From e483f335ce4479370bc9fbd6d1cfc7e369437132 Mon Sep 17 00:00:00 2001 From: nvt-se Date: Mon, 25 Aug 2008 09:57:38 +0000 Subject: [PATCH] activated EOF hints and fixed a bug in the garbage collector. --- core/cfs/cfs-coffee.c | 222 ++++++++++++++++++++++++++---------------- 1 file changed, 140 insertions(+), 82 deletions(-) diff --git a/core/cfs/cfs-coffee.c b/core/cfs/cfs-coffee.c index 30798c0f3..62225dc82 100644 --- a/core/cfs/cfs-coffee.c +++ b/core/cfs/cfs-coffee.c @@ -43,6 +43,7 @@ #include "cfs/cfs-coffee.h" #include "dev/watchdog.h" +#include #include #define DEBUG 0 @@ -66,36 +67,38 @@ #define COFFEE_FD_APPEND 0x4 #define COFFEE_FD_FREE 0x0 -#define COFFEE_PAGE_COUNT (COFFEE_SIZE / COFFEE_PAGE_SIZE) -#define COFFEE_PAGES_PER_SECTOR (COFFEE_SECTOR_SIZE / COFFEE_PAGE_SIZE) - -#define COFFEE_FLAG_VALID 0x1 -#define COFFEE_FLAG_ALLOCATED 0x2 -#define COFFEE_FLAG_OBSOLETE 0x4 -#define COFFEE_FLAG_MODIFIED 0x8 -#define COFFEE_FLAG_LOG 0x10 - -#define LOG_CMD_MAGIC 0x7a - -#define COFFEE_PAGE_ALLOCATED(hdr) ((hdr).flags & COFFEE_FLAG_ALLOCATED) -#define COFFEE_PAGE_FREE(hdr) !COFFEE_PAGE_ALLOCATED(hdr) -#define COFFEE_PAGE_OBSOLETE(hdr) ((hdr).flags & COFFEE_FLAG_OBSOLETE) -#define COFFEE_PAGE_ACTIVE(hdr) \ - (COFFEE_PAGE_ALLOCATED(hdr) && !COFFEE_PAGE_OBSOLETE(hdr)) -#define COFFEE_PAGE_LOG(hdr) ((hdr).flags & COFFEE_FLAG_LOG) -#define COFFEE_PAGE_MODIFIED(hdr) ((hdr).flags & COFFEE_FLAG_MODIFIED) - -#define FD_VALID(fd) \ - ((fd) < COFFEE_FD_SET_SIZE && coffee_fd_set[(fd)].flags != COFFEE_FD_FREE) +#define FD_VALID(fd) \ + ((fd) < COFFEE_FD_SET_SIZE && \ + coffee_fd_set[(fd)].flags != COFFEE_FD_FREE) #define FD_READABLE(fd) (coffee_fd_set[(fd)].flags & CFS_READ) #define FD_WRITABLE(fd) (coffee_fd_set[(fd)].flags & CFS_WRITE) #define FD_APPENDABLE(fd) (coffee_fd_set[(fd)].flags & CFS_APPEND) -#define READ_HEADER(hdr, page) \ - COFFEE_READ((hdr), sizeof (*hdr), (page) * COFFEE_PAGE_SIZE) +/* File header flags. */ +#define COFFEE_FLAG_VALID 0x1 /* Completely written header. */ +#define COFFEE_FLAG_ALLOCATED 0x2 /* Allocated file. */ +#define COFFEE_FLAG_OBSOLETE 0x4 /* File marked for GC. */ +#define COFFEE_FLAG_MODIFIED 0x8 /* Modified file, log exists. */ +#define COFFEE_FLAG_LOG 0x10 /* Log file. */ +#define COFFEE_FLAG_ISOLATED 0x20 /* Isolated page. */ +#define COFFEE_PAGE_ALLOCATED(hdr) ((hdr).flags & COFFEE_FLAG_ALLOCATED) +#define COFFEE_PAGE_FREE(hdr) !COFFEE_PAGE_ALLOCATED(hdr) +#define COFFEE_PAGE_LOG(hdr) ((hdr).flags & COFFEE_FLAG_LOG) +#define COFFEE_PAGE_MODIFIED(hdr) ((hdr).flags & COFFEE_FLAG_MODIFIED) +#define COFFEE_PAGE_ISOLATED(hdr) ((hdr).flags & COFFEE_FLAG_ISOLATED) +#define COFFEE_PAGE_OBSOLETE(hdr) ((hdr).flags & COFFEE_FLAG_OBSOLETE) +#define COFFEE_PAGE_ACTIVE(hdr) (COFFEE_PAGE_ALLOCATED(hdr) && \ + !COFFEE_PAGE_OBSOLETE(hdr) && \ + !COFFEE_PAGE_ISOLATED(hdr)) + +#define COFFEE_PAGE_COUNT (COFFEE_SIZE / COFFEE_PAGE_SIZE) +#define COFFEE_PAGES_PER_SECTOR (COFFEE_SECTOR_SIZE / COFFEE_PAGE_SIZE) + +#define READ_HEADER(hdr, page) \ + COFFEE_READ((hdr), sizeof(*hdr), (page) * COFFEE_PAGE_SIZE) #define WRITE_HEADER(hdr, page) \ - COFFEE_WRITE((hdr), sizeof (*hdr), (page) * COFFEE_PAGE_SIZE) + COFFEE_WRITE((hdr), sizeof(*hdr), (page) * COFFEE_PAGE_SIZE) struct file_desc { uint32_t offset; @@ -130,7 +133,7 @@ struct log_param { #define ABS_OFFSET(file_page, file_offset) \ ((file_page) * COFFEE_PAGE_SIZE + \ - sizeof (struct file_header) + (file_offset)) + sizeof(struct file_header) + (file_offset)) static struct dir_cache dir_cache[COFFEE_DIR_CACHE_ENTRIES]; static struct file_desc coffee_fd_set[COFFEE_FD_SET_SIZE]; @@ -139,11 +142,12 @@ static struct file_desc coffee_fd_set[COFFEE_FD_SET_SIZE]; static void get_sector_status(uint16_t sector, uint16_t *active, uint16_t *free, uint16_t *obsolete) { - uint32_t offset; + uint32_t offset, sector_start; uint32_t end; struct file_header hdr; static int16_t skip_pages; static int last_pages_are_active; + int i; *active = *free = *obsolete = 0; if(sector == 0) { @@ -158,17 +162,32 @@ get_sector_status(uint16_t sector, uint16_t *active, } return; } - + + sector_start = sector * COFFEE_SECTOR_SIZE; + if(last_pages_are_active) { *active = skip_pages; } else { *obsolete = skip_pages; + + /* Split an obsolete file starting in the previous sector and mark + the following pages as isolated. */ + offset = sector_start; + for(i = 0; i < skip_pages; i++) { + COFFEE_READ(&hdr, sizeof(hdr), offset); + hdr.flags |= COFFEE_FLAG_ISOLATED; + COFFEE_WRITE(&hdr, sizeof(hdr), offset); + offset += COFFEE_PAGE_SIZE; + } + PRINTF("Coffee: Isolated %u pages starting in sector %d\n", + (unsigned)skip_pages, (int)sector); } - offset = sector * COFFEE_SECTOR_SIZE + skip_pages * COFFEE_PAGE_SIZE; + + offset = sector_start + skip_pages * COFFEE_PAGE_SIZE; end = (sector + 1) * COFFEE_SECTOR_SIZE; while(offset < end) { - COFFEE_READ(&hdr, sizeof (hdr), offset); + COFFEE_READ(&hdr, sizeof(hdr), offset); if(COFFEE_PAGE_ACTIVE(hdr)) { last_pages_are_active = 1; offset += hdr.max_pages * COFFEE_PAGE_SIZE; @@ -177,6 +196,10 @@ get_sector_status(uint16_t sector, uint16_t *active, last_pages_are_active = 0; offset += hdr.max_pages * COFFEE_PAGE_SIZE; *obsolete += hdr.max_pages; + } else if(COFFEE_PAGE_ISOLATED(hdr)) { + last_pages_are_active = 0; + offset += COFFEE_PAGE_SIZE; + *obsolete++; } else if(COFFEE_PAGE_FREE(hdr)) { *free = (end - offset) / COFFEE_PAGE_SIZE; break; @@ -262,6 +285,8 @@ find_file(const char *name) page += hdr.max_pages; } else if(COFFEE_PAGE_OBSOLETE(hdr)) { page += hdr.max_pages; + } else if(COFFEE_PAGE_ISOLATED(hdr)) { + ++page; } else { /* It follows from the properties of the page allocation algorithm that if a free page is encountered, then the rest of the sector @@ -281,26 +306,39 @@ find_offset_in_file(int first_page) unsigned char buf[COFFEE_PAGE_SIZE]; int page; int i; - + int search_limit, range_start, range_end, part_size; + READ_HEADER(&hdr, first_page); - + for(search_limit = i = 0; i < sizeof(hdr.eof_hint) * CHAR_BIT; i++) { + if(hdr.eof_hint >> i) { + search_limit = i + 1; + } + } + part_size = hdr.max_pages / (sizeof(hdr.eof_hint) * CHAR_BIT); + range_start = part_size * search_limit; + range_end = range_start + part_size; + + if(range_end > hdr.max_pages) { + range_end = hdr.max_pages; + } + /* - * Move from the end of the file towards the beginning and look for + * Move from the end of the range towards the beginning and look for * a byte that has been modified. * * An important implication of this is that if the last written bytes * are zeroes, then these are skipped from the calculation. */ - for(page = first_page + hdr.max_pages - 1; page >= first_page; page--) { + for(page = first_page + range_end; page >= first_page + range_start; page--) { watchdog_periodic(); - COFFEE_READ(buf, sizeof (buf), page * COFFEE_PAGE_SIZE); + COFFEE_READ(buf, sizeof(buf), page * COFFEE_PAGE_SIZE); for(i = COFFEE_PAGE_SIZE - 1; i >= 0; i--) { if(buf[i] != 0) { if(page == first_page) { - return i < sizeof (hdr) ? 0 : 1 + i - sizeof (hdr); + return i < sizeof(hdr) ? 0 : 1 + i - sizeof(hdr); } else { - return 1 + i + (page - first_page) * COFFEE_PAGE_SIZE - sizeof (hdr); + return 1 + i + (page - first_page) * COFFEE_PAGE_SIZE - sizeof(hdr); } } } @@ -329,6 +367,8 @@ find_contiguous_pages(unsigned wanted) } /* Jump to the next sector. */ page = (page + COFFEE_PAGES_PER_SECTOR) & ~(COFFEE_PAGES_PER_SECTOR - 1); + } else if(COFFEE_PAGE_ISOLATED(hdr)) { + ++page; } else { start = -1; page += hdr.max_pages; @@ -361,21 +401,17 @@ cfs_garbage_collect(void) COFFEE_ERASE(sector); PRINTF("Coffee: Erased sector %d!\n", sector); ++sectors_in_row; - } else { if(sectors_in_row > longest_row) { longest_row = sectors_in_row; } + } else { sectors_in_row = 0; } } - if(sectors_in_row > longest_row) { - longest_row = sectors_in_row; - } - watchdog_start(); - return longest_row * (COFFEE_PAGES_PER_SECTOR); + return longest_row * COFFEE_PAGES_PER_SECTOR; } /*---------------------------------------------------------------------------*/ static int @@ -449,7 +485,7 @@ read_log_page(struct file_header *hdr, int16_t last_entry, struct log_param *lp) uint16_t processed; uint16_t current_batch_size; - base = ABS_OFFSET(hdr->log_page, sizeof (indices[0]) * search_entries); + base = ABS_OFFSET(hdr->log_page, sizeof(indices[0]) * search_entries); processed = 0; match_index = -1; while(processed < search_entries && match_index < 0) { @@ -459,8 +495,8 @@ read_log_page(struct file_header *hdr, int16_t last_entry, struct log_param *lp) current_batch_size = entry_count; } - base -= current_batch_size * sizeof (indices[0]); - COFFEE_READ(&indices, sizeof (indices[0]) * current_batch_size, base); + base -= current_batch_size * sizeof(indices[0]); + COFFEE_READ(&indices, sizeof(indices[0]) * current_batch_size, base); for(i = current_batch_size - 1; i >= 0; i--) { if(indices[i] - 1 == page) { @@ -476,7 +512,7 @@ read_log_page(struct file_header *hdr, int16_t last_entry, struct log_param *lp) } base = hdr->log_page * COFFEE_PAGE_SIZE; - base += sizeof (struct file_header) + log_entries * sizeof (page); + base += sizeof(struct file_header) + log_entries * sizeof(page); base += (unsigned long)match_index * log_entry_size; base += lp->offset; @@ -493,11 +529,11 @@ create_log_name(unsigned char *new, int max_size, unsigned char *old) int len; len = strlen(old); - if(len > max_size - sizeof (suffix)) { - len = max_size - sizeof (suffix); + if(len > max_size - sizeof(suffix)) { + len = max_size - sizeof(suffix); } memcpy(new, old, len); - memcpy(&new[len], suffix, sizeof (suffix)); + memcpy(&new[len], suffix, sizeof(suffix)); return new; } @@ -506,7 +542,7 @@ static int16_t create_log(int16_t file_page, struct file_header *hdr) { int16_t log_page; - unsigned char log_name[sizeof (hdr->name)]; + unsigned char log_name[sizeof(hdr->name)]; uint16_t log_entry_size, log_entries; uint32_t size; @@ -514,10 +550,10 @@ create_log(int16_t file_page, struct file_header *hdr) COFFEE_PAGE_SIZE : hdr->log_entry_size; log_entries = hdr->log_entries == 0 ? COFFEE_LOG_SIZE / log_entry_size : hdr->log_entries; - - size = log_entries * sizeof (uint16_t); + + size = log_entries * sizeof(uint16_t); size += log_entries * log_entry_size; - log_page = cfs_coffee_reserve(create_log_name(log_name, sizeof (log_name), hdr->name), + log_page = cfs_coffee_reserve(create_log_name(log_name, sizeof(log_name), hdr->name), size); if(log_page < 0) { return -1; @@ -539,14 +575,14 @@ flush_log(uint16_t file_page) int fd, n; char buf[64]; int32_t offset; - + READ_HEADER(&hdr, file_page); log_page = hdr.log_page; fd = cfs_open(hdr.name, CFS_READ); if(fd < 0) { return -1; } - + new_file_page = cfs_coffee_reserve(hdr.name, hdr.max_pages * COFFEE_PAGE_SIZE); if(new_file_page < 0) { @@ -556,7 +592,7 @@ flush_log(uint16_t file_page) offset = 0; do { watchdog_periodic(); - n = cfs_read(fd, buf, sizeof (buf)); + n = cfs_read(fd, buf, sizeof(buf)); if(n < 0) { remove_by_page(new_file_page, 0, 0); cfs_close(fd); @@ -637,8 +673,8 @@ write_log_page(struct file_desc *fdp, struct log_param *lp) for(processed = 0; processed < log_entries;) { current_batch_size = log_entries - processed >= entry_count ? entry_count : log_entries - processed; - COFFEE_READ(&indices, current_batch_size * sizeof (indices[0]), - ABS_OFFSET(log_page, processed * sizeof (indices[0]))); + COFFEE_READ(&indices, current_batch_size * sizeof(indices[0]), + ABS_OFFSET(log_page, processed * sizeof(indices[0]))); for(i = 0; i < current_batch_size && indices[i] != 0; i++); log_entry = i; if(log_entry < current_batch_size) { @@ -653,7 +689,7 @@ write_log_page(struct file_desc *fdp, struct log_param *lp) if(log_entry >= log_entries) { /* The log is full. The new file should be written out. */ - PRINTF("Coffee: The log for file %s is full\n", hdr.name); + PRINTF("Coffee: Flushing the log for file %s\n", hdr.name); fdp->next_log_entry = 0; return flush_log(fdp->file_page); } @@ -678,21 +714,21 @@ write_log_page(struct file_desc *fdp, struct log_param *lp) if(lp->offset > 0 && read_log_page(&hdr, fdp->next_log_entry > 0 ? fdp->next_log_entry - 1 : -1, &lp_out) < 0) { - COFFEE_READ(copy_buf, sizeof (copy_buf), + COFFEE_READ(copy_buf, sizeof(copy_buf), ABS_OFFSET(fdp->file_page, page * log_entry_size)); } memcpy((char *) ©_buf + lp->offset, lp->buf, lp->size); base = (unsigned long)log_page * COFFEE_PAGE_SIZE; - base += sizeof (hdr); - base += log_entries * sizeof (page); + base += sizeof(hdr); + base += log_entries * sizeof(page); base += (unsigned long)log_entry * log_entry_size; - COFFEE_WRITE(copy_buf, sizeof (copy_buf), base); + COFFEE_WRITE(copy_buf, sizeof(copy_buf), base); ++page; - COFFEE_WRITE(&page, sizeof (page), - ABS_OFFSET(log_page, log_entry * sizeof (page))); + COFFEE_WRITE(&page, sizeof(page), + ABS_OFFSET(log_page, log_entry * sizeof(page))); fdp->next_log_entry = log_entry + 1; } @@ -732,7 +768,8 @@ cfs_open(const char *name, int flags) if((page = cfs_coffee_reserve(name, COFFEE_DYN_SIZE)) < 0) { return -1; } - coffee_fd_set[fd].max_pages = COFFEE_DYN_SIZE / COFFEE_PAGE_SIZE; + coffee_fd_set[fd].max_pages = (COFFEE_DYN_SIZE + sizeof(hdr) + + COFFEE_PAGE_SIZE - 1) / COFFEE_PAGE_SIZE; } else { READ_HEADER(&hdr, page); coffee_fd_set[fd].max_pages = hdr.max_pages; @@ -750,7 +787,25 @@ cfs_open(const char *name, int flags) void cfs_close(int fd) { + struct file_header hdr; + uint16_t current_page, i; + int part_size; + uint8_t eof_hint; + if(FD_VALID(fd)) { + READ_HEADER(&hdr, coffee_fd_set[fd].file_page); + current_page = (coffee_fd_set[fd].end + COFFEE_PAGE_SIZE - 1) / COFFEE_PAGE_SIZE; + part_size = hdr.max_pages / (sizeof(hdr.eof_hint) * CHAR_BIT); + + for(i = eof_hint = 0; i < sizeof(eof_hint) * CHAR_BIT; i++) { + eof_hint |= (current_page > (i + 1) * part_size) << i; + } + + if(eof_hint > hdr.eof_hint) { + hdr.eof_hint |= eof_hint; + WRITE_HEADER(&hdr, coffee_fd_set[fd].file_page); + } + coffee_fd_set[fd].flags = COFFEE_FD_FREE; } } @@ -765,7 +820,7 @@ cfs_seek(int