First, add a generic scrubber implementation that uses standard VFS
interfaces to walk as much of a filesystem's metadata as possible. We
can use this to scrub non-XFS filesystems, though the primary intent is
to provide a fallback for the XFS driver should some features be
unavailable.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
scrub/Makefile | 2
scrub/generic.c | 1152 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
scrub/scrub.c | 2
scrub/scrub.h | 2
4 files changed, 1156 insertions(+), 2 deletions(-)
create mode 100644 scrub/generic.c
diff --git a/scrub/Makefile b/scrub/Makefile
index 2aa359b..4639eed 100644
--- a/scrub/Makefile
+++ b/scrub/Makefile
@@ -13,7 +13,7 @@ INSTALL_SCRUB = install-scrub
endif
HFILES = scrub.h ../repair/threads.h read_verify.h iocmd.h
-CFILES = ../repair/avl64.c disk.c bitmap.c iocmd.c \
+CFILES = ../repair/avl64.c disk.c bitmap.c generic.c iocmd.c \
read_verify.c scrub.c ../repair/threads.c
LLDLIBS += $(LIBBLKID) $(LIBXFS) $(LIBXCMD) $(LIBUUID) $(LIBRT) $(LIBPTHREAD) $(LIBHANDLE)
diff --git a/scrub/generic.c b/scrub/generic.c
new file mode 100644
index 0000000..dbde103
--- /dev/null
+++ b/scrub/generic.c
@@ -0,0 +1,1152 @@
+/*
+ * Copyright (C) 2017 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 "libxfs.h"
+#include <linux/fiemap.h>
+#include <sys/statvfs.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <sys/xattr.h>
+#include "disk.h"
+#include "scrub.h"
+#include "iocmd.h"
+#include "../repair/threads.h"
+#include "read_verify.h"
+#include "bitmap.h"
+
+/*
+ * Generic Filesystem Scrub Strategy
+ *
+ * For a generic filesystem, we can only scrub the filesystem using the
+ * generic VFS APIs that are accessible to userspace. This requirement
+ * reduces the effectiveness of the scrub because we can only scrub that
+ * which we can find through the directory tree namespace -- we won't be
+ * able to examine open unlinked files or any directory subtree that is
+ * also a mountpoint.
+ *
+ * The "find geometry" phase collects statfs/statvfs information and
+ * opens file descriptors to the mountpoint. If the filesystem has a
+ * block device, a file descriptor is opened to that as well.
+ *
+ * The VFS has no mechanism to scrub internal metadata or to iterate
+ * inodes by inode number, so those phases do nothing.
+ *
+ * The "check directory structure" phase walks the directory tree
+ * looking for inodes. Each directory is processed separately by thread
+ * pool workers. For each entry in a directory, we scrub the following
+ * pieces of metadata:
+ *
+ * - The dirent inode number is compared against the fstatat output.
+ * - The dirent type code is also checked against the fstatat type.
+ * - If it's a symlink, the target is read but not validated.
+ * - If the entry is not a file or directory, the extended
+ * attributes names and values are read via llistxattr.
+ * - If the entry points to a file or directory, open the inode.
+ * If not, we're done with the entry.
+ * - The inode stat buffer is re-checked.
+ * - The extent maps for file data and extended attribute data are
+ * checked.
+ * - Extended attributes are read.
+ *
+ * The "verify data file integrity" phase re-walks the directory tree
+ * for files. If the filesystem supports FIEMAP and we have the block
+ * device open, the data extents are read directly from disk. This step
+ * is optimized by buffering the disk extents in a bitmap and using the
+ * bitmap to issue large IOs; if there are errors, those are recorded
+ * and cross-referenced against the metadata to identify the affected
+ * files with a second walk/FIEMAP run. If FIEMAP is unavailable, it
+ * falls back to using SEEK_DATA and SEEK_HOLE to direct-read file
+ * contents. If even that fails, direct-read the entire file.
+ *
+ * In the "check summary counters" phase, we tally up the blocks and
+ * inodes we saw and compare that to the statfs output. This gives the
+ * user a rough estimate of how thorough the scrub was.
