add example Lustre plugin for adding lustre stripe info to the DBs

Author: bertschinger

contrib/lustre_plugin.c

@@ -0,0 +1,349 @@
+/*
+This file is part of GUFI, which is part of MarFS, which is released
+under the BSD license.
+
+
+Copyright (c) 2017, Los Alamos National Security (LANS), LLC
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions and the following disclaimer in the documentation and/or
+other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its contributors
+may be used to endorse or promote products derived from this software without
+specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+From Los Alamos National Security, LLC:
+LA-CC-15-039
+
+Copyright (c) 2017, Los Alamos National Security, LLC All rights reserved.
+Copyright 2017. Los Alamos National Security, LLC. This software was produced
+under U.S. Government contract DE-AC52-06NA25396 for Los Alamos National
+Laboratory (LANL), which is operated by Los Alamos National Security, LLC for
+the U.S. Department of Energy. The U.S. Government has rights to use,
+reproduce, and distribute this software.  NEITHER THE GOVERNMENT NOR LOS
+ALAMOS NATIONAL SECURITY, LLC MAKES ANY WARRANTY, EXPRESS OR IMPLIED, OR
+ASSUMES ANY LIABILITY FOR THE USE OF THIS SOFTWARE.  If software is
+modified to produce derivative works, such modified software should be
+clearly marked, so as not to confuse it with the version available from
+LANL.
+
+THIS SOFTWARE IS PROVIDED BY LOS ALAMOS NATIONAL SECURITY, LLC AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL LOS ALAMOS NATIONAL SECURITY, LLC OR
+CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+OF SUCH DAMAGE.
+*/
+
+/*
+ * An example Lustre plugin for GUFI.
+ *
+ * I compiled this with:
+ *
+ *     # set based on the lustre source location on your machine:
+ *     $ export LUSTRE_INCLUDE_DIR=/home/$USER/git/lustre-release/lustre/include
+ *     $ export LUSTRE_LIBRARY_DIR=/home/$USER/git/lustre-release/lustre/utils/.libs
+ *
+ *     $ cd contrib
+ *
+ *     $ gcc -g -O0 -c -fPIC -I../build/deps/sqlite3/include -I../include -I$LUSTRE_INCLUDE_DIR -I$LUSTRE_INCLUDE_DIR/uapi lustre_plugin.c
+ *
+ *     $ gcc -shared -o liblustre_plugin.so lustre_plugin.o -L$LUSTRE_LIBRARY_DIR -llustreapi
+ *
+ *  Note that this includes the sqlite3 header from the GUFI sources, but this should not
+ *  statically link sqlite3. Instead, it should dynamically link to the sqlite3 symbols in
+ *  the main GUFI binary when this code is dlopen()ed.
+ *
+ *  I ran this with:
+ *      $ LD_LIBRARY_PATH=$LUSTRE_LIBRARY_DIR ./src/gufi_dir2index -U ../contrib/liblustre_plugin.so -n1 /mnt/lustre /tmp/gufi_index/
+ */
+
+#include <errno.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "plugin.h"
+#include "sqlite3.h"
+#include "lustre/lustreapi.h"
+
+static char *my_basename(char *path) {
+    char *base = path;
+    char *p = path;
+    int next_component = 0;
+
+    while (*p) {
+        if (next_component) {
+            base = p;
+            next_component = 0;
+        }
+
+        if (*p == '/') {
+            next_component = 1;
+        }
+
+        p++;
+    }
+
+    return base;
+}
+
+/*
+ * This struct tracks the number of components seen on each OST. For each file
+ * processed, and for each component of that file, add one to the count for
+ * that particular OST.
+ */
+struct stripe_tracker {
+    /*
+     * num_components[i] stores the number of components that have been seen
+     * on the OST with index i.
+     */
+    uint64_t *stripe_count;
+    /*
+     * Stores the size of the num_components table. This needs to grow when we see a
+     * new OST number that is higher than the maximum index in the table so far.
