--- /dev/null
+/*
+ * recovery.c - NILFS recovery logic
+ *
+ * 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/blkdev.h>
+#include <linux/swap.h>
+#include <linux/crc32.h>
+#include "nilfs.h"
+#include "segment.h"
+#include "sufile.h"
+#include "page.h"
+#include "seglist.h"
+#include "segbuf.h"
+
+/*
+ * Segment check result
+ */
+enum {
+ NILFS_SEG_VALID,
+ NILFS_SEG_NO_SUPER_ROOT,
+ NILFS_SEG_FAIL_IO,
+ NILFS_SEG_FAIL_MAGIC,
+ NILFS_SEG_FAIL_SEQ,
+ NILFS_SEG_FAIL_CHECKSUM_SEGSUM,
+ NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT,
+ NILFS_SEG_FAIL_CHECKSUM_FULL,
+ NILFS_SEG_FAIL_CONSISTENCY,
+};
+
+/* work structure for recovery */
+struct nilfs_recovery_block {
+ ino_t ino; /* Inode number of the file that this block
+ belongs to */
+ sector_t blocknr; /* block number */
+ __u64 vblocknr; /* virtual block number */
+ unsigned long blkoff; /* File offset of the data block (per block) */
+ struct list_head list;
+};
+
+
+static int nilfs_warn_segment_error(int err)
+{
+ switch (err) {
+ case NILFS_SEG_FAIL_IO:
+ printk(KERN_WARNING
+ "NILFS warning: I/O error on loading last segment\n");
+ return -EIO;
+ case NILFS_SEG_FAIL_MAGIC:
+ printk(KERN_WARNING
+ "NILFS warning: Segment magic number invalid\n");
+ break;
+ case NILFS_SEG_FAIL_SEQ:
+ printk(KERN_WARNING
+ "NILFS warning: Sequence number mismatch\n");
+ break;
+ case NILFS_SEG_FAIL_CHECKSUM_SEGSUM:
+ printk(KERN_WARNING
+ "NILFS warning: Checksum error in segment summary\n");
+ break;
+ case NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT:
+ printk(KERN_WARNING
+ "NILFS warning: Checksum error in super root\n");
+ break;
+ case NILFS_SEG_FAIL_CHECKSUM_FULL:
+ printk(KERN_WARNING
+ "NILFS warning: Checksum error in segment payload\n");
+ break;
+ case NILFS_SEG_FAIL_CONSISTENCY:
+ printk(KERN_WARNING
+ "NILFS warning: Inconsistent segment\n");
+ break;
+ case NILFS_SEG_NO_SUPER_ROOT:
+ printk(KERN_WARNING
+ "NILFS warning: No super root in the last segment\n");
+ break;
+ case NILFS_SEG_VALID:
+ default:
+ BUG();
+ }
+ return -EINVAL;
+}
+
+static void store_segsum_info(struct nilfs_segsum_info *ssi,
+ struct nilfs_segment_summary *sum,
+ unsigned int blocksize)
+{
+ ssi->flags = le16_to_cpu(sum->ss_flags);
+ ssi->seg_seq = le64_to_cpu(sum->ss_seq);
+ ssi->ctime = le64_to_cpu(sum->ss_create);
+ ssi->next = le64_to_cpu(sum->ss_next);
+ ssi->nblocks = le32_to_cpu(sum->ss_nblocks);
+ ssi->nfinfo = le32_to_cpu(sum->ss_nfinfo);
+ ssi->sumbytes = le32_to_cpu(sum->ss_sumbytes);
+
+ ssi->nsumblk = DIV_ROUND_UP(ssi->sumbytes, blocksize);
+ ssi->nfileblk = ssi->nblocks - ssi->nsumblk - !!NILFS_SEG_HAS_SR(ssi);
+}
+
+/**
+ * calc_crc_cont - check CRC of blocks continuously
+ * @sbi: nilfs_sb_info
+ * @bhs: buffer head of start block
+ * @sum: place to store result
+ * @offset: offset bytes in the first block
+ * @check_bytes: number of bytes to be checked
+ * @start: DBN of start block
+ * @nblock: number of blocks to be checked
+ */
