Merge tag 'f2fs-for-3.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

Pull f2fs fixes from Jaegeuk Kim:
 o Support swap file and link generic_file_remap_pages
 o Enhance the bio streaming flow and free section control
 o Major bug fix on recovery routine
 o Minor bug/warning fixes and code cleanups

* tag 'f2fs-for-3.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (22 commits)
  f2fs: use _safe() version of list_for_each
  f2fs: add comments of start_bidx_of_node
  f2fs: avoid issuing small bios due to several dirty node pages
  f2fs: support swapfile
  f2fs: add remap_pages as generic_file_remap_pages
  f2fs: add __init to functions in init_f2fs_fs
  f2fs: fix the debugfs entry creation path
  f2fs: add global mutex_lock to protect f2fs_stat_list
  f2fs: remove the blk_plug usage in f2fs_write_data_pages
  f2fs: avoid redundant time update for parent directory in f2fs_delete_entry
  f2fs: remove redundant call to set_blocksize in f2fs_fill_super
  f2fs: move f2fs_balance_fs to punch_hole
  f2fs: add f2fs_balance_fs in several interfaces
  f2fs: revisit the f2fs_gc flow
  f2fs: check return value during recovery
  f2fs: avoid null dereference in f2fs_acl_from_disk
  f2fs: initialize newly allocated dnode structure
  f2fs: update f2fs partition info about SIT/NAT layout
  f2fs: update f2fs document to reflect SIT/NAT layout correctly
  f2fs: remove unneeded INIT_LIST_HEAD at few places
  ...

14 files changed, 189 insertions, 131 deletions

diff --git a/fs/f2fs/acl.c b/fs/f2fs/acl.c
index e95b94945d5..137af4255da 100644
--- a/fs/f2fs/acl.c
+++ b/fs/f2fs/acl.c
@@ -191,15 +191,14 @@ struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
 		retval = f2fs_getxattr(inode, name_index, "", value, retval);
 	}
 
-	if (retval < 0) {
-		if (retval == -ENODATA)
-			acl = NULL;
-		else
-			acl = ERR_PTR(retval);
-	} else {
+	if (retval > 0)
 		acl = f2fs_acl_from_disk(value, retval);
-	}
+	else if (retval == -ENODATA)
+		acl = NULL;
+	else
+		acl = ERR_PTR(retval);
 	kfree(value);
+
 	if (!IS_ERR(acl))
 		set_cached_acl(inode, type, acl);
 
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 6ef36c37e2b..ff3c8439af8 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -214,7 +214,6 @@ retry:
 		goto retry;
 	}
 	new->ino = ino;
-	INIT_LIST_HEAD(&new->list);
 
 	/* add new_oentry into list which is sorted by inode number */
 	if (orphan) {
@@ -772,7 +771,7 @@ void init_orphan_info(struct f2fs_sb_info *sbi)
 	sbi->n_orphans = 0;
 }
 
-int create_checkpoint_caches(void)
+int __init create_checkpoint_caches(void)
 {
 	orphan_entry_slab = f2fs_kmem_cache_create("f2fs_orphan_entry",
 			sizeof(struct orphan_inode_entry), NULL);
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 3aa5ce7cab8..7bd22a20112 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -547,6 +547,15 @@ redirty_out:
 
 #define MAX_DESIRED_PAGES_WP	4096
 
+static int __f2fs_writepage(struct page *page, struct writeback_control *wbc,
+			void *data)
+{
+	struct address_space *mapping = data;
+	int ret = mapping->a_ops->writepage(page, wbc);
+	mapping_set_error(mapping, ret);
+	return ret;
+}
+
 static int f2fs_write_data_pages(struct address_space *mapping,
 			    struct writeback_control *wbc)
 {
@@ -563,7 +572,7 @@ static int f2fs_write_data_pages(struct address_space *mapping,
 
 	if (!S_ISDIR(inode->i_mode))
 		mutex_lock(&sbi->writepages);
-	ret = generic_writepages(mapping, wbc);
+	ret = write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
 	if (!S_ISDIR(inode->i_mode))
 		mutex_unlock(&sbi->writepages);
 	f2fs_submit_bio(sbi, DATA, (wbc->sync_mode == WB_SYNC_ALL));
@@ -689,6 +698,11 @@ static int f2fs_set_data_page_dirty(struct page *page)
 	return 0;
 }
 
