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Commit b6520c81 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Al Viro
Browse files

cleanup d_add_ci 



Make sure that comments describe what's going on and not how, and always
use __d_instantiate instead of two separate branches, one with
d_instantiate and one with __d_instantiate.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 2b1c6bd7

fs/dcache.c

+18 −30
Original line number Diff line number Diff line
@@ -1247,15 +1247,18 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode, 
	struct dentry *found;

	struct dentry *new;



	/* Does a dentry matching the name exist already? */

	/*

	 * First check if a dentry matching the name already exists,

	 * if not go ahead and create it now.

	 */

	found = d_hash_and_lookup(dentry->d_parent, name);

	/* If not, create it now and return */

	if (!found) {

		new = d_alloc(dentry->d_parent, name);

		if (!new) {

			error = -ENOMEM;

			goto err_out;

		}



		found = d_splice_alias(inode, new);

		if (found) {

			dput(new);
@@ -1263,61 +1266,46 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode, 
		}

		return new;

	}

	/* Matching dentry exists, check if it is negative. */



	/*

	 * If a matching dentry exists, and it's not negative use it.

	 *

	 * Decrement the reference count to balance the iget() done

	 * earlier on.

	 */

	if (found->d_inode) {

		if (unlikely(found->d_inode != inode)) {

			/* This can't happen because bad inodes are unhashed. */

			BUG_ON(!is_bad_inode(inode));

			BUG_ON(!is_bad_inode(found->d_inode));

		}

		/*

		 * Already have the inode and the dentry attached, decrement

		 * the reference count to balance the iget() done

		 * earlier on.  We found the dentry using d_lookup() so it

		 * cannot be disconnected and thus we do not need to worry

		 * about any NFS/disconnectedness issues here.

		 */

		iput(inode);

		return found;

	}



	/*

	 * Negative dentry: instantiate it unless the inode is a directory and

	 * has a 'disconnected' dentry (i.e. IS_ROOT and DCACHE_DISCONNECTED),

	 * in which case d_move() that in place of the found dentry.

	 * already has a dentry.

	 */

	if (!S_ISDIR(inode->i_mode)) {

		/* Not a directory; everything is easy. */

		d_instantiate(found, inode);

		return found;

	}

	spin_lock(&dcache_lock);

	if (list_empty(&inode->i_dentry)) {

		/*

		 * Directory without a 'disconnected' dentry; we need to do

		 * d_instantiate() by hand because it takes dcache_lock which

		 * we already hold.

		 */

	if (!S_ISDIR(inode->i_mode) || list_empty(&inode->i_dentry)) {

		__d_instantiate(found, inode);

		spin_unlock(&dcache_lock);

		security_d_instantiate(found, inode);

		return found;

	}



	/*

	 * Directory with a 'disconnected' dentry; get a reference to the

	 * 'disconnected' dentry.

	 * In case a directory already has a (disconnected) entry grab a

	 * reference to it, move it in place and use it.

	 */

	new = list_entry(inode->i_dentry.next, struct dentry, d_alias);

	dget_locked(new);

	spin_unlock(&dcache_lock);

	/* Do security vodoo. */

	security_d_instantiate(found, inode);

	/* Move new in place of found. */

	d_move(new, found);

	/* Balance the iget() we did above. */

	iput(inode);

	/* Throw away found. */

	dput(found);

	/* Use new as the actual dentry. */

	return new;



err_out: