LU-6027 osd-zfs: Preserve lu_buf when listing EAs

Current osd_xattr_list() in osd-zfs modifies its lu_buf argument,
leaving lu_buf::lb_buf pointing to the end of the original buffer.
This behavior is unnecessary and counter-intuitive.  This patch
preserves the content of the lu_buf argument and updates OSD API to
reduce the chance of future regressions.

Change-Id: I0d3e334848734ca6f44778e87b5ff3b044826784
Signed-off-by: Li Wei <wei.g.li@intel.com>
Reviewed-on: http://review.whamcloud.com/12880
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Johann Lombardi <johann.lombardi@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>

diff --git a/lustre/include/dt_object.h b/lustre/include/dt_object.h
index a54157e..b605250 100644 (file)
--- a/lustre/include/dt_object.h
+++ b/lustre/include/dt_object.h
@@ -743,7 +743,7 @@ struct dt_object_operations {
          */
        int   (*do_xattr_list)(const struct lu_env *env,
                               struct dt_object *dt,
-                              struct lu_buf *buf,
+                              const struct lu_buf *buf,
                               struct lustre_capa *capa);
 
        /**
@@ -2622,9 +2622,9 @@ static inline int dt_xattr_get(const struct lu_env *env,
         return dt->do_ops->do_xattr_get(env, dt, buf, name, capa);
 }
 
-static inline int dt_xattr_list(const struct lu_env *env,
-                               struct dt_object *dt, struct lu_buf *buf,
-                               struct lustre_capa *capa)
+static inline int dt_xattr_list(const struct lu_env *env, struct dt_object *dt,
+                               const struct lu_buf *buf,
+                               struct lustre_capa *capa)
 {
         LASSERT(dt);
         LASSERT(dt->do_ops);

diff --git a/lustre/lod/lod_object.c b/lustre/lod/lod_object.c
index 086b93c..dba607c 100644 (file)
--- a/lustre/lod/lod_object.c
+++ b/lustre/lod/lod_object.c
@@ -2829,7 +2829,7 @@ static int lod_xattr_del(const struct lu_env *env, struct dt_object *dt,
  * for details.
  */
 static int lod_xattr_list(const struct lu_env *env,
-                         struct dt_object *dt, struct lu_buf *buf,
+                         struct dt_object *dt, const struct lu_buf *buf,
                          struct lustre_capa *capa)
 {
        return dt_xattr_list(env, dt_object_child(dt), buf, capa);

diff --git a/lustre/osd-ldiskfs/osd_handler.c b/lustre/osd-ldiskfs/osd_handler.c
index e26fb73..af1eb5d 100644 (file)
--- a/lustre/osd-ldiskfs/osd_handler.c
+++ b/lustre/osd-ldiskfs/osd_handler.c
@@ -3087,7 +3087,7 @@ static int osd_xattr_set(const struct lu_env *env, struct dt_object *dt,
  * Concurrency: @dt is read locked.
  */
 static int osd_xattr_list(const struct lu_env *env, struct dt_object *dt,
-                         struct lu_buf *buf, struct lustre_capa *capa)
+                         const struct lu_buf *buf, struct lustre_capa *capa)
 {
        struct osd_object      *obj    = osd_dt_obj(dt);
        struct inode           *inode  = obj->oo_inode;

diff --git a/lustre/osd-zfs/osd_internal.h b/lustre/osd-zfs/osd_internal.h
index 9bb7f98..40cba11 100644 (file)
--- a/lustre/osd-zfs/osd_internal.h
+++ b/lustre/osd-zfs/osd_internal.h
@@ -490,7 +490,7 @@ int osd_xattr_del(const struct lu_env *env, struct dt_object *dt,
                  const char *name, struct thandle *handle,
                  struct lustre_capa *capa);
 int osd_xattr_list(const struct lu_env *env, struct dt_object *dt,
-                  struct lu_buf *lb, struct lustre_capa *capa);
+                  const struct lu_buf *lb, struct lustre_capa *capa);
 void __osd_xattr_declare_set(const struct lu_env *env, struct osd_object *obj,
                        int vallen, const char *name, struct osd_thandle *oh);
 int __osd_sa_xattr_set(const struct lu_env *env, struct osd_object *obj,

diff --git a/lustre/osd-zfs/osd_xattr.c b/lustre/osd-zfs/osd_xattr.c
index b20a2aa..6657237 100644 (file)
--- a/lustre/osd-zfs/osd_xattr.c
+++ b/lustre/osd-zfs/osd_xattr.c
@@ -758,10 +758,10 @@ int osd_xattr_del(const struct lu_env *env, struct dt_object *dt,
 
 static int
 osd_sa_xattr_list(const struct lu_env *env, struct osd_object *obj,
-                 struct lu_buf *lb)
+                 const struct lu_buf *lb)
 {
        nvpair_t *nvp = NULL;
-       int       len, counted = 0, remain = lb->lb_len;
+       int       len, counted = 0;
        int       rc = 0;
 
        if (obj->oo_sa_xattr == NULL) {
@@ -780,16 +780,12 @@ osd_sa_xattr_list(const struct lu_env *env, struct osd_object *obj,
                     strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0))
                        continue;
 
-               len = strlen(nvpair_name(nvp));
+               len = strlen(name);
                if (lb->lb_buf != NULL) {
-                       if (len + 1 > remain)
+                       if (counted + len + 1 > lb->lb_len)
                                return -ERANGE;
 
-                       memcpy(lb->lb_buf, name, len);
-                       lb->lb_buf += len;
-                       *((char *)lb->lb_buf) = '\0';
-                       lb->lb_buf++;
-                       remain -= len + 1;
+                       memcpy(lb->lb_buf + counted, name, len + 1);
                }
                counted += len + 1;
        }
@@ -797,13 +793,13 @@ osd_sa_xattr_list(const struct lu_env *env, struct osd_object *obj,
 }
 
 int osd_xattr_list(const struct lu_env *env, struct dt_object *dt,
-                  struct lu_buf *lb, struct lustre_capa *capa)
+                  const struct lu_buf *lb, struct lustre_capa *capa)
 {
        struct osd_object      *obj = osd_dt_obj(dt);
        struct osd_device      *osd = osd_obj2dev(obj);
        zap_attribute_t        *za = &osd_oti_get(env)->oti_za;
        zap_cursor_t           *zc;
-       int                    rc, counted = 0, remain = lb->lb_len;
+       int                    rc, counted;
        ENTRY;
 
        LASSERT(obj->oo_db != NULL);
@@ -815,8 +811,8 @@ int osd_xattr_list(const struct lu_env *env, struct dt_object *dt,
        rc = osd_sa_xattr_list(env, obj, lb);
        if (rc < 0)
                GOTO(out, rc);
+
        counted = rc;
-       remain -= counted;
 
        /* continue with dnode xattr if any */
        if (obj->oo_xattr == ZFS_NO_OBJECT)
@@ -836,14 +832,10 @@ int osd_xattr_list(const struct lu_env *env, struct dt_object *dt,
 
                rc = strlen(za->za_name);
                if (lb->lb_buf != NULL) {
-                       if (rc + 1 > remain)
+                       if (counted + rc + 1 > lb->lb_len)
                                RETURN(-ERANGE);
 
-                       memcpy(lb->lb_buf, za->za_name, rc);
-                       lb->lb_buf += rc;
-                       *((char *)lb->lb_buf) = '\0';
-                       lb->lb_buf++;
-                       remain -= rc + 1;
+                       memcpy(lb->lb_buf + counted, za->za_name, rc + 1);
                }
                counted += rc + 1;