features/bit-rot-stub: fail the fop if inode context get fails

In stub, for fops like readv, writev etc, if the the object is bad, then the fop
is denied. But for checking if the object is bad inode context should be
checked. Now, if the inode context is not there, then the fop is allowed to
continue. This patch fixes it and the fop is unwound with an error, if the inode
context is not found.

Change-Id: I5ea4d4fc1a91387f7f9d13ca8cb43c88429f02b0
BUG: 1243391
Signed-off-by: Raghavendra Bhat <raghavendra@redhat.com>
Reviewed-on: http://review.gluster.org/11449
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Venky Shankar <vshankar@redhat.com>

2 files changed, 96 insertions, 23 deletions

diff --git a/xlators/features/bit-rot/src/stub/bit-rot-stub.c b/xlators/features/bit-rot/src/stub/bit-rot-stub.c
index f30b5a74307..9439f0cdfe7 100644
--- a/xlators/features/bit-rot/src/stub/bit-rot-stub.c
+++ b/xlators/features/bit-rot/src/stub/bit-rot-stub.c
@@ -452,6 +452,40 @@ br_stub_mark_inode_modified (xlator_t *this, br_stub_local_t *local)
 }
 
 /**
+ * The possible return values from br_stub_is_bad_object () are:
+ * 1) 0  => as per the inode context object is not bad
+ * 2) -1 => Failed to get the inode context itself
+ * 3) -2 => As per the inode context object is bad
+ * Both -ve values means the fop which called this function is failed
+ * and error is returned upwards.
+ */
+static int
+br_stub_check_bad_object (xlator_t *this, inode_t *inode, int32_t *op_ret,
+                           int32_t *op_errno)
+{
+        int ret = -1;
+
+        ret = br_stub_is_bad_object (this, inode);
+        if (ret == -2) {
+                gf_msg (this->name, GF_LOG_ERROR, 0, BRS_MSG_BAD_OBJECT_ACCESS,
+                        "%s is a bad object. Returning",
+                        uuid_utoa (inode->gfid));
+                *op_ret = -1;
+                *op_errno = EIO;
+        }
+
+        if (ret == -1) {
+                gf_msg (this->name, GF_LOG_ERROR, 0,
+                        BRS_MSG_GET_INODE_CONTEXT_FAILED, "could not get inode"
+                        " context for %s", uuid_utoa (inode->gfid));
+                *op_ret = -1;
+                *op_errno = EINVAL;
+        }
+
+        return ret;
+}
+
+/**
  * callback for inode/fd versioning
  */
 int
@@ -1095,6 +1129,12 @@ br_stub_fsetxattr (call_frame_t *frame, xlator_t *this,
                 goto done;
         }
 
+        if (dict_get (dict, GLUSTERFS_GET_OBJECT_SIGNATURE)) {
+                br_stub_handle_internal_xattr (frame, this, fd,
+                                               GLUSTERFS_GET_OBJECT_SIGNATURE);
+                goto done;
+        }
+
         /* object reopen request */
         ret = dict_get_uint32 (dict, BR_REOPEN_SIGN_HINT_KEY, &val);
         if (!ret) {
@@ -1135,6 +1175,7 @@ br_stub_setxattr (call_frame_t *frame, xlator_t *this,
         char    *format                    = "(%s:%s)";
 
         if (dict_get (dict, GLUSTERFS_SET_OBJECT_SIGNATURE) ||
+            dict_get (dict, GLUSTERFS_GET_OBJECT_SIGNATURE) ||
             dict_get (dict, BR_REOPEN_SIGN_HINT_KEY) ||
             dict_get (dict, BITROT_OBJECT_BAD_KEY) ||
             dict_get (dict, BITROT_SIGNING_VERSION_KEY) ||
@@ -1579,13 +1620,16 @@ br_stub_readv (call_frame_t *frame, xlator_t *this,
 {
         int32_t              op_ret   = -1;
         int32_t              op_errno = EINVAL;
+        int32_t              ret      = -1;
 
