[PATCH v2 4/7] VFS: Rename and refactor writeback_inodes_sb_if_idle

From: Kamal Mostafa <kamal@canonical.com>
To: Jan Kara <jack@suse.cz>, Alexander Viro <viro@zeniv.linux.org.uk>,
	Andreas Dilger <adilger.kernel@dilger.ca>,
	Matthew Wilcox <matthew@wil.cx>,
	Randy Dunlap <rdunlap@xenotime.net>, Theodore Tso <tytso@mit.edu>
Cc: linux-doc@vger.kernel.org, linux-ext4@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	Surbhi Palande <csurbhi@gmail.com>,
	Valerie Aurora <val@vaaconsulting.com>,
	Kamal Mostafa <kamal@canonical.com>,
	Christopher Chaltain <christopher.chaltain@canonical.com>,
	"Peter M. Petrakis" <peter.petrakis@canonical.com>,
	Mikulas Patocka <mpatocka@redhat.com>
Subject: [PATCH v2 4/7] VFS: Rename and refactor writeback_inodes_sb_if_idle
Date: Thu,  8 Dec 2011 10:04:34 -0800	[thread overview]
Message-ID: <1323367477-21685-5-git-send-email-kamal@canonical.com> (raw)
In-Reply-To: <1323367477-21685-1-git-send-email-kamal@canonical.com>

Rename writeback_inodes_sb{_nr}_if_idle to try_to_writeback_inodes_sb{_nr}
and refactor to avoid duplicating logic.

Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 fs/btrfs/extent-tree.c    |    2 +-
 fs/ext4/inode.c           |    2 +-
 fs/fs-writeback.c         |   25 +++++++++++--------------
 include/linux/writeback.h |    4 ++--
 4 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index f0d5718..6f6fe2b 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3416,7 +3416,7 @@ static int shrink_delalloc(struct btrfs_root *root, u64 to_reclaim,
 		smp_mb();
 		nr_pages = min_t(unsigned long, nr_pages,
 		       root->fs_info->delalloc_bytes >> PAGE_CACHE_SHIFT);
-		writeback_inodes_sb_nr_if_idle(root->fs_info->sb, nr_pages,
+		try_to_writeback_inodes_sb_nr(root->fs_info->sb, nr_pages,
 						WB_REASON_FS_FREE_SPACE);
 
 		spin_lock(&space_info->lock);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 848f436..0da75cd 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2373,7 +2373,7 @@ static int ext4_nonda_switch(struct super_block *sb)
 	 * start pushing delalloc when 1/2 of free blocks are dirty.
 	 */
 	if (free_blocks < 2 * dirty_blocks)
-		writeback_inodes_sb_if_idle(sb, WB_REASON_FS_FREE_SPACE);
+		try_to_writeback_inodes_sb(sb, WB_REASON_FS_FREE_SPACE);
 
 	return 0;
 }
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index eee01cd..ea89b3f 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -1271,45 +1271,42 @@ void writeback_inodes_sb(struct super_block *sb, enum wb_reason reason)
 EXPORT_SYMBOL(writeback_inodes_sb);
 
 /**
- * writeback_inodes_sb_if_idle	-	start writeback if none underway
+ * try_to_writeback_inodes_sb	-	start writeback if none underway
  * @sb: the superblock
  *
  * Invoke writeback_inodes_sb if no writeback is currently underway.
  * Returns 1 if writeback was started, 0 if not.
  */
-int writeback_inodes_sb_if_idle(struct super_block *sb, enum wb_reason reason)
+int try_to_writeback_inodes_sb(struct super_block *sb, enum wb_reason reason)
 {
-	if (!writeback_in_progress(sb->s_bdi)) {
-		down_read(&sb->s_umount);
-		writeback_inodes_sb(sb, reason);
-		up_read(&sb->s_umount);
-		return 1;
-	} else
-		return 0;
+	return try_to_writeback_inodes_sb_nr(sb, 0, reason);
 }
-EXPORT_SYMBOL(writeback_inodes_sb_if_idle);
+EXPORT_SYMBOL(try_to_writeback_inodes_sb);
 
 /**
- * writeback_inodes_sb_if_idle	-	start writeback if none underway
+ * try_to_writeback_inodes_sb_nr	-	start writeback if none underway
  * @sb: the superblock
  * @nr: the number of pages to write
  *
  * Invoke writeback_inodes_sb if no writeback is currently underway.
  * Returns 1 if writeback was started, 0 if not.
  */
-int writeback_inodes_sb_nr_if_idle(struct super_block *sb,
+int try_to_writeback_inodes_sb_nr(struct super_block *sb,
 				   unsigned long nr,
 				   enum wb_reason reason)
 {
 	if (!writeback_in_progress(sb->s_bdi)) {
 		down_read(&sb->s_umount);
-		writeback_inodes_sb_nr(sb, nr, reason);
+		if (nr == 0)
+			writeback_inodes_sb(sb, reason);
+		else
+			writeback_inodes_sb_nr(sb, nr, reason);
 		up_read(&sb->s_umount);
 		return 1;
 	} else
 		return 0;
 }
-EXPORT_SYMBOL(writeback_inodes_sb_nr_if_idle);
+EXPORT_SYMBOL(try_to_writeback_inodes_sb_nr);
 
 /**
  * sync_inodes_sb	-	sync sb inode pages
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index a378c29..e824225 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -89,8 +89,8 @@ int inode_wait(void *);
 void writeback_inodes_sb(struct super_block *, enum wb_reason reason);
 void writeback_inodes_sb_nr(struct super_block *, unsigned long nr,
 							enum wb_reason reason);
-int writeback_inodes_sb_if_idle(struct super_block *, enum wb_reason reason);
-int writeback_inodes_sb_nr_if_idle(struct super_block *, unsigned long nr,
+int try_to_writeback_inodes_sb(struct super_block *, enum wb_reason reason);
+int try_to_writeback_inodes_sb_nr(struct super_block *, unsigned long nr,
 							enum wb_reason reason);
 void sync_inodes_sb(struct super_block *);
 long writeback_inodes_wb(struct bdi_writeback *wb, long nr_pages,
-- 
1.7.5.4

