4 files changed, 165 insertions, 95 deletions

diff --git a/fs/nilfs2/segbuf.c b/fs/nilfs2/segbuf.c
index d856d62..645c786 100644
--- a/fs/nilfs2/segbuf.c
+++ b/fs/nilfs2/segbuf.c
@@ -100,6 +100,22 @@ void nilfs_segbuf_map(struct nilfs_segment_buffer *segbuf, __u64 segnum,
 		segbuf->sb_fseg_end - segbuf->sb_pseg_start + 1;
 }
 
+/**
+ * nilfs_segbuf_map_cont - map a new log behind a given log
+ * @segbuf: new segment buffer
+ * @prev: segment buffer containing a log to be continued
+ */
+void nilfs_segbuf_map_cont(struct nilfs_segment_buffer *segbuf,
+			   struct nilfs_segment_buffer *prev)
+{
+	segbuf->sb_segnum = prev->sb_segnum;
+	segbuf->sb_fseg_start = prev->sb_fseg_start;
+	segbuf->sb_fseg_end = prev->sb_fseg_end;
+	segbuf->sb_pseg_start = prev->sb_pseg_start + prev->sb_sum.nblocks;
+	segbuf->sb_rest_blocks =
+		segbuf->sb_fseg_end - segbuf->sb_pseg_start + 1;
+}
+
 void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *segbuf,
 				  __u64 nextnum, struct the_nilfs *nilfs)
 {
diff --git a/fs/nilfs2/segbuf.h b/fs/nilfs2/segbuf.h
index 7fbaf5e..6af1630 100644
--- a/fs/nilfs2/segbuf.h
+++ b/fs/nilfs2/segbuf.h
@@ -128,6 +128,8 @@ struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *);
 void nilfs_segbuf_free(struct nilfs_segment_buffer *);
 void nilfs_segbuf_map(struct nilfs_segment_buffer *, __u64, unsigned long,
 		      struct the_nilfs *);
+void nilfs_segbuf_map_cont(struct nilfs_segment_buffer *segbuf,
+			   struct nilfs_segment_buffer *prev);
 void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *, __u64,
 				  struct the_nilfs *);
 int nilfs_segbuf_reset(struct nilfs_segment_buffer *, unsigned, time_t);
diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 689deb9..17584c5 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -1273,48 +1273,69 @@ static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
 	return err;
 }
 
+/**
+ * nilfs_segctor_begin_construction - setup segment buffer to make a new log
+ * @sci: nilfs_sc_info
+ * @nilfs: nilfs object
+ */
 static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
 					    struct the_nilfs *nilfs)
 {
-	struct nilfs_segment_buffer *segbuf;
+	struct nilfs_segment_buffer *segbuf, *prev;
 	__u64 nextnum;
-	int err;
+	int err, alloc = 0;
 
-	if (list_empty(&sci->sc_segbufs)) {
-		segbuf = nilfs_segbuf_new(sci->sc_super);
-		if (unlikely(!segbuf))
-			return -ENOMEM;
-		list_add(&segbuf->sb_list, &sci->sc_segbufs);
-	} else
-		segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
+	segbuf = nilfs_segbuf_new(sci->sc_super);
+	if (unlikely(!segbuf))
+		return -ENOMEM;
 
-	nilfs_segbuf_map(segbuf, nilfs->ns_segnum, nilfs->ns_pseg_offset,
-			 nilfs);
+	if (list_empty(&sci->sc_write_logs)) {
+		nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
+				 nilfs->ns_pseg_offset, nilfs);
+		if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
+			nilfs_shift_to_next_segment(nilfs);
+			nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
+		}
 
-	if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
-		nilfs_shift_to_next_segment(nilfs);
-		nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
+		segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
+		nextnum = nilfs->ns_nextnum;
+
+		if (nilfs->ns_segnum == nilfs->ns_nextnum)
+			/* Start from the head of a new full segment */
+			alloc++;
+	} else {
+		/* Continue logs */
+		prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
+		nilfs_segbuf_map_cont(segbuf, prev);
+		segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
+		nextnum = prev->sb_nextnum;
+
+		if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
+			nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
+			segbuf->sb_sum.seg_seq++;
+			alloc++;
+		}
 	}
-	sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
 
 	err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
-	if (unlikely(err))
-		return err;
+	if (err)
+		goto failed;
 
