Commit 8a9d2191 authored by Ryusuke Konishi's avatar Ryusuke Konishi Committed by Linus Torvalds
Browse files

nilfs2: operations for the_nilfs core object



This adds functions on the_nilfs object, which keeps shared resources and
states among a read/write mount and snapshots mounts going individually.

the_nilfs is allocated per block device; it is created when user first
mount a snapshot or a read/write mount on the device, then it is reused
for successive mounts.  It will be freed when all mount instances on the
device are detached.
Signed-off-by: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d2500652
/*
* the_nilfs.c - the_nilfs shared structure.
*
* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Written by Ryusuke Konishi <ryusuke@osrg.net>
*
*/
#include <linux/buffer_head.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include "nilfs.h"
#include "segment.h"
#include "alloc.h"
#include "cpfile.h"
#include "sufile.h"
#include "dat.h"
#include "seglist.h"
#include "segbuf.h"
void nilfs_set_last_segment(struct the_nilfs *nilfs,
sector_t start_blocknr, u64 seq, __u64 cno)
{
spin_lock(&nilfs->ns_last_segment_lock);
nilfs->ns_last_pseg = start_blocknr;
nilfs->ns_last_seq = seq;
nilfs->ns_last_cno = cno;
spin_unlock(&nilfs->ns_last_segment_lock);
}
/**
* alloc_nilfs - allocate the_nilfs structure
* @bdev: block device to which the_nilfs is related
*
* alloc_nilfs() allocates memory for the_nilfs and
* initializes its reference count and locks.
*
* Return Value: On success, pointer to the_nilfs is returned.
* On error, NULL is returned.
*/
struct the_nilfs *alloc_nilfs(struct block_device *bdev)
{
struct the_nilfs *nilfs;
nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL);
if (!nilfs)
return NULL;
nilfs->ns_bdev = bdev;
atomic_set(&nilfs->ns_count, 1);
atomic_set(&nilfs->ns_writer_refcount, -1);
atomic_set(&nilfs->ns_ndirtyblks, 0);
init_rwsem(&nilfs->ns_sem);
mutex_init(&nilfs->ns_writer_mutex);
INIT_LIST_HEAD(&nilfs->ns_supers);
spin_lock_init(&nilfs->ns_last_segment_lock);
nilfs->ns_gc_inodes_h = NULL;
INIT_LIST_HEAD(&nilfs->ns_used_segments);
init_rwsem(&nilfs->ns_segctor_sem);
init_waitqueue_head(&nilfs->ns_cleanerd_wq);
return nilfs;
}
/**
* put_nilfs - release a reference to the_nilfs
* @nilfs: the_nilfs structure to be released
*
* put_nilfs() decrements a reference counter of the_nilfs.
* If the reference count reaches zero, the_nilfs is freed.
*/
void put_nilfs(struct the_nilfs *nilfs)
{
if (!atomic_dec_and_test(&nilfs->ns_count))
return;
/*
* Increment of ns_count never occur below because the caller
* of get_nilfs() holds at least one reference to the_nilfs.
* Thus its exclusion control is not required here.
