ctime: Set mdata xattr on legacy files

Problem:
The files which were created before ctime enabled would not
have "trusted.glusterfs.mdata"(stores time attributes) xattr.
Upon fops which modifies either ctime or mtime, the xattr
gets created with latest ctime, mtime and atime, which is
incorrect. It should update only the corresponding time
attribute and rest from backend

Solution:
Creating xattr with values from brick is not possible as
each brick of replica set would have different times.
So create the xattr upon successful lookup if the xattr
is not created

Note To Reviewers:
The time attributes used to set xattr is got from successful
lookup. Instead of sending the whole iatt over the wire via
setxattr, a structure called mdata_iatt is sent. The mdata_iatt
contains only time attributes.

Backport of:
 > Patch:  https://review.gluster.org/22936
 > Change-Id: I5e535631ddef04195361ae0364336410a2895dd4
 > BUG: 1593542
 > Signed-off-by: Kotresh HR <khiremat@redhat.com>

Change-Id: I5e535631ddef04195361ae0364336410a2895dd4
updates: bz#1739430
Signed-off-by: Kotresh HR <khiremat@redhat.com>

1 files changed, 59 insertions, 0 deletions

diff --git a/rpc/xdr/src/glusterfs3.h b/rpc/xdr/src/glusterfs3.h
index 5521f4d4eca..86b3a4c0e5d 100644
--- a/rpc/xdr/src/glusterfs3.h
+++ b/rpc/xdr/src/glusterfs3.h
@@ -585,6 +585,34 @@ out:
 }
 
 static inline void
+gfx_mdata_iatt_to_mdata_iatt(struct gfx_mdata_iatt *gf_mdata_iatt,
+                             struct mdata_iatt *mdata_iatt)
+{
+    if (!mdata_iatt || !gf_mdata_iatt)
+        return;
+    mdata_iatt->ia_atime = gf_mdata_iatt->ia_atime;
+    mdata_iatt->ia_atime_nsec = gf_mdata_iatt->ia_atime_nsec;
+    mdata_iatt->ia_mtime = gf_mdata_iatt->ia_mtime;
+    mdata_iatt->ia_mtime_nsec = gf_mdata_iatt->ia_mtime_nsec;
+    mdata_iatt->ia_ctime = gf_mdata_iatt->ia_ctime;
+    mdata_iatt->ia_ctime_nsec = gf_mdata_iatt->ia_ctime_nsec;
+}
+
+static inline void
+gfx_mdata_iatt_from_mdata_iatt(struct gfx_mdata_iatt *gf_mdata_iatt,
+                               struct mdata_iatt *mdata_iatt)
+{
+    if (!mdata_iatt || !gf_mdata_iatt)
+        return;
+    gf_mdata_iatt->ia_atime = mdata_iatt->ia_atime;
+    gf_mdata_iatt->ia_atime_nsec = mdata_iatt->ia_atime_nsec;
+    gf_mdata_iatt->ia_mtime = mdata_iatt->ia_mtime;
+    gf_mdata_iatt->ia_mtime_nsec = mdata_iatt->ia_mtime_nsec;
+    gf_mdata_iatt->ia_ctime = mdata_iatt->ia_ctime;
+    gf_mdata_iatt->ia_ctime_nsec = mdata_iatt->ia_ctime_nsec;
+}
+
+static inline void
 gfx_stat_to_iattx(struct gfx_iattx *gf_stat, struct iatt *iatt)
 {
     if (!iatt || !gf_stat)
@@ -721,6 +749,12 @@ dict_to_xdr(dict_t *this, gfx_dict *dict)
                 gfx_stat_from_iattx(&xpair->value.gfx_value_u.iatt,
                                     (struct iatt *)dpair->value->data);
                 break;
+            case GF_DATA_TYPE_MDATA:
+                index++;
+                gfx_mdata_iatt_from_mdata_iatt(
+                    &xpair->value.gfx_value_u.mdata_iatt,
+                    (struct mdata_iatt *)dpair->value->data);
+                break;
             case GF_DATA_TYPE_GFUUID:
                 index++;
                 memcpy(&xpair->value.gfx_value_u.uuid, dpair->value->data,
@@ -787,6 +821,7 @@ xdr_to_dict(gfx_dict *dict, dict_t **to)
     dict_t *this = NULL;
     unsigned char *uuid = NULL;
     struct iatt *iatt = NULL;
+    struct mdata_iatt *mdata_iatt = NULL;
 
     if (!to || !dict)
         goto out;
@@ -854,6 +889,30 @@ xdr_to_dict(gfx_dict *dict, dict_t **to)
                 gfx_stat_to_iattx(&xpair->value.gfx_value_u.iatt, iatt);
                 ret = dict_set_iatt(this, key, iatt, false);
                 break;
+            case GF_DATA_TYPE_MDATA:
+                mdata_iatt = GF_CALLOC(1, sizeof(struct mdata_iatt),
+                                       gf_common_mt_char);
+                if (!mdata_iatt) {
+                    errno = ENOMEM;
+                    gf_msg(THIS->name, GF_LOG_ERROR, ENOMEM, LG_MSG_NO_MEMORY,
+                           "failed to allocate memory. key: %s", key);
+                    ret = -1;
+                    goto out;
+                }
+                gfx_mdata_iatt_to_mdata_iatt(
+                    &xpair->value.gfx_value_u.mdata_iatt, mdata_iatt);
+                ret = dict_set_mdata(this, key, mdata_iatt, false);
+                if (ret != 0) {
+                    GF_FREE(mdata_iatt);
+                    gf_msg(THIS->name, GF_LOG_ERROR, ENOMEM,
+                           LG_MSG_DICT_SET_FAILED,
+                           "failed to set the key (%s)"
+                           " into dict",
+                           key);
+                    ret = -1;
+                    goto out;
+                }
+                break;
             case GF_DATA_TYPE_PTR:
             case GF_DATA_TYPE_STR_OLD:
                 value = GF_MALLOC(xpair->value.gfx_value_u.other.other_len + 1,