| Message ID | 51D6A5A0.1080300@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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@huawei.com> > Cc: Jie Liu <jeff.liu@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);
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);
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@huawei.com> Cc: Jie Liu <jeff.liu@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(-)