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authorSage Weil <sage@newdream.net>2011-07-26 22:30:55 +0400
committerSage Weil <sage@newdream.net>2011-07-26 22:30:55 +0400
commite5f86dc377e7ff2b4195831153a85a3e76fefff2 (patch)
treef15c11fc2c9b08e64555bbb601e582dc8f7325bd /fs/ceph
parentbf1c6aca96c9d2f117dc7e590c2bc2304e7febe1 (diff)
downloadlinux-e5f86dc377e7ff2b4195831153a85a3e76fefff2.tar.xz
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 <yehuda@hq.newdream.net> Signed-off-by: Sage Weil <sage@newdream.net>
Diffstat (limited to 'fs/ceph')
-rw-r--r--fs/ceph/dir.c3
-rw-r--r--fs/ceph/export.c24
-rw-r--r--fs/ceph/mds_client.c2
-rw-r--r--fs/ceph/super.h2
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);
/*