1 files changed, 68 insertions, 60 deletions

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 105b508b47a..69576a95e13 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -141,7 +141,7 @@ int nilfs_init_transaction_cache(void)
 }
 
 /**
- * nilfs_detroy_transaction_cache - destroy the cache for transaction info
+ * nilfs_destroy_transaction_cache - destroy the cache for transaction info
  *
  * nilfs_destroy_transaction_cache() frees the slab cache for the struct
  * nilfs_transaction_info.
@@ -201,7 +201,7 @@ static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti)
  * This function allocates a nilfs_transaction_info struct to keep context
  * information on it.  It is initialized and hooked onto the current task in
  * the outermost call.  If a pre-allocated struct is given to @ti, it is used
- * instead; othewise a new struct is assigned from a slab.
+ * instead; otherwise a new struct is assigned from a slab.
  *
  * When @vacancy_check flag is set, this function will check the amount of
  * free space, and will wait for the GC to reclaim disk space if low capacity.
@@ -1764,14 +1764,9 @@ static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci,
 static int nilfs_segctor_write(struct nilfs_sc_info *sci,
 			       struct the_nilfs *nilfs)
 {
-	struct nilfs_segment_buffer *segbuf;
-	int ret = 0;
+	int ret;
 
-	list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
-		ret = nilfs_segbuf_write(segbuf, nilfs);
-		if (ret)
-			break;
-	}
+	ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
 	list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
 	return ret;
 }
@@ -1937,8 +1932,7 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
 {
 	struct nilfs_segment_buffer *segbuf;
 	struct page *bd_page = NULL, *fs_page = NULL;
-	struct nilfs_sb_info *sbi = sci->sc_sbi;
-	struct the_nilfs *nilfs = sbi->s_nilfs;
+	struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
 	int update_sr = (sci->sc_super_root != NULL);
 
 	list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
@@ -2020,7 +2014,7 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
 	if (update_sr) {
 		nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
 				       segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
-		sbi->s_super->s_dirt = 1;
+		set_nilfs_sb_dirty(nilfs);
 
 		clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
 		clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
@@ -2220,7 +2214,7 @@ static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
 }
 
 /**
- * nilfs_secgtor_start_timer - set timer of background write
+ * nilfs_segctor_start_timer - set timer of background write
  * @sci: nilfs_sc_info
  *
  * If the timer has already been set, it ignores the new request.
@@ -2425,43 +2419,43 @@ int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
 	return err;
 }
 
-struct nilfs_segctor_req {
-	int mode;
-	__u32 seq_accepted;
-	int sc_err;  /* construction failure */
-	int sb_err;  /* super block writeback failure */
-};
-
 #define FLUSH_FILE_BIT	(0x1) /* data file only */
 #define FLUSH_DAT_BIT	(1 << NILFS_DAT_INO) /* DAT only */
 
-static void nilfs_segctor_accept(struct nilfs_sc_info *sci,
-				 struct nilfs_segctor_req *req)
+/**
+ * nilfs_segctor_accept - record accepted sequence count of log-write requests
+ * @sci: segment constructor object
+ */
+static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
 {
-	req->sc_err = req->sb_err = 0;
 	spin_lock(&sci->sc_state_lock);
-	req->seq_accepted = sci->sc_seq_request;
+	sci->sc_seq_accepted = sci->sc_seq_request;
 	spin_unlock(&sci->sc_state_lock);
 
 	if (sci->sc_timer)
 		del_timer_sync(sci->sc_timer);
 }
 
-static void nilfs_segctor_notify(struct nilfs_sc_info *sci,
-				 struct nilfs_segctor_req *req)
+/**
+ * nilfs_segctor_notify - notify the result of request to caller threads
+ * @sci: segment constructor object
+ * @mode: mode of log forming
+ * @err: error code to be notified
+ */
+static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
 {
 	/* Clear requests (even when the construction failed) */
 	spin_lock(&sci->sc_state_lock);
 
-	if (req->mode == SC_LSEG_SR) {
+	if (mode == SC_LSEG_SR) {
 		sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
-		sci->sc_seq_done = req->seq_accepted;
-		nilfs_segctor_wakeup(sci, req->sc_err ? : req->sb_err);
+		sci->sc_seq_done = sci->sc_seq_accepted;
+		nilfs_segctor_wakeup(sci, err);
 		sci->sc_flush_request = 0;
 	} else {
-		if (req->mode == SC_FLUSH_FILE)
+		if (mode == SC_FLUSH_FILE)
 			sci->sc_flush_request &= ~FLUSH_FILE_BIT;
-		else if (req->mode == SC_FLUSH_DAT)
+		else if (mode == SC_FLUSH_DAT)
 			sci->sc_flush_request &= ~FLUSH_DAT_BIT;
 
 		/* re-enable timer if checkpoint creation was not done */
@@ -2472,30 +2466,37 @@ static void nilfs_segctor_notify(struct nilfs_sc_info *sci,
 	spin_unlock(&sci->sc_state_lock);
 }
 
-static int nilfs_segctor_construct(struct nilfs_sc_info *sci,
-				   struct nilfs_segctor_req *req)
+/**
+ * nilfs_segctor_construct - form logs and write them to disk
+ * @sci: segment constructor object
+ * @mode: mode of log forming
+ */
+static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
 {
 	struct nilfs_sb_info *sbi = sci->sc_sbi;
 	struct the_nilfs *nilfs = sbi->s_nilfs;
 	int err = 0;
 