-	if (nilfs->ns_segnum == nilfs->ns_nextnum) {
-		/* Start from the head of a new full segment */
+	if (alloc) {
 		err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
-		if (unlikely(err))
-			return err;
-	} else
-		nextnum = nilfs->ns_nextnum;
-
-	segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
+		if (err)
+			goto failed;
+	}
 	nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
 
-	/* truncating segment buffers */
-	nilfs_truncate_logs(&sci->sc_segbufs, segbuf);
+	BUG_ON(!list_empty(&sci->sc_segbufs));
+	list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
+	sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
 	return 0;
+
+ failed:
+	nilfs_segbuf_free(segbuf);
+	return err;
 }
 
 static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
@@ -1373,15 +1394,16 @@ static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
 	return err;
 }
 
-static void nilfs_segctor_free_incomplete_segments(struct nilfs_sc_info *sci,
-						   struct the_nilfs *nilfs)
+static void nilfs_free_incomplete_logs(struct list_head *logs,
+				       struct the_nilfs *nilfs)
 {
-	struct nilfs_segment_buffer *segbuf;
+	struct nilfs_segment_buffer *segbuf, *prev;
+	struct inode *sufile = nilfs->ns_sufile;
 	int ret;
 
-	segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
+	segbuf = NILFS_FIRST_SEGBUF(logs);
 	if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
-		ret = nilfs_sufile_free(nilfs->ns_sufile, segbuf->sb_nextnum);
+		ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
 		WARN_ON(ret); /* never fails */
 	}
 	if (atomic_read(&segbuf->sb_err)) {
@@ -1395,34 +1417,18 @@ static void nilfs_segctor_free_incomplete_segments(struct nilfs_sc_info *sci,
 			set_nilfs_discontinued(nilfs);
 	}
 
-	list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
-		ret = nilfs_sufile_free(nilfs->ns_sufile, segbuf->sb_nextnum);
-		WARN_ON(ret); /* never fails */
+	prev = segbuf;
+	list_for_each_entry_continue(segbuf, logs, sb_list) {
+		if (prev->sb_nextnum != segbuf->sb_nextnum) {
+			ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
+			WARN_ON(ret); /* never fails */
+		}
 		if (atomic_read(&segbuf->sb_err) &&
 		    segbuf->sb_segnum != nilfs->ns_nextnum)
 			/* Case 2: extended segment (!= next) failed */
-			nilfs_sufile_set_error(nilfs->ns_sufile,
-					       segbuf->sb_segnum);
-	}
-}
-
-static void nilfs_segctor_end_construction(struct nilfs_sc_info *sci,
-					   struct the_nilfs *nilfs, int err)
-{
-	if (unlikely(err)) {
-		nilfs_segctor_free_incomplete_segments(sci, nilfs);
-		if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
-			int ret;
-
-			ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
-							sci->sc_freesegs,
-							sci->sc_nfreesegs,
-							NULL);
-			WARN_ON(ret); /* do not happen */
-		}
+			nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
+		prev = segbuf;
 	}
-	nilfs_clear_logs(&sci->sc_segbufs);
-	sci->sc_super_root = NULL;
 }
 
 static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
@@ -1442,19 +1448,18 @@ static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
 	}
 }
 
-static void nilfs_segctor_cancel_segusage(struct nilfs_sc_info *sci,
-					  struct inode *sufile)
+static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
 {
 	struct nilfs_segment_buffer *segbuf;
 	int ret;
 
-	segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
+	segbuf = NILFS_FIRST_SEGBUF(logs);
 	ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
 					     segbuf->sb_pseg_start -
 					     segbuf->sb_fseg_start, 0);
 	WARN_ON(ret); /* always succeed because the segusage is dirty */
 
-	list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
+	list_for_each_entry_continue(segbuf, logs, sb_list) {
 		ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
 						     0, 0);
 		WARN_ON(ret); /* always succeed */
@@ -1760,17 +1765,15 @@ static int nilfs_segctor_write(struct nilfs_sc_info *sci,
 			       struct the_nilfs *nilfs)
 {
 	struct nilfs_segment_buffer *segbuf;
-	int err, res;
+	int ret = 0;
 
 	list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
-		err = nilfs_segbuf_write(segbuf, nilfs);
-
-		res = nilfs_segbuf_wait(segbuf);
-		err = err ? : res;
-		if (err)
-			return err;
+		ret = nilfs_segbuf_write(segbuf, nilfs);
+		if (ret)
+			break;
 	}
-	return 0;
+	list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
+	return ret;
 }
 
 static void __nilfs_end_page_io(struct page *page, int err)
@@ -1848,15 +1851,17 @@ static void nilfs_clear_copied_buffers(struct list_head *list, int err)
 	}
 }
 
