zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/fs/nilfs2/the_nilfs.c b/ap/os/linux/linux-3.4.x/fs/nilfs2/the_nilfs.c
new file mode 100644
index 0000000..41e6a04
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/nilfs2/the_nilfs.c
@@ -0,0 +1,791 @@
+/*
+ * 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 <linux/random.h>
+#include <linux/crc32.h>
+#include "nilfs.h"
+#include "segment.h"
+#include "alloc.h"
+#include "cpfile.h"
+#include "sufile.h"
+#include "dat.h"
+#include "segbuf.h"
+
+
+static int nilfs_valid_sb(struct nilfs_super_block *sbp);
+
+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;
+
+ if (!nilfs_sb_dirty(nilfs)) {
+ if (nilfs->ns_prev_seq == nilfs->ns_last_seq)
+ goto stay_cursor;
+
+ set_nilfs_sb_dirty(nilfs);
+ }
+ nilfs->ns_prev_seq = nilfs->ns_last_seq;
+
+ stay_cursor:
+ spin_unlock(&nilfs->ns_last_segment_lock);
+}
+
+/**
+ * alloc_nilfs - allocate a nilfs object
+ * @bdev: block device to which the_nilfs is related
+ *
+ * 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_ndirtyblks, 0);
+ init_rwsem(&nilfs->ns_sem);
+ mutex_init(&nilfs->ns_snapshot_mount_mutex);
+ INIT_LIST_HEAD(&nilfs->ns_dirty_files);
+ INIT_LIST_HEAD(&nilfs->ns_gc_inodes);
+ spin_lock_init(&nilfs->ns_inode_lock);
+ spin_lock_init(&nilfs->ns_next_gen_lock);
+ spin_lock_init(&nilfs->ns_last_segment_lock);
+ nilfs->ns_cptree = RB_ROOT;
+ spin_lock_init(&nilfs->ns_cptree_lock);
+ init_rwsem(&nilfs->ns_segctor_sem);
+
+ return nilfs;
+}
+
+/**
+ * destroy_nilfs - destroy nilfs object
+ * @nilfs: nilfs object to be released
+ */
+void destroy_nilfs(struct the_nilfs *nilfs)
+{
+ might_sleep();
+ if (nilfs_init(nilfs)) {
+ brelse(nilfs->ns_sbh[0]);
+ brelse(nilfs->ns_sbh[1]);
+ }
+ kfree(nilfs);
+}
+
+static int nilfs_load_super_root(struct the_nilfs *nilfs,
+ struct super_block *sb, sector_t sr_block)
+{
+ struct buffer_head *bh_sr;
+ struct nilfs_super_root *raw_sr;
+ struct nilfs_super_block **sbp = nilfs->ns_sbp;
+ struct nilfs_inode *rawi;
+ unsigned dat_entry_size, segment_usage_size, checkpoint_size;
+ unsigned inode_size;
+ int err;
+
+ err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1);
+ if (unlikely(err))
+ return err;
+
+ down_read(&nilfs->ns_sem);
+ dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size);
+ checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size);
+ segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size);
+ up_read(&nilfs->ns_sem);
+
+ inode_size = nilfs->ns_inode_size;
+
+ rawi = (void *)bh_sr->b_data + NILFS_SR_DAT_OFFSET(inode_size);
+ err = nilfs_dat_read(sb, dat_entry_size, rawi, &nilfs->ns_dat);
+ if (err)
+ goto failed;
+
+ rawi = (void *)bh_sr->b_data + NILFS_SR_CPFILE_OFFSET(inode_size);
+ err = nilfs_cpfile_read(sb, checkpoint_size, rawi, &nilfs->ns_cpfile);
+ if (err)
+ goto failed_dat;
+
+ rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size);
+ err = nilfs_sufile_read(sb, segment_usage_size, rawi,
+ &nilfs->ns_sufile);
+ if (err)
+ goto failed_cpfile;
+
+ 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_cpfile:
+ iput(nilfs->ns_cpfile);
+
+ failed_dat:
+ iput(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);
+}
+
+/**
+ * nilfs_store_log_cursor - load log cursor from a super block
+ * @nilfs: nilfs object
+ * @sbp: buffer storing super block to be read
+ *
+ * nilfs_store_log_cursor() reads the last position of the log
+ * containing a super root from a given super block, and initializes
+ * relevant information on the nilfs object preparatory for log
+ * scanning and recovery.
