1 files changed, 341 insertions, 0 deletions
diff --git a/src/tools/cephfs/DataScan.h b/src/tools/cephfs/DataScan.h
new file mode 100644
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+++ b/src/tools/cephfs/DataScan.h
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+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2015 Red Hat
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation.  See file COPYING.
+ *
+ */
+
+
+#include "MDSUtility.h"
+#include "include/rados/librados.hpp"
+
+class InodeStore;
+class MDSTable;
+
+class RecoveryDriver {
+  protected:
+    // If true, overwrite structures that generate decoding errors.
+    bool force_corrupt;
+
+    // If true, overwrite root objects during init_roots even if they
+    // exist
+    bool force_init;
+
+  public:
+    virtual int init(
+        librados::Rados &rados,
+	std::string &metadata_pool_name,
+        const FSMap *fsmap,
+        fs_cluster_id_t fscid) = 0;
+
+    void set_force_corrupt(const bool val)
+    {
+      force_corrupt = val;
+    }
+
+    void set_force_init(const bool val)
+    {
+      force_init = val;
+    }
+
+
+    /**
+     * Inject an inode + dentry parents into the metadata pool,
+     * based on a backtrace recovered from the data pool
+     */
+    virtual int inject_with_backtrace(
+        const inode_backtrace_t &bt,
+        const InodeStore &dentry) = 0;
+
+    /**
+     * Inject an inode + dentry into the lost+found directory,
+     * when all we know about a file is its inode.
+     */
+    virtual int inject_lost_and_found(
+        inodeno_t ino,
+        const InodeStore &dentry) = 0;
+
+    /**
+     * Create any missing roots (i.e. mydir, strays, root inode)
+     */
+    virtual int init_roots(
+        int64_t data_pool_id) = 0;
+
+    /**
+     * Pre-injection check that all the roots are present in
+     * the metadata pool.  Used to avoid parallel workers interfering
+     * with one another, by cueing the user to go run 'init' on a
+     * single node before running a parallel scan.
+     *
+     * @param result: set to true if roots are present, else set to false
+     * @returns 0 on no unexpected errors, else error code.  Missing objects
+     *          are not considered an unexpected error: check *result for
+     *          this case.
+     */
+    virtual int check_roots(bool *result) = 0;
+
+    /**
+     * Helper to compose dnames for links to lost+found
+     * inodes.
+     */
+    std::string lost_found_dname(inodeno_t ino)
+    {
+      char s[20];
+      snprintf(s, sizeof(s), "%llx", (unsigned long long)ino);
+      return std::string(s);
+    }
+
+    RecoveryDriver()
+      : force_corrupt(false),
+	force_init(false)
+    {}
+
+    virtual ~RecoveryDriver() {}
+};
+
+class LocalFileDriver : public RecoveryDriver
+{ 
+  protected:
+    const std::string path;
+    librados::IoCtx &data_io;
+
+  int inject_data(
+      const std::string &file_path,
+      uint64_t size,
+      uint32_t chunk_size,
+      inodeno_t ino);
+  public:
+
+    LocalFileDriver(const std::string &path_, librados::IoCtx &data_io_)
+      : RecoveryDriver(), path(path_), data_io(data_io_)
+    {}
+
+    // Implement RecoveryDriver interface
+    int init(
+        librados::Rados &rados,
+	std::string &metadata_pool_name,
+        const FSMap *fsmap,
+        fs_cluster_id_t fscid) override;
+
+    int inject_with_backtrace(
+        const inode_backtrace_t &bt,
+        const InodeStore &dentry) override;
+
+    int inject_lost_and_found(
+        inodeno_t ino,
+        const InodeStore &dentry) override;
+
+    int init_roots(int64_t data_pool_id) override;
+
+    int check_roots(bool *result) override;
+};
+
+/**
+ * A class that knows how to work with objects in a CephFS
+ * metadata pool.
+ */
+class MetadataTool
+{
+  protected:
+
+  librados::IoCtx metadata_io;
+
+  /**
+   * Construct a synthetic InodeStore for a normal file
+   */
+  void build_file_dentry(
+    inodeno_t ino, uint64_t file_size, time_t file_mtime,
+    const file_layout_t &layout,
+    InodeStore *out);
+
+  /**
+   * Construct a synthetic InodeStore for a directory
+   */
+  void build_dir_dentry(
+    inodeno_t ino,
+    const frag_info_t &fragstat,
+    const file_layout_t &layout,
+    InodeStore *out);
+
+  /**
+   * Try and read an fnode from a dirfrag
+   */
+  int read_fnode(inodeno_t ino, frag_t frag,
+                 fnode_t *fnode, uint64_t *read_version);
+
+  /**
+   * Try and read a dentry from a dirfrag
+   */
+  int read_dentry(inodeno_t parent_ino, frag_t frag,
+		  const std::string &dname, InodeStore *inode, snapid_t *dnfirst=nullptr);
+};
+
+/**
+ * A class that knows how to manipulate CephFS metadata pools
+ */
+class MetadataDriver : public RecoveryDriver, public MetadataTool
+{
+  protected:
+    /**
+     * Create a .inode object, i.e. root or mydir
+     */
+    int inject_unlinked_inode(inodeno_t inono, int mode, int64_t data_pool_id);
+
+    /**
+     * Check for existence of .inode objects, before
+     * trying to go ahead and inject metadata.
