| Message ID | 1473394107-3399-1-git-send-email-houtao1@huawei.com (mailing list archive) |
|---|---|
| State | Rejected, archived |
| Headers | show |
On Fri, Sep 09, 2016 at 12:08:27PM +0800, Hou Tao wrote: > For delaylog-enabled fs, the only th_type is XFS_TRANS_CHECKPOINT, > but the value of XFS_TRANS_CHECKPOINT had been change from 42 to 40 > by xfs commit 61e63ec (xfs: consolidate superblock logging functions), > so return trans_type[type] directly will be incorrect. > And there is no flag for delaylog testing, so the suboptimal solution > is to use super v5 flag instead. For pre-v5 fs used by kernel after > commit 61e63ec, the result of xlog_trans_type will still be incorrect. delaylog and v5 superblocks are completely unrelated and so this is incorrect. > before patch: > (1) v5 fs > TRAN: type: SWAPEXT tid: 321be024 num_items: 2 > TRANS: tid:0x772d0805 type:SWAPEXT #items:37 trans:0x772d0805 q:0x559104d71bc0 > > after patch: > (2) v5 fs > TRAN: type: CHECKPOINT tid: 321be024 num_items: 2 > TRANS: tid:0x772d0805 type:SWAPEXT #items:37 trans:0x772d0805 q:0x559104d71bc0 And so v4 filesystems are still incorrect. Indeed, when delaylog is enabled, the only transaction type in the log is "CHECKPOINT" - the whole "trans type" stuff has gone away from the kernel and only exists as this in xfs_log_format.h: /* * The only type valid for th_type in CIL-enabled file system logs: */ #define XFS_TRANS_CHECKPOINT 40 IOWs, most of the logprint code is for printing log information from pre-delaylog kernels. IOWs, for the anyone using a 3.0+ kernel, the "trans type" output from xfs_logprint is completely useless information, so we should probably either put it behind a command line option or remove it completely... Cheers, Dave.
>> but the value of XFS_TRANS_CHECKPOINT had been change from 42 to 40 >> by xfs commit 61e63ec (xfs: consolidate superblock logging functions), >> so return trans_type[type] directly will be incorrect. >> And there is no flag for delaylog testing, so the suboptimal solution >> is to use super v5 flag instead. For pre-v5 fs used by kernel after >> commit 61e63ec, the result of xlog_trans_type will still be incorrect. > > delaylog and v5 superblocks are completely unrelated and so this is > incorrect. I don't agree. As we can see from the commit log, v5 superblock was supported after making delaylog as the only option, so v5 superblock implies delaylog. Commit 93b8a5854f247138e401471a9c3b82ccb62ff608 makes the delaylog as the only option, and its date is "Tue Dec 6 21:58:07 2011". Commit 04a1e6c5b222b089c6960dfc5352002002a4355f adds the support of v5 superblock, and its date is "Wed Apr 3 16:11:31 2013". > And so v4 filesystems are still incorrect. > Partial yes: For v4 filesystem before 3.19 (commit 61e63ec), the result is still correct. > IOWs, most of the logprint code is for printing log information from > pre-delaylog kernels. IOWs, for the anyone using a 3.0+ kernel, the > "trans type" output from xfs_logprint is completely useless > information, so we should probably either put it behind a command > line option or remove it completely... I prefer the command line option over removing it. Pre-delaylog kernel need it and some cases of xfstests rely on the transaction type string. The command line will be used to tell whether or not it is a delaylog-enabled xfs, and if it's a v5 superblock, it must be a delaylog-enabled xfs. I will send a v2 patch.
