static inline int nilfs_cpfile_get_checkpoint_block(struct inode *cpfile,
__u64 cno,
int create,
struct buffer_head **bhp)
{
return nilfs_mdt_get_block(cpfile,
nilfs_cpfile_get_blkoff(cpfile, cno),
create, nilfs_cpfile_block_init, bhp);
}
/**
* nilfs_cpfile_find_checkpoint_block - find and get a buffer on cpfile
* @cpfile: inode of cpfile
* @start_cno: start checkpoint number (inclusive)
* @end_cno: end checkpoint number (inclusive)
* @cnop: place to store the next checkpoint number
* @bhp: place to store a pointer to buffer_head struct
*
* Return Value: On success, it returns 0. On error, the following negative
* error code is returned.
*
* %-ENOMEM - Insufficient memory available.
*
* %-EIO - I/O error
*
* %-ENOENT - no block exists in the range.
*/
static int nilfs_cpfile_find_checkpoint_block(struct inode *cpfile,
__u64 start_cno, __u64 end_cno,
__u64 *cnop,
struct buffer_head **bhp)
{
unsigned long start, end, blkoff;
int ret;
if (unlikely(start_cno > end_cno))
return -ENOENT;
start = nilfs_cpfile_get_blkoff(cpfile, start_cno);
end = nilfs_cpfile_get_blkoff(cpfile, end_cno);
ret = nilfs_mdt_find_block(cpfile, start, end, &blkoff, bhp);
if (!ret)
*cnop = (blkoff == start) ? start_cno :
nilfs_cpfile_first_checkpoint_in_block(cpfile, blkoff);
return ret;
}
static inline int nilfs_cpfile_is_in_first(const struct inode *cpfile,
__u64 cno)
{
return nilfs_cpfile_get_blkoff(cpfile, cno) == 0;
}
static inline int nilfs_cpfile_delete_checkpoint_block(struct inode *cpfile,
__u64 cno)
{
return nilfs_mdt_delete_block(cpfile,
nilfs_cpfile_get_blkoff(cpfile, cno));
}
static int nilfs_cpfile_set_snapshot(struct inode *cpfile, __u64 cno)
{
struct buffer_head *header_bh, *curr_bh, *prev_bh, *cp_bh;
struct nilfs_cpfile_header *header;
struct nilfs_checkpoint *cp;
struct nilfs_snapshot_list *list;
__u64 curr, prev;
unsigned long curr_blkoff, prev_blkoff;
void *kaddr;
int ret;
if (cno == 0)
return -ENOENT; /* checkpoint number 0 is invalid */
down_write(&NILFS_MDT(cpfile)->mi_sem);
ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
if (ret < 0)
goto out_sem;
kaddr = kmap_atomic(cp_bh->b_page);
cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
if (nilfs_checkpoint_invalid(cp)) {
ret = -ENOENT;
kunmap_atomic(kaddr);
goto out_cp;
}
if (nilfs_checkpoint_snapshot(cp)) {
ret = 0;
kunmap_atomic(kaddr);
goto out_cp;
}
kunmap_atomic(kaddr);
ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
if (ret < 0)
goto out_cp;
kaddr = kmap_atomic(header_bh->b_page);
header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
list = &header->ch_snapshot_list;
curr_bh = header_bh;
get_bh(curr_bh);
curr = 0;
curr_blkoff = 0;
prev = le64_to_cpu(list->ssl_prev);
while (prev > cno) {
prev_blkoff = nilfs_cpfile_get_blkoff(cpfile, prev);
curr = prev;
if (curr_blkoff != prev_blkoff) {
kunmap_atomic(kaddr);
brelse(curr_bh);
ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr,
0, &curr_bh);
if (ret < 0)
goto out_header;
kaddr = kmap_atomic(curr_bh->b_page);
}
curr_blkoff = prev_blkoff;
cp = nilfs_cpfile_block_get_checkpoint(
cpfile, curr, curr_bh, kaddr);
list = &cp->cp_snapshot_list;
