[v3] ocfs2: call journal flush to mark journal as empty after journal recovery when mount
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Message ID 20191217020140.2197-1-li.kai4@h3c.com
State New
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Series
  • [v3] ocfs2: call journal flush to mark journal as empty after journal recovery when mount
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Commit Message

Likai Dec. 17, 2019, 2:01 a.m. UTC
If journal is dirty when mount, it will be replayed but jbd2 sb
log tail cannot be updated to mark a new start because
journal->j_flag has already been set with JBD2_ABORT first
in journal_init_common. When a new transaction is committed, it
will be recored in block 1 first(journal->j_tail is set to 1 in
journal_reset).If emergency restart happens again before journal
super block is updated unfortunately, the new recorded trans will
not be replayed in the next mount.

The following steps describe this procedure in detail.
1. mount and touch some files
2. these transactions are committed to journal area but not checkpointed
3. emergency restart
4. mount again and its journals are replayed
5. journal super block's first s_start is 1, but its s_seq is not updated
6. touch a new file and its trans is committed but not checkpointed
7. emergency restart again
8. mount and journal is dirty, but trans committed in 6 will not be
replayed.

This exception happens easily when this lun is used by only one node. If it
is used by multi-nodes, other node will replay its journal and its
journal super block will be updated after recovery like what this patch
does.

ocfs2_recover_node->ocfs2_replay_journal.

The following jbd2 journal can be generated by touching a new file after
journal is replayed, and seq 15 is the first valid commit, but first seq
is 13 in journal super block.
logdump:
Block 0: Journal Superblock
Seq: 0   Type: 4 (JBD2_SUPERBLOCK_V2)
Blocksize: 4096   Total Blocks: 32768   First Block: 1
First Commit ID: 13   Start Log Blknum: 1
Error: 0
Feature Compat: 0
Feature Incompat: 2 block64
Feature RO compat: 0
Journal UUID: 4ED3822C54294467A4F8E87D2BA4BC36
FS Share Cnt: 1   Dynamic Superblk Blknum: 0
Per Txn Block Limit    Journal: 0    Data: 0

Block 1: Journal Commit Block
Seq: 14   Type: 2 (JBD2_COMMIT_BLOCK)

Block 2: Journal Descriptor
Seq: 15   Type: 1 (JBD2_DESCRIPTOR_BLOCK)
No. Blocknum        Flags
 0. 587             none
UUID: 00000000000000000000000000000000
 1. 8257792         JBD2_FLAG_SAME_UUID
 2. 619             JBD2_FLAG_SAME_UUID
 3. 24772864        JBD2_FLAG_SAME_UUID
 4. 8257802         JBD2_FLAG_SAME_UUID
 5. 513             JBD2_FLAG_SAME_UUID JBD2_FLAG_LAST_TAG
...
Block 7: Inode
Inode: 8257802   Mode: 0640   Generation: 57157641 (0x3682809)
FS Generation: 2839773110 (0xa9437fb6)
CRC32: 00000000   ECC: 0000
Type: Regular   Attr: 0x0   Flags: Valid
Dynamic Features: (0x1) InlineData
User: 0 (root)   Group: 0 (root)   Size: 7
Links: 1   Clusters: 0
ctime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
atime: 0x5de5d870 0x113181a1 -- Tue Dec  3 11:37:20.288457121 2019
mtime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
dtime: 0x0 -- Thu Jan  1 08:00:00 1970
...
Block 9: Journal Commit Block
Seq: 15   Type: 2 (JBD2_COMMIT_BLOCK)

The following is jouranl recovery log when recovering the upper jbd2
journal when mount again.
syslog:
[ 2265.648622] ocfs2: File system on device (252,1) was not unmounted cleanly, recovering it.
[ 2265.649695] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 0
[ 2265.650407] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 1
[ 2265.650409] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 2
[ 2265.650410] fs/jbd2/recovery.c:(jbd2_journal_recover, 278): JBD2: recovery, exit status 0, recovered transactions 13 to 13

Due to first commit seq 13 recorded in journal super is not consistent
with the value recorded in block 1(seq is 14), journal recovery will be
terminated before seq 15 even though it is an unbroken commit, inode
8257802 is a new file and it will be lost.

Signed-off-by: Kai Li <li.kai4@h3c.com>
---
 fs/ocfs2/journal.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Comments

Joseph Qi Dec. 17, 2019, 2:12 a.m. UTC | #1
On 19/12/17 10:01, Kai Li wrote:
> If journal is dirty when mount, it will be replayed but jbd2 sb
> log tail cannot be updated to mark a new start because
> journal->j_flag has already been set with JBD2_ABORT first
> in journal_init_common. When a new transaction is committed, it
> will be recored in block 1 first(journal->j_tail is set to 1 in
> journal_reset).If emergency restart happens again before journal
> super block is updated unfortunately, the new recorded trans will
> not be replayed in the next mount.
> 
> The following steps describe this procedure in detail.
> 1. mount and touch some files
> 2. these transactions are committed to journal area but not checkpointed
> 3. emergency restart
> 4. mount again and its journals are replayed
> 5. journal super block's first s_start is 1, but its s_seq is not updated
> 6. touch a new file and its trans is committed but not checkpointed
> 7. emergency restart again
> 8. mount and journal is dirty, but trans committed in 6 will not be
> replayed.
> 
> This exception happens easily when this lun is used by only one node. If it
> is used by multi-nodes, other node will replay its journal and its
> journal super block will be updated after recovery like what this patch
> does.
> 
> ocfs2_recover_node->ocfs2_replay_journal.
> 
> The following jbd2 journal can be generated by touching a new file after
> journal is replayed, and seq 15 is the first valid commit, but first seq
> is 13 in journal super block.
> logdump:
> Block 0: Journal Superblock
> Seq: 0   Type: 4 (JBD2_SUPERBLOCK_V2)
> Blocksize: 4096   Total Blocks: 32768   First Block: 1
> First Commit ID: 13   Start Log Blknum: 1
> Error: 0
> Feature Compat: 0
> Feature Incompat: 2 block64
> Feature RO compat: 0
> Journal UUID: 4ED3822C54294467A4F8E87D2BA4BC36
> FS Share Cnt: 1   Dynamic Superblk Blknum: 0
> Per Txn Block Limit    Journal: 0    Data: 0
> 
> Block 1: Journal Commit Block
> Seq: 14   Type: 2 (JBD2_COMMIT_BLOCK)
> 
> Block 2: Journal Descriptor
> Seq: 15   Type: 1 (JBD2_DESCRIPTOR_BLOCK)
> No. Blocknum        Flags
>  0. 587             none
> UUID: 00000000000000000000000000000000
>  1. 8257792         JBD2_FLAG_SAME_UUID
>  2. 619             JBD2_FLAG_SAME_UUID
>  3. 24772864        JBD2_FLAG_SAME_UUID
>  4. 8257802         JBD2_FLAG_SAME_UUID
>  5. 513             JBD2_FLAG_SAME_UUID JBD2_FLAG_LAST_TAG
> ...
> Block 7: Inode
> Inode: 8257802   Mode: 0640   Generation: 57157641 (0x3682809)
> FS Generation: 2839773110 (0xa9437fb6)
> CRC32: 00000000   ECC: 0000
> Type: Regular   Attr: 0x0   Flags: Valid
> Dynamic Features: (0x1) InlineData
> User: 0 (root)   Group: 0 (root)   Size: 7
> Links: 1   Clusters: 0
> ctime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
> atime: 0x5de5d870 0x113181a1 -- Tue Dec  3 11:37:20.288457121 2019
> mtime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
> dtime: 0x0 -- Thu Jan  1 08:00:00 1970
> ...
> Block 9: Journal Commit Block
> Seq: 15   Type: 2 (JBD2_COMMIT_BLOCK)
> 
> The following is jouranl recovery log when recovering the upper jbd2
> journal when mount again.
> syslog:
> [ 2265.648622] ocfs2: File system on device (252,1) was not unmounted cleanly, recovering it.
> [ 2265.649695] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 0
> [ 2265.650407] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 1
> [ 2265.650409] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 2
> [ 2265.650410] fs/jbd2/recovery.c:(jbd2_journal_recover, 278): JBD2: recovery, exit status 0, recovered transactions 13 to 13
> 
> Due to first commit seq 13 recorded in journal super is not consistent
> with the value recorded in block 1(seq is 14), journal recovery will be
> terminated before seq 15 even though it is an unbroken commit, inode
> 8257802 is a new file and it will be lost.
> 
> Signed-off-by: Kai Li <li.kai4@h3c.com>

Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
> ---
>  fs/ocfs2/journal.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
> index 1afe57f425a0..68ba354cf361 100644
> --- a/fs/ocfs2/journal.c
> +++ b/fs/ocfs2/journal.c
> @@ -1066,6 +1066,14 @@ int ocfs2_journal_load(struct ocfs2_journal *journal, int local, int replayed)
>  
>  	ocfs2_clear_journal_error(osb->sb, journal->j_journal, osb->slot_num);
>  
> +	if (replayed) {
> +		jbd2_journal_lock_updates(journal->j_journal);
> +		status = jbd2_journal_flush(journal->j_journal);
> +		jbd2_journal_unlock_updates(journal->j_journal);
> +		if (status < 0)
> +			mlog_errno(status);
> +	}
> +
>  	status = ocfs2_journal_toggle_dirty(osb, 1, replayed);
>  	if (status < 0) {
>  		mlog_errno(status);
>
Changwei Ge Dec. 17, 2019, 2:42 a.m. UTC | #2
Reviewed-by: Changwei Ge <gechangwei@live.cn>