+static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
+{
+	return generic_block_bmap(mapping, block, get_data_block_ro);
+}
+
 const struct address_space_operations f2fs_dblock_aops = {
 	.readpage	= f2fs_read_data_page,
 	.readpages	= f2fs_read_data_pages,
@@ -700,4 +714,5 @@ const struct address_space_operations f2fs_dblock_aops = {
 	.invalidatepage	= f2fs_invalidate_data_page,
 	.releasepage	= f2fs_release_data_page,
 	.direct_IO	= f2fs_direct_IO,
+	.bmap		= f2fs_bmap,
 };
diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index 0e0380a588a..c8c37307b32 100644
--- a/fs/f2fs/debug.c
+++ b/fs/f2fs/debug.c
@@ -26,6 +26,7 @@
 
 static LIST_HEAD(f2fs_stat_list);
 static struct dentry *debugfs_root;
+static DEFINE_MUTEX(f2fs_stat_mutex);
 
 static void update_general_status(struct f2fs_sb_info *sbi)
 {
@@ -180,18 +181,14 @@ static int stat_show(struct seq_file *s, void *v)
 	int i = 0;
 	int j;
 
+	mutex_lock(&f2fs_stat_mutex);
 	list_for_each_entry_safe(si, next, &f2fs_stat_list, stat_list) {
 
-		mutex_lock(&si->stat_lock);
-		if (!si->sbi) {
-			mutex_unlock(&si->stat_lock);
-			continue;
-		}
 		update_general_status(si->sbi);
 
 		seq_printf(s, "\n=====[ partition info. #%d ]=====\n", i++);
-		seq_printf(s, "[SB: 1] [CP: 2] [NAT: %d] [SIT: %d] ",
-			   si->nat_area_segs, si->sit_area_segs);
+		seq_printf(s, "[SB: 1] [CP: 2] [SIT: %d] [NAT: %d] ",
+			   si->sit_area_segs, si->nat_area_segs);
 		seq_printf(s, "[SSA: %d] [MAIN: %d",
 			   si->ssa_area_segs, si->main_area_segs);
 		seq_printf(s, "(OverProv:%d Resv:%d)]\n\n",
@@ -286,8 +283,8 @@ static int stat_show(struct seq_file *s, void *v)
 		seq_printf(s, "\nMemory: %u KB = static: %u + cached: %u\n",
 				(si->base_mem + si->cache_mem) >> 10,
 				si->base_mem >> 10, si->cache_mem >> 10);
-		mutex_unlock(&si->stat_lock);
 	}
+	mutex_unlock(&f2fs_stat_mutex);
 	return 0;
 }
 
@@ -303,7 +300,7 @@ static const struct file_operations stat_fops = {
 	.release = single_release,
 };
 
-static int init_stats(struct f2fs_sb_info *sbi)
+int f2fs_build_stats(struct f2fs_sb_info *sbi)
 {
 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
 	struct f2fs_stat_info *si;
@@ -313,9 +310,6 @@ static int init_stats(struct f2fs_sb_info *sbi)
 		return -ENOMEM;
 
 	si = sbi->stat_info;
-	mutex_init(&si->stat_lock);
-	list_add_tail(&si->stat_list, &f2fs_stat_list);
-
 	si->all_area_segs = le32_to_cpu(raw_super->segment_count);
 	si->sit_area_segs = le32_to_cpu(raw_super->segment_count_sit);
 	si->nat_area_segs = le32_to_cpu(raw_super->segment_count_nat);
@@ -325,21 +319,11 @@ static int init_stats(struct f2fs_sb_info *sbi)
 	si->main_area_zones = si->main_area_sections /
 				le32_to_cpu(raw_super->secs_per_zone);
 	si->sbi = sbi;
-	return 0;
-}
 
