From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joseph Qi Date: Mon, 11 Jul 2016 19:04:45 +0800 Subject: [Ocfs2-devel] [PATCH v3] ocfs2: retry on ENOSPC if sufficient space in truncate log In-Reply-To: <1468031546-4797-1-git-send-email-zren@suse.com> References: <1468031546-4797-1-git-send-email-zren@suse.com> Message-ID: <57837D4D.2070509@huawei.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ocfs2-devel@oss.oracle.com On 2016/7/9 10:32, Eric Ren wrote: > The testcase "mmaptruncate" in ocfs2 test suite always fails with > ENOSPC error on small volume (say less than 10G). This testcase > repeatedly performs "extend" and "truncate" on a file. Continuously, > it truncates the file to 1/2 of the size, and then extends to 100% of > the 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 the right place. > > The "unlock"/"lock" code isn't elegant, but looks no better option. > > v3: > 1. Also need to lock allocator inode when "= 0" is returned from > ocfs2_schedule_truncate_log_flush(), which means no space really. > -- spotted by Joseph Qi > > v2: > 1. Lock allocator inode again if ocfs2_schedule_truncate_log_flush() > fails. -- spotted by Joseph Qi > > Signed-off-by: Eric Ren Reviewed-by: Joseph Qi > --- > fs/ocfs2/alloc.c | 37 +++++++++++++++++++++++++++++++++++++ > fs/ocfs2/alloc.h | 2 ++ > fs/ocfs2/aops.c | 37 ------------------------------------- > fs/ocfs2/suballoc.c | 20 +++++++++++++++++++- > 4 files changed, 58 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..ea47120 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 +1190,24 @@ 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); > + > + inode_lock((*ac)->ac_inode); > + ocfs2_inode_lock((*ac)->ac_inode, NULL, 1); > + } > if (status < 0) { > if (status != -ENOSPC) > mlog_errno(status); >