void nilfs_sufile_do_set_error(struct inode *sufile, __u64 segnum,
struct buffer_head *header_bh,
struct buffer_head *su_bh)
{
struct nilfs_segment_usage *su;
void *kaddr;
int suclean;
kaddr = kmap_atomic(su_bh->b_page);
su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
if (nilfs_segment_usage_error(su)) {
kunmap_atomic(kaddr);
return;
}
suclean = nilfs_segment_usage_clean(su);
nilfs_segment_usage_set_error(su);
kunmap_atomic(kaddr);
if (suclean) {
nilfs_sufile_mod_counter(header_bh, -1, 0);
NILFS_SUI(sufile)->ncleansegs--;
}
mark_buffer_dirty(su_bh);
nilfs_mdt_mark_dirty(sufile);
}
void nilfs_sufile_do_free(struct inode *sufile, __u64 segnum,
struct buffer_head *header_bh,
struct buffer_head *su_bh)
{
struct nilfs_segment_usage *su;
void *kaddr;
int sudirty;
kaddr = kmap_atomic(su_bh->b_page);
su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
if (nilfs_segment_usage_clean(su)) {
printk(KERN_WARNING "%s: segment %llu is already clean\n",
__func__, (unsigned long long)segnum);
kunmap_atomic(kaddr);
return;
}
WARN_ON(nilfs_segment_usage_error(su));
WARN_ON(!nilfs_segment_usage_dirty(su));
sudirty = nilfs_segment_usage_dirty(su);
nilfs_segment_usage_set_clean(su);
kunmap_atomic(kaddr);
mark_buffer_dirty(su_bh);
nilfs_sufile_mod_counter(header_bh, 1, sudirty ? (u64)-1 : 0);
NILFS_SUI(sufile)->ncleansegs++;
nilfs_mdt_mark_dirty(sufile);
}
int nilfs_sufile_set_segment_usage(struct inode *sufile, __u64 segnum,
unsigned long nblocks, time_t modtime)
{
struct buffer_head *bh;
struct nilfs_segment_usage *su;
void *kaddr;
int ret;
down_write(&NILFS_MDT(sufile)->mi_sem);
ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh);
if (ret < 0)
goto out_sem;
kaddr = kmap_atomic(bh->b_page);
su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr);
WARN_ON(nilfs_segment_usage_error(su));
if (modtime)
su->su_lastmod = cpu_to_le64(modtime);
su->su_nblocks = cpu_to_le32(nblocks);
kunmap_atomic(kaddr);
mark_buffer_dirty(bh);
nilfs_mdt_mark_dirty(sufile);
brelse(bh);
out_sem:
up_write(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
/**
* nilfs_sufile_get_segment_usage - get a segment usage
* @sufile: inode of segment usage file
* @segnum: segment number
* @sup: pointer to segment usage
* @bhp: pointer to buffer head
*
* Description: nilfs_sufile_get_segment_usage() acquires the segment usage
* specified by @segnum.
*
* Return Value: On success, 0 is returned, and the segment usage and the
* buffer head of the buffer on which the segment usage is located are stored
* in the place pointed by @sup and @bhp, respectively. On error, one of the
* following negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*
* %-EINVAL - Invalid segment usage number.