+ */
+
+#ifndef SEEK_DATA
+# define SEEK_DATA 3 /* seek to the next data */
+#endif
+
+#ifndef SEEK_HOLE
+# define SEEK_HOLE 4 /* seek to the next hole */
+#endif
+
+/* Routines to translate bad physical extents into file paths and offsets. */
+
+/* Report if this extent overlaps a bad region. */
+static bool
+report_verify_inode_fiemap(
+ struct scrub_ctx *ctx,
+ const char *descr,
+ struct fiemap_extent *extent,
+ void *arg)
+{
+ struct bitmap *tree = arg;
+
+ /* Skip non-real/non-aligned extents. */
+ if (extent->fe_flags & (FIEMAP_EXTENT_UNKNOWN |
+ FIEMAP_EXTENT_DELALLOC |
+ FIEMAP_EXTENT_ENCODED |
+ FIEMAP_EXTENT_NOT_ALIGNED |
+ FIEMAP_EXTENT_UNWRITTEN))
+ return true;
+
+ if (!bitmap_has_extent(tree, extent->fe_physical,
+ extent->fe_length))
+ return true;
+
+ str_error(ctx, descr,
+_("offset %llu failed read verification."), extent->fe_logical);
+
+ return true;
+}
+
+/* Iterate the extent mappings of a file to report errors. */
+static bool
+report_verify_fd(
+ struct scrub_ctx *ctx,
+ const char *descr,
+ int fd,
+ void *arg)
+{
+ /* data fork */
+ fiemap(ctx, descr, fd, false, false, report_verify_inode_fiemap, arg);
+
+ /* attr fork */
+ fiemap(ctx, descr, fd, true, false, report_verify_inode_fiemap, arg);
+
+ return true;
+}
+
+/* Scan the inode associated with a directory entry. */
+static bool
+report_verify_dirent(
+ struct scrub_ctx *ctx,
+ const char *path,
+ int dir_fd,
+ struct dirent *dirent,
+ struct stat *sb,
+ void *arg)
+{
+ bool moveon;
+ int fd;
+
+ /* Ignore things we can't open. */
+ if (!S_ISREG(sb->st_mode))
+ return true;
+ /* Ignore . and .. */
+ if (dirent && (!strcmp(".", dirent->d_name) ||
+ !strcmp("..", dirent->d_name)))
+ return true;
+
+ /* Open the file */
+ fd = dirent_open(dir_fd, dirent);
+ if (fd < 0)
+ return true;
+
+ /* Go find the badness. */
+ moveon = report_verify_fd(ctx, path, fd, arg);
+ if (moveon)
+ goto out;
+
+out:
+ close(fd);
+
+ return moveon;
+}
+
+/* Given bad extent lists for the data device, find bad files. */
+static bool
+report_verify_errors(
+ struct scrub_ctx *ctx,
+ struct bitmap *d_bad)
+{
+ /* Scan the directory tree to get file paths. */
+ return scan_fs_tree(ctx, NULL, report_verify_dirent, d_bad);
+}
+
+/* Phase 1 */
+bool
+generic_scan_fs(
+ struct scrub_ctx *ctx)
+{
+ /* If there's no disk device, forget FIEMAP. */
+ if (!disk_is_open(&ctx->datadev))
+ ctx->quirks &= ~(SCRUB_QUIRK_FIEMAP_WORKS |
+ SCRUB_QUIRK_FIEMAP_ATTR_WORKS |
+ SCRUB_QUIRK_FIBMAP_WORKS);
+
+ return true;
+}
+
+bool
+generic_cleanup(
+ struct scrub_ctx *ctx)
+{
+ /* Nothing to do here. */
+ return true;
+}
+
+/* Phase 2 */
+bool
+generic_scan_metadata(
+ struct scrub_ctx *ctx)
+{
+ /* Nothing to do here. */
+ return true;
+}
+
+/* Phase 3 */
+bool
+generic_scan_inodes(
+ struct scrub_ctx *ctx)
+{
+ /* Nothing to do here. */
+ return true;
+}
+
+/* Phase 4 */
+
+/* Check all entries in a directory. */
+bool
+generic_check_dir(
+ struct scrub_ctx *ctx,
+ const char *descr,
+ int dir_fd)
+{
+ /* Nothing to do here. */
+ return true;
+}
+
+/* Check an extent for problems. */
+static bool
+check_fiemap_extent(
+ struct scrub_ctx *ctx,
+ const char *descr,
+ struct fiemap_extent *extent,
+ void *arg)
+{
+ unsigned long long eofs;
+
+ if (!disk_is_open(&ctx->datadev))
+ return true;
+ eofs = ctx->datadev.d_size;
+
+ if (extent->fe_length == 0)
+ str_error(ctx, descr,
+_("extent (%llu/%llu/%llu) has zero length."),
+ extent->fe_physical,
+ extent->fe_logical,
+ extent->fe_length);
+ if (extent->fe_physical > eofs)
+ str_error(ctx, descr,
+_("extent (%llu/%llu/%llu) starts past end of filesystem at %llu."),
+ extent->fe_physical,
+ extent->fe_logical,
+ extent->fe_length,
+ eofs);
+ if (extent->fe_physical + extent->fe_length > eofs ||
