[Ocfs2-tools-devel] [PATCH 16/22] tunefs rework: Add feature_backup_super.c
Joel Becker
joel.becker at oracle.com
Fri Jul 25 19:07:54 PDT 2008
Enable and disable the backup superblock feature.
This is the 'backup-super' key to the tunefs option '--fs-features', as
well as the tunefs option '--backup-super'.
Signed-off-by: Joel Becker <joel.becker at oracle.com>
---
tunefs.ocfs2/feature_backup_super.c | 229 +++++++++++++++++++++++++++++++++++
1 files changed, 229 insertions(+), 0 deletions(-)
create mode 100644 tunefs.ocfs2/feature_backup_super.c
diff --git a/tunefs.ocfs2/feature_backup_super.c b/tunefs.ocfs2/feature_backup_super.c
new file mode 100644
index 0000000..a8af858
--- /dev/null
+++ b/tunefs.ocfs2/feature_backup_super.c
@@ -0,0 +1,229 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * feature_backup_super.c
+ *
+ * ocfs2 tune utility to enable and disable the backup superblock feature.
+ *
+ * Copyright (C) 2004, 2008 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <inttypes.h>
+
+#include "ocfs2/ocfs2.h"
+
+#include "libocfs2ne.h"
+
+
+static errcode_t empty_backup_supers(ocfs2_filesys *fs)
+{
+ errcode_t ret;
+ int num;
+ uint64_t blocks[OCFS2_MAX_BACKUP_SUPERBLOCKS];
+
+ num = ocfs2_get_backup_super_offsets(fs, blocks,
+ ARRAY_SIZE(blocks));
+ if (!num)
+ return 0;
+
+ ret = ocfs2_clear_backup_super_list(fs, blocks, num);
+ if (ret)
+ tcom_err(ret, "while freeing backup superblock locations");
+
+ return ret;
+}
+
+static errcode_t fill_backup_supers(ocfs2_filesys *fs)
+{
+ errcode_t ret;
+ int num;
+ uint64_t blocks[OCFS2_MAX_BACKUP_SUPERBLOCKS];
+
+ num = ocfs2_get_backup_super_offsets(fs, blocks,
+ ARRAY_SIZE(blocks));
+ ret = ocfs2_set_backup_super_list(fs, blocks, num);
+ if (ret)
+ tcom_err(ret, "while backing up the superblock");
+
+ return ret;
+}
+
+static int disable_backup_super(ocfs2_filesys *fs, int flags)
+{
+ errcode_t err = 0;
+ struct ocfs2_super_block *super = OCFS2_RAW_SB(fs->fs_super);
+
+ if (!OCFS2_HAS_COMPAT_FEATURE(super,
+ OCFS2_FEATURE_COMPAT_BACKUP_SB)) {
+ verbosef(VL_APP,
+ "Backup superblock feature is not enabled; "
+ "nothing to disable\n");
+ goto out;
+ }
+
+ if (!tunefs_interact("Disable the backup superblock feature on "
+ "device \"%s\"? ",
+ fs->fs_devname))
+ goto out;
+
+ tunefs_block_signals();
+ err = empty_backup_supers(fs);
+ if (!err) {
+ super->s_feature_compat &= ~OCFS2_FEATURE_COMPAT_BACKUP_SB;
+ err = ocfs2_write_super(fs);
+ if (err)
+ tcom_err(err,
+ "while writing out the superblock\n"
+ "Unable to disable the backup superblock "
+ "feature on device \"%s\"",
+ fs->fs_devname);
+ }
+ tunefs_unblock_signals();
+
+out:
+ return err;
+}
+
+static errcode_t load_global_bitmap(ocfs2_filesys *fs,
+ ocfs2_cached_inode** inode)
+{
+ errcode_t ret;
+ uint64_t blkno;
+