+	nilfs_segctor_accept(sci);
+
 	if (nilfs_discontinued(nilfs))
-		req->mode = SC_LSEG_SR;
-	if (!nilfs_segctor_confirm(sci)) {
-		err = nilfs_segctor_do_construct(sci, req->mode);
-		req->sc_err = err;
-	}
+		mode = SC_LSEG_SR;
+	if (!nilfs_segctor_confirm(sci))
+		err = nilfs_segctor_do_construct(sci, mode);
+
 	if (likely(!err)) {
-		if (req->mode != SC_FLUSH_DAT)
+		if (mode != SC_FLUSH_DAT)
 			atomic_set(&nilfs->ns_ndirtyblks, 0);
 		if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
 		    nilfs_discontinued(nilfs)) {
 			down_write(&nilfs->ns_sem);
-			req->sb_err = nilfs_commit_super(sbi,
-					nilfs_altsb_need_update(nilfs));
+			err = nilfs_commit_super(
+				sbi, nilfs_altsb_need_update(nilfs));
 			up_write(&nilfs->ns_sem);
 		}
 	}
+
+	nilfs_segctor_notify(sci, mode, err);
 	return err;
 }
 
@@ -2526,7 +2527,6 @@ int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
 	struct nilfs_sc_info *sci = NILFS_SC(sbi);
 	struct the_nilfs *nilfs = sbi->s_nilfs;
 	struct nilfs_transaction_info ti;
-	struct nilfs_segctor_req req = { .mode = SC_LSEG_SR };
 	int err;
 
 	if (unlikely(!sci))
@@ -2547,10 +2547,8 @@ int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
 	list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
 
 	for (;;) {
-		nilfs_segctor_accept(sci, &req);
-		err = nilfs_segctor_construct(sci, &req);
+		err = nilfs_segctor_construct(sci, SC_LSEG_SR);
 		nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
-		nilfs_segctor_notify(sci, &req);
 
 		if (likely(!err))
 			break;
@@ -2560,6 +2558,16 @@ int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
 		set_current_state(TASK_INTERRUPTIBLE);
 		schedule_timeout(sci->sc_interval);
 	}
+	if (nilfs_test_opt(sbi, DISCARD)) {
+		int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
+						 sci->sc_nfreesegs);
+		if (ret) {
+			printk(KERN_WARNING
+			       "NILFS warning: error %d on discard request, "
+			       "turning discards off for the device\n", ret);
+			nilfs_clear_opt(sbi, DISCARD);
+		}
+	}
 
  out_unlock:
 	sci->sc_freesegs = NULL;
@@ -2573,13 +2581,9 @@ static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
 {
 	struct nilfs_sb_info *sbi = sci->sc_sbi;
 	struct nilfs_transaction_info ti;
-	struct nilfs_segctor_req req = { .mode = mode };
 
 	nilfs_transaction_lock(sbi, &ti, 0);
-
-	nilfs_segctor_accept(sci, &req);
-	nilfs_segctor_construct(sci, &req);
-	nilfs_segctor_notify(sci, &req);
+	nilfs_segctor_construct(sci, mode);
 
 	/*
 	 * Unclosed segment should be retried.  We do this using sc_timer.
@@ -2635,6 +2639,7 @@ static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
 static int nilfs_segctor_thread(void *arg)
 {
 	struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
+	struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
 	struct timer_list timer;
 	int timeout = 0;
 
@@ -2680,7 +2685,6 @@ static int nilfs_segctor_thread(void *arg)
 	} else {
 		DEFINE_WAIT(wait);
 		int should_sleep = 1;
-		struct the_nilfs *nilfs;
 
 		prepare_to_wait(&sci->sc_wait_daemon, &wait,
 				TASK_INTERRUPTIBLE);
@@ -2701,8 +2705,8 @@ static int nilfs_segctor_thread(void *arg)
 		finish_wait(&sci->sc_wait_daemon, &wait);
 		timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
 			   time_after_eq(jiffies, sci->sc_timer->expires));
-		nilfs = sci->sc_sbi->s_nilfs;
-		if (sci->sc_super->s_dirt && nilfs_sb_need_update(nilfs))
+
+		if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
 			set_nilfs_discontinued(nilfs);
 	}
 	goto loop;
@@ -2797,12 +2801,9 @@ static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
 	do {
 		struct nilfs_sb_info *sbi = sci->sc_sbi;
 		struct nilfs_transaction_info ti;
-		struct nilfs_segctor_req req = { .mode = SC_LSEG_SR };
 
 		nilfs_transaction_lock(sbi, &ti, 0);
-		nilfs_segctor_accept(sci, &req);
-		ret = nilfs_segctor_construct(sci, &req);
-		nilfs_segctor_notify(sci, &req);
+		ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
 		nilfs_transaction_unlock(sbi);
 
 	} while (ret && retrycount-- > 0);
@@ -2853,7 +2854,7 @@ static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
  * @sbi: nilfs_sb_info
  *
  * nilfs_attach_segment_constructor() allocates a struct nilfs_sc_info,
- * initilizes it, and starts the segment constructor.
+ * initializes it, and starts the segment constructor.
  *
  * Return Value: On success, 0 is returned. On error, one of the following
  * negative error code is returned.
@@ -2865,8 +2866,15 @@ int nilfs_attach_segment_constructor(struct nilfs_sb_info *sbi)
 	struct the_nilfs *nilfs = sbi->s_nilfs;
 	int err;
 
-	/* Each field of nilfs_segctor is cleared through the initialization
-	   of super-block info */
+	if (NILFS_SC(sbi)) {
+		/*
+		 * This happens if the filesystem was remounted
+		 * read/write after nilfs_error degenerated it into a
+		 * read-only mount.
+		 */
+		nilfs_detach_segment_constructor(sbi);
+	}
+
 	sbi->s_sc_info = nilfs_segctor_new(sbi);
 	if (!sbi->s_sc_info)
 		return -ENOMEM;