From mboxrd@z Thu Jan 1 00:00:00 1970 From: tristan Date: Tue, 26 Oct 2010 16:28:35 +0800 Subject: [Ocfs2-devel] [PATCH] ocfs2: Try to free truncate log when meeting ENOSPC in write. In-Reply-To: <1288078148-6343-1-git-send-email-tao.ma@oracle.com> References: <1288078148-6343-1-git-send-email-tao.ma@oracle.com> Message-ID: <4CC69133.40809@oracle.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ocfs2-devel@oss.oracle.com Hi Tao, Just some tiny comments;) Tao Ma wrote: > Recently, one of our colleagues meet with a problem that if we > write/delete a 32mb files repeatly, we will get an ENOSPC in > the end. And the corresponding bug is 1288. > http://oss.oracle.com/bugzilla/show_bug.cgi?id=1288 > > The real problem is that although we have freed the clusters, > they are in truncate log and they will be summed up so that > we can free them once in a whole. > > So this patch just try to resolve it. In case we see -ENOSPC > in ocfs2_write_begin_no_lock, we will check whether the truncate > log has enough clusters for our need, if yes, we will try to > flush the truncate log at that point and try again. This method > is inspired by Mark Fasheh . Thanks. > > Cc: Mark Fasheh > Signed-off-by: Tao Ma > --- > fs/ocfs2/alloc.c | 3 ++ > fs/ocfs2/aops.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++- > fs/ocfs2/ocfs2.h | 2 + > 3 files changed, 63 insertions(+), 1 deletions(-) > > diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c > index 592fae5..8ec418d 100644 > --- a/fs/ocfs2/alloc.c > +++ b/fs/ocfs2/alloc.c > @@ -5858,6 +5858,7 @@ int ocfs2_truncate_log_append(struct ocfs2_super *osb, > > ocfs2_journal_dirty(handle, tl_bh); > > + osb->truncated_clusters += num_clusters; > bail: > mlog_exit(status); > return status; > @@ -5929,6 +5930,8 @@ static int ocfs2_replay_truncate_records(struct ocfs2_super *osb, > i--; > } > > + osb->truncated_clusters = 0; > + > bail: > mlog_exit(status); > return status; > diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c > index 5cfeee1..79adc67 100644 > --- a/fs/ocfs2/aops.c > +++ b/fs/ocfs2/aops.c > @@ -1642,6 +1642,43 @@ static int ocfs2_zero_tail(struct inode *inode, struct buffer_head *di_bh, > return ret; > } > > +/* > + * Try to flush truncate log 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) why not use 'unsigned int *needed, and return the actual cluster being freed. > +{ > + tid_t target; > + int ret = 0; > + unsigned int truncated_clusters; > + > + mutex_lock(&osb->osb_tl_inode->i_mutex); > + truncated_clusters = osb->truncated_clusters; > + mutex_unlock(&osb->osb_tl_inode->i_mutex); > + > + /* > + * 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 file *filp, > struct address_space *mapping, > loff_t pos, unsigned len, unsigned flags, > @@ -1649,7 +1686,7 @@ int ocfs2_write_begin_nolock(struct file *filp, > struct buffer_head *di_bh, struct page *mmap_page) > { > int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS; > - unsigned int clusters_to_alloc, extents_to_split; > + unsigned int clusters_to_alloc, extents_to_split, clusters_need = 0; > struct ocfs2_write_ctxt *wc; > struct inode *inode = mapping->host; > struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); > @@ -1658,7 +1695,9 @@ int ocfs2_write_begin_nolock(struct file *filp, > struct ocfs2_alloc_context *meta_ac = NULL; > handle_t *handle; > struct ocfs2_extent_tree et; > + int try_free = 0, ret1; > > +try_again: > ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, di_bh); > if (ret) { > mlog_errno(ret); > @@ -1693,6 +1732,7 @@ int ocfs2_write_begin_nolock(struct file *filp, > mlog_errno(ret); > goto out; > } else if (ret == 1) { > + clusters_need = wc->w_clen; > ret = ocfs2_refcount_cow(inode, filp, di_bh, > wc->w_cpos, wc->w_clen, UINT_MAX); > if (ret) { > @@ -1707,6 +1747,7 @@ int ocfs2_write_begin_nolock(struct file *filp, > mlog_errno(ret); > goto out; > } > + clusters_need += clusters_to_alloc; > > di = (struct ocfs2_dinode *)wc->w_di_bh->b_data; > > @@ -1829,6 +1870,22 @@ out: > ocfs2_free_alloc_context(data_ac); > if (meta_ac) > ocfs2_free_alloc_context(meta_ac); > + > + if (ret == -ENOSPC && !try_free) { Literally, if (ret == -ENOSPC && try_free) make more sense here for a better readability;-) You can set the try_free with a fixed value at the very beginning, which in other words, means set the retry times we're allowing to perform after the allocation failure. > + /* > + * Try to free some truncate log so that we can have enough > + * clusters to allocate. > + */ > + try_free = 1; try_free--; > + > + ret1 = ocfs2_try_to_free_truncate_log(osb, clusters_need); > + if (ret1 == 1) > + goto try_again; > + > + if (ret1 < 0) > + mlog_errno(ret1); > + } > + > return ret; > } > > diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h > index d840821..de06558 100644 > --- a/fs/ocfs2/ocfs2.h > +++ b/fs/ocfs2/ocfs2.h > @@ -439,6 +439,8 @@ struct ocfs2_super > /* rb tree root for refcount lock. */ > struct rb_root osb_rf_lock_tree; > struct ocfs2_refcount_tree *osb_ref_tree_lru; > + > + unsigned int truncated_clusters; > }; > > #define OCFS2_SB(sb) ((struct ocfs2_super *)(sb)->s_fs_info)