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activated EOF hints and fixed a bug in the garbage collector.

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This commit is contained in:
nvt-se 2008-08-25 09:57:38 +00:00
parent d28b27f031
commit e483f335ce
1 changed files with 140 additions and 82 deletions
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208
core/cfs/cfs-coffee.c
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@ -43,6 +43,7 @@
#include "cfs/cfs-coffee.h"
#include "dev/watchdog.h"
#include <limits.h>
#include <string.h>
#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)
((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) {
@ -159,16 +163,31 @@ 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;
}
offset = sector * COFFEE_SECTOR_SIZE + skip_pages * COFFEE_PAGE_SIZE;
PRINTF("Coffee: Isolated %u pages starting in sector %d\n",
(unsigned)skip_pages, (int)sector);
}
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;
@ -515,9 +551,9 @@ create_log(int16_t file_page, struct file_header *hdr)
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;
@ -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 *) &copy_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(".");
}