+     */
+    int root_exists(inodeno_t ino, bool *result);
+    int find_or_create_dirfrag(
+        inodeno_t ino,
+        frag_t fragment,
+        bool *created);
+
+
+    /**
+     * Work out which fragment of a directory should contain a named
+     * dentry, recursing up the trace as necessary to retrieve
+     * fragtrees.
+     */
+    int get_frag_of(
+        inodeno_t dirino,
+        const std::string &dname,
+        frag_t *result_ft);
+
+  public:
+
+    // Implement RecoveryDriver interface
+    int init(
+        librados::Rados &rados,
+	std::string &metadata_pool_name,
+        const FSMap *fsmap,
+        fs_cluster_id_t fscid) override;
+
+    int inject_linkage(
+        inodeno_t dir_ino, const std::string &dname,
+        const frag_t fragment, const InodeStore &inode, snapid_t dnfirst=CEPH_NOSNAP);
+
+    int inject_with_backtrace(
+        const inode_backtrace_t &bt,
+        const InodeStore &dentry) override;
+
+    int inject_lost_and_found(
+        inodeno_t ino,
+        const InodeStore &dentry) override;
+
+    int init_roots(int64_t data_pool_id) override;
+
+    int check_roots(bool *result) override;
+
+    int load_table(MDSTable *table);
+    int save_table(MDSTable *table);
+};
+
+class DataScan : public MDSUtility, public MetadataTool
+{
+  protected:
+    RecoveryDriver *driver;
+    fs_cluster_id_t fscid;
+
+    string metadata_pool_name;
+    std::vector<int64_t> data_pools;
+
+    // IoCtx for data pool (where we scrape file backtraces from)
+    librados::IoCtx data_io;
+    // Remember the data pool ID for use in layouts
+    int64_t data_pool_id;
+
+    uint32_t n;
+    uint32_t m;
+
+    /**
+     * Scan data pool for backtraces, and inject inodes to metadata pool
+     */
+    int scan_inodes();
+
+    /**
+     * Scan data pool for file sizes and mtimes
+     */
+    int scan_extents();
+
+    /**
+     * Scan metadata pool for 0th dirfrags to link orphaned
+     * directory inodes.
+     */
+    int scan_frags();
+
+    /**
+     * Cleanup xattrs from data pool
+     */
+    int cleanup();
+
+    /**
+     * Check if an inode number is in the permitted ranges
+     */
+    bool valid_ino(inodeno_t ino) const;
+
+
+    int scan_links();
+
+    // Accept pools which are not in the FSMap
+    bool force_pool;
+    // Respond to decode errors by overwriting
+    bool force_corrupt;
+    // Overwrite root objects even if they exist
+    bool force_init;
+    // Only scan inodes without this scrub tag
+    string filter_tag;
+
+    /**
+     * @param r set to error on valid key with invalid value
+     * @return true if argument consumed, else false
+     */
+    bool parse_kwarg(
+        const std::vector<const char*> &args,
+        std::vector<const char *>::const_iterator &i,
+        int *r);
+
+    /**
+     * @return true if argument consumed, else false
+     */
+    bool parse_arg(
+      const std::vector<const char*> &arg,
+      std::vector<const char *>::const_iterator &i);
+
+    int probe_filter(librados::IoCtx &ioctx);
+
+    /**
+     * Apply a function to all objects in an ioctx's pool, optionally
+     * restricted to only those objects with a 00000000 offset and
+     * no tag matching DataScan::scrub_tag.
+     */
+    int forall_objects(
+        librados::IoCtx &ioctx,
+        bool untagged_only,
+        std::function<int(std::string, uint64_t, uint64_t)> handler);
+
+  public:
+    static void usage();
+    int main(const std::vector<const char *> &args);
+
+    DataScan()
+      : driver(NULL), fscid(FS_CLUSTER_ID_NONE),
+	data_pool_id(-1), n(0), m(1),
+        force_pool(false), force_corrupt(false),
+        force_init(false)
+    {
+    }
+
+    ~DataScan() override
+    {
+      delete driver;
+    }
+};
+