gfapi: Fix IO error caused when there is consecutive graph switches

Backport of http://review.gluster.org/#/c/14656/

Issue:
Consider a simple situation, where glfs_init() is done, i.e. initial
graph is up. Now perform 2 volume sets that results in 2 client side
graph changes. After this perform some IO, the IO fails with ENOTCON.
The only way to recover this client is i guess another graph switch
or restart.

What actually is happening from code perspective:
Initial graph lets say A, followed by 2 consecutive graph switches
to B and C without any IO those two switches.

- graph_setup (A) as a result of GF_EVENT_CHILD_UP, and
fs->next_subvol = A

- glfs_init() results in fs->active_subvol = A, fs->next_subvol = NULL

- graph_setup (B) as a result of GF_EVENT_CHILD_UP, and
fs->next_subvol = B

- graph_setup (C) as a result of GF_EVENT_CHILD_UP, and
fs->next_subvol = C. It also sees that the previous graph B was never
set as fs->active_subvol, i.e. no IO or anything happened on B, so
can safely send GF_EVENT_PARENT_DOWN (by calling glfs_subvol_done(B)).
This parent down on B, results in child_down(B), which is fine.
But child_down also triggers graph_setup(B).

- graph_setup(B) as a result of GF_EVENT_CHILD_DOWN, and
fs->next_subvol = B, and GF_EVENT_PARENT_DOWN on C as explained
above. This again leads to GF_EVENT_CHILD_DOWN on C.

- graph_setup(C) as a result of GF_EVENT_CHILD_DOWN, and
fs->next_subvol = C, and GF_EVENT_PARENT_DOWN on B as explained
above.

Thus both the graphs B and C are disconnected, and hence the ENOTCON

Solution:
Remove the call to graph_setup() when the event is GF_EVENT_CHILD_DOWN.
It don't see any reason why graph_setup should be called when there is
child_down. Not sure what the original reason was, to have graph_setup
in child_down. git hostory shows the first patch itself had this call.

Change-Id: I9de86555f66cc94a05649ac863b40ed3426ffd4b
BUG: 1347489
Signed-off-by: Poornima G <pgurusid@redhat.com>
Reviewed-on: http://review.gluster.org/14656
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>
(cherry picked from commit b8ac20e888fbacad9d90cd8f1c6ff8579a5cefe9)
Reviewed-on: http://review.gluster.org/14747

