Commit 5d8da9b3 authored by Jean Bez's avatar Jean Bez Committed by Ramon Nou
Browse files

[readv and preadv] Implementation and tests. Fixes #84

parent 082832dd

include/client/gkfs_functions.hpp

+3 −0
Original line number Diff line number Diff line
@@ -84,6 +84,9 @@ ssize_t gkfs_pread_ws(int fd, void* buf, size_t count, off64_t offset); 


ssize_t gkfs_read(int fd, void* buf, size_t count);



ssize_t gkfs_readv(int fd, const struct iovec* iov, int iovcnt);



ssize_t gkfs_preadv(int fd, const struct iovec* iov, int iovcnt, off_t offset);



int gkfs_opendir(const std::string& path);

include/client/hooks.hpp

+5 −0
Original line number Diff line number Diff line
@@ -42,6 +42,11 @@ int hook_read(unsigned int fd, void* buf, size_t count); 


int hook_pread(unsigned int fd, char* buf, size_t count, loff_t pos);



int hook_readv(unsigned long fd, const struct iovec * iov, unsigned long iovcnt);



int hook_preadv(unsigned long fd, const struct iovec * iov, unsigned long iovcnt,

                 unsigned long pos_l, unsigned long pos_h);



int hook_write(unsigned int fd, const char* buf, size_t count);



int hook_pwrite(unsigned int fd, const char* buf, size_t count, loff_t pos);

src/client/gkfs_functions.cpp

+43 −0
Original line number Diff line number Diff line
@@ -521,6 +521,49 @@ ssize_t gkfs_read(int fd, void* buf, size_t count) { 
    return ret;

}



ssize_t gkfs_preadv(int fd, const struct iovec* iov, int iovcnt, off_t offset) {



    auto file = CTX->file_map()->get(fd);

    auto pos = offset; // keep truck of current position

    ssize_t read = 0;

    ssize_t ret;

    for (int i = 0; i < iovcnt; ++i) {

        auto count = (iov + i)->iov_len;

        if (count == 0) {

            continue;

        }

        auto buf = (iov + i)->iov_base;

        ret = gkfs_pread(file, reinterpret_cast<char*>(buf), count, pos);

        if (ret == -1) {

            break;

        }

        read += ret;

        pos += ret;



        if (static_cast<size_t>(ret) < count) {

            break;

        }

    }



    if (read == 0) {

        return -1;

    }

    return read;

}



ssize_t gkfs_readv(int fd, const struct iovec* iov, int iovcnt) {



    auto gkfs_fd = CTX->file_map()->get(fd);

    auto pos = gkfs_fd->pos(); // retrieve the current offset

    auto ret = gkfs_preadv(fd, iov, iovcnt, pos);

    assert(ret != 0);

    if (ret < 0) {

        return -1;

    }

    gkfs_fd->pos(pos + ret);

    return ret;

}



ssize_t gkfs_pread_ws(int fd, void* buf, size_t count, off64_t offset) {

    auto gkfs_fd = CTX->file_map()->get(fd);

    return gkfs_pread(gkfs_fd, reinterpret_cast<char*>(buf), count, offset);

src/client/hooks.cpp

+26 −2
Original line number Diff line number Diff line
@@ -209,6 +209,30 @@ int hook_pread(unsigned int fd, char* buf, size_t count, loff_t pos) { 
    return syscall_no_intercept(SYS_pread64, fd, buf, count, pos);

}



int hook_readv(unsigned long fd, const struct iovec* iov, unsigned long iovcnt) {



    LOG(DEBUG, "{}() called with fd: {}, iov: {}, iovcnt: {}",

        __func__, fd, fmt::ptr(iov), iovcnt);



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

        return with_errno(gkfs::syscall::gkfs_readv(fd, iov, iovcnt));

    }

    return syscall_no_intercept(SYS_readv, fd, iov, iovcnt);

}



int hook_preadv(unsigned long fd, const struct iovec* iov, unsigned long iovcnt,

                 unsigned long pos_l, unsigned long pos_h) {



    LOG(DEBUG, "{}() called with fd: {}, iov: {}, iovcnt: {}, "

               "pos_l: {}," "pos_h: {}",

        __func__, fd, fmt::ptr(iov), iovcnt, pos_l, pos_h);



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

        return with_errno(gkfs::syscall::gkfs_preadv(fd, iov, iovcnt, pos_l));

    }

    return syscall_no_intercept(SYS_preadv, fd, iov, iovcnt, pos_l);

}



int hook_write(unsigned int fd, const char* buf, size_t count) {



    LOG(DEBUG, "{}() called with fd: {}, buf: {}, count {}",
@@ -253,7 +277,7 @@ int hook_pwritev(unsigned long fd, const struct iovec* iov, unsigned long iovcnt 
    if (CTX->file_map()->exist(fd)) {

        return with_errno(gkfs::syscall::gkfs_pwritev(fd, iov, iovcnt, pos_l));

    }

    return syscall_no_intercept(SYS_pwritev, fd, iov, iovcnt);

    return syscall_no_intercept(SYS_pwritev, fd, iov, iovcnt, pos_l);

}



int hook_unlinkat(int dirfd, const char* cpath, int flags) {

src/client/intercept.cpp

+14 −0
Original line number Diff line number Diff line
@@ -506,6 +506,20 @@ int hook(long syscall_number, 
                                             static_cast<loff_t>(arg3));

            break;



        case SYS_readv:

            *result = gkfs::hook::hook_readv(static_cast<unsigned long>(arg0),

                                              reinterpret_cast<const struct iovec*>(arg1),

                                              static_cast<unsigned long>(arg2));

            break;



        case SYS_preadv:

            *result = gkfs::hook::hook_preadv(static_cast<unsigned long>(arg0),

                                               reinterpret_cast<const struct iovec*>(arg1),

                                               static_cast<unsigned long>(arg2),

                                               static_cast<unsigned long>(arg3),

                                               static_cast<unsigned long>(arg4));

            break;



        case SYS_pwrite64:

            *result = gkfs::hook::hook_pwrite(static_cast<unsigned int>(arg0),

                                              reinterpret_cast<const char*>(arg1),