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Merge pull request #11446 from ukernel/wip-cephfs-scan-links
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tools/cephfs: add scan_links command which fixes linkages errors

Reviewed-by: Greg Farnum <gfarnum@redhat.com>
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John Spray committed Oct 28, 2016
2 parents 649f24c + 9e3471c commit 94f08a2
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Showing 2 changed files with 230 additions and 6 deletions.
226 changes: 223 additions & 3 deletions src/tools/cephfs/DataScan.cc
View file
Expand Up @@ -35,6 +35,7 @@ void DataScan::usage()
<< " cephfs-data-scan scan_extents [--force-pool] <data pool name>\n"
<< " cephfs-data-scan scan_inodes [--force-pool] [--force-corrupt] <data pool name>\n"
<< " cephfs-data-scan pg_files <path> <pg id> [<pg id>...]\n"
<< " cephfs-data-scan scan_links\n"
<< "\n"
<< " --force-corrupt: overrite apparently corrupt structures\n"
<< " --force-init: write root inodes even if they exist\n"
Expand Down Expand Up @@ -233,8 +234,8 @@ int DataScan::main(const std::vector<const char*> &args)
}

// Initialize data_io for those commands that need it
if (command == "scan_inodes"
|| command == "scan_extents") {
if (command == "scan_inodes" ||
command == "scan_extents") {
if (data_pool_name.empty()) {
std::cerr << "Data pool not specified" << std::endl;
usage();
Expand Down Expand Up @@ -267,7 +268,7 @@ int DataScan::main(const std::vector<const char*> &args)
}

// Initialize metadata_io from MDSMap for scan_frags
if (command == "scan_frags") {
if (command == "scan_frags" || command == "scan_links") {
const auto fs = fsmap->get_filesystem(fscid);
if (fs == nullptr) {
std::cerr << "Filesystem id " << fscid << " does not exist" << std::endl;
Expand Down Expand Up @@ -297,6 +298,8 @@ int DataScan::main(const std::vector<const char*> &args)
return scan_extents();
} else if (command == "scan_frags") {
return scan_frags();
} else if (command == "scan_links") {
return scan_links();
} else if (command == "init") {
return driver->init_roots(fs->mds_map.get_first_data_pool());
} else {
Expand Down Expand Up @@ -850,6 +853,223 @@ bool DataScan::valid_ino(inodeno_t ino) const
|| ino == MDS_INO_CEPH;
}

int DataScan::scan_links()
{
MetadataDriver *metadata_driver = dynamic_cast<MetadataDriver*>(driver);
if (!metadata_driver) {
derr << "Unexpected --output-dir option for scan_links" << dendl;
return -EINVAL;
}

interval_set<inodeno_t> used_inos;
map<inodeno_t, int> remote_links;

struct link_info_t {
inodeno_t dirino;
frag_t frag;
string name;
version_t version;
int nlink;
bool is_dir;
link_info_t() : version(0), nlink(0), is_dir(false) {}
link_info_t(inodeno_t di, frag_t df, const string& n, const inode_t i) :
dirino(di), frag(df), name(n),
version(i.version), nlink(i.nlink), is_dir(S_IFDIR & i.mode) {}
dirfrag_t dirfrag() const {
return dirfrag_t(dirino, frag);
}
};
map<inodeno_t, list<link_info_t> > dup_primaries;
map<inodeno_t, link_info_t> bad_nlink_inos;

map<dirfrag_t, set<string> > to_remove;

enum {
SCAN_INOS = 1,
CHECK_LINK,
};

for (int step = SCAN_INOS; step <= CHECK_LINK; step++) {
const librados::NObjectIterator it_end = metadata_io.nobjects_end();
for (auto it = metadata_io.nobjects_begin(); it != it_end; ++it) {
const std::string oid = it->get_oid();

uint64_t dir_ino = 0;
uint64_t frag_id = 0;
int r = parse_oid(oid, &dir_ino, &frag_id);
if (r == -EINVAL) {
dout(10) << "Not a dirfrag: '" << oid << "'" << dendl;
continue;
} else {
// parse_oid can only do 0 or -EINVAL
assert(r == 0);
}

if (!valid_ino(dir_ino)) {
dout(10) << "Not a dirfrag (invalid ino): '" << oid << "'" << dendl;
continue;
}

std::map<std::string, bufferlist> items;
r = metadata_io.omap_get_vals(oid, "", (uint64_t)-1, &items);
if (r < 0) {
derr << "Error getting omap from '" << oid << "': " << cpp_strerror(r) << dendl;
return r;
}

for (auto& p : items) {
bufferlist::iterator q = p.second.begin();
string dname;
snapid_t last;
dentry_key_t::decode_helper(p.first, dname, last);

if (last != CEPH_NOSNAP)
continue;

try {
snapid_t dnfirst;
::decode(dnfirst, q);
char dentry_type;
::decode(dentry_type, q);
if (dentry_type == 'I') {
InodeStore inode;
inode.decode_bare(q);
inodeno_t ino = inode.inode.ino;