+     */
+    uint32_t array_size;
+    /*
+     * Tracks the highest OST index seen. This will likely be smaller than the
+     * array size, so separately tracking it means we don't have to loop through the
+     * useless high indexes in the stripe_count array when saving the stripe info
+     * to the database.
+     */
+    uint32_t max_ost_idx;
+};
+
+/*
+ * Allocate and Initialize a new stripe_tracker.
+ */
+static struct stripe_tracker *new_stripe_tracker(void) {
+    uint32_t initial_size = 64;
+
+    struct stripe_tracker *new = malloc(sizeof *new);
+    if (!new) {
+        return NULL;
+    }
+
+    new->stripe_count = calloc(initial_size, sizeof(*new->stripe_count));
+    if (!new->stripe_count) {
+        free(new);
+        return NULL;
+    }
+
+    new->array_size = initial_size;
+
+    new->max_ost_idx = 0;
+
+    return new;
+}
+
+/*
+ * Clean up a stripe_tracker, freeing its allocations.
+ */
+static void destroy_stripe_tracker(struct stripe_tracker *p) {
+    if (p) {
+        free(p->stripe_count);
+    }
+
+    free(p);
+}
+
+/*
+ * If necessary, grow the stripe_count array in `s` to be large enough to
+ * accomodate `ost_index`.
+ *
+ * Returns 0 if growing succeeded, or 1 if it failed.
+ */
+static int grow_stripe_tracker(struct stripe_tracker *s, uint32_t ost_index) {
+    if (ost_index > s->max_ost_idx) {
+        s->max_ost_idx = ost_index;
+    }
+    if (ost_index < s->array_size) {
+        /* Nothing needs to be done: yay! */
+        return 0;
+    }
+
+    uint32_t new_size = s->array_size;
+
+    while (ost_index >= new_size) {
+        if (new_size >= UINT32_MAX / 2) {
+            /* In case we somehow get a filesystem with an insane number of OSTs,
+             * don't let that overflow and ruin our array: */
+            return 1;
+        }
+        new_size *= 2;
+    }
+
+    uint64_t *new_array = realloc(s->stripe_count, new_size);
+    if (!new_array) {
+        return 1;
+    }
+
+    /* The new space is not initialized, so do that now: */
+    memset(new_array + s->array_size, 0, new_size - s->array_size);
+
+    s->stripe_count = new_array;
+    s->array_size = new_size;
+
+    return 0;
+}
+
+/*
+ * Given the `stripe_array` which contains `stripe_count` stripes, increment
+ * the count for each OST that the stripe lives on.
+ */
+static void track_file_stripes(struct stripe_tracker *s,
+                               struct lov_user_ost_data_v1 *stripe_array,
+                               uint16_t stripe_count) {
+    for (int i = 0; i < stripe_count; i++) {
+        uint32_t ost_index = stripe_array[i].l_ost_idx;
+        if (grow_stripe_tracker(s, ost_index)) {
+            /* Just give up if we couldn't grow the stripe array large enough :( */
+            fprintf(stderr, "lustre plugin: could not allocate memory, information may be incomplete");
+            return;
+        }
+
+        s->stripe_count[ost_index] += 1;
+    }
+}
+
+/*
+ * Set up initial state for tracking Lustre stripe info.
+ */
+void *db_init(sqlite3 *db) {
+    struct stripe_tracker *state = new_stripe_tracker();
+    if (!state) {
+        fprintf(stderr, "lustre plugin: could not allocate memory to track stripe info");
+        return NULL;
+    }
+
+    static const char text[] = "CREATE TABLE lustre_summary (ost_index INTEGER PRIMARY KEY, num_files INTEGER);";
+    char *error;
+
+    int res = sqlite3_exec(db, text, NULL, NULL, &error);
+    if (res != SQLITE_OK) {
+        fprintf(stderr, "lustre plugin: db_init(): error executing statement: %d %s\n", res, error);
+    }
+
+    sqlite3_free(error);
+
+    return state;
+}
+
+/*
+ * Save stripe tracking info to the database and clean up state.