-int f2fs_build_stats(struct f2fs_sb_info *sbi)
-{
-	int retval;
-
-	retval = init_stats(sbi);
-	if (retval)
-		return retval;
-
-	if (!debugfs_root)
-		debugfs_root = debugfs_create_dir("f2fs", NULL);
+	mutex_lock(&f2fs_stat_mutex);
+	list_add_tail(&si->stat_list, &f2fs_stat_list);
+	mutex_unlock(&f2fs_stat_mutex);
 
-	debugfs_create_file("status", S_IRUGO, debugfs_root, NULL, &stat_fops);
 	return 0;
 }
 
@@ -347,14 +331,22 @@ void f2fs_destroy_stats(struct f2fs_sb_info *sbi)
 {
 	struct f2fs_stat_info *si = sbi->stat_info;
 
+	mutex_lock(&f2fs_stat_mutex);
 	list_del(&si->stat_list);
-	mutex_lock(&si->stat_lock);
-	si->sbi = NULL;
-	mutex_unlock(&si->stat_lock);
+	mutex_unlock(&f2fs_stat_mutex);
+
 	kfree(sbi->stat_info);
 }
 
-void destroy_root_stats(void)
+void __init f2fs_create_root_stats(void)
+{
+	debugfs_root = debugfs_create_dir("f2fs", NULL);
+	if (debugfs_root)
+		debugfs_create_file("status", S_IRUGO, debugfs_root,
+					 NULL, &stat_fops);
+}
+
+void f2fs_destroy_root_stats(void)
 {
 	debugfs_remove_recursive(debugfs_root);
 	debugfs_root = NULL;
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 951ed52748f..989980e16d0 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -503,7 +503,7 @@ void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
 	}
 
 	if (inode) {
-		inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+		inode->i_ctime = CURRENT_TIME;
 		drop_nlink(inode);
 		if (S_ISDIR(inode->i_mode)) {
 			drop_nlink(inode);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 13c6dfbb718..c8e2d751ef9 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -211,11 +211,11 @@ struct dnode_of_data {
 static inline void set_new_dnode(struct dnode_of_data *dn, struct inode *inode,
 		struct page *ipage, struct page *npage, nid_t nid)
 {
+	memset(dn, 0, sizeof(*dn));
 	dn->inode = inode;
 	dn->inode_page = ipage;
 	dn->node_page = npage;
 	dn->nid = nid;
-	dn->inode_page_locked = 0;
 }
 
 /*
@@ -877,6 +877,8 @@ bool f2fs_empty_dir(struct inode *);
  * super.c
  */
 int f2fs_sync_fs(struct super_block *, int);
+extern __printf(3, 4)
+void f2fs_msg(struct super_block *, const char *, const char *, ...);
 
 /*
  * hash.c
@@ -912,7 +914,7 @@ int restore_node_summary(struct f2fs_sb_info *, unsigned int,
 void flush_nat_entries(struct f2fs_sb_info *);
 int build_node_manager(struct f2fs_sb_info *);
 void destroy_node_manager(struct f2fs_sb_info *);
-int create_node_manager_caches(void);
+int __init create_node_manager_caches(void);
 void destroy_node_manager_caches(void);
 
 /*
@@ -964,7 +966,7 @@ void sync_dirty_dir_inodes(struct f2fs_sb_info *);
 void block_operations(struct f2fs_sb_info *);
 void write_checkpoint(struct f2fs_sb_info *, bool, bool);
 void init_orphan_info(struct f2fs_sb_info *);
-int create_checkpoint_caches(void);
+int __init create_checkpoint_caches(void);
 void destroy_checkpoint_caches(void);
 
 /*
@@ -984,9 +986,9 @@ int do_write_data_page(struct page *);
 int start_gc_thread(struct f2fs_sb_info *);
 void stop_gc_thread(struct f2fs_sb_info *);
 block_t start_bidx_of_node(unsigned int);
-int f2fs_gc(struct f2fs_sb_info *, int);
+int f2fs_gc(struct f2fs_sb_info *);
 void build_gc_manager(struct f2fs_sb_info *);
-int create_gc_caches(void);
+int __init create_gc_caches(void);
 void destroy_gc_caches(void);
 
