Likai
2019-Dec-16 12:12 UTC
[Ocfs2-devel] [PATCH v2] ocfs2: call journal flush to mark journal as empty after journal recovery when mount
On 2019/12/16 18:02, Joseph Qi wrote:> > On 19/12/12 14:00, 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 at h3c.com> >> --- >> fs/ocfs2/journal.c | 9 +++++++++ >> 1 file changed, 9 insertions(+) >> >> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c >> index 1afe57f425a0..5c7a489f47b0 100644 >> --- a/fs/ocfs2/journal.c >> +++ b/fs/ocfs2/journal.c >> @@ -1066,6 +1066,15 @@ 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) { >> + mlog(ML_NOTICE, "journal recovery complete"); > I don't think this log is appropriate, or we can change it to something like: > "Journal is dirty, wipe it first"? > > Thanks, > JosephThis log is not used to interpret journal flush's purpose and calling journal flush to make jbd2 super block become normal should be a requisite operation internally, maybe a mark should be better I think if necessary. In addition, ocfs2 prints a log like 'ocfs2: File system on device (%s) was not unmounted cleanly, recovering it' before, and journal has already been replayed in jbd2_journal_load->jbd2_journal_recover, this log just means that it is done here. So I don't think it is inappropriate, could you think abort my proposal again? Thanks>> + 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); >>
Joseph Qi
2019-Dec-16 13:36 UTC
[Ocfs2-devel] [PATCH v2] ocfs2: call journal flush to mark journal as empty after journal recovery when mount
On 19/12/16 20:12, Likai wrote:> On 2019/12/16 18:02, Joseph Qi wrote: >> >> On 19/12/12 14:00, 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 at h3c.com> >>> --- >>> fs/ocfs2/journal.c | 9 +++++++++ >>> 1 file changed, 9 insertions(+) >>> >>> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c >>> index 1afe57f425a0..5c7a489f47b0 100644 >>> --- a/fs/ocfs2/journal.c >>> +++ b/fs/ocfs2/journal.c >>> @@ -1066,6 +1066,15 @@ 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) { >>> + mlog(ML_NOTICE, "journal recovery complete"); >> I don't think this log is appropriate, or we can change it to something like: >> "Journal is dirty, wipe it first"? >> >> Thanks, >> Joseph > This log is not used to interpret journal flush's purpose and calling > journal flush to make jbd2 super block become normal should be a > requisite operation internally, > maybe a mark should be better I think if necessary. > In addition, ocfs2 prints a log like 'ocfs2: File system on device (%s) > was not unmounted cleanly, recovering it' before, > and journal has already been replayed in > jbd2_journal_load->jbd2_journal_recover, this log just means that it is > done here. > So I don't think it is inappropriate, could you think abort my proposal > again? >Not really, just think that this log has no actual meaning. Or we can simply remove it. Thanks, Joseph