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#1733885
Signed-off-by: Kotresh HR <khiremat@redhat.com>

5 files changed, 90 insertions, 0 deletions

diff --git a/libglusterfs/src/dict.c b/libglusterfs/src/dict.c
index 4cd1fcf5bc0..a5568fc1ef2 100644
--- a/libglusterfs/src/dict.c
+++ b/libglusterfs/src/dict.c
@@ -124,6 +124,7 @@ int32_t
 is_data_equal(data_t *one, data_t *two)
 {
     struct iatt *iatt1, *iatt2;
+    struct mdata_iatt *mdata_iatt1, *mdata_iatt2;
 
     if (!one || !two || !one->data || !two->data) {
         gf_msg_callingfn("dict", GF_LOG_ERROR, EINVAL, LG_MSG_INVALID_ARG,
@@ -188,6 +189,24 @@ is_data_equal(data_t *one, data_t *two)
         */
         return 1;
     }
+    if (one->data_type == GF_DATA_TYPE_MDATA) {
+        if ((one->len < sizeof(struct mdata_iatt)) ||
+            (two->len < sizeof(struct mdata_iatt))) {
+            return 0;
+        }
+        mdata_iatt1 = (struct mdata_iatt *)one->data;
+        mdata_iatt2 = (struct mdata_iatt *)two->data;
+
+        if (mdata_iatt1->ia_atime != mdata_iatt2->ia_atime ||
+            mdata_iatt1->ia_mtime != mdata_iatt2->ia_mtime ||
+            mdata_iatt1->ia_ctime != mdata_iatt2->ia_ctime ||
+            mdata_iatt1->ia_atime_nsec != mdata_iatt2->ia_atime_nsec ||
+            mdata_iatt1->ia_mtime_nsec != mdata_iatt2->ia_mtime_nsec ||
+            mdata_iatt1->ia_ctime_nsec != mdata_iatt2->ia_ctime_nsec) {
+            return 0;
+        }
+        return 1;
+    }
 
     if (one->len != two->len)
         return 0;
@@ -1078,6 +1097,7 @@ static char *data_type_name[GF_DATA_TYPE_MAX] = {
     [GF_DATA_TYPE_PTR] = "pointer",
     [GF_DATA_TYPE_GFUUID] = "gf-uuid",
     [GF_DATA_TYPE_IATT] = "iatt",
+    [GF_DATA_TYPE_MDATA] = "mdata",
 };
 
 int64_t
@@ -2666,6 +2686,45 @@ err:
 }
 
 int
+dict_set_mdata(dict_t *this, char *key, struct mdata_iatt *mdata,
+               bool is_static)
+{
+    return dict_set_bin_common(this, key, mdata, sizeof(struct mdata_iatt),
+                               is_static, GF_DATA_TYPE_MDATA);
+}
+
+int
+dict_get_mdata(dict_t *this, char *key, struct mdata_iatt *mdata)
+{
+    data_t *data = NULL;
+    int ret = -EINVAL;
+
+    if (!this || !key || !mdata) {
+        goto err;
+    }
+    ret = dict_get_with_ref(this, key, &data);
+    if (ret < 0) {
+        goto err;
+    }
+
+    VALIDATE_DATA_AND_LOG(data, GF_DATA_TYPE_MDATA, key, -EINVAL);
+    if (data->len < sizeof(struct mdata_iatt)) {
+        gf_msg("glusterfs", GF_LOG_ERROR, ENOBUFS, LG_MSG_UNDERSIZED_BUF,
+               "data value for '%s' is smaller than expected", key);
+        ret = -ENOBUFS;
+        goto err;
+    }
+
+    memcpy(mdata, data->data, min(data->len, sizeof(struct mdata_iatt)));
+
+err:
+    if (data)
+        data_unref(data);
+
+    return ret;
+}
+
+int
 dict_set_iatt(dict_t *this, char *key, struct iatt *iatt, bool is_static)
 {
     return dict_set_bin_common(this, key, iatt, sizeof(struct iatt), is_static,
diff --git a/libglusterfs/src/glusterfs/dict.h b/libglusterfs/src/glusterfs/dict.h
index 52b833fd559..c8ea9c1bc0b 100644
--- a/libglusterfs/src/glusterfs/dict.h
+++ b/libglusterfs/src/glusterfs/dict.h
@@ -389,6 +389,11 @@ GF_MUST_CHECK int
 dict_set_iatt(dict_t *this, char *key, struct iatt *iatt, bool is_static);
 GF_MUST_CHECK int
 dict_get_iatt(dict_t *this, char *key, struct iatt *iatt);
+GF_MUST_CHECK int
+dict_set_mdata(dict_t *this, char *key, struct mdata_iatt *mdata,
+               bool is_static);
+GF_MUST_CHECK int
+dict_get_mdata(dict_t *this, char *key, struct mdata_iatt *mdata);
 
 void
 dict_dump_to_statedump(dict_t *dict, char *dict_name, char *domain);
diff --git a/libglusterfs/src/glusterfs/glusterfs.h b/libglusterfs/src/glusterfs/glusterfs.h
index 3056a61d9af..cded97835a6 100644
--- a/libglusterfs/src/glusterfs/glusterfs.h
+++ b/libglusterfs/src/glusterfs/glusterfs.h
@@ -229,6 +229,9 @@ enum gf_internal_fop_indicator {
 #define VIRTUAL_QUOTA_XATTR_CLEANUP_KEY "glusterfs.quota-xattr-cleanup"
 #define QUOTA_READ_ONLY_KEY "trusted.glusterfs.quota.read-only"
 
+/* ctime related */
+#define CTIME_MDATA_XDATA_KEY "set-ctime-mdata"
+
 /* afr related */
 #define AFR_XATTR_PREFIX "trusted.afr"
 
diff --git a/libglusterfs/src/glusterfs/iatt.h b/libglusterfs/src/glusterfs/iatt.h
index bee7a0afa77..f03d68b02f0 100644
--- a/libglusterfs/src/glusterfs/iatt.h
+++ b/libglusterfs/src/glusterfs/iatt.h
@@ -92,6 +92,15 @@ struct old_iatt {
     uint32_t ia_ctime_nsec;
 };
 
+struct mdata_iatt {
+    int64_t ia_atime; /* last access time */
+    int64_t ia_mtime; /* last modification time */
+    int64_t ia_ctime; /* last status change time */
+    uint32_t ia_atime_nsec;
+    uint32_t ia_mtime_nsec;
+    uint32_t ia_ctime_nsec;
+};
+
 /* 64-bit mask for valid members in struct iatt. */
 #define IATT_TYPE 0x0000000000000001U
 #define IATT_MODE 0x0000000000000002U
@@ -313,6 +322,17 @@ st_mode_from_ia(ia_prot_t prot, ia_type_t type)
     return st_mode;
 }
 
+static inline void
+iatt_to_mdata(struct mdata_iatt *mdata, struct iatt *iatt)
+{
+    mdata->ia_atime = iatt->ia_atime;
+    mdata->ia_atime_nsec = iatt->ia_atime_nsec;
+    mdata->ia_mtime = iatt->ia_mtime;
+    mdata->ia_mtime_nsec = iatt->ia_mtime_nsec;
+    mdata->ia_ctime = iatt->ia_ctime;
+    mdata->ia_ctime_nsec = iatt->ia_ctime_nsec;
+}
+
 static inline int
 iatt_from_stat(struct iatt *iatt, struct stat *stat)
 {
diff --git a/libglusterfs/src/libglusterfs.sym b/libglusterfs/src/libglusterfs.sym
index 3a548305dd8..6a10af86a23 100644
--- a/libglusterfs/src/libglusterfs.sym
+++ b/libglusterfs/src/libglusterfs.sym
@@ -380,6 +380,7 @@ dict_get_bin
 dict_get_double
 dict_get_gfuuid
 dict_get_iatt
+dict_get_mdata
 dict_get_int16
 dict_get_int32
 dict_get_int32n
@@ -416,6 +417,7 @@ dict_set_dynstrn
 dict_set_dynstr_with_alloc
 dict_set_gfuuid
 dict_set_iatt
+dict_set_mdata
 dict_set_int16
 dict_set_int32
 dict_set_int32n
@@ -508,6 +510,7 @@ fop_lease_stub
 fop_link_stub
 fop_lk_stub
 fop_log_level
+fop_lookup_cbk_stub
 fop_lookup_stub
 fop_mkdir_stub
 fop_mknod_stub