-static void nilfs_segctor_abort_write(struct nilfs_sc_info *sci,
-				      struct page *failed_page, int err)
+static void nilfs_abort_logs(struct list_head *logs, struct page *failed_page,
+			     struct buffer_head *bh_sr, int err)
 {
 	struct nilfs_segment_buffer *segbuf;
 	struct page *bd_page = NULL, *fs_page = NULL;
+	struct buffer_head *bh;
 
-	list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
-		struct buffer_head *bh;
+	if (list_empty(logs))
+		return;
 
+	list_for_each_entry(segbuf, logs, sb_list) {
 		list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
 				    b_assoc_buffers) {
 			if (bh->b_page != bd_page) {
@@ -1868,7 +1873,7 @@ static void nilfs_segctor_abort_write(struct nilfs_sc_info *sci,
 
 		list_for_each_entry(bh, &segbuf->sb_payload_buffers,
 				    b_assoc_buffers) {
-			if (bh == sci->sc_super_root) {
+			if (bh == bh_sr) {
 				if (bh->b_page != bd_page) {
 					end_page_writeback(bd_page);
 					bd_page = bh->b_page;
@@ -1878,7 +1883,7 @@ static void nilfs_segctor_abort_write(struct nilfs_sc_info *sci,
 			if (bh->b_page != fs_page) {
 				nilfs_end_page_io(fs_page, err);
 				if (fs_page && fs_page == failed_page)
-					goto done;
+					return;
 				fs_page = bh->b_page;
 			}
 		}
@@ -1887,8 +1892,34 @@ static void nilfs_segctor_abort_write(struct nilfs_sc_info *sci,
 		end_page_writeback(bd_page);
 
 	nilfs_end_page_io(fs_page, err);
- done:
+}
+
+static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
+					     struct the_nilfs *nilfs, int err)
+{
+	LIST_HEAD(logs);
+	int ret;
+
+	list_splice_tail_init(&sci->sc_write_logs, &logs);
+	ret = nilfs_wait_on_logs(&logs);
+	if (ret)
+		nilfs_abort_logs(&logs, NULL, sci->sc_super_root, ret);
+
+	list_splice_tail_init(&sci->sc_segbufs, &logs);
+	nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
+	nilfs_free_incomplete_logs(&logs, nilfs);
 	nilfs_clear_copied_buffers(&sci->sc_copied_buffers, err);
+
+	if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
+		ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
+						sci->sc_freesegs,
+						sci->sc_nfreesegs,
+						NULL);
+		WARN_ON(ret); /* do not happen */
+	}
+
+	nilfs_destroy_logs(&logs);
+	sci->sc_super_root = NULL;
 }
 
 static void nilfs_set_next_segment(struct the_nilfs *nilfs,
@@ -1910,7 +1941,7 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
 	struct the_nilfs *nilfs = sbi->s_nilfs;
 	int update_sr = (sci->sc_super_root != NULL);
 
-	list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
+	list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
 		struct buffer_head *bh;
 
 		list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
@@ -1983,7 +2014,7 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
 
 	sci->sc_nblk_inc += sci->sc_nblk_this_inc;
 
-	segbuf = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
+	segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
 	nilfs_set_next_segment(nilfs, segbuf);
 
 	if (update_sr) {
@@ -1994,10 +2025,23 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
 		clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
 		clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
 		set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
+		nilfs_segctor_clear_metadata_dirty(sci);
 	} else
 		clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
 }
 
+static int nilfs_segctor_wait(struct nilfs_sc_info *sci)
+{
+	int ret;
+
+	ret = nilfs_wait_on_logs(&sci->sc_write_logs);
+	if (!ret) {
+		nilfs_segctor_complete_write(sci);
+		nilfs_destroy_logs(&sci->sc_write_logs);
+	}
+	return ret;
+}
+
 static int nilfs_segctor_check_in_files(struct nilfs_sc_info *sci,
 					struct nilfs_sb_info *sbi)
 {
@@ -2110,7 +2154,7 @@ static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
 		/* Avoid empty segment */
 		if (sci->sc_stage.scnt == NILFS_ST_DONE &&
 		    NILFS_SEG_EMPTY(&sci->sc_curseg->sb_sum)) {
-			nilfs_segctor_end_construction(sci, nilfs, 1);
+			nilfs_segctor_abort_construction(sci, nilfs, 1);
 			goto out;
 		}
 
