Resolve "mmap support"

Ramon Nourequested to merge
rnou/199-mmap-support into master

Closes #199

Partial implementation

Merge request reports

include/client/gkfs_functions.hpp

+10 −0
Changes for include/client/gkfs_functions.hpp: 10 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -182,6 +182,16 @@ int 
gkfs_rename(const std::string& old_path, const std::string& new_path);

#endif // HAS_RENAME



// gkfs_mmap

void*

gkfs_mmap(void* addr, size_t length, int prot, int flags, int fd, off_t offset);



int

gkfs_munmap(void* addr, size_t length);



int

gkfs_msync(void* addr, size_t length, int flags);



} // namespace gkfs::syscall



// gkfs_getsingleserverdir is using extern "C" to demangle it for C usage

include/client/hooks.hpp

+8 −0
Changes for include/client/hooks.hpp: 8 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -233,6 +233,14 @@ hook_fallocate(int fd, int mode, off_t offset, off_t len); 
int

hook_fadvise64(int fd, off_t offset, off_t len, int advice);



void*

hook_mmap(void* addr, size_t length, int prot, int flags, int fd, off_t offset);



int

hook_munmap(void* addr, size_t length);



int

hook_msync(void* addr, size_t length, int flags);

} // namespace gkfs::hook



#endif

include/client/user_functions.hpp

+10 −0
Changes for include/client/user_functions.hpp: 10 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -133,6 +133,16 @@ gkfs_rename(const std::string& old_path, const std::string& new_path); 
int

gkfs_fsync(unsigned int fd);



// add mmap

void*

gkfs_mmap(void* addr, size_t length, int prot, int flags, int fd, off_t offset);



int

gkfs_munmap(void* addr, size_t length);



int

gkfs_msync(void* addr, size_t length, int flags);



} // namespace syscall

namespace malleable {

src/client/gkfs_functions.cpp

+60 −0
Changes for src/client/gkfs_functions.cpp: 60 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -114,6 +114,8 @@ struct dirent_extended { 


namespace {



// set to store void * addr, fd, length and offset

std::set<std::tuple<void*, int, size_t, off_t>> mmap_set;

/**

 * Checks if metadata for parent directory exists (can be disabled with

 * GKFS_CREATE_CHECK_PARENTS). errno may be set
@@ -1930,6 +1932,64 @@ gkfs_get_file_list(const std::string& path) { 
    return file_list;

}





void*

gkfs_mmap(void* addr, size_t length, int prot, int flags, int fd,

          off_t offset) {

    void* ptr = malloc(length);

    if(ptr == nullptr) {

        return MAP_FAILED;

    }

    // store info on mmap_set

    mmap_set.insert(std::make_tuple(ptr, fd, length, offset));

    gkfs::syscall::gkfs_pread(fd, ptr, length, offset);

    return ptr;

}



int

gkfs_msync(void* addr, size_t length, int flags) {

    // check if addr is from gekkofs (mmap_set)

    // if so, get the fd and offset

    // pwrite length to the original offset



    for(const auto& tuple : mmap_set) {

        if(std::get<0>(tuple) == addr) {

            int fd = std::get<1>(tuple);

            off_t offset = std::get<3>(tuple);

            gkfs::syscall::gkfs_pwrite(fd, addr, length, offset);

            return 0;

        }

    }

    return -1;

}





int

gkfs_munmap(void* addr, size_t length) {

    // check if addr is from gekkofs (mmap_set)

    // if so, get the fd and offset

    // pwrite length to the original offset

    // return

    // if not just go to the normal msync

    if(mmap_set.size() != 0) {

        // use find_if std::algorithm

        // if found, call msync



        auto it = std::find_if(

                mmap_set.begin(), mmap_set.end(),

                [&addr](const std::tuple<void*, int, size_t, off_t>& t) {

                    return std::get<0>(t) == addr;

                });

        if(it != mmap_set.end()) {

            gkfs_msync(addr, length, 0);

            free(addr);

            mmap_set.erase(it);

            return 0;

        }

    }

    return -1;

}



} // namespace gkfs::syscall

src/client/hooks.cpp

+38 −0
Changes for src/client/hooks.cpp: 38 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -1098,4 +1098,42 @@ hook_fadvise64(int fd, off_t offset, off_t len, int advice) { 
    }

    return syscall_no_intercept_wrapper(SYS_fadvise64, fd, offset, len, advice);

}



// mmap, munmap, msync

void*

hook_mmap(void* addr, size_t length, int prot, int flags, int fd,

          off_t offset) {

    LOG(DEBUG,

        "{}() called with addr '{}' length '{}' prot '{}' flags '{}' fd '{}' offset '{}'",

        __func__, fmt::ptr(addr), length, prot, flags, fd, offset);



    if(CTX->file_map()->exist(fd)) {

        return gkfs::syscall::gkfs_mmap(addr, length, prot, flags, fd, offset);

    }

    return reinterpret_cast<void*>(syscall_no_intercept_wrapper(

            SYS_mmap, addr, length, prot, flags, fd, offset));

}



int

hook_munmap(void* addr, size_t length) {

    LOG(DEBUG, "{}() called with addr '{}' length '{}'", __func__,

        fmt::ptr(addr), length);



    auto res = gkfs::syscall::gkfs_munmap(addr, length);

    if(res == 0)

        return res;

    return syscall_no_intercept_wrapper(SYS_munmap, addr, length);

}



int

hook_msync(void* addr, size_t length, int flags) {

    LOG(DEBUG, "{}() called with addr '{}' length '{}' flags '{}'", __func__,

        fmt::ptr(addr), length, flags);



    auto res = gkfs::syscall::gkfs_msync(addr, length, flags);

    if(res == 0)

        return res;

    return syscall_no_intercept_wrapper(SYS_msync, addr, length, flags);

}



} // namespace gkfs::hook