978 lines
		
	
	
		
			25 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			978 lines
		
	
	
		
			25 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0+
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| /*
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|  * linux/fs/jbd2/recovery.c
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|  *
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|  * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
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|  *
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|  * Copyright 1999-2000 Red Hat Software --- All Rights Reserved
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|  *
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|  * Journal recovery routines for the generic filesystem journaling code;
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|  * part of the ext2fs journaling system.
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|  */
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| 
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| #ifndef __KERNEL__
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| #include "jfs_user.h"
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| #else
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| #include <linux/time.h>
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| #include <linux/fs.h>
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| #include <linux/jbd2.h>
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| #include <linux/errno.h>
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| #include <linux/crc32.h>
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| #include <linux/blkdev.h>
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| #include <linux/string_choices.h>
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| #endif
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| 
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| /*
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|  * Maintain information about the progress of the recovery job, so that
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|  * the different passes can carry information between them.
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|  */
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| struct recovery_info
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| {
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| 	tid_t		start_transaction;
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| 	tid_t		end_transaction;
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| 	unsigned long	head_block;
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| 
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| 	int		nr_replays;
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| 	int		nr_revokes;
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| 	int		nr_revoke_hits;
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| };
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| 
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| static int do_one_pass(journal_t *journal,
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| 				struct recovery_info *info, enum passtype pass);
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| static int scan_revoke_records(journal_t *, struct buffer_head *,
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| 				tid_t, struct recovery_info *);
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| 
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| #ifdef __KERNEL__
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| 
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| /* Release readahead buffers after use */
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| static void journal_brelse_array(struct buffer_head *b[], int n)
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| {
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| 	while (--n >= 0)
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| 		brelse (b[n]);
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| }
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| 
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| 
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| /*
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|  * When reading from the journal, we are going through the block device
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|  * layer directly and so there is no readahead being done for us.  We
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|  * need to implement any readahead ourselves if we want it to happen at
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|  * all.  Recovery is basically one long sequential read, so make sure we
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|  * do the IO in reasonably large chunks.
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|  *
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|  * This is not so critical that we need to be enormously clever about
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|  * the readahead size, though.  128K is a purely arbitrary, good-enough
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|  * fixed value.
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|  */
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| 
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| #define MAXBUF 8
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| static int do_readahead(journal_t *journal, unsigned int start)
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| {
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| 	int err;
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| 	unsigned int max, nbufs, next;
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| 	unsigned long long blocknr;
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| 	struct buffer_head *bh;
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| 
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| 	struct buffer_head * bufs[MAXBUF];
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| 
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| 	/* Do up to 128K of readahead */
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| 	max = start + (128 * 1024 / journal->j_blocksize);
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| 	if (max > journal->j_total_len)
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| 		max = journal->j_total_len;
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| 
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| 	/* Do the readahead itself.  We'll submit MAXBUF buffer_heads at
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| 	 * a time to the block device IO layer. */
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| 
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| 	nbufs = 0;
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| 
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| 	for (next = start; next < max; next++) {
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| 		err = jbd2_journal_bmap(journal, next, &blocknr);
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| 
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| 		if (err) {
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| 			printk(KERN_ERR "JBD2: bad block at offset %u\n",
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| 				next);
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| 			goto failed;
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| 		}
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| 
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| 		bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
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| 		if (!bh) {
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| 			err = -ENOMEM;
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| 			goto failed;
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| 		}
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| 
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| 		if (!buffer_uptodate(bh) && !buffer_locked(bh)) {
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| 			bufs[nbufs++] = bh;
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| 			if (nbufs == MAXBUF) {
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| 				bh_readahead_batch(nbufs, bufs, 0);
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| 				journal_brelse_array(bufs, nbufs);
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| 				nbufs = 0;
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| 			}
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| 		} else
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| 			brelse(bh);
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| 	}
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| 
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| 	if (nbufs)
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| 		bh_readahead_batch(nbufs, bufs, 0);
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| 	err = 0;
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| 
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| failed:
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| 	if (nbufs)
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| 		journal_brelse_array(bufs, nbufs);
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| 	return err;
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| }
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| 
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| #endif /* __KERNEL__ */
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| 
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| 
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| /*
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|  * Read a block from the journal
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|  */
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| 
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| static int jread(struct buffer_head **bhp, journal_t *journal,
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| 		 unsigned int offset)
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| {
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| 	int err;
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| 	unsigned long long blocknr;
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| 	struct buffer_head *bh;
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| 
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| 	*bhp = NULL;
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| 
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| 	if (offset >= journal->j_total_len) {
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| 		printk(KERN_ERR "JBD2: corrupted journal superblock\n");
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| 		return -EFSCORRUPTED;
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| 	}
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| 
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| 	err = jbd2_journal_bmap(journal, offset, &blocknr);
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| 
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| 	if (err) {
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| 		printk(KERN_ERR "JBD2: bad block at offset %u\n",
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| 			offset);
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| 		return err;
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| 	}
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| 
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| 	bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
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| 	if (!bh)
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| 		return -ENOMEM;
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| 
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| 	if (!buffer_uptodate(bh)) {
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| 		/*
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| 		 * If this is a brand new buffer, start readahead.