*/
might_sleep();
if (nilfs_loaded(nilfs)) {
nilfs_dispose_used_segments(nilfs);
nilfs_mdt_clear(nilfs->ns_sufile);
nilfs_mdt_destroy(nilfs->ns_sufile);
nilfs_mdt_clear(nilfs->ns_cpfile);
nilfs_mdt_destroy(nilfs->ns_cpfile);
nilfs_mdt_clear(nilfs->ns_dat);
nilfs_mdt_destroy(nilfs->ns_dat);
/* XXX: how and when to clear nilfs->ns_gc_dat? */
nilfs_mdt_destroy(nilfs->ns_gc_dat);
}
if (nilfs_init(nilfs)) {
nilfs_destroy_gccache(nilfs);
brelse(nilfs->ns_sbh);
}
kfree(nilfs);
}
static int nilfs_load_super_root(struct the_nilfs *nilfs,
struct nilfs_sb_info *sbi, sector_t sr_block)
{
struct buffer_head *bh_sr;
struct nilfs_super_root *raw_sr;
unsigned dat_entry_size, segment_usage_size, checkpoint_size;
unsigned inode_size;
int err;
err = nilfs_read_super_root_block(sbi->s_super, sr_block, &bh_sr, 1);
if (unlikely(err))
return err;
down_read(&nilfs->ns_sem);
dat_entry_size = le16_to_cpu(nilfs->ns_sbp->s_dat_entry_size);
checkpoint_size = le16_to_cpu(nilfs->ns_sbp->s_checkpoint_size);
segment_usage_size = le16_to_cpu(nilfs->ns_sbp->s_segment_usage_size);
up_read(&nilfs->ns_sem);
inode_size = nilfs->ns_inode_size;
err = -ENOMEM;
nilfs->ns_dat = nilfs_mdt_new(
nilfs, NULL, NILFS_DAT_INO, NILFS_DAT_GFP);
if (unlikely(!nilfs->ns_dat))
goto failed;
nilfs->ns_gc_dat = nilfs_mdt_new(
nilfs, NULL, NILFS_DAT_INO, NILFS_DAT_GFP);
if (unlikely(!nilfs->ns_gc_dat))
goto failed_dat;
nilfs->ns_cpfile = nilfs_mdt_new(
nilfs, NULL, NILFS_CPFILE_INO, NILFS_CPFILE_GFP);
if (unlikely(!nilfs->ns_cpfile))
goto failed_gc_dat;
nilfs->ns_sufile = nilfs_mdt_new(
nilfs, NULL, NILFS_SUFILE_INO, NILFS_SUFILE_GFP);
if (unlikely(!nilfs->ns_sufile))
goto failed_cpfile;
err = nilfs_palloc_init_blockgroup(nilfs->ns_dat, dat_entry_size);
if (unlikely(err))
goto failed_sufile;
err = nilfs_palloc_init_blockgroup(nilfs->ns_gc_dat, dat_entry_size);
if (unlikely(err))
goto failed_sufile;
nilfs_mdt_set_shadow(nilfs->ns_dat, nilfs->ns_gc_dat);
nilfs_mdt_set_entry_size(nilfs->ns_cpfile, checkpoint_size,
sizeof(struct nilfs_cpfile_header));
nilfs_mdt_set_entry_size(nilfs->ns_sufile, segment_usage_size,
sizeof(struct nilfs_sufile_header));
err = nilfs_mdt_read_inode_direct(
nilfs->ns_dat, bh_sr, NILFS_SR_DAT_OFFSET(inode_size));
if (unlikely(err))
goto failed_sufile;
err = nilfs_mdt_read_inode_direct(
nilfs->ns_cpfile, bh_sr, NILFS_SR_CPFILE_OFFSET(inode_size));
if (unlikely(err))
goto failed_sufile;
err = nilfs_mdt_read_inode_direct(
nilfs->ns_sufile, bh_sr, NILFS_SR_SUFILE_OFFSET(inode_size));
if (unlikely(err))
goto failed_sufile;
raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime);
failed:
brelse(bh_sr);
return err;
failed_sufile:
nilfs_mdt_destroy(nilfs->ns_sufile);
failed_cpfile:
nilfs_mdt_destroy(nilfs->ns_cpfile);
failed_gc_dat:
nilfs_mdt_destroy(nilfs->ns_gc_dat);
failed_dat:
nilfs_mdt_destroy(nilfs->ns_dat);
goto failed;
}
static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri)
{
memset(ri, 0, sizeof(*ri));
INIT_LIST_HEAD(&ri->ri_used_segments);
}
static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri)
{
nilfs_dispose_segment_list(&ri->ri_used_segments);
}
/**
* load_nilfs - load and recover the nilfs
* @nilfs: the_nilfs structure to be released
* @sbi: nilfs_sb_info used to recover past segment
*
* load_nilfs() searches and load the latest super root,
* attaches the last segment, and does recovery if needed.
* The caller must call this exclusively for simultaneous mounts.