*/
int nilfs_sufile_get_segment_usage(struct inode *sufile, __u64 segnum,
struct nilfs_segment_usage **sup,
struct buffer_head **bhp)
{
struct buffer_head *bh;
struct nilfs_segment_usage *su;
void *kaddr;
int ret;
/* segnum is 0 origin */
if (segnum >= nilfs_sufile_get_nsegments(sufile))
return -EINVAL;
down_write(&NILFS_MDT(sufile)->mi_sem);
ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1, &bh);
if (ret < 0)
goto out_sem;
kaddr = kmap(bh->b_page);
su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr);
if (nilfs_segment_usage_error(su)) {
kunmap(bh->b_page);
brelse(bh);
ret = -EINVAL;
goto out_sem;
}
if (sup != NULL)
*sup = su;
*bhp = bh;
out_sem:
up_write(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
void nilfs_sufile_do_scrap(struct inode *sufile, __u64 segnum,
struct buffer_head *header_bh,
struct buffer_head *su_bh)
{
struct nilfs_segment_usage *su;
void *kaddr;
int clean, dirty;
kaddr = kmap_atomic(su_bh->b_page);
su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
if (su->su_flags == cpu_to_le32(1UL << NILFS_SEGMENT_USAGE_DIRTY) &&
su->su_nblocks == cpu_to_le32(0)) {
kunmap_atomic(kaddr);
return;
}
clean = nilfs_segment_usage_clean(su);
dirty = nilfs_segment_usage_dirty(su);
su->su_lastmod = cpu_to_le64(0);
su->su_nblocks = cpu_to_le32(0);
su->su_flags = cpu_to_le32(1UL << NILFS_SEGMENT_USAGE_DIRTY);
kunmap_atomic(kaddr);
nilfs_sufile_mod_counter(header_bh, clean ? (u64)-1 : 0, dirty ? 0 : 1);
NILFS_SUI(sufile)->ncleansegs -= clean;
mark_buffer_dirty(su_bh);
nilfs_mdt_mark_dirty(sufile);
}
ssize_t nilfs_sufile_get_suinfo(struct inode *sufile, __u64 segnum, void *buf,
unsigned sisz, size_t nsi)
{
struct buffer_head *su_bh;
struct nilfs_segment_usage *su;
struct nilfs_suinfo *si = buf;
size_t susz = NILFS_MDT(sufile)->mi_entry_size;
struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
void *kaddr;
unsigned long nsegs, segusages_per_block;
ssize_t n;
int ret, i, j;
down_read(&NILFS_MDT(sufile)->mi_sem);
segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
nsegs = min_t(unsigned long,
nilfs_sufile_get_nsegments(sufile) - segnum,
nsi);
for (i = 0; i < nsegs; i += n, segnum += n) {
n = min_t(unsigned long,
segusages_per_block -
nilfs_sufile_get_offset(sufile, segnum),
nsegs - i);
ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
&su_bh);
if (ret < 0) {
if (ret != -ENOENT)
goto out;
memset(si, 0, sisz * n);
si = (void *)si + sisz * n;
continue;
}
kaddr = kmap_atomic(su_bh->b_page);
su = nilfs_sufile_block_get_segment_usage(
sufile, segnum, su_bh, kaddr);
for (j = 0; j < n;
j++, su = (void *)su + susz, si = (void *)si + sisz) {
si->sui_lastmod = le64_to_cpu(su->su_lastmod);
si->sui_nblocks = le32_to_cpu(su->su_nblocks);
si->sui_flags = le32_to_cpu(su->su_flags) &
~(1UL << NILFS_SEGMENT_USAGE_ACTIVE);
if (nilfs_segment_is_active(nilfs, segnum + j))
si->sui_flags |=
(1UL << NILFS_SEGMENT_USAGE_ACTIVE);
}
kunmap_atomic(kaddr);
brelse(su_bh);
}
ret = nsegs;
out:
up_read(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
void nilfs_sufile_do_cancel_free(struct inode *sufile, __u64 segnum,
struct buffer_head *header_bh,
struct buffer_head *su_bh)
{
struct nilfs_segment_usage *su;
void *kaddr;
kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
if (unlikely(!nilfs_segment_usage_clean(su))) {
printk(KERN_WARNING "%s: segment %llu must be clean\n",
__func__, (unsigned long long)segnum);
kunmap_atomic(kaddr, KM_USER0);
return;
}
nilfs_segment_usage_set_dirty(su);
kunmap_atomic(kaddr, KM_USER0);
nilfs_sufile_mod_counter(header_bh, -1, 1);
nilfs_mdt_mark_buffer_dirty(su_bh);
nilfs_mdt_mark_dirty(sufile);
}
static int nilfs_sufile_truncate_range(struct inode *sufile,
__u64 start, __u64 end)
{
struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
struct buffer_head *header_bh;
struct buffer_head *su_bh;
struct nilfs_segment_usage *su, *su2;
size_t susz = NILFS_MDT(sufile)->mi_entry_size;
unsigned long segusages_per_block;
unsigned long nsegs, ncleaned;
__u64 segnum;
void *kaddr;
ssize_t n, nc;
int ret;
int j;
nsegs = nilfs_sufile_get_nsegments(sufile);
ret = -EINVAL;
if (start > end || start >= nsegs)
goto out;
ret = nilfs_sufile_get_header_block(sufile, &header_bh);
if (ret < 0)
goto out;
segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
ncleaned = 0;
for (segnum = start; segnum <= end; segnum += n) {
n = min_t(unsigned long,
segusages_per_block -
nilfs_sufile_get_offset(sufile, segnum),
end - segnum + 1);
ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
&su_bh);
if (ret < 0) {
if (ret != -ENOENT)
goto out_header;
continue;
}
kaddr = kmap_atomic(su_bh->b_page);
su = nilfs_sufile_block_get_segment_usage(
sufile, segnum, su_bh, kaddr);
su2 = su;
for (j = 0; j < n; j++, su = (void *)su + susz) {
if ((le32_to_cpu(su->su_flags) &
~(1UL << NILFS_SEGMENT_USAGE_ERROR)) ||
nilfs_segment_is_active(nilfs, segnum + j)) {
ret = -EBUSY;
kunmap_atomic(kaddr);
brelse(su_bh);
goto out_header;
}
}
nc = 0;
for (su = su2, j = 0; j < n; j++, su = (void *)su + susz) {
if (nilfs_segment_usage_error(su)) {
nilfs_segment_usage_set_clean(su);
nc++;
}
}
kunmap_atomic(kaddr);
if (nc > 0) {
mark_buffer_dirty(su_bh);
ncleaned += nc;
}
brelse(su_bh);
if (n == segusages_per_block) {
nilfs_sufile_delete_segment_usage_block(sufile, segnum);
}
}
ret = 0;
out_header:
if (ncleaned > 0) {
NILFS_SUI(sufile)->ncleansegs += ncleaned;
nilfs_sufile_mod_counter(header_bh, ncleaned, 0);
nilfs_mdt_mark_dirty(sufile);
}
brelse(header_bh);
out:
return ret;
}
int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
{
struct buffer_head *header_bh, *su_bh;
struct nilfs_sufile_header *header;
struct nilfs_segment_usage *su;
struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
size_t susz = NILFS_MDT(sufile)->mi_entry_size;
__u64 segnum, maxsegnum, last_alloc;
void *kaddr;
unsigned long nsegments, ncleansegs, nsus, cnt;
int ret, j;
down_write(&NILFS_MDT(sufile)->mi_sem);
ret = nilfs_sufile_get_header_block(sufile, &header_bh);
if (ret < 0)
goto out_sem;
kaddr = kmap_atomic(header_bh->b_page);
header = kaddr + bh_offset(header_bh);
ncleansegs = le64_to_cpu(header->sh_ncleansegs);
last_alloc = le64_to_cpu(header->sh_last_alloc);
kunmap_atomic(kaddr);
nsegments = nilfs_sufile_get_nsegments(sufile);
maxsegnum = sui->allocmax;
segnum = last_alloc + 1;
if (segnum < sui->allocmin || segnum > sui->allocmax)
segnum = sui->allocmin;
for (cnt = 0; cnt < nsegments; cnt += nsus) {
if (segnum > maxsegnum) {
