/**
* 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;
}
static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop,
void *buf, unsigned 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; cno < cur_cno && n < nci; cno += ncps) {
ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, cur_cno);
ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh);
if (ret < 0) {
if (ret != -ENOENT)
goto out;
continue; /* skip hole */
}
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;
}
static int nilfs_cpfile_clear_snapshot(struct inode *cpfile, __u64 cno)
{
struct buffer_head *header_bh, *next_bh, *prev_bh, *cp_bh;
struct nilfs_cpfile_header *header;
struct nilfs_checkpoint *cp;
struct nilfs_snapshot_list *list;
__u64 next, prev;
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;
}
list = &cp->cp_snapshot_list;
next = le64_to_cpu(list->ssl_next);
prev = le64_to_cpu(list->ssl_prev);
kunmap_atomic(kaddr);
ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
if (ret < 0)
goto out_cp;
if (next != 0) {
ret = nilfs_cpfile_get_checkpoint_block(cpfile, next, 0,
&next_bh);
if (ret < 0)
goto out_header;
} else {
next_bh = header_bh;
get_bh(next_bh);
}
if (prev != 0) {
ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
&prev_bh);
if (ret < 0)
goto out_next;
} else {
prev_bh = header_bh;
get_bh(prev_bh);
}
kaddr = kmap_atomic(next_bh->b_page);
list = nilfs_cpfile_block_get_snapshot_list(
cpfile, next, next_bh, kaddr);
list->ssl_prev = cpu_to_le64(prev);
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(next);
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(0);
cp->cp_snapshot_list.ssl_prev = cpu_to_le64(0);
nilfs_checkpoint_clear_snapshot(cp);
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(next_bh);
mark_buffer_dirty(prev_bh);
mark_buffer_dirty(cp_bh);
mark_buffer_dirty(header_bh);
nilfs_mdt_mark_dirty(cpfile);
brelse(prev_bh);
out_next:
brelse(next_bh);
out_header:
brelse(header_bh);
out_cp:
brelse(cp_bh);
out_sem:
up_write(&NILFS_MDT(cpfile)->mi_sem);
return ret;
}
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;
}
/**
* nilfs_cpfile_delete_checkpoints - delete checkpoints
* @cpfile: inode of checkpoint file
* @start: start checkpoint number
* @end: end checkpoint numer
*
* Description: nilfs_cpfile_delete_checkpoints() deletes the checkpoints in
* the period from @start to @end, excluding @end itself. The checkpoints
* which have been already deleted are ignored.
*
* Return Value: On success, 0 is returned. On error, one of the following
* negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*
* %-EINVAL - invalid checkpoints.
*/
int nilfs_cpfile_delete_checkpoints(struct inode *cpfile,
__u64 start,
__u64 end)
{
struct buffer_head *header_bh, *cp_bh;
struct nilfs_cpfile_header *header;
struct nilfs_checkpoint *cp;
size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
__u64 cno;
void *kaddr;
unsigned long tnicps;
int ret, ncps, nicps, nss, count, i;
if (unlikely(start == 0 || start > end)) {
printk(KERN_ERR "%s: invalid range of checkpoint numbers: "
"[%llu, %llu)\n", __func__,
(unsigned long long)start, (unsigned long long)end);
return -EINVAL;
}
down_write(&NILFS_MDT(cpfile)->mi_sem);
ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
if (ret < 0)
goto out_sem;
tnicps = 0;
nss = 0;
for (cno = start; cno < end; cno += ncps) {
ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, end);
ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
if (ret < 0) {
if (ret != -ENOENT)
break;
/* skip hole */
ret = 0;
continue;
}
kaddr = kmap_atomic(cp_bh->b_page);
cp = nilfs_cpfile_block_get_checkpoint(
cpfile, cno, cp_bh, kaddr);
nicps = 0;
for (i = 0; i < ncps; i++, cp = (void *)cp + cpsz) {
if (nilfs_checkpoint_snapshot(cp)) {
nss++;
} else if (!nilfs_checkpoint_invalid(cp)) {
nilfs_checkpoint_set_invalid(cp);
nicps++;
}
}
if (nicps > 0) {
tnicps += nicps;
mark_buffer_dirty(cp_bh);
nilfs_mdt_mark_dirty(cpfile);
if (!nilfs_cpfile_is_in_first(cpfile, cno)) {
count =
nilfs_cpfile_block_sub_valid_checkpoints(
cpfile, cp_bh, kaddr, nicps);
if (count == 0) {
/* make hole */
kunmap_atomic(kaddr);
brelse(cp_bh);
ret =
nilfs_cpfile_delete_checkpoint_block(
cpfile, cno);
if (ret == 0)
continue;
printk(KERN_ERR
"%s: cannot delete block\n",
__func__);
break;
}
}
}
kunmap_atomic(kaddr);
brelse(cp_bh);
}
if (tnicps > 0) {
kaddr = kmap_atomic(header_bh->b_page);
header = nilfs_cpfile_block_get_header(cpfile, header_bh,
kaddr);
le64_add_cpu(&header->ch_ncheckpoints, -(u64)tnicps);
mark_buffer_dirty(header_bh);
nilfs_mdt_mark_dirty(cpfile);
kunmap_atomic(kaddr);
}
brelse(header_bh);
if (nss > 0)
ret = -EBUSY;
out_sem:
up_write(&NILFS_MDT(cpfile)->mi_sem);
return ret;
}