On Wed, Sep 14, 2016 at 09:02:54AM +0800, Hou Tao wrote: > >> but the value of XFS_TRANS_CHECKPOINT had been change from 42 to 40 > >> by xfs commit 61e63ec (xfs: consolidate superblock logging functions), > >> so return trans_type[type] directly will be incorrect. > >> And there is no flag for delaylog testing, so the suboptimal solution > >> is to use super v5 flag instead. For pre-v5 fs used by kernel after > >> commit 61e63ec, the result of xlog_trans_type will still be incorrect. > > > > delaylog and v5 superblocks are completely unrelated and so this is > > incorrect. > I don't agree. As we can see from the commit log, v5 superblock was supported > after making delaylog as the only option, so v5 superblock implies delaylog. You can disagree, but that doesn't make your argument correct. Superblock versions and features define changes to the on-disk format, and delaylog was specifically crafted to avoid changing the on-disk fomats. Tying detection of transaction type numbering to an unrelated on-disk feature change is simply wrong. No ifs, not buts, it's just wrong. > Commit 93b8a5854f247138e401471a9c3b82ccb62ff608 makes the delaylog as the only > option, and its date is "Tue Dec 6 21:58:07 2011". > > Commit 04a1e6c5b222b089c6960dfc5352002002a4355f adds the support of v5 superblock, > and its date is "Wed Apr 3 16:11:31 2013". Sure, but that's irrelevant because these are unrelated features. > > And so v4 filesystems are still incorrect. > > > Partial yes: For v4 filesystem before 3.19 (commit 61e63ec), the result > is still correct. Actually, it was introduced in 3.20-rc1, aka 4.0. It was propagated into xfsprogs 4.2.0-rc1. The trans type code in logprint is really for legacy filesystems with kernels older than 3.0. I don't see much point in trying to hack legacy support into the TOT diagnostic tool, especailly as it is trivial to pull a logprint from a previous release if such support is actually necessary. e.g: $ git checkout -b old_logprint v3.2.3 $ make And now you have a logprint/xfs_logprint binary that you can use for diagnostics of the pre-delaylog log format. Removing functionality from the TOT code base does not mean that functionality is lost - it's still in the revision contorl system and a minute away from being usable if it's ever needed. > > IOWs, most of the logprint code is for printing log information from > > pre-delaylog kernels. IOWs, for the anyone using a 3.0+ kernel, the > > "trans type" output from xfs_logprint is completely useless > > information, so we should probably either put it behind a command > > line option or remove it completely... > I prefer the command line option over removing it. Pre-delaylog kernel > need it and some cases of xfstests rely on the transaction type string. > > The command line will be used to tell whether or not it is a delaylog-enabled > xfs, and if it's a v5 superblock, it must be a delaylog-enabled xfs. Users won't know this, because "delaylog" is something that has long been deprecated and lots of users don't even know it exists. Really, just remove the transaction type printing from logprint and both developers and users can continue to ignore it like we have been for the past few years.... Cheers, Dave.
> Tying detection of transaction type numbering to an > unrelated on-disk feature change is simply wrong. No ifs, not buts, > it's just wrong. Yes, I agree with you. > Actually, it was introduced in 3.20-rc1, aka 4.0. It was propagated > into xfsprogs 4.2.0-rc1. The trans type code in logprint is really > for legacy filesystems with kernels older than 3.0. > I don't see much point in trying to hack legacy support > into the TOT diagnostic tool, especailly as it is trivial to pull > a logprint from a previous release if such support is actually > necessary. e.g: > > $ git checkout -b old_logprint v3.2.3 > $ make > > And now you have a logprint/xfs_logprint binary that you can use for > diagnostics of the pre-delaylog log format. > > Removing functionality from the TOT code base does not mean that > functionality is lost - it's still in the revision contorl system > and a minute away from being usable if it's ever needed. I just think about the compatibility things too much. > Users won't know this, because "delaylog" is something that has long > been deprecated and lots of users don't even know it exists. > > Really, just remove the transaction type printing from logprint and > both developers and users can continue to ignore it like we have > been for the past few years.... Thanks for your comment. I will send a new patch to remove the transaction type printing.
