Commit 1ffe46d1 authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Al Viro
Browse files

vfs: Merge check_submounts_and_drop and d_invalidate 



Now that d_invalidate is the only caller of check_submounts_and_drop,
expand check_submounts_and_drop inline in d_invalidate.

Reviewed-by: default avatarMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 9b053f32

fs/dcache.c

+22 −33
Original line number Diff line number Diff line
@@ -645,32 +645,6 @@ void dput(struct dentry *dentry) 
}

EXPORT_SYMBOL(dput);



/**

 * d_invalidate - invalidate a dentry

 * @dentry: dentry to invalidate

 *

 * Try to invalidate the dentry if it turns out to be

 * possible. If there are reasons not to delete it

 * return -EBUSY. On success return 0.

 *

 * no dcache lock.

 */

 

int d_invalidate(struct dentry * dentry)

{

	/*

	 * If it's already been dropped, return OK.

	 */

	spin_lock(&dentry->d_lock);

	if (d_unhashed(dentry)) {

		spin_unlock(&dentry->d_lock);

		return 0;

	}

	spin_unlock(&dentry->d_lock);



	return check_submounts_and_drop(dentry);

}

EXPORT_SYMBOL(d_invalidate);



/* This must be called with d_lock held */

static inline void __dget_dlock(struct dentry *dentry)
@@ -1190,7 +1164,7 @@ EXPORT_SYMBOL(have_submounts); 
 * reachable (e.g. NFS can unhash a directory dentry and then the complete

 * subtree can become unreachable).

 *

 * Only one of check_submounts_and_drop() and d_set_mounted() must succeed.  For

 * Only one of d_invalidate() and d_set_mounted() must succeed.  For

 * this reason take rename_lock and d_lock on dentry and ancestors.

 */

int d_set_mounted(struct dentry *dentry)
@@ -1199,7 +1173,7 @@ int d_set_mounted(struct dentry *dentry) 
	int ret = -ENOENT;

	write_seqlock(&rename_lock);

	for (p = dentry->d_parent; !IS_ROOT(p); p = p->d_parent) {

		/* Need exclusion wrt. check_submounts_and_drop() */

		/* Need exclusion wrt. d_invalidate() */

		spin_lock(&p->d_lock);

		if (unlikely(d_unhashed(p))) {

			spin_unlock(&p->d_lock);
@@ -1369,18 +1343,33 @@ static void check_and_drop(void *_data) 
}



/**

 * check_submounts_and_drop - detach submounts, prune dcache, and drop

 * d_invalidate - detach submounts, prune dcache, and drop

 * @dentry: dentry to invalidate (aka detach, prune and drop)

 *

 * Try to invalidate the dentry if it turns out to be

 * possible. If there are reasons not to delete it

 * return -EBUSY. On success return 0.

 *

 * no dcache lock.

 *

 * The final d_drop is done as an atomic operation relative to

 * rename_lock ensuring there are no races with d_set_mounted.  This

 * ensures there are no unhashed dentries on the path to a mountpoint.

 *

 * @dentry: dentry to detach, prune and drop

 */

int check_submounts_and_drop(struct dentry *dentry)

int d_invalidate(struct dentry *dentry)

{

	int ret = 0;



	/*

	 * If it's already been dropped, return OK.

	 */

	spin_lock(&dentry->d_lock);

	if (d_unhashed(dentry)) {

		spin_unlock(&dentry->d_lock);

		return 0;

	}

	spin_unlock(&dentry->d_lock);



	/* Negative dentries can be dropped without further checks */

	if (!dentry->d_inode) {

		d_drop(dentry);
@@ -1414,7 +1403,7 @@ int check_submounts_and_drop(struct dentry *dentry) 
out:

	return ret;

}

EXPORT_SYMBOL(check_submounts_and_drop);

EXPORT_SYMBOL(d_invalidate);



/**

 * __d_alloc	-	allocate a dcache entry

include/linux/dcache.h

+0 −1
Original line number Diff line number Diff line
@@ -269,7 +269,6 @@ extern void d_prune_aliases(struct inode *); 


/* test whether we have any submounts in a subdir tree */

extern int have_submounts(struct dentry *);

extern int check_submounts_and_drop(struct dentry *);



/*

 * This adds the entry to the hash queues.