 /*
@@ -1058,7 +1060,8 @@ struct f2fs_stat_info {
 
 int f2fs_build_stats(struct f2fs_sb_info *);
 void f2fs_destroy_stats(struct f2fs_sb_info *);
-void destroy_root_stats(void);
+void __init f2fs_create_root_stats(void);
+void f2fs_destroy_root_stats(void);
 #else
 #define stat_inc_call_count(si)
 #define stat_inc_seg_count(si, type)
@@ -1068,7 +1071,8 @@ void destroy_root_stats(void);
 
 static inline int f2fs_build_stats(struct f2fs_sb_info *sbi) { return 0; }
 static inline void f2fs_destroy_stats(struct f2fs_sb_info *sbi) { }
-static inline void destroy_root_stats(void) { }
+static inline void __init f2fs_create_root_stats(void) { }
+static inline void f2fs_destroy_root_stats(void) { }
 #endif
 
 extern const struct file_operations f2fs_dir_operations;
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 7f9ea9271eb..3191b52aafb 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -96,8 +96,9 @@ out:
 }
 
 static const struct vm_operations_struct f2fs_file_vm_ops = {
-	.fault        = filemap_fault,
-	.page_mkwrite = f2fs_vm_page_mkwrite,
+	.fault		= filemap_fault,
+	.page_mkwrite	= f2fs_vm_page_mkwrite,
+	.remap_pages	= generic_file_remap_pages,
 };
 
 static int need_to_sync_dir(struct f2fs_sb_info *sbi, struct inode *inode)
@@ -137,6 +138,9 @@ int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 	if (ret)
 		return ret;
 
+	/* guarantee free sections for fsync */
+	f2fs_balance_fs(sbi);
+
 	mutex_lock(&inode->i_mutex);
 
 	if (datasync && !(inode->i_state & I_DIRTY_DATASYNC))
@@ -407,6 +411,8 @@ int truncate_hole(struct inode *inode, pgoff_t pg_start, pgoff_t pg_end)
 		struct dnode_of_data dn;
 		struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 
+		f2fs_balance_fs(sbi);
+
 		mutex_lock_op(sbi, DATA_TRUNC);
 		set_new_dnode(&dn, inode, NULL, NULL, 0);
 		err = get_dnode_of_data(&dn, index, RDONLY_NODE);
@@ -534,7 +540,6 @@ static long f2fs_fallocate(struct file *file, int mode,
 				loff_t offset, loff_t len)
 {
 	struct inode *inode = file->f_path.dentry->d_inode;
-	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	long ret;
 
 	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
@@ -545,7 +550,10 @@ static long f2fs_fallocate(struct file *file, int mode,
 	else
 		ret = expand_inode_data(inode, offset, len, mode);
 
-	f2fs_balance_fs(sbi);
+	if (!ret) {
+		inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+		mark_inode_dirty(inode);
+	}
 	return ret;
 }
 
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index b0ec721e984..c386910dacc 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -78,7 +78,7 @@ static int gc_thread_func(void *data)
 
 		sbi->bg_gc++;
 
-		if (f2fs_gc(sbi, 1) == GC_NONE)
+		if (f2fs_gc(sbi) == GC_NONE)
 			wait_ms = GC_THREAD_NOGC_SLEEP_TIME;
 		else if (wait_ms == GC_THREAD_NOGC_SLEEP_TIME)
 			wait_ms = GC_THREAD_MAX_SLEEP_TIME;
@@ -424,7 +424,11 @@ next_step:
 }
 
 /*
- * Calculate start block index that this node page contains
+ * Calculate start block index indicating the given node offset.
+ * Be careful, caller should give this node offset only indicating direct node
+ * blocks. If any node offsets, which point the other types of node blocks such
+ * as indirect or double indirect node blocks, are given, it must be a caller's
+ * bug.
  */
 block_t start_bidx_of_node(unsigned int node_ofs)
 {
@@ -651,62 +655,44 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno,
 	return ret;
 }
 
-int f2fs_gc(struct f2fs_sb_info *sbi, int nGC)
+int f2fs_gc(struct f2fs_sb_info *sbi)
 {
-	unsigned int segno;
-	int old_free_secs, cur_free_secs;
-	int gc_status, nfree;
 	struct list_head ilist;
+	unsigned int segno, i;
 	int gc_type = BG_GC;
+	int gc_status = GC_NONE;
 
