Commit e5f86dc3 authored by Sage Weil's avatar Sage Weil
Browse files

ceph: avoid d_parent in ceph_dentry_hash; fix ceph_encode_fh() hashing bug 



Have caller pass in a safely-obtained reference to the parent directory
for calculating a dentry's hash valud.

While we're here, simpify the flow through ceph_encode_fh() so that there
is a single exit point and cleanup.

Also fix a bug with the dentry hash calculation: calculate the hash for the
dentry we were given, not its parent.

Reviewed-by: default avatarYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: default avatarSage Weil <sage@newdream.net>
parent bf1c6aca

fs/ceph/dir.c

+1 −2
Original line number Diff line number Diff line
@@ -1244,9 +1244,8 @@ void ceph_dentry_lru_del(struct dentry *dn) 
 * Return name hash for a given dentry.  This is dependent on

 * the parent directory's hash function.

 */

unsigned ceph_dentry_hash(struct dentry *dn)

unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)

{

	struct inode *dir = dn->d_parent->d_inode;

	struct ceph_inode_info *dci = ceph_inode(dir);



	switch (dci->i_dir_layout.dl_dir_hash) {

fs/ceph/export.c

+15 −9
Original line number Diff line number Diff line
@@ -46,7 +46,7 @@ static int ceph_encode_fh(struct dentry *dentry, u32 *rawfh, int *max_len, 
	int type;

	struct ceph_nfs_fh *fh = (void *)rawfh;

	struct ceph_nfs_confh *cfh = (void *)rawfh;

	struct dentry *parent = dentry->d_parent;

	struct dentry *parent;

	struct inode *inode = dentry->d_inode;

	int connected_handle_length = sizeof(*cfh)/4;

	int handle_length = sizeof(*fh)/4;
@@ -55,26 +55,33 @@ static int ceph_encode_fh(struct dentry *dentry, u32 *rawfh, int *max_len, 
	if (ceph_snap(inode) != CEPH_NOSNAP)

		return -EINVAL;



	spin_lock(&dentry->d_lock);

	parent = dget(dentry->d_parent);

	spin_unlock(&dentry->d_lock);



	if (*max_len >= connected_handle_length) {

		dout("encode_fh %p connectable\n", dentry);

		cfh->ino = ceph_ino(dentry->d_inode);

		cfh->parent_ino = ceph_ino(parent->d_inode);

		cfh->parent_name_hash = ceph_dentry_hash(parent);

		cfh->parent_name_hash = ceph_dentry_hash(parent->d_inode,

							 dentry);

		*max_len = connected_handle_length;

		type = 2;

	} else if (*max_len >= handle_length) {

		if (connectable) {

			*max_len = connected_handle_length;

			return 255;

		}

			type = 255;

		} else {

			dout("encode_fh %p\n", dentry);

			fh->ino = ceph_ino(dentry->d_inode);

			*max_len = handle_length;

			type = 1;

		}

	} else {

		*max_len = handle_length;

		return 255;

		type = 255;

	}

	dput(parent);

	return type;

}
@@ -123,7 +130,6 @@ static struct dentry *__fh_to_dentry(struct super_block *sb, 
		return dentry;

	}

	err = ceph_init_dentry(dentry);



	if (err < 0) {

		iput(inode);

		return ERR_PTR(err);

fs/ceph/mds_client.c

+1 −1
Original line number Diff line number Diff line
@@ -670,7 +670,7 @@ static int __choose_mds(struct ceph_mds_client *mdsc, 
		} else {

			/* dir + name */

			inode = dir;

			hash = ceph_dentry_hash(req->r_dentry);

			hash = ceph_dentry_hash(dir, req->r_dentry);

			is_hash = true;

		}

	}

fs/ceph/super.h

+1 −1
Original line number Diff line number Diff line
@@ -800,7 +800,7 @@ extern void ceph_dentry_lru_add(struct dentry *dn); 
extern void ceph_dentry_lru_touch(struct dentry *dn);

extern void ceph_dentry_lru_del(struct dentry *dn);

extern void ceph_invalidate_dentry_lease(struct dentry *dentry);

extern unsigned ceph_dentry_hash(struct dentry *dn);

extern unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn);

extern struct inode *ceph_get_dentry_parent_inode(struct dentry *dentry);



/*

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