2 files changed, 0 insertions, 335 deletions

diff --git a/tests/bugs/gfapi/bug-1093594.c b/tests/bugs/gfapi/bug-1093594.c
deleted file mode 100644
index 8f5aa9be66c..00000000000
--- a/tests/bugs/gfapi/bug-1093594.c
+++ /dev/null
@@ -1,315 +0,0 @@
-#include "../../api/src/glfs.h"
-#include "../../api/src/glfs-handles.h"
-#include <errno.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#define WRITE_SIZE (128*1024)
-#define READ_WRITE_LOOP 100
-#define FOP_LOOP_COUNT 20
-#define TEST_CASE_LOOP 20
-
-int gfapi = 1;
-static int extension = 1;
-
-static int
-large_number_of_fops (glfs_t *fs) {
-        int       ret       = 0;
-        int       i         = 0;
-        glfs_fd_t *fd       = NULL;
-        glfs_fd_t *fd1      = NULL;
-        char      *dir1     = NULL, *dir2 = NULL, *filename1 = NULL, *filename2 = NULL;
-        char      *buf      = NULL;
-        struct stat sb      = {0, };
-
-        for (i = 0 ; i < FOP_LOOP_COUNT ; i++) {
-                ret = asprintf (&dir1, "dir%d", extension);
-                if (ret < 0) {
-                        fprintf (stderr, "cannot construct filename (%s)",
-                                 strerror (errno));
-                        return ret;
-                }
-
-                extension++;
-
-                ret = glfs_mkdir (fs, dir1, 0755);
-                if (ret < 0) {
-                        fprintf (stderr, "mkdir(%s): %s\n", dir1, strerror (errno));
-                        return -1;
-                }
-
-                fd = glfs_opendir (fs, dir1);
-                if (!fd) {
-                        fprintf (stderr, "/: %s\n", strerror (errno));
-                        return -1;
-                }
-
-                ret = glfs_fsetxattr (fd, "user.dirfattr", "fsetxattr", 8, 0);
-                if (ret < 0) {
-                        fprintf (stderr, "fsetxattr(%s): %d (%s)\n", dir1, ret,
-                                strerror (errno));
-                        return -1;
-                }
-
-                ret = glfs_closedir (fd);
-                if (ret < 0) {
-                        fprintf (stderr, "glfs_closedir failed with ret: %d (%s)\n",
-                                ret, strerror (errno));
-                        return -1;
-                }
-
-                ret = glfs_rmdir (fs, dir1);
-                if (ret < 0) {
-                        fprintf (stderr, "glfs_unlink failed with ret: %d (%s)\n",
-                                ret, strerror (errno));
-                        return -1;
-                }
-
-                ret = asprintf (&filename1, "file%d", extension);
-                if (ret < 0) {
-                        fprintf (stderr, "cannot construct filename (%s)",
-                                strerror (errno));
-                        return ret;
-                }
-
-                ret = asprintf (&filename2, "file-%d", extension);
-                if (ret < 0) {
-                        fprintf (stderr, "cannot construct filename (%s)",
-                                strerror (errno));
-                        return ret;
-                }
-
-                extension++;
-
-                fd = glfs_creat (fs, filename1, O_RDWR, 0644);
-                if (!fd) {
-                        fprintf (stderr, "%s: (%p) %s\n", filename1, fd,
-                                strerror (errno));
-                        return -1;
-                }
-
-                ret = glfs_rename (fs, filename1, filename2);
-                if (ret < 0) {
-                        fprintf (stderr, "glfs_rename failed with ret: %d (%s)\n",
-                                ret, strerror (errno));
-                        return -1;
-                }
-
-                ret = glfs_lstat (fs, filename2, &sb);
-                if (ret < 0) {
-                        fprintf (stderr, "glfs_lstat failed with ret: %d (%s)\n",
-                                ret, strerror (errno));
-                        return -1;
-                }
-
-                ret = glfs_close (fd);
-                if (ret < 0) {
-                        fprintf (stderr, "glfs_close failed with ret: %d (%s)\n",
-                                ret, strerror (errno));
-                        return -1;
-                }
-
-                ret = glfs_unlink (fs, filename2);
-                if (ret < 0) {
-                        fprintf (stderr, "glfs_unlink failed with ret: %d (%s)\n",
-                                ret, strerror (errno));
-                        return -1;
-                }
-        }
-}
-
-static int
-large_read_write (glfs_t *fs) {
-
-        int       ret       = 0;
-        int       j         = 0;
-        glfs_fd_t *fd       = NULL;
-        glfs_fd_t *fd1      = NULL;
-        char      *filename = NULL;
-        char      *buf      = NULL;
-
-        ret = asprintf (&filename, "filerw%d", extension);
-        if (ret < 0) {
-                fprintf (stderr, "cannot construct filename (%s)",
-                         strerror (errno));
-                return ret;
-        }
-
-        extension++;
-
-        fd = glfs_creat (fs, filename, O_RDWR, 0644);
-        if (!fd) {
-                fprintf (stderr, "%s: (%p) %s\n", filename, fd,
-                        strerror (errno));
-                return -1;
-        }
-
-        buf = (char *) malloc (WRITE_SIZE);
-        memset (buf, '-', WRITE_SIZE);
-
-        for (j = 0; j < READ_WRITE_LOOP; j++) {
-                ret = glfs_write (fd, buf, WRITE_SIZE, 0);
-                if (ret < 0) {
-                        fprintf (stderr, "Write(%s): %d (%s)\n", filename, ret,
-                                strerror (errno));
-                        return ret;
-                }