+ */
+static int nilfs_store_log_cursor(struct the_nilfs *nilfs,
+ struct nilfs_super_block *sbp)
+{
+ int ret = 0;
+
+ 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_prev_seq = nilfs->ns_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");
+ ret = -EINVAL;
+ }
+ return ret;
+}
+
+/**
+ * load_nilfs - load and recover the nilfs
+ * @nilfs: the_nilfs structure to be released
+ * @sb: super block isntance 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 super_block *sb)
+{
+ struct nilfs_recovery_info ri;
+ unsigned int s_flags = sb->s_flags;
+ int really_read_only = bdev_read_only(nilfs->ns_bdev);
+ int valid_fs = nilfs_valid_fs(nilfs);
+ int err;
+
+ if (!valid_fs) {
+ printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n");
+ if (s_flags & MS_RDONLY) {
+ printk(KERN_INFO "NILFS: INFO: recovery "
+ "required for readonly filesystem.\n");
+ printk(KERN_INFO "NILFS: write access will "
+ "be enabled during recovery.\n");
+ }
+ }
+
+ nilfs_init_recovery_info(&ri);
+
+ err = nilfs_search_super_root(nilfs, &ri);
+ if (unlikely(err)) {
+ struct nilfs_super_block **sbp = nilfs->ns_sbp;
+ int blocksize;
+
+ if (err != -EINVAL)
+ goto scan_error;
+
+ if (!nilfs_valid_sb(sbp[1])) {
+ printk(KERN_WARNING
+ "NILFS warning: unable to fall back to spare"
+ "super block\n");
+ goto scan_error;
+ }
+ printk(KERN_INFO
+ "NILFS: try rollback from an earlier position\n");
+
+ /*
+ * restore super block with its spare and reconfigure
+ * relevant states of the nilfs object.
+ */
+ memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
+ nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed);
+ nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
+
+ /* verify consistency between two super blocks */
+ blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size);
+ if (blocksize != nilfs->ns_blocksize) {
+ printk(KERN_WARNING
+ "NILFS warning: blocksize differs between "
+ "two super blocks (%d != %d)\n",
+ blocksize, nilfs->ns_blocksize);
+ goto scan_error;
+ }
+
+ err = nilfs_store_log_cursor(nilfs, sbp[0]);
+ if (err)
+ goto scan_error;
+
+ /* drop clean flag to allow roll-forward and recovery */
+ nilfs->ns_mount_state &= ~NILFS_VALID_FS;
+ valid_fs = 0;
+
+ err = nilfs_search_super_root(nilfs, &ri);
+ if (err)
+ goto scan_error;
+ }
+
+ err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root);
+ if (unlikely(err)) {
+ printk(KERN_ERR "NILFS: error loading super root.\n");
+ goto failed;
+ }
+
+ if (valid_fs)
+ goto skip_recovery;
+
+ if (s_flags & MS_RDONLY) {
+ __u64 features;
+
+ if (nilfs_test_opt(nilfs, NORECOVERY)) {
+ printk(KERN_INFO "NILFS: norecovery option specified. "
+ "skipping roll-forward recovery\n");
+ goto skip_recovery;
+ }
+ features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
+ ~NILFS_FEATURE_COMPAT_RO_SUPP;
+ if (features) {
+ printk(KERN_ERR "NILFS: couldn't proceed with "
+ "recovery because of unsupported optional "
+ "features (%llx)\n",
+ (unsigned long long)features);
+ err = -EROFS;
+ goto failed_unload;
+ }
+ if (really_read_only) {
+ printk(KERN_ERR "NILFS: write access "
+ "unavailable, cannot proceed.\n");
+ err = -EROFS;
+ goto failed_unload;
+ }
+ sb->s_flags &= ~MS_RDONLY;
+ } else if (nilfs_test_opt(nilfs, NORECOVERY)) {
+ printk(KERN_ERR "NILFS: recovery cancelled because norecovery "
+ "option was specified for a read/write mount\n");
+ err = -EINVAL;
+ goto failed_unload;
+ }
+
+ err = nilfs_salvage_orphan_logs(nilfs, sb, &ri);
+ if (err)
+ goto failed_unload;
+
+ down_write(&nilfs->ns_sem);
+ nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */
+ err = nilfs_cleanup_super(sb);
+ up_write(&nilfs->ns_sem);
+
+ if (err) {
+ printk(KERN_ERR "NILFS: failed to update super block. "
+ "recovery unfinished.\n");
+ goto failed_unload;
+ }
+ printk(KERN_INFO "NILFS: recovery complete.\n");
+
+ skip_recovery:
+ nilfs_clear_recovery_info(&ri);
+ sb->s_flags = s_flags;
+ return 0;
+
+ scan_error:
+ printk(KERN_ERR "NILFS: error searching super root.\n");
+ goto failed;
+