         GF_VALIDATE_OR_GOTO ("bit-rot-stub", this, unwind);
         GF_VALIDATE_OR_GOTO (this->name, frame, unwind);
         GF_VALIDATE_OR_GOTO (this->name, fd, unwind);
         GF_VALIDATE_OR_GOTO (this->name, fd->inode, unwind);
 
-        BR_STUB_HANDLE_BAD_OBJECT (this, fd->inode, op_ret, op_errno, unwind);
+        ret = br_stub_check_bad_object (this, fd->inode, &op_ret, &op_errno);
+        if (ret)
+                goto unwind;
 
         STACK_WIND_TAIL (frame, FIRST_CHILD(this),
                          FIRST_CHILD(this)->fops->readv, fd, size, offset,
@@ -1679,7 +1723,9 @@ br_stub_writev (call_frame_t *frame, xlator_t *this, fd_t *fd,
         if (ret)
                 goto unwind;
 
-        BR_STUB_HANDLE_BAD_OBJECT (this, fd->inode, op_ret, op_errno, unwind);
+        ret = br_stub_check_bad_object (this, fd->inode, &op_ret, &op_errno);
+        if (ret)
+                goto unwind;
 
         /**
          * The inode is not dirty and also witnessed atleast one successful
@@ -1800,7 +1846,9 @@ br_stub_ftruncate (call_frame_t *frame, xlator_t *this, fd_t *fd,
         if (ret)
                 goto unwind;
 
-        BR_STUB_HANDLE_BAD_OBJECT (this, fd->inode, op_ret, op_errno, unwind);
+        ret = br_stub_check_bad_object (this, fd->inode, &op_ret, &op_errno);
+        if (ret)
+                goto unwind;
 
         if (!inc_version && modified)
                 goto wind;
@@ -1932,7 +1980,9 @@ br_stub_truncate (call_frame_t *frame, xlator_t *this, loc_t *loc,
         if (ret)
                 goto cleanup_fd;
 
-        BR_STUB_HANDLE_BAD_OBJECT (this, fd->inode, op_ret, op_errno, unwind);
+        ret = br_stub_check_bad_object (this, fd->inode, &op_ret, &op_errno);
+        if (ret)
+                goto unwind;
 
         if (!inc_version && modified)
                 goto wind;
@@ -2026,7 +2076,9 @@ br_stub_open (call_frame_t *frame, xlator_t *this,
 
         ctx = (br_stub_inode_ctx_t *)(long)ctx_addr;
 
-        BR_STUB_HANDLE_BAD_OBJECT (this, loc->inode, op_ret, op_errno, unwind);
+        ret = br_stub_check_bad_object (this, fd->inode, &op_ret, &op_errno);
+        if (ret)
+                goto unwind;
 
         if (frame->root->pid == GF_CLIENT_PID_SCRUB)
                 goto wind;
@@ -2208,6 +2260,13 @@ unwind:
  * calls can be avoided and bad objects can be caught instantly. Fetching the
  * xattr is needed only in lookups when there is a brick restart or inode
  * forget.
+ *
+ * If the dict (@xattr) is NULL, then how should that be handled? Fail the
+ * lookup operation? Or let it continue with version being initialized to
+ * BITROT_DEFAULT_CURRENT_VERSION. But what if the version was different
+ * on disk (and also a right signature was there), but posix failed to
+ * successfully allocate the dict? Posix does not treat call back xdata
+ * creattion failure as the lookup failure.
  */
 static inline int32_t
 br_stub_lookup_version (xlator_t *this,
@@ -2232,6 +2291,14 @@ br_stub_lookup_version (xlator_t *this,
                    || (status == BR_VXATTR_STATUS_UNSIGNED))
                         ? obuf->ongoingversion : BITROT_DEFAULT_CURRENT_VERSION;
 