*/
int load_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
{
struct nilfs_recovery_info ri;
unsigned int s_flags = sbi->s_super->s_flags;
int really_read_only = bdev_read_only(nilfs->ns_bdev);
unsigned valid_fs;
int err = 0;
nilfs_init_recovery_info(&ri);
down_write(&nilfs->ns_sem);
valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS);
up_write(&nilfs->ns_sem);
if (!valid_fs && (s_flags & MS_RDONLY)) {
printk(KERN_INFO "NILFS: INFO: recovery "
"required for readonly filesystem.\n");
if (really_read_only) {
printk(KERN_ERR "NILFS: write access "
"unavailable, cannot proceed.\n");
err = -EROFS;
goto failed;
}
printk(KERN_INFO "NILFS: write access will "
"be enabled during recovery.\n");
sbi->s_super->s_flags &= ~MS_RDONLY;
}
err = nilfs_search_super_root(nilfs, sbi, &ri);
if (unlikely(err)) {
printk(KERN_ERR "NILFS: error searching super root.\n");
goto failed;
}
err = nilfs_load_super_root(nilfs, sbi, ri.ri_super_root);
if (unlikely(err)) {
printk(KERN_ERR "NILFS: error loading super root.\n");
goto failed;
}
if (!valid_fs) {
err = nilfs_recover_logical_segments(nilfs, sbi, &ri);
if (unlikely(err)) {
nilfs_mdt_destroy(nilfs->ns_cpfile);
nilfs_mdt_destroy(nilfs->ns_sufile);
nilfs_mdt_destroy(nilfs->ns_dat);
goto failed;
}
if (ri.ri_need_recovery == NILFS_RECOVERY_SR_UPDATED) {
down_write(&nilfs->ns_sem);
nilfs_update_last_segment(sbi, 0);
up_write(&nilfs->ns_sem);
}
}
set_nilfs_loaded(nilfs);
failed:
nilfs_clear_recovery_info(&ri);
sbi->s_super->s_flags = s_flags;
return err;
}
static unsigned long long nilfs_max_size(unsigned int blkbits)
{
unsigned int max_bits;
unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */
max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */
if (max_bits < 64)
res = min_t(unsigned long long, res, (1ULL << max_bits) - 1);
return res;
}
static int
nilfs_store_disk_layout(struct the_nilfs *nilfs, struct super_block *sb,
struct nilfs_super_block *sbp)
{
if (le32_to_cpu(sbp->s_rev_level) != NILFS_CURRENT_REV) {
printk(KERN_ERR "NILFS: revision mismatch "
"(superblock rev.=%d.%d, current rev.=%d.%d). "
"Please check the version of mkfs.nilfs.\n",
le32_to_cpu(sbp->s_rev_level),
le16_to_cpu(sbp->s_minor_rev_level),
NILFS_CURRENT_REV, NILFS_MINOR_REV);
return -EINVAL;
}
nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size);
nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);
nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
printk(KERN_ERR "NILFS: too short segment. \n");
return -EINVAL;
}
nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
nilfs->ns_nsegments = le64_to_cpu(sbp->s_nsegments);
nilfs->ns_r_segments_percentage =
le32_to_cpu(sbp->s_r_segments_percentage);
nilfs->ns_nrsvsegs =
max_t(unsigned long, NILFS_MIN_NRSVSEGS,
DIV_ROUND_UP(nilfs->ns_nsegments *
nilfs->ns_r_segments_percentage, 100));
nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
return 0;
}
/**
* init_nilfs - initialize a NILFS instance.
* @nilfs: the_nilfs structure
* @sbi: nilfs_sb_info
* @sb: super block
* @data: mount options
*
* init_nilfs() performs common initialization per block device (e.g.
* reading the super block, getting disk layout information, initializing
* shared fields in the_nilfs). It takes on some portion of the jobs
* typically done by a fill_super() routine. This division arises from
* the nature that multiple NILFS instances may be simultaneously
* mounted on a device.
* For multiple mounts on the same device, only the first mount
* invokes these tasks.
*
* Return Value: On success, 0 is returned. On error, a negative error
* code is returned.
