From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
These helpers enable userspace to iterate all the space map information
for a file. The iteration function uses GETBMAPX.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
scrub/Makefile | 2 +
scrub/filemap.c | 157 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
scrub/filemap.h | 39 ++++++++++++++
3 files changed, 198 insertions(+)
create mode 100644 scrub/filemap.c
create mode 100644 scrub/filemap.h
diff --git a/scrub/Makefile b/scrub/Makefile
index 24e0c44..a3534e6 100644
--- a/scrub/Makefile
+++ b/scrub/Makefile
@@ -18,6 +18,7 @@ endif # scrub_prereqs
HFILES = \
common.h \
disk.h \
+filemap.h \
inodes.h \
spacemap.h \
xfs_scrub.h
@@ -25,6 +26,7 @@ xfs_scrub.h
CFILES = \
common.c \
disk.c \
+filemap.c \
inodes.c \
phase1.c \
spacemap.c \
diff --git a/scrub/filemap.c b/scrub/filemap.c
new file mode 100644
index 0000000..f42a6ba
--- /dev/null
+++ b/scrub/filemap.c
@@ -0,0 +1,157 @@
+/*
+ * Copyright (C) 2018 Oracle. All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+#include <stdio.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/statvfs.h>
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "path.h"
+#include "xfs_scrub.h"
+#include "common.h"
+#include "filemap.h"
+
+/*
+ * These routines provide a simple interface to query the block
+ * mappings of the fork of a given inode via GETBMAPX and call a
+ * function to iterate each mapping result.
+ */
+
+#define BMAP_NR 2048
+
+/* Iterate all the extent block mappings between the key and fork end. */
+bool
+xfs_iterate_filemaps(
+ struct scrub_ctx *ctx,
+ const char *descr,
+ int fd,
+ int whichfork,
+ struct xfs_bmap *key,
+ xfs_bmap_iter_fn fn,
+ void *arg)
+{
+ struct fsxattr fsx;
+ struct getbmapx *map;
+ struct getbmapx *p;
+ struct xfs_bmap bmap;
+ char bmap_descr[DESCR_BUFSZ];
+ bool moveon = true;
+ xfs_off_t new_off;
+ int getxattr_type;
+ int i;
+ int error;
+
+ switch (whichfork) {
+ case XFS_ATTR_FORK:
+ snprintf(bmap_descr, DESCR_BUFSZ, _("%s attr"), descr);
+ break;
+ case XFS_COW_FORK:
+ snprintf(bmap_descr, DESCR_BUFSZ, _("%s CoW"), descr);
+ break;
+ case XFS_DATA_FORK:
+ snprintf(bmap_descr, DESCR_BUFSZ, _("%s data"), descr);
+ break;
+ default:
+ abort();
+ }
+
+ map = calloc(BMAP_NR, sizeof(struct getbmapx));
+ if (!map) {
+ str_errno(ctx, bmap_descr);
+ return false;
+ }
+
+ map->bmv_offset = BTOBB(key->bm_offset);
+ map->bmv_block = BTOBB(key->bm_physical);
+ if (key->bm_length == 0)
+ map->bmv_length = ULLONG_MAX;
+ else
+ map->bmv_length = BTOBB(key->bm_length);
+ map->bmv_count = BMAP_NR;
+ map->bmv_iflags = BMV_IF_NO_DMAPI_READ | BMV_IF_PREALLOC |
+ BMV_IF_NO_HOLES;
+ switch (whichfork) {
+ case XFS_ATTR_FORK:
+ getxattr_type = XFS_IOC_FSGETXATTRA;
+ map->bmv_iflags |= BMV_IF_ATTRFORK;
+ break;
+ case XFS_COW_FORK:
+ map->bmv_iflags |= BMV_IF_COWFORK;
+ getxattr_type = FS_IOC_FSGETXATTR;
+ break;
+ case XFS_DATA_FORK:
+ getxattr_type = FS_IOC_FSGETXATTR;
+ break;
+ default:
+ abort();
+ }
+
+ error = ioctl(fd, getxattr_type, &fsx);
+ if (error < 0) {
+ str_errno(ctx, bmap_descr);
+ moveon = false;
+ goto out;
+ }
+
+ while ((error = ioctl(fd, XFS_IOC_GETBMAPX, map)) == 0) {
+ for (i = 0, p = &map[i + 1]; i < map->bmv_entries; i++, p++) {
+ bmap.bm_offset = BBTOB(p->bmv_offset);
+ bmap.bm_physical = BBTOB(p->bmv_block);
+ bmap.bm_length = BBTOB(p->bmv_length);
+ bmap.bm_flags = p->bmv_oflags;
+ moveon = fn(ctx, bmap_descr, fd, whichfork, &fsx,
+ &bmap, arg);
+ if (!moveon)
+ goto out;
+ if (xfs_scrub_excessive_errors(ctx)) {
+ moveon = false;
+ goto out;
+ }
+ }
+
+ if (map->bmv_entries == 0)
+ break;
+ p = map + map->bmv_entries;
+ if (p->bmv_oflags & BMV_OF_LAST)
+ break;
+
+ new_off = p->bmv_offset + p->bmv_length;
+ map->bmv_length -= new_off - map->bmv_offset;
+ map->bmv_offset = new_off;
+ }
+
+ /*
+ * Pre-reflink filesystems don't know about CoW forks, so don't
+ * be too surprised if it fails.
+ */
+ if (whichfork == XFS_COW_FORK && error && errno == EINVAL)
+ error = 0;
+
+ if (error)
+ str_errno(ctx, bmap_descr);
+out:
+ free(map);
+ return moveon;
+}
diff --git a/scrub/filemap.h b/scrub/filemap.h
new file mode 100644
index 0000000..30d53d0
--- /dev/null
+++ b/scrub/filemap.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2018 Oracle. All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+#ifndef XFS_SCRUB_FILEMAP_H_
+#define XFS_SCRUB_FILEMAP_H_
+
+/* inode fork block mapping */
+struct xfs_bmap {
+ uint64_t bm_offset; /* file offset of segment in bytes */
+ uint64_t bm_physical; /* physical starting byte */
+ uint64_t bm_length; /* length of segment, bytes */
+ uint32_t bm_flags; /* output flags */
+};
+
+typedef bool (*xfs_bmap_iter_fn)(struct scrub_ctx *ctx, const char *descr,
+ int fd, int whichfork, struct fsxattr *fsx,
+ struct xfs_bmap *bmap, void *arg);
+
+bool xfs_iterate_filemaps(struct scrub_ctx *ctx, const char *descr, int fd,
+ int whichfork, struct xfs_bmap *key, xfs_bmap_iter_fn fn,
+ void *arg);
+
+#endif /* XFS_SCRUB_FILEMAP_H_ */
--
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