Younger Liu
2013-Jul-05 10:53 UTC
[Ocfs2-devel] [PATCH V2] ocfs2: lighten up allocate transaction
The issue scenario is as following:
When fallocating a very large disk space for a small file,
__ocfs2_extend_allocation attempts to get a very large transaction.
For some journal sizes, there may be not enough room for this
transaction, and the fallocate will fail.
The patch below extents & restarts the transaction as necessary while
allocating space, and should work with even the smallest journal.
This patch refers ext4 resize.
Test:
# mkfs.ocfs2 -b 4K -C 32K -T datafiles /dev/sdc
...(jounral size is 32M)
# mount.ocfs2 /dev/sdc /mnt/ocfs2/
# touch /mnt/ocfs2/1.log
# fallocate -o 0 -l 400G /mnt/ocfs2/1.log
fallocate: /mnt/ocfs2/1.log: fallocate failed: Cannot allocate memory
# tail -f /var/log/messages
[ 7372.278591] JBD: fallocate wants too many credits (2051 > 2048)
[ 7372.278597] (fallocate,6438,0):__ocfs2_extend_allocation:709 ERROR: status =
-12
[ 7372.278603] (fallocate,6438,0):ocfs2_allocate_unwritten_extents:1504 ERROR:
status = -12
[ 7372.278607] (fallocate,6438,0):__ocfs2_change_file_space:1955 ERROR: status =
-12
^C
With this patch, the test works well.
Compared with V1, add trace point in ocfs2_allocate_extend_trans.
Signed-off-by: Younger Liu <younger.liu at huawei.com>
Cc: Jie Liu <jeff.liu at oracle.com>
---
fs/ocfs2/file.c | 6 +-----
fs/ocfs2/journal.c | 36 ++++++++++++++++++++++++++++++++++++
fs/ocfs2/journal.h | 11 +++++++++++
fs/ocfs2/ocfs2_trace.h | 2 ++
4 files changed, 50 insertions(+), 5 deletions(-)
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 05c0bb1..4943918 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -666,11 +666,7 @@ restarted_transaction:
} else {
BUG_ON(why != RESTART_TRANS);
- /* TODO: This can be more intelligent. */
- credits = ocfs2_calc_extend_credits(osb->sb,
- &fe->id2.i_list,
- clusters_to_add);
- status = ocfs2_extend_trans(handle, credits);
+ status = ocfs2_allocate_extend_trans(handle, 1);
if (status < 0) {
/* handle still has to be committed at
* this point. */
diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
index 8eccfab..1d389fb 100644
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -455,6 +455,42 @@ bail:
return status;
}
+/*
+ * If we have fewer than thresh credits, extend by OCFS2_MAX_TRANS_DATA.
+ * If that fails, restart the transaction & regain write access for the
+ * buffer head which is used for metadata modifications.
+ * Taken from Ext4: extend_or_restart_transaction()
+ */
+int ocfs2_allocate_extend_trans(handle_t *handle, int thresh)
+{
+ int status, old_nblks;
+
+ BUG_ON(!handle);
+
+ old_nblks = handle->h_buffer_credits;
+ trace_ocfs2_allocate_extend_trans(old_nblks, thresh);
+
+ if (old_nblks < thresh)
+ return 0;
+
+ status = jbd2_journal_extend(handle, OCFS2_MAX_TRANS_DATA);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ if (status > 0) {
+ status = jbd2_journal_restart(handle, OCFS2_MAX_TRANS_DATA);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ }
+
+bail:
+ return status;
+}
+
struct ocfs2_triggers {
struct jbd2_buffer_trigger_type ot_triggers;
int ot_offset;
diff --git a/fs/ocfs2/journal.h b/fs/ocfs2/journal.h
index a3385b6..62a26bd 100644
--- a/fs/ocfs2/journal.h
+++ b/fs/ocfs2/journal.h
@@ -259,6 +259,17 @@ handle_t *ocfs2_start_trans(struct ocfs2_super *osb,
int ocfs2_commit_trans(struct ocfs2_super *osb,
handle_t *handle);
int ocfs2_extend_trans(handle_t *handle, int nblocks);
+int ocfs2_allocate_extend_trans(handle_t *handle,
+ int thresh);
+
+/*
+ * Define an arbitrary limit for the amount of data we will anticipate
+ * writing to any given transaction. For unbounded transactions such as
+ * fallocate(2) we can write more than this, but we always
+ * start off at the maximum transaction size and grow the transaction
+ * optimistically as we go.
