X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=fs%2Ffs-writeback.c;h=892643dc9af10a1a6fbf7c858fd430ab209a5724;hb=53561d10e5820b681714aebb9b6a56f7efd4269b;hp=c150fb8613857a999c7f05ce1841067f648cc42a;hpb=70790a4b5cd6c0291e5b1a2836e2832d46036ac6;p=linux-2.6.git

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index c150fb861..892643dc9 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -133,10 +133,11 @@ out:
 
 EXPORT_SYMBOL(__mark_inode_dirty);
 
-static void write_inode(struct inode *inode, int sync)
+static int write_inode(struct inode *inode, int sync)
 {
 	if (inode->i_sb->s_op->write_inode && !is_bad_inode(inode))
-		inode->i_sb->s_op->write_inode(inode, sync);
+		return inode->i_sb->s_op->write_inode(inode, sync);
+	return 0;
 }
 
 /*
@@ -170,8 +171,11 @@ __sync_single_inode(struct inode *inode, struct writeback_control *wbc)
 	ret = do_writepages(mapping, wbc);
 
 	/* Don't write the inode if only I_DIRTY_PAGES was set */
-	if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC))
-		write_inode(inode, wait);
+	if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) {
+		int err = write_inode(inode, wait);
+		if (ret == 0)
+			ret = err;
+	}
 
 	if (wait) {
 		int err = filemap_fdatawait(mapping);
@@ -213,8 +217,9 @@ __sync_single_inode(struct inode *inode, struct writeback_control *wbc)
 		} else if (inode->i_state & I_DIRTY) {
 			/*
 			 * Someone redirtied the inode while were writing back
-			 * the pages: nothing to do.
+			 * the pages.
 			 */
+			list_move(&inode->i_list, &sb->s_dirty);
 		} else if (atomic_read(&inode->i_count)) {
 			/*
 			 * The inode is clean, inuse
@@ -225,7 +230,6 @@ __sync_single_inode(struct inode *inode, struct writeback_control *wbc)
 			 * The inode is clean, unused
 			 */
 			list_move(&inode->i_list, &inode_unused);
-			inodes_stat.nr_unused++;
 		}
 	}
 	wake_up_inode(inode);
@@ -233,12 +237,20 @@ __sync_single_inode(struct inode *inode, struct writeback_control *wbc)
 }
 
 /*
- * Write out an inode's dirty pages.  Called under inode_lock.
+ * Write out an inode's dirty pages.  Called under inode_lock.  Either the
+ * caller has ref on the inode (either via __iget or via syscall against an fd)
+ * or the inode has I_WILL_FREE set (via generic_forget_inode)
  */
 static int
-__writeback_single_inode(struct inode *inode,
-			struct writeback_control *wbc)
+__writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
 {
+	wait_queue_head_t *wqh;
+
+	if (!atomic_read(&inode->i_count))
+		WARN_ON(!(inode->i_state & (I_WILL_FREE|I_FREEING)));
+	else
+		WARN_ON(inode->i_state & I_WILL_FREE);
+
 	if ((wbc->sync_mode != WB_SYNC_ALL) && (inode->i_state & I_LOCK)) {
 		list_move(&inode->i_list, &inode->i_sb->s_dirty);
 		return 0;
@@ -247,12 +259,16 @@ __writeback_single_inode(struct inode *inode,
 	/*
 	 * It's a data-integrity sync.  We must wait.
 	 */
-	while (inode->i_state & I_LOCK) {
-		__iget(inode);
-		spin_unlock(&inode_lock);
-		__wait_on_inode(inode);
-		iput(inode);
-		spin_lock(&inode_lock);
+	if (inode->i_state & I_LOCK) {
+		DEFINE_WAIT_BIT(wq, &inode->i_state, __I_LOCK);
+
+		wqh = bit_waitqueue(&inode->i_state, __I_LOCK);
+		do {
+			spin_unlock(&inode_lock);
+			__wait_on_bit(wqh, &wq, inode_wait,
+							TASK_UNINTERRUPTIBLE);
+			spin_lock(&inode_lock);
+		} while (inode->i_state & I_LOCK);
 	}
 	return __sync_single_inode(inode, wbc);
 }
@@ -302,15 +318,21 @@ sync_sb_inodes(struct super_block *sb, struct writeback_control *wbc)
 		struct backing_dev_info *bdi = mapping->backing_dev_info;
 		long pages_skipped;
 