 	INIT_LIST_HEAD(&ilist);
 gc_more:
-	nfree = 0;
-	gc_status = GC_NONE;
+	if (!(sbi->sb->s_flags & MS_ACTIVE))
+		goto stop;
 
 	if (has_not_enough_free_secs(sbi))
-		old_free_secs = reserved_sections(sbi);
-	else
-		old_free_secs = free_sections(sbi);
-
-	while (sbi->sb->s_flags & MS_ACTIVE) {
-		int i;
-		if (has_not_enough_free_secs(sbi))
-			gc_type = FG_GC;
+		gc_type = FG_GC;
 
-		cur_free_secs = free_sections(sbi) + nfree;
+	if (!__get_victim(sbi, &segno, gc_type, NO_CHECK_TYPE))
+		goto stop;
 
-		/* We got free space successfully. */
-		if (nGC < cur_free_secs - old_free_secs)
-			break;
-
-		if (!__get_victim(sbi, &segno, gc_type, NO_CHECK_TYPE))
+	for (i = 0; i < sbi->segs_per_sec; i++) {
+		/*
+		 * do_garbage_collect will give us three gc_status:
+		 * GC_ERROR, GC_DONE, and GC_BLOCKED.
+		 * If GC is finished uncleanly, we have to return
+		 * the victim to dirty segment list.
+		 */
+		gc_status = do_garbage_collect(sbi, segno + i, &ilist, gc_type);
+		if (gc_status != GC_DONE)
 			break;
-
-		for (i = 0; i < sbi->segs_per_sec; i++) {
-			/*
-			 * do_garbage_collect will give us three gc_status:
-			 * GC_ERROR, GC_DONE, and GC_BLOCKED.
-			 * If GC is finished uncleanly, we have to return
-			 * the victim to dirty segment list.
-			 */
-			gc_status = do_garbage_collect(sbi, segno + i,
-					&ilist, gc_type);
-			if (gc_status != GC_DONE)
-				goto stop;
-			nfree++;
-		}
 	}
-stop:
-	if (has_not_enough_free_secs(sbi) || gc_status == GC_BLOCKED) {
+	if (has_not_enough_free_secs(sbi)) {
 		write_checkpoint(sbi, (gc_status == GC_BLOCKED), false);
-		if (nfree)
+		if (has_not_enough_free_secs(sbi))
 			goto gc_more;
 	}
+stop:
 	mutex_unlock(&sbi->gc_mutex);
 
 	put_gc_inode(&ilist);
-	BUG_ON(!list_empty(&ilist));
 	return gc_status;
 }
 
@@ -715,7 +701,7 @@ void build_gc_manager(struct f2fs_sb_info *sbi)
 	DIRTY_I(sbi)->v_ops = &default_v_ops;
 }
 
-int create_gc_caches(void)
+int __init create_gc_caches(void)
 {
 	winode_slab = f2fs_kmem_cache_create("f2fs_gc_inodes",
 			sizeof(struct inode_entry), NULL);
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index bf20b4d0321..79424177732 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -217,6 +217,9 @@ int f2fs_write_inode(struct inode *inode, struct writeback_control *wbc)
 			inode->i_ino == F2FS_META_INO(sbi))
 		return 0;
 
+	if (wbc)
+		f2fs_balance_fs(sbi);
+
 	node_page = get_node_page(sbi, inode->i_ino);
 	if (IS_ERR(node_page))
 		return PTR_ERR(node_page);
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 5066bfd256c..9bda63c9c16 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1124,6 +1124,12 @@ static int f2fs_write_node_page(struct page *page,
 	return 0;
 }
 
+/*
+ * It is very important to gather dirty pages and write at once, so that we can
+ * submit a big bio without interfering other data writes.
+ * Be default, 512 pages (2MB), a segment size, is quite reasonable.
+ */
+#define COLLECT_DIRTY_NODES	512
 static int f2fs_write_node_pages(struct address_space *mapping,
 			    struct writeback_control *wbc)
 {
@@ -1131,17 +1137,16 @@ static int f2fs_write_node_pages(struct address_space *mapping,
 	struct block_device *bdev = sbi->sb->s_bdev;
 	long nr_to_write = wbc->nr_to_write;
 
