes.
+/**
+ * True if space on \a disk is over.
+ */
+#define SPACE_OVER(disk) ((disk)->free_page_start >= (disk)->dev->blk_cnt)
+
+typedef uint8_t filemode_t; ///< Type for file open modes.
+typedef int32_t file_size_t; ///< Type for file sizes.
/**
* Modes for battfs_fileopen.
/*/}*/
+/**
+ * File errors.
+ * \{
+ */
+#define BATTFS_NEGATIVE_SEEK_ERR BV(0) ///< Trying to read/write before file start.
+#define BATTFS_DISK_READ_ERR BV(1) ///< Error reading from disk device.
+#define BATTFS_DISK_WRITE_ERR BV(2) ///< Error writing in the disk device.
+#define BATTFS_DISK_SPACEOVER_ERR BV(3) ///< No more disk space available.
+#define BATTFS_DISK_FLUSHBUF_ERR BV(4) ///< Error flushing (writing) the current page to disk.
+#define BATTFS_FILE_NOT_FOUND_ERR BV(5) ///< File not found on disk.
+/*/}*/
+
/**
* Describe a BattFs file usign a KFile.
*/
-typedef struct BattFsKFile
+typedef struct BattFs
{
KFile fd; ///< KFile context
Node link; ///< Link for inserting in opened file list
BattFsSuper *disk; ///< Disk context
filemode_t mode; ///< File open mode
pgcnt_t *start; ///< Pointer to page_array file start position.
-} BattFsKFile;
+ pgcnt_t max_off; ///< Max page offset allocated for the file.
+ int errors; ///< File status/errors
+} BattFs;
/**
* Id for battfs file descriptors.
#define KFT_BATTFS MAKE_ID('B', 'T', 'F', 'S')
/**
- * Macro used to cast a KFile to a BattFsKFile.
+ * Macro used to cast a KFile to a BattFS.
* Also perform dynamic type check.
*/
-INLINE BattFsKFile * BATTFSKFILE(KFile *fd)
+INLINE BattFs * BATTFS_CAST(KFile *fd)
{
ASSERT(fd->_type == KFT_BATTFS);
- return (BattFsKFile *)fd;
+ return (BattFs *)fd;
}
-bool battfs_init(struct BattFsSuper *d);
-bool battfs_close(struct BattFsSuper *disk);
+bool battfs_mount(struct BattFsSuper *disk, struct KBlock *dev, pgcnt_t *page_array, size_t array_size);
+bool battfs_fsck(struct BattFsSuper *disk);
+bool battfs_umount(struct BattFsSuper *disk);
bool battfs_fileExists(BattFsSuper *disk, inode_t inode);
-bool battfs_fileopen(BattFsSuper *disk, BattFsKFile *fd, inode_t inode, filemode_t mode);
-
-bool battfs_writeTestBlock(struct BattFsSuper *disk, pgcnt_t page, inode_t inode, seq_t seq, fill_t fill, pgoff_t pgoff, mark_t mark);
+bool battfs_fileopen(BattFsSuper *disk, BattFs *fd, inode_t inode, filemode_t mode);
+void battfs_writeTestBlock(KBlock *dev, pgcnt_t page, inode_t inode, seq_t seq, fill_t fill, pgoff_t pgoff);
+void battfs_eraseBlock(KBlock *dev, pgcnt_t page);
#endif /* FS_BATTFS_H */
projects / bertos.git / blobdiff