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| 		 * Otherwise, we assume we are already reading it.
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| 		 */
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| 		bool need_readahead = !buffer_req(bh);
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| 
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| 		bh_read_nowait(bh, 0);
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| 		if (need_readahead)
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| 			do_readahead(journal, offset);
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| 		wait_on_buffer(bh);
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| 	}
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| 
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| 	if (!buffer_uptodate(bh)) {
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| 		printk(KERN_ERR "JBD2: Failed to read block at offset %u\n",
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| 			offset);
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| 		brelse(bh);
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| 		return -EIO;
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| 	}
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| 
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| 	*bhp = bh;
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| 	return 0;
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| }
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| 
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| static int jbd2_descriptor_block_csum_verify(journal_t *j, void *buf)
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| {
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| 	struct jbd2_journal_block_tail *tail;
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| 	__be32 provided;
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| 	__u32 calculated;
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| 
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| 	if (!jbd2_journal_has_csum_v2or3(j))
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| 		return 1;
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| 
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| 	tail = (struct jbd2_journal_block_tail *)((char *)buf +
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| 		j->j_blocksize - sizeof(struct jbd2_journal_block_tail));
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| 	provided = tail->t_checksum;
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| 	tail->t_checksum = 0;
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| 	calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize);
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| 	tail->t_checksum = provided;
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| 
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| 	return provided == cpu_to_be32(calculated);
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| }
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| 
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| /*
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|  * Count the number of in-use tags in a journal descriptor block.
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|  */
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| 
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| static int count_tags(journal_t *journal, struct buffer_head *bh)
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| {
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| 	char *			tagp;
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| 	journal_block_tag_t	tag;
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| 	int			nr = 0, size = journal->j_blocksize;
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| 	int			tag_bytes = journal_tag_bytes(journal);
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| 
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| 	if (jbd2_journal_has_csum_v2or3(journal))
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| 		size -= sizeof(struct jbd2_journal_block_tail);
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| 
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| 	tagp = &bh->b_data[sizeof(journal_header_t)];
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| 
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| 	while ((tagp - bh->b_data + tag_bytes) <= size) {
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| 		memcpy(&tag, tagp, sizeof(tag));
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| 
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| 		nr++;
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| 		tagp += tag_bytes;
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| 		if (!(tag.t_flags & cpu_to_be16(JBD2_FLAG_SAME_UUID)))
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| 			tagp += 16;
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| 
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| 		if (tag.t_flags & cpu_to_be16(JBD2_FLAG_LAST_TAG))
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| 			break;
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| 	}
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| 
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| 	return nr;
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| }
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| 
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| 
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| /* Make sure we wrap around the log correctly! */
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| #define wrap(journal, var)						\
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| do {									\
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| 	if (var >= (journal)->j_last)					\
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| 		var -= ((journal)->j_last - (journal)->j_first);	\
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| } while (0)
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| 
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| static int fc_do_one_pass(journal_t *journal,
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| 			  struct recovery_info *info, enum passtype pass)
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| {
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| 	unsigned int expected_commit_id = info->end_transaction;
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| 	unsigned long next_fc_block;
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| 	struct buffer_head *bh;
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| 	int err = 0;
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| 
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| 	next_fc_block = journal->j_fc_first;
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| 	if (!journal->j_fc_replay_callback)
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| 		return 0;
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| 
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| 	while (next_fc_block <= journal->j_fc_last) {
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| 		jbd2_debug(3, "Fast commit replay: next block %ld\n",
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| 			  next_fc_block);
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| 		err = jread(&bh, journal, next_fc_block);
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| 		if (err) {
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| 			jbd2_debug(3, "Fast commit replay: read error\n");
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| 			break;
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| 		}
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| 
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| 		err = journal->j_fc_replay_callback(journal, bh, pass,
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| 					next_fc_block - journal->j_fc_first,
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| 					expected_commit_id);
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| 		brelse(bh);
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| 		next_fc_block++;
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| 		if (err < 0 || err == JBD2_FC_REPLAY_STOP)
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| 			break;
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| 		err = 0;
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| 	}
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| 
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| 	if (err)
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| 		jbd2_debug(3, "Fast commit replay failed, err = %d\n", err);
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| 
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| 	return err;
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| }
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| 
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| /**
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|  * jbd2_journal_recover - recovers a on-disk journal
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|  * @journal: the journal to recover
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|  *
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|  * The primary function for recovering the log contents when mounting a
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|  * journaled device.
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|  *
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|  * Recovery is done in three passes.  In the first pass, we look for the
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|  * end of the log.  In the second, we assemble the list of revoke
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|  * blocks.  In the third and final pass, we replay any un-revoked blocks
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|  * in the log.
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|  */
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| int jbd2_journal_recover(journal_t *journal)
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| {
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| 	int			err, err2;
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| 	journal_superblock_t *	sb;
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| 
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| 	struct recovery_info	info;
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| 
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| 	memset(&info, 0, sizeof(info));
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| 	sb = journal->j_superblock;
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| 
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| 	/*
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| 	 * The journal superblock's s_start field (the current log head)
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| 	 * is always zero if, and only if, the journal was cleanly
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| 	 * unmounted.
