From e5f86dc377e7ff2b4195831153a85a3e76fefff2 Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Tue, 26 Jul 2011 11:30:55 -0700 Subject: [PATCH] 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: Yehuda Sadeh Signed-off-by: Sage Weil --- fs/ceph/dir.c | 3 +-- fs/ceph/export.c | 24 +++++++++++++++--------- fs/ceph/mds_client.c | 2 +- fs/ceph/super.h | 2 +- 4 files changed, 18 insertions(+), 13 deletions(-) diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c index 31d27f8f8261..33a19df72288 100644 --- a/fs/ceph/dir.c +++ b/fs/ceph/dir.c @@ -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) { diff --git a/fs/ceph/export.c b/fs/ceph/export.c index f67b687550de..9fbcdecaaccd 100644 --- a/fs/ceph/export.c +++ b/fs/ceph/export.c @@ -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; } - 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); diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 3b1e743b8c8d..8a09cd5a659e 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -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; } } diff --git a/fs/ceph/super.h b/fs/ceph/super.h index c1eb9a014b74..35dc9656e499 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -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); /* -- 2.34.1