1 files changed, 65 insertions, 21 deletions

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index eb3ac7619088..7d1860d33723 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -322,7 +322,7 @@ void nilfs_relax_pressure_in_lock(struct super_block *sb)
 	struct the_nilfs *nilfs = sb->s_fs_info;
 	struct nilfs_sc_info *sci = nilfs->ns_writer;
 
-	if (!sci || !sci->sc_flush_request)
+	if (sb_rdonly(sb) || unlikely(!sci) || !sci->sc_flush_request)
 		return;
 
 	set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
@@ -435,6 +435,23 @@ static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
 	return 0;
 }
 
+/**
+ * nilfs_segctor_zeropad_segsum - zero pad the rest of the segment summary area
+ * @sci: segment constructor object
+ *
+ * nilfs_segctor_zeropad_segsum() zero-fills unallocated space at the end of
+ * the current segment summary block.
+ */
+static void nilfs_segctor_zeropad_segsum(struct nilfs_sc_info *sci)
+{
+	struct nilfs_segsum_pointer *ssp;
+
+	ssp = sci->sc_blk_cnt > 0 ? &sci->sc_binfo_ptr : &sci->sc_finfo_ptr;
+	if (ssp->offset < ssp->bh->b_size)
+		memset(ssp->bh->b_data + ssp->offset, 0,
+		       ssp->bh->b_size - ssp->offset);
+}
+
 static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
 {
 	sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
@@ -443,6 +460,7 @@ static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
 				* The current segment is filled up
 				* (internal code)
 				*/
+	nilfs_segctor_zeropad_segsum(sci);
 	sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
 	return nilfs_segctor_reset_segment_buffer(sci);
 }
@@ -547,6 +565,7 @@ static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
 		goto retry;
 	}
 	if (unlikely(required)) {
+		nilfs_segctor_zeropad_segsum(sci);
 		err = nilfs_segbuf_extend_segsum(segbuf);
 		if (unlikely(err))
 			goto failed;
@@ -711,6 +730,11 @@ static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
 		struct page *page = pvec.pages[i];
 
 		lock_page(page);
+		if (unlikely(page->mapping != mapping)) {
+			/* Exclude pages removed from the address space */
+			unlock_page(page);
+			continue;
+		}
 		if (!page_has_buffers(page))
 			create_empty_buffers(page, i_blocksize(inode), 0);
 		unlock_page(page);
@@ -880,9 +904,11 @@ static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
 		nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
 		nilfs_cpfile_put_checkpoint(
 			nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
-	} else
-		WARN_ON(err == -EINVAL || err == -ENOENT);
-
+	} else if (err == -EINVAL || err == -ENOENT) {
+		nilfs_error(sci->sc_super,
+			    "checkpoint creation failed due to metadata corruption.");
+		err = -EIO;
+	}
 	return err;
 }
 
@@ -896,7 +922,11 @@ static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
 	err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
 					  &raw_cp, &bh_cp);
 	if (unlikely(err)) {
-		WARN_ON(err == -EINVAL || err == -ENOENT);
+		if (err == -EINVAL || err == -ENOENT) {
+			nilfs_error(sci->sc_super,
+				    "checkpoint finalization failed due to metadata corruption.");
+			err = -EIO;
+		}
 		goto failed_ibh;
 	}
 	raw_cp->cp_snapshot_list.ssl_next = 0;
@@ -959,10 +989,13 @@ static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
 	unsigned int isz, srsz;
 
 	bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root;
+
+	lock_buffer(bh_sr);
 	raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
 	isz = nilfs->ns_inode_size;
 	srsz = NILFS_SR_BYTES(isz);
 
+	raw_sr->sr_sum = 0;  /* Ensure initialization within this update */
 	raw_sr->sr_bytes = cpu_to_le16(srsz);
 	raw_sr->sr_nongc_ctime
 		= cpu_to_le64(nilfs_doing_gc() ?
@@ -976,6 +1009,8 @@ static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
 	nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
 				 NILFS_SR_SUFILE_OFFSET(isz), 1);
 	memset((void *)raw_sr + srsz, 0, nilfs->ns_blocksize - srsz);
+	set_buffer_uptodate(bh_sr);
+	unlock_buffer(bh_sr);
 }
 
 static void nilfs_redirty_inodes(struct list_head *head)
@@ -1525,6 +1560,7 @@ static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
 		nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
 		sci->sc_stage = prev_stage;
 	}
+	nilfs_segctor_zeropad_segsum(sci);
 	nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
 	return 0;
 
@@ -1666,7 +1702,6 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci)
 
 		list_for_each_entry(bh, &segbuf->sb_payload_buffers,
 				    b_assoc_buffers) {
-			set_buffer_async_write(bh);
 			if (bh == segbuf->sb_super_root) {
 				if (bh->b_page != bd_page) {
 					lock_page(bd_page);
@@ -1677,6 +1712,7 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci)
 				}
 				break;
 			}
+			set_buffer_async_write(bh);
 			if (bh->b_page != fs_page) {
 				nilfs_begin_page_io(fs_page);
 				fs_page = bh->b_page;
@@ -1752,6 +1788,7 @@ static void nilfs_abort_logs(struct list_head *logs, int err)
 	list_for_each_entry(segbuf, logs, sb_list) {
 		list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
 				    b_assoc_buffers) {
+			clear_buffer_uptodate(bh);
 			if (bh->b_page != bd_page) {
 				if (bd_page)
 					end_page_writeback(bd_page);
@@ -1761,14 +1798,15 @@ static void nilfs_abort_logs(struct list_head *logs, int err)
 
 		list_for_each_entry(bh, &segbuf->sb_payload_buffers,
 				    b_assoc_buffers) {
-			clear_buffer_async_write(bh);
 			if (bh == segbuf->sb_super_root) {
+				clear_buffer_uptodate(bh);
 				if (bh->b_page != bd_page) {
 					end_page_writeback(bd_page);
 					bd_page = bh->b_page;
 				}
 				break;
 			}
+			clear_buffer_async_write(bh);
 			if (bh->b_page != fs_page) {
 				nilfs_end_page_io(fs_page, err);
 				fs_page = bh->b_page;
@@ -1856,8 +1894,9 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
 				 BIT(BH_Delay) | BIT(BH_NILFS_Volatile) |
 				 BIT(BH_NILFS_Redirected));
 
-			set_mask_bits(&bh->b_state, clear_bits, set_bits);
 			if (bh == segbuf->sb_super_root) {
+				set_buffer_uptodate(bh);
+				clear_buffer_dirty(bh);
 				if (bh->b_page != bd_page) {
 					end_page_writeback(bd_page);
 					bd_page = bh->b_page;
@@ -1865,6 +1904,7 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
 				update_sr = true;
 				break;
 			}
+			set_mask_bits(&bh->b_state, clear_bits, set_bits);
 			if (bh->b_page != fs_page) {
 				nilfs_end_page_io(fs_page, 0);
 				fs_page = bh->b_page;
@@ -2013,6 +2053,9 @@ static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
 	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
 	int err;
 
+	if (sb_rdonly(sci->sc_super))
+		return -EROFS;
+
 	nilfs_sc_cstage_set(sci, NILFS_ST_INIT);
 	sci->sc_cno = nilfs->ns_cno;
 
@@ -2237,7 +2280,7 @@ int nilfs_construct_segment(struct super_block *sb)
 	struct nilfs_transaction_info *ti;
 	int err;
 
-	if (!sci)
+	if (sb_rdonly(sb) || unlikely(!sci))
 		return -EROFS;
 
 	/* A call inside transactions causes a deadlock. */
@@ -2276,7 +2319,7 @@ int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
 	struct nilfs_transaction_info ti;
 	int err = 0;
 
-	if (!sci)
+	if (sb_rdonly(sb) || unlikely(!sci))
 		return -EROFS;
 
 	nilfs_transaction_lock(sb, &ti, 0);
@@ -2603,11 +2646,10 @@ static int nilfs_segctor_thread(void *arg)
 	goto loop;
 
  end_thread:
-	spin_unlock(&sci->sc_state_lock);
-
 	/* end sync. */
 	sci->sc_task = NULL;
 	wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
+	spin_unlock(&sci->sc_state_lock);
 	return 0;
 }
 
@@ -2699,7 +2741,7 @@ static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
 
 		flush_work(&sci->sc_iput_work);
 
-	} while (ret && retrycount-- > 0);
+	} while (ret && ret != -EROFS && retrycount-- > 0);
 }
 
 /**
@@ -2772,11 +2814,12 @@ int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
 
 	if (nilfs->ns_writer) {
 		/*
-		 * This happens if the filesystem was remounted
-		 * read/write after nilfs_error degenerated it into a
-		 * read-only mount.
+		 * This happens if the filesystem is made read-only by
+		 * __nilfs_error or nilfs_remount and then remounted
+		 * read/write.  In these cases, reuse the existing
+		 * writer.
 		 */
-		nilfs_detach_log_writer(sb);
+		return 0;
 	}
 
 	nilfs->ns_writer = nilfs_segctor_new(sb, root);
@@ -2786,10 +2829,9 @@ int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
 	inode_attach_wb(nilfs->ns_bdev->bd_inode, NULL);
 
 	err = nilfs_segctor_start_thread(nilfs->ns_writer);
-	if (err) {
-		kfree(nilfs->ns_writer);
-		nilfs->ns_writer = NULL;
-	}
+	if (unlikely(err))
+		nilfs_detach_log_writer(sb);
+
 	return err;
 }
 
@@ -2810,6 +2852,7 @@ void nilfs_detach_log_writer(struct super_block *sb)
 		nilfs_segctor_destroy(nilfs->ns_writer);
 		nilfs->ns_writer = NULL;
 	}
+	set_nilfs_purging(nilfs);
 
 	/* Force to free the list of dirty files */
 	spin_lock(&nilfs->ns_inode_lock);
@@ -2822,4 +2865,5 @@ void nilfs_detach_log_writer(struct super_block *sb)
 	up_write(&nilfs->ns_segctor_sem);
 
 	nilfs_dispose_list(nilfs, &garbage_list, 1);
+	clear_nilfs_purging(nilfs);
 }