Commit f1b5c944 authored by Marc Vef's avatar Marc Vef
Browse files

File create: move exist check from client to daemon. Configuration option added.

parent afe1aa28

include/client/rpc/forward_metadata.hpp

+0 −6
Original line number Diff line number Diff line
@@ -28,12 +28,6 @@ class Metadata; 
}



namespace rpc {

// enum definieren TODO

enum class ForwardCreateStatus {

    ok,

    exists,

    error = -1

};



int forward_create(const std::string& path, mode_t mode);

include/config.hpp

+4 −0
Original line number Diff line number Diff line
@@ -48,6 +48,10 @@ constexpr auto use_ctime = false; 
constexpr auto use_mtime = false;

constexpr auto use_link_cnt = false;

constexpr auto use_blocks = false;



// metadata logic

// Check for existence of file metadata before create. This done on RocksDB level

constexpr auto create_exist_check = true;

} // namespace metadata



namespace rpc {

include/daemon/backend/exceptions.hpp

+2 −2
Original line number Diff line number Diff line
@@ -30,9 +30,9 @@ public: 
    explicit NotFoundException(const std::string& s) : DBException(s) {};

};



class CreateException : public DBException {

class ExistsException : public DBException {

public:

    CreateException(const std::string& s) : DBException(s) {};

    explicit ExistsException(const std::string& s) : DBException(s) {};

};



} // namespace metadata

include/daemon/backend/metadata/db.hpp

+3 −1
Original line number Diff line number Diff line
@@ -35,12 +35,14 @@ private: 
public:

    static inline void throw_rdb_status_excpt(const rdb::Status& s);



    MetadataDB(const std::string& path);

    explicit MetadataDB(const std::string& path);



    std::string get(const std::string& key) const;



    void put(const std::string& key, const std::string& val);



    void put_if_not_exist(const std::string& key, const std::string& val);



    void remove(const std::string& key);



    bool exists(const std::string& key);

src/client/gkfs_functions.cpp

+18 −18
Original line number Diff line number Diff line
@@ -101,7 +101,7 @@ int gkfs_open(const std::string& path, mode_t mode, int flags) { 
    }



    // dummy metadata creation

    std::shared_ptr<gkfs::metadata::Metadata> md{};

    std::shared_ptr<gkfs::metadata::Metadata> md = nullptr;



    if (flags & O_CREAT) {

        if (flags & O_DIRECTORY) {
@@ -110,12 +110,9 @@ int gkfs_open(const std::string& path, mode_t mode, int flags) { 
            return -1;

        }

        // no access check required here. If one is using our FS they have the permissions.

        int err_code = gkfs_create(path, mode | S_IFREG);

        if (err_code == (int) gkfs::rpc::ForwardCreateStatus::error) {

            LOG(ERROR, "Error creating file: '{}'", strerror(errno));

            return -1;

        }

        if (err_code == (int) gkfs::rpc::ForwardCreateStatus::exists) {

        int err = gkfs_create(path, mode | S_IFREG);

        if (err) {

            if (errno == EEXIST) {

                // file exists, O_CREAT was set

                if (flags & O_EXCL) {

                    // File exists and O_EXCL & O_CREAT was set
@@ -123,13 +120,16 @@ int gkfs_open(const std::string& path, mode_t mode, int flags) { 
                    return -1;

                }

                // file exists, O_CREAT was set O_EXCL wasnt, so function does not fail

                // this case is actually undefined as per `man 2 open`

                md = gkfs::util::get_metadata(path);

            } else {

                LOG(ERROR, "Error creating file: '{}'", strerror(errno));

                return -1;

            }

        if (err_code == 0) {

            // file was created

        } else {

            // file was successfully created. Add to filemap

            return CTX->file_map()->add(std::make_shared<gkfs::filemap::OpenFile>(path, flags));

        }



    } else {

        md = gkfs::util::get_metadata(path);

        if (!md) {
@@ -137,7 +137,7 @@ int gkfs_open(const std::string& path, mode_t mode, int flags) { 
                // file doesn't exists and O_CREAT was not set

                return -1;

            } else {

                LOG(ERROR, "Error statting existing file");

                LOG(ERROR, "Error stating existing file");

                return -1;

            }

        }