+static int calc_crc_cont(struct nilfs_sb_info *sbi, struct buffer_head *bhs,
+ u32 *sum, unsigned long offset, u64 check_bytes,
+ sector_t start, unsigned long nblock)
+{
+ unsigned long blocksize = sbi->s_super->s_blocksize;
+ unsigned long size;
+ u32 crc;
+
+ BUG_ON(offset >= blocksize);
+ check_bytes -= offset;
+ size = min_t(u64, check_bytes, blocksize - offset);
+ crc = crc32_le(sbi->s_nilfs->ns_crc_seed,
+ (unsigned char *)bhs->b_data + offset, size);
+ if (--nblock > 0) {
+ do {
+ struct buffer_head *bh
+ = sb_bread(sbi->s_super, ++start);
+ if (!bh)
+ return -EIO;
+ check_bytes -= size;
+ size = min_t(u64, check_bytes, blocksize);
+ crc = crc32_le(crc, bh->b_data, size);
+ brelse(bh);
+ } while (--nblock > 0);
+ }
+ *sum = crc;
+ return 0;
+}
+
+/**
+ * nilfs_read_super_root_block - read super root block
+ * @sb: super_block
+ * @sr_block: disk block number of the super root block
+ * @pbh: address of a buffer_head pointer to return super root buffer
+ * @check: CRC check flag
+ */
+int nilfs_read_super_root_block(struct super_block *sb, sector_t sr_block,
+ struct buffer_head **pbh, int check)
+{
+ struct buffer_head *bh_sr;
+ struct nilfs_super_root *sr;
+ u32 crc;
+ int ret;
+
+ *pbh = NULL;
+ bh_sr = sb_bread(sb, sr_block);
+ if (unlikely(!bh_sr)) {
+ ret = NILFS_SEG_FAIL_IO;
+ goto failed;
+ }
+
+ sr = (struct nilfs_super_root *)bh_sr->b_data;
+ if (check) {
+ unsigned bytes = le16_to_cpu(sr->sr_bytes);
+
+ if (bytes == 0 || bytes > sb->s_blocksize) {
+ ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT;
+ goto failed_bh;
+ }
+ if (calc_crc_cont(NILFS_SB(sb), bh_sr, &crc,
+ sizeof(sr->sr_sum), bytes, sr_block, 1)) {
+ ret = NILFS_SEG_FAIL_IO;
+ goto failed_bh;
+ }
+ if (crc != le32_to_cpu(sr->sr_sum)) {
+ ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT;
+ goto failed_bh;
+ }
+ }
+ *pbh = bh_sr;
+ return 0;
+
+ failed_bh:
+ brelse(bh_sr);
+
+ failed:
+ return nilfs_warn_segment_error(ret);
+}
+
+/**
+ * load_segment_summary - read segment summary of the specified partial segment
+ * @sbi: nilfs_sb_info
+ * @pseg_start: start disk block number of partial segment
+ * @seg_seq: sequence number requested
+ * @ssi: pointer to nilfs_segsum_info struct to store information
+ * @full_check: full check flag
+ * (0: only checks segment summary CRC, 1: data CRC)
+ */
+static int
+load_segment_summary(struct nilfs_sb_info *sbi, sector_t pseg_start,
+ u64 seg_seq, struct nilfs_segsum_info *ssi,
+ int full_check)
+{
+ struct buffer_head *bh_sum;
+ struct nilfs_segment_summary *sum;
+ unsigned long offset, nblock;
+ u64 check_bytes;
+ u32 crc, crc_sum;
+ int ret = NILFS_SEG_FAIL_IO;
+
+ bh_sum = sb_bread(sbi->s_super, pseg_start);
+ if (!bh_sum)
+ goto out;
+
+ sum = (struct nilfs_segment_summary *)bh_sum->b_data;
+
+ /* Check consistency of segment summary */
+ if (le32_to_cpu(sum->ss_magic) != NILFS_SEGSUM_MAGIC) {
+ ret = NILFS_SEG_FAIL_MAGIC;
+ goto failed;
+ }