-		if (bdi->memory_backed) {
+		if (!bdi_cap_writeback_dirty(bdi)) {
+			list_move(&inode->i_list, &sb->s_dirty);
 			if (sb == blockdev_superblock) {
 				/*
 				 * Dirty memory-backed blockdev: the ramdisk
-				 * driver does this.
+				 * driver does this.  Skip just this inode
 				 */
-				list_move(&inode->i_list, &sb->s_dirty);
 				continue;
 			}
+			/*
+			 * Dirty memory-backed inode against a filesystem other
+			 * than the kernel-internal bdev filesystem.  Skip the
+			 * entire superblock.
+			 */
+			break;
 		}
 
 		if (wbc->nonblocking && bdi_write_congested(bdi)) {
@@ -359,8 +381,8 @@ sync_sb_inodes(struct super_block *sb, struct writeback_control *wbc)
 			list_move(&inode->i_list, &sb->s_dirty);
 		}
 		spin_unlock(&inode_lock);
-		cond_resched();
 		iput(inode);
+		cond_resched();
 		spin_lock(&inode_lock);
 		if (wbc->nr_to_write <= 0)
 			break;
@@ -393,7 +415,6 @@ writeback_inodes(struct writeback_control *wbc)
 	struct super_block *sb;
 
 	might_sleep();
-	spin_lock(&inode_lock);
 	spin_lock(&sb_lock);
 restart:
 	sb = sb_entry(super_blocks.prev);
@@ -408,19 +429,21 @@ restart:
 			 * be unmounted by the time it is released.
 			 */
 			if (down_read_trylock(&sb->s_umount)) {
-				if (sb->s_root)
+				if (sb->s_root) {
+					spin_lock(&inode_lock);
 					sync_sb_inodes(sb, wbc);
+					spin_unlock(&inode_lock);
+				}
 				up_read(&sb->s_umount);
 			}
 			spin_lock(&sb_lock);
-			if (__put_super(sb))
+			if (__put_super_and_need_restart(sb))
 				goto restart;
 		}
 		if (wbc->nr_to_write <= 0)
 			break;
 	}
 	spin_unlock(&sb_lock);
-	spin_unlock(&inode_lock);
 }
 
 /*
@@ -438,9 +461,11 @@ void sync_inodes_sb(struct super_block *sb, int wait)
 {
 	struct writeback_control wbc = {
 		.sync_mode	= wait ? WB_SYNC_ALL : WB_SYNC_HOLD,
+		.range_start	= 0,
+		.range_end	= LLONG_MAX,
 	};
-	unsigned long nr_dirty = read_page_state(nr_dirty);
-	unsigned long nr_unstable = read_page_state(nr_unstable);
+	unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY);
+	unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS);
 
 	wbc.nr_to_write = nr_dirty + nr_unstable +
 			(inodes_stat.nr_inodes - inodes_stat.nr_unused) +
@@ -465,34 +490,9 @@ static void set_sb_syncing(int val)
 	spin_unlock(&sb_lock);
 }
 
-/*
- * Find a superblock with inodes that need to be synced
- */
-static struct super_block *get_super_to_sync(void)
-{
-	struct super_block *sb;
-restart:
-	spin_lock(&sb_lock);
-	sb = sb_entry(super_blocks.prev);
-	for (; sb != sb_entry(&super_blocks); sb = sb_entry(sb->s_list.prev)) {
-		if (sb->s_syncing)
-			continue;
-		sb->s_syncing = 1;
-		sb->s_count++;
-		spin_unlock(&sb_lock);
-		down_read(&sb->s_umount);
-		if (!sb->s_root) {
-			drop_super(sb);
-			goto restart;
-		}
-		return sb;
-	}
-	spin_unlock(&sb_lock);
-	return NULL;
-}
-
 /**
- * sync_inodes
+ * sync_inodes - writes all inodes to disk
+ * @wait: wait for completion
  *
  * sync_inodes() goes through each super block's dirty inode list, writes the
  * inodes out, waits on the writeout and puts the inodes back on the normal
@@ -509,51 +509,72 @@ restart:
  * outstanding dirty inodes, the writeback goes block-at-a-time within the
  * filesystem's write_inode().  This is extremely slow.
  */
-void sync_inodes(int wait)
+static void __sync_inodes(int wait)
 {
 	struct super_block *sb;
 
