proper way to do defrag of a mountpoint

Usage: "glusterfs-defrag <MOUNTPOINT>"

there are new features added to distribute with this patch:

* bash# getfattr -n trusted.distribute.linkinfo <file>
  Gives output in the format "<hostname>:<directory>", if there is a
  linkfile present, where hostname is server, directory is backend
  directory where the actual linkfile is present.

* bash# getfattr -n trusted.glusterfs.pathinfo <path>
  Gives layout information if directory, and info about actual
  location of file in backend servers, in the form of
  'hostname:directory'. (TODO: should extend it to all xlators)

* bash# getfattr -n trusted.distribute.fix.layout <path>
  scales out the directory layout in distribute, so when new
  servers are added, layouts are fixed to include them.

* removed 'scale-n-defrag.sh' as its no more required.

* changed 'defrag.sh' to have a feature to specify target bricks,
  so defrag happens to only those nodes. moved the file to
  'glusterfs-defrag', which now gets installed to '${prefix}/bin'

* storage/posix:
  takes new option 'hostname' so it can resolve to same hostname
  given during 'gluster volume create'.
  with 'trusted.glusterfs.pathinfo' posix returns the value in
  'hostname:real_path' format.

Signed-off-by: Amar Tumballi <amar@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 1073 ('gluster defrag <VOLNAME>' fails in mainline)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=1073

5 files changed, 257 insertions, 30 deletions

diff --git a/xlators/cluster/dht/src/dht-common.c b/xlators/cluster/dht/src/dht-common.c
index 1cfeae690..dd2a3f3f1 100644
--- a/xlators/cluster/dht/src/dht-common.c
+++ b/xlators/cluster/dht/src/dht-common.c
@@ -1410,6 +1410,127 @@ err:
 
 
 int
+dht_fix_layout_cbk (call_frame_t *frame, void *cookie,
+                    xlator_t *this, int32_t op_ret, int32_t op_errno)
+{
+        DHT_STACK_UNWIND (getxattr, frame, -1, ENODATA, NULL);
+
+        return 0;
+}
+
+static void
+fill_layout_info (dht_layout_t *layout, char *buf)
+{
+        int i = 0;
+        char tmp_buf[128] = {0,};
+
+        for (i = 0; i < layout->cnt; i++) {
+                snprintf (tmp_buf, 128, "(%s %u %u)",
+                          layout->list[i].xlator->name,
+                          layout->list[i].start,
+                          layout->list[i].stop);
+                if (i)
+                        strcat (buf, " ");
+                strcat (buf, tmp_buf);
+        }
+}
+
+int
+dht_pathinfo_getxattr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
+                           int op_ret, int op_errno, dict_t *xattr)
+{
+	dht_local_t  *local = NULL;
+        int ret = 0;
+        int flag = 0;
+        int this_call_cnt = 0;
+        char *value_got = NULL;
+        char  layout_buf[8192] = {0,};
+        char  xattr_buf[8192 + 1024] = {0,};
+        dict_t *dict = NULL;
+
+        local = frame->local;
+
+        if (op_ret != -1) {
+                ret = dict_get_str (xattr, GF_XATTR_PATHINFO_KEY, &value_got);
+                if (!ret) {
+                        if (!local->pathinfo)
+                                local->pathinfo = GF_CALLOC (8192, sizeof (char),
+                                                             gf_common_mt_char);