+ failed_unload:
+ iput(nilfs->ns_cpfile);
+ iput(nilfs->ns_sufile);
+ iput(nilfs->ns_dat);
+
+ failed:
+ nilfs_clear_recovery_info(&ri);
+ sb->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;
+}
+
+/**
+ * nilfs_nrsvsegs - calculate the number of reserved segments
+ * @nilfs: nilfs object
+ * @nsegs: total number of segments
+ */
+unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs)
+{
+ return max_t(unsigned long, NILFS_MIN_NRSVSEGS,
+ DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage,
+ 100));
+}
+
+void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs)
+{
+ nilfs->ns_nsegments = nsegs;
+ nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs);
+}
+
+static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
+ struct nilfs_super_block *sbp)
+{
+ if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) {
+ printk(KERN_ERR "NILFS: unsupported revision "
+ "(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_sbsize = le16_to_cpu(sbp->s_bytes);
+ if (nilfs->ns_sbsize > BLOCK_SIZE)
+ 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_r_segments_percentage =
+ le32_to_cpu(sbp->s_r_segments_percentage);
+ if (nilfs->ns_r_segments_percentage < 1 ||
+ nilfs->ns_r_segments_percentage > 99) {
+ printk(KERN_ERR "NILFS: invalid reserved segments percentage.\n");
+ return -EINVAL;
+ }
+
+ nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments));
+ nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
+ return 0;
+}
+
+static int nilfs_valid_sb(struct nilfs_super_block *sbp)
+{
+ static unsigned char sum[4];
+ const int sumoff = offsetof(struct nilfs_super_block, s_sum);
+ size_t bytes;
+ u32 crc;
+
+ if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC)
+ return 0;
+ bytes = le16_to_cpu(sbp->s_bytes);
+ if (bytes > BLOCK_SIZE)
+ return 0;
+ crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp,
+ sumoff);
+ crc = crc32_le(crc, sum, 4);
+ crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4,
+ bytes - sumoff - 4);
+ return crc == le32_to_cpu(sbp->s_sum);
+}
+
+static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset)
+{
+ return offset < ((le64_to_cpu(sbp->s_nsegments) *
+ le32_to_cpu(sbp->s_blocks_per_segment)) <<
+ (le32_to_cpu(sbp->s_log_block_size) + 10));
+}
+
+static void nilfs_release_super_block(struct the_nilfs *nilfs)
+{
+ int i;
+
+ for (i = 0; i < 2; i++) {
+ if (nilfs->ns_sbp[i]) {
+ brelse(nilfs->ns_sbh[i]);
+ nilfs->ns_sbh[i] = NULL;
+ nilfs->ns_sbp[i] = NULL;
+ }
+ }
+}
+
+void nilfs_fall_back_super_block(struct the_nilfs *nilfs)
+{
+ brelse(nilfs->ns_sbh[0]);
+ nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
+ nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
+ nilfs->ns_sbh[1] = NULL;
+ nilfs->ns_sbp[1] = NULL;
+}
+
+void nilfs_swap_super_block(struct the_nilfs *nilfs)
+{
+ struct buffer_head *tsbh = nilfs->ns_sbh[0];
+ struct nilfs_super_block *tsbp = nilfs->ns_sbp[0];
+
+ nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
+ nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
+ nilfs->ns_sbh[1] = tsbh;
+ nilfs->ns_sbp[1] = tsbp;
+}
+
+static int nilfs_load_super_block(struct the_nilfs *nilfs,
+ struct super_block *sb, int blocksize,
+ struct nilfs_super_block **sbpp)
+{
+ struct nilfs_super_block **sbp = nilfs->ns_sbp;
+ struct buffer_head **sbh = nilfs->ns_sbh;
+ u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size);
+ int valid[2], swp = 0;
+
+ sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,
+ &sbh[0]);
+ sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]);
+
+ if (!sbp[0]) {
+ if (!sbp[1]) {
+ printk(KERN_ERR "NILFS: unable to read superblock\n");
+ return -EIO;
+ }
+ printk(KERN_WARNING
+ "NILFS warning: unable to read primary superblock "
+ "(blocksize = %d)\n", blocksize);
+ } else if (!sbp[1]) {
+ printk(KERN_WARNING
+ "NILFS warning: unable to read secondary superblock "
+ "(blocksize = %d)\n", blocksize);
+ }
+
+ /*
+ * Compare two super blocks and set 1 in swp if the secondary
+ * super block is valid and newer. Otherwise, set 0 in swp.