-	set_sb_syncing(0);
-	while ((sb = get_super_to_sync()) != NULL) {
-		sync_inodes_sb(sb, 0);
-		sync_blockdev(sb->s_bdev);
-		drop_super(sb);
+	spin_lock(&sb_lock);
+restart:
+	list_for_each_entry(sb, &super_blocks, s_list) {
+		if (sb->s_syncing)
+			continue;
+		sb->s_syncing = 1;
+		sb->s_count++;
+		spin_unlock(&sb_lock);
+		down_read(&sb->s_umount);
+		if (sb->s_root) {
+			sync_inodes_sb(sb, wait);
+			sync_blockdev(sb->s_bdev);
+		}
+		up_read(&sb->s_umount);
+		spin_lock(&sb_lock);
+		if (__put_super_and_need_restart(sb))
+			goto restart;
 	}
+	spin_unlock(&sb_lock);
+}
+
+void sync_inodes(int wait)
+{
+	set_sb_syncing(0);
+	__sync_inodes(0);
+
 	if (wait) {
 		set_sb_syncing(0);
-		while ((sb = get_super_to_sync()) != NULL) {
-			sync_inodes_sb(sb, 1);
-			sync_blockdev(sb->s_bdev);
-			drop_super(sb);
-		}
+		__sync_inodes(1);
 	}
 }
 
 /**
- *	write_inode_now	-	write an inode to disk
- *	@inode: inode to write to disk
- *	@sync: whether the write should be synchronous or not
+ * write_inode_now	-	write an inode to disk
+ * @inode: inode to write to disk
+ * @sync: whether the write should be synchronous or not
  *
- *	This function commits an inode to disk immediately if it is
- *	dirty. This is primarily needed by knfsd.
+ * This function commits an inode to disk immediately if it is dirty. This is
+ * primarily needed by knfsd.
+ *
+ * The caller must either have a ref on the inode or must have set I_WILL_FREE.
  */
- 
-void write_inode_now(struct inode *inode, int sync)
+int write_inode_now(struct inode *inode, int sync)
 {
+	int ret;
 	struct writeback_control wbc = {
 		.nr_to_write = LONG_MAX,
 		.sync_mode = WB_SYNC_ALL,
+		.range_start = 0,
+		.range_end = LLONG_MAX,
 	};
 
-	if (inode->i_mapping->backing_dev_info->memory_backed)
-		return;
+	if (!mapping_cap_writeback_dirty(inode->i_mapping))
+		wbc.nr_to_write = 0;
 
 	might_sleep();
 	spin_lock(&inode_lock);
-	__writeback_single_inode(inode, &wbc);
+	ret = __writeback_single_inode(inode, &wbc);
 	spin_unlock(&inode_lock);
 	if (sync)
 		wait_on_inode(inode);
+	return ret;
 }
 EXPORT_SYMBOL(write_inode_now);
 
@@ -582,13 +603,14 @@ EXPORT_SYMBOL(sync_inode);
 /**
  * generic_osync_inode - flush all dirty data for a given inode to disk
  * @inode: inode to write
+ * @mapping: the address_space that should be flushed
  * @what:  what to write and wait upon
  *
  * This can be called by file_write functions for files which have the
  * O_SYNC flag set, to flush dirty writes to disk.
  *
  * @what is a bitmask, specifying which part of the inode's data should be
- * written and waited upon:
+ * written and waited upon.
  *
  *    OSYNC_DATA:     i_mapping's dirty data
  *    OSYNC_METADATA: the buffers at i_mapping->private_list
@@ -601,7 +623,6 @@ int generic_osync_inode(struct inode *inode, struct address_space *mapping, int
 	int need_write_inode_now = 0;
 	int err2;
 
-	current->flags |= PF_SYNCWRITE;
 	if (what & OSYNC_DATA)
 		err = filemap_fdatawrite(mapping);
 	if (what & (OSYNC_METADATA|OSYNC_DATA)) {
@@ -614,7 +635,6 @@ int generic_osync_inode(struct inode *inode, struct address_space *mapping, int
 		if (!err)
 			err = err2;
 	}
-	current->flags &= ~PF_SYNCWRITE;
 
 	spin_lock(&inode_lock);
 	if ((inode->i_state & I_DIRTY) &&
@@ -622,8 +642,11 @@ int generic_osync_inode(struct inode *inode, struct address_space *mapping, int
 		need_write_inode_now = 1;
 	spin_unlock(&inode_lock);
 
-	if (need_write_inode_now)
-		write_inode_now(inode, 1);
+	if (need_write_inode_now) {
+		err2 = write_inode_now(inode, 1);
+		if (!err)
+			err = err2;
+	}
 	else
 		wait_on_inode(inode);
 
@@ -651,8 +674,9 @@ int writeback_acquire(struct backing_dev_info *bdi)
 
 /**
  * writeback_in_progress: determine whether there is writeback in progress
- *                        against a backing device.
  * @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)
 {