readdir-ahead: do not zero-out iatt in fop cbk

...when ctime is zero. ia_type and ia_gfid always need to be non-zero
for things to work correctly.

Problem:
Commit c9bde3021202f1d5c5a2d19ac05a510fc1f788ac zeroed out the iatt
buffer in the cbks of modification fops before unwinding if the ctime in
the buffer was zero. This was causing the fops to fail: noticeable when
AFR's 'consistent-metadata' option was enabled. (AFR zeros out the ctime
when the option is set. See commit
4c4624c9bad2edf27128cb122c64f15d7d63bbc8).

Fixes:
-Do not zero out the ia_type and ia_gfid of the iatt buff under any
circumstance.
-Also, fixed _rda_inode_ctx_update_iatts() to always update these values from
the incoming buf when ctime is zero. Otherwise we end up with zero
ia_type and ia_gfid the first time the function is called *and* the
incoming buf has ctime set to zero.

fixes: bz#1670253
Reported-By:Michael Hanselmann <public@hansmi.ch>
Change-Id: Ib72228892d42c3513c19fc6dfb543f2aa3489eca
Signed-off-by: Ravishankar N <ravishankar@redhat.com>

2 files changed, 27 insertions, 20 deletions

diff --git a/tests/bugs/readdir-ahead/bug-1670253-consistent-metadata.t b/tests/bugs/readdir-ahead/bug-1670253-consistent-metadata.t
new file mode 100644
index 00000000000..6adfc17c92c
--- /dev/null
+++ b/tests/bugs/readdir-ahead/bug-1670253-consistent-metadata.t
@@ -0,0 +1,23 @@
+#!/bin/bash
+
+. $(dirname $0)/../../include.rc
+. $(dirname $0)/../../volume.rc
+
+cleanup;
+
+TEST glusterd
+
+TEST $CLI volume create $V0 replica 3 $H0:$B0/${V0}{0,1,2}
+TEST $CLI volume set $V0 readdir-ahead on #on by default as of writing this .t.
+TEST $CLI volume set $V0 consistent-metadata on
+TEST $CLI volume start $V0
+TEST glusterfs --volfile-server=$H0 --volfile-id=$V0 $M0
+TEST touch $M0/FILE
+echo "abc" >> $M0/FILE
+EXPECT "^0$" echo $?
+EXPECT "abc" cat $M0/FILE
+echo "truncate" >$M0/FILE
+EXPECT "^0$" echo $?
+EXPECT "truncate" cat $M0/FILE
+EXPECT_WITHIN $UMOUNT_TIMEOUT "Y" force_umount $M0
+cleanup;
diff --git a/xlators/performance/readdir-ahead/src/readdir-ahead.c b/xlators/performance/readdir-ahead/src/readdir-ahead.c
index e7fe0f7c7f5..b3363b8b884 100644
--- a/xlators/performance/readdir-ahead/src/readdir-ahead.c
+++ b/xlators/performance/readdir-ahead/src/readdir-ahead.c
@@ -129,7 +129,10 @@ __rda_inode_ctx_update_iatts(inode_t *inode, xlator_t *this,
          * An example of this case can be response of write request
          * that is cached in write-behind.
          */
-        tmp_stat = ctx_p->statbuf;
+        if (stbuf_in)
+            tmp_stat = *stbuf_in;
+        else
+            tmp_stat = ctx_p->statbuf;
         memset(&ctx_p->statbuf, 0, sizeof(ctx_p->statbuf));
         gf_uuid_copy(ctx_p->statbuf.ia_gfid, tmp_stat.ia_gfid);
         ctx_p->statbuf.ia_type = tmp_stat.ia_type;
@@ -768,8 +771,6 @@ rda_writev_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
     rda_inode_ctx_update_iatts(local->inode, this, postbuf, &postbuf_out,
                                local->generation);
 
-    if (postbuf_out.ia_ctime == 0)
-        memset(&postbuf_out, 0, sizeof(postbuf_out));
 unwind:
     RDA_STACK_UNWIND(writev, frame, op_ret, op_errno, prebuf, &postbuf_out,
                      xdata);
@@ -804,9 +805,6 @@ rda_fallocate_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
     rda_inode_ctx_update_iatts(local->inode, this, postbuf, &postbuf_out,
                                local->generation);
 
-    if (postbuf_out.ia_ctime == 0)
-        memset(&postbuf_out, 0, sizeof(postbuf_out));
-
 unwind:
     RDA_STACK_UNWIND(fallocate, frame, op_ret, op_errno, prebuf, &postbuf_out,
                      xdata);
@@ -840,9 +838,6 @@ rda_zerofill_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
     rda_inode_ctx_update_iatts(local->inode, this, postbuf, &postbuf_out,
                                local->generation);
 
-    if (postbuf_out.ia_ctime == 0)
-        memset(&postbuf_out, 0, sizeof(postbuf_out));
-
 unwind:
     RDA_STACK_UNWIND(zerofill, frame, op_ret, op_errno, prebuf, &postbuf_out,
                      xdata);
@@ -876,8 +871,6 @@ rda_discard_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
     rda_inode_ctx_update_iatts(local->inode, this, postbuf, &postbuf_out,
                                local->generation);
 
-    if (postbuf_out.ia_ctime == 0)
-        memset(&postbuf_out, 0, sizeof(postbuf_out));
 unwind:
     RDA_STACK_UNWIND(discard, frame, op_ret, op_errno, prebuf, &postbuf_out,
                      xdata);
@@ -911,9 +904,6 @@ rda_ftruncate_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
     rda_inode_ctx_update_iatts(local->inode, this, postbuf, &postbuf_out,
                                local->generation);
 
-    if (postbuf_out.ia_ctime == 0)
-        memset(&postbuf_out, 0, sizeof(postbuf_out));
-
 unwind:
     RDA_STACK_UNWIND(ftruncate, frame, op_ret, op_errno, prebuf, &postbuf_out,
                      xdata);
@@ -946,8 +936,6 @@ rda_truncate_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
     rda_mark_inode_dirty(this, local->inode);
     rda_inode_ctx_update_iatts(local->inode, this, postbuf, &postbuf_out,
                                local->generation);
-    if (postbuf_out.ia_ctime == 0)
-        memset(&postbuf_out, 0, sizeof(postbuf_out));
 
 unwind:
     RDA_STACK_UNWIND(ftruncate, frame, op_ret, op_errno, prebuf, &postbuf_out,
@@ -1035,8 +1023,6 @@ rda_setattr_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
     rda_mark_inode_dirty(this, local->inode);
     rda_inode_ctx_update_iatts(local->inode, this, statpost, &postbuf_out,
                                local->generation);
-    if (postbuf_out.ia_ctime == 0)
-        memset(&postbuf_out, 0, sizeof(postbuf_out));
 
 unwind:
     RDA_STACK_UNWIND(setattr, frame, op_ret, op_errno, statpre, &postbuf_out,
@@ -1070,8 +1056,6 @@ rda_fsetattr_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
     rda_mark_inode_dirty(this, local->inode);
     rda_inode_ctx_update_iatts(local->inode, this, statpost, &postbuf_out,
                                local->generation);
-    if (postbuf_out.ia_ctime == 0)
-        memset(&postbuf_out, 0, sizeof(postbuf_out));
 
 unwind:
     RDA_STACK_UNWIND(fsetattr, frame, op_ret, op_errno, statpre, &postbuf_out,