/**
* nilfs_cpfile_get_checkpoint - get a checkpoint
* @cpfile: inode of checkpoint file
* @cno: checkpoint number
* @create: create flag
* @cpp: pointer to a checkpoint
* @bhp: pointer to a buffer head
*
* Description: nilfs_cpfile_get_checkpoint() acquires the checkpoint
* specified by @cno. A new checkpoint will be created if @cno is the current
* checkpoint number and @create is nonzero.
*
* Return Value: On success, 0 is returned, and the checkpoint and the
* buffer head of the buffer on which the checkpoint is located are stored in
* the place pointed by @cpp and @bhp, respectively. On error, one of the
* following negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*
* %-ENOENT - No such checkpoint.
*
* %-EINVAL - invalid checkpoint.
*/
int nilfs_cpfile_get_checkpoint(struct inode *cpfile,
__u64 cno,
int create,
struct nilfs_checkpoint **cpp,
struct buffer_head **bhp)
{
struct buffer_head *header_bh, *cp_bh;
struct nilfs_cpfile_header *header;
struct nilfs_checkpoint *cp;
void *kaddr;
int ret;
if (unlikely(cno < 1 || cno > nilfs_mdt_cno(cpfile) ||
(cno < nilfs_mdt_cno(cpfile) && create)))
return -EINVAL;
down_write(&NILFS_MDT(cpfile)->mi_sem);
ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
if (ret < 0)
goto out_sem;
ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, create, &cp_bh);
if (ret < 0)
goto out_header;
kaddr = kmap(cp_bh->b_page);
cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
if (nilfs_checkpoint_invalid(cp)) {
if (!create) {
kunmap(cp_bh->b_page);
brelse(cp_bh);
ret = -ENOENT;
goto out_header;
}
/* a newly-created checkpoint */
nilfs_checkpoint_clear_invalid(cp);
if (!nilfs_cpfile_is_in_first(cpfile, cno))
nilfs_cpfile_block_add_valid_checkpoints(cpfile, cp_bh,
kaddr, 1);
mark_buffer_dirty(cp_bh);
kaddr = kmap_atomic(header_bh->b_page);
header = nilfs_cpfile_block_get_header(cpfile, header_bh,
kaddr);
le64_add_cpu(&header->ch_ncheckpoints, 1);
kunmap_atomic(kaddr);
mark_buffer_dirty(header_bh);
nilfs_mdt_mark_dirty(cpfile);
}
if (cpp != NULL)
*cpp = cp;
*bhp = cp_bh;
out_header:
brelse(header_bh);
out_sem:
up_write(&NILFS_MDT(cpfile)->mi_sem);
return ret;
}
/**
* nilfs_cpfile_is_snapshot -
* @cpfile: inode of checkpoint file
* @cno: checkpoint number
*
* Description:
*
* Return Value: On success, 1 is returned if the checkpoint specified by
* @cno is a snapshot, or 0 if not. On error, one of the following negative
* error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*
* %-ENOENT - No such checkpoint.
*/
int nilfs_cpfile_is_snapshot(struct inode *cpfile, __u64 cno)
{
struct buffer_head *bh;
struct nilfs_checkpoint *cp;
void *kaddr;
int ret;
/*
* CP number is invalid if it's zero or larger than the
* largest existing one.