+ extent->fe_physical + extent->fe_length < extent->fe_physical)
+ str_error(ctx, descr,
+_("extent (%llu/%llu/%llu) ends past end of filesystem at %llu."),
+ extent->fe_physical,
+ extent->fe_logical,
+ extent->fe_length,
+ eofs);
+ if (extent->fe_logical + extent->fe_length < extent->fe_logical)
+ str_error(ctx, descr,
+_("extent (%llu/%llu/%llu) overflows file offset."),
+ extent->fe_physical,
+ extent->fe_logical,
+ extent->fe_length);
+ return true;
+}
+
+/* Check an inode's extents. */
+bool
+generic_scan_extents(
+ struct scrub_ctx *ctx,
+ const char *descr,
+ int fd,
+ struct stat *sb,
+ bool attr_fork)
+{
+ /* FIEMAP only works for files. */
+ if (!S_ISREG(sb->st_mode))
+ return true;
+
+ /* Don't invoke FIEMAP if we don't support it. */
+ if (attr_fork && !scrub_has_fiemap_attr(ctx))
+ return true;
+ if (!attr_fork && !(scrub_has_fiemap(ctx) || scrub_has_fibmap(ctx)))
+ return true;
+
+ return fiemap(ctx, descr, fd, attr_fork, true,
+ check_fiemap_extent, NULL);
+}
+
+/* Check the fields of an inode. */
+bool
+generic_check_inode(
+ struct scrub_ctx *ctx,
+ const char *descr,
+ int fd,
+ struct stat *sb)
+{
+ if (sb->st_nlink == 0)
+ str_error(ctx, descr,
+_("nlinks should not be 0."));
+
+ return true;
+}
+
+/* Does this file have extended attributes? */
+bool
+file_has_xattrs(
+ struct scrub_ctx *ctx,
+ const char *descr,
+ int fd)
+{
+ ssize_t buf_sz;
+
+ buf_sz = flistxattr(fd, NULL, 0);
+ if (buf_sz == 0)
+ return false;
+ else if (buf_sz < 0) {
+ if (errno == EOPNOTSUPP || errno == ENODATA)
+ return false;
+ str_errno(ctx, descr);
+ return false;
+ }
+
+ return true;
+}
+
+/* Try to read all the extended attributes. */
+bool
+generic_scan_xattrs(
+ struct scrub_ctx *ctx,
+ const char *descr,
+ int fd)
+{
+ char *buf = NULL;
+ char *p;
+ ssize_t buf_sz;
+ ssize_t sz;
+ ssize_t val_sz;
+ ssize_t sz2;
+ bool moveon = true;
+
+ buf_sz = flistxattr(fd, NULL, 0);
+ if (buf_sz == 0)
+ return true;
+ else if (buf_sz < 0) {
+ if (errno == EOPNOTSUPP || errno == ENODATA)
+ return true;
+ str_errno(ctx, descr);
+ return true;
+ }
+
+ buf = malloc(buf_sz);
+ if (!buf) {
+ str_errno(ctx, descr);
+ return false;
+ }
+
+ sz = flistxattr(fd, buf, buf_sz);
+ if (sz < 0) {
+ str_errno(ctx, descr);
+ goto out;
+ } else if (sz != buf_sz) {
+ str_error(ctx, descr,
+_("read %zu bytes of xattr names, expected %zu bytes."),
+ sz, buf_sz);
+ }
+
+ /* Read all the attrs and values. */
+ for (p = buf; p < buf + sz; p += strlen(p) + 1) {
+ val_sz = fgetxattr(fd, p, NULL, 0);
+ if (val_sz < 0) {
+ if (errno != EOPNOTSUPP && errno != ENODATA)
+ str_errno(ctx, descr);
+ continue;
+ }
+ sz2 = fgetxattr(fd, p, ctx->readbuf, val_sz);
+ if (sz2 < 0) {
+ str_errno(ctx, descr);
+ continue;
+ } else if (sz2 != val_sz)
+ str_error(ctx, descr,
+_("read %zu bytes from xattr %s value, expected %zu bytes."),
+ sz2, p, val_sz);
+ }
+out:
+ free(buf);
+ return moveon;
+}
+
+/* Try to read all the extended attributes of things that have no fd. */
+bool
+generic_scan_special_xattrs(
+ struct scrub_ctx *ctx,
+ const char *path)
+{
+ char *buf = NULL;
+ char *p;
+ ssize_t buf_sz;
+ ssize_t sz;
+ ssize_t val_sz;
+ ssize_t sz2;
+ bool moveon = true;
+
+ buf_sz = llistxattr(path, NULL, 0);
+ if (buf_sz == -EOPNOTSUPP)
+ return true;
+ else if (buf_sz == 0)
+ return true;
+ else if (buf_sz < 0) {
+ str_errno(ctx, path);
+ return true;
+ }
+
+ buf = malloc(buf_sz);
+ if (!buf) {
+ str_errno(ctx, path);
+ return false;
+ }
+
+ sz = llistxattr(path, buf, buf_sz);
+ if (sz < 0) {
+ str_errno(ctx, path);
+ goto out;
+ } else if (sz != buf_sz) {
+ str_error(ctx, path,
+_("read %zu bytes of xattr names, expected %zu bytes."),
+ sz, buf_sz);
+ }
+
+ /* Read all the attrs and values. */