On 12/17/19 10:01 AM, Kai Li wrote:
> If journal is dirty when mount, it will be replayed but jbd2 sb
> log tail cannot be updated to mark a new start because
> journal->j_flag has already been set with JBD2_ABORT first
> in journal_init_common. When a new transaction is committed, it
> will be recored in block 1 first(journal->j_tail is set to 1 in
> journal_reset).If emergency restart happens again before journal
> super block is updated unfortunately, the new recorded trans will
> not be replayed in the next mount.
> 
> The following steps describe this procedure in detail.
> 1. mount and touch some files
> 2. these transactions are committed to journal area but not checkpointed
> 3. emergency restart
> 4. mount again and its journals are replayed
> 5. journal super block's first s_start is 1, but its s_seq is not updated
> 6. touch a new file and its trans is committed but not checkpointed
> 7. emergency restart again
> 8. mount and journal is dirty, but trans committed in 6 will not be
> replayed.
> 
> This exception happens easily when this lun is used by only one node. If it
> is used by multi-nodes, other node will replay its journal and its
> journal super block will be updated after recovery like what this patch
> does.
> 
> ocfs2_recover_node->ocfs2_replay_journal.
> 
> The following jbd2 journal can be generated by touching a new file after
> journal is replayed, and seq 15 is the first valid commit, but first seq
> is 13 in journal super block.
> logdump:
> Block 0: Journal Superblock
> Seq: 0   Type: 4 (JBD2_SUPERBLOCK_V2)
> Blocksize: 4096   Total Blocks: 32768   First Block: 1
> First Commit ID: 13   Start Log Blknum: 1
> Error: 0
> Feature Compat: 0
> Feature Incompat: 2 block64
> Feature RO compat: 0
> Journal UUID: 4ED3822C54294467A4F8E87D2BA4BC36
> FS Share Cnt: 1   Dynamic Superblk Blknum: 0
> Per Txn Block Limit    Journal: 0    Data: 0
> 
> Block 1: Journal Commit Block
> Seq: 14   Type: 2 (JBD2_COMMIT_BLOCK)
> 
> Block 2: Journal Descriptor
> Seq: 15   Type: 1 (JBD2_DESCRIPTOR_BLOCK)
> No. Blocknum        Flags
>   0. 587             none
> UUID: 00000000000000000000000000000000
>   1. 8257792         JBD2_FLAG_SAME_UUID
>   2. 619             JBD2_FLAG_SAME_UUID
>   3. 24772864        JBD2_FLAG_SAME_UUID
>   4. 8257802         JBD2_FLAG_SAME_UUID
>   5. 513             JBD2_FLAG_SAME_UUID JBD2_FLAG_LAST_TAG
> ...
> Block 7: Inode
> Inode: 8257802   Mode: 0640   Generation: 57157641 (0x3682809)
> FS Generation: 2839773110 (0xa9437fb6)
> CRC32: 00000000   ECC: 0000
> Type: Regular   Attr: 0x0   Flags: Valid
> Dynamic Features: (0x1) InlineData
> User: 0 (root)   Group: 0 (root)   Size: 7
> Links: 1   Clusters: 0
> ctime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
> atime: 0x5de5d870 0x113181a1 -- Tue Dec  3 11:37:20.288457121 2019
> mtime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
> dtime: 0x0 -- Thu Jan  1 08:00:00 1970
> ...
> Block 9: Journal Commit Block
> Seq: 15   Type: 2 (JBD2_COMMIT_BLOCK)
> 
> The following is jouranl recovery log when recovering the upper jbd2
> journal when mount again.
> syslog:
> [ 2265.648622] ocfs2: File system on device (252,1) was not unmounted cleanly, recovering it.
> [ 2265.649695] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 0
> [ 2265.650407] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 1
> [ 2265.650409] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 2
> [ 2265.650410] fs/jbd2/recovery.c:(jbd2_journal_recover, 278): JBD2: recovery, exit status 0, recovered transactions 13 to 13
> 
> Due to first commit seq 13 recorded in journal super is not consistent
> with the value recorded in block 1(seq is 14), journal recovery will be
> terminated before seq 15 even though it is an unbroken commit, inode
> 8257802 is a new file and it will be lost.
> 
> Signed-off-by: Kai Li <li.kai4@h3c.com>
> ---
>   fs/ocfs2/journal.c | 8 ++++++++
>   1 file changed, 8 insertions(+)
> 
> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
> index 1afe57f425a0..68ba354cf361 100644
> --- a/fs/ocfs2/journal.c
> +++ b/fs/ocfs2/journal.c
> @@ -1066,6 +1066,14 @@ int ocfs2_journal_load(struct ocfs2_journal *journal, int local, int replayed)
>   
>   	ocfs2_clear_journal_error(osb->sb, journal->j_journal, osb->slot_num);
>   
> +	if (replayed) {
> +		jbd2_journal_lock_updates(journal->j_journal);
> +		status = jbd2_journal_flush(journal->j_journal);
> +		jbd2_journal_unlock_updates(journal->j_journal);
> +		if (status < 0)
> +			mlog_errno(status);
> +	}
> +
>   	status = ocfs2_journal_toggle_dirty(osb, 1, replayed);
>   	if (status < 0) {
>   		mlog_errno(status);
>
Andrew Morton Dec. 18, 2019, 2:23 a.m. UTC | #3
On Tue, 17 Dec 2019 10:12:14 +0800 Joseph Qi <jiangqi903@gmail.com> wrote:

> > Due to first commit seq 13 recorded in journal super is not consistent
> > with the value recorded in block 1(seq is 14), journal recovery will be
> > terminated before seq 15 even though it is an unbroken commit, inode
> > 8257802 is a new file and it will be lost.
> > 
> > Signed-off-by: Kai Li <li.kai4@h3c.com>
> 
> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>

Do we think this fix should be backported into -stable kernels?
Joseph Qi Dec. 18, 2019, 4:56 a.m. UTC | #4
On 19/12/18 10:23, Andrew Morton wrote:
> On Tue, 17 Dec 2019 10:12:14 +0800 Joseph Qi <jiangqi903@gmail.com> wrote:
> 
>>> Due to first commit seq 13 recorded in journal super is not consistent
>>> with the value recorded in block 1(seq is 14), journal recovery will be
>>> terminated before seq 15 even though it is an unbroken commit, inode
>>> 8257802 is a new file and it will be lost.
>>>
>>> Signed-off-by: Kai Li <li.kai4@h3c.com>
>>
>> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
> 
> Do we think this fix should be backported into -stable kernels?
> 
Since this is not an usual usecase, we don't have to.
It is enough to let it go into upstream.

Thanks,
Joseph
piaojun Dec. 19, 2019, 2:15 p.m. UTC | #5
On 2019/12/17 10:01, Kai Li wrote:
> If journal is dirty when mount, it will be replayed but jbd2 sb
> log tail cannot be updated to mark a new start because
> journal->j_flag has already been set with JBD2_ABORT first
> in journal_init_common. When a new transaction is committed, it
> will be recored in block 1 first(journal->j_tail is set to 1 in
> journal_reset).If emergency restart happens again before journal
> super block is updated unfortunately, the new recorded trans will
> not be replayed in the next mount.
> 
> The following steps describe this procedure in detail.
> 1. mount and touch some files
> 2. these transactions are committed to journal area but not checkpointed
> 3. emergency restart
> 4. mount again and its journals are replayed
> 5. journal super block's first s_start is 1, but its s_seq is not updated
> 6. touch a new file and its trans is committed but not checkpointed
> 7. emergency restart again
> 8. mount and journal is dirty, but trans committed in 6 will not be
> replayed.
> 
> This exception happens easily when this lun is used by only one node. If it
> is used by multi-nodes, other node will replay its journal and its
> journal super block will be updated after recovery like what this patch
> does.
> 
> ocfs2_recover_node->ocfs2_replay_journal.
> 
> The following jbd2 journal can be generated by touching a new file after
> journal is replayed, and seq 15 is the first valid commit, but first seq
> is 13 in journal super block.
> logdump:
> Block 0: Journal Superblock
> Seq: 0   Type: 4 (JBD2_SUPERBLOCK_V2)
> Blocksize: 4096   Total Blocks: 32768   First Block: 1
> First Commit ID: 13   Start Log Blknum: 1
> Error: 0
> Feature Compat: 0
> Feature Incompat: 2 block64
> Feature RO compat: 0
> Journal UUID: 4ED3822C54294467A4F8E87D2BA4BC36
> FS Share Cnt: 1   Dynamic Superblk Blknum: 0
> Per Txn Block Limit    Journal: 0    Data: 0
> 
> Block 1: Journal Commit Block
> Seq: 14   Type: 2 (JBD2_COMMIT_BLOCK)
> 
> Block 2: Journal Descriptor
> Seq: 15   Type: 1 (JBD2_DESCRIPTOR_BLOCK)
> No. Blocknum        Flags
>  0. 587             none
> UUID: 00000000000000000000000000000000
>  1. 8257792         JBD2_FLAG_SAME_UUID
>  2. 619             JBD2_FLAG_SAME_UUID
>  3. 24772864        JBD2_FLAG_SAME_UUID
>  4. 8257802         JBD2_FLAG_SAME_UUID
>  5. 513             JBD2_FLAG_SAME_UUID JBD2_FLAG_LAST_TAG
> ...
> Block 7: Inode
> Inode: 8257802   Mode: 0640   Generation: 57157641 (0x3682809)
> FS Generation: 2839773110 (0xa9437fb6)
> CRC32: 00000000   ECC: 0000
> Type: Regular   Attr: 0x0   Flags: Valid
> Dynamic Features: (0x1) InlineData
> User: 0 (root)   Group: 0 (root)   Size: 7
> Links: 1   Clusters: 0
> ctime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
> atime: 0x5de5d870 0x113181a1 -- Tue Dec  3 11:37:20.288457121 2019
> mtime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
> dtime: 0x0 -- Thu Jan  1 08:00:00 1970
> ...
> Block 9: Journal Commit Block
> Seq: 15   Type: 2 (JBD2_COMMIT_BLOCK)
> 
> The following is jouranl recovery log when recovering the upper jbd2
> journal when mount again.
> syslog:
> [ 2265.648622] ocfs2: File system on device (252,1) was not unmounted cleanly, recovering it.
> [ 2265.649695] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 0
> [ 2265.650407] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 1
> [ 2265.650409] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 2
> [ 2265.650410] fs/jbd2/recovery.c:(jbd2_journal_recover, 278): JBD2: recovery, exit status 0, recovered transactions 13 to 13
> 
> Due to first commit seq 13 recorded in journal super is not consistent
> with the value recorded in block 1(seq is 14), journal recovery will be
> terminated before seq 15 even though it is an unbroken commit, inode
> 8257802 is a new file and it will be lost.
> 
> Signed-off-by: Kai Li <li.kai4@h3c.com>
> ---
>  fs/ocfs2/journal.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
> index 1afe57f425a0..68ba354cf361 100644
> --- a/fs/ocfs2/journal.c
> +++ b/fs/ocfs2/journal.c
> @@ -1066,6 +1066,14 @@ int ocfs2_journal_load(struct ocfs2_journal *journal, int local, int replayed)
>  
>  	ocfs2_clear_journal_error(osb->sb, journal->j_journal, osb->slot_num);
>  
> +	if (replayed) {
> +		jbd2_journal_lock_updates(journal->j_journal);
> +		status = jbd2_journal_flush(journal->j_journal);