if (cnt < sui->allocmax - sui->allocmin + 1) {
segnum = sui->allocmin;
maxsegnum = last_alloc;
} else if (segnum > sui->allocmin &&
sui->allocmax + 1 < nsegments) {
segnum = sui->allocmax + 1;
maxsegnum = nsegments - 1;
} else if (sui->allocmin > 0) {
segnum = 0;
maxsegnum = sui->allocmin - 1;
} else {
break;
}
}
ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1,
&su_bh);
if (ret < 0)
goto out_header;
kaddr = kmap_atomic(su_bh->b_page);
su = nilfs_sufile_block_get_segment_usage(
sufile, segnum, su_bh, kaddr);
nsus = nilfs_sufile_segment_usages_in_block(
sufile, segnum, maxsegnum);
for (j = 0; j < nsus; j++, su = (void *)su + susz, segnum++) {
if (!nilfs_segment_usage_clean(su))
continue;
nilfs_segment_usage_set_dirty(su);
kunmap_atomic(kaddr);
kaddr = kmap_atomic(header_bh->b_page);
header = kaddr + bh_offset(header_bh);
le64_add_cpu(&header->sh_ncleansegs, -1);
le64_add_cpu(&header->sh_ndirtysegs, 1);
header->sh_last_alloc = cpu_to_le64(segnum);
kunmap_atomic(kaddr);
sui->ncleansegs--;
mark_buffer_dirty(header_bh);
mark_buffer_dirty(su_bh);
nilfs_mdt_mark_dirty(sufile);
brelse(su_bh);
*segnump = segnum;
goto out_header;
}
kunmap_atomic(kaddr);
brelse(su_bh);
}
ret = -ENOSPC;
out_header:
brelse(header_bh);
out_sem:
up_write(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
/**
* nilfs_sufile_set_suinfo - sets segment usage info
* @sufile: inode of segment usage file
* @buf: array of suinfo_update
* @supsz: byte size of suinfo_update
* @nsup: size of suinfo_update array
*
* Description: Takes an array of nilfs_suinfo_update structs and updates
* segment usage accordingly. Only the fields indicated by the sup_flags
* are updated.
*
* 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 values in input (segment number, flags or nblocks)
*/
ssize_t nilfs_sufile_set_suinfo(struct inode *sufile, void *buf,
unsigned int supsz, size_t nsup)
{
struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
struct buffer_head *header_bh, *bh;
struct nilfs_suinfo_update *sup, *supend = buf + supsz * nsup;
struct nilfs_segment_usage *su;
void *kaddr;
unsigned long blkoff, prev_blkoff;
int cleansi, cleansu, dirtysi, dirtysu;
long ncleaned = 0, ndirtied = 0;
int ret = 0;
if (unlikely(nsup == 0))
return ret;
for (sup = buf; sup < supend; sup = (void *)sup + supsz) {
if (sup->sup_segnum >= nilfs->ns_nsegments
|| (sup->sup_flags &
(~0UL << __NR_NILFS_SUINFO_UPDATE_FIELDS))
|| (nilfs_suinfo_update_nblocks(sup) &&
sup->sup_sui.sui_nblocks >
nilfs->ns_blocks_per_segment))
return -EINVAL;
}
down_write(&NILFS_MDT(sufile)->mi_sem);
ret = nilfs_sufile_get_header_block(sufile, &header_bh);
if (ret < 0)
goto out_sem;
sup = buf;
blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
if (ret < 0)
goto out_header;
for (;;) {
kaddr = kmap_atomic(bh->b_page, KM_USER0);
su = nilfs_sufile_block_get_segment_usage(
sufile, sup->sup_segnum, bh, kaddr);
if (nilfs_suinfo_update_lastmod(sup))
su->su_lastmod = cpu_to_le64(sup->sup_sui.sui_lastmod);
if (nilfs_suinfo_update_nblocks(sup))
su->su_nblocks = cpu_to_le32(sup->sup_sui.sui_nblocks);
if (nilfs_suinfo_update_flags(sup)) {
/*
* Active flag is a virtual flag projected by running
* nilfs kernel code - drop it not to write it to
* disk.
