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Commit e2f99018 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Linus Torvalds
Browse files

[PATCH] exportfs: add find_acceptable_alias helper 



find_exported_dentry contains two duplicate loops to find an alias that the
acceptable callback likes.  Split this out to a new helper and switch from
list_for_each to list_for_each_entry to make it more readable.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarNeilBrown <neilb@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 846f2fcd

fs/exportfs/expfs.c

+36 −43
Original line number Diff line number Diff line
@@ -11,6 +11,33 @@ struct export_operations export_op_default; 


#define dprintk(fmt, args...) do{}while(0)



static struct dentry *

find_acceptable_alias(struct dentry *result,

		int (*acceptable)(void *context, struct dentry *dentry),

		void *context)

{

	struct dentry *dentry, *toput = NULL;



	spin_lock(&dcache_lock);

	list_for_each_entry(dentry, &result->d_inode->i_dentry, d_alias) {

		dget_locked(dentry);

		spin_unlock(&dcache_lock);

		if (toput)

			dput(toput);

		if (dentry != result && acceptable(context, dentry)) {

			dput(result);

			return dentry;

		}

		spin_lock(&dcache_lock);

		toput = dentry;

	}

	spin_unlock(&dcache_lock);



	if (toput)

		dput(toput);

	return NULL;

}



/**

 * find_exported_dentry - helper routine to implement export_operations->decode_fh

 * @sb:		The &super_block identifying the filesystem
@@ -52,8 +79,7 @@ find_exported_dentry(struct super_block *sb, void *obj, void *parent, 
	struct dentry *target_dir;

	int err;

	struct export_operations *nops = sb->s_export_op;

	struct list_head *le, *head;

	struct dentry *toput = NULL;

	struct dentry *alias;

	int noprogress;

	char nbuf[NAME_MAX+1];
@@ -79,27 +105,10 @@ find_exported_dentry(struct super_block *sb, void *obj, void *parent, 
			/* there is no other dentry, so fail */

			goto err_result;

		}

		/* try any other aliases */

		spin_lock(&dcache_lock);

		head = &result->d_inode->i_dentry;

		list_for_each(le, head) {

			struct dentry *dentry = list_entry(le, struct dentry, d_alias);

			dget_locked(dentry);

			spin_unlock(&dcache_lock);

			if (toput)

				dput(toput);

			toput = NULL;

			if (dentry != result &&

			    acceptable(context, dentry)) {

				dput(result);

				return dentry;

			}

			spin_lock(&dcache_lock);

			toput = dentry;

		}

		spin_unlock(&dcache_lock);

		if (toput)

			dput(toput);



		alias = find_acceptable_alias(result, acceptable, context);

		if (alias)

			return alias;

	}			



	/* It's a directory, or we are required to confirm the file's
@@ -258,26 +267,10 @@ find_exported_dentry(struct super_block *sb, void *obj, void *parent, 
	/* now result is properly connected, it is our best bet */

	if (acceptable(context, result))

		return result;

	/* one last try of the aliases.. */

	spin_lock(&dcache_lock);

	toput = NULL;

	head = &result->d_inode->i_dentry;

	list_for_each(le, head) {

		struct dentry *dentry = list_entry(le, struct dentry, d_alias);

		dget_locked(dentry);

		spin_unlock(&dcache_lock);

		if (toput) dput(toput);

		if (dentry != result &&

		    acceptable(context, dentry)) {

			dput(result);

			return dentry;

		}

		spin_lock(&dcache_lock);

		toput = dentry;

	}

	spin_unlock(&dcache_lock);

	if (toput)

		dput(toput);



	alias = find_acceptable_alias(result, acceptable, context);

	if (alias)

		return alias;



	/* drat - I just cannot find anything acceptable */

	dput(result);