What if jbd2_journal_flush gets failed? The 's_sequence' and 's_start'
won't be reset, and I wonder if the problem still remains.

Thanks,
Jun

> +		jbd2_journal_unlock_updates(journal->j_journal);
> +		if (status < 0)
> +			mlog_errno(status);
> +	}
> +
>  	status = ocfs2_journal_toggle_dirty(osb, 1, replayed);
>  	if (status < 0) {
>  		mlog_errno(status);
>
Joseph Qi Dec. 20, 2019, 1:11 a.m. UTC | #6
On 19/12/19 22:15, piaojun wrote:
> 
> 
> On 2019/12/17 10:01, Kai Li wrote:
>> If journal is dirty when mount, it will be replayed but jbd2 sb
>> log tail cannot be updated to mark a new start because
>> journal->j_flag has already been set with JBD2_ABORT first
>> in journal_init_common. When a new transaction is committed, it
>> will be recored in block 1 first(journal->j_tail is set to 1 in
>> journal_reset).If emergency restart happens again before journal
>> super block is updated unfortunately, the new recorded trans will
>> not be replayed in the next mount.
>>
>> The following steps describe this procedure in detail.
>> 1. mount and touch some files
>> 2. these transactions are committed to journal area but not checkpointed
>> 3. emergency restart
>> 4. mount again and its journals are replayed
>> 5. journal super block's first s_start is 1, but its s_seq is not updated
>> 6. touch a new file and its trans is committed but not checkpointed
>> 7. emergency restart again
>> 8. mount and journal is dirty, but trans committed in 6 will not be
>> replayed.
>>
>> This exception happens easily when this lun is used by only one node. If it
>> is used by multi-nodes, other node will replay its journal and its
>> journal super block will be updated after recovery like what this patch
>> does.
>>
>> ocfs2_recover_node->ocfs2_replay_journal.
>>
>> The following jbd2 journal can be generated by touching a new file after
>> journal is replayed, and seq 15 is the first valid commit, but first seq
>> is 13 in journal super block.
>> logdump:
>> Block 0: Journal Superblock
>> Seq: 0   Type: 4 (JBD2_SUPERBLOCK_V2)
>> Blocksize: 4096   Total Blocks: 32768   First Block: 1
>> First Commit ID: 13   Start Log Blknum: 1
>> Error: 0
>> Feature Compat: 0
>> Feature Incompat: 2 block64
>> Feature RO compat: 0
>> Journal UUID: 4ED3822C54294467A4F8E87D2BA4BC36
>> FS Share Cnt: 1   Dynamic Superblk Blknum: 0
>> Per Txn Block Limit    Journal: 0    Data: 0
>>
>> Block 1: Journal Commit Block
>> Seq: 14   Type: 2 (JBD2_COMMIT_BLOCK)
>>
>> Block 2: Journal Descriptor
>> Seq: 15   Type: 1 (JBD2_DESCRIPTOR_BLOCK)
>> No. Blocknum        Flags
>>  0. 587             none
>> UUID: 00000000000000000000000000000000
>>  1. 8257792         JBD2_FLAG_SAME_UUID
>>  2. 619             JBD2_FLAG_SAME_UUID
>>  3. 24772864        JBD2_FLAG_SAME_UUID
>>  4. 8257802         JBD2_FLAG_SAME_UUID
>>  5. 513             JBD2_FLAG_SAME_UUID JBD2_FLAG_LAST_TAG
>> ...
>> Block 7: Inode
>> Inode: 8257802   Mode: 0640   Generation: 57157641 (0x3682809)
>> FS Generation: 2839773110 (0xa9437fb6)
>> CRC32: 00000000   ECC: 0000
>> Type: Regular   Attr: 0x0   Flags: Valid
>> Dynamic Features: (0x1) InlineData
>> User: 0 (root)   Group: 0 (root)   Size: 7
>> Links: 1   Clusters: 0
>> ctime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
>> atime: 0x5de5d870 0x113181a1 -- Tue Dec  3 11:37:20.288457121 2019
>> mtime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
>> dtime: 0x0 -- Thu Jan  1 08:00:00 1970
>> ...
>> Block 9: Journal Commit Block
>> Seq: 15   Type: 2 (JBD2_COMMIT_BLOCK)
>>
>> The following is jouranl recovery log when recovering the upper jbd2
>> journal when mount again.
>> syslog:
>> [ 2265.648622] ocfs2: File system on device (252,1) was not unmounted cleanly, recovering it.
>> [ 2265.649695] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 0
>> [ 2265.650407] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 1
>> [ 2265.650409] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 2
>> [ 2265.650410] fs/jbd2/recovery.c:(jbd2_journal_recover, 278): JBD2: recovery, exit status 0, recovered transactions 13 to 13
>>
>> Due to first commit seq 13 recorded in journal super is not consistent
>> with the value recorded in block 1(seq is 14), journal recovery will be
>> terminated before seq 15 even though it is an unbroken commit, inode
>> 8257802 is a new file and it will be lost.
>>
>> Signed-off-by: Kai Li <li.kai4@h3c.com>
>> ---
>>  fs/ocfs2/journal.c | 8 ++++++++
>>  1 file changed, 8 insertions(+)
>>
>> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
>> index 1afe57f425a0..68ba354cf361 100644
>> --- a/fs/ocfs2/journal.c
>> +++ b/fs/ocfs2/journal.c
>> @@ -1066,6 +1066,14 @@ int ocfs2_journal_load(struct ocfs2_journal *journal, int local, int replayed)
>>  
>>  	ocfs2_clear_journal_error(osb->sb, journal->j_journal, osb->slot_num);
>>  
>> +	if (replayed) {
>> +		jbd2_journal_lock_updates(journal->j_journal);
>> +		status = jbd2_journal_flush(journal->j_journal);
> 
> What if jbd2_journal_flush gets failed? The 's_sequence' and 's_start'
> won't be reset, and I wonder if the problem still remains.
> 

Yes, but we don't want this to fail the mount process, instead we just log
an error and system administrator should know the result.