-	if (wbc->for_kupdate)
-		return 0;
-
-	if (get_pages(sbi, F2FS_DIRTY_NODES) == 0)
-		return 0;
-
+	/* First check balancing cached NAT entries */
 	if (try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK)) {
 		write_checkpoint(sbi, false, false);
 		return 0;
 	}
 
+	/* collect a number of dirty node pages and write together */
+	if (get_pages(sbi, F2FS_DIRTY_NODES) < COLLECT_DIRTY_NODES)
+		return 0;
+
 	/* if mounting is failed, skip writing node pages */
 	wbc->nr_to_write = bio_get_nr_vecs(bdev);
 	sync_node_pages(sbi, 0, wbc);
@@ -1732,7 +1737,7 @@ void destroy_node_manager(struct f2fs_sb_info *sbi)
 	kfree(nm_i);
 }
 
-int create_node_manager_caches(void)
+int __init create_node_manager_caches(void)
 {
 	nat_entry_slab = f2fs_kmem_cache_create("nat_entry",
 			sizeof(struct nat_entry), NULL);
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index b571fee677d..f42e4060b39 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -67,7 +67,7 @@ static int recover_dentry(struct page *ipage, struct inode *inode)
 		kunmap(page);
 		f2fs_put_page(page, 0);
 	} else {
-		f2fs_add_link(&dent, inode);
+		err = f2fs_add_link(&dent, inode);
 	}
 	iput(dir);
 out:
@@ -151,7 +151,6 @@ static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
 				goto out;
 			}
 
-			INIT_LIST_HEAD(&entry->list);
 			list_add_tail(&entry->list, head);
 			entry->blkaddr = blkaddr;
 		}
@@ -174,10 +173,9 @@ out:
 static void destroy_fsync_dnodes(struct f2fs_sb_info *sbi,
 					struct list_head *head)
 {
-	struct list_head *this;
-	struct fsync_inode_entry *entry;
-	list_for_each(this, head) {
-		entry = list_entry(this, struct fsync_inode_entry, list);
+	struct fsync_inode_entry *entry, *tmp;
+
+	list_for_each_entry_safe(entry, tmp, head, list) {
 		iput(entry->inode);
 		list_del(&entry->list);
 		kmem_cache_free(fsync_entry_slab, entry);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index de6240922b0..4b009906658 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -31,7 +31,7 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi)
 	 */
 	if (has_not_enough_free_secs(sbi)) {
 		mutex_lock(&sbi->gc_mutex);
-		f2fs_gc(sbi, 1);
+		f2fs_gc(sbi);
 	}
 }
 
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 08a94c814bd..37fad04c866 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -53,6 +53,18 @@ static match_table_t f2fs_tokens = {
 	{Opt_err, NULL},
 };
 
+void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	printk("%sF2FS-fs (%s): %pV\n", level, sb->s_id, &vaf);
+	va_end(args);
+}
+
 static void init_once(void *foo)
 {
 	struct f2fs_inode_info *fi = (struct f2fs_inode_info *) foo;
@@ -125,6 +137,8 @@ int f2fs_sync_fs(struct super_block *sb, int sync)
 
 	if (sync)
 		write_checkpoint(sbi, false, false);
+	else
+		f2fs_balance_fs(sbi);
 
 	return 0;
 }
@@ -247,7 +261,8 @@ static const struct export_operations f2fs_export_ops = {
 	.get_parent = f2fs_get_parent,
 };
 