@@ -2124,7 +2168,7 @@ static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
 		if (has_sr) {
 			err = nilfs_segctor_fill_in_checkpoint(sci);
 			if (unlikely(err))
-				goto failed_to_make_up;
+				goto failed_to_write;
 
 			nilfs_segctor_fill_in_super_root(sci, nilfs);
 		}
@@ -2132,42 +2176,46 @@ static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
 
 		/* Write partial segments */
 		err = nilfs_segctor_prepare_write(sci, &failed_page);
-		if (unlikely(err))
+		if (err) {
+			nilfs_abort_logs(&sci->sc_segbufs, failed_page,
+					 sci->sc_super_root, err);
 			goto failed_to_write;
-
+		}
 		nilfs_segctor_fill_in_checksums(sci, nilfs->ns_crc_seed);
 
 		err = nilfs_segctor_write(sci, nilfs);
 		if (unlikely(err))
 			goto failed_to_write;
 
-		nilfs_segctor_complete_write(sci);
-
-		/* Commit segments */
-		if (has_sr)
-			nilfs_segctor_clear_metadata_dirty(sci);
-
-		nilfs_segctor_end_construction(sci, nilfs, 0);
-
+		if (sci->sc_stage.scnt == NILFS_ST_DONE ||
+		    nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) {
+			/*
+			 * At this point, we avoid double buffering
+			 * for blocksize < pagesize because page dirty
+			 * flag is turned off during write and dirty
+			 * buffers are not properly collected for
+			 * pages crossing over segments.
+			 */
+			err = nilfs_segctor_wait(sci);
+			if (err)
+				goto failed_to_write;
+		}
 	} while (sci->sc_stage.scnt != NILFS_ST_DONE);
 
+	sci->sc_super_root = NULL;
+
  out:
-	nilfs_destroy_logs(&sci->sc_segbufs);
 	nilfs_segctor_check_out_files(sci, sbi);
 	return err;
 
  failed_to_write:
-	nilfs_segctor_abort_write(sci, failed_page, err);
-	nilfs_segctor_cancel_segusage(sci, nilfs->ns_sufile);
-
- failed_to_make_up:
 	if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
 		nilfs_redirty_inodes(&sci->sc_dirty_files);
 
  failed:
 	if (nilfs_doing_gc())
 		nilfs_redirty_inodes(&sci->sc_gc_inodes);
-	nilfs_segctor_end_construction(sci, nilfs, err);
+	nilfs_segctor_abort_construction(sci, nilfs, err);
 	goto out;
 }
 
@@ -2725,6 +2773,7 @@ static struct nilfs_sc_info *nilfs_segctor_new(struct nilfs_sb_info *sbi)
 	spin_lock_init(&sci->sc_state_lock);
 	INIT_LIST_HEAD(&sci->sc_dirty_files);
 	INIT_LIST_HEAD(&sci->sc_segbufs);
+	INIT_LIST_HEAD(&sci->sc_write_logs);
 	INIT_LIST_HEAD(&sci->sc_gc_inodes);
 	INIT_LIST_HEAD(&sci->sc_copied_buffers);
 
@@ -2792,6 +2841,7 @@ static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
 	}
 
 	WARN_ON(!list_empty(&sci->sc_segbufs));
+	WARN_ON(!list_empty(&sci->sc_write_logs));
 
 	down_write(&sbi->s_nilfs->ns_segctor_sem);
 
diff --git a/fs/nilfs2/segment.h b/fs/nilfs2/segment.h
index 0d2a475..3d3ab2f 100644
--- a/fs/nilfs2/segment.h
+++ b/fs/nilfs2/segment.h
@@ -97,6 +97,7 @@ struct nilfs_segsum_pointer {
  * @sc_dsync_start: start byte offset of data pages
  * @sc_dsync_end: end byte offset of data pages (inclusive)
  * @sc_segbufs: List of segment buffers
+ * @sc_write_logs: List of segment buffers to hold logs under writing
  * @sc_segbuf_nblocks: Number of available blocks in segment buffers.
  * @sc_curseg: Current segment buffer
  * @sc_super_root: Pointer to the super root buffer
@@ -143,6 +144,7 @@ struct nilfs_sc_info {
 
 	/* Segment buffers */
 	struct list_head	sc_segbufs;
+	struct list_head	sc_write_logs;
 	unsigned long		sc_segbuf_nblocks;
 	struct nilfs_segment_buffer *sc_curseg;
 	struct buffer_head     *sc_super_root;