X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=fs%2Ffs-writeback.c;h=d0ff0b8cf30988a23ad144f92f8b7543790bbe67;hb=9183482f5d4a2de00f66641b974e7f351d41b675;hp=06557679ca411d6fbce09a33dddd042f938ecbc2;hpb=49ccf74aaf6b53751dc0ae06ded9bb39343da822;p=linux-2.6-omap-h63xx.git

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 06557679ca4..d0ff0b8cf30 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -8,7 +8,7 @@
  * pages against inodes.  ie: data writeback.  Writeout of the
  * inode itself is not handled here.
  *
- * 10Apr2002	akpm@zip.com.au
+ * 10Apr2002	Andrew Morton
  *		Split out of fs/inode.c
  *		Additions for address_space-based writeback
  */
@@ -25,6 +25,45 @@
 #include <linux/buffer_head.h>
 #include "internal.h"
 
+
+/**
+ * writeback_acquire - attempt to get exclusive writeback access to a device
+ * @bdi: the device's backing_dev_info structure
+ *
+ * It is a waste of resources to have more than one pdflush thread blocked on
+ * a single request queue.  Exclusion at the request_queue level is obtained
+ * via a flag in the request_queue's backing_dev_info.state.
+ *
+ * Non-request_queue-backed address_spaces will share default_backing_dev_info,
+ * unless they implement their own.  Which is somewhat inefficient, as this
+ * may prevent concurrent writeback against multiple devices.
+ */
+static int writeback_acquire(struct backing_dev_info *bdi)
+{
+	return !test_and_set_bit(BDI_pdflush, &bdi->state);
+}
+
+/**
+ * writeback_in_progress - determine whether there is writeback in progress
+ * @bdi: the device's backing_dev_info structure.
+ *
+ * Determine whether there is writeback in progress against a backing device.
+ */
+int writeback_in_progress(struct backing_dev_info *bdi)
+{
+	return test_bit(BDI_pdflush, &bdi->state);
+}
+
+/**
+ * writeback_release - relinquish exclusive writeback access against a device.
+ * @bdi: the device's backing_dev_info structure
+ */
+static void writeback_release(struct backing_dev_info *bdi)
+{
+	BUG_ON(!writeback_in_progress(bdi));
+	clear_bit(BDI_pdflush, &bdi->state);
+}
+
 /**
  *	__mark_inode_dirty -	internal function
  *	@inode: inode to mark
@@ -385,8 +424,6 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
  * WB_SYNC_HOLD is a hack for sys_sync(): reattach the inode to sb->s_dirty so
  * that it can be located for waiting on in __writeback_single_inode().
  *
- * Called under inode_lock.
- *
  * If `bdi' is non-zero then we're being asked to writeback a specific queue.
  * This function assumes that the blockdev superblock's inodes are backed by
  * a variety of queues, so all inodes are searched.  For other superblocks,
@@ -402,11 +439,12 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
  * on the writer throttling path, and we get decent balancing between many
  * throttled threads: we don't want them all piling up on inode_sync_wait.
  */
-static void
-sync_sb_inodes(struct super_block *sb, struct writeback_control *wbc)
+void generic_sync_sb_inodes(struct super_block *sb,
+				struct writeback_control *wbc)
 {
 	const unsigned long start = jiffies;	/* livelock avoidance */
 
+	spin_lock(&inode_lock);
 	if (!wbc->for_kupdate || list_empty(&sb->s_io))
 		queue_io(sb, wbc->older_than_this);
 
@@ -485,8 +523,16 @@ sync_sb_inodes(struct super_block *sb, struct writeback_control *wbc)
 		if (!list_empty(&sb->s_more_io))
 			wbc->more_io = 1;
 	}
+	spin_unlock(&inode_lock);
 	return;		/* Leave any unwritten inodes on s_io */
 }
+EXPORT_SYMBOL_GPL(generic_sync_sb_inodes);
+
+static void sync_sb_inodes(struct super_block *sb,
+				struct writeback_control *wbc)
+{
+	generic_sync_sb_inodes(sb, wbc);
+}
 
 /*
  * Start writeback of dirty pagecache data against all unlocked inodes.
@@ -526,11 +572,8 @@ restart:
 			 * be unmounted by the time it is released.
 			 */
 			if (down_read_trylock(&sb->s_umount)) {
-				if (sb->s_root) {
-					spin_lock(&inode_lock);
+				if (sb->s_root)
 					sync_sb_inodes(sb, wbc);
-					spin_unlock(&inode_lock);
-				}
 				up_read(&sb->s_umount);
 			}
 			spin_lock(&sb_lock);
@@ -568,9 +611,7 @@ void sync_inodes_sb(struct super_block *sb, int wait)
 			(inodes_stat.nr_inodes - inodes_stat.nr_unused) +
 			nr_dirty + nr_unstable;
 	wbc.nr_to_write += wbc.nr_to_write / 2;		/* Bit more for luck */
-	spin_lock(&inode_lock);
 	sync_sb_inodes(sb, &wbc);
-	spin_unlock(&inode_lock);
 }
 
 /*
@@ -747,43 +788,4 @@ int generic_osync_inode(struct inode *inode, struct address_space *mapping, int
 
 	return err;
 }
-
 EXPORT_SYMBOL(generic_osync_inode);
-
-/**
- * writeback_acquire - attempt to get exclusive writeback access to a device
- * @bdi: the device's backing_dev_info structure
- *
- * It is a waste of resources to have more than one pdflush thread blocked on
- * a single request queue.  Exclusion at the request_queue level is obtained
- * via a flag in the request_queue's backing_dev_info.state.
- *
- * Non-request_queue-backed address_spaces will share default_backing_dev_info,
- * unless they implement their own.  Which is somewhat inefficient, as this
- * may prevent concurrent writeback against multiple devices.
- */
-int writeback_acquire(struct backing_dev_info *bdi)
-{
-	return !test_and_set_bit(BDI_pdflush, &bdi->state);
-}
-
-/**
- * writeback_in_progress - determine whether there is writeback in progress
- * @bdi: the device's backing_dev_info structure.
- *
- * Determine whether there is writeback in progress against a backing device.
- */
-int writeback_in_progress(struct backing_dev_info *bdi)
-{
-	return test_bit(BDI_pdflush, &bdi->state);
-}
-
-/**
- * writeback_release - relinquish exclusive writeback access against a device.
- * @bdi: the device's backing_dev_info structure
- */
-void writeback_release(struct backing_dev_info *bdi)
-{
-	BUG_ON(!writeback_in_progress(bdi));
-	clear_bit(BDI_pdflush, &bdi->state);
-}