[v2,3/4] ceph: ensure d_name stability in ceph_dentry_hash
diff mbox series

Message ID 20190417183959.11296-4-jlayton@kernel.org
State New
Headers show
Series
  • ceph: dentry->d_name handing fixes
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Commit Message

Jeff Layton April 17, 2019, 6:39 p.m. UTC
Take the d_lock here to ensure that d_name doesn't change.

Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/ceph/dir.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Comments

Yan, Zheng April 18, 2019, 2:40 a.m. UTC | #1
On Thu, Apr 18, 2019 at 2:43 AM Jeff Layton <jlayton@kernel.org> wrote:
>
> Take the d_lock here to ensure that d_name doesn't change.
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
>  fs/ceph/dir.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
> index a8f429882249..0637149fb9f9 100644
> --- a/fs/ceph/dir.c
> +++ b/fs/ceph/dir.c
> @@ -1766,6 +1766,7 @@ static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
>  unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
>  {
>         struct ceph_inode_info *dci = ceph_inode(dir);
> +       unsigned hash;
>
>         switch (dci->i_dir_layout.dl_dir_hash) {
>         case 0: /* for backward compat */
> @@ -1773,8 +1774,11 @@ unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
>                 return dn->d_name.hash;
>
>         default:
> -               return ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
> +               spin_lock(&dn->d_lock);
> +               hash = ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
>                                      dn->d_name.name, dn->d_name.len);
> +               spin_unlock(&dn->d_lock);
> +               return hash;
>         }
>  }
>
> --
> 2.20.1
>

Reviewed-by: "Yan, Zheng" <zyan@redhat.com>

Patch
diff mbox series

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index a8f429882249..0637149fb9f9 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -1766,6 +1766,7 @@  static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
 unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
 {
 	struct ceph_inode_info *dci = ceph_inode(dir);
+	unsigned hash;
 
 	switch (dci->i_dir_layout.dl_dir_hash) {
 	case 0:	/* for backward compat */
@@ -1773,8 +1774,11 @@  unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
 		return dn->d_name.hash;
 
 	default:
-		return ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
+		spin_lock(&dn->d_lock);
+		hash = ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
 				     dn->d_name.name, dn->d_name.len);
+		spin_unlock(&dn->d_lock);
+		return hash;
 	}
 }