storage/posix: send proper iatt attributes for the root inode

* changes in posix to send proper iatt attributes for the root directory
  when ancestry is built. Before posix was filling only the gfid and the
  inode type in the iatt structure keeping rest of the fields zeros. This
  was cached by posix-acl and used to send EACCES when some fops came on
  that object if the uid of the caller is same as the uid of the object on
  the disk.

* getting and setting inode_ctx in function 'posix_acl_ctx_get' is not atomic
  and can lead to memory leak when there are multiple looups for an
  inode at same time. This patch fix this problem

* Linking an inode in posix_build_ancestry, can cause a race in
  posix_acl.
  When parent inode is linked in posix_build_ancestry, and before
  it reaches posix_acl_readdirp_cbkc, reate/lookup can
  come on a leaf-inode, as parent-inode-ctx not yet updated
  in posix_acl_readdirp_cbk, create/lookup can fail
  with EACCESS. So do the inode linking in the quota xlator

Change-Id: I3101eefb65551cc4162c4ff2963be1b73deacd6d
BUG: 1320818
Signed-off-by: Raghavendra Bhat <raghavendra@redhat.com>
Reviewed-on: http://review.gluster.org/13730
Tested-by: Vijaikumar Mallikarjuna <vmallika@redhat.com>
Smoke: Gluster Build System <jenkins@build.gluster.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>

1 files changed, 46 insertions, 12 deletions

diff --git a/xlators/system/posix-acl/src/posix-acl.c b/xlators/system/posix-acl/src/posix-acl.c
index 2edaa408135..61d2d6647f6 100644
--- a/xlators/system/posix-acl/src/posix-acl.c
+++ b/xlators/system/posix-acl/src/posix-acl.c
@@ -193,8 +193,12 @@ acl_permits (call_frame_t *frame, inode_t *inode, int want)
         conf = frame->this->private;
 
         ctx = posix_acl_ctx_get (inode, frame->this);
-        if (!ctx)
+        if (!ctx) {
+                gf_log_callingfn (frame->this->name, GF_LOG_ERROR,
+                                  "inode ctx is NULL for %s",
+                                  uuid_utoa (inode->gfid));
                 goto red;
+        }
 
         if (frame_is_super_user (frame))
                 goto green;
@@ -287,21 +291,52 @@ out:
 
 
 struct posix_acl_ctx *
-posix_acl_ctx_get (inode_t *inode, xlator_t *this)
+__posix_acl_ctx_get (inode_t *inode, xlator_t *this, gf_boolean_t create)
 {
         struct posix_acl_ctx *ctx = NULL;
         uint64_t              int_ctx = 0;
         int                   ret = 0;
 
-        ret = inode_ctx_get (inode, this, &int_ctx);
+        ret = __inode_ctx_get (inode, this, &int_ctx);
         if ((ret == 0) && (int_ctx))
                 return PTR(int_ctx);
 
+        if (create == _gf_false)
+                return NULL;
+
         ctx = GF_CALLOC (1, sizeof (*ctx), gf_posix_acl_mt_ctx_t);
         if (!ctx)
                 return NULL;
 
-        ret = inode_ctx_put (inode, this, UINT64 (ctx));
+        ret = __inode_ctx_put (inode, this, UINT64 (ctx));
+
+        return ctx;
+}
+
+struct posix_acl_ctx *
+posix_acl_ctx_new (inode_t *inode, xlator_t *this)
+{
+        struct posix_acl_ctx *ctx = NULL;
+
+        LOCK (&inode->lock);
+        {
+                ctx = __posix_acl_ctx_get (inode, this, _gf_true);
+        }
+        UNLOCK (&inode->lock);
+
+        return ctx;
+}
+
+struct posix_acl_ctx *
+posix_acl_ctx_get (inode_t *inode, xlator_t *this)
+{
+        struct posix_acl_ctx *ctx = NULL;
+
+        LOCK (&inode->lock);
+        {
+                ctx = __posix_acl_ctx_get (inode, this, _gf_false);
+        }
+        UNLOCK (&inode->lock);
 
         return ctx;
 }
@@ -636,7 +671,7 @@ posix_acl_inherit (xlator_t *this, loc_t *loc, dict_t *params, mode_t mode,
         if (!par_default)
                 goto out;
 
-        ctx = posix_acl_ctx_get (loc->inode, this);
+        ctx = posix_acl_ctx_new (loc->inode, this);
 
         acl_access = posix_acl_dup (this, par_default);
         if (!acl_access)
@@ -742,14 +777,14 @@ posix_acl_ctx_update (inode_t *inode, xlator_t *this, struct iatt *buf)
         int                   ret = 0;
 	int                   i = 0;
 
-        ctx = posix_acl_ctx_get (inode, this);
-        if (!ctx) {
-                ret = -1;
-                goto out;
-        }
-
         LOCK(&inode->lock);
         {
+                ctx = __posix_acl_ctx_get (inode, this, _gf_true);
+                if (!ctx) {
+                        ret = -1;
+                        goto unlock;
+                }
+
                 ctx->uid   = buf->ia_uid;
                 ctx->gid   = buf->ia_gid;
                 ctx->perm  = st_mode_from_ia (buf->ia_prot, buf->ia_type);
@@ -794,7 +829,6 @@ posix_acl_ctx_update (inode_t *inode, xlator_t *this, struct iatt *buf)
         }
 unlock:
         UNLOCK(&inode->lock);
-out:
         return ret;
 }