Thanks,
Joseph
piaojun Dec. 20, 2019, 9:13 a.m. UTC | #7
On 2019/12/20 9:11, Joseph Qi wrote:
> 
> 
> On 19/12/19 22:15, piaojun wrote:
>>
>>
>> On 2019/12/17 10:01, Kai Li wrote:
>>> If journal is dirty when mount, it will be replayed but jbd2 sb
>>> log tail cannot be updated to mark a new start because
>>> journal->j_flag has already been set with JBD2_ABORT first
>>> in journal_init_common. When a new transaction is committed, it
>>> will be recored in block 1 first(journal->j_tail is set to 1 in
>>> journal_reset).If emergency restart happens again before journal
>>> super block is updated unfortunately, the new recorded trans will
>>> not be replayed in the next mount.
>>>
>>> The following steps describe this procedure in detail.
>>> 1. mount and touch some files
>>> 2. these transactions are committed to journal area but not checkpointed
>>> 3. emergency restart
>>> 4. mount again and its journals are replayed
>>> 5. journal super block's first s_start is 1, but its s_seq is not updated
>>> 6. touch a new file and its trans is committed but not checkpointed
>>> 7. emergency restart again
>>> 8. mount and journal is dirty, but trans committed in 6 will not be
>>> replayed.
>>>
>>> This exception happens easily when this lun is used by only one node. If it
>>> is used by multi-nodes, other node will replay its journal and its
>>> journal super block will be updated after recovery like what this patch
>>> does.
>>>
>>> ocfs2_recover_node->ocfs2_replay_journal.
>>>
>>> The following jbd2 journal can be generated by touching a new file after
>>> journal is replayed, and seq 15 is the first valid commit, but first seq
>>> is 13 in journal super block.
>>> logdump:
>>> Block 0: Journal Superblock
>>> Seq: 0   Type: 4 (JBD2_SUPERBLOCK_V2)
>>> Blocksize: 4096   Total Blocks: 32768   First Block: 1
>>> First Commit ID: 13   Start Log Blknum: 1
>>> Error: 0
>>> Feature Compat: 0
>>> Feature Incompat: 2 block64
>>> Feature RO compat: 0
>>> Journal UUID: 4ED3822C54294467A4F8E87D2BA4BC36
>>> FS Share Cnt: 1   Dynamic Superblk Blknum: 0
>>> Per Txn Block Limit    Journal: 0    Data: 0
>>>
>>> Block 1: Journal Commit Block
>>> Seq: 14   Type: 2 (JBD2_COMMIT_BLOCK)
>>>
>>> Block 2: Journal Descriptor
>>> Seq: 15   Type: 1 (JBD2_DESCRIPTOR_BLOCK)
>>> No. Blocknum        Flags
>>>  0. 587             none
>>> UUID: 00000000000000000000000000000000
>>>  1. 8257792         JBD2_FLAG_SAME_UUID
>>>  2. 619             JBD2_FLAG_SAME_UUID
>>>  3. 24772864        JBD2_FLAG_SAME_UUID
>>>  4. 8257802         JBD2_FLAG_SAME_UUID
>>>  5. 513             JBD2_FLAG_SAME_UUID JBD2_FLAG_LAST_TAG
>>> ...
>>> Block 7: Inode
>>> Inode: 8257802   Mode: 0640   Generation: 57157641 (0x3682809)
>>> FS Generation: 2839773110 (0xa9437fb6)
>>> CRC32: 00000000   ECC: 0000
>>> Type: Regular   Attr: 0x0   Flags: Valid
>>> Dynamic Features: (0x1) InlineData
>>> User: 0 (root)   Group: 0 (root)   Size: 7
>>> Links: 1   Clusters: 0
>>> ctime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
>>> atime: 0x5de5d870 0x113181a1 -- Tue Dec  3 11:37:20.288457121 2019
>>> mtime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
>>> dtime: 0x0 -- Thu Jan  1 08:00:00 1970
>>> ...
>>> Block 9: Journal Commit Block
>>> Seq: 15   Type: 2 (JBD2_COMMIT_BLOCK)
>>>
>>> The following is jouranl recovery log when recovering the upper jbd2
>>> journal when mount again.
>>> syslog:
>>> [ 2265.648622] ocfs2: File system on device (252,1) was not unmounted cleanly, recovering it.
>>> [ 2265.649695] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 0
>>> [ 2265.650407] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 1
>>> [ 2265.650409] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 2
>>> [ 2265.650410] fs/jbd2/recovery.c:(jbd2_journal_recover, 278): JBD2: recovery, exit status 0, recovered transactions 13 to 13
>>>
>>> Due to first commit seq 13 recorded in journal super is not consistent
>>> with the value recorded in block 1(seq is 14), journal recovery will be
>>> terminated before seq 15 even though it is an unbroken commit, inode
>>> 8257802 is a new file and it will be lost.
>>>
>>> Signed-off-by: Kai Li <li.kai4@h3c.com>
>>> ---
>>>  fs/ocfs2/journal.c | 8 ++++++++
>>>  1 file changed, 8 insertions(+)
>>>
>>> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
>>> index 1afe57f425a0..68ba354cf361 100644
>>> --- a/fs/ocfs2/journal.c
>>> +++ b/fs/ocfs2/journal.c
>>> @@ -1066,6 +1066,14 @@ int ocfs2_journal_load(struct ocfs2_journal *journal, int local, int replayed)
>>>  
>>>  	ocfs2_clear_journal_error(osb->sb, journal->j_journal, osb->slot_num);
>>>  
>>> +	if (replayed) {
>>> +		jbd2_journal_lock_updates(journal->j_journal);
>>> +		status = jbd2_journal_flush(journal->j_journal);
>>
>> What if jbd2_journal_flush gets failed? The 's_sequence' and 's_start'
>> won't be reset, and I wonder if the problem still remains.
>>
> 
> Yes, but we don't want this to fail the mount process, instead we just log
> an error and system administrator should know the result.
> 
Thanks for your reply and I have another question about this issue. IMO
the second trans is not complete as jbd2 sb has not been updated, so we
do not need to replay it when mount again.

Jun
Likai Dec. 20, 2019, 9:33 a.m. UTC | #8
On 2019/12/20 17:14, piaojun wrote:
>
> On 2019/12/20 9:11, Joseph Qi wrote:
>>
>> On 19/12/19 22:15, piaojun wrote:
>>>
>>> On 2019/12/17 10:01, Kai Li wrote:
>>>> If journal is dirty when mount, it will be replayed but jbd2 sb
>>>> log tail cannot be updated to mark a new start because
>>>> journal->j_flag has already been set with JBD2_ABORT first
>>>> in journal_init_common. When a new transaction is committed, it
>>>> will be recored in block 1 first(journal->j_tail is set to 1 in
>>>> journal_reset).If emergency restart happens again before journal
>>>> super block is updated unfortunately, the new recorded trans will
>>>> not be replayed in the next mount.
>>>>
>>>> The following steps describe this procedure in detail.
>>>> 1. mount and touch some files
>>>> 2. these transactions are committed to journal area but not checkpointed
>>>> 3. emergency restart
>>>> 4. mount again and its journals are replayed
>>>> 5. journal super block's first s_start is 1, but its s_seq is not updated
>>>> 6. touch a new file and its trans is committed but not checkpointed
>>>> 7. emergency restart again
>>>> 8. mount and journal is dirty, but trans committed in 6 will not be
>>>> replayed.
>>>>
>>>> This exception happens easily when this lun is used by only one node. If it
>>>> is used by multi-nodes, other node will replay its journal and its
>>>> journal super block will be updated after recovery like what this patch
>>>> does.
>>>>
>>>> ocfs2_recover_node->ocfs2_replay_journal.
>>>>
>>>> The following jbd2 journal can be generated by touching a new file after
>>>> journal is replayed, and seq 15 is the first valid commit, but first seq
>>>> is 13 in journal super block.
>>>> logdump:
>>>> Block 0: Journal Superblock
>>>> Seq: 0   Type: 4 (JBD2_SUPERBLOCK_V2)
>>>> Blocksize: 4096   Total Blocks: 32768   First Block: 1
>>>> First Commit ID: 13   Start Log Blknum: 1
>>>> Error: 0
>>>> Feature Compat: 0
>>>> Feature Incompat: 2 block64
>>>> Feature RO compat: 0
>>>> Journal UUID: 4ED3822C54294467A4F8E87D2BA4BC36
>>>> FS Share Cnt: 1   Dynamic Superblk Blknum: 0
>>>> Per Txn Block Limit    Journal: 0    Data: 0
>>>>
>>>> Block 1: Journal Commit Block
>>>> Seq: 14   Type: 2 (JBD2_COMMIT_BLOCK)
>>>>
>>>> Block 2: Journal Descriptor
>>>> Seq: 15   Type: 1 (JBD2_DESCRIPTOR_BLOCK)
>>>> No. Blocknum        Flags
>>>>  0. 587             none
>>>> UUID: 00000000000000000000000000000000
>>>>  1. 8257792         JBD2_FLAG_SAME_UUID
>>>>  2. 619             JBD2_FLAG_SAME_UUID
>>>>  3. 24772864        JBD2_FLAG_SAME_UUID
>>>>  4. 8257802         JBD2_FLAG_SAME_UUID
>>>>  5. 513             JBD2_FLAG_SAME_UUID JBD2_FLAG_LAST_TAG
>>>> ...
>>>> Block 7: Inode
>>>> Inode: 8257802   Mode: 0640   Generation: 57157641 (0x3682809)
>>>> FS Generation: 2839773110 (0xa9437fb6)
>>>> CRC32: 00000000   ECC: 0000
>>>> Type: Regular   Attr: 0x0   Flags: Valid
>>>> Dynamic Features: (0x1) InlineData
>>>> User: 0 (root)   Group: 0 (root)   Size: 7
>>>> Links: 1   Clusters: 0
>>>> ctime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
>>>> atime: 0x5de5d870 0x113181a1 -- Tue Dec  3 11:37:20.288457121 2019
>>>> mtime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
>>>> dtime: 0x0 -- Thu Jan  1 08:00:00 1970
>>>> ...
>>>> Block 9: Journal Commit Block
>>>> Seq: 15   Type: 2 (JBD2_COMMIT_BLOCK)
>>>>
>>>> The following is jouranl recovery log when recovering the upper jbd2
>>>> journal when mount again.
>>>> syslog:
>>>> [ 2265.648622] ocfs2: File system on device (252,1) was not unmounted cleanly, recovering it.
>>>> [ 2265.649695] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 0
>>>> [ 2265.650407] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 1
>>>> [ 2265.650409] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 2
>>>> [ 2265.650410] fs/jbd2/recovery.c:(jbd2_journal_recover, 278): JBD2: recovery, exit status 0, recovered transactions 13 to 13
>>>>
>>>> Due to first commit seq 13 recorded in journal super is not consistent
>>>> with the value recorded in block 1(seq is 14), journal recovery will be
>>>> terminated before seq 15 even though it is an unbroken commit, inode
>>>> 8257802 is a new file and it will be lost.
>>>>
>>>> Signed-off-by: Kai Li <li.kai4@h3c.com>
>>>> ---
>>>>  fs/ocfs2/journal.c | 8 ++++++++
>>>>  1 file changed, 8 insertions(+)
>>>>
>>>> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
>>>> index 1afe57f425a0..68ba354cf361 100644
>>>> --- a/fs/ocfs2/journal.c
>>>> +++ b/fs/ocfs2/journal.c
>>>> @@ -1066,6 +1066,14 @@ int ocfs2_journal_load(struct ocfs2_journal *journal, int local, int replayed)
>>>>  
>>>>  	ocfs2_clear_journal_error(osb->sb, journal->j_journal, osb->slot_num);
>>>>  
>>>> +	if (replayed) {
>>>> +		jbd2_journal_lock_updates(journal->j_journal);
>>>> +		status = jbd2_journal_flush(journal->j_journal);
>>> What if jbd2_journal_flush gets failed? The 's_sequence' and 's_start'
>>> won't be reset, and I wonder if the problem still remains.
>>>
>> Yes, but we don't want this to fail the mount process, instead we just log
>> an error and system administrator should know the result.
>>
> Thanks for your reply and I have another question about this issue. IMO
> the second trans is not complete as jbd2 sb has not been updated, so we
> do not need to replay it when mount again.
>
> Jun
>
>
I don't think so. The problem is that jbd2 sb should be updated to mark
a new start after mount rather than whether trans committed later is
complete or not.

In fact , the trans is complete too as the commit log described.

Thanks
Jiangyiwen Dec. 20, 2019, 12:52 p.m. UTC | #9
On 2019/12/20 17:33, Likai wrote:
> On 2019/12/20 17:14, piaojun wrote:
>> On 2019/12/20 9:11, Joseph Qi wrote:
>>> On 19/12/19 22:15, piaojun wrote:
>>>> On 2019/12/17 10:01, Kai Li wrote:
>>>>> If journal is dirty when mount, it will be replayed but jbd2 sb
>>>>> log tail cannot be updated to mark a new start because
>>>>> journal->j_flag has already been set with JBD2_ABORT first
>>>>> in journal_init_common. When a new transaction is committed, it
>>>>> will be recored in block 1 first(journal->j_tail is set to 1 in
>>>>> journal_reset).If emergency restart happens again before journal
>>>>> super block is updated unfortunately, the new recorded trans will
>>>>> not be replayed in the next mount.
>>>>>
>>>>> The following steps describe this procedure in detail.
>>>>> 1. mount and touch some files
>>>>> 2. these transactions are committed to journal area but not checkpointed
>>>>> 3. emergency restart
>>>>> 4. mount again and its journals are replayed
>>>>> 5. journal super block's first s_start is 1, but its s_seq is not updated
>>>>> 6. touch a new file and its trans is committed but not checkpointed

Hi,

I wonder that in this step, does the function 
jbd2_journal_commit_transaction() return?
I understand only jbd2_journal_commit_transaction() return it means the 
transaction
is committed completely, and the s_seq can be updated in
jbd2_journal_commit_transaction()->jbd2_update_log_tail(), so I don't 
know how
this scenario happened.

If emergency restart happens in before jbd2_journal_commit_transaction() 
return,
I think this transaction shouldn't be a valid transaction.

Can you explain where the specific function is executed?

Thanks,
Yiwen.

>>>>> 7. emergency restart again
>>>>> 8. mount and journal is dirty, but trans committed in 6 will not be
>>>>> replayed.
>>>>>
>>>>> This exception happens easily when this lun is used by only one node. If it
>>>>> is used by multi-nodes, other node will replay its journal and its
>>>>> journal super block will be updated after recovery like what this patch
>>>>> does.
>>>>>
>>>>> ocfs2_recover_node->ocfs2_replay_journal.
>>>>>
>>>>> The following jbd2 journal can be generated by touching a new file after
>>>>> journal is replayed, and seq 15 is the first valid commit, but first seq
>>>>> is 13 in journal super block.
>>>>> logdump:
>>>>> Block 0: Journal Superblock
>>>>> Seq: 0   Type: 4 (JBD2_SUPERBLOCK_V2)
>>>>> Blocksize: 4096   Total Blocks: 32768   First Block: 1
>>>>> First Commit ID: 13   Start Log Blknum: 1
>>>>> Error: 0
>>>>> Feature Compat: 0
>>>>> Feature Incompat: 2 block64
>>>>> Feature RO compat: 0
>>>>> Journal UUID: 4ED3822C54294467A4F8E87D2BA4BC36
>>>>> FS Share Cnt: 1   Dynamic Superblk Blknum: 0
>>>>> Per Txn Block Limit    Journal: 0    Data: 0
>>>>>
>>>>> Block 1: Journal Commit Block
>>>>> Seq: 14   Type: 2 (JBD2_COMMIT_BLOCK)
>>>>>
>>>>> Block 2: Journal Descriptor
>>>>> Seq: 15   Type: 1 (JBD2_DESCRIPTOR_BLOCK)
>>>>> No. Blocknum        Flags
>>>>>   0. 587             none
>>>>> UUID: 00000000000000000000000000000000
>>>>>   1. 8257792         JBD2_FLAG_SAME_UUID
>>>>>   2. 619             JBD2_FLAG_SAME_UUID
>>>>>   3. 24772864        JBD2_FLAG_SAME_UUID
>>>>>   4. 8257802         JBD2_FLAG_SAME_UUID
>>>>>   5. 513             JBD2_FLAG_SAME_UUID JBD2_FLAG_LAST_TAG
>>>>> ...
>>>>> Block 7: Inode
>>>>> Inode: 8257802   Mode: 0640   Generation: 57157641 (0x3682809)
>>>>> FS Generation: 2839773110 (0xa9437fb6)
>>>>> CRC32: 00000000   ECC: 0000
>>>>> Type: Regular   Attr: 0x0   Flags: Valid
>>>>> Dynamic Features: (0x1) InlineData
>>>>> User: 0 (root)   Group: 0 (root)   Size: 7
>>>>> Links: 1   Clusters: 0
>>>>> ctime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
>>>>> atime: 0x5de5d870 0x113181a1 -- Tue Dec  3 11:37:20.288457121 2019
>>>>> mtime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
>>>>> dtime: 0x0 -- Thu Jan  1 08:00:00 1970
>>>>> ...
>>>>> Block 9: Journal Commit Block
>>>>> Seq: 15   Type: 2 (JBD2_COMMIT_BLOCK)
>>>>>
>>>>> The following is jouranl recovery log when recovering the upper jbd2
>>>>> journal when mount again.
>>>>> syslog:
>>>>> [ 2265.648622] ocfs2: File system on device (252,1) was not unmounted cleanly, recovering it.
>>>>> [ 2265.649695] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 0
>>>>> [ 2265.650407] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 1
>>>>> [ 2265.650409] fs/jbd2/recovery.c:(do_one_pass, 449): Starting recovery pass 2
>>>>> [ 2265.650410] fs/jbd2/recovery.c:(jbd2_journal_recover, 278): JBD2: recovery, exit status 0, recovered transactions 13 to 13
>>>>>
>>>>> Due to first commit seq 13 recorded in journal super is not consistent
>>>>> with the value recorded in block 1(seq is 14), journal recovery will be
>>>>> terminated before seq 15 even though it is an unbroken commit, inode
>>>>> 8257802 is a new file and it will be lost.
>>>>>
>>>>> Signed-off-by: Kai Li <li.kai4@h3c.com>
>>>>> ---
>>>>>   fs/ocfs2/journal.c | 8 ++++++++
>>>>>   1 file changed, 8 insertions(+)
>>>>>
>>>>> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
>>>>> index 1afe57f425a0..68ba354cf361 100644
>>>>> --- a/fs/ocfs2/journal.c
>>>>> +++ b/fs/ocfs2/journal.c
>>>>> @@ -1066,6 +1066,14 @@ int ocfs2_journal_load(struct ocfs2_journal *journal, int local, int replayed)
>>>>>   
>>>>>   	ocfs2_clear_journal_error(osb->sb, journal->j_journal, osb->slot_num);
>>>>>   
>>>>> +	if (replayed) {
>>>>> +		jbd2_journal_lock_updates(journal->j_journal);
>>>>> +		status = jbd2_journal_flush(journal->j_journal);
>>>> What if jbd2_journal_flush gets failed? The 's_sequence' and 's_start'
>>>> won't be reset, and I wonder if the problem still remains.
>>>>
>>> Yes, but we don't want this to fail the mount process, instead we just log
>>> an error and system administrator should know the result.
>>>
>> Thanks for your reply and I have another question about this issue. IMO
>> the second trans is not complete as jbd2 sb has not been updated, so we
>> do not need to replay it when mount again.
>>
>> Jun
>>
>>
> I don't think so. The problem is that jbd2 sb should be updated to mark
> a new start after mount rather than whether trans committed later is
> complete or not.
>
> In fact , the trans is complete too as the commit log described.
>
> Thanks
>
>
> _______________________________________________
> Ocfs2-devel mailing list
> Ocfs2-devel@oss.oracle.com
> https://oss.oracle.com/mailman/listinfo/ocfs2-devel
>
> .
>
Changwei Ge Dec. 21, 2019, 7:24 a.m. UTC | #10
On 12/20/19 8:52 PM, Jiangyiwen wrote:
> On 2019/12/20 17:33, Likai wrote:
>> On 2019/12/20 17:14, piaojun wrote:
>>> On 2019/12/20 9:11, Joseph Qi wrote:
>>>> On 19/12/19 22:15, piaojun wrote:
>>>>> On 2019/12/17 10:01, Kai Li wrote:
>>>>>> If journal is dirty when mount, it will be replayed but jbd2 sb
>>>>>> log tail cannot be updated to mark a new start because
>>>>>> journal->j_flag has already been set with JBD2_ABORT first
>>>>>> in journal_init_common. When a new transaction is committed, it
>>>>>> will be recored in block 1 first(journal->j_tail is set to 1 in
>>>>>> journal_reset).If emergency restart happens again before journal
>>>>>> super block is updated unfortunately, the new recorded trans will
>>>>>> not be replayed in the next mount.
>>>>>>
>>>>>> The following steps describe this procedure in detail.
>>>>>> 1. mount and touch some files
>>>>>> 2. these transactions are committed to journal area but not 
>>>>>> checkpointed
>>>>>> 3. emergency restart
>>>>>> 4. mount again and its journals are replayed
>>>>>> 5. journal super block's first s_start is 1, but its s_seq is not 
>>>>>> updated
>>>>>> 6. touch a new file and its trans is committed but not checkpointed
> 
> Hi,
> 
> I wonder that in this step, does the function 
> jbd2_journal_commit_transaction() return?
> I understand only jbd2_journal_commit_transaction() return it means the 
> transaction
> is committed completely, and the s_seq can be updated in
> jbd2_journal_commit_transaction()->jbd2_update_log_tail(), so I don't 
> know how
> this scenario happened.
> 
> If emergency restart happens in before jbd2_journal_commit_transaction() 

The trick is that jbd2 kernel thread even doesn't have a chance to to 
update tail. Assuming that a timepoint sits between *mount completion* 
and the *first iteration* of committing work that jbd2 thread.

	-Changwei

> return,
> I think this transaction shouldn't be a valid transaction.
> 
> Can you explain where the specific function is executed?
> 
> Thanks,
> Yiwen.
> 
>>>>>> 7. emergency restart again
>>>>>> 8. mount and journal is dirty, but trans committed in 6 will not be
>>>>>> replayed.
>>>>>>
>>>>>> This exception happens easily when this lun is used by only one 
>>>>>> node. If it
>>>>>> is used by multi-nodes, other node will replay its journal and its
>>>>>> journal super block will be updated after recovery like what this 
>>>>>> patch
>>>>>> does.
>>>>>>
>>>>>> ocfs2_recover_node->ocfs2_replay_journal.
>>>>>>
>>>>>> The following jbd2 journal can be generated by touching a new file 
>>>>>> after
>>>>>> journal is replayed, and seq 15 is the first valid commit, but 
>>>>>> first seq
>>>>>> is 13 in journal super block.
>>>>>> logdump:
>>>>>> Block 0: Journal Superblock
>>>>>> Seq: 0   Type: 4 (JBD2_SUPERBLOCK_V2)
>>>>>> Blocksize: 4096   Total Blocks: 32768   First Block: 1
>>>>>> First Commit ID: 13   Start Log Blknum: 1
>>>>>> Error: 0
>>>>>> Feature Compat: 0
>>>>>> Feature Incompat: 2 block64
>>>>>> Feature RO compat: 0
>>>>>> Journal UUID: 4ED3822C54294467A4F8E87D2BA4BC36
>>>>>> FS Share Cnt: 1   Dynamic Superblk Blknum: 0
>>>>>> Per Txn Block Limit    Journal: 0    Data: 0
>>>>>>
>>>>>> Block 1: Journal Commit Block
>>>>>> Seq: 14   Type: 2 (JBD2_COMMIT_BLOCK)
>>>>>>
>>>>>> Block 2: Journal Descriptor
>>>>>> Seq: 15   Type: 1 (JBD2_DESCRIPTOR_BLOCK)
>>>>>> No. Blocknum        Flags
>>>>>>   0. 587             none
>>>>>> UUID: 00000000000000000000000000000000
>>>>>>   1. 8257792         JBD2_FLAG_SAME_UUID
>>>>>>   2. 619             JBD2_FLAG_SAME_UUID
>>>>>>   3. 24772864        JBD2_FLAG_SAME_UUID
>>>>>>   4. 8257802         JBD2_FLAG_SAME_UUID
>>>>>>   5. 513             JBD2_FLAG_SAME_UUID JBD2_FLAG_LAST_TAG
>>>>>> ...
>>>>>> Block 7: Inode
>>>>>> Inode: 8257802   Mode: 0640   Generation: 57157641 (0x3682809)
>>>>>> FS Generation: 2839773110 (0xa9437fb6)
>>>>>> CRC32: 00000000   ECC: 0000
>>>>>> Type: Regular   Attr: 0x0   Flags: Valid
>>>>>> Dynamic Features: (0x1) InlineData
>>>>>> User: 0 (root)   Group: 0 (root)   Size: 7
>>>>>> Links: 1   Clusters: 0
>>>>>> ctime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
>>>>>> atime: 0x5de5d870 0x113181a1 -- Tue Dec  3 11:37:20.288457121 2019
>>>>>> mtime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
>>>>>> dtime: 0x0 -- Thu Jan  1 08:00:00 1970
>>>>>> ...
>>>>>> Block 9: Journal Commit Block
>>>>>> Seq: 15   Type: 2 (JBD2_COMMIT_BLOCK)
>>>>>>
>>>>>> The following is jouranl recovery log when recovering the upper jbd2
>>>>>> journal when mount again.
>>>>>> syslog:
>>>>>> [ 2265.648622] ocfs2: File system on device (252,1) was not 
>>>>>> unmounted cleanly, recovering it.
>>>>>> [ 2265.649695] fs/jbd2/recovery.c:(do_one_pass, 449): Starting 
>>>>>> recovery pass 0
>>>>>> [ 2265.650407] fs/jbd2/recovery.c:(do_one_pass, 449): Starting 
>>>>>> recovery pass 1
>>>>>> [ 2265.650409] fs/jbd2/recovery.c:(do_one_pass, 449): Starting 
>>>>>> recovery pass 2
>>>>>> [ 2265.650410] fs/jbd2/recovery.c:(jbd2_journal_recover, 278): 
>>>>>> JBD2: recovery, exit status 0, recovered transactions 13 to 13
>>>>>>
>>>>>> Due to first commit seq 13 recorded in journal super is not 
>>>>>> consistent
>>>>>> with the value recorded in block 1(seq is 14), journal recovery 
>>>>>> will be
>>>>>> terminated before seq 15 even though it is an unbroken commit, inode
>>>>>> 8257802 is a new file and it will be lost.
>>>>>>
>>>>>> Signed-off-by: Kai Li <li.kai4@h3c.com>
>>>>>> ---
>>>>>>   fs/ocfs2/journal.c | 8 ++++++++
>>>>>>   1 file changed, 8 insertions(+)
>>>>>>
>>>>>> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
>>>>>> index 1afe57f425a0..68ba354cf361 100644
>>>>>> --- a/fs/ocfs2/journal.c
>>>>>> +++ b/fs/ocfs2/journal.c
>>>>>> @@ -1066,6 +1066,14 @@ int ocfs2_journal_load(struct ocfs2_journal 
>>>>>> *journal, int local, int replayed)
>>>>>>       ocfs2_clear_journal_error(osb->sb, journal->j_journal, 
>>>>>> osb->slot_num);
>>>>>> +    if (replayed) {
>>>>>> +        jbd2_journal_lock_updates(journal->j_journal);
>>>>>> +        status = jbd2_journal_flush(journal->j_journal);
>>>>> What if jbd2_journal_flush gets failed? The 's_sequence' and 's_start'
>>>>> won't be reset, and I wonder if the problem still remains.
>>>>>
>>>> Yes, but we don't want this to fail the mount process, instead we 
>>>> just log
>>>> an error and system administrator should know the result.
>>>>
>>> Thanks for your reply and I have another question about this issue. IMO
>>> the second trans is not complete as jbd2 sb has not been updated, so we
>>> do not need to replay it when mount again.
>>>
>>> Jun
>>>
>>>
>> I don't think so. The problem is that jbd2 sb should be updated to mark
>> a new start after mount rather than whether trans committed later is
>> complete or not.
>>
>> In fact , the trans is complete too as the commit log described.
>>
>> Thanks
>>
>>
>> _______________________________________________
>> Ocfs2-devel mailing list
>> Ocfs2-devel@oss.oracle.com
>> https://oss.oracle.com/mailman/listinfo/ocfs2-devel
>>
>> .
>>
>
Jiangyiwen Dec. 23, 2019, 1:54 a.m. UTC | #11
On 2019/12/21 15:24, Changwei Ge wrote:
>
>
> On 12/20/19 8:52 PM, Jiangyiwen wrote:
>> On 2019/12/20 17:33, Likai wrote:
>>> On 2019/12/20 17:14, piaojun wrote:
>>>> On 2019/12/20 9:11, Joseph Qi wrote:
>>>>> On 19/12/19 22:15, piaojun wrote:
>>>>>> On 2019/12/17 10:01, Kai Li wrote:
>>>>>>> If journal is dirty when mount, it will be replayed but jbd2 sb
>>>>>>> log tail cannot be updated to mark a new start because
>>>>>>> journal->j_flag has already been set with JBD2_ABORT first
>>>>>>> in journal_init_common. When a new transaction is committed, it
>>>>>>> will be recored in block 1 first(journal->j_tail is set to 1 in
>>>>>>> journal_reset).If emergency restart happens again before journal
>>>>>>> super block is updated unfortunately, the new recorded trans will
>>>>>>> not be replayed in the next mount.
>>>>>>>
>>>>>>> The following steps describe this procedure in detail.
>>>>>>> 1. mount and touch some files
>>>>>>> 2. these transactions are committed to journal area but not 
>>>>>>> checkpointed
>>>>>>> 3. emergency restart
>>>>>>> 4. mount again and its journals are replayed
>>>>>>> 5. journal super block's first s_start is 1, but its s_seq is 
>>>>>>> not updated
>>>>>>> 6. touch a new file and its trans is committed but not checkpointed
>>
>> Hi,
>>
>> I wonder that in this step, does the function 
>> jbd2_journal_commit_transaction() return?
>> I understand only jbd2_journal_commit_transaction() return it means 
>> the transaction
>> is committed completely, and the s_seq can be updated in
>> jbd2_journal_commit_transaction()->jbd2_update_log_tail(), so I don't 
>> know how
>> this scenario happened.
>>
>> If emergency restart happens in before jbd2_journal_commit_transaction() 
>
> The trick is that jbd2 kernel thread even doesn't have a chance to to 
> update tail. Assuming that a timepoint sits between *mount completion* 
> and the *first iteration* of committing work that jbd2 thread.
>

Hi Changwei,

So I think if *first iteration* of committing work in jbd2 kernel thread 
is not
completed, and then the transaction should not be considered a valid
transaction.