*/
int init_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi, char *data)
{
struct super_block *sb = sbi->s_super;
struct buffer_head *sbh;
struct nilfs_super_block *sbp;
struct backing_dev_info *bdi;
int blocksize;
int err = 0;
down_write(&nilfs->ns_sem);
if (nilfs_init(nilfs)) {
/* Load values from existing the_nilfs */
sbp = nilfs->ns_sbp;
err = nilfs_store_magic_and_option(sb, sbp, data);
if (err)
goto out;
blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
if (sb->s_blocksize != blocksize &&
!sb_set_blocksize(sb, blocksize)) {
printk(KERN_ERR "NILFS: blocksize %d unfit to device\n",
blocksize);
err = -EINVAL;
}
sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
goto out;
}
sbp = nilfs_load_super_block(sb, &sbh);
if (!sbp) {
err = -EINVAL;
goto out;
}
err = nilfs_store_magic_and_option(sb, sbp, data);
if (err)
goto failed_sbh;
blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
if (sb->s_blocksize != blocksize) {
sbp = nilfs_reload_super_block(sb, &sbh, blocksize);
if (!sbp) {
err = -EINVAL;
goto out;
/* not failed_sbh; sbh is released automatically
when reloading fails. */
}
}
nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
err = nilfs_store_disk_layout(nilfs, sb, sbp);
if (err)
goto failed_sbh;
sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);
nilfs->ns_sbh = sbh;
nilfs->ns_sbp = sbp;
bdi = nilfs->ns_bdev->bd_inode_backing_dev_info;
if (!bdi)
bdi = nilfs->ns_bdev->bd_inode->i_mapping->backing_dev_info;
nilfs->ns_bdi = bdi ? : &default_backing_dev_info;
/* Finding last segment */
nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg);
nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno);
nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq);
nilfs->ns_seg_seq = nilfs->ns_last_seq;
nilfs->ns_segnum =
nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg);
nilfs->ns_cno = nilfs->ns_last_cno + 1;
if (nilfs->ns_segnum >= nilfs->ns_nsegments) {
printk(KERN_ERR "NILFS invalid last segment number.\n");
err = -EINVAL;
goto failed_sbh;
}
/* Dummy values */
nilfs->ns_free_segments_count =
nilfs->ns_nsegments - (nilfs->ns_segnum + 1);
/* Initialize gcinode cache */
err = nilfs_init_gccache(nilfs);
if (err)
goto failed_sbh;
set_nilfs_init(nilfs);
err = 0;
out:
up_write(&nilfs->ns_sem);
return err;
failed_sbh:
brelse(sbh);
goto out;
}
int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
{
struct inode *dat = nilfs_dat_inode(nilfs);
unsigned long ncleansegs;
int err;
down_read(&NILFS_MDT(dat)->mi_sem); /* XXX */
err = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile, &ncleansegs);
up_read(&NILFS_MDT(dat)->mi_sem); /* XXX */
if (likely(!err))
*nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
return err;
}
void nilfs_dispose_used_segments(struct the_nilfs *nilfs)
{
struct nilfs_segment_entry *ent, *n;
/* nilfs->sem must be locked by the caller. */
if (!nilfs_loaded(nilfs))
return;
list_for_each_entry_safe(ent, n, &nilfs->ns_used_segments, list) {
list_del_init(&ent->list);
nilfs_segment_usage_clear_volatile_active(ent->raw_su);
nilfs_close_segment_entry(ent, nilfs->ns_sufile);
nilfs_free_segment_entry(ent);
}
}
int nilfs_near_disk_full(struct the_nilfs *nilfs)
{
struct inode *sufile = nilfs->ns_sufile;
unsigned long ncleansegs, nincsegs;
int ret;
ret = nilfs_sufile_get_ncleansegs(sufile, &ncleansegs);
if (likely(!ret)) {
nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
nilfs->ns_blocks_per_segment + 1;
if (ncleansegs <= nilfs->ns_nrsvsegs + nincsegs)
ret++;
}
return ret;
}
int nilfs_checkpoint_is_mounted(struct the_nilfs *nilfs, __u64 cno,
int snapshot_mount)
{
struct nilfs_sb_info *sbi;
int ret = 0;
down_read(&nilfs->ns_sem);
if (cno == 0 || cno > nilfs->ns_cno)
goto out_unlock;
list_for_each_entry(sbi, &nilfs->ns_supers, s_list) {
if (sbi->s_snapshot_cno == cno &&
(!snapshot_mount || nilfs_test_opt(sbi, SNAPSHOT))) {
/* exclude read-only mounts */
ret++;
break;
}
}
/* for protecting recent checkpoints */
if (cno >= nilfs_last_cno(nilfs))
ret++;
out_unlock:
up_read(&nilfs->ns_sem);
return ret;
}
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment