[Ocfs2-tools-devel] [PATCH 03/50] libocfs2: Add ocfs2_read_refcount_block().
Tao Ma
tao.ma at oracle.com
Mon Jan 11 07:30:49 PST 2010
From: Joel Becker <joel.becker at oracle.com>
The extent list swap code learns about leaf extent records for refcount
trees, and we now can read refcount blocks.
Signed-off-by: Joel Becker <joel.becker at oracle.com>
Signed-off-by: Tao Ma <tao.ma at oracle.com>
---
include/ocfs2/ocfs2.h | 8 +++
libocfs2/Makefile | 3 +-
libocfs2/refcount.c | 158 +++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 168 insertions(+), 1 deletions(-)
create mode 100644 libocfs2/refcount.c
diff --git a/include/ocfs2/ocfs2.h b/include/ocfs2/ocfs2.h
index 3770a81..68c1dd9 100644
--- a/include/ocfs2/ocfs2.h
+++ b/include/ocfs2/ocfs2.h
@@ -384,6 +384,14 @@ errcode_t ocfs2_read_extent_block_nocheck(ocfs2_filesys *fs, uint64_t blkno,
char *eb_buf);
errcode_t ocfs2_write_extent_block(ocfs2_filesys *fs, uint64_t blkno,
char *eb_buf);
+void ocfs2_swap_refcount_list_to_cpu(ocfs2_filesys *fs, void *obj,
+ struct ocfs2_refcount_list *rl);
+void ocfs2_swap_refcount_block_to_cpu(ocfs2_filesys *fs,
+ struct ocfs2_refcount_block *rb);
+errcode_t ocfs2_read_refcount_block(ocfs2_filesys *fs, uint64_t blkno,
+ char *eb_buf);
+errcode_t ocfs2_read_refcount_block_nocheck(ocfs2_filesys *fs, uint64_t blkno,
+ char *eb_buf);
errcode_t ocfs2_swap_dir_entries_from_cpu(void *buf, uint64_t bytes);
errcode_t ocfs2_swap_dir_entries_to_cpu(void *buf, uint64_t bytes);
void ocfs2_swap_dir_trailer(struct ocfs2_dir_block_trailer *trailer);
diff --git a/libocfs2/Makefile b/libocfs2/Makefile
index 8e94cc3..cafa075 100644
--- a/libocfs2/Makefile
+++ b/libocfs2/Makefile
@@ -76,7 +76,8 @@ CFILES = \
quota.c \
image.c \
xattr.c \
- extent_tree.c
+ extent_tree.c \
+ refcount.c
HFILES = \
bitmap.h \
diff --git a/libocfs2/refcount.c b/libocfs2/refcount.c
new file mode 100644
index 0000000..f8f26c4
--- /dev/null
+++ b/libocfs2/refcount.c
@@ -0,0 +1,158 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * refcount.c
+ *
+ * Functions for the refcount tree structure. Part of the OCFS2 userspace
+ * library.
+ *
+ * Copyright (C) 2009 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.
+ */
+
+#define _XOPEN_SOURCE 600 /* Triggers XOPEN2K in features.h */
+#define _LARGEFILE64_SOURCE
+
+#include <string.h>
+#include <inttypes.h>
+
+#include "ocfs2/byteorder.h"
+#include "ocfs2/ocfs2.h"
+
+
+static void ocfs2_swap_refcount_list_primary(struct ocfs2_refcount_list *rl)
+{
+ rl->rl_count = bswap_16(rl->rl_count);
+ rl->rl_used = bswap_16(rl->rl_used);
+}
+
+static void ocfs2_swap_refcount_list_secondary(ocfs2_filesys *fs, void *obj,
+ struct ocfs2_refcount_list *rl)
+{
+ int i;
+
+ for (i = 0; i < rl->rl_count; i++) {
+ struct ocfs2_refcount_rec *rec = &rl->rl_recs[i];
+
+ if (ocfs2_swap_barrier(fs, obj, rec,
+ sizeof(struct ocfs2_refcount_rec)))
+ break;
+
+ rec->r_cpos = bswap_64(rec->r_cpos);
+ rec->r_clusters = bswap_32(rec->r_clusters);
+ rec->r_refcount = bswap_32(rec->r_refcount);
+ }
+}
+
+void ocfs2_swap_refcount_list_to_cpu(ocfs2_filesys *fs, void *obj,
+ struct ocfs2_refcount_list *rl)
+{
+ if (cpu_is_little_endian)
+ return;
+
+ ocfs2_swap_refcount_list_primary(rl);
+ ocfs2_swap_refcount_list_secondary(fs, obj, rl);
+}
+
+static void ocfs2_swap_refcount_block_header(struct ocfs2_refcount_block *rb)
+{
+
+ rb->rf_suballoc_slot = bswap_16(rb->rf_suballoc_slot);
+ rb->rf_suballoc_bit = bswap_16(rb->rf_suballoc_bit);
+ rb->rf_fs_generation = bswap_32(rb->rf_fs_generation);
+ rb->rf_blkno = bswap_64(rb->rf_blkno);
+ rb->rf_parent = bswap_64(rb->rf_parent);
+ rb->rf_last_eb_blk = bswap_64(rb->rf_last_eb_blk);
+ rb->rf_count = bswap_32(rb->rf_count);
+ rb->rf_flags = bswap_32(rb->rf_flags);
+ rb->rf_clusters = bswap_32(rb->rf_clusters);
+ rb->rf_cpos = bswap_32(rb->rf_cpos);
+}
+
+void ocfs2_swap_refcount_block_to_cpu(ocfs2_filesys *fs,
+ struct ocfs2_refcount_block *rb)
+{
+ if (cpu_is_little_endian)
+ return;
+
+ ocfs2_swap_refcount_block_header(rb);
+ if (rb->rf_flags & OCFS2_REFCOUNT_TREE_FL)
+ ocfs2_swap_extent_list_to_cpu(fs, rb, &rb->rf_list);
+ else
+ ocfs2_swap_refcount_list_to_cpu(fs, rb, &rb->rf_records);
+}
+
+errcode_t ocfs2_read_refcount_block_nocheck(ocfs2_filesys *fs,
+ uint64_t blkno,
+ char *rb_buf)
+{
+ errcode_t ret;
+ char *blk;
+ struct ocfs2_refcount_block *rb;
+
+ if ((blkno < OCFS2_SUPER_BLOCK_BLKNO) ||
+ (blkno > fs->fs_blocks))
+ return OCFS2_ET_BAD_BLKNO;
+
+ ret = ocfs2_malloc_block(fs->fs_io, &blk);
+ if (ret)
+ return ret;
+
+ ret = ocfs2_read_blocks(fs, blkno, 1, blk);
+ if (ret)
+ goto out;
+
+ rb = (struct ocfs2_refcount_block *)blk;
+
+ ret = ocfs2_validate_meta_ecc(fs, blk, &rb->rf_check);
+ if (ret)
+ goto out;
+
+ if (memcmp(rb->rf_signature, OCFS2_REFCOUNT_BLOCK_SIGNATURE,
+ strlen(OCFS2_REFCOUNT_BLOCK_SIGNATURE))) {
+ ret = OCFS2_ET_BAD_EXTENT_BLOCK_MAGIC;
+ goto out;
+ }
+
+ memcpy(rb_buf, blk, fs->fs_blocksize);
+
+ rb = (struct ocfs2_refcount_block *) rb_buf;
+ ocfs2_swap_refcount_block_to_cpu(fs, rb);
+
+out:
+ ocfs2_free(&blk);
+
+ return ret;
+}
+
+errcode_t ocfs2_read_refcount_block(ocfs2_filesys *fs, uint64_t blkno,
+ char *rb_buf)
+{
+ errcode_t ret;
+ struct ocfs2_refcount_block *rb =
+ (struct ocfs2_refcount_block *)rb_buf;
+
+ ret = ocfs2_read_refcount_block_nocheck(fs, blkno, rb_buf);
+
+ /*
+ * Return corruption error here if the user may have a chance
+ * to walk off the end.
+ * XXX: We trust the rb->rf_flags here.
+ */
+ if (ret == 0 &&
+ (((rb->rf_flags & OCFS2_REFCOUNT_TREE_FL) &&
+ rb->rf_list.l_next_free_rec > rb->rf_list.l_count) ||
+ (!(rb->rf_flags & OCFS2_REFCOUNT_TREE_FL) &&
+ rb->rf_records.rl_used > rb->rf_records.rl_count)))
+ ret = OCFS2_ET_CORRUPT_EXTENT_BLOCK;
+
+ return ret;
+}
--
1.5.5
More information about the Ocfs2-tools-devel
mailing list