libglusterfs/gfapi: set appropriate errno for inode_link failures

We do not seem to be setting errno appropriately in case
of inode_link failures. This errno may be used by any application
(for eg., nfs-ganesha) to determine the error encountered. This
patch addresses the same.

This is backport of below mainline fix -
        http://review.gluster.org/14278

Change-Id: I674f747c73369d0597a9c463e6ea4c85b9091355
BUG: 1335016
Signed-off-by: Soumya Koduri <skoduri@redhat.com>
Reviewed-on: http://review.gluster.org/14278
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Reviewed-by: jiffin tony Thottan <jthottan@redhat.com>
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
Reviewed-on: http://review.gluster.org/14287
Smoke: Gluster Build System <jenkins@build.gluster.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.com>

5 files changed, 35 insertions, 12 deletions

diff --git a/api/src/gfapi-messages.h b/api/src/gfapi-messages.h
index c54d821efc7..d15e914dd06 100644
--- a/api/src/gfapi-messages.h
+++ b/api/src/gfapi-messages.h
@@ -45,7 +45,7 @@
  */
 
 #define GLFS_GFAPI_BASE             GLFS_MSGID_COMP_API
-#define GLFS_NUM_MESSAGES           47
+#define GLFS_NUM_MESSAGES           48
 #define GLFS_MSGID_END              (GLFS_GFAPI_BASE + GLFS_NUM_MESSAGESi + 1)
 /* Messages with message IDs */
 #define glfs_msg_start_x GLFS_GFAPI_BASE, "Invalid: Start of messages"
@@ -98,6 +98,7 @@
 #define API_MSG_NEW_GRAPH                       (GLFS_GFAPI_BASE + 45)
 #define API_MSG_ALLOC_FAILED                    (GLFS_GFAPI_BASE + 46)
 #define API_MSG_CREATE_HANDLE_FAILED            (GLFS_GFAPI_BASE + 47)
+#define API_MSG_INODE_LINK_FAILED               (GLFS_GFAPI_BASE + 48)
 
 /*------------*/
 #define glfs_msg_end_x GLFS_MSGID_END, "Invalid: End of messages"
diff --git a/api/src/glfs-fops.c b/api/src/glfs-fops.c
index f01d6adf0ba..0031061620f 100644
--- a/api/src/glfs-fops.c
+++ b/api/src/glfs-fops.c
@@ -127,7 +127,6 @@ glfs_loc_link (loc_t *loc, struct iatt *iatt)
 		ret = 0;
 	} else {
 		ret = -1;
-		errno = ENOMEM;
 	}
 
 	return ret;
diff --git a/api/src/glfs-handleops.c b/api/src/glfs-handleops.c
index 72aa7de146e..721187f8342 100644
--- a/api/src/glfs-handleops.c
+++ b/api/src/glfs-handleops.c
@@ -1332,11 +1332,9 @@ pub_glfs_h_create_from_handle (struct glfs *fs, unsigned char *handle, int len,
                 }
                 inode_lookup (newinode);
         } else {
-                gf_msg (subvol->name, GF_LOG_WARNING, EINVAL,
-                        API_MSG_INVALID_ENTRY,
-                        "inode linking of %s failed: %s",
-                        uuid_utoa (loc.gfid), strerror (errno));
-                errno = EINVAL;
+                gf_msg (subvol->name, GF_LOG_WARNING, errno,
+                        API_MSG_INODE_LINK_FAILED,
+                        "inode linking of %s failed", uuid_utoa (loc.gfid));
                 goto out;
         }
 
diff --git a/api/src/glfs-resolve.c b/api/src/glfs-resolve.c
index f8933326433..c2c6e64fb9d 100644
--- a/api/src/glfs-resolve.c
+++ b/api/src/glfs-resolve.c
@@ -134,6 +134,11 @@ glfs_refresh_inode_safe (xlator_t *subvol, inode_t *oldinode,
                 if (newinode == loc.inode)
                         inode_ctx_set (newinode, THIS, &ctx_value);
                 inode_lookup (newinode);
+        } else {
+                gf_msg (subvol->name, GF_LOG_WARNING, errno,
+                        API_MSG_INODE_LINK_FAILED,
+                        "inode linking of %s failed",
+                        uuid_utoa ((unsigned char *)&iatt.ia_gfid));
         }
 
 	loc_wipe (&loc);
@@ -346,7 +351,14 @@ glfs_resolve_component (struct glfs *fs, xlator_t *subvol, inode_t *parent,
 		goto out;
 
 	inode = inode_link (loc.inode, loc.parent, component, &ciatt);
-        if (inode == loc.inode)
+
+        if (!inode) {
+                gf_msg (subvol->name, GF_LOG_WARNING, errno,
+                        API_MSG_INODE_LINK_FAILED,
+                        "inode linking of %s failed",
+                        uuid_utoa ((unsigned char *)&ciatt.ia_gfid));
+                goto out;
+        } else if (inode == loc.inode)
                 inode_ctx_set (inode, THIS, &ctx_value);
 found:
 	if (inode)
diff --git a/libglusterfs/src/inode.c b/libglusterfs/src/inode.c
index c45e7d1e85b..b70b4a93957 100644
--- a/libglusterfs/src/inode.c
+++ b/libglusterfs/src/inode.c
@@ -934,27 +934,34 @@ __inode_link (inode_t *inode, inode_t *parent, const char *name,
         inode_table_t *table = NULL;
         inode_t       *link_inode = NULL;
 
-        if (!inode)
+        if (!inode) {
+                errno = EINVAL;
                 return NULL;
+        }
 
         table = inode->table;
-        if (!table)
+        if (!table) {
+                errno = EINVAL;
                 return NULL;
+        }
 
         if (parent) {
                 /* We should prevent inode linking between different
                    inode tables. This can cause errors which is very
                    hard to catch/debug. */
                 if (inode->table != parent->table) {
+                        errno = EINVAL;
                         GF_ASSERT (!"link attempted b/w inodes of diff table");
                 }
 
                 if (parent->ia_type != IA_IFDIR) {
+                        errno = EINVAL;
                         GF_ASSERT (!"link attempted on non-directory parent");
                         return NULL;
                 }
 
                 if (!name || strlen (name) == 0) {
+                        errno = EINVAL;
                         GF_ASSERT (!"link attempted with no basename on "
                                     "parent");
                         return NULL;
@@ -964,11 +971,15 @@ __inode_link (inode_t *inode, inode_t *parent, const char *name,
         link_inode = inode;
 
         if (!__is_inode_hashed (inode)) {
-                if (!iatt)
+                if (!iatt) {
+                        errno = EINVAL;
                         return NULL;
+                }
 
-                if (gf_uuid_is_null (iatt->ia_gfid))
+                if (gf_uuid_is_null (iatt->ia_gfid)) {
+                        errno = EINVAL;
                         return NULL;
+                }
 
                 old_inode = __inode_find (table, iatt->ia_gfid);
 
@@ -1015,9 +1026,11 @@ __inode_link (inode_t *inode, inode_t *parent, const char *name,
                                                   "inode %s with parent %s",
                                                   uuid_utoa (link_inode->gfid),
                                                   uuid_utoa (parent->gfid));
+                                errno = ENOMEM;
                                 return NULL;
                         }
                         if (old_inode && __is_dentry_cyclic (dentry)) {
+                                errno = ELOOP;
                                 __dentry_unset (dentry);
                                 return NULL;
                         }