+ */
+void db_exit(sqlite3 *db, void *user_data) {
+    struct stripe_tracker *state = (struct stripe_tracker *) user_data;
+
+    for (uint32_t i = 0; i <= state->max_ost_idx; i++) {
+        char *text = sqlite3_mprintf("INSERT INTO %s VALUES(%" PRIu32 ", %" PRIu64 ");",
+                "lustre_summary", i, state->stripe_count[i]);
+        char *error;
+
+        int res = sqlite3_exec(db, text, NULL, NULL, &error);
+        if (res != SQLITE_OK) {
+            fprintf(stderr, "lustre plugin: db_exit(): error executing statement: %d %s\n",
+                    res, error);
+        }
+
+        sqlite3_free(text);
+        sqlite3_free(error);
+    }
+
+    destroy_stripe_tracker(state);
+};
+
+/*
+ * This method of determining the maximum possible size of a `lov_user_md` was suggested by
+ *      man 3 llapi_file_get_stripe
+ */
+static const size_t v1_size = sizeof(struct lov_user_md_v1) + LOV_MAX_STRIPE_COUNT * sizeof(struct lov_user_ost_data_v1);
+static const size_t v3_size = sizeof(struct lov_user_md_v3) + LOV_MAX_STRIPE_COUNT * sizeof(struct lov_user_ost_data_v1);
+static const size_t lum_size = v1_size > v3_size ? v1_size : v3_size;
+
+static void *alloc_lum() {
+    return calloc(1, lum_size);
+}
+
+void process_file(char *path, sqlite3 *db, void *user_data) {
+    sqlite3_stmt *statement;
+
+    struct lov_user_md *layout_info = alloc_lum();
+
+    int res = llapi_file_get_stripe(path, layout_info);
+
+    if (res) {
+        fprintf(stderr, "lustre plugin: error getting stripe info for %s: %s\n",
+                path, strerror(errno));
+        free(layout_info);
+        return;
+    }
+
+    char *text = sqlite3_mprintf("UPDATE entries SET ossint4 = %d where name = '%q';",
+            layout_info->lmm_stripe_size, my_basename(path));
+    char *error;
+
+    res = sqlite3_exec(db, text, NULL, NULL, &error);
+    if (res != SQLITE_OK) {
+        fprintf(stderr, "lustre plugin: process_file(): error executing statement: %d %s\n",
+                res, error);
+        goto out;
+    }
+
+    struct lov_user_ost_data_v1 *stripe_array;
+    uint16_t stripe_count;
+
+    if (layout_info->lmm_magic == LOV_USER_MAGIC_V1) {
+        struct lov_user_md_v1 *v1= (struct lov_user_md_v1 *) layout_info;
+        stripe_array = v1->lmm_objects;
+        stripe_count = v1->lmm_stripe_count;
+    } else if (layout_info->lmm_magic == LOV_USER_MAGIC_V3) {
+        struct lov_user_md_v3 *v3= (struct lov_user_md_v3 *) layout_info;
+        stripe_array = v3->lmm_objects;
+        stripe_count = v3->lmm_stripe_count;
+    } else {
+        fprintf(stderr, "lustre plugin: unknown layout format on file %s: %d\n", path, layout_info->lmm_magic);
+        goto out;
+    }
+
+    struct stripe_tracker *tracker = (struct stripe_tracker *) user_data;
+    track_file_stripes(tracker, stripe_array, stripe_count);
+
+  out:
+    free(layout_info);
+    sqlite3_free(error);
+    sqlite3_free(text);
+}
+
+struct plugin_operations exported_operations = {
+    .db_init = db_init,
+    .process_dir = NULL,
+    .process_file = process_file,
+    .db_exit = db_exit,
+};