-static int parse_options(struct f2fs_sb_info *sbi, char *options)
+static int parse_options(struct super_block *sb, struct f2fs_sb_info *sbi,
+				char *options)
 {
 	substring_t args[MAX_OPT_ARGS];
 	char *p;
@@ -286,7 +301,8 @@ static int parse_options(struct f2fs_sb_info *sbi, char *options)
 			break;
 #else
 		case Opt_nouser_xattr:
-			pr_info("nouser_xattr options not supported\n");
+			f2fs_msg(sb, KERN_INFO,
+				"nouser_xattr options not supported");
 			break;
 #endif
 #ifdef CONFIG_F2FS_FS_POSIX_ACL
@@ -295,7 +311,7 @@ static int parse_options(struct f2fs_sb_info *sbi, char *options)
 			break;
 #else
 		case Opt_noacl:
-			pr_info("noacl options not supported\n");
+			f2fs_msg(sb, KERN_INFO, "noacl options not supported");
 			break;
 #endif
 		case Opt_active_logs:
@@ -309,8 +325,9 @@ static int parse_options(struct f2fs_sb_info *sbi, char *options)
 			set_opt(sbi, DISABLE_EXT_IDENTIFY);
 			break;
 		default:
-			pr_err("Unrecognized mount option \"%s\" or missing value\n",
-					p);
+			f2fs_msg(sb, KERN_ERR,
+				"Unrecognized mount option \"%s\" or missing value",
+				p);
 			return -EINVAL;
 		}
 	}
@@ -337,23 +354,36 @@ static loff_t max_file_size(unsigned bits)
 	return result;
 }
 
-static int sanity_check_raw_super(struct f2fs_super_block *raw_super)
+static int sanity_check_raw_super(struct super_block *sb,
+			struct f2fs_super_block *raw_super)
 {
 	unsigned int blocksize;
 
-	if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic))
+	if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic)) {
+		f2fs_msg(sb, KERN_INFO,
+			"Magic Mismatch, valid(0x%x) - read(0x%x)",
+			F2FS_SUPER_MAGIC, le32_to_cpu(raw_super->magic));
 		return 1;
+	}
 
 	/* Currently, support only 4KB block size */
 	blocksize = 1 << le32_to_cpu(raw_super->log_blocksize);
-	if (blocksize != PAGE_CACHE_SIZE)
+	if (blocksize != PAGE_CACHE_SIZE) {
+		f2fs_msg(sb, KERN_INFO,
+			"Invalid blocksize (%u), supports only 4KB\n",
+			blocksize);
 		return 1;
+	}
 	if (le32_to_cpu(raw_super->log_sectorsize) !=
-					F2FS_LOG_SECTOR_SIZE)
+					F2FS_LOG_SECTOR_SIZE) {
+		f2fs_msg(sb, KERN_INFO, "Invalid log sectorsize");
 		return 1;
+	}
 	if (le32_to_cpu(raw_super->log_sectors_per_block) !=
-					F2FS_LOG_SECTORS_PER_BLOCK)
+					F2FS_LOG_SECTORS_PER_BLOCK) {
+		f2fs_msg(sb, KERN_INFO, "Invalid log sectors per block");
 		return 1;
+	}
 	return 0;
 }
 
@@ -413,14 +443,17 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	if (!sbi)
 		return -ENOMEM;
 
-	/* set a temporary block size */
-	if (!sb_set_blocksize(sb, F2FS_BLKSIZE))
+	/* set a block size */
+	if (!sb_set_blocksize(sb, F2FS_BLKSIZE)) {
+		f2fs_msg(sb, KERN_ERR, "unable to set blocksize");
 		goto free_sbi;
+	}
 
 	/* read f2fs raw super block */
 	raw_super_buf = sb_bread(sb, 0);
 	if (!raw_super_buf) {
 		err = -EIO;
+		f2fs_msg(sb, KERN_ERR, "unable to read superblock");
 		goto free_sbi;
 	}
 	raw_super = (struct f2fs_super_block *)
@@ -438,12 +471,14 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	set_opt(sbi, POSIX_ACL);
 #endif
 	/* parse mount options */
-	if (parse_options(sbi, (char *)data))
+	if (parse_options(sb, sbi, (char *)data))
 		goto free_sb_buf;
 