*/
sup->sup_sui.sui_flags &=
~(1UL << NILFS_SEGMENT_USAGE_ACTIVE);
cleansi = nilfs_suinfo_clean(&sup->sup_sui);
cleansu = nilfs_segment_usage_clean(su);
dirtysi = nilfs_suinfo_dirty(&sup->sup_sui);
dirtysu = nilfs_segment_usage_dirty(su);
if (cleansi && !cleansu)
++ncleaned;
else if (!cleansi && cleansu)
--ncleaned;
if (dirtysi && !dirtysu)
++ndirtied;
else if (!dirtysi && dirtysu)
--ndirtied;
su->su_flags = cpu_to_le32(sup->sup_sui.sui_flags);
}
kunmap_atomic(kaddr, KM_USER0);
sup = (void *)sup + supsz;
if (sup >= supend)
break;
prev_blkoff = blkoff;
blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
if (blkoff == prev_blkoff)
continue;
/* get different block */
mark_buffer_dirty(bh);
put_bh(bh);
ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
if (unlikely(ret < 0))
goto out_mark;
}
mark_buffer_dirty(bh);
put_bh(bh);
out_mark:
if (ncleaned || ndirtied) {
nilfs_sufile_mod_counter(header_bh, (u64)ncleaned,
(u64)ndirtied);
NILFS_SUI(sufile)->ncleansegs += ncleaned;
}
nilfs_mdt_mark_dirty(sufile);
out_header:
put_bh(header_bh);
out_sem:
up_write(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
/**
* nilfs_sufile_trim_fs() - trim ioctl handle function
* @sufile: inode of segment usage file
* @range: fstrim_range structure
*
* start: First Byte to trim
* len: number of Bytes to trim from start
* minlen: minimum extent length in Bytes
*
* Decription: nilfs_sufile_trim_fs goes through all segments containing bytes
* from start to start+len. start is rounded up to the next block boundary
* and start+len is rounded down. For each clean segment blkdev_issue_discard
* function is invoked.
*
* Return Value: On success, 0 is returned or negative error code, otherwise.
*/
int nilfs_sufile_trim_fs(struct inode *sufile, struct fstrim_range *range)
{
struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
struct buffer_head *su_bh;
struct nilfs_segment_usage *su;
void *kaddr;
size_t n, i, susz = NILFS_MDT(sufile)->mi_entry_size;
sector_t seg_start, seg_end, start_block, end_block;
sector_t start = 0, nblocks = 0;
u64 segnum, segnum_end, minlen, len, max_blocks, ndiscarded = 0;
int ret = 0;
unsigned int sects_per_block;
sects_per_block = (1 << nilfs->ns_blocksize_bits) /
bdev_logical_block_size(nilfs->ns_bdev);
len = range->len >> nilfs->ns_blocksize_bits;
minlen = range->minlen >> nilfs->ns_blocksize_bits;
max_blocks = ((u64)nilfs->ns_nsegments * nilfs->ns_blocks_per_segment);
if (!len || range->start >= max_blocks << nilfs->ns_blocksize_bits)
return -EINVAL;
start_block = (range->start + nilfs->ns_blocksize - 1) >>
nilfs->ns_blocksize_bits;
/*
* range->len can be very large (actually, it is set to
* ULLONG_MAX by default) - truncate upper end of the range
* carefully so as not to overflow.
*/
if (max_blocks - start_block < len)
end_block = max_blocks - 1;
else
end_block = start_block + len - 1;
segnum = nilfs_get_segnum_of_block(nilfs, start_block);
segnum_end = nilfs_get_segnum_of_block(nilfs, end_block);
down_read(&NILFS_MDT(sufile)->mi_sem);
while (segnum <= segnum_end) {
n = nilfs_sufile_segment_usages_in_block(sufile, segnum,
segnum_end);
ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
&su_bh);
if (ret < 0) {
if (ret != -ENOENT)
goto out_sem;
/* hole */
segnum += n;
continue;
}
kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
su = nilfs_sufile_block_get_segment_usage(sufile, segnum,
su_bh, kaddr);
for (i = 0; i < n; ++i, ++segnum, su = (void *)su + susz) {
if (!nilfs_segment_usage_clean(su))
continue;
nilfs_get_segment_range(nilfs, segnum, &seg_start,
&seg_end);
if (!nblocks) {
/* start new extent */
start = seg_start;
nblocks = seg_end - seg_start + 1;
continue;
}
