afr: refresh inode using fstat

Backport of http://review.gluster.org/12894

For fd based operations (fgetxattr, readv etc.) if an inode refresh is
required, do so using fstat instead of lookup. This is because the file
might have been deleted by another client before refresh but posix
mandates that FOPS using already open fds must still succeed.

Change-Id: Id5f71c3af4892b648eb747f363dffe6208e7ac09
BUG: 1290363
Signed-off-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-on: http://review.gluster.org/13040
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>

1 files changed, 53 insertions, 12 deletions

diff --git a/xlators/features/index/src/index.c b/xlators/features/index/src/index.c
index 482292a00f9..3a717def2f6 100644
--- a/xlators/features/index/src/index.c
+++ b/xlators/features/index/src/index.c
@@ -1359,16 +1359,14 @@ out:
         return count;
 }
 
-int32_t
-index_lookup_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
-                  int32_t op_ret, int32_t op_errno, inode_t *inode,
-                  struct iatt *buf, dict_t *xdata, struct iatt *postparent)
+dict_t*
+index_fill_link_count (xlator_t *this, dict_t *xdata)
 {
-        int              ret  = -1;
-        char            *dir  = NULL;
-        index_priv_t    *priv = this->private;
-        int64_t          count    = -1;
+        int             ret       = -1;
+        index_priv_t    *priv     = NULL;
+        int64_t         count     = -1;
 
+        priv = this->private;
         xdata = (xdata) ? dict_ref (xdata) : dict_new ();
         if (!xdata)
                 goto out;
@@ -1382,14 +1380,26 @@ index_lookup_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
         if (count == 0) {
                 ret = dict_set_int8 (xdata, "link-count", 0);
                 if (ret < 0)
-                        goto out;
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Unable to set link-count");
         } else {
                 ret = dict_set_int8 (xdata, "link-count", 1);
                 if (ret < 0)
-                       goto out;
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Unable to set link-count");
         }
 
 out:
+        return xdata;
+}
+
+int32_t
+index_lookup_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
+                  int32_t op_ret, int32_t op_errno, inode_t *inode,
+                  struct iatt *buf, dict_t *xdata, struct iatt *postparent)
+{
+
+        xdata = index_fill_link_count (this, xdata);
         STACK_UNWIND_STRICT (lookup, frame, op_ret, op_errno, inode, buf,
                              xdata, postparent);
         if (xdata)
@@ -1424,7 +1434,7 @@ index_lookup (call_frame_t *frame, xlator_t *this,
         return 0;
 normal:
         ret = dict_get_str (xattr_req, "link-count", &flag);
-        if (!(ret || strcmp (flag, GF_XATTROP_INDEX_COUNT))) {
+        if ((ret == 0) && (strcmp (flag, GF_XATTROP_INDEX_COUNT) == 0)) {
                 STACK_WIND (frame, index_lookup_cbk, FIRST_CHILD(this),
                             FIRST_CHILD(this)->fops->lookup, loc, xattr_req);
         } else {
@@ -1436,6 +1446,36 @@ normal:
 }
 
 int32_t
+index_fstat_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
+                 int32_t op_ret, int32_t op_errno, struct iatt *buf,
+                 dict_t *xdata)
+{
+        xdata = index_fill_link_count (this, xdata);
+        STACK_UNWIND_STRICT (fstat, frame, op_ret, op_errno, buf, xdata);
+        if (xdata)
+                dict_unref (xdata);
+        return 0;
+}
+
+int32_t
+index_fstat (call_frame_t *frame, xlator_t *this, fd_t *fd, dict_t *xdata)
+{
+        int  ret   = -1;
+        char *flag = NULL;
+
+        ret = dict_get_str (xdata, "link-count", &flag);
+        if ((ret == 0) && (strcmp (flag, GF_XATTROP_INDEX_COUNT) == 0)) {
+                STACK_WIND (frame, index_fstat_cbk, FIRST_CHILD(this),
+                            FIRST_CHILD(this)->fops->fstat, fd, xdata);
+        } else {
+                STACK_WIND (frame, default_fstat_cbk, FIRST_CHILD(this),
+                            FIRST_CHILD(this)->fops->fstat, fd, xdata);
+        }
+
+        return 0;
+}
+
+int32_t
 index_opendir (call_frame_t *frame, xlator_t *this,
                loc_t *loc, fd_t *fd, dict_t *xdata)
 {
@@ -1815,7 +1855,8 @@ struct xlator_fops fops = {
         .lookup      = index_lookup,
         .opendir     = index_opendir,
         .readdir     = index_readdir,
-        .unlink      = index_unlink
+        .unlink      = index_unlink,
+        .fstat       = index_fstat,
 };
 
 struct xlator_dumpops dumpops;