prev = le64_to_cpu(list->ssl_prev);
}
kunmap_atomic(kaddr);
if (prev != 0) {
ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
&prev_bh);
if (ret < 0)
goto out_curr;
} else {
prev_bh = header_bh;
get_bh(prev_bh);
}
kaddr = kmap_atomic(curr_bh->b_page);
list = nilfs_cpfile_block_get_snapshot_list(
cpfile, curr, curr_bh, kaddr);
list->ssl_prev = cpu_to_le64(cno);
kunmap_atomic(kaddr);
kaddr = kmap_atomic(cp_bh->b_page);
cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
cp->cp_snapshot_list.ssl_next = cpu_to_le64(curr);
cp->cp_snapshot_list.ssl_prev = cpu_to_le64(prev);
nilfs_checkpoint_set_snapshot(cp);
kunmap_atomic(kaddr);
kaddr = kmap_atomic(prev_bh->b_page);
list = nilfs_cpfile_block_get_snapshot_list(
cpfile, prev, prev_bh, kaddr);
list->ssl_next = cpu_to_le64(cno);
kunmap_atomic(kaddr);
kaddr = kmap_atomic(header_bh->b_page);
header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
le64_add_cpu(&header->ch_nsnapshots, 1);
kunmap_atomic(kaddr);
mark_buffer_dirty(prev_bh);
mark_buffer_dirty(curr_bh);
mark_buffer_dirty(cp_bh);
mark_buffer_dirty(header_bh);
nilfs_mdt_mark_dirty(cpfile);
brelse(prev_bh);
out_curr:
brelse(curr_bh);
out_header:
brelse(header_bh);
out_cp:
brelse(cp_bh);
out_sem:
up_write(&NILFS_MDT(cpfile)->mi_sem);
return ret;
}
static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
void *buf, unsigned int cisz,
size_t nci)
{
struct buffer_head *bh;
struct nilfs_cpfile_header *header;
struct nilfs_checkpoint *cp;
struct nilfs_cpinfo *ci = buf;
__u64 curr = *cnop, next;
unsigned long curr_blkoff, next_blkoff;
void *kaddr;
int n = 0, ret;
down_read(&NILFS_MDT(cpfile)->mi_sem);
if (curr == 0) {
ret = nilfs_cpfile_get_header_block(cpfile, &bh);
if (ret < 0)
goto out;
kaddr = kmap_atomic(bh->b_page);
header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
curr = le64_to_cpu(header->ch_snapshot_list.ssl_next);
kunmap_atomic(kaddr);
brelse(bh);
if (curr == 0) {
ret = 0;
goto out;
}
} else if (unlikely(curr == ~(__u64)0)) {
ret = 0;
goto out;
}
curr_blkoff = nilfs_cpfile_get_blkoff(cpfile, curr);
ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, 0, &bh);
if (unlikely(ret < 0)) {
if (ret == -ENOENT)
ret = 0; /* No snapshots (started from a hole block) */
goto out;
}
kaddr = kmap_atomic(bh->b_page);
while (n < nci) {
cp = nilfs_cpfile_block_get_checkpoint(cpfile, curr, bh, kaddr);
curr = ~(__u64)0; /* Terminator */
if (unlikely(nilfs_checkpoint_invalid(cp) ||
!nilfs_checkpoint_snapshot(cp)))
break;
nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, ci);
ci = (void *)ci + cisz;
n++;
next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);
if (next == 0)
break; /* reach end of the snapshot list */
next_blkoff = nilfs_cpfile_get_blkoff(cpfile, next);
if (curr_blkoff != next_blkoff) {
kunmap_atomic(kaddr);
brelse(bh);
ret = nilfs_cpfile_get_checkpoint_block(cpfile, next,
0, &bh);
if (unlikely(ret < 0)) {
WARN_ON(ret == -ENOENT);
goto out;
}
kaddr = kmap_atomic(bh->b_page);
}
curr = next;
curr_blkoff = next_blkoff;
}
kunmap_atomic(kaddr);
brelse(bh);
*cnop = curr;
ret = n;
out:
up_read(&NILFS_MDT(cpfile)->mi_sem);
return ret;
}