if (start + nblocks == seg_start) {
/* add to previous extent */
nblocks += seg_end - seg_start + 1;
continue;
}
/* discard previous extent */
if (start < start_block) {
nblocks -= start_block - start;
start = start_block;
}
if (nblocks >= minlen) {
kunmap_atomic(kaddr, KM_USER0);
ret = compat_blkdev_issue_discard(
nilfs->ns_bdev, start * sects_per_block,
nblocks * sects_per_block, GFP_NOFS, 0);
if (ret < 0) {
put_bh(su_bh);
goto out_sem;
}
ndiscarded += nblocks;
kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
su = nilfs_sufile_block_get_segment_usage(
sufile, segnum, su_bh, kaddr);
}
/* start new extent */
start = seg_start;
nblocks = seg_end - seg_start + 1;
}
kunmap_atomic(kaddr, KM_USER0);
put_bh(su_bh);
}
if (nblocks) {
/* discard last extent */
if (start < start_block) {
nblocks -= start_block - start;
start = start_block;
}
if (start + nblocks > end_block + 1)
nblocks = end_block - start + 1;
if (nblocks >= minlen) {
ret = compat_blkdev_issue_discard(
nilfs->ns_bdev, start * sects_per_block,
nblocks * sects_per_block, GFP_NOFS, 0);
if (!ret)
ndiscarded += nblocks;
}
}
out_sem:
up_read(&NILFS_MDT(sufile)->mi_sem);
range->len = ndiscarded << nilfs->ns_blocksize_bits;
return ret;
}
/**
* nilfs_sufile_alloc - allocate a segment
* @sufile: inode of segment usage file
* @segnump: pointer to segment number
*
* Description: nilfs_sufile_alloc() allocates a clean segment.
*
* Return Value: On success, 0 is returned and the segment number of the
* allocated segment is stored in the place pointed by @segnump. On error, one
* of the following negative error codes is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*
* %-ENOSPC - No clean segment left.
*/
int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
{
struct buffer_head *header_bh, *su_bh;
struct nilfs_sufile_header *header;
struct nilfs_segment_usage *su;
size_t susz = NILFS_MDT(sufile)->mi_entry_size;
__u64 segnum, maxsegnum, last_alloc;
void *kaddr;
unsigned long nsegments, ncleansegs, nsus;
int ret, i, j;
down_write(&NILFS_MDT(sufile)->mi_sem);
ret = nilfs_sufile_get_header_block(sufile, &header_bh);
if (ret < 0)
goto out_sem;
kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr);
ncleansegs = le64_to_cpu(header->sh_ncleansegs);
last_alloc = le64_to_cpu(header->sh_last_alloc);
kunmap_atomic(kaddr, KM_USER0);
nsegments = nilfs_sufile_get_nsegments(sufile);
segnum = last_alloc + 1;
maxsegnum = nsegments - 1;
for (i = 0; i < nsegments; i += nsus) {
if (segnum >= nsegments) {
/* wrap around */
segnum = 0;
maxsegnum = last_alloc;
}
ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1,
&su_bh);
if (ret < 0)
goto out_header;
kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
su = nilfs_sufile_block_get_segment_usage(
sufile, segnum, su_bh, kaddr);
nsus = nilfs_sufile_segment_usages_in_block(
sufile, segnum, maxsegnum);
for (j = 0; j < nsus; j++, su = (void *)su + susz, segnum++) {
if (!nilfs_segment_usage_clean(su))
continue;
/* found a clean segment */
nilfs_segment_usage_set_dirty(su);
kunmap_atomic(kaddr, KM_USER0);
kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
header = nilfs_sufile_block_get_header(
sufile, header_bh, kaddr);
le64_add_cpu(&header->sh_ncleansegs, -1);
le64_add_cpu(&header->sh_ndirtysegs, 1);
header->sh_last_alloc = cpu_to_le64(segnum);
kunmap_atomic(kaddr, KM_USER0);
nilfs_mdt_mark_buffer_dirty(header_bh);
nilfs_mdt_mark_buffer_dirty(su_bh);
nilfs_mdt_mark_dirty(sufile);
brelse(su_bh);
*segnump = segnum;
goto out_header;
}
kunmap_atomic(kaddr, KM_USER0);
brelse(su_bh);
}
/* no segments left */
ret = -ENOSPC;
out_header:
brelse(header_bh);
out_sem:
up_write(&NILFS_MDT(sufile)->mi_sem);
return ret;
}