+ for (p = buf; p < buf + sz; p += strlen(p) + 1) {
+ val_sz = lgetxattr(path, p, NULL, 0);
+ if (val_sz < 0) {
+ str_errno(ctx, path);
+ continue;
+ }
+ sz2 = lgetxattr(path, p, ctx->readbuf, val_sz);
+ if (sz2 < 0) {
+ str_errno(ctx, path);
+ continue;
+ } else if (sz2 != val_sz)
+ str_error(ctx, path,
+_("read %zu bytes from xattr %s value, expected %zu bytes."),
+ sz2, p, val_sz);
+
+ if (xfs_scrub_excessive_errors(ctx)) {
+ moveon = false;
+ break;
+ }
+ }
+out:
+ free(buf);
+ return moveon;
+}
+
+/* Directory checking */
+#define CHECK_TYPE(type) \
+ case DT_##type: \
+ if (!S_IS##type(sb->st_mode)) { \
+ str_error(ctx, descr, \
+_("dtype of block does not match mode 0x%x\n"), \
+ sb->st_mode & S_IFMT); \
+ } \
+ break;
+
+/* Ensure that the directory entry matches the stat info. */
+static bool
+generic_verify_dirent(
+ struct scrub_ctx *ctx,
+ const char *descr,
+ struct dirent *dirent,
+ struct stat *sb)
+{
+ if (!scrub_has_unstable_inums(ctx) && dirent->d_ino != sb->st_ino) {
+ str_error(ctx, descr,
+_("inode numbers (%llu != %llu) do not match!"),
+ (unsigned long long)dirent->d_ino,
+ (unsigned long long)sb->st_ino);
+ }
+
+ switch (dirent->d_type) {
+ case DT_UNKNOWN:
+ break;
+ CHECK_TYPE(BLK)
+ CHECK_TYPE(CHR)
+ CHECK_TYPE(DIR)
+ CHECK_TYPE(FIFO)
+ CHECK_TYPE(LNK)
+ CHECK_TYPE(REG)
+ CHECK_TYPE(SOCK)
+ }
+
+ return true;
+}
+#undef CHECK_TYPE
+
+/* Scan the inode associated with a directory entry. */
+static bool
+check_dirent(
+ struct scrub_ctx *ctx,
+ const char *path,
+ int dir_fd,
+ struct dirent *dirent,
+ struct stat *sb,
+ void *arg)
+{
+ struct stat fd_sb;
+ static char linkbuf[PATH_MAX + 1];
+ ssize_t len;
+ bool moveon;
+ int fd;
+ int error;
+
+ /* No dirent for the rootdir; skip it. */
+ if (!dirent)
+ return true;
+
+ /* Check the directory entry itself. */
+ moveon = generic_verify_dirent(ctx, path, dirent, sb);
+ if (!moveon)
+ return moveon;
+
+ /* If symlink, read the target value. */
+ if (S_ISLNK(sb->st_mode)) {
+ len = readlinkat(dir_fd, dirent->d_name, linkbuf,
+ PATH_MAX);
+ if (len < 0)
+ str_errno(ctx, path);
+ else if (len > sb->st_size)
+ str_error(ctx, path,
+_("read %zu bytes from a %zu byte symlink?"),
+ len, sb->st_size);
+ }
+
+ /* Read the xattrs without a file descriptor. */
+ if (S_ISSOCK(sb->st_mode) || S_ISFIFO(sb->st_mode) ||
+ S_ISBLK(sb->st_mode) || S_ISCHR(sb->st_mode) ||
+ S_ISLNK(sb->st_mode)) {
+ moveon = ctx->ops->scan_special_xattrs(ctx, path);
+ if (!moveon)
+ return moveon;
+ }
+
+ /* If not dir or file, move on to the next dirent. */
+ if (!S_ISDIR(sb->st_mode) && !S_ISREG(sb->st_mode))
+ return true;
+
+ /* Open the file */
+ fd = openat(dir_fd, dirent->d_name,
+ O_RDONLY | O_NOATIME | O_NOFOLLOW | O_NOCTTY);
+ if (fd < 0) {
+ if (errno != ENOENT)
+ str_errno(ctx, path);
+ return true;
+ }
+
+ /* Did the fstatat and the open race? */
+ if (fstat(fd, &fd_sb) < 0) {
+ str_errno(ctx, path);
+ goto close;
+ }
+ if (fd_sb.st_ino != sb->st_ino || fd_sb.st_dev != sb->st_dev)
+ str_warn(ctx, path,
+_("inode changed out from under us!"));
+
+ /* Check the inode. */
+ moveon = ctx->ops->check_inode(ctx, path, fd, &fd_sb);
+ if (!moveon)
+ goto close;
+
+ /* Scan the extent maps. */
+ moveon = ctx->ops->scan_extents(ctx, path, fd, &fd_sb, false);
+ if (!moveon)
+ goto close;
+ if (file_has_xattrs(ctx, path, fd)) {
+ moveon = ctx->ops->scan_extents(ctx, path, fd, &fd_sb, true);
+ if (!moveon)
+ goto close;
+ }
+
+ /* Read all the extended attributes. */
+ moveon = ctx->ops->scan_xattrs(ctx, path, fd);
+ if (!moveon)
+ goto close;
+
+close:
+ /* Close file. */
+ error = close(fd);
+ if (error)
+ str_errno(ctx, path);
+
+ return moveon;
+}
+
+/*
+ * Check all the entries in a directory.
+ */
+bool
+generic_check_directory(
+ struct scrub_ctx *ctx,
+ const char *descr,
+ int *pfd)
+{
+ struct stat sb;
+ DIR *dir;
+ struct dirent *dirent;
+ bool moveon = true;
+ int fd = *pfd;
+ int error;
+
+ /* Iterate the directory entries. */
+ dir = fdopendir(fd);
+ if (!dir) {
+ str_errno(ctx, descr);
+ return true;
+ }
+ rewinddir(dir);
+
+ /* Iterate every directory entry. */
+ for (dirent = readdir(dir);
+ dirent != NULL;
+ dirent = readdir(dir)) {
+ error = fstatat(fd, dirent->d_name, &sb,
+ AT_NO_AUTOMOUNT | AT_SYMLINK_NOFOLLOW);
+ if (error) {
+ str_errno(ctx, descr);
+ break;
+ }
+
+ /* Ignore files on other filesystems. */
+ if (sb.st_dev != ctx->mnt_sb.st_dev)
+ continue;
+
+ /* Check the type codes. */
+ moveon = generic_verify_dirent(ctx, descr, dirent, &sb);
+ if (!moveon)
+ break;
+
+ if (xfs_scrub_excessive_errors(ctx)) {
+ moveon = false;
+ break;
+ }
+ }
+
+ /* Close dir, go away. */
+ error = closedir(dir);
+ if (error)
+ str_errno(ctx, descr);
+ *pfd = -1;
+ return moveon;
+}
+
+/* Adapter for the check_dir thing. */
+static bool
+check_dir(
+ struct scrub_ctx *ctx,
+ const char *descr,
+ int dir_fd,
+ void *arg)
+{
+ return ctx->ops->check_dir(ctx, descr, dir_fd);
+}
+
+/* Traverse the directory tree. */
+bool
+generic_scan_fs_tree(
+ struct scrub_ctx *ctx)
+{
+ return scan_fs_tree(ctx, check_dir, check_dirent, NULL);
+}
+
+/* Phase 5 */
+
+struct read_verify_files {
+ struct scrub_ctx *ctx;
+ struct bitmap good; /* bytes */
+ struct bitmap bad; /* bytes */
+ struct read_verify_pool rvp;
+ struct read_verify rv;
+ bool use_fiemap;
+};
+
+/* Handle an io error while read verifying an extent. */
+void
+read_verify_fiemap_ioerr(
+ struct read_verify_pool *rvp,
+ struct disk *disk,
+ uint64_t start,
+ uint64_t length,
+ int error,
+ void *arg)
+{
+ struct read_verify_files *rvf = arg;
+
+ bitmap_add(&rvf->bad, start, length);
+}
+
+/* Check an extent for data integrity problems. */
+bool
+read_verify_fiemap_extent(
+ struct scrub_ctx *ctx,
+ const char *descr,
+ struct fiemap_extent *extent,
+ void *arg)
+{
+ struct read_verify_files *rvf = arg;
+
+ /* Skip non-real/non-aligned extents. */
+ if (extent->fe_flags & (FIEMAP_EXTENT_UNKNOWN |
+ FIEMAP_EXTENT_DELALLOC |
+ FIEMAP_EXTENT_ENCODED |
+ FIEMAP_EXTENT_NOT_ALIGNED |
+ FIEMAP_EXTENT_UNWRITTEN))
+ return true;
+
+ return bitmap_add(&rvf->good, extent->fe_physical,
+ extent->fe_length);
+}
+
+/* Scan the inode associated with a directory entry. */
+static bool
+read_verify_dirent(
+ struct scrub_ctx *ctx,
+ const char *path,
+ int dir_fd,
+ struct dirent *dirent,
+ struct stat *sb,
+ void *arg)
+{
+ struct stat fd_sb;
+ struct read_verify_files *rvf = arg;
+ bool moveon = true;
+ int fd;
+ int error;
+
+ /* If not file, move on to the next dirent. */
+ if (!S_ISREG(sb->st_mode))
+ return true;
+
+ /* Open the file */
+ fd = openat(dir_fd, dirent->d_name,
+ O_RDONLY | O_NOATIME | O_NOFOLLOW | O_NOCTTY);
+ if (fd < 0) {
+ if (errno != ENOENT)
+ str_errno(ctx, path);
+ return true;
+ }
+
+ /* Did the fstatat and the open race? */
+ if (fstat(fd, &fd_sb) < 0) {
+ str_errno(ctx, path);
+ goto close;
+ }
+ if (fd_sb.st_ino != sb->st_ino || fd_sb.st_dev != sb->st_dev)
+ str_warn(ctx, path,
+_("inode changed out from under us!"));
+
+ /*
+ * Either record the file extent map data for one big push later,
+ * or read the file data the regular way.