+ store_segsum_info(ssi, sum, sbi->s_super->s_blocksize);
+ if (seg_seq != ssi->seg_seq) {
+ ret = NILFS_SEG_FAIL_SEQ;
+ goto failed;
+ }
+ if (full_check) {
+ offset = sizeof(sum->ss_datasum);
+ check_bytes =
+ ((u64)ssi->nblocks << sbi->s_super->s_blocksize_bits);
+ nblock = ssi->nblocks;
+ crc_sum = le32_to_cpu(sum->ss_datasum);
+ ret = NILFS_SEG_FAIL_CHECKSUM_FULL;
+ } else { /* only checks segment summary */
+ offset = sizeof(sum->ss_datasum) + sizeof(sum->ss_sumsum);
+ check_bytes = ssi->sumbytes;
+ nblock = ssi->nsumblk;
+ crc_sum = le32_to_cpu(sum->ss_sumsum);
+ ret = NILFS_SEG_FAIL_CHECKSUM_SEGSUM;
+ }
+
+ if (unlikely(nblock == 0 ||
+ nblock > sbi->s_nilfs->ns_blocks_per_segment)) {
+ /* This limits the number of blocks read in the CRC check */
+ ret = NILFS_SEG_FAIL_CONSISTENCY;
+ goto failed;
+ }
+ if (calc_crc_cont(sbi, bh_sum, &crc, offset, check_bytes,
+ pseg_start, nblock)) {
+ ret = NILFS_SEG_FAIL_IO;
+ goto failed;
+ }
+ if (crc == crc_sum)
+ ret = 0;
+ failed:
+ brelse(bh_sum);
+ out:
+ return ret;
+}
+
+static void *segsum_get(struct super_block *sb, struct buffer_head **pbh,
+ unsigned int *offset, unsigned int bytes)
+{
+ void *ptr;
+ sector_t blocknr;
+
+ BUG_ON((*pbh)->b_size < *offset);
+ if (bytes > (*pbh)->b_size - *offset) {
+ blocknr = (*pbh)->b_blocknr;
+ brelse(*pbh);
+ *pbh = sb_bread(sb, blocknr + 1);
+ if (unlikely(!*pbh))
+ return NULL;
+ *offset = 0;
+ }
+ ptr = (*pbh)->b_data + *offset;
+ *offset += bytes;
+ return ptr;
+}
+
+static void segsum_skip(struct super_block *sb, struct buffer_head **pbh,
+ unsigned int *offset, unsigned int bytes,
+ unsigned long count)
+{
+ unsigned int rest_item_in_current_block
+ = ((*pbh)->b_size - *offset) / bytes;
+
+ if (count <= rest_item_in_current_block) {
+ *offset += bytes * count;
+ } else {
+ sector_t blocknr = (*pbh)->b_blocknr;
+ unsigned int nitem_per_block = (*pbh)->b_size / bytes;
+ unsigned int bcnt;
+
+ count -= rest_item_in_current_block;
+ bcnt = DIV_ROUND_UP(count, nitem_per_block);
+ *offset = bytes * (count - (bcnt - 1) * nitem_per_block);
+
+ brelse(*pbh);
+ *pbh = sb_bread(sb, blocknr + bcnt);
+ }
+}
+
+static int
+collect_blocks_from_segsum(struct nilfs_sb_info *sbi, sector_t sum_blocknr,
+ struct nilfs_segsum_info *ssi,
+ struct list_head *head)
+{
+ struct buffer_head *bh;
+ unsigned int offset;
+ unsigned long nfinfo = ssi->nfinfo;
+ sector_t blocknr = sum_blocknr + ssi->nsumblk;
+ ino_t ino;
+ int err = -EIO;
+
+ if (!nfinfo)
+ return 0;
+
+ bh = sb_bread(sbi->s_super, sum_blocknr);
+ if (unlikely(!bh))
+ goto out;
+
+ offset = le16_to_cpu(
+ ((struct nilfs_segment_summary *)bh->b_data)->ss_bytes);
+ for (;;) {
+ unsigned long nblocks, ndatablk, nnodeblk;
+ struct nilfs_finfo *finfo;
+
+ finfo = segsum_get(sbi->s_super, &bh, &offset, sizeof(*finfo));
+ if (unlikely(!finfo))
+ goto out;
+
+ ino = le64_to_cpu(finfo->fi_ino);
+ nblocks = le32_to_cpu(finfo->fi_nblocks);
+ ndatablk = le32_to_cpu(finfo->fi_ndatablk);
+ nnodeblk = nblocks - ndatablk;