+ */
+#define OCFS2_MAX_TRANS_DATA 64U
/*
* Create access is for when we get a newly created buffer and we're
diff --git a/fs/ocfs2/ocfs2_trace.h b/fs/ocfs2/ocfs2_trace.h
index 3b481f4..1b60c62 100644
--- a/fs/ocfs2/ocfs2_trace.h
+++ b/fs/ocfs2/ocfs2_trace.h
@@ -2579,6 +2579,8 @@ DEFINE_OCFS2_INT_INT_EVENT(ocfs2_extend_trans);
DEFINE_OCFS2_INT_EVENT(ocfs2_extend_trans_restart);
+DEFINE_OCFS2_INT_INT_EVENT(ocfs2_allocate_extend_trans);
+
DEFINE_OCFS2_ULL_ULL_UINT_UINT_EVENT(ocfs2_journal_access);
DEFINE_OCFS2_ULL_EVENT(ocfs2_journal_dirty);
--
1.7.9.7
Jeff Liu
2013-Jul-05 11:46 UTC
[Ocfs2-devel] [PATCH V2] ocfs2: lighten up allocate transaction
On 07/05/2013 06:53 PM, Younger Liu wrote:> The issue scenario is as following: > When fallocating a very large disk space for a small file, > __ocfs2_extend_allocation attempts to get a very large transaction. > For some journal sizes, there may be not enough room for this > transaction, and the fallocate will fail. > > The patch below extents & restarts the transaction as necessary while > allocating space, and should work with even the smallest journal. > This patch refers ext4 resize. > > Test: > # mkfs.ocfs2 -b 4K -C 32K -T datafiles /dev/sdc > ...(jounral size is 32M) > # mount.ocfs2 /dev/sdc /mnt/ocfs2/ > # touch /mnt/ocfs2/1.log > # fallocate -o 0 -l 400G /mnt/ocfs2/1.log > fallocate: /mnt/ocfs2/1.log: fallocate failed: Cannot allocate memory > # tail -f /var/log/messages > [ 7372.278591] JBD: fallocate wants too many credits (2051 > 2048) > [ 7372.278597] (fallocate,6438,0):__ocfs2_extend_allocation:709 ERROR: status = -12 > [ 7372.278603] (fallocate,6438,0):ocfs2_allocate_unwritten_extents:1504 ERROR: status = -12 > [ 7372.278607] (fallocate,6438,0):__ocfs2_change_file_space:1955 ERROR: status = -12 > ^C > > With this patch, the test works well. > > Compared with V1, add trace point in ocfs2_allocate_extend_trans. > > Signed-off-by: Younger Liu <younger.liu at huawei.com> > Cc: Jie Liu <jeff.liu at oracle.com> > --- > fs/ocfs2/file.c | 6 +----- > fs/ocfs2/journal.c | 36 ++++++++++++++++++++++++++++++++++++ > fs/ocfs2/journal.h | 11 +++++++++++ > fs/ocfs2/ocfs2_trace.h | 2 ++ > 4 files changed, 50 insertions(+), 5 deletions(-) > > diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c > index 05c0bb1..4943918 100644 > --- a/fs/ocfs2/file.c > +++ b/fs/ocfs2/file.c > @@ -666,11 +666,7 @@ restarted_transaction: > } else { > BUG_ON(why != RESTART_TRANS); > > - /* TODO: This can be more intelligent. */ > - credits = ocfs2_calc_extend_credits(osb->sb, > - &fe->id2.i_list, > - clusters_to_add); > - status = ocfs2_extend_trans(handle, credits); > + status = ocfs2_allocate_extend_trans(handle, 1); > if (status < 0) { > /* handle still has to be committed at > * this point. */ > diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c > index 8eccfab..1d389fb 100644 > --- a/fs/ocfs2/journal.c > +++ b/fs/ocfs2/journal.c > @@ -455,6 +455,42 @@ bail: > return status; > } > > +/* > + * If we have fewer than thresh credits, extend by OCFS2_MAX_TRANS_DATA. > + * If that fails, restart the transaction & regain write access for the > + * buffer head which is used for metadata modifications. > + * Taken from Ext4: extend_or_restart_transaction() > + */ > +int ocfs2_allocate_extend_trans(handle_t *handle, int thresh) > +{ > + int status, old_nblks; > + > + BUG_ON(!handle); > + > + old_nblks = handle->h_buffer_credits; > + trace_ocfs2_allocate_extend_trans(old_nblks, thresh); > + > + if (old_nblks < thresh) > + return 0; > + > + status = jbd2_journal_extend(handle, OCFS2_MAX_TRANS_DATA); > + if (status < 0) { > + mlog_errno(status); > + goto bail; > + } > + > + if (status > 0) { > + status = jbd2_journal_restart(handle, OCFS2_MAX_TRANS_DATA); > + if (status < 0) { > + mlog_errno(status); > + goto bail; > + }I guess you missed one comment in my previous review that is we can omit the 'goto' statement as well as the curly braces around it. BTW, I detected a number of trailing whitespace error when applying this patch, please check it too. That is all right, you don't need to post a revised version until get some feedbacks from others. Thanks, -Jeff> + } > + > +bail: > + return status; > +} > + > struct ocfs2_triggers { > struct jbd2_buffer_trigger_type ot_triggers; > int ot_offset; > diff --git a/fs/ocfs2/journal.h b/fs/ocfs2/journal.h > index a3385b6..62a26bd 100644 > --- a/fs/ocfs2/journal.h > +++ b/fs/ocfs2/journal.h > @@ -259,6 +259,17 @@ handle_t *ocfs2_start_trans(struct ocfs2_super *osb, > int ocfs2_commit_trans(struct ocfs2_super *osb, > handle_t *handle); > int ocfs2_extend_trans(handle_t *handle, int nblocks); > +int ocfs2_allocate_extend_trans(handle_t *handle, > + int thresh); > + > +/* > + * Define an arbitrary limit for the amount of data we will anticipate > + * writing to any given transaction. For unbounded transactions such as > + * fallocate(2) we can write more than this, but we always > + * start off at the maximum transaction size and grow the transaction > + * optimistically as we go. > + */ > +#define OCFS2_MAX_TRANS_DATA 64U > > /* > * Create access is for when we get a newly created buffer and we're > diff --git a/fs/ocfs2/ocfs2_trace.h b/fs/ocfs2/ocfs2_trace.h > index 3b481f4..1b60c62 100644 > --- a/fs/ocfs2/ocfs2_trace.h > +++ b/fs/ocfs2/ocfs2_trace.h > @@ -2579,6 +2579,8 @@ DEFINE_OCFS2_INT_INT_EVENT(ocfs2_extend_trans); > > DEFINE_OCFS2_INT_EVENT(ocfs2_extend_trans_restart); > > +DEFINE_OCFS2_INT_INT_EVENT(ocfs2_allocate_extend_trans); > + > DEFINE_OCFS2_ULL_ULL_UINT_UINT_EVENT(ocfs2_journal_access); > > DEFINE_OCFS2_ULL_EVENT(ocfs2_journal_dirty);