+ */
+ if (rvf->use_fiemap)
+ moveon = fiemap(ctx, path, fd, false, false,
+ read_verify_fiemap_extent, rvf);
+ else
+ moveon = ctx->ops->read_file(ctx, path, fd, &fd_sb);
+ if (!moveon)
+ goto close;
+
+close:
+ /* Close file. */
+ error = close(fd);
+ if (error)
+ str_errno(ctx, path);
+
+ return moveon;
+}
+
+static bool
+schedule_read_verify(
+ uint64_t start,
+ uint64_t length,
+ void *arg)
+{
+ struct read_verify_files *rvf = arg;
+
+ read_verify_schedule(&rvf->rvp, &rvf->rv, &rvf->ctx->datadev,
+ start, length, rvf);
+ return true;
+}
+
+/* Can we FIEMAP every block in a file? */
+static bool
+can_fiemap_all_file_blocks(
+ struct scrub_ctx *ctx)
+{
+ return disk_is_open(&ctx->datadev) &&
+ scrub_has_fiemap(ctx) && scrub_has_fiemap_attr(ctx);
+}
+
+/* Scan all the data blocks, using FIEMAP to figure out what to verify. */
+bool
+generic_scan_blocks(
+ struct scrub_ctx *ctx)
+{
+ struct read_verify_files rvf = {0};
+ bool moveon;
+
+ if (!scrub_data)
+ return true;
+
+ rvf.ctx = ctx;
+
+ /* If FIEMAP is unavailable, just use regular file pread. */
+ if (!can_fiemap_all_file_blocks(ctx))
+ return scan_fs_tree(ctx, NULL, read_verify_dirent, &rvf);
+
+ rvf.use_fiemap = true;
+ moveon = bitmap_init(&rvf.good);
+ if (!moveon) {
+ str_errno(ctx, ctx->mntpoint);
+ return false;
+ }
+
+ moveon = bitmap_init(&rvf.bad);
+ if (!moveon) {
+ str_errno(ctx, ctx->mntpoint);
+ goto out_good;
+ }
+
+ /* Collect all the extent maps. */
+ moveon = scan_fs_tree(ctx, NULL, read_verify_dirent, &rvf);
+ if (!moveon)
+ goto out_bad;
+
+ /* Run all the IO in batches. */
+ moveon = read_verify_pool_init(&rvf.rvp, ctx, ctx->readbuf, IO_MAX_SIZE,
+ ctx->mnt_sf.f_frsize, read_verify_fiemap_ioerr,
+ disk_heads(&ctx->datadev));
+ if (!moveon)
+ goto out_bad;
+ moveon = bitmap_iterate(&rvf.good, schedule_read_verify, &rvf);
+ if (!moveon)
+ goto out_pool;
+ read_verify_force(&rvf.rvp, &rvf.rv);
+ read_verify_pool_destroy(&rvf.rvp);
+
+ /* Scan the whole dir tree to see what matches the bad extents. */
+ if (!bitmap_empty(&rvf.bad))
+ moveon = report_verify_errors(ctx, &rvf.bad);
+
+ bitmap_free(&rvf.bad);
+ bitmap_free(&rvf.good);
+ return moveon;
+
+out_pool:
+ read_verify_pool_destroy(&rvf.rvp);
+out_bad:
+ bitmap_free(&rvf.bad);
+out_good:
+ bitmap_free(&rvf.good);
+
+ return moveon;
+}
+
+/* Phase 6 */
+struct summary_counts {
+ pthread_mutex_t lock;
+ struct bitmap dext;
+ struct bitmap inob; /* inode bitmap */
+ unsigned long long inodes; /* number of inodes */
+ unsigned long long bytes; /* bytes used */
+};
+
+struct inode_fork_summary {
+ struct bitmap *tree;
+ unsigned long long bytes;
+};
+
+/* Record data block extents in a bitmap. */
+bool
+generic_record_inode_summary_fiemap(
+ struct scrub_ctx *ctx,
+ const char *descr,
+ struct fiemap_extent *extent,
+ void *arg)