+
+ while (ndatablk-- > 0) {
+ struct nilfs_recovery_block *rb;
+ struct nilfs_binfo_v *binfo;
+
+ binfo = segsum_get(sbi->s_super, &bh, &offset,
+ sizeof(*binfo));
+ if (unlikely(!binfo))
+ goto out;
+
+ rb = kmalloc(sizeof(*rb), GFP_NOFS);
+ if (unlikely(!rb)) {
+ err = -ENOMEM;
+ goto out;
+ }
+ rb->ino = ino;
+ rb->blocknr = blocknr++;
+ rb->vblocknr = le64_to_cpu(binfo->bi_vblocknr);
+ rb->blkoff = le64_to_cpu(binfo->bi_blkoff);
+ /* INIT_LIST_HEAD(&rb->list); */
+ list_add_tail(&rb->list, head);
+ }
+ if (--nfinfo == 0)
+ break;
+ blocknr += nnodeblk; /* always 0 for the data sync segments */
+ segsum_skip(sbi->s_super, &bh, &offset, sizeof(__le64),
+ nnodeblk);
+ if (unlikely(!bh))
+ goto out;
+ }
+ err = 0;
+ out:
+ brelse(bh); /* brelse(NULL) is just ignored */
+ return err;
+}
+
+static void dispose_recovery_list(struct list_head *head)
+{
+ while (!list_empty(head)) {
+ struct nilfs_recovery_block *rb
+ = list_entry(head->next,
+ struct nilfs_recovery_block, list);
+ list_del(&rb->list);
+ kfree(rb);
+ }
+}
+
+void nilfs_dispose_segment_list(struct list_head *head)
+{
+ while (!list_empty(head)) {
+ struct nilfs_segment_entry *ent
+ = list_entry(head->next,
+ struct nilfs_segment_entry, list);
+ list_del(&ent->list);
+ nilfs_free_segment_entry(ent);
+ }
+}
+
+static int nilfs_prepare_segment_for_recovery(struct the_nilfs *nilfs,
+ struct nilfs_recovery_info *ri)
+{
+ struct list_head *head = &ri->ri_used_segments;
+ struct nilfs_segment_entry *ent, *n;
+ struct inode *sufile = nilfs->ns_sufile;
+ __u64 segnum[4];
+ int err;
+ int i;
+
+ segnum[0] = nilfs->ns_segnum;
+ segnum[1] = nilfs->ns_nextnum;
+ segnum[2] = ri->ri_segnum;
+ segnum[3] = ri->ri_nextnum;
+
+ /*
+ * Releasing the next segment of the latest super root.
+ * The next segment is invalidated by this recovery.
+ */
+ err = nilfs_sufile_free(sufile, segnum[1]);
+ if (unlikely(err))
+ goto failed;
+
+ err = -ENOMEM;
+ for (i = 1; i < 4; i++) {
+ ent = nilfs_alloc_segment_entry(segnum[i]);
+ if (unlikely(!ent))
+ goto failed;
+ list_add_tail(&ent->list, head);
+ }
+
+ /*
+ * Collecting segments written after the latest super root.
+ * These are marked volatile active, and won't be reallocated in
+ * the next construction.
+ */
+ list_for_each_entry_safe(ent, n, head, list) {
+ if (ent->segnum == segnum[0]) {
+ list_del(&ent->list);
+ nilfs_free_segment_entry(ent);
+ continue;
+ }
+ err = nilfs_open_segment_entry(ent, sufile);
+ if (unlikely(err))
+ goto failed;
+ if (nilfs_segment_usage_clean(ent->raw_su)) {
+ nilfs_segment_usage_set_volatile_active(ent->raw_su);
+ /* Keep it open */
+ } else {
+ /* Removing duplicated entries */
+ list_del(&ent->list);
+ nilfs_close_segment_entry(ent, sufile);
+ nilfs_free_segment_entry(ent);
+ }
+ }
+ list_splice_init(head, nilfs->ns_used_segments.prev);
+
+ /*
+ * The segment having the latest super root is active, and
+ * should be deactivated on the next construction for recovery.