diff --git a/include/libxlog.h b/include/libxlog.h index 0a11ec8..b0d2870 100644 --- a/include/libxlog.h +++ b/include/libxlog.h @@ -104,13 +104,12 @@ extern int xlog_test_footer(struct xlog *log); extern int xlog_recover(struct xlog *log, int readonly); extern void xlog_recover_print_data(char *p, int len); extern void xlog_recover_print_logitem(xlog_recover_item_t *item); -extern void xlog_recover_print_trans_head(xlog_recover_t *tr); +extern void xlog_recover_print_trans_head(xlog_recover_t *tr, int delaylog); extern int xlog_print_find_oldest(struct xlog *log, xfs_daddr_t *last_blk); /* for transactional view */ -extern void xlog_recover_print_trans_head(xlog_recover_t *tr); extern void xlog_recover_print_trans(xlog_recover_t *trans, - struct list_head *itemq, int print); + struct list_head *itemq, int print, int delaylog); extern int xlog_do_recovery_pass(struct xlog *log, xfs_daddr_t head_blk, xfs_daddr_t tail_blk, int pass); extern int xlog_recover_do_trans(struct xlog *log, xlog_recover_t *trans, diff --git a/logprint/log_misc.c b/logprint/log_misc.c index 479fc14..066ac59 100644 --- a/logprint/log_misc.c +++ b/logprint/log_misc.c @@ -28,7 +28,7 @@ #define NO_ERROR (0) static int logBBsize; -char *trans_type[] = { +static char *trans_type[] = { "", "SETATTR", "SETATTR_SIZE", @@ -207,8 +207,30 @@ xlog_print_find_tid(xlog_tid_t tid, uint was_cont) return 1; } /* xlog_print_find_tid */ +/* + * For delaylog-enabled fs, the only th_type is XFS_TRANS_CHECKPOINT, + * but the value of XFS_TRANS_CHECKPOINT had been change from 42 to 40 + * by xfs commit 61e63ec (xfs: consolidate superblock logging functions), + * so return trans_type[type] directly will be incorrect. + * + * And there is no flag for delaylog testing, so the suboptimal solution + * is to use super v5 flag instead. For pre-v5 fs used by kernel after + * commit 61e63ec, the result of xlog_trans_type will still be incorrect. + */ +int +xlog_delaylog_on(struct xfs_sb *sb) +{ + return (XFS_SB_VERSION_NUM(sb) == XFS_SB_VERSION_5); +} + +const char * +xlog_trans_type(uint type, int delaylog) +{ + return delaylog ? "CHECKPOINT" : trans_type[type]; +} + int -xlog_print_trans_header(char **ptr, int len) +xlog_print_trans_header(char **ptr, int len, int delaylog) { xfs_trans_header_t *h; char *cptr = *ptr; @@ -234,7 +256,8 @@ xlog_print_trans_header(char **ptr, int len) } h = (xfs_trans_header_t *)cptr; printf(_(" type: %s tid: %x num_items: %d\n"), - trans_type[h->th_type], h->th_tid, h->th_num_items); + xlog_trans_type(h->th_type, delaylog), + h->th_tid, h->th_num_items); return 0; } /* xlog_print_trans_header */ @@ -825,6 +848,7 @@ xlog_print_record( char *buf, *ptr; int read_len, skip, lost_context = 0; int ret, n, i, j, k; + int delaylog; if (print_no_print) return NO_ERROR; @@ -917,6 +941,7 @@ xlog_print_record( } ptr = buf; + delaylog = xlog_delaylog_on(&log->l_mp->m_sb); for (i=0; i<num_ops; i++) { int continued; @@ -955,7 +980,8 @@ xlog_print_record( if (be32_to_cpu(op_head->oh_len) != 0) { if (*(uint *)ptr == XFS_TRANS_HEADER_MAGIC) { skip = xlog_print_trans_header(&ptr, - be32_to_cpu(op_head->oh_len)); + be32_to_cpu(op_head->oh_len), + delaylog); } else { switch (*(unsigned short *)ptr) { case XFS_LI_BUF: { diff --git a/logprint/log_print_all.c b/logprint/log_print_all.c index 0fe354b..ddc5475 100644 --- a/logprint/log_print_all.c +++ b/logprint/log_print_all.c @@ -482,7 +482,8 @@ void xlog_recover_print_trans( xlog_recover_t *trans, struct list_head *itemq, - int print) + int print, + int delaylog) { xlog_recover_item_t *item; @@ -490,7 +491,7 @@ xlog_recover_print_trans( return; print_xlog_record_line(); - xlog_recover_print_trans_head(trans); + xlog_recover_print_trans_head(trans, delaylog); list_for_each_entry(item, itemq, ri_list) xlog_recover_print_item(item); } diff --git a/logprint/log_print_trans.c b/logprint/log_print_trans.c index 9bf2b37..cf653ad 100644 --- a/logprint/log_print_trans.c +++ b/logprint/log_print_trans.c @@ -22,10 +22,12 @@ void xlog_recover_print_trans_head( - xlog_recover_t *tr) + xlog_recover_t *tr, + int delaylog) { printf(_("TRANS: tid:0x%x type:%s #items:%d trans:0x%x q:0x%lx\n"), - tr->r_log_tid, trans_type[tr->r_theader.th_type], + tr->r_log_tid, + xlog_trans_type(tr->r_theader.th_type, delaylog), tr->r_theader.th_num_items, tr->r_theader.th_tid, (long)&tr->r_itemq); } @@ -36,7 +38,8 @@ xlog_recover_do_trans( xlog_recover_t *trans, int pass) { - xlog_recover_print_trans(trans, &trans->r_itemq, 3); + xlog_recover_print_trans(trans, &trans->r_itemq, 3, + xlog_delaylog_on(&log->l_mp->m_sb)); return 0; } diff --git a/logprint/logprint.h b/logprint/logprint.h index 0c03c08..95d13d5 100644 --- a/logprint/logprint.h +++ b/logprint/logprint.h @@ -18,6 +18,8 @@ #ifndef LOGPRINT_H #define LOGPRINT_H +struct xfs_sb; + /* command line flags */ extern int print_data; extern int print_only_data; @@ -30,7 +32,8 @@ extern int print_no_data; extern int print_no_print; /* exports */ -extern char *trans_type[]; +extern int xlog_delaylog_on(struct xfs_sb *sb); +extern const char *xlog_trans_type(uint type, int delaylog); extern void xlog_print_lseek(struct xlog *, int, xfs_daddr_t, int);
For delaylog-enabled fs, the only th_type is XFS_TRANS_CHECKPOINT, but the value of XFS_TRANS_CHECKPOINT had been change from 42 to 40 by xfs commit 61e63ec (xfs: consolidate superblock logging functions), so return trans_type[type] directly will be incorrect. And there is no flag for delaylog testing, so the suboptimal solution is to use super v5 flag instead. For pre-v5 fs used by kernel after commit 61e63ec, the result of xlog_trans_type will still be incorrect. before patch: (1) v5 fs TRAN: type: SWAPEXT tid: 321be024 num_items: 2 TRANS: tid:0x772d0805 type:SWAPEXT #items:37 trans:0x772d0805 q:0x559104d71bc0 after patch: (2) v5 fs TRAN: type: CHECKPOINT tid: 321be024 num_items: 2 TRANS: tid:0x772d0805 type:SWAPEXT #items:37 trans:0x772d0805 q:0x559104d71bc0 Signed-off-by: Hou Tao <houtao1@huawei.com> --- include/libxlog.h | 5 ++--- logprint/log_misc.c | 34 ++++++++++++++++++++++++++++++---- logprint/log_print_all.c | 5 +++-- logprint/log_print_trans.c | 9 ++++++--- logprint/logprint.h | 5 ++++- 5 files changed, 45 insertions(+), 13 deletions(-)