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| 	 */
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| 	if (!sb->s_start) {
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| 		jbd2_debug(1, "No recovery required, last transaction %d, head block %u\n",
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| 			  be32_to_cpu(sb->s_sequence), be32_to_cpu(sb->s_head));
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| 		journal->j_transaction_sequence = be32_to_cpu(sb->s_sequence) + 1;
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| 		journal->j_head = be32_to_cpu(sb->s_head);
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| 		return 0;
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| 	}
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| 
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| 	err = do_one_pass(journal, &info, PASS_SCAN);
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| 	if (!err)
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| 		err = do_one_pass(journal, &info, PASS_REVOKE);
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| 	if (!err)
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| 		err = do_one_pass(journal, &info, PASS_REPLAY);
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| 
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| 	jbd2_debug(1, "JBD2: recovery, exit status %d, "
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| 		  "recovered transactions %u to %u\n",
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| 		  err, info.start_transaction, info.end_transaction);
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| 	jbd2_debug(1, "JBD2: Replayed %d and revoked %d/%d blocks\n",
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| 		  info.nr_replays, info.nr_revoke_hits, info.nr_revokes);
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| 
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| 	/* Restart the log at the next transaction ID, thus invalidating
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| 	 * any existing commit records in the log. */
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| 	journal->j_transaction_sequence = ++info.end_transaction;
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| 	journal->j_head = info.head_block;
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| 	jbd2_debug(1, "JBD2: last transaction %d, head block %lu\n",
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| 		  journal->j_transaction_sequence, journal->j_head);
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| 
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| 	jbd2_journal_clear_revoke(journal);
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| 	err2 = sync_blockdev(journal->j_fs_dev);
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| 	if (!err)
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| 		err = err2;
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| 	err2 = jbd2_check_fs_dev_write_error(journal);
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| 	if (!err)
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| 		err = err2;
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| 	/* Make sure all replayed data is on permanent storage */
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| 	if (journal->j_flags & JBD2_BARRIER) {
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| 		err2 = blkdev_issue_flush(journal->j_fs_dev);
 | |
| 		if (!err)
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| 			err = err2;
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| 	}
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| 	return err;
 | |
| }
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| 
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| /**
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|  * jbd2_journal_skip_recovery - Start journal and wipe exiting records
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|  * @journal: journal to startup
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|  *
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|  * Locate any valid recovery information from the journal and set up the
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|  * journal structures in memory to ignore it (presumably because the
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|  * caller has evidence that it is out of date).
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|  * This function doesn't appear to be exported..
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|  *
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|  * We perform one pass over the journal to allow us to tell the user how
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|  * much recovery information is being erased, and to let us initialise
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|  * the journal transaction sequence numbers to the next unused ID.
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|  */
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| int jbd2_journal_skip_recovery(journal_t *journal)
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| {
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| 	int			err;
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| 
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| 	struct recovery_info	info;
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| 
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| 	memset (&info, 0, sizeof(info));
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| 
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| 	err = do_one_pass(journal, &info, PASS_SCAN);
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| 
 | |
| 	if (err) {
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| 		printk(KERN_ERR "JBD2: error %d scanning journal\n", err);
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| 		++journal->j_transaction_sequence;
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| 		journal->j_head = journal->j_first;
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| 	} else {
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| #ifdef CONFIG_JBD2_DEBUG
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| 		int dropped = info.end_transaction - 
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| 			be32_to_cpu(journal->j_superblock->s_sequence);
 | |
| 		jbd2_debug(1,
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| 			  "JBD2: ignoring %d transaction%s from the journal.\n",
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| 			  dropped, str_plural(dropped));
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| #endif
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| 		journal->j_transaction_sequence = ++info.end_transaction;
 | |
| 		journal->j_head = info.head_block;
 | |
| 	}
 | |
| 
 | |
| 	journal->j_tail = 0;
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| 	return err;
 | |
| }
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| 
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| static inline unsigned long long read_tag_block(journal_t *journal,
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| 						journal_block_tag_t *tag)
 | |
| {
 | |
| 	unsigned long long block = be32_to_cpu(tag->t_blocknr);
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| 	if (jbd2_has_feature_64bit(journal))
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| 		block |= (u64)be32_to_cpu(tag->t_blocknr_high) << 32;
 | |
| 	return block;
 | |
| }
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| 
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| /*
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|  * calc_chksums calculates the checksums for the blocks described in the
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|  * descriptor block.