+ */
+ err = -ENOMEM;
+ ent = nilfs_alloc_segment_entry(segnum[0]);
+ if (unlikely(!ent))
+ goto failed;
+ list_add_tail(&ent->list, &ri->ri_used_segments);
+
+ /* Allocate new segments for recovery */
+ err = nilfs_sufile_alloc(sufile, &segnum[0]);
+ if (unlikely(err))
+ goto failed;
+
+ nilfs->ns_pseg_offset = 0;
+ nilfs->ns_seg_seq = ri->ri_seq + 2;
+ nilfs->ns_nextnum = nilfs->ns_segnum = segnum[0];
+ return 0;
+
+ failed:
+ /* No need to recover sufile because it will be destroyed on error */
+ return err;
+}
+
+static int nilfs_recovery_copy_block(struct nilfs_sb_info *sbi,
+ struct nilfs_recovery_block *rb,
+ struct page *page)
+{
+ struct buffer_head *bh_org;
+ void *kaddr;
+
+ bh_org = sb_bread(sbi->s_super, rb->blocknr);
+ if (unlikely(!bh_org))
+ return -EIO;
+
+ kaddr = kmap_atomic(page, KM_USER0);
+ memcpy(kaddr + bh_offset(bh_org), bh_org->b_data, bh_org->b_size);
+ kunmap_atomic(kaddr, KM_USER0);
+ brelse(bh_org);
+ return 0;
+}
+
+static int recover_dsync_blocks(struct nilfs_sb_info *sbi,
+ struct list_head *head,
+ unsigned long *nr_salvaged_blocks)
+{
+ struct inode *inode;
+ struct nilfs_recovery_block *rb, *n;
+ unsigned blocksize = sbi->s_super->s_blocksize;
+ struct page *page;
+ loff_t pos;
+ int err = 0, err2 = 0;
+
+ list_for_each_entry_safe(rb, n, head, list) {
+ inode = nilfs_iget(sbi->s_super, rb->ino);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ inode = NULL;
+ goto failed_inode;
+ }
+
+ pos = rb->blkoff << inode->i_blkbits;
+ page = NULL;
+ err = block_write_begin(NULL, inode->i_mapping, pos, blocksize,
+ 0, &page, NULL, nilfs_get_block);
+ if (unlikely(err))
+ goto failed_inode;
+
+ err = nilfs_recovery_copy_block(sbi, rb, page);
+ if (unlikely(err))
+ goto failed_page;
+
+ err = nilfs_set_file_dirty(sbi, inode, 1);
+ if (unlikely(err))
+ goto failed_page;
+
+ block_write_end(NULL, inode->i_mapping, pos, blocksize,
+ blocksize, page, NULL);
+
+ unlock_page(page);
+ page_cache_release(page);
+
+ (*nr_salvaged_blocks)++;
+ goto next;
+
+ failed_page:
+ unlock_page(page);
+ page_cache_release(page);
+
+ failed_inode:
+ printk(KERN_WARNING
+ "NILFS warning: error recovering data block "
+ "(err=%d, ino=%lu, block-offset=%llu)\n",
+ err, rb->ino, (unsigned long long)rb->blkoff);
+ if (!err2)
+ err2 = err;
+ next:
+ iput(inode); /* iput(NULL) is just ignored */
+ list_del_init(&rb->list);
+ kfree(rb);
+ }
+ return err2;
+}
+
+/**
+ * nilfs_do_roll_forward - salvage logical segments newer than the latest
+ * checkpoint
+ * @sbi: nilfs_sb_info
+ * @nilfs: the_nilfs
+ * @ri: pointer to a nilfs_recovery_info
+ */
+static int nilfs_do_roll_forward(struct the_nilfs *nilfs,
+ struct nilfs_sb_info *sbi,
+ struct nilfs_recovery_info *ri)
+{
+ struct nilfs_segsum_info ssi;
+ sector_t pseg_start;
+ sector_t seg_start, seg_end; /* Starting/ending DBN of full segment */
+ unsigned long nsalvaged_blocks = 0;
+ u64 seg_seq;
+ __u64 segnum, nextnum = 0;
+ int empty_seg = 0;
+ int err = 0, ret;
+ LIST_HEAD(dsync_blocks); /* list of data blocks to be recovered */
+ enum {
+ RF_INIT_ST,
+ RF_DSYNC_ST, /* scanning data-sync segments */
+ };