-        }
-
-        fd1 = glfs_open (fs, filename, O_RDWR);
-        if (fd1 < 0) {
-                fprintf (stderr, "Open(%s): %d (%s)\n", filename, ret,
-                        strerror (errno));
-                return -1;
-        }
-
-        glfs_lseek (fd1, 0, SEEK_SET);
-        for (j = 0; j < READ_WRITE_LOOP; j++) {
-                ret = glfs_read (fd1, buf, WRITE_SIZE, 0);
-                if (ret < 0) {
-                        fprintf (stderr, "Read(%s): %d (%s)\n", filename, ret,
-                                strerror (errno));
-                        return ret;
-                }
-        }
-
-        for (j = 0; j < READ_WRITE_LOOP; j++) {
-                ret = glfs_write (fd1, buf, WRITE_SIZE, 0);
-                if (ret < 0) {
-                        fprintf (stderr, "Write(%s): %d (%s)\n", filename, ret,
-                                strerror (errno));
-                        return ret;
-                }
-        }
-
-        glfs_close (fd);
-        glfs_close (fd1);
-        ret = glfs_unlink (fs, filename);
-        if (ret < 0) {
-                fprintf (stderr, "glfs_unlink failed with ret: %d (%s)\n",
-                        ret, strerror (errno));
-                return -1;
-        }
-
-        free (buf);
-        free (filename);
-}
-
-static int
-volfile_change (const char *volname) {
-        int   ret = 0;
-        char *cmd = NULL, *cmd1 = NULL;
-
-        ret = asprintf (&cmd, "gluster volume set %s stat-prefetch off",
-                        volname);
-        if (ret < 0) {
-                fprintf (stderr, "cannot construct cli command string (%s)",
-                         strerror (errno));
-                return ret;
-        }
-
-        ret = asprintf (&cmd1, "gluster volume set %s stat-prefetch on",
-                        volname);
-        if (ret < 0) {
-                fprintf (stderr, "cannot construct cli command string (%s)",
-                         strerror (errno));
-                return ret;
-        }
-
-        ret = system (cmd);
-        if (ret < 0) {
-                fprintf (stderr, "stat-prefetch off on (%s) failed", volname);
-                return ret;
-        }
-
-        ret = system (cmd1);
-        if (ret < 0) {
-                fprintf (stderr, "stat-prefetch on on (%s) failed", volname);
-                return ret;
-        }
-
-        free (cmd);
-        free (cmd1);
-        return ret;
-}
-
-int
-main (int argc, char *argv[])
-{
-        glfs_t    *fs       = NULL;
-        int       ret       = 0;
-        int       i         = 0;
-        glfs_fd_t *fd       = NULL;
-        glfs_fd_t *fd1      = NULL;
-        char      *topdir   = "topdir", *filename = "file1";
-        char      *buf      = NULL;
-        char      *logfile  = NULL;
-
-        if (argc != 3) {
-                fprintf (stderr,
-                        "Expect following args %s <Vol> <log file>\n"
-                        , argv[0]);
-                return -1;
-        }
-
-        logfile = argv[2];
-
-        for (i = 0; i < TEST_CASE_LOOP; i++) {
-                fs = glfs_new (argv[1]);
-                if (!fs) {
-                        fprintf (stderr, "glfs_new: returned NULL (%s)\n",
-                                strerror (errno));
-                        return -1;
-                }
-
-                ret = glfs_set_volfile_server (fs, "tcp", "localhost", 24007);
-                if (ret < 0) {
-                        fprintf (stderr, "glfs_set_volfile_server failed ret:%d (%s)\n",
-                        ret, strerror (errno));
-                        return -1;
-                }
-
-                ret = glfs_set_logging (fs, logfile, 7);
-                if (ret < 0) {
-                        fprintf (stderr, "glfs_set_logging failed with ret: %d (%s)\n",
-                                ret, strerror (errno));
-                        return -1;
-                }
-
-                ret = glfs_init (fs);
-                if (ret < 0) {
-                        fprintf (stderr, "glfs_init failed with ret: %d (%s)\n",
-                                ret, strerror (errno));
-                        return -1;
-                }
-
-                ret = large_number_of_fops (fs);
-                if (ret < 0)
-                        return -1;
-
-                ret = large_read_write (fs);
-                if (ret < 0)
-                        return -1;
-
-                ret = volfile_change (argv[1]);
-                if (ret < 0)
-                        return -1;
-
-                ret = large_number_of_fops (fs);
-                if (ret < 0)
-                        return -1;
-
-                ret = large_read_write (fs);
-                if (ret < 0)
-                        return -1;
-
-                ret = glfs_fini (fs);
-                if (ret < 0) {
-                        fprintf (stderr, "glfs_fini failed with ret: %d (%s)\n",
-                                ret, strerror (errno));
-                        return -1;
-                }
-        }
-        return 0;
-}
diff --git a/tests/bugs/gfapi/bug-1093594.sh b/tests/bugs/gfapi/bug-1093594.sh
deleted file mode 100755
index 444319b8e63..00000000000
--- a/tests/bugs/gfapi/bug-1093594.sh
+++ /dev/null
@@ -1,20 +0,0 @@
-#!/bin/bash
-. $(dirname $0)/../../include.rc
-. $(dirname $0)/../../volume.rc
-
-cleanup;
-
-## Start and create a volume
-TEST glusterd;
-TEST pidof glusterd;
-TEST $CLI volume info;
-
-TEST $CLI volume create $V0 $H0:$B0/${V0}{1,2};
-TEST $CLI volume start $V0;
-logdir=`gluster --print-logdir`
-
-build_tester $(dirname $0)/bug-1093594.c -lgfapi
-TEST $(dirname $0)/bug-1093594 $V0 $logdir/bug-1093594.log
-
-cleanup_tester $(dirname $0)/bug-1093594
-cleanup;