*/
if (cno == 0 || cno >= nilfs_mdt_cno(cpfile))
return -ENOENT;
down_read(&NILFS_MDT(cpfile)->mi_sem);
ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh);
if (ret < 0)
goto out;
kaddr = kmap_atomic(bh->b_page);
cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
if (nilfs_checkpoint_invalid(cp))
ret = -ENOENT;
else
ret = nilfs_checkpoint_snapshot(cp);
kunmap_atomic(kaddr);
brelse(bh);
out:
up_read(&NILFS_MDT(cpfile)->mi_sem);
return ret;
}
void nilfs_dat_commit_end(struct inode *dat, struct nilfs_palloc_req *req,
int dead)
{
struct nilfs_dat_entry *entry;
__u64 start, end;
sector_t blocknr;
void *kaddr;
kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
req->pr_entry_bh, kaddr);
end = start = le64_to_cpu(entry->de_start);
if (!dead) {
end = nilfs_mdt_cno(dat);
WARN_ON(start > end);
}
entry->de_end = cpu_to_le64(end);
blocknr = le64_to_cpu(entry->de_blocknr);
kunmap_atomic(kaddr, KM_USER0);
if (blocknr == 0)
nilfs_dat_commit_free(dat, req);
else
nilfs_dat_commit_entry(dat, req);
}
static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop,
void *buf, unsigned int cisz,
size_t nci)
{
struct nilfs_checkpoint *cp;
struct nilfs_cpinfo *ci = buf;
struct buffer_head *bh;
size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
__u64 cur_cno = nilfs_mdt_cno(cpfile), cno = *cnop;
void *kaddr;
int n, ret;
int ncps, i;
if (cno == 0)
return -ENOENT; /* checkpoint number 0 is invalid */
down_read(&NILFS_MDT(cpfile)->mi_sem);
for (n = 0; n < nci; cno += ncps) {
ret = nilfs_cpfile_find_checkpoint_block(
cpfile, cno, cur_cno - 1, &cno, &bh);
if (ret < 0) {
if (likely(ret == -ENOENT))
break;
goto out;
}
ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, cur_cno);
kaddr = kmap_atomic(bh->b_page);
cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
for (i = 0; i < ncps && n < nci; i++, cp = (void *)cp + cpsz) {
if (!nilfs_checkpoint_invalid(cp)) {
nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp,
ci);
ci = (void *)ci + cisz;
n++;
}
}
kunmap_atomic(kaddr);
brelse(bh);
}
ret = n;
if (n > 0) {
ci = (void *)ci - cisz;
*cnop = ci->ci_cno + 1;
}
out:
up_read(&NILFS_MDT(cpfile)->mi_sem);
return ret;
}
void nilfs_dat_commit_start(struct inode *dat, struct nilfs_palloc_req *req,
sector_t blocknr)
{
struct nilfs_dat_entry *entry;
void *kaddr;
kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
req->pr_entry_bh, kaddr);
entry->de_start = cpu_to_le64(nilfs_mdt_cno(dat));
entry->de_blocknr = cpu_to_le64(blocknr);
kunmap_atomic(kaddr, KM_USER0);
nilfs_dat_commit_entry(dat, req);
}
void nilfs_dat_abort_end(struct inode *dat, struct nilfs_palloc_req *req)
{
struct nilfs_dat_entry *entry;
__u64 start;
sector_t blocknr;
void *kaddr;
kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
req->pr_entry_bh, kaddr);
start = le64_to_cpu(entry->de_start);
blocknr = le64_to_cpu(entry->de_blocknr);
kunmap_atomic(kaddr, KM_USER0);
if (start == nilfs_mdt_cno(dat) && blocknr == 0)
nilfs_palloc_abort_free_entry(dat, req);
nilfs_dat_abort_entry(dat, req);
}
/**
* nilfs_cpfile_get_stat - get checkpoint statistics
* @cpfile: inode of checkpoint file
* @stat: pointer to a structure of checkpoint statistics
*
* Description: nilfs_cpfile_get_stat() returns information about checkpoints.
*
* Return Value: On success, 0 is returned, and checkpoints information is
* stored in the place pointed by @stat. On error, one of the following
* negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*/
int nilfs_cpfile_get_stat(struct inode *cpfile, struct nilfs_cpstat *cpstat)
{
struct buffer_head *bh;
struct nilfs_cpfile_header *header;
void *kaddr;
int ret;
down_read(&NILFS_MDT(cpfile)->mi_sem);
ret = nilfs_cpfile_get_header_block(cpfile, &bh);
if (ret < 0)
goto out_sem;
kaddr = kmap_atomic(bh->b_page);
header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
cpstat->cs_cno = nilfs_mdt_cno(cpfile);
cpstat->cs_ncps = le64_to_cpu(header->ch_ncheckpoints);
cpstat->cs_nsss = le64_to_cpu(header->ch_nsnapshots);
kunmap_atomic(kaddr);
brelse(bh);
out_sem:
up_read(&NILFS_MDT(cpfile)->mi_sem);
return ret;
}