+                        if (local->pathinfo)
+                                strcat (local->pathinfo, value_got);
+                }
+        }
+
+        this_call_cnt = dht_frame_return (frame);
+        if (is_last_call (this_call_cnt)) {
+                if (local->layout->cnt > 1) {
+                        /* Set it for directory */
+                        fill_layout_info (local->layout, layout_buf);
+                        flag = 1;
+                }
+
+                dict = dict_new ();
+
+                if (flag && local->pathinfo)
+                        snprintf (xattr_buf, 9216, "((%s %s) (%s-layout %s))",
+                                  this->name, local->pathinfo, this->name,
+                                  layout_buf);
+                else if (local->pathinfo)
+                        snprintf (xattr_buf, 9216, "(%s %s)",
+                                  this->name, local->pathinfo);
+                else if (flag)
+                        snprintf (xattr_buf, 9216, "(%s-layout %s)",
+                                  this->name, layout_buf);
+
+                ret = dict_set_str (dict, GF_XATTR_PATHINFO_KEY,
+                                    xattr_buf);
+
+                if (local->pathinfo)
+                        GF_FREE (local->pathinfo);
+                GF_FREE (local->key);
+
+                DHT_STACK_UNWIND (getxattr, frame, op_ret, op_errno, dict);
+
+                if (dict)
+                        dict_unref (dict);
+
+                return 0;
+        }
+
+        if (local->pathinfo)
+                strcat (local->pathinfo, " Link: ");
+
+        /* This will happen if there pending */
+        STACK_WIND (frame, dht_pathinfo_getxattr_cbk, local->hashed_subvol,
+                    local->hashed_subvol->fops->getxattr,
+                    &local->loc, local->key);
+
+        return 0;
+}
+
+int
+dht_linkinfo_getxattr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
+                           int op_ret, int op_errno, dict_t *xattr)
+{
+        int   ret   = 0;
+        char *value = NULL;
+
+        if (op_ret != -1) {
+                ret = dict_get_str (xattr, GF_XATTR_PATHINFO_KEY, &value);
+                if (!ret) {
+                        ret = dict_set_str (xattr, GF_XATTR_LINKINFO_KEY, value);
+                        if (!ret)
+                                gf_log (this->name, GF_LOG_TRACE,
+                                        "failed to set linkinfo");
+                }
+        }
+
+        DHT_STACK_UNWIND (getxattr, frame, op_ret, op_errno, xattr);
+
+        return 0;
+}
+
+int
 dht_getxattr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 		  int op_ret, int op_errno, dict_t *xattr)
 {
@@ -1429,9 +1550,14 @@ int
 dht_getxattr (call_frame_t *frame, xlator_t *this,
 	      loc_t *loc, const char *key)
 {
-	xlator_t     *subvol = NULL;
-        int           op_errno = -1;
-
+	xlator_t     *subvol        = NULL;
+	xlator_t     *hashed_subvol = NULL;
+	xlator_t     *cached_subvol = NULL;
+	dht_conf_t   *conf          = NULL;
+	dht_local_t  *local         = NULL;
+        dht_layout_t *layout        = NULL;
+        int           op_errno      = -1;
+        int           ret           = 0;
 