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|  */
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| static int calc_chksums(journal_t *journal, struct buffer_head *bh,
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| 			unsigned long *next_log_block, __u32 *crc32_sum)
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| {
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| 	int i, num_blks, err;
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| 	unsigned long io_block;
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| 	struct buffer_head *obh;
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| 
 | |
| 	num_blks = count_tags(journal, bh);
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| 	/* Calculate checksum of the descriptor block. */
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| 	*crc32_sum = crc32_be(*crc32_sum, (void *)bh->b_data, bh->b_size);
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| 
 | |
| 	for (i = 0; i < num_blks; i++) {
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| 		io_block = (*next_log_block)++;
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| 		wrap(journal, *next_log_block);
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| 		err = jread(&obh, journal, io_block);
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| 		if (err) {
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| 			printk(KERN_ERR "JBD2: IO error %d recovering block "
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| 				"%lu in log\n", err, io_block);
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| 			return 1;
 | |
| 		} else {
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| 			*crc32_sum = crc32_be(*crc32_sum, (void *)obh->b_data,
 | |
| 				     obh->b_size);
 | |
| 		}
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| 		put_bh(obh);
 | |
| 	}
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| 	return 0;
 | |
| }
 | |
| 
 | |
| static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
 | |
| {
 | |
| 	struct commit_header *h;
 | |
| 	__be32 provided;
 | |
| 	__u32 calculated;
 | |
| 
 | |
| 	if (!jbd2_journal_has_csum_v2or3(j))
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| 		return 1;
 | |
| 
 | |
| 	h = buf;
 | |
| 	provided = h->h_chksum[0];
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| 	h->h_chksum[0] = 0;
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| 	calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize);
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| 	h->h_chksum[0] = provided;
 | |
| 
 | |
| 	return provided == cpu_to_be32(calculated);
 | |
| }
 | |
| 
 | |
| static bool jbd2_commit_block_csum_verify_partial(journal_t *j, void *buf)
 | |
| {
 | |
| 	struct commit_header *h;
 | |
| 	__be32 provided;
 | |
| 	__u32 calculated;
 | |
| 	void *tmpbuf;
 | |
| 
 | |
| 	tmpbuf = kzalloc(j->j_blocksize, GFP_KERNEL);
 | |
| 	if (!tmpbuf)
 | |
| 		return false;
 | |
| 
 | |
| 	memcpy(tmpbuf, buf, sizeof(struct commit_header));
 | |
| 	h = tmpbuf;
 | |
| 	provided = h->h_chksum[0];
 | |
| 	h->h_chksum[0] = 0;
 | |
| 	calculated = jbd2_chksum(j, j->j_csum_seed, tmpbuf, j->j_blocksize);
 | |
| 	kfree(tmpbuf);
 | |
| 
 | |
| 	return provided == cpu_to_be32(calculated);
 | |
| }
 | |
| 
 | |
| static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag,
 | |
| 				      journal_block_tag3_t *tag3,
 | |
| 				      void *buf, __u32 sequence)
 | |
| {
 | |
| 	__u32 csum32;
 | |
| 	__be32 seq;
 | |
| 
 | |
| 	if (!jbd2_journal_has_csum_v2or3(j))
 | |
| 		return 1;
 | |
| 
 | |
| 	seq = cpu_to_be32(sequence);
 | |
| 	csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
 | |
| 	csum32 = jbd2_chksum(j, csum32, buf, j->j_blocksize);
 | |
| 
 | |
| 	if (jbd2_has_feature_csum3(j))
 | |
| 		return tag3->t_checksum == cpu_to_be32(csum32);
 | |
| 	else
 | |
| 		return tag->t_checksum == cpu_to_be16(csum32);
 | |
| }
 | |
| 
 | |
| static int do_one_pass(journal_t *journal,
 | |
| 			struct recovery_info *info, enum passtype pass)
 | |
| {
 | |
| 	unsigned int		first_commit_ID, next_commit_ID;
 | |
| 	unsigned long		next_log_block, head_block;
 | |
| 	int			err, success = 0;
 | |
| 	journal_superblock_t *	sb;
 | |
| 	journal_header_t *	tmp;
 | |
| 	struct buffer_head *	bh;
 | |
| 	unsigned int		sequence;
 | |
| 	int			blocktype;
 | |
| 	int			tag_bytes = journal_tag_bytes(journal);
 | |
| 	__u32			crc32_sum = ~0; /* Transactional Checksums */
 | |
| 	int			descr_csum_size = 0;
 | |
| 	int			block_error = 0;
 | |
| 	bool			need_check_commit_time = false;
 | |
| 	__u64			last_trans_commit_time = 0, commit_time;
 | |
| 
 | |
| 	/*
 | |
| 	 * First thing is to establish what we expect to find in the log
 | |
| 	 * (in terms of transaction IDs), and where (in terms of log
 | |
| 	 * block offsets): query the superblock.
 | |
| 	 */
 | |
| 
 | |
| 	sb = journal->j_superblock;
 | |
| 	next_commit_ID = be32_to_cpu(sb->s_sequence);
 | |
| 	next_log_block = be32_to_cpu(sb->s_start);
 | |
| 	head_block = next_log_block;
 | |
| 
 | |
| 	first_commit_ID = next_commit_ID;
 | |
| 	if (pass == PASS_SCAN)
 | |
| 		info->start_transaction = first_commit_ID;
 | |
| 
 | |
| 	jbd2_debug(1, "Starting recovery pass %d\n", pass);
 | |
| 
 | |
| 	/*
 | |
| 	 * Now we walk through the log, transaction by transaction,
 | |
| 	 * making sure that each transaction has a commit block in the
 | |
| 	 * expected place.  Each complete transaction gets replayed back
 | |
| 	 * into the main filesystem.