fd, unsigned offset) } READ_HEADER(&hdr, coffee_fd_set[fd].file_page); - if(sizeof (hdr) + offset >= hdr.max_pages * COFFEE_PAGE_SIZE) { + if(sizeof(hdr) + offset >= hdr.max_pages * COFFEE_PAGE_SIZE) { /* XXX: Try to extend the file here? */ return -1; } @@ -857,10 +912,10 @@ cfs_write(int fd, const void *buf, unsigned size) fdp = &coffee_fd_set[fd]; - if(size + fdp->offset + sizeof (struct file_header) > + if(size + fdp->offset + sizeof(struct file_header) > fdp->max_pages * COFFEE_PAGE_SIZE) { size = fdp->max_pages * COFFEE_PAGE_SIZE - - fdp->offset - sizeof (struct file_header); + fdp->offset - sizeof(struct file_header); } if(fdp->offset < fdp->end) { @@ -918,16 +973,19 @@ cfs_readdir(struct cfs_dir *dir, struct cfs_dirent *entry) for(page = *(uint16_t *)dir->dummy_space; page < COFFEE_PAGE_COUNT;) { watchdog_periodic(); READ_HEADER(&hdr, page); - if(COFFEE_PAGE_ACTIVE(hdr) && !COFFEE_PAGE_LOG(hdr)) { - memcpy(entry->name, hdr.name, sizeof (entry->name)); - entry->name[sizeof (entry->name) - 1] = '\0'; - entry->size = find_offset_in_file(page); - page += hdr.max_pages; - *(uint16_t *)dir->dummy_space = page; - return 0; - } else if (COFFEE_PAGE_FREE(hdr)) { + if(COFFEE_PAGE_FREE(hdr)) { page = (page + COFFEE_PAGES_PER_SECTOR) & ~(COFFEE_PAGES_PER_SECTOR - 1); + } else if(COFFEE_PAGE_ISOLATED(hdr)) { + ++page; } else { + if(COFFEE_PAGE_ACTIVE(hdr) && !COFFEE_PAGE_LOG(hdr)) { + memcpy(entry->name, hdr.name, sizeof(entry->name)); + entry->name[sizeof(entry->name) - 1] = '\0'; + entry->size = find_offset_in_file(page); + *(uint16_t *)dir->dummy_space = page; + page += hdr.max_pages; + return 0; + } page += hdr.max_pages; } } @@ -948,7 +1006,7 @@ cfs_coffee_reserve(const char *name, uint32_t size) unsigned need_pages; int page; - need_pages = (size + sizeof (hdr) + COFFEE_PAGE_SIZE - 1) / COFFEE_PAGE_SIZE; + need_pages = (size + sizeof(hdr) + COFFEE_PAGE_SIZE - 1) / COFFEE_PAGE_SIZE; watchdog_stop(); page = find_contiguous_pages(need_pages); @@ -963,8 +1021,8 @@ cfs_coffee_reserve(const char *name, uint32_t size) } } - memcpy(hdr.name, name, sizeof (hdr.name)); - hdr.name[sizeof (hdr.name) - 1] = '\0'; + memcpy(hdr.name, name, sizeof(hdr.name)); + hdr.name[sizeof(hdr.name) - 1] = '\0'; hdr.max_pages = need_pages; hdr.flags = COFFEE_FLAG_ALLOCATED | COFFEE_FLAG_VALID; hdr.log_page = 0; @@ -1014,14 +1072,14 @@ cfs_coffee_format(void) nsectors = COFFEE_SIZE / COFFEE_SECTOR_SIZE; /* Reject format requests when the configuration is incorrect. */ - if (nsectors < 1 || (COFFEE_START & (COFFEE_SECTOR_SIZE - 1))) { + if(nsectors < 1 || (COFFEE_START & (COFFEE_SECTOR_SIZE - 1))) { return -1; } PRINTF("Coffee: Formatting %d sectors", nsectors); watchdog_stop(); - for (i = 0; i < nsectors; i++) { + for(i = 0; i < nsectors; i++) { COFFEE_ERASE(i); PRINTF("."); }