X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=fs%2Fbattfs.h;h=0456fcfb6a841388d16a37dc7d83a45343cd030a;hb=1ab5fa0763879ab997884c8bc88631b69205a191;hp=455b21ce0c20c1a6e4bd521a5281936e6a714048;hpb=cdb8d4971e88e20148e080df14e99726c4d413b3;p=bertos.git diff --git a/fs/battfs.h b/fs/battfs.h index 455b21ce..0456fcfb 100644 --- a/fs/battfs.h +++ b/fs/battfs.h @@ -30,7 +30,7 @@ * * --> * - * \version $Id:$ + * \version $Id$ * * \author Francesco Sacchi * @@ -44,53 +44,91 @@ #include // uintXX_t; STATIC_ASSERT #include // CPU_BITS_PER_CHAR #include +#include +#include -typedef uint16_t fill_t; -typedef fill_t pgaddr_t; -typedef uint16_t pgoff_t; -typedef pgoff_t mark_t; -typedef uint8_t inode_t; -typedef uint8_t seq_t; -typedef rotating_t fcs_t; +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 rotating_t fcs_t; ///< Type for header FCS. /** - * BattFS page header. - * \note fields order is chosen to comply - * with CPU alignment. + * 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 + * header in memory. + * To see how this is stored on disk: + * \see battfs_to_disk + * \see disk_to_battfs */ typedef struct BattFsPageHeader { inode_t inode; ///< File inode (file identifier). seq_t seq; ///< Page sequence number. - mark_t mark; ///< Marker used to keep trace of free/used pages. - pgoff_t pgoff; ///< Page offset inside file. fill_t fill; ///< Filled bytes in page. - uint16_t rfu; ///< Reserved for future use, 0xFFFF for now. + 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. + */ + fcs_t fcs_free; /** * FCS (Frame Check Sequence) of the page header. - * \note This field must be the last one! - * This is needed because if the page is only partially - * written, we can use this to detect it. */ fcs_t fcs; } BattFsPageHeader; +/** + * Size of the header once saved on disk. + * \see battfs_to_disk + * \see disk_to_battfs + */ +#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 MAX_PAGE_ADDR ((1 << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t))) - 1) + /** * Max number of files. */ #define BATTFS_MAX_FILES (1 << (CPU_BITS_PER_CHAR * sizeof(inode_t))) -/* Ensure structure has no padding added */ -STATIC_ASSERT(sizeof(BattFsPageHeader) == 12); - /* Fwd decl */ struct BattFsSuper; /** - * Type for disk page addressing. + * Sentinel used to keep trace of unset pages in disk->page_array. */ -typedef uint16_t pgcnt_t; +#define PAGE_UNSET_SENTINEL ((1 << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t))) - 1) /** * Type interface for disk init function. @@ -112,7 +150,7 @@ typedef size_t (*disk_page_read_t) (struct BattFsSuper *d, pgcnt_t page, pgaddr_ * \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, void *buf, size_t); +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. @@ -153,14 +191,69 @@ typedef struct BattFsSuper * Is used by the filesystem to represent * the entire disk in memory. */ - pgcnt_t *page_array; + 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. + */ + mark_t free_next; 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. + List file_opened_list; ///< List used to keep trace of open files. /* 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. + +/** + * Modes for battfs_fileopen. + * \{ + */ +#define BATTFS_CREATE BV(0) ///< Create file if does not exist +#define BATTFS_RD BV(1) ///< Open file for reading +#define BATTFS_WR BV(2) ///< Open file fir writing +/*/}*/ + + +/** + * Describe a BattFs file usign a KFile. + */ +typedef struct KFileBattFs +{ + KFile fd; ///< KFile context + Node link; ///< Link for inserting in opened file list + inode_t inode; ///< inode of the opened file + BattFsSuper *disk; ///< Disk context + filemode_t mode; ///< File open mode + pgcnt_t *start; ///< Pointer to page_array file start position. +} KFileBattFs; + +/** + * Macro used to cast a KFile to a KFileBattFs. + * Also perform dynamic type check. + */ +INLINE KFileBattFs * KFILEBATTFS(KFile *fd) +{ + ASSERT(fd->_type == KFT_BATTFS); + return (KFileBattFs *)fd; +} + bool battfs_init(struct BattFsSuper *d); +bool battfs_close(struct BattFsSuper *disk); + +bool battfs_fileExists(BattFsSuper *disk, inode_t inode); +bool battfs_fileopen(BattFsSuper *disk, KFileBattFs *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); #endif /* FS_BATTFS_H */