+        /**
+         * If signature is there, but version is not therem then that status is
+         * is treated as INVALID. So in that case, we should not initialize the
+         * inode context with wrong version names etc.
+         */
+        if (status == BR_VXATTR_STATUS_INVALID)
+                return -1;
+
         return br_stub_init_inode_versions (this, NULL, inode, version,
                                             _gf_true, bad_object);
 }
diff --git a/xlators/features/bit-rot/src/stub/bit-rot-stub.h b/xlators/features/bit-rot/src/stub/bit-rot-stub.h
index c8442068e6b..9362c129303 100644
--- a/xlators/features/bit-rot/src/stub/bit-rot-stub.h
+++ b/xlators/features/bit-rot/src/stub/bit-rot-stub.h
@@ -385,32 +385,32 @@ br_stub_remove_vxattrs (dict_t *xattr)
         }
 }
 
-#define BR_STUB_HANDLE_BAD_OBJECT(this, inode, op_ret, op_errno, label) \
-        do {                                                            \
-                if (br_stub_is_bad_object (this, inode)) {              \
-                        gf_msg (this->name, GF_LOG_ERROR, 0,            \
-                                 BRS_MSG_BAD_OBJECT_ACCESS,             \
-                                 "%s is a bad object. Returning",       \
-                                 uuid_utoa (inode->gfid));              \
-                        op_ret = -1;                                    \
-                        op_errno = EIO;                                 \
-                        goto label;                                     \
-                }                                                       \
-        } while (0)
-
-static inline gf_boolean_t
+/**
+ * This function returns the below values for different situations
+ * 0  => as per the inode context object is not bad
+ * -1 => Failed to get the inode context itself
+ * -2 => As per the inode context object is bad
+ * Both -ve values means the fop which called this function is failed
+ * and error is returned upwards.
+ * In future if needed or more errors have to be handled, then those
+ * errors can be made into enums.
+ */
+static inline int
 br_stub_is_bad_object (xlator_t *this, inode_t *inode)
 {
-        gf_boolean_t         bad_object = _gf_false;
+        int                  bad_object = 0;
+        gf_boolean_t         tmp        = _gf_false;
         uint64_t             ctx_addr   = 0;
         br_stub_inode_ctx_t *ctx        = NULL;
         int32_t              ret        = -1;
 
         ret = br_stub_get_inode_ctx (this, inode, &ctx_addr);
         if (ret) {
-                gf_msg (this->name, GF_LOG_ERROR, 0, BRS_MSG_SET_CONTEXT_FAILED,
+                gf_msg (this->name, GF_LOG_ERROR, 0,
+                        BRS_MSG_GET_INODE_CONTEXT_FAILED,
                         "failed to get the inode context for the inode %s",
                         uuid_utoa (inode->gfid));
+                bad_object = -1;
                 goto out;
         }
 
@@ -418,7 +418,9 @@ br_stub_is_bad_object (xlator_t *this, inode_t *inode)
 
         LOCK (&inode->lock);
         {
-                bad_object = __br_stub_is_bad_object (ctx);
+                tmp = __br_stub_is_bad_object (ctx);
+                if (tmp)
+                        bad_object = -2;
         }
         UNLOCK (&inode->lock);
 
@@ -454,12 +456,16 @@ out:
         return ret;
 }
 
+/**
+ * There is a possibility that dict_set might fail. The o/p of dict_set is
+ * given to the caller and the caller has to decide what to do.
+ */
 static inline int32_t
 br_stub_mark_xdata_bad_object (xlator_t *this, inode_t *inode, dict_t *xdata)
 {
         int32_t    ret = 0;
 
-        if (br_stub_is_bad_object (this, inode))
+        if (br_stub_is_bad_object (this, inode) == -2)
                 ret = dict_set_int32 (xdata, GLUSTERFS_BAD_INODE, 1);
 
         return ret;