 | |
| 	 */
 | |
| 
 | |
| 	while (1) {
 | |
| 		int			flags;
 | |
| 		char *			tagp;
 | |
| 		journal_block_tag_t	tag;
 | |
| 		struct buffer_head *	obh;
 | |
| 		struct buffer_head *	nbh;
 | |
| 
 | |
| 		cond_resched();
 | |
| 
 | |
| 		/* If we already know where to stop the log traversal,
 | |
| 		 * check right now that we haven't gone past the end of
 | |
| 		 * the log. */
 | |
| 
 | |
| 		if (pass != PASS_SCAN)
 | |
| 			if (tid_geq(next_commit_ID, info->end_transaction))
 | |
| 				break;
 | |
| 
 | |
| 		jbd2_debug(2, "Scanning for sequence ID %u at %lu/%lu\n",
 | |
| 			  next_commit_ID, next_log_block, journal->j_last);
 | |
| 
 | |
| 		/* Skip over each chunk of the transaction looking
 | |
| 		 * either the next descriptor block or the final commit
 | |
| 		 * record. */
 | |
| 
 | |
| 		jbd2_debug(3, "JBD2: checking block %ld\n", next_log_block);
 | |
| 		err = jread(&bh, journal, next_log_block);
 | |
| 		if (err)
 | |
| 			goto failed;
 | |
| 
 | |
| 		next_log_block++;
 | |
| 		wrap(journal, next_log_block);
 | |
| 
 | |
| 		/* What kind of buffer is it?
 | |
| 		 *
 | |
| 		 * If it is a descriptor block, check that it has the
 | |
| 		 * expected sequence number.  Otherwise, we're all done
 | |
| 		 * here. */
 | |
| 
 | |
| 		tmp = (journal_header_t *)bh->b_data;
 | |
| 
 | |
| 		if (tmp->h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER)) {
 | |
| 			brelse(bh);
 | |
| 			break;
 | |
| 		}
 | |
| 
 | |
| 		blocktype = be32_to_cpu(tmp->h_blocktype);
 | |
| 		sequence = be32_to_cpu(tmp->h_sequence);
 | |
| 		jbd2_debug(3, "Found magic %d, sequence %d\n",
 | |
| 			  blocktype, sequence);
 | |
| 
 | |
| 		if (sequence != next_commit_ID) {
 | |
| 			brelse(bh);
 | |
| 			break;
 | |
| 		}
 | |
| 
 | |
| 		/* OK, we have a valid descriptor block which matches
 | |
| 		 * all of the sequence number checks.  What are we going
 | |
| 		 * to do with it?  That depends on the pass... */
 | |
| 
 | |
| 		switch(blocktype) {
 | |
| 		case JBD2_DESCRIPTOR_BLOCK:
 | |
| 			/* Verify checksum first */
 | |
| 			if (jbd2_journal_has_csum_v2or3(journal))
 | |
| 				descr_csum_size =
 | |
| 					sizeof(struct jbd2_journal_block_tail);
 | |
| 			if (descr_csum_size > 0 &&
 | |
| 			    !jbd2_descriptor_block_csum_verify(journal,
 | |
| 							       bh->b_data)) {
 | |
| 				/*
 | |
| 				 * PASS_SCAN can see stale blocks due to lazy
 | |
| 				 * journal init. Don't error out on those yet.
 | |
| 				 */
 | |
| 				if (pass != PASS_SCAN) {
 | |
| 					pr_err("JBD2: Invalid checksum recovering block %lu in log\n",
 | |
| 					       next_log_block);
 | |
| 					err = -EFSBADCRC;
 | |
| 					brelse(bh);
 | |
| 					goto failed;
 | |
| 				}
 | |
| 				need_check_commit_time = true;
 | |
| 				jbd2_debug(1,
 | |
| 					"invalid descriptor block found in %lu\n",
 | |
| 					next_log_block);
 | |
| 			}
 | |
| 
 | |
| 			/* If it is a valid descriptor block, replay it
 | |
| 			 * in pass REPLAY; if journal_checksums enabled, then
 | |
| 			 * calculate checksums in PASS_SCAN, otherwise,
 | |
| 			 * just skip over the blocks it describes. */
 | |
| 			if (pass != PASS_REPLAY) {
 | |
| 				if (pass == PASS_SCAN &&
 | |
| 				    jbd2_has_feature_checksum(journal) &&
 | |
| 				    !need_check_commit_time &&
 | |
| 				    !info->end_transaction) {
 | |
| 					if (calc_chksums(journal, bh,
 | |
| 							&next_log_block,
 | |
| 							&crc32_sum)) {
 | |
| 						put_bh(bh);
 | |
| 						break;
 | |
| 					}
 | |
| 					put_bh(bh);
 | |
| 					continue;
 | |
| 				}