+ int state = RF_INIT_ST;
+
+ nilfs_attach_writer(nilfs, sbi);
+ pseg_start = ri->ri_lsegs_start;
+ seg_seq = ri->ri_lsegs_start_seq;
+ segnum = nilfs_get_segnum_of_block(nilfs, pseg_start);
+ nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
+
+ while (segnum != ri->ri_segnum || pseg_start <= ri->ri_pseg_start) {
+
+ ret = load_segment_summary(sbi, pseg_start, seg_seq, &ssi, 1);
+ if (ret) {
+ if (ret == NILFS_SEG_FAIL_IO) {
+ err = -EIO;
+ goto failed;
+ }
+ goto strayed;
+ }
+ if (unlikely(NILFS_SEG_HAS_SR(&ssi)))
+ goto confused;
+
+ /* Found a valid partial segment; do recovery actions */
+ nextnum = nilfs_get_segnum_of_block(nilfs, ssi.next);
+ empty_seg = 0;
+ nilfs->ns_ctime = ssi.ctime;
+ if (!(ssi.flags & NILFS_SS_GC))
+ nilfs->ns_nongc_ctime = ssi.ctime;
+
+ switch (state) {
+ case RF_INIT_ST:
+ if (!NILFS_SEG_LOGBGN(&ssi) || !NILFS_SEG_DSYNC(&ssi))
+ goto try_next_pseg;
+ state = RF_DSYNC_ST;
+ /* Fall through */
+ case RF_DSYNC_ST:
+ if (!NILFS_SEG_DSYNC(&ssi))
+ goto confused;
+
+ err = collect_blocks_from_segsum(
+ sbi, pseg_start, &ssi, &dsync_blocks);
+ if (unlikely(err))
+ goto failed;
+ if (NILFS_SEG_LOGEND(&ssi)) {
+ err = recover_dsync_blocks(
+ sbi, &dsync_blocks, &nsalvaged_blocks);
+ if (unlikely(err))
+ goto failed;
+ state = RF_INIT_ST;
+ }
+ break; /* Fall through to try_next_pseg */
+ }
+
+ try_next_pseg:
+ if (pseg_start == ri->ri_lsegs_end)
+ break;
+ pseg_start += ssi.nblocks;
+ if (pseg_start < seg_end)
+ continue;
+ goto feed_segment;
+
+ strayed:
+ if (pseg_start == ri->ri_lsegs_end)
+ break;
+
+ feed_segment:
+ /* Looking to the next full segment */
+ if (empty_seg++)
+ break;
+ seg_seq++;
+ segnum = nextnum;
+ nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
+ pseg_start = seg_start;
+ }
+
+ if (nsalvaged_blocks) {
+ printk(KERN_INFO "NILFS (device %s): salvaged %lu blocks\n",
+ sbi->s_super->s_id, nsalvaged_blocks);
+ ri->ri_need_recovery = NILFS_RECOVERY_ROLLFORWARD_DONE;
+ }
+ out:
+ dispose_recovery_list(&dsync_blocks);
+ nilfs_detach_writer(sbi->s_nilfs, sbi);
+ return err;
+
+ confused:
+ err = -EINVAL;
+ failed:
+ printk(KERN_ERR
+ "NILFS (device %s): Error roll-forwarding "
+ "(err=%d, pseg block=%llu). ",
+ sbi->s_super->s_id, err, (unsigned long long)pseg_start);
+ goto out;
+}
+
+static void nilfs_finish_roll_forward(struct the_nilfs *nilfs,
+ struct nilfs_sb_info *sbi,
+ struct nilfs_recovery_info *ri)
+{
+ struct buffer_head *bh;
+ int err;
+
+ if (nilfs_get_segnum_of_block(nilfs, ri->ri_lsegs_start) !=
+ nilfs_get_segnum_of_block(nilfs, ri->ri_super_root))
+ return;
+
+ bh = sb_getblk(sbi->s_super, ri->ri_lsegs_start);
+ BUG_ON(!bh);
+ memset(bh->b_data, 0, bh->b_size);
+ set_buffer_dirty(bh);
+ err = sync_dirty_buffer(bh);
+ if (unlikely(err))
+ printk(KERN_WARNING
+ "NILFS warning: buffer sync write failed during "
+ "post-cleaning of recovery.\n");
+ brelse(bh);
+}
+
+/**
+ * nilfs_recover_logical_segments - salvage logical segments written after
+ * the latest super root
+ * @nilfs: the_nilfs
+ * @sbi: nilfs_sb_info
+ * @ri: pointer to a nilfs_recovery_info struct to store search results.