+ */
+ valid[0] = nilfs_valid_sb(sbp[0]);
+ valid[1] = nilfs_valid_sb(sbp[1]);
+ swp = valid[1] && (!valid[0] ||
+ le64_to_cpu(sbp[1]->s_last_cno) >
+ le64_to_cpu(sbp[0]->s_last_cno));
+
+ if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) {
+ brelse(sbh[1]);
+ sbh[1] = NULL;
+ sbp[1] = NULL;
+ valid[1] = 0;
+ swp = 0;
+ }
+ if (!valid[swp]) {
+ nilfs_release_super_block(nilfs);
+ printk(KERN_ERR "NILFS: Can't find nilfs on dev %s.\n",
+ sb->s_id);
+ return -EINVAL;
+ }
+
+ if (!valid[!swp])
+ printk(KERN_WARNING "NILFS warning: broken superblock. "
+ "using spare superblock (blocksize = %d).\n", blocksize);
+ if (swp)
+ nilfs_swap_super_block(nilfs);
+
+ nilfs->ns_sbwcount = 0;
+ nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
+ nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq);
+ *sbpp = sbp[0];
+ return 0;
+}
+
+/**
+ * init_nilfs - initialize a NILFS instance.
+ * @nilfs: the_nilfs structure
+ * @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).
+ *
+ * Return Value: On success, 0 is returned. On error, a negative error
+ * code is returned.
+ */
+int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data)
+{
+ struct nilfs_super_block *sbp;
+ int blocksize;
+ int err;
+
+ down_write(&nilfs->ns_sem);
+
+ blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE);
+ if (!blocksize) {
+ printk(KERN_ERR "NILFS: unable to set blocksize\n");
+ err = -EINVAL;
+ goto out;
+ }
+ err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
+ if (err)
+ goto out;
+
+ err = nilfs_store_magic_and_option(sb, sbp, data);
+ if (err)
+ goto failed_sbh;
+
+ err = nilfs_check_feature_compatibility(sb, sbp);
+ if (err)
+ goto failed_sbh;
+
+ blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
+ if (blocksize < NILFS_MIN_BLOCK_SIZE ||
+ blocksize > NILFS_MAX_BLOCK_SIZE) {
+ printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
+ "filesystem blocksize %d\n", blocksize);
+ err = -EINVAL;
+ goto failed_sbh;
+ }
+ if (sb->s_blocksize != blocksize) {
+ int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
+
+ if (blocksize < hw_blocksize) {
+ printk(KERN_ERR
+ "NILFS: blocksize %d too small for device "
+ "(sector-size = %d).\n",
+ blocksize, hw_blocksize);
+ err = -EINVAL;
+ goto failed_sbh;
+ }
+ nilfs_release_super_block(nilfs);
+ sb_set_blocksize(sb, blocksize);
+
+ err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
+ if (err)
+ goto out;
+ /* not failed_sbh; sbh is released automatically
+ when reloading fails. */
+ }
+ nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
+ nilfs->ns_blocksize = blocksize;
+
+ get_random_bytes(&nilfs->ns_next_generation,
+ sizeof(nilfs->ns_next_generation));
+
+ err = nilfs_store_disk_layout(nilfs, 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);
+
+ err = nilfs_store_log_cursor(nilfs, sbp);
+ if (err)
+ goto failed_sbh;
+
+ set_nilfs_init(nilfs);
+ err = 0;
+ out:
+ up_write(&nilfs->ns_sem);
+ return err;
+
+ failed_sbh:
+ nilfs_release_super_block(nilfs);
+ goto out;
+}
+
+int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
+ size_t nsegs)
+{
+ sector_t seg_start, seg_end;
+ sector_t start = 0, nblocks = 0;
+ unsigned int sects_per_block;
+ __u64 *sn;
+ int ret = 0;