         VALIDATE_OR_GOTO (frame, err);
         VALIDATE_OR_GOTO (this, err);
@@ -1439,6 +1565,91 @@ dht_getxattr (call_frame_t *frame, xlator_t *this,
         VALIDATE_OR_GOTO (loc->inode, err);
         VALIDATE_OR_GOTO (loc->path, err);
 
+        conf   = this->private;
+        layout = dht_layout_get (this, loc->inode);
+        if (key && (strcmp (key, GF_XATTR_PATHINFO_KEY) == 0)) {
+                hashed_subvol = dht_subvol_get_hashed (this, loc);
+                cached_subvol = dht_subvol_get_cached (this, loc->inode);
+
+                local = dht_local_init (frame);
+                if (!local) {
+                        op_errno = ENOMEM;
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Out of memory");
+                        goto err;
+                }
+
+                ret = loc_dup (loc, &local->loc);
+                if (ret == -1) {
+                        op_errno = ENOMEM;
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Out of memory");
+                        goto err;
+                }
+                local->key = gf_strdup (key);
+                if (!local->key) {
+                        op_errno = ENOMEM;
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Out of memory");
+                        goto err;
+                }
+                local->layout = layout;
+
+                local->call_cnt = 1;
+                if (hashed_subvol != cached_subvol) {
+                        local->call_cnt = 2;
+                        local->hashed_subvol = hashed_subvol;
+                }
+
+                STACK_WIND (frame, dht_pathinfo_getxattr_cbk, cached_subvol,
+                            cached_subvol->fops->getxattr, loc, key);
+
+                return 0;
+        }
+        if (key && (strcmp (key, GF_XATTR_LINKINFO_KEY) == 0)) {
+                hashed_subvol = dht_subvol_get_hashed (this, loc);
+                cached_subvol = dht_subvol_get_cached (this, loc->inode);
+                if (hashed_subvol == cached_subvol) {
+                        op_errno = ENODATA;
+                        goto err;
+                }
+                if (hashed_subvol) {
+                        STACK_WIND (frame, dht_linkinfo_getxattr_cbk, hashed_subvol,
+                                    hashed_subvol->fops->getxattr, loc,
+                                    GF_XATTR_PATHINFO_KEY);
+                        return 0;
+                }
+                op_errno = ENODATA;
+                goto err;
+        }
+        if (key && (strcmp (key, GF_XATTR_FIX_LAYOUT_KEY) == 0)) {
+                if (layout->cnt < conf->subvolume_cnt) {
+                        gf_log (this->name, GF_LOG_INFO,
+                                "expanding layout of %s from %d to %d",
+                                loc->path, layout->cnt, conf->subvolume_cnt);
+                        local = dht_local_init (frame);
+                        if (!local) {
+                                op_errno = ENOMEM;
+                                gf_log (this->name, GF_LOG_ERROR,
+                                        "Out of memory");
+                                goto err;
+                        }
+
+                        ret = loc_dup (loc, &local->loc);
+                        if (ret == -1) {
+                                op_errno = ENOMEM;
+                                gf_log (this->name, GF_LOG_ERROR,
+                                        "Out of memory");
+                                goto err;
+                        }
+                        local->layout = layout;
+                        dht_selfheal_new_directory (frame, dht_fix_layout_cbk,
+                                                    layout);
+                        return 0;
+                }
+                op_errno = ENODATA;
+                goto err;
+        }
 	subvol = dht_subvol_get_cached (this, loc->inode);
 	if (!subvol) {
 		gf_log (this->name, GF_LOG_DEBUG,
diff --git a/xlators/cluster/dht/src/dht-common.h b/xlators/cluster/dht/src/dht-common.h
index b361f1442..d5a5c7b2c 100644
--- a/xlators/cluster/dht/src/dht-common.h
+++ b/xlators/cluster/dht/src/dht-common.h
@@ -27,6 +27,7 @@
 #ifndef _DHT_H
 #define _DHT_H
 
+#define GF_XATTR_FIX_LAYOUT_KEY   "trusted.distribute.fix.layout"
 #define GF_DHT_LOOKUP_UNHASHED_ON   1
 #define GF_DHT_LOOKUP_UNHASHED_AUTO 2
 
@@ -116,6 +117,10 @@ struct dht_local {
 	int32_t flags;
 	mode_t  mode;
 	dev_t   rdev;
+
+        /* need for file-info */
+        char   *pathinfo;
+        char   *key;
 };
 typedef struct dht_local dht_local_t;
 
diff --git a/xlators/mount/fuse/src/fuse-bridge.c b/xlators/mount/fuse/src/fuse-bridge.c
index 142ff064e..9c9dff0b9 100644
--- a/xlators/mount/fuse/src/fuse-bridge.c
+++ b/xlators/mount/fuse/src/fuse-bridge.c
@@ -2629,11 +2629,11 @@ fuse_xattr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                                         state->loc.path, strerror (op_errno));
                         }
                 } else {
-                        gf_log ("glusterfs-fuse", GF_LOG_WARNING,
-                                "%"PRIu64": %s() %s => -1 (%s)",
+                        gf_log ("glusterfs-fuse", GF_LOG_DEBUG,
+                                "%"PRIu64": %s(%s) %s => -1 (%s)",
                                 frame->root->unique,
-                                gf_fop_list[frame->root->op], state->loc.path,
-                                strerror (op_errno));
+                                gf_fop_list[frame->root->op], state->name,
+                                state->loc.path, strerror (op_errno));
                 } /* if(op_errno!= ENODATA)...else */
 
                 send_fuse_err (this, finh, op_errno);
diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c
index 7c0d165ac..2810bbd6a 100644
--- a/xlators/storage/posix/src/posix.c
+++ b/xlators/storage/posix/src/posix.c
@@ -3032,6 +3032,7 @@ posix_getxattr (call_frame_t *frame, xlator_t *this,
         size_t   size           = 0;
         size_t   remaining_size = 0;
         char     key[1024]      = {0,};
+        char     host_buf[1024] = {0,};
         char     gen_key[1024]  = {0,};
         char *   value          = NULL;
         char *   list           = NULL;
@@ -3072,18 +3073,18 @@ posix_getxattr (call_frame_t *frame, xlator_t *this,
         }
 