 | |
| 				next_log_block += count_tags(journal, bh);
 | |
| 				wrap(journal, next_log_block);
 | |
| 				put_bh(bh);
 | |
| 				continue;
 | |
| 			}
 | |
| 
 | |
| 			/* A descriptor block: we can now write all of
 | |
| 			 * the data blocks.  Yay, useful work is finally
 | |
| 			 * getting done here! */
 | |
| 
 | |
| 			tagp = &bh->b_data[sizeof(journal_header_t)];
 | |
| 			while ((tagp - bh->b_data + tag_bytes)
 | |
| 			       <= journal->j_blocksize - descr_csum_size) {
 | |
| 				unsigned long io_block;
 | |
| 
 | |
| 				memcpy(&tag, tagp, sizeof(tag));
 | |
| 				flags = be16_to_cpu(tag.t_flags);
 | |
| 
 | |
| 				io_block = next_log_block++;
 | |
| 				wrap(journal, next_log_block);
 | |
| 				err = jread(&obh, journal, io_block);
 | |
| 				if (err) {
 | |
| 					/* Recover what we can, but
 | |
| 					 * report failure at the end. */
 | |
| 					success = err;
 | |
| 					printk(KERN_ERR
 | |
| 						"JBD2: IO error %d recovering "
 | |
| 						"block %lu in log\n",
 | |
| 						err, io_block);
 | |
| 				} else {
 | |
| 					unsigned long long blocknr;
 | |
| 
 | |
| 					J_ASSERT(obh != NULL);
 | |
| 					blocknr = read_tag_block(journal,
 | |
| 								 &tag);
 | |
| 
 | |
| 					/* If the block has been
 | |
| 					 * revoked, then we're all done
 | |
| 					 * here. */
 | |
| 					if (jbd2_journal_test_revoke
 | |
| 					    (journal, blocknr,
 | |
| 					     next_commit_ID)) {
 | |
| 						brelse(obh);
 | |
| 						++info->nr_revoke_hits;
 | |
| 						goto skip_write;
 | |
| 					}
 | |
| 
 | |
| 					/* Look for block corruption */
 | |
| 					if (!jbd2_block_tag_csum_verify(
 | |
| 			journal, &tag, (journal_block_tag3_t *)tagp,
 | |
| 			obh->b_data, be32_to_cpu(tmp->h_sequence))) {
 | |
| 						brelse(obh);
 | |
| 						success = -EFSBADCRC;
 | |
| 						printk(KERN_ERR "JBD2: Invalid "
 | |
| 						       "checksum recovering "
 | |
| 						       "data block %llu in "
 | |
| 						       "journal block %lu\n",
 | |
| 						       blocknr, io_block);
 | |
| 						block_error = 1;
 | |
| 						goto skip_write;
 | |
| 					}
 | |
| 
 | |
| 					/* Find a buffer for the new
 | |
| 					 * data being restored */
 | |
| 					nbh = __getblk(journal->j_fs_dev,
 | |
| 							blocknr,
 | |
| 							journal->j_blocksize);
 | |
| 					if (nbh == NULL) {
 | |
| 						printk(KERN_ERR
 | |
| 						       "JBD2: Out of memory "
 | |
| 						       "during recovery.\n");
 | |
| 						err = -ENOMEM;
 | |
| 						brelse(bh);
 | |
| 						brelse(obh);
 | |
| 						goto failed;
 | |
| 					}
 | |
| 
 | |
| 					lock_buffer(nbh);
 | |
| 					memcpy(nbh->b_data, obh->b_data,
 | |
| 							journal->j_blocksize);
 | |
| 					if (flags & JBD2_FLAG_ESCAPE) {
 | |
| 						*((__be32 *)nbh->b_data) =
 | |
| 						cpu_to_be32(JBD2_MAGIC_NUMBER);
 | |
| 					}
 | |
| 
 | |
| 					BUFFER_TRACE(nbh, "marking dirty");
 | |
| 					set_buffer_uptodate(nbh);
 | |
| 					mark_buffer_dirty(nbh);
 | |
| 					BUFFER_TRACE(nbh, "marking uptodate");
 | |
| 					++info->nr_replays;
 | |
| 					unlock_buffer(nbh);
 | |
| 					brelse(obh);
 | |
| 					brelse(nbh);
 | |
| 				}
 | |
| 
 | |
| 			skip_write:
 | |
| 				tagp += tag_bytes;
 | |
| 				if (!(flags & JBD2_FLAG_SAME_UUID))
 | |
| 					tagp += 16;
 | |
| 
 | |
| 				if (flags & JBD2_FLAG_LAST_TAG)
 | |
| 					break;
 | |
| 			}
 | |
| 
 | |
| 			brelse(bh);
 | |
| 			continue;
 | |
| 
 | |
| 		case JBD2_COMMIT_BLOCK:
 | |
| 			/*     How to differentiate between interrupted commit
 | |
| 			 *               and journal corruption ?
