Commit da502956 authored by Nick Piggin's avatar Nick Piggin
Browse files

fs: dcache scale d_unhashed 



Protect d_unhashed(dentry) condition with d_lock. This means keeping
DCACHE_UNHASHED bit in synch with hash manipulations.

Signed-off-by: default avatarNick Piggin <npiggin@kernel.dk>
parent b7ab39f6

arch/powerpc/platforms/cell/spufs/inode.c

+3 −0
Original line number Diff line number Diff line
@@ -166,6 +166,9 @@ static void spufs_prune_dir(struct dentry *dir) 
			__d_drop(dentry);

			spin_unlock(&dentry->d_lock);

			simple_unlink(dir->d_inode, dentry);

			/* XXX: what is dcache_lock protecting here? Other

			 * filesystems (IB, configfs) release dcache_lock

			 * before unlink */

			spin_unlock(&dcache_lock);

			dput(dentry);

		} else {

drivers/usb/core/inode.c

+3 −0
Original line number Diff line number Diff line
@@ -347,10 +347,13 @@ static int usbfs_empty (struct dentry *dentry) 


	list_for_each(list, &dentry->d_subdirs) {

		struct dentry *de = list_entry(list, struct dentry, d_u.d_child);

		spin_lock(&de->d_lock);

		if (usbfs_positive(de)) {

			spin_unlock(&de->d_lock);

			spin_unlock(&dcache_lock);

			return 0;

		}

		spin_unlock(&de->d_lock);

	}



	spin_unlock(&dcache_lock);

fs/autofs4/autofs_i.h

+0 −13
Original line number Diff line number Diff line
@@ -254,19 +254,6 @@ static inline int simple_positive(struct dentry *dentry) 
	return dentry->d_inode && !d_unhashed(dentry);

}



static inline int __simple_empty(struct dentry *dentry)

{

	struct dentry *child;

	int ret = 0;



	list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)

		if (simple_positive(child))

			goto out;

	ret = 1;

out:

	return ret;

}



static inline void autofs4_add_expiring(struct dentry *dentry)

{

	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);

fs/autofs4/expire.c

+16 −5
Original line number Diff line number Diff line
@@ -160,14 +160,18 @@ static int autofs4_tree_busy(struct vfsmount *mnt, 


	spin_lock(&dcache_lock);

	for (p = top; p; p = next_dentry(p, top)) {

		spin_lock(&p->d_lock);

		/* Negative dentry - give up */

		if (!simple_positive(p))

		if (!simple_positive(p)) {

			spin_unlock(&p->d_lock);

			continue;

		}



		DPRINTK("dentry %p %.*s",

			p, (int) p->d_name.len, p->d_name.name);



		p = dget(p);

		p = dget_dlock(p);

		spin_unlock(&p->d_lock);

		spin_unlock(&dcache_lock);



		/*
@@ -228,14 +232,18 @@ static struct dentry *autofs4_check_leaves(struct vfsmount *mnt, 


	spin_lock(&dcache_lock);

	for (p = parent; p; p = next_dentry(p, parent)) {

		spin_lock(&p->d_lock);

		/* Negative dentry - give up */

		if (!simple_positive(p))

		if (!simple_positive(p)) {

			spin_unlock(&p->d_lock);

			continue;

		}



		DPRINTK("dentry %p %.*s",

			p, (int) p->d_name.len, p->d_name.name);



		p = dget(p);

		p = dget_dlock(p);

		spin_unlock(&p->d_lock);

		spin_unlock(&dcache_lock);



		if (d_mountpoint(p)) {
@@ -324,12 +332,15 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb, 
		struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);



		/* Negative dentry - give up */

		spin_lock(&dentry->d_lock);

		if (!simple_positive(dentry)) {

			next = next->next;

			spin_unlock(&dentry->d_lock);

			continue;

		}



		dentry = dget(dentry);

		dentry = dget_dlock(dentry);

		spin_unlock(&dentry->d_lock);

		spin_unlock(&dcache_lock);



		spin_lock(&sbi->fs_lock);

fs/ceph/dir.c

+3 −2
Original line number Diff line number Diff line
@@ -136,6 +136,7 @@ static int __dcache_readdir(struct file *filp, 
			fi->at_end = 1;

			goto out_unlock;

		}

		spin_lock(&dentry->d_lock);

		if (!d_unhashed(dentry) && dentry->d_inode &&

		    ceph_snap(dentry->d_inode) != CEPH_SNAPDIR &&

		    ceph_ino(dentry->d_inode) != CEPH_INO_CEPH &&
@@ -145,13 +146,13 @@ static int __dcache_readdir(struct file *filp, 
		     dentry->d_name.len, dentry->d_name.name, di->offset,

		     filp->f_pos, d_unhashed(dentry) ? " unhashed" : "",

		     !dentry->d_inode ? " null" : "");

		spin_unlock(&dentry->d_lock);

		p = p->prev;

		dentry = list_entry(p, struct dentry, d_u.d_child);

		di = ceph_dentry(dentry);

	}



	spin_lock(&dentry->d_lock);

	dentry->d_count++;

	dget_dlock(dentry);

	spin_unlock(&dentry->d_lock);

	spin_unlock(&dcache_lock);