 	/* sanity checking of raw super */
-	if (sanity_check_raw_super(raw_super))
+	if (sanity_check_raw_super(sb, raw_super)) {
+		f2fs_msg(sb, KERN_ERR, "Can't find a valid F2FS filesystem");
 		goto free_sb_buf;
+	}
 
 	sb->s_maxbytes = max_file_size(le32_to_cpu(raw_super->log_blocksize));
 	sb->s_max_links = F2FS_LINK_MAX;
@@ -477,18 +512,23 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	/* get an inode for meta space */
 	sbi->meta_inode = f2fs_iget(sb, F2FS_META_INO(sbi));
 	if (IS_ERR(sbi->meta_inode)) {
+		f2fs_msg(sb, KERN_ERR, "Failed to read F2FS meta data inode");
 		err = PTR_ERR(sbi->meta_inode);
 		goto free_sb_buf;
 	}
 
 	err = get_valid_checkpoint(sbi);
-	if (err)
+	if (err) {
+		f2fs_msg(sb, KERN_ERR, "Failed to get valid F2FS checkpoint");
 		goto free_meta_inode;
+	}
 
 	/* sanity checking of checkpoint */
 	err = -EINVAL;
-	if (sanity_check_ckpt(raw_super, sbi->ckpt))
+	if (sanity_check_ckpt(raw_super, sbi->ckpt)) {
+		f2fs_msg(sb, KERN_ERR, "Invalid F2FS checkpoint");
 		goto free_cp;
+	}
 
 	sbi->total_valid_node_count =
 				le32_to_cpu(sbi->ckpt->valid_node_count);
@@ -502,25 +542,28 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	INIT_LIST_HEAD(&sbi->dir_inode_list);
 	spin_lock_init(&sbi->dir_inode_lock);
 
-	/* init super block */
-	if (!sb_set_blocksize(sb, sbi->blocksize))
-		goto free_cp;
-
 	init_orphan_info(sbi);
 
 	/* setup f2fs internal modules */
 	err = build_segment_manager(sbi);
-	if (err)
+	if (err) {
+		f2fs_msg(sb, KERN_ERR,
+			"Failed to initialize F2FS segment manager");
 		goto free_sm;
+	}
 	err = build_node_manager(sbi);
-	if (err)
+	if (err) {
+		f2fs_msg(sb, KERN_ERR,
+			"Failed to initialize F2FS node manager");
 		goto free_nm;
+	}
 
 	build_gc_manager(sbi);
 
 	/* get an inode for node space */
 	sbi->node_inode = f2fs_iget(sb, F2FS_NODE_INO(sbi));
 	if (IS_ERR(sbi->node_inode)) {
+		f2fs_msg(sb, KERN_ERR, "Failed to read node inode");
 		err = PTR_ERR(sbi->node_inode);
 		goto free_nm;
 	}
@@ -533,6 +576,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	/* read root inode and dentry */
 	root = f2fs_iget(sb, F2FS_ROOT_INO(sbi));
 	if (IS_ERR(root)) {
+		f2fs_msg(sb, KERN_ERR, "Failed to read root inode");
 		err = PTR_ERR(root);
 		goto free_node_inode;
 	}
@@ -596,7 +640,7 @@ static struct file_system_type f2fs_fs_type = {
 	.fs_flags	= FS_REQUIRES_DEV,
 };
 
-static int init_inodecache(void)
+static int __init init_inodecache(void)
 {
 	f2fs_inode_cachep = f2fs_kmem_cache_create("f2fs_inode_cache",
 			sizeof(struct f2fs_inode_info), NULL);
@@ -631,14 +675,17 @@ static int __init init_f2fs_fs(void)
 	err = create_checkpoint_caches();
 	if (err)
 		goto fail;
-	return register_filesystem(&f2fs_fs_type);
+	err = register_filesystem(&f2fs_fs_type);
+	if (err)
+		goto fail;
+	f2fs_create_root_stats();
 fail:
 	return err;
 }
 
 static void __exit exit_f2fs_fs(void)
 {
-	destroy_root_stats();
+	f2fs_destroy_root_stats();
 	unregister_filesystem(&f2fs_fs_type);
 	destroy_checkpoint_caches();
 	destroy_gc_caches();
diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index 940136a3d3a..8038c049650 100644
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -318,6 +318,8 @@ int f2fs_setxattr(struct inode *inode, int name_index, const char *name,
 	if (name_len > 255 || value_len > MAX_VALUE_LEN)
 		return -ERANGE;
 
+	f2fs_balance_fs(sbi);
+
 	mutex_lock_op(sbi, NODE_NEW);
 	if (!fi->i_xattr_nid) {
 		/* Allocate new attribute block */