+ *
+ * Return Value: On success, 0 is returned. On error, one of the following
+ * negative error code is returned.
+ *
+ * %-EINVAL - Inconsistent filesystem state.
+ *
+ * %-EIO - I/O error
+ *
+ * %-ENOSPC - No space left on device (only in a panic state).
+ *
+ * %-ERESTARTSYS - Interrupted.
+ *
+ * %-ENOMEM - Insufficient memory available.
+ */
+int nilfs_recover_logical_segments(struct the_nilfs *nilfs,
+ struct nilfs_sb_info *sbi,
+ struct nilfs_recovery_info *ri)
+{
+ int err;
+
+ if (ri->ri_lsegs_start == 0 || ri->ri_lsegs_end == 0)
+ return 0;
+
+ err = nilfs_attach_checkpoint(sbi, ri->ri_cno);
+ if (unlikely(err)) {
+ printk(KERN_ERR
+ "NILFS: error loading the latest checkpoint.\n");
+ return err;
+ }
+
+ err = nilfs_do_roll_forward(nilfs, sbi, ri);
+ if (unlikely(err))
+ goto failed;
+
+ if (ri->ri_need_recovery == NILFS_RECOVERY_ROLLFORWARD_DONE) {
+ err = nilfs_prepare_segment_for_recovery(nilfs, ri);
+ if (unlikely(err)) {
+ printk(KERN_ERR "NILFS: Error preparing segments for "
+ "recovery.\n");
+ goto failed;
+ }
+
+ err = nilfs_attach_segment_constructor(sbi, ri);
+ if (unlikely(err))
+ goto failed;
+
+ set_nilfs_discontinued(nilfs);
+ err = nilfs_construct_segment(sbi->s_super);
+ nilfs_detach_segment_constructor(sbi);
+
+ if (unlikely(err)) {
+ printk(KERN_ERR "NILFS: Oops! recovery failed. "
+ "(err=%d)\n", err);
+ goto failed;
+ }
+
+ nilfs_finish_roll_forward(nilfs, sbi, ri);
+ }
+
+ nilfs_detach_checkpoint(sbi);
+ return 0;
+
+ failed:
+ nilfs_detach_checkpoint(sbi);
+ nilfs_mdt_clear(nilfs->ns_cpfile);
+ nilfs_mdt_clear(nilfs->ns_sufile);
+ nilfs_mdt_clear(nilfs->ns_dat);
+ return err;
+}
+
+/**
+ * nilfs_search_super_root - search the latest valid super root
+ * @nilfs: the_nilfs
+ * @sbi: nilfs_sb_info
+ * @ri: pointer to a nilfs_recovery_info struct to store search results.
+ *
+ * nilfs_search_super_root() looks for the latest super-root from a partial
+ * segment pointed by the superblock. It sets up struct the_nilfs through
+ * this search. It fills nilfs_recovery_info (ri) required for recovery.
+ *
+ * Return Value: On success, 0 is returned. On error, one of the following
+ * negative error code is returned.