+ ret = ocfs2_lookup_system_inode(fs, GLOBAL_BITMAP_SYSTEM_INODE,
+ 0, &blkno);
+ if (ret)
+ goto bail;
+
+ ret = ocfs2_read_cached_inode(fs, blkno, inode);
+ if (ret)
+ goto bail;
+
+ ret = ocfs2_load_chain_allocator(fs, *inode);
+
+bail:
+ return ret;
+}
+
+static errcode_t check_backup_offsets(ocfs2_filesys *fs)
+{
+
+ errcode_t ret;
+ int i, num, val, failed = 0;
+ ocfs2_cached_inode *chain_alloc = NULL;
+ uint64_t blocks[OCFS2_MAX_BACKUP_SUPERBLOCKS];
+
+ num = ocfs2_get_backup_super_offsets(fs, blocks,
+ ARRAY_SIZE(blocks));
+ if (!num) {
+ ret = 1;
+ errorf("Volume on device \"%s\" is too small to contain "
+ "backup superblocks\n",
+ fs->fs_devname);
+ goto bail;
+ }
+
+ ret = load_global_bitmap(fs, &chain_alloc);
+ if (ret) {
+ tcom_err(ret, "while loading the global bitmap");
+ goto bail;
+ }
+
+ for (i = 0; i < num; i++) {
+ ret = ocfs2_bitmap_test(chain_alloc->ci_chains,
+ ocfs2_blocks_to_clusters(fs, blocks[i]),
+ &val);
+ if (ret) {
+ tcom_err(ret,
+ "looking up backup superblock locations "
+ "in the global bitmap");
+ goto bail;
+ }
+
+ if (val) {
+ verbosef(VL_APP,
+ "Backup superblock location %d at block "
+ "%"PRIu64" is in use\n", i, blocks[i]);
+ /* in order to verify all the block in the 'blocks',
+ * we don't stop the loop here.
+ */
+ failed = 1;
+ }
+ }
+
+ if (failed) {
+ ret = 1;
+ errorf("One or more backup superblock locations are "
+ "already in use\n");
+ } else
+ ret = 0;
+
+ if (chain_alloc)
+ ocfs2_free_cached_inode(fs, chain_alloc);
+
+bail:
+ return ret;
+}
+
+static int enable_backup_super(ocfs2_filesys *fs, int flags)
+{
+ errcode_t err = 0;
+ struct ocfs2_super_block *super = OCFS2_RAW_SB(fs->fs_super);
+
+ if (OCFS2_HAS_COMPAT_FEATURE(super,
+ OCFS2_FEATURE_COMPAT_BACKUP_SB)) {
+ verbosef(VL_APP,
+ "Backup superblock feature is already enabled; "
+ "nothing to enable\n");
+ goto out;
+ }
+
+ if (!tunefs_interact("Enable the backup superblock feature on "
+ "device \"%s\"? ",
+ fs->fs_devname))
+ goto out;
+
+ tunefs_block_signals();
+ err = check_backup_offsets(fs);
+ if (!err)
+ err = fill_backup_supers(fs);
+ if (!err) {
+ super->s_feature_compat |= OCFS2_FEATURE_COMPAT_BACKUP_SB;
+ err = ocfs2_write_super(fs);
+ if (err)
+ tcom_err(err, "while writing out the superblock\n");
+ }
+ tunefs_unblock_signals();
+
+ if (err)
+ errorf("Unable to enable the backup superblock feature on "
+ "device \"%s\"\n",
+ fs->fs_devname);
+out:
+ return err;
+}
+
+DEFINE_TUNEFS_FEATURE_COMPAT(backup_super,
+ OCFS2_FEATURE_COMPAT_BACKUP_SB,
+ TUNEFS_FLAG_RW | TUNEFS_FLAG_ALLOCATION,
+ enable_backup_super,
+ disable_backup_super);
+
+#ifdef DEBUG_EXE
+int main(int argc, char *argv[])
+{
+ return tunefs_feature_main(argc, argv, &backup_super_feature);
+}
+#endif
--
1.5.6.3
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