+{
+ struct inode_fork_summary *ifs = arg;
+
+ /* Skip non-real/non-aligned extents. */
+ if (extent->fe_flags & (FIEMAP_EXTENT_UNKNOWN |
+ FIEMAP_EXTENT_DELALLOC |
+ FIEMAP_EXTENT_ENCODED |
+ FIEMAP_EXTENT_NOT_ALIGNED))
+ return true;
+
+ bitmap_add(ifs->tree, extent->fe_physical, extent->fe_length);
+ ifs->bytes += extent->fe_length;
+
+ return true;
+}
+
+/* Record the presence of an inode and its block usage. */
+static bool
+generic_record_inode_summary(
+ struct scrub_ctx *ctx,
+ const char *descr,
+ int dir_fd,
+ struct dirent *dirent,
+ struct stat *sb,
+ void *arg)
+{
+ struct summary_counts *summary = arg;
+ struct stat fd_sb;
+ struct inode_fork_summary ifs;
+ unsigned long long bs_bytes;
+ int fd;
+ bool has;
+ bool moveon = true;
+
+ if (dirent && (strcmp(dirent->d_name, ".") == 0 ||
+ strcmp(dirent->d_name, "..") == 0))
+ return true;
+
+ /* Detect hardlinked files. */
+ moveon = bitmap_test_and_set(&summary->inob, sb->st_ino, &has);
+ if (!moveon)
+ return moveon;
+ if (has)
+ return true;
+
+ bs_bytes = sb->st_blocks << BBSHIFT;
+
+ /* Record the inode. If it's not a file, record the data usage too. */
+ pthread_mutex_lock(&summary->lock);
+ summary->inodes++;
+
+ /*
+ * We can use fiemap and dext to figure out the correct block usage
+ * for files that might share blocks. If any of those conditions
+ * are not met (non-file, fs doesn't support reflink, fiemap doesn't
+ * work) then we just assume that the inode is the sole owner of its
+ * blocks and use that to calculate the block usage.
+ */
+ if (!can_fiemap_all_file_blocks(ctx) || !scrub_has_shared_blocks(ctx) ||
+ !S_ISREG(sb->st_mode)) {
+ summary->bytes += bs_bytes;
+ pthread_mutex_unlock(&summary->lock);
+ return true;
+ }
+ pthread_mutex_unlock(&summary->lock);
+
+ /* Open the file */
+ fd = dirent_open(dir_fd, dirent);
+ if (fd < 0) {
+ if (errno != ENOENT)
+ str_errno(ctx, descr);
+ return true;
+ }
+
+ /* Did the fstatat and the open race? */
+ if (fstat(fd, &fd_sb) < 0) {
+ str_errno(ctx, descr);
+ goto close;
+ }
+
+ if (fd_sb.st_ino != sb->st_ino || fd_sb.st_dev != sb->st_dev)
+ str_warn(ctx, descr,
+_("inode changed out from under us!"));
+
+ ifs.tree = &summary->dext;
+ ifs.bytes = 0;
+ moveon = fiemap(ctx, descr, fd, false, false,
+ generic_record_inode_summary_fiemap, &ifs);
+ if (!moveon)
+ goto out_nofiemap;
+ if (file_has_xattrs(ctx, descr, fd)) {
+ moveon = fiemap(ctx, descr, fd, true, false,
+ generic_record_inode_summary_fiemap, &ifs);
+ if (!moveon)
+ goto out_nofiemap;
+ }
+
+ /*
+ * bs_bytes tracks the number of bytes assigned to this file
+ * for data, xattrs, and block mapping metadata. ifs.bytes tracks
+ * the data and xattr storage space used, so the diff between the
+ * two is the space used for block mapping metadata. Add that to
+ * the data usage.