if (step == SCAN_INOS) {
if (used_inos.contains(ino, 1)) {
dup_primaries[ino].size();
} else {
used_inos.insert(ino);
}
} else if (step == CHECK_LINK) {
auto q = dup_primaries.find(ino);
if (q != dup_primaries.end()) {
q->second.push_back(link_info_t(dir_ino, frag_id, dname, inode.inode));
} else {
int nlink = 0;
auto r = remote_links.find(ino);
if (r != remote_links.end())
nlink = r->second;
if (!MDS_INO_IS_STRAY(dir_ino))
nlink++;
if (inode.inode.nlink != nlink) {
derr << "Bad nlink on " << ino << " expected " << nlink
<< " has " << inode.inode.nlink << dendl;
bad_nlink_inos[ino] = link_info_t(dir_ino, frag_id, dname, inode.inode);
bad_nlink_inos[ino].nlink = nlink;
}
}
}
} else if (dentry_type == 'L') {
inodeno_t ino;
unsigned char d_type;
::decode(ino, q);
::decode(d_type, q);

if (step == SCAN_INOS) {
remote_links[ino]++;
} else if (step == CHECK_LINK) {
if (!used_inos.contains(ino, 1)) {
derr << "Bad remote link dentry 0x" << std::hex << dir_ino
<< std::dec << "/" << dname
<< ", ino " << ino << " not found" << dendl;
std::string key;
dentry_key_t dn_key(CEPH_NOSNAP, dname.c_str());
dn_key.encode(key);
to_remove[dirfrag_t(dir_ino, frag_id)].insert(key);
}
}
} else {
derr << "Invalid tag char '" << dentry_type << "' dentry 0x" << dir_ino
<< std::dec << "/" << dname << dendl;
return -EINVAL;
}
} catch (const buffer::error &err) {
derr << "Error decoding dentry 0x" << std::hex << dir_ino
<< std::dec << "/" << dname << dendl;
return -EINVAL;
}
}
}
}
used_inos.clear();

for (auto& p : dup_primaries) {
link_info_t newest;
for (auto& q : p.second) {
if (q.version > newest.version) {
newest = q;
} else if (q.version == newest.version &&
!MDS_INO_IS_STRAY(q.dirino) &&
MDS_INO_IS_STRAY(newest.dirino)) {
newest = q;
}
}

for (auto& q : p.second) {
// in the middle of dir fragmentation?
if (newest.dirino == q.dirino && newest.name == q.name)
continue;

std::string key;
dentry_key_t dn_key(CEPH_NOSNAP, q.name.c_str());
dn_key.encode(key);
to_remove[q.dirfrag()].insert(key);
derr << "Remove duplicated ino 0x" << p.first << " from "
<< q.dirfrag() << "/" << q.name << dendl;
}

int nlink = 0;
auto q = remote_links.find(p.first);
if (q != remote_links.end())
nlink = q->second;
if (!MDS_INO_IS_STRAY(newest.dirino))
nlink++;

if (nlink != newest.nlink) {
derr << "Bad nlink on " << p.first << " expected " << nlink
<< " has " << newest.nlink << dendl;
bad_nlink_inos[p.first] = newest;
bad_nlink_inos[p.first].nlink = nlink;
}
}
dup_primaries.clear();
remote_links.clear();

for (auto& p : to_remove) {
object_t frag_oid = InodeStore::get_object_name(p.first.ino, p.first.frag, "");

int r = metadata_io.omap_rm_keys(frag_oid.name, p.second);
if (r != 0) {
derr << "Error removing duplicated dentries from " << p.first << dendl;
return r;
}
}
to_remove.clear();

for (auto &p : bad_nlink_inos) {
InodeStore inode;
int r = read_dentry(p.second.dirino, p.second.frag, p.second.name, &inode);
if (r < 0) {
derr << "Unexpected error reading dentry "
<< p.second.dirfrag() << "/" << p.second.name
<< ": " << cpp_strerror(r) << dendl;
return r;
}

if (inode.inode.ino != p.first || inode.inode.version != p.second.version)
continue;

inode.inode.nlink = p.second.nlink;
r = metadata_driver->inject_linkage(p.second.dirino, p.second.name, p.second.frag, inode);
if (r < 0)
return r;
}

return 0;
}

int DataScan::scan_frags()
{
bool roots_present;
Expand Down
10 changes: 7 additions & 3 deletions src/tools/cephfs/DataScan.h
View file
Expand Up @@ -194,9 +194,6 @@ class MetadataDriver : public RecoveryDriver, public MetadataTool
frag_t fragment,
bool *created);

int inject_linkage(
inodeno_t dir_ino, const std::string &dname,
const frag_t fragment, const InodeStore &inode);

/**
* Work out which fragment of a directory should contain a named
Expand All @@ -216,6 +213,10 @@ class MetadataDriver : public RecoveryDriver, public MetadataTool
const FSMap *fsmap,
fs_cluster_id_t fscid);

int inject_linkage(
inodeno_t dir_ino, const std::string &dname,
const frag_t fragment, const InodeStore &inode);

int inject_with_backtrace(
const inode_backtrace_t &bt,
const InodeStore &dentry);
Expand Down Expand Up @@ -264,6 +265,9 @@ class DataScan : public MDSUtility, public MetadataTool
*/
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
Expand Down

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