From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Create an abstraction to handle all of our low level disk operations.
We'll eventually use it to bind to a fs mount point and block device.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
scrub/Makefile | 2 +
scrub/disk.c | 164 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
scrub/disk.h | 39 +++++++++++++
3 files changed, 205 insertions(+)
create mode 100644 scrub/disk.c
create mode 100644 scrub/disk.h
diff --git a/scrub/Makefile b/scrub/Makefile
index 097ec84..c3a9986 100644
--- a/scrub/Makefile
+++ b/scrub/Makefile
@@ -17,10 +17,12 @@ endif # scrub_prereqs
HFILES = \
common.h \
+disk.h \
xfs_scrub.h
CFILES = \
common.c \
+disk.c \
xfs_scrub.c
LLDLIBS += $(LIBHANDLE) $(LIBFROG) $(LIBPTHREAD)
diff --git a/scrub/disk.c b/scrub/disk.c
new file mode 100644
index 0000000..d4bf81f
--- /dev/null
+++ b/scrub/disk.c
@@ -0,0 +1,164 @@
+/*
+ * 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 <stdint.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/statvfs.h>
+#include <sys/vfs.h>
+#include <linux/fs.h>
+#include "platform_defs.h"
+#include "libfrog.h"
+#include "xfs_scrub.h"
+#include "disk.h"
+
+/*
+ * Disk Abstraction
+ *
+ * These routines help us to discover the geometry of a block device,
+ * estimate the amount of concurrent IOs that we can send to it, and
+ * abstract the process of performing read verification of disk blocks.
+ */
+
+/* Figure out how many disk heads are available. */
+static unsigned int
+__disk_heads(
+ struct disk *disk)
+{
+ int iomin;
+ int ioopt;
+ unsigned short rot;
+ int error;
+
+ /* If it's not a block device, throw all the CPUs at it. */
+ if (!S_ISBLK(disk->d_sb.st_mode))
+ return nproc;
+
+ /* Non-rotational device? Throw all the CPUs. */
+ rot = 1;
+ error = ioctl(disk->d_fd, BLKROTATIONAL, &rot);
+ if (error == 0 && rot == 0)
+ return nproc;
+
+ /*
+ * Sometimes we can infer the number of devices from the
+ * min/optimal IO sizes.
+ */
+ iomin = ioopt = 0;
+ if (ioctl(disk->d_fd, BLKIOMIN, &iomin) == 0 &&
+ ioctl(disk->d_fd, BLKIOOPT, &ioopt) == 0 &&
+ iomin > 0 && ioopt > 0) {
+ return min(nproc, max(1, ioopt / iomin));
+ }
+
+ /* Rotating device? I guess? */
+ return 2;
+}
+
+/* Figure out how many disk heads are available. */
+unsigned int
+disk_heads(
+ struct disk *disk)
+{
+ if (nr_threads)
+ return nr_threads;
+ return __disk_heads(disk);
+}
+
+/* Open a disk device and discover its geometry. */
+struct disk *
+disk_open(
+ const char *pathname)
+{
+ struct disk *disk;
+ int lba_sz;
+ int error;
+
+ disk = calloc(1, sizeof(struct disk));
+ if (!disk)
+ return NULL;
+
+ disk->d_fd = open(pathname, O_RDONLY | O_DIRECT | O_NOATIME);
+ if (disk->d_fd < 0)
+ goto out_free;
+
+ /* Try to get LBA size. */
+ error = ioctl(disk->d_fd, BLKSSZGET, &lba_sz);
+ if (error)
+ lba_sz = 512;
+ disk->d_lbalog = log2_roundup(lba_sz);
+
+ /* Obtain disk's stat info. */
+ error = fstat(disk->d_fd, &disk->d_sb);
+ if (error)
+ goto out_close;
+
+ /* Determine bdev size, block size, and offset. */
+ if (S_ISBLK(disk->d_sb.st_mode)) {
+ error = ioctl(disk->d_fd, BLKGETSIZE64, &disk->d_size);
+ if (error)
+ disk->d_size = 0;
+ error = ioctl(disk->d_fd, BLKBSZGET, &disk->d_blksize);
+ if (error)
+ disk->d_blksize = 0;
+ disk->d_start = 0;
+ } else {
+ disk->d_size = disk->d_sb.st_size;
+ disk->d_blksize = disk->d_sb.st_blksize;
+ disk->d_start = 0;
+ }
+
+ return disk;
+out_close:
+ close(disk->d_fd);
+out_free:
+ free(disk);
+ return NULL;
+}
+
+/* Close a disk device. */
+int
+disk_close(
+ struct disk *disk)
+{
+ int error = 0;
+
+ if (disk->d_fd >= 0)
+ error = close(disk->d_fd);
+ disk->d_fd = -1;
+ free(disk);
+ return error;
+}
+
+/* Read-verify an extent of a disk device. */
+ssize_t
+disk_read_verify(
+ struct disk *disk,
+ void *buf,
+ uint64_t start,
+ uint64_t length)
+{
+ return pread(disk->d_fd, buf, length, start);
+}
diff --git a/scrub/disk.h b/scrub/disk.h
new file mode 100644
index 0000000..834678e
--- /dev/null
+++ b/scrub/disk.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_DISK_H_
+#define XFS_SCRUB_DISK_H_
+
+struct disk {
+ struct stat d_sb;
+ int d_fd;
+ int d_lbalog;
+ unsigned int d_flags;
+ unsigned int d_blksize; /* bytes */
+ uint64_t d_size; /* bytes */
+ uint64_t d_start; /* bytes */
+};
+
+unsigned int disk_heads(struct disk *disk);
+struct disk *disk_open(const char *pathname);
+int disk_close(struct disk *disk);
+ssize_t disk_read_verify(struct disk *disk, void *buf, uint64_t startblock,
+ uint64_t blockcount);
+
+#endif /* XFS_SCRUB_DISK_H_ */
--
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