 | |
| 			 *
 | |
| 			 * {nth transaction}
 | |
| 			 *        Checksum Verification Failed
 | |
| 			 *			 |
 | |
| 			 *		 ____________________
 | |
| 			 *		|		     |
 | |
| 			 * 	async_commit             sync_commit
 | |
| 			 *     		|                    |
 | |
| 			 *		| GO TO NEXT    "Journal Corruption"
 | |
| 			 *		| TRANSACTION
 | |
| 			 *		|
 | |
| 			 * {(n+1)th transanction}
 | |
| 			 *		|
 | |
| 			 * 	 _______|______________
 | |
| 			 * 	|	 	      |
 | |
| 			 * Commit block found	Commit block not found
 | |
| 			 *      |		      |
 | |
| 			 * "Journal Corruption"       |
 | |
| 			 *		 _____________|_________
 | |
| 			 *     		|	           	|
 | |
| 			 *	nth trans corrupt	OR   nth trans
 | |
| 			 *	and (n+1)th interrupted     interrupted
 | |
| 			 *	before commit block
 | |
| 			 *      could reach the disk.
 | |
| 			 *	(Cannot find the difference in above
 | |
| 			 *	 mentioned conditions. Hence assume
 | |
| 			 *	 "Interrupted Commit".)
 | |
| 			 */
 | |
| 			commit_time = be64_to_cpu(
 | |
| 				((struct commit_header *)bh->b_data)->h_commit_sec);
 | |
| 			/*
 | |
| 			 * If need_check_commit_time is set, it means we are in
 | |
| 			 * PASS_SCAN and csum verify failed before. If
 | |
| 			 * commit_time is increasing, it's the same journal,
 | |
| 			 * otherwise it is stale journal block, just end this
 | |
| 			 * recovery.
 | |
| 			 */
 | |
| 			if (need_check_commit_time) {
 | |
| 				if (commit_time >= last_trans_commit_time) {
 | |
| 					pr_err("JBD2: Invalid checksum found in transaction %u\n",
 | |
| 					       next_commit_ID);
 | |
| 					err = -EFSBADCRC;
 | |
| 					brelse(bh);
 | |
| 					goto failed;
 | |
| 				}
 | |
| 			ignore_crc_mismatch:
 | |
| 				/*
 | |
| 				 * It likely does not belong to same journal,
 | |
| 				 * just end this recovery with success.
 | |
| 				 */
 | |
| 				jbd2_debug(1, "JBD2: Invalid checksum ignored in transaction %u, likely stale data\n",
 | |
| 					  next_commit_ID);
 | |
| 				brelse(bh);
 | |
| 				goto done;
 | |
| 			}
 | |
| 
 | |
| 			/*
 | |
| 			 * Found an expected commit block: if checksums
 | |
| 			 * are present, verify them in PASS_SCAN; else not
 | |
| 			 * much to do other than move on to the next sequence
 | |
| 			 * number.
 | |
| 			 */
 | |
| 			if (pass == PASS_SCAN &&
 | |
| 			    jbd2_has_feature_checksum(journal)) {
 | |
| 				struct commit_header *cbh =
 | |
| 					(struct commit_header *)bh->b_data;
 | |
| 				unsigned found_chksum =
 | |
| 					be32_to_cpu(cbh->h_chksum[0]);
 | |
| 
 | |
| 				if (info->end_transaction) {
 | |
| 					journal->j_failed_commit =
 | |
| 						info->end_transaction;
 | |
| 					brelse(bh);
 | |
| 					break;
 | |
| 				}
 | |
| 
 | |
| 				/* Neither checksum match nor unused? */
 | |
| 				if (!((crc32_sum == found_chksum &&
 | |
| 				       cbh->h_chksum_type ==
 | |
| 						JBD2_CRC32_CHKSUM &&
 | |
| 				       cbh->h_chksum_size ==
 | |
| 						JBD2_CRC32_CHKSUM_SIZE) ||
 | |
| 				      (cbh->h_chksum_type == 0 &&
 | |
| 				       cbh->h_chksum_size == 0 &&
 | |
| 				       found_chksum == 0)))
 | |
| 					goto chksum_error;
 | |
| 
 | |
| 				crc32_sum = ~0;
 | |
| 			}
 | |
| 			if (pass == PASS_SCAN &&
 | |
| 			    !jbd2_commit_block_csum_verify(journal,
 | |
| 							   bh->b_data)) {
 | |
| 				if (jbd2_commit_block_csum_verify_partial(
 | |
| 								  journal,
 | |
| 								  bh->b_data)) {
 | |
| 					pr_notice("JBD2: Find incomplete commit block in transaction %u block %lu\n",
 | |
| 						  next_commit_ID, next_log_block);
 | |
| 					goto chksum_ok;
 | |
| 				}
 | |
| 			chksum_error:
 | |
| 				if (commit_time < last_trans_commit_time)
 | |
| 					goto ignore_crc_mismatch;
 | |
| 				info->end_transaction = next_commit_ID;
 | |
| 				info->head_block = head_block;
 | |
| 
 | |
| 				if (!jbd2_has_feature_async_commit(journal)) {
 | |
| 					journal->j_failed_commit =
 | |
| 						next_commit_ID;
 | |
| 					brelse(bh);
 | |
| 					break;
 | |
| 				}
 | |
| 			}
 | |
| 			if (pass == PASS_SCAN) {
 | |
| 			chksum_ok:
 | |
| 				last_trans_commit_time = commit_time;
 | |
| 				head_block = next_log_block;
 | |
| 			}
 | |
| 			brelse(bh);
 | |
| 			next_commit_ID++;
 | |
| 			continue;
 | |
| 
 | |
| 		case JBD2_REVOKE_BLOCK:
 | |
| 			/*
 | |
| 			 * Check revoke block crc in pass_scan, if csum verify
 | |
| 			 * failed, check commit block time later.