In addition, since we use ordered mode in jbd2, filesystem only ensure
metadata consistency not data consistency. In above scenario, the filesystem
is still normal without any damage.

Thanks,
Yiwen.

>     -Changwei
>
>> return,
>> I think this transaction shouldn't be a valid transaction.
>>
>> Can you explain where the specific function is executed?
>>
>> Thanks,
>> Yiwen.
>>
>>>>>>> 7. emergency restart again
>>>>>>> 8. mount and journal is dirty, but trans committed in 6 will not be
>>>>>>> replayed.
>>>>>>>
>>>>>>> This exception happens easily when this lun is used by only one 
>>>>>>> node. If it
>>>>>>> is used by multi-nodes, other node will replay its journal and its
>>>>>>> journal super block will be updated after recovery like what 
>>>>>>> this patch
>>>>>>> does.
>>>>>>>
>>>>>>> ocfs2_recover_node->ocfs2_replay_journal.
>>>>>>>
>>>>>>> The following jbd2 journal can be generated by touching a new 
>>>>>>> file after
>>>>>>> journal is replayed, and seq 15 is the first valid commit, but 
>>>>>>> first seq
>>>>>>> is 13 in journal super block.
>>>>>>> logdump:
>>>>>>> Block 0: Journal Superblock
>>>>>>> Seq: 0   Type: 4 (JBD2_SUPERBLOCK_V2)
>>>>>>> Blocksize: 4096   Total Blocks: 32768   First Block: 1
>>>>>>> First Commit ID: 13   Start Log Blknum: 1
>>>>>>> Error: 0
>>>>>>> Feature Compat: 0
>>>>>>> Feature Incompat: 2 block64
>>>>>>> Feature RO compat: 0
>>>>>>> Journal UUID: 4ED3822C54294467A4F8E87D2BA4BC36
>>>>>>> FS Share Cnt: 1   Dynamic Superblk Blknum: 0
>>>>>>> Per Txn Block Limit    Journal: 0    Data: 0
>>>>>>>
>>>>>>> Block 1: Journal Commit Block
>>>>>>> Seq: 14   Type: 2 (JBD2_COMMIT_BLOCK)
>>>>>>>
>>>>>>> Block 2: Journal Descriptor
>>>>>>> Seq: 15   Type: 1 (JBD2_DESCRIPTOR_BLOCK)
>>>>>>> No. Blocknum        Flags
>>>>>>>   0. 587             none
>>>>>>> UUID: 00000000000000000000000000000000
>>>>>>>   1. 8257792         JBD2_FLAG_SAME_UUID
>>>>>>>   2. 619             JBD2_FLAG_SAME_UUID
>>>>>>>   3. 24772864        JBD2_FLAG_SAME_UUID
>>>>>>>   4. 8257802         JBD2_FLAG_SAME_UUID
>>>>>>>   5. 513             JBD2_FLAG_SAME_UUID JBD2_FLAG_LAST_TAG
>>>>>>> ...
>>>>>>> Block 7: Inode
>>>>>>> Inode: 8257802   Mode: 0640   Generation: 57157641 (0x3682809)
>>>>>>> FS Generation: 2839773110 (0xa9437fb6)
>>>>>>> CRC32: 00000000   ECC: 0000
>>>>>>> Type: Regular   Attr: 0x0   Flags: Valid
>>>>>>> Dynamic Features: (0x1) InlineData
>>>>>>> User: 0 (root)   Group: 0 (root)   Size: 7
>>>>>>> Links: 1   Clusters: 0
>>>>>>> ctime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
>>>>>>> atime: 0x5de5d870 0x113181a1 -- Tue Dec  3 11:37:20.288457121 2019
>>>>>>> mtime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
>>>>>>> dtime: 0x0 -- Thu Jan  1 08:00:00 1970
>>>>>>> ...
>>>>>>> Block 9: Journal Commit Block
>>>>>>> Seq: 15   Type: 2 (JBD2_COMMIT_BLOCK)
>>>>>>>
>>>>>>> The following is jouranl recovery log when recovering the upper 
>>>>>>> jbd2
>>>>>>> journal when mount again.
>>>>>>> syslog:
>>>>>>> [ 2265.648622] ocfs2: File system on device (252,1) was not 
>>>>>>> unmounted cleanly, recovering it.
>>>>>>> [ 2265.649695] fs/jbd2/recovery.c:(do_one_pass, 449): Starting 
>>>>>>> recovery pass 0
>>>>>>> [ 2265.650407] fs/jbd2/recovery.c:(do_one_pass, 449): Starting 
>>>>>>> recovery pass 1
>>>>>>> [ 2265.650409] fs/jbd2/recovery.c:(do_one_pass, 449): Starting 
>>>>>>> recovery pass 2
>>>>>>> [ 2265.650410] fs/jbd2/recovery.c:(jbd2_journal_recover, 278): 
>>>>>>> JBD2: recovery, exit status 0, recovered transactions 13 to 13
>>>>>>>
>>>>>>> Due to first commit seq 13 recorded in journal super is not 
>>>>>>> consistent
>>>>>>> with the value recorded in block 1(seq is 14), journal recovery 
>>>>>>> will be
>>>>>>> terminated before seq 15 even though it is an unbroken commit, 
>>>>>>> inode
>>>>>>> 8257802 is a new file and it will be lost.
>>>>>>>
>>>>>>> Signed-off-by: Kai Li <li.kai4@h3c.com>
>>>>>>> ---
>>>>>>>   fs/ocfs2/journal.c | 8 ++++++++
>>>>>>>   1 file changed, 8 insertions(+)
>>>>>>>
>>>>>>> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
>>>>>>> index 1afe57f425a0..68ba354cf361 100644
>>>>>>> --- a/fs/ocfs2/journal.c
>>>>>>> +++ b/fs/ocfs2/journal.c
>>>>>>> @@ -1066,6 +1066,14 @@ int ocfs2_journal_load(struct 
>>>>>>> ocfs2_journal *journal, int local, int replayed)
>>>>>>>       ocfs2_clear_journal_error(osb->sb, journal->j_journal, 
>>>>>>> osb->slot_num);
>>>>>>> +    if (replayed) {
>>>>>>> + jbd2_journal_lock_updates(journal->j_journal);
>>>>>>> +        status = jbd2_journal_flush(journal->j_journal);
>>>>>> What if jbd2_journal_flush gets failed? The 's_sequence' and 
>>>>>> 's_start'
>>>>>> won't be reset, and I wonder if the problem still remains.
>>>>>>
>>>>> Yes, but we don't want this to fail the mount process, instead we 
>>>>> just log
>>>>> an error and system administrator should know the result.
>>>>>
>>>> Thanks for your reply and I have another question about this issue. 
>>>> IMO
>>>> the second trans is not complete as jbd2 sb has not been updated, 
>>>> so we
>>>> do not need to replay it when mount again.
>>>>
>>>> Jun
>>>>
>>>>
>>> I don't think so. The problem is that jbd2 sb should be updated to mark
>>> a new start after mount rather than whether trans committed later is
>>> complete or not.
>>>
>>> In fact , the trans is complete too as the commit log described.
>>>
>>> Thanks
>>>
>>>
>>> _______________________________________________
>>> Ocfs2-devel mailing list
>>> Ocfs2-devel@oss.oracle.com
>>> https://oss.oracle.com/mailman/listinfo/ocfs2-devel
>>>
>>> .
>>>
>>
>
> .
>
Changwei Ge Jan. 1, 2020, 3:15 a.m. UTC | #12
Hi Yiwen,

Sorry for late reply since I was on a vocation last week :-)

On 12/23/19 9:54 AM, Jiangyiwen wrote:
> 
> 
> On 2019/12/21 15:24, Changwei Ge wrote:
>>
>>
>> On 12/20/19 8:52 PM, Jiangyiwen wrote:
>>> On 2019/12/20 17:33, Likai wrote:
>>>> On 2019/12/20 17:14, piaojun wrote:
>>>>> On 2019/12/20 9:11, Joseph Qi wrote:
>>>>>> On 19/12/19 22:15, piaojun wrote:
>>>>>>> On 2019/12/17 10:01, Kai Li wrote:
>>>>>>>> If journal is dirty when mount, it will be replayed but jbd2 sb
>>>>>>>> log tail cannot be updated to mark a new start because
>>>>>>>> journal->j_flag has already been set with JBD2_ABORT first
>>>>>>>> in journal_init_common. When a new transaction is committed, it
>>>>>>>> will be recored in block 1 first(journal->j_tail is set to 1 in
>>>>>>>> journal_reset).If emergency restart happens again before journal
>>>>>>>> super block is updated unfortunately, the new recorded trans will
>>>>>>>> not be replayed in the next mount.
>>>>>>>>
>>>>>>>> The following steps describe this procedure in detail.
>>>>>>>> 1. mount and touch some files
>>>>>>>> 2. these transactions are committed to journal area but not 
>>>>>>>> checkpointed
>>>>>>>> 3. emergency restart
>>>>>>>> 4. mount again and its journals are replayed
>>>>>>>> 5. journal super block's first s_start is 1, but its s_seq is 
>>>>>>>> not updated
>>>>>>>> 6. touch a new file and its trans is committed but not checkpointed
>>>
>>> Hi,
>>>
>>> I wonder that in this step, does the function 
>>> jbd2_journal_commit_transaction() return?
>>> I understand only jbd2_journal_commit_transaction() return it means 
>>> the transaction
>>> is committed completely, and the s_seq can be updated in
>>> jbd2_journal_commit_transaction()->jbd2_update_log_tail(), so I don't 
>>> know how
>>> this scenario happened.
>>>
>>> If emergency restart happens in before jbd2_journal_commit_transaction() 
>>
>> The trick is that jbd2 kernel thread even doesn't have a chance to to 
>> update tail. Assuming that a timepoint sits between *mount completion* 
>> and the *first iteration* of committing work that jbd2 thread.
>>
> 
> Hi Changwei,
> 
> So I think if *first iteration* of committing work in jbd2 kernel thread 
> is not
> completed, and then the transaction should not be considered a valid
> transaction.

