Hi Joseph, On 07/06/2016 12:21 PM, Joseph Qi wrote: > NAK, if ocfs2_try_to_free_truncate_log fails, it will lead to double > ocfs2_inode_unlock and then BUG.
Thanks for pointing out this! Will fix this and resend. Eric > > On 2016/6/22 17:07, Eric Ren wrote: >> The testcase "mmaptruncate" in ocfs2 test suite always fails with >> ENOSPC error on small volume (say less than 10G). This testcase >> creates 2 threads T1/T2 which race to "truncate"/"extend" a same >> file repeatedly. Specifically, T1 truncates 1/2 size of a small file >> while T2 extend to 100% size. The main bitmap will quickly run out >> of space because the "truncate" code prevent truncate log from being >> flushed by ocfs2_schedule_truncate_log_flush(osb, 1), while truncate >> log may have cached lots of clusters. >> >> So retry to allocate after flushing truncate log when ENOSPC is >> returned. And we cannot reuse the deleted blocks before the transaction >> committed. Fortunately, we already have a function to do this - >> ocfs2_try_to_free_truncate_log(). Just need to remove the "static" >> modifier and put it into a right place. >> >> Signed-off-by: Eric Ren <z...@suse.com> >> --- >> fs/ocfs2/alloc.c | 37 +++++++++++++++++++++++++++++++++++++ >> fs/ocfs2/alloc.h | 2 ++ >> fs/ocfs2/aops.c | 37 ------------------------------------- >> fs/ocfs2/suballoc.c | 17 ++++++++++++++++- >> 4 files changed, 55 insertions(+), 38 deletions(-) >> >> diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c >> index 460c0ce..7dabbc3 100644 >> --- a/fs/ocfs2/alloc.c >> +++ b/fs/ocfs2/alloc.c >> @@ -6106,6 +6106,43 @@ void ocfs2_schedule_truncate_log_flush(struct >> ocfs2_super *osb, >> } >> } >> >> +/* >> + * Try to flush truncate logs if we can free enough clusters from it. >> + * As for return value, "< 0" means error, "0" no space and "1" means >> + * we have freed enough spaces and let the caller try to allocate again. >> + */ >> +int ocfs2_try_to_free_truncate_log(struct ocfs2_super *osb, >> + unsigned int needed) >> +{ >> + tid_t target; >> + int ret = 0; >> + unsigned int truncated_clusters; >> + >> + inode_lock(osb->osb_tl_inode); >> + truncated_clusters = osb->truncated_clusters; >> + inode_unlock(osb->osb_tl_inode); >> + >> + /* >> + * Check whether we can succeed in allocating if we free >> + * the truncate log. >> + */ >> + if (truncated_clusters < needed) >> + goto out; >> + >> + ret = ocfs2_flush_truncate_log(osb); >> + if (ret) { >> + mlog_errno(ret); >> + goto out; >> + } >> + >> + if (jbd2_journal_start_commit(osb->journal->j_journal, &target)) { >> + jbd2_log_wait_commit(osb->journal->j_journal, target); >> + ret = 1; >> + } >> +out: >> + return ret; >> +} >> + >> static int ocfs2_get_truncate_log_info(struct ocfs2_super *osb, >> int slot_num, >> struct inode **tl_inode, >> diff --git a/fs/ocfs2/alloc.h b/fs/ocfs2/alloc.h >> index f3dc1b0..4a5152e 100644 >> --- a/fs/ocfs2/alloc.h >> +++ b/fs/ocfs2/alloc.h >> @@ -188,6 +188,8 @@ int ocfs2_truncate_log_append(struct ocfs2_super *osb, >> u64 start_blk, >> unsigned int num_clusters); >> int __ocfs2_flush_truncate_log(struct ocfs2_super *osb); >> +int ocfs2_try_to_free_truncate_log(struct ocfs2_super *osb, >> + unsigned int needed); >> >> /* >> * Process local structure which describes the block unlinks done >> diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c >> index c034edf..1802aef 100644 >> --- a/fs/ocfs2/aops.c >> +++ b/fs/ocfs2/aops.c >> @@ -1645,43 +1645,6 @@ static int ocfs2_zero_tail(struct inode *inode, >> struct buffer_head *di_bh, >> return ret; >> } >> >> -/* >> - * Try to flush truncate logs if we can free enough clusters from it. >> - * As for return value, "< 0" means error, "0" no space and "1" means >> - * we have freed enough spaces and let the caller try to allocate again. >> - */ >> -static int ocfs2_try_to_free_truncate_log(struct ocfs2_super *osb, >> - unsigned int needed) >> -{ >> - tid_t target; >> - int ret = 0; >> - unsigned int truncated_clusters; >> - >> - inode_lock(osb->osb_tl_inode); >> - truncated_clusters = osb->truncated_clusters; >> - inode_unlock(osb->osb_tl_inode); >> - >> - /* >> - * Check whether we can succeed in allocating if we free >> - * the truncate log. >> - */ >> - if (truncated_clusters < needed) >> - goto out; >> - >> - ret = ocfs2_flush_truncate_log(osb); >> - if (ret) { >> - mlog_errno(ret); >> - goto out; >> - } >> - >> - if (jbd2_journal_start_commit(osb->journal->j_journal, &target)) { >> - jbd2_log_wait_commit(osb->journal->j_journal, target); >> - ret = 1; >> - } >> -out: >> - return ret; >> -} >> - >> int ocfs2_write_begin_nolock(struct address_space *mapping, >> loff_t pos, unsigned len, ocfs2_write_type_t type, >> struct page **pagep, void **fsdata, >> diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c >> index 2f19aee..9f7f3b6 100644 >> --- a/fs/ocfs2/suballoc.c >> +++ b/fs/ocfs2/suballoc.c >> @@ -1164,7 +1164,8 @@ static int ocfs2_reserve_clusters_with_limit(struct >> ocfs2_super *osb, >> int flags, >> struct ocfs2_alloc_context **ac) >> { >> - int status; >> + int status, ret = 0; >> + int retried = 0; >> >> *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL); >> if (!(*ac)) { >> @@ -1189,7 +1190,21 @@ static int ocfs2_reserve_clusters_with_limit(struct >> ocfs2_super *osb, >> } >> >> if (status == -ENOSPC) { >> +retry: >> status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac); >> + /* Retry if there is sufficient space cached in truncate log */ >> + if (status == -ENOSPC && !retried) { >> + retried = 1; >> + ocfs2_inode_unlock((*ac)->ac_inode, 1); >> + inode_unlock((*ac)->ac_inode); >> + >> + ret = ocfs2_try_to_free_truncate_log(osb, bits_wanted); >> + if (ret == 1) >> + goto retry; >> + >> + if (ret < 0) >> + mlog_errno(ret); >> + } >> if (status < 0) { >> if (status != -ENOSPC) >> mlog_errno(status); >> > > > _______________________________________________ Ocfs2-devel mailing list Ocfs2-devel@oss.oracle.com https://oss.oracle.com/mailman/listinfo/ocfs2-devel