+ *
+ * %-EINVAL - No valid segment found
+ *
+ * %-EIO - I/O error
+ */
+int nilfs_search_super_root(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi,
+ struct nilfs_recovery_info *ri)
+{
+ struct nilfs_segsum_info ssi;
+ sector_t pseg_start, pseg_end, sr_pseg_start = 0;
+ sector_t seg_start, seg_end; /* range of full segment (block number) */
+ u64 seg_seq;
+ __u64 segnum, nextnum = 0;
+ __u64 cno;
+ struct nilfs_segment_entry *ent;
+ LIST_HEAD(segments);
+ int empty_seg = 0, scan_newer = 0;
+ int ret;
+
+ pseg_start = nilfs->ns_last_pseg;
+ seg_seq = nilfs->ns_last_seq;
+ cno = nilfs->ns_last_cno;
+ segnum = nilfs_get_segnum_of_block(nilfs, pseg_start);
+
+ /* Calculate range of segment */
+ nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
+
+ for (;;) {
+ /* Load segment summary */
+ ret = load_segment_summary(sbi, pseg_start, seg_seq, &ssi, 1);
+ if (ret) {
+ if (ret == NILFS_SEG_FAIL_IO)
+ goto failed;
+ goto strayed;
+ }
+ pseg_end = pseg_start + ssi.nblocks - 1;
+ if (unlikely(pseg_end > seg_end)) {
+ ret = NILFS_SEG_FAIL_CONSISTENCY;
+ goto strayed;
+ }
+
+ /* A valid partial segment */
+ ri->ri_pseg_start = pseg_start;
+ ri->ri_seq = seg_seq;
+ ri->ri_segnum = segnum;
+ nextnum = nilfs_get_segnum_of_block(nilfs, ssi.next);
+ ri->ri_nextnum = nextnum;
+ empty_seg = 0;
+
+ if (!NILFS_SEG_HAS_SR(&ssi)) {
+ if (!scan_newer) {
+ /* This will never happen because a superblock
+ (last_segment) always points to a pseg
+ having a super root. */
+ ret = NILFS_SEG_FAIL_CONSISTENCY;
+ goto failed;
+ }
+ if (!ri->ri_lsegs_start && NILFS_SEG_LOGBGN(&ssi)) {
+ ri->ri_lsegs_start = pseg_start;
+ ri->ri_lsegs_start_seq = seg_seq;
+ }
+ if (NILFS_SEG_LOGEND(&ssi))
+ ri->ri_lsegs_end = pseg_start;
+ goto try_next_pseg;
+ }
+
+ /* A valid super root was found. */
+ ri->ri_cno = cno++;
+ ri->ri_super_root = pseg_end;
+ ri->ri_lsegs_start = ri->ri_lsegs_end = 0;
+
+ nilfs_dispose_segment_list(&segments);
+ nilfs->ns_pseg_offset = (sr_pseg_start = pseg_start)
+ + ssi.nblocks - seg_start;
+ nilfs->ns_seg_seq = seg_seq;
+ nilfs->ns_segnum = segnum;
+ nilfs->ns_cno = cno; /* nilfs->ns_cno = ri->ri_cno + 1 */
+ nilfs->ns_ctime = ssi.ctime;
+ nilfs->ns_nextnum = nextnum;
+
+ if (scan_newer)
+ ri->ri_need_recovery = NILFS_RECOVERY_SR_UPDATED;
+ else if (nilfs->ns_mount_state & NILFS_VALID_FS)
+ goto super_root_found;
+
+ scan_newer = 1;
+
+ /* reset region for roll-forward */
+ pseg_start += ssi.nblocks;
+ if (pseg_start < seg_end)
+ continue;
+ goto feed_segment;
+
+ try_next_pseg:
+ /* Standing on a course, or met an inconsistent state */
+ pseg_start += ssi.nblocks;
+ if (pseg_start < seg_end)
+ continue;
+ goto feed_segment;
+
+ strayed:
+ /* Off the trail */
+ if (!scan_newer)
+ /*
+ * This can happen if a checkpoint was written without
+ * barriers, or as a result of an I/O failure.
+ */
+ goto failed;
+
+ feed_segment:
+ /* Looking to the next full segment */
+ if (empty_seg++)
+ goto super_root_found; /* found a valid super root */
+
+ ent = nilfs_alloc_segment_entry(segnum);
+ if (unlikely(!ent)) {
+ ret = -ENOMEM;
+ goto failed;
+ }
+ list_add_tail(&ent->list, &segments);
+
+ seg_seq++;
+ segnum = nextnum;
+ nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end);
+ pseg_start = seg_start;
+ }
+
+ super_root_found:
+ /* Updating pointers relating to the latest checkpoint */
+ list_splice(&segments, ri->ri_used_segments.prev);
+ nilfs->ns_last_pseg = sr_pseg_start;
+ nilfs->ns_last_seq = nilfs->ns_seg_seq;
+ nilfs->ns_last_cno = ri->ri_cno;
+ return 0;
+
+ failed:
+ nilfs_dispose_segment_list(&segments);
+ return (ret < 0) ? ret : nilfs_warn_segment_error(ret);
+}
projects / users / willy / pagecache.git / commitdiff