+
+ sects_per_block = (1 << nilfs->ns_blocksize_bits) /
+ bdev_logical_block_size(nilfs->ns_bdev);
+ for (sn = segnump; sn < segnump + nsegs; sn++) {
+ nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end);
+
+ if (!nblocks) {
+ start = seg_start;
+ nblocks = seg_end - seg_start + 1;
+ } else if (start + nblocks == seg_start) {
+ nblocks += seg_end - seg_start + 1;
+ } else {
+ ret = blkdev_issue_discard(nilfs->ns_bdev,
+ start * sects_per_block,
+ nblocks * sects_per_block,
+ GFP_NOFS, 0);
+ if (ret < 0)
+ return ret;
+ nblocks = 0;
+ }
+ }
+ if (nblocks)
+ ret = blkdev_issue_discard(nilfs->ns_bdev,
+ start * sects_per_block,
+ nblocks * sects_per_block,
+ GFP_NOFS, 0);
+ return ret;
+}
+
+int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
+{
+ unsigned long ncleansegs;
+
+ down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
+ ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
+ up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
+ *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
+ return 0;
+}
+
+int nilfs_near_disk_full(struct the_nilfs *nilfs)
+{
+ unsigned long ncleansegs, nincsegs;
+
+ ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
+ nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
+ nilfs->ns_blocks_per_segment + 1;
+
+ return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs;
+}
+
+struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno)
+{
+ struct rb_node *n;
+ struct nilfs_root *root;
+
+ spin_lock(&nilfs->ns_cptree_lock);
+ n = nilfs->ns_cptree.rb_node;
+ while (n) {
+ root = rb_entry(n, struct nilfs_root, rb_node);
+
+ if (cno < root->cno) {
+ n = n->rb_left;
+ } else if (cno > root->cno) {
+ n = n->rb_right;
+ } else {
+ atomic_inc(&root->count);
+ spin_unlock(&nilfs->ns_cptree_lock);
+ return root;
+ }
+ }
+ spin_unlock(&nilfs->ns_cptree_lock);
+
+ return NULL;
+}
+
+struct nilfs_root *
+nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno)
+{
+ struct rb_node **p, *parent;
+ struct nilfs_root *root, *new;
+
+ root = nilfs_lookup_root(nilfs, cno);
+ if (root)
+ return root;
+
+ new = kmalloc(sizeof(*root), GFP_KERNEL);
+ if (!new)
+ return NULL;
+
+ spin_lock(&nilfs->ns_cptree_lock);
+
+ p = &nilfs->ns_cptree.rb_node;
+ parent = NULL;
+
+ while (*p) {
+ parent = *p;
+ root = rb_entry(parent, struct nilfs_root, rb_node);
+
+ if (cno < root->cno) {
+ p = &(*p)->rb_left;
+ } else if (cno > root->cno) {
+ p = &(*p)->rb_right;
+ } else {
+ atomic_inc(&root->count);
+ spin_unlock(&nilfs->ns_cptree_lock);
+ kfree(new);
+ return root;
+ }
+ }
+
+ new->cno = cno;
+ new->ifile = NULL;
+ new->nilfs = nilfs;
+ atomic_set(&new->count, 1);
+ atomic_set(&new->inodes_count, 0);
+ atomic_set(&new->blocks_count, 0);
+
+ rb_link_node(&new->rb_node, parent, p);
+ rb_insert_color(&new->rb_node, &nilfs->ns_cptree);
+
+ spin_unlock(&nilfs->ns_cptree_lock);
+
+ return new;
+}
+
+void nilfs_put_root(struct nilfs_root *root)
+{
+ if (atomic_dec_and_test(&root->count)) {
+ struct the_nilfs *nilfs = root->nilfs;
+
+ spin_lock(&nilfs->ns_cptree_lock);
+ rb_erase(&root->rb_node, &nilfs->ns_cptree);
+ spin_unlock(&nilfs->ns_cptree_lock);
+ if (root->ifile)
+ iput(root->ifile);
+
+ kfree(root);
+ }
+}