Um...
Here I think we are talking about *log tail* update. If jbd2 kernel 
thread already works for more than one iteration, it might have a chance 
to update log tail during committing trans. But if even no once of work 
iteration, it definitely can't update that tail to mark the boundary of 
uncheckpointed transactions.

> 
> In addition, since we use ordered mode in jbd2, filesystem only ensure
> metadata consistency not data consistency. In above scenario, the 
> filesystem
> is still normal without any damage.

True, the filesystem meta should be consistent. But the transaction is 
actually committed and valid. Relaying it does no harm.

In fact, I think it's a normal/standard use case of jbd2 that call 
jbd2_journal_flush() after relaying the entire journal. Please refer to 
ext4 and peer-help recovery progress in ocfs2.

Thanks,
Changwei

> 
> Thanks,
> Yiwen.
> 
>>     -Changwei
>>
>>> return,
>>> I think this transaction shouldn't be a valid transaction.
>>>
>>> Can you explain where the specific function is executed?
>>>
>>> Thanks,
>>> Yiwen.
>>>
>>>>>>>> 7. emergency restart again
>>>>>>>> 8. mount and journal is dirty, but trans committed in 6 will not be
>>>>>>>> replayed.
>>>>>>>>
>>>>>>>> This exception happens easily when this lun is used by only one 
>>>>>>>> node. If it
>>>>>>>> is used by multi-nodes, other node will replay its journal and its
>>>>>>>> journal super block will be updated after recovery like what 
>>>>>>>> this patch
>>>>>>>> does.
>>>>>>>>
>>>>>>>> ocfs2_recover_node->ocfs2_replay_journal.
>>>>>>>>
>>>>>>>> The following jbd2 journal can be generated by touching a new 
>>>>>>>> file after
>>>>>>>> journal is replayed, and seq 15 is the first valid commit, but 
>>>>>>>> first seq
>>>>>>>> is 13 in journal super block.
>>>>>>>> logdump:
>>>>>>>> Block 0: Journal Superblock
>>>>>>>> Seq: 0   Type: 4 (JBD2_SUPERBLOCK_V2)
>>>>>>>> Blocksize: 4096   Total Blocks: 32768   First Block: 1
>>>>>>>> First Commit ID: 13   Start Log Blknum: 1
>>>>>>>> Error: 0
>>>>>>>> Feature Compat: 0
>>>>>>>> Feature Incompat: 2 block64
>>>>>>>> Feature RO compat: 0
>>>>>>>> Journal UUID: 4ED3822C54294467A4F8E87D2BA4BC36
>>>>>>>> FS Share Cnt: 1   Dynamic Superblk Blknum: 0
>>>>>>>> Per Txn Block Limit    Journal: 0    Data: 0
>>>>>>>>
>>>>>>>> Block 1: Journal Commit Block
>>>>>>>> Seq: 14   Type: 2 (JBD2_COMMIT_BLOCK)
>>>>>>>>
>>>>>>>> Block 2: Journal Descriptor
>>>>>>>> Seq: 15   Type: 1 (JBD2_DESCRIPTOR_BLOCK)
>>>>>>>> No. Blocknum        Flags
>>>>>>>>   0. 587             none
>>>>>>>> UUID: 00000000000000000000000000000000
>>>>>>>>   1. 8257792         JBD2_FLAG_SAME_UUID
>>>>>>>>   2. 619             JBD2_FLAG_SAME_UUID
>>>>>>>>   3. 24772864        JBD2_FLAG_SAME_UUID
>>>>>>>>   4. 8257802         JBD2_FLAG_SAME_UUID
>>>>>>>>   5. 513             JBD2_FLAG_SAME_UUID JBD2_FLAG_LAST_TAG
>>>>>>>> ...
>>>>>>>> Block 7: Inode
>>>>>>>> Inode: 8257802   Mode: 0640   Generation: 57157641 (0x3682809)
>>>>>>>> FS Generation: 2839773110 (0xa9437fb6)
>>>>>>>> CRC32: 00000000   ECC: 0000
>>>>>>>> Type: Regular   Attr: 0x0   Flags: Valid
>>>>>>>> Dynamic Features: (0x1) InlineData
>>>>>>>> User: 0 (root)   Group: 0 (root)   Size: 7
>>>>>>>> Links: 1   Clusters: 0
>>>>>>>> ctime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
>>>>>>>> atime: 0x5de5d870 0x113181a1 -- Tue Dec  3 11:37:20.288457121 2019
>>>>>>>> mtime: 0x5de5d870 0x11104c61 -- Tue Dec  3 11:37:20.286280801 2019
>>>>>>>> dtime: 0x0 -- Thu Jan  1 08:00:00 1970
>>>>>>>> ...
>>>>>>>> Block 9: Journal Commit Block
>>>>>>>> Seq: 15   Type: 2 (JBD2_COMMIT_BLOCK)
>>>>>>>>
>>>>>>>> The following is jouranl recovery log when recovering the upper 
>>>>>>>> jbd2
>>>>>>>> journal when mount again.
>>>>>>>> syslog:
>>>>>>>> [ 2265.648622] ocfs2: File system on device (252,1) was not 
>>>>>>>> unmounted cleanly, recovering it.
>>>>>>>> [ 2265.649695] fs/jbd2/recovery.c:(do_one_pass, 449): Starting 
>>>>>>>> recovery pass 0
>>>>>>>> [ 2265.650407] fs/jbd2/recovery.c:(do_one_pass, 449): Starting 
>>>>>>>> recovery pass 1
>>>>>>>> [ 2265.650409] fs/jbd2/recovery.c:(do_one_pass, 449): Starting 
>>>>>>>> recovery pass 2
>>>>>>>> [ 2265.650410] fs/jbd2/recovery.c:(jbd2_journal_recover, 278): 
>>>>>>>> JBD2: recovery, exit status 0, recovered transactions 13 to 13
>>>>>>>>
>>>>>>>> Due to first commit seq 13 recorded in journal super is not 
>>>>>>>> consistent
>>>>>>>> with the value recorded in block 1(seq is 14), journal recovery 
>>>>>>>> will be
>>>>>>>> terminated before seq 15 even though it is an unbroken commit, 
>>>>>>>> inode
>>>>>>>> 8257802 is a new file and it will be lost.
>>>>>>>>
>>>>>>>> Signed-off-by: Kai Li <li.kai4@h3c.com>
>>>>>>>> ---
>>>>>>>>   fs/ocfs2/journal.c | 8 ++++++++
>>>>>>>>   1 file changed, 8 insertions(+)
>>>>>>>>
>>>>>>>> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
>>>>>>>> index 1afe57f425a0..68ba354cf361 100644
>>>>>>>> --- a/fs/ocfs2/journal.c
>>>>>>>> +++ b/fs/ocfs2/journal.c
>>>>>>>> @@ -1066,6 +1066,14 @@ int ocfs2_journal_load(struct 
>>>>>>>> ocfs2_journal *journal, int local, int replayed)
>>>>>>>>       ocfs2_clear_journal_error(osb->sb, journal->j_journal, 
>>>>>>>> osb->slot_num);
>>>>>>>> +    if (replayed) {
>>>>>>>> + jbd2_journal_lock_updates(journal->j_journal);
>>>>>>>> +        status = jbd2_journal_flush(journal->j_journal);
>>>>>>> What if jbd2_journal_flush gets failed? The 's_sequence' and 
>>>>>>> 's_start'
>>>>>>> won't be reset, and I wonder if the problem still remains.
>>>>>>>
>>>>>> Yes, but we don't want this to fail the mount process, instead we 
>>>>>> just log
>>>>>> an error and system administrator should know the result.
>>>>>>
>>>>> Thanks for your reply and I have another question about this issue. 
>>>>> IMO
>>>>> the second trans is not complete as jbd2 sb has not been updated, 
>>>>> so we
>>>>> do not need to replay it when mount again.
>>>>>
>>>>> Jun
>>>>>
>>>>>
>>>> I don't think so. The problem is that jbd2 sb should be updated to mark
>>>> a new start after mount rather than whether trans committed later is
>>>> complete or not.
>>>>
>>>> In fact , the trans is complete too as the commit log described.
>>>>
>>>> Thanks
>>>>
>>>>
>>>> _______________________________________________
>>>> Ocfs2-devel mailing list
>>>> Ocfs2-devel@oss.oracle.com
>>>> https://oss.oracle.com/mailman/listinfo/ocfs2-devel
>>>>
>>>> .
>>>>
>>>
>>
>> .
>>
>

Patch
diff mbox series

diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
index 1afe57f425a0..68ba354cf361 100644
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -1066,6 +1066,14 @@  int ocfs2_journal_load(struct ocfs2_journal *journal, int local, int replayed)
 
 	ocfs2_clear_journal_error(osb->sb, journal->j_journal, osb->slot_num);
 
+	if (replayed) {
+		jbd2_journal_lock_updates(journal->j_journal);
+		status = jbd2_journal_flush(journal->j_journal);
+		jbd2_journal_unlock_updates(journal->j_journal);
+		if (status < 0)
+			mlog_errno(status);
+	}
+
 	status = ocfs2_journal_toggle_dirty(osb, 1, replayed);
 	if (status < 0) {
 		mlog_errno(status);