static int journal_erase_segment(struct logfs_area *area)
{
struct super_block *sb = area->a_sb;
union {
struct logfs_segment_header sh;
unsigned char c[ALIGN(sizeof(struct logfs_segment_header), 16)];
} u;
u64 ofs;
int err;
err = logfs_erase_segment(sb, area->a_segno, 1);
if (err)
return err;
memset(&u, 0, sizeof(u));
u.sh.pad = 0;
u.sh.type = SEG_JOURNAL;
u.sh.level = 0;
u.sh.segno = cpu_to_be32(area->a_segno);
u.sh.ec = cpu_to_be32(area->a_erase_count);
u.sh.gec = cpu_to_be64(logfs_super(sb)->s_gec);
u.sh.crc = logfs_crc32(&u.sh, sizeof(u.sh), 4);
ofs = dev_ofs(sb, area->a_segno, 0);
area->a_used_bytes = sizeof(u);
logfs_buf_write(area, ofs, &u, sizeof(u));
return 0;
}
static int journal_erase_segment(struct logfs_area *area)
{
struct super_block *sb = area->a_sb;
struct logfs_segment_header sh;
u64 ofs;
int err;
err = logfs_erase_segment(sb, area->a_segno, 1);
if (err)
return err;
sh.pad = 0;
sh.type = SEG_JOURNAL;
sh.level = 0;
sh.segno = cpu_to_be32(area->a_segno);
sh.ec = cpu_to_be32(area->a_erase_count);
sh.gec = cpu_to_be64(logfs_super(sb)->s_gec);
sh.crc = logfs_crc32(&sh, sizeof(sh), 4);
/* This causes a bug in segment.c. Not yet. */
//logfs_set_segment_erased(sb, area->a_segno, area->a_erase_count, 0);
ofs = dev_ofs(sb, area->a_segno, 0);
area->a_used_bytes = ALIGN(sizeof(sh), 16);
logfs_buf_write(area, ofs, &sh, sizeof(sh));
return 0;
}
static int read_area(struct super_block *sb, struct logfs_je_area *a)
{
struct logfs_super *super = logfs_super(sb);
struct logfs_area *area = super->s_area[a->gc_level];
u64 ofs;
u32 writemask = ~(super->s_writesize - 1);
if (a->gc_level >= LOGFS_NO_AREAS)
return -EIO;
if (a->vim != VIM_DEFAULT)
return -EIO; /* TODO: close area and continue */
area->a_used_bytes = be32_to_cpu(a->used_bytes);
area->a_written_bytes = area->a_used_bytes & writemask;
area->a_segno = be32_to_cpu(a->segno);
if (area->a_segno)
area->a_is_open = 1;
ofs = dev_ofs(sb, area->a_segno, area->a_written_bytes);
if (super->s_writesize > 1)
logfs_buf_recover(area, ofs, a + 1, super->s_writesize);
else
logfs_buf_recover(area, ofs, NULL, 0);
return 0;
}
static s64 logfs_get_free_bytes(struct logfs_area *area, size_t bytes)
{
s32 ofs;
logfs_open_area(area, bytes);
ofs = area->a_used_bytes;
area->a_used_bytes += bytes;
BUG_ON(area->a_used_bytes >= logfs_super(area->a_sb)->s_segsize);
return dev_ofs(area->a_sb, area->a_segno, ofs);
}
static int logfs_read_segment(struct super_block *sb, u32 segno)
{
struct logfs_super *super = logfs_super(sb);
struct logfs_journal_header *jh = super->s_compressed_je;
u64 ofs, seg_ofs = dev_ofs(sb, segno, 0);
u32 h_ofs, last_ofs = 0;
u16 len, datalen, last_len = 0;
int i, err;
for (h_ofs = 0; h_ofs < super->s_segsize; h_ofs += sizeof(*jh)) {
ofs = seg_ofs + h_ofs;
err = __read_je_header(sb, ofs, jh);
if (err)
continue;
if (jh->h_type != cpu_to_be16(JE_COMMIT))
continue;
err = __read_je_payload(sb, ofs, jh);
if (err)
continue;
len = be16_to_cpu(jh->h_len);
datalen = be16_to_cpu(jh->h_datalen);
if ((datalen > sizeof(super->s_je_array)) ||
(datalen % sizeof(__be64)))
continue;
last_ofs = h_ofs;
last_len = datalen;
h_ofs += ALIGN(len, sizeof(*jh)) - sizeof(*jh);
}
if (last_ofs == 0)
return -ENOENT;
ofs = seg_ofs + last_ofs;
log_journal("Read commit from %llx\n", ofs);
err = __read_je(sb, ofs, jh);
BUG_ON(err);
if (err)
return err;
unpack(jh, super->s_je_array);
super->s_no_je = last_len / sizeof(__be64);
for (i = 0; i < super->s_no_je; i++) {
err = read_je(sb, be64_to_cpu(super->s_je_array[i]));
if (err)
return err;
}
super->s_journal_area->a_segno = segno;
return 0;
}
static u64 read_gec(struct super_block *sb, u32 segno)
{
struct logfs_segment_header sh;
__be32 crc;
int err;
if (!segno)
return 0;
err = wbuf_read(sb, dev_ofs(sb, segno, 0), sizeof(sh), &sh);
if (err)
return 0;
crc = logfs_crc32(&sh, sizeof(sh), 4);
if (crc != sh.crc) {
WARN_ON(sh.gec != cpu_to_be64(0xffffffffffffffffull));
return 0;
}
return be64_to_cpu(sh.gec);
}
static void write_wbuf(struct super_block *sb, struct logfs_area *area,
void *wbuf)
{
struct logfs_super *super = logfs_super(sb);
struct address_space *mapping = super->s_mapping_inode->i_mapping;
u64 ofs;
pgoff_t index;
int page_ofs;
struct page *page;
ofs = dev_ofs(sb, area->a_segno,
area->a_used_bytes & ~(super->s_writesize - 1));
index = ofs >> PAGE_SHIFT;
page_ofs = ofs & (PAGE_SIZE - 1);
page = find_lock_page(mapping, index);
BUG_ON(!page);
memcpy(wbuf, page_address(page) + page_ofs, super->s_writesize);
unlock_page(page);
}
static s64 logfs_get_free_bytes(struct logfs_area *area, size_t *bytes,
int must_pad)
{
u32 writesize = logfs_super(area->a_sb)->s_writesize;
s32 ofs;
int ret;
ret = logfs_open_area(area, *bytes);
if (ret)
return -EAGAIN;
ofs = area->a_used_bytes;
area->a_used_bytes += *bytes;
if (must_pad) {
area->a_used_bytes = ALIGN(area->a_used_bytes, writesize);
*bytes = area->a_used_bytes - ofs;
}
return dev_ofs(area->a_sb, area->a_segno, ofs);
}