+ */
+out_nofiemap:
+ pthread_mutex_lock(&summary->lock);
+ summary->bytes += bs_bytes - ifs.bytes;
+ pthread_mutex_unlock(&summary->lock);
+
+close:
+ close(fd);
+ return moveon;
+}
+
+/* Sum the bytes in each extent. */
+static bool
+generic_summary_count_helper(
+ uint64_t start,
+ uint64_t length,
+ void *arg)
+{
+ unsigned long long *count = arg;
+
+ *count += length;
+ return true;
+}
+
+/* Traverse the directory tree, counting inodes & blocks. */
+bool
+generic_check_summary(
+ struct scrub_ctx *ctx)
+{
+ struct summary_counts summary = {0};
+ struct stat sb;
+ struct statvfs sfs;
+ unsigned long long fd;
+ unsigned long long fi;
+ unsigned long long sd;
+ unsigned long long si;
+ unsigned long long absdiff;
+ bool complain = false;
+ bool moveon;
+ int error;
+
+ pthread_mutex_init(&summary.lock, NULL);
+
+ /* Flush everything out to disk before we start counting. */
+ error = syncfs(ctx->mnt_fd);
+ if (error) {
+ str_errno(ctx, ctx->mntpoint);
+ return false;
+ }
+
+ /* Get the rootdir's summary stats. */
+ error = fstat(ctx->mnt_fd, &sb);
+ if (error) {
+ str_errno(ctx, ctx->mntpoint);
+ return false;
+ }
+
+ moveon = bitmap_init(&summary.dext);
+ if (!moveon)
+ return moveon;
+
+ moveon = bitmap_init(&summary.inob);
+ if (!moveon)
+ return moveon;
+
+ /* Scan the rest of the filesystem. */
+ moveon = scan_fs_tree(ctx, NULL, generic_record_inode_summary,
+ &summary);
+ if (!moveon)
+ return moveon;
+
+ /* Summarize extent tree results. */
+ moveon = bitmap_iterate(&summary.dext,
+ generic_summary_count_helper, &summary.bytes);
+ if (!moveon)
+ return moveon;
+
+ bitmap_free(&summary.inob);
+ bitmap_free(&summary.dext);
+
+ /* Compare to statfs results. */
+ error = fstatvfs(ctx->mnt_fd, &sfs);
+ if (error) {
+ str_errno(ctx, ctx->mntpoint);
+ return false;
+ }
+
+ /* Report on what we found. */
+ fd = (sfs.f_blocks - sfs.f_bfree) * sfs.f_frsize;
+ fi = sfs.f_files - sfs.f_ffree;
+ sd = summary.bytes;
+ si = summary.inodes;
+
+ /*
+ * Complain if the counts are off by more than 10%, unless
+ * the inaccuracy is less than 32MB worth of blocks or 100 inodes.
+ * Ignore zero counters.
+ */
+ absdiff = 1ULL << 25;
+ if (fd)
+ complain = !within_range(ctx, sd, fd, absdiff, 1, 10,
+ _("data blocks"));
+ if (fi)
+ complain |= !within_range(ctx, si, fi, 100, 1, 10, _("inodes"));
+
+ if (complain || verbose) {
+ double b, i;
+ char *bu, *iu;
+
+ b = auto_space_units(fd, &bu);
+ i = auto_units(fi, &iu);
+ fprintf(stdout, _("%.1f%s data used; %.1f%s inodes used.\n"),
+ b, bu, i, iu);
+ b = auto_space_units(sd, &bu);
+ i = auto_units(si, &iu);
+ fprintf(stdout, _("%.1f%s data found; %.1f%s inodes found.\n"),
+ b, bu, i, iu);
+ fflush(stdout);
+ }
+
+ return true;
+}
+
+/* Phase 7: Preening filesystem. */
+bool
+generic_preen_fs(
+ struct scrub_ctx *ctx)
+{
+ fstrim(ctx);
+ return true;
+}
+
+struct scrub_ops generic_scrub_ops = {
+ .name = "generic",
+ .cleanup = generic_cleanup,
+ .scan_fs = generic_scan_fs,
+ .scan_inodes = generic_scan_inodes,
+ .check_dir = generic_check_dir,
+ .check_inode = generic_check_inode,
+ .scan_extents = generic_scan_extents,
+ .scan_xattrs = generic_scan_xattrs,
+ .scan_special_xattrs = generic_scan_special_xattrs,
+ .scan_metadata = generic_scan_metadata,
+ .check_summary = generic_check_summary,
+ .read_file = read_verify_file,
+ .scan_blocks = generic_scan_blocks,
+ .scan_fs_tree = generic_scan_fs_tree,
+ .preen_fs = generic_preen_fs,
+};
diff --git a/scrub/scrub.c b/scrub/scrub.c
index 5ed6559..7ed5374 100644
--- a/scrub/scrub.c
+++ b/scrub/scrub.c
@@ -783,7 +783,7 @@ find_ops(
return op;
}
- return NULL;
+ return &generic_scrub_ops;
}
int
diff --git a/scrub/scrub.h b/scrub/scrub.h
index 442371b..6ab53c1 100644
--- a/scrub/scrub.h
+++ b/scrub/scrub.h
@@ -150,6 +150,8 @@ debug_tweak_on(
return debug && getenv(name) != NULL;
}
+extern struct scrub_ops generic_scrub_ops;
+
/* Generic implementations of the ops functions */
bool generic_cleanup(struct scrub_ctx *ctx);
bool generic_scan_fs(struct scrub_ctx *ctx);
--
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