 | |
| 			 */
 | |
| 			if (pass == PASS_SCAN &&
 | |
| 			    !jbd2_descriptor_block_csum_verify(journal,
 | |
| 							       bh->b_data)) {
 | |
| 				jbd2_debug(1, "JBD2: invalid revoke block found in %lu\n",
 | |
| 					  next_log_block);
 | |
| 				need_check_commit_time = true;
 | |
| 			}
 | |
| 
 | |
| 			/* If we aren't in the REVOKE pass, then we can
 | |
| 			 * just skip over this block. */
 | |
| 			if (pass != PASS_REVOKE) {
 | |
| 				brelse(bh);
 | |
| 				continue;
 | |
| 			}
 | |
| 
 | |
| 			err = scan_revoke_records(journal, bh,
 | |
| 						  next_commit_ID, info);
 | |
| 			brelse(bh);
 | |
| 			if (err)
 | |
| 				goto failed;
 | |
| 			continue;
 | |
| 
 | |
| 		default:
 | |
| 			jbd2_debug(3, "Unrecognised magic %d, end of scan.\n",
 | |
| 				  blocktype);
 | |
| 			brelse(bh);
 | |
| 			goto done;
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
|  done:
 | |
| 	/*
 | |
| 	 * We broke out of the log scan loop: either we came to the
 | |
| 	 * known end of the log or we found an unexpected block in the
 | |
| 	 * log.  If the latter happened, then we know that the "current"
 | |
| 	 * transaction marks the end of the valid log.
 | |
| 	 */
 | |
| 
 | |
| 	if (pass == PASS_SCAN) {
 | |
| 		if (!info->end_transaction)
 | |
| 			info->end_transaction = next_commit_ID;
 | |
| 		if (!info->head_block)
 | |
| 			info->head_block = head_block;
 | |
| 	} else {
 | |
| 		/* It's really bad news if different passes end up at
 | |
| 		 * different places (but possible due to IO errors). */
 | |
| 		if (info->end_transaction != next_commit_ID) {
 | |
| 			printk(KERN_ERR "JBD2: recovery pass %d ended at "
 | |
| 				"transaction %u, expected %u\n",
 | |
| 				pass, next_commit_ID, info->end_transaction);
 | |
| 			if (!success)
 | |
| 				success = -EIO;
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| 	if (jbd2_has_feature_fast_commit(journal) &&  pass != PASS_REVOKE) {
 | |
| 		err = fc_do_one_pass(journal, info, pass);
 | |
| 		if (err)
 | |
| 			success = err;
 | |
| 	}
 | |
| 
 | |
| 	if (block_error && success == 0)
 | |
| 		success = -EIO;
 | |
| 	return success;
 | |
| 
 | |
|  failed:
 | |
| 	return err;
 | |
| }
 | |
| 
 | |
| /* Scan a revoke record, marking all blocks mentioned as revoked. */
 | |
| 
 | |
| static int scan_revoke_records(journal_t *journal, struct buffer_head *bh,
 | |
| 			       tid_t sequence, struct recovery_info *info)
 | |
| {
 | |
| 	jbd2_journal_revoke_header_t *header;
 | |
| 	int offset, max;
 | |
| 	unsigned csum_size = 0;
 | |
| 	__u32 rcount;
 | |
| 	int record_len = 4;
 | |
| 
 | |
| 	header = (jbd2_journal_revoke_header_t *) bh->b_data;
 | |
| 	offset = sizeof(jbd2_journal_revoke_header_t);
 | |
| 	rcount = be32_to_cpu(header->r_count);
 | |
| 
 | |
| 	if (jbd2_journal_has_csum_v2or3(journal))
 | |
| 		csum_size = sizeof(struct jbd2_journal_block_tail);
 | |
| 	if (rcount > journal->j_blocksize - csum_size)
 | |
| 		return -EINVAL;
 | |
| 	max = rcount;
 | |
| 
 | |
| 	if (jbd2_has_feature_64bit(journal))
 | |
| 		record_len = 8;
 | |
| 
 | |
| 	while (offset + record_len <= max) {
 | |
| 		unsigned long long blocknr;
 | |
| 		int err;
 | |
| 
 | |
| 		if (record_len == 4)
 | |
| 			blocknr = be32_to_cpu(* ((__be32 *) (bh->b_data+offset)));
 | |
| 		else
 | |
| 			blocknr = be64_to_cpu(* ((__be64 *) (bh->b_data+offset)));
 | |
| 		offset += record_len;
 | |
| 		err = jbd2_journal_set_revoke(journal, blocknr, sequence);
 | |
| 		if (err)
 | |
| 			return err;
 | |
| 		++info->nr_revokes;
 | |
| 	}
 | |
| 	return 0;
 | |
| }
 |