 	if (loc->inode && IA_ISREG (loc->inode->ia_type) && name &&
-	    (strcmp (name, "trusted.glusterfs.location") == 0)) {
-                ret = dict_set_static_ptr (dict, 
-                                           "trusted.glusterfs.location", 
-                                           priv->hostname);
+	    (strcmp (name, GF_XATTR_PATHINFO_KEY) == 0)) {
+                snprintf (host_buf, 1024, "%s:%s", priv->hostname,
+                          real_path);
+                ret = dict_set_str (dict, GF_XATTR_PATHINFO_KEY,
+                                    host_buf);
                 if (ret < 0) {
                         gf_log (this->name, GF_LOG_WARNING,
-                                "could not set hostname (%s) in dictionary",
-                                priv->hostname);
+                                "could not set value (%s) in dictionary",
+                                host_buf);
                 }
                 goto done;
 	}
-        
 
         size = sys_llistxattr (real_path, NULL, 0);
         if (size == -1) {
@@ -4260,17 +4261,16 @@ mem_acct_init (xlator_t *this)
 int
 init (xlator_t *this)
 {
-        int                    ret      = 0;
-        int                    op_ret   = -1;
-	gf_boolean_t           tmp_bool = 0;
-        struct stat            buf      = {0,};
-        struct posix_private * _private = NULL;
-        data_t *               dir_data = NULL;
-	data_t *               tmp_data = NULL;
-        uint64_t               time64   = 0;
-
-        int dict_ret = 0;
-        int32_t janitor_sleep;
+        struct posix_private  *_private      = NULL;
+        data_t                *dir_data      = NULL;
+	data_t                *tmp_data      = NULL;
+        struct stat            buf           = {0,};
+	gf_boolean_t           tmp_bool      = 0;
+        uint64_t               time64        = 0;
+        int                    dict_ret      = 0;
+        int                    ret           = 0;
+        int                    op_ret        = -1;
+        int32_t                janitor_sleep = 0;
 
         dir_data = dict_get (this->options, "directory");
 
@@ -4370,10 +4370,19 @@ init (xlator_t *this)
 
         LOCK_INIT (&_private->lock);
 
-        ret = gethostname (_private->hostname, 256);
-        if (ret < 0) {
-                gf_log (this->name, GF_LOG_WARNING, 
-                        "could not find hostname (%s)", strerror (errno));
+        ret = dict_get_str (this->options, "hostname", &_private->hostname);
+        if (ret) {
+                _private->hostname = GF_CALLOC (256, sizeof (char),
+                                                gf_common_mt_char);
+                if (!_private->hostname) {
+                        gf_log (this->name, GF_LOG_ERROR, "not enough memory");
+                        goto out;
+                }
+                ret = gethostname (_private->hostname, 256);
+                if (ret < 0) {
+                        gf_log (this->name, GF_LOG_WARNING,
+                                "could not find hostname (%s)", strerror (errno));
+                }
         }
 
         _private->export_statfs = 1;
@@ -4574,6 +4583,8 @@ struct volume_options options[] = {
 	  .type = GF_OPTION_TYPE_BOOL },
 	{ .key  = {"directory"},
 	  .type = GF_OPTION_TYPE_PATH },
+	{ .key  = {"hostname"},
+	  .type = GF_OPTION_TYPE_ANY },
 	{ .key  = {"export-statfs-size"},
 	  .type = GF_OPTION_TYPE_BOOL },
 	{ .key  = {"mandate-attribute"},
diff --git a/xlators/storage/posix/src/posix.h b/xlators/storage/posix/src/posix.h
index 0295a1f48..2aff0a6ca 100644
--- a/xlators/storage/posix/src/posix.h
+++ b/xlators/storage/posix/src/posix.h
@@ -73,7 +73,7 @@ struct posix_private {
 
         gf_lock_t lock;
 
-        char   hostname[256];
+        char   *hostname;
         /* Statistics, provides activity of the server */
 
 	struct timeval prev_fetch_time;