storage/posix: calculate the correct size of each dirent in readdir/readdirp.

- In addition to posix, protocol/server also adds a check to make sure that
   iobuf allocated to hold readdir/readdirp response can hold all the dentries,
   rpc and proc (readdir/readdirp) header.

Signed-off-by: Raghavendra G <raghavendra@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 1430 (encoding of readdirp response fails occasionally)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=1430

3 files changed, 38 insertions, 13 deletions

diff --git a/xlators/protocol/server/src/server3_1-fops.c b/xlators/protocol/server/src/server3_1-fops.c
index 69f37d6b370..c73f3df15be 100644
--- a/xlators/protocol/server/src/server3_1-fops.c
+++ b/xlators/protocol/server/src/server3_1-fops.c
@@ -3868,9 +3868,10 @@ out:
 int
 server_readdirp (rpcsvc_request_t *req)
 {
-        server_state_t      *state = NULL;
-        call_frame_t        *frame = NULL;
-        gfs3_readdirp_req    args  = {0,};
+        server_state_t      *state        = NULL;
+        call_frame_t        *frame        = NULL;
+        gfs3_readdirp_req    args         = {0,};
+        size_t               headers_size = 0;
 
         if (!req)
                 return 0;
@@ -3896,9 +3897,19 @@ server_readdirp (rpcsvc_request_t *req)
                 goto out;
         }
 
+        /* FIXME: this should go away when variable sized iobufs are introduced
+         * and transport layer can send msgs bigger than current page-size.
+         */
+        headers_size = sizeof (struct rpc_msg) + sizeof (gfs3_readdir_rsp);
+        if ((frame->this->ctx->page_size < args.size)
+            || ((frame->this->ctx->page_size - args.size) < headers_size)) {
+                state->size = frame->this->ctx->page_size - headers_size;
+        } else {
+                state->size   = args.size;
+        }
+
         state->resolve.type = RESOLVE_MUST;
         state->resolve.fd_no = args.fd;
-        state->size   = args.size;
         state->offset = args.offset;
 
         resolve_and_resume (frame, server_readdirp_resume);
@@ -3909,9 +3920,10 @@ out:
 int
 server_readdir (rpcsvc_request_t *req)
 {
-        server_state_t      *state = NULL;
-        call_frame_t        *frame = NULL;
-        gfs3_readdir_req     args  = {0,};
+        server_state_t      *state        = NULL;
+        call_frame_t        *frame        = NULL;
+        gfs3_readdir_req     args         = {0,};
+        size_t               headers_size = 0;
 
         if (!req)
                 return 0;
@@ -3937,9 +3949,19 @@ server_readdir (rpcsvc_request_t *req)
                 goto out;
         }
 
+        /* FIXME: this should go away when variable sized iobufs are introduced
+         * and transport layer can send msgs bigger than current page-size.
+         */
+        headers_size = sizeof (struct rpc_msg) + sizeof (gfs3_readdir_rsp);
+        if ((frame->this->ctx->page_size < args.size)
+            || ((frame->this->ctx->page_size - args.size) < headers_size)) {
+                state->size = frame->this->ctx->page_size - headers_size;
+        } else {
+                state->size   = args.size;
+        }
+
         state->resolve.type = RESOLVE_MUST;
         state->resolve.fd_no = args.fd;
-        state->size   = args.size;
         state->offset = args.offset;
 
         resolve_and_resume (frame, server_readdir_resume);
diff --git a/xlators/storage/posix/src/Makefile.am b/xlators/storage/posix/src/Makefile.am
index 0fdcfdcecb4..b8d1668aee9 100644
--- a/xlators/storage/posix/src/Makefile.am
+++ b/xlators/storage/posix/src/Makefile.am
@@ -9,10 +9,10 @@ posix_la_LIBADD = $(top_builddir)/libglusterfs/src/libglusterfs.la
 
 noinst_HEADERS = posix.h posix-mem-types.h
 
-AM_CFLAGS = -fPIC -fno-strict-aliasing -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -D$(GF_HOST_OS) -Wall \
-	-I$(top_srcdir)/libglusterfs/src -shared -nostartfiles \
-	-I$(top_srcdir)/contrib/md5 \
-	$(GF_CFLAGS)
+AM_CFLAGS = -fPIC -fno-strict-aliasing -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE \
+            -D$(GF_HOST_OS) -Wall -I$(top_srcdir)/libglusterfs/src -shared \
+            -nostartfiles -I$(top_srcdir)/contrib/md5 -I$(top_srcdir)/rpc/xdr/src \
+            -I$(top_srcdir)/rpc/rpc-lib/src $(GF_CFLAGS)
 
 CLEANFILES =
 
diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c
index 1fd369b8ffe..c75429b0eb5 100644
--- a/xlators/storage/posix/src/posix.c
+++ b/xlators/storage/posix/src/posix.c
@@ -52,6 +52,7 @@
 #include "statedump.h"
 #include "locking.h"
 #include "timer.h"
+#include "glusterfs3-xdr.h"
 
 #undef HAVE_SET_FSID
 #ifdef HAVE_SET_FSID
@@ -4016,7 +4017,9 @@ posix_do_readdir (call_frame_t *frame, xlator_t *this,
                     && (!strcmp(entry->d_name, GF_REPLICATE_TRASH_DIR)))
                         continue;
 
-                this_size = dirent_size (entry);
+                this_size = max (sizeof (gf_dirent_t),
+                                 sizeof (gfs3_dirplist))
+                        + strlen (entry->d_name) + 1;
 
                 if (this_size + filled > size) {
                         seekdir (dir, in_case);