dfs_fs.h 文件参考

#include <dfs.h>
#include <dfs_file.h>

dfs_fs.h 的引用(Include)关系图:

此图展示该文件被哪些文件直接或间接地引用了:

浏览该文件的源代码.

结构体
struct	dfs_partition
struct	dfs_attr
struct	dfs_filesystem_ops
struct	dfs_filesystem_type

宏定义
#define	MS_RDONLY   1
#define	MS_NOSUID   2
#define	MS_NODEV   4
#define	MS_NOEXEC   8
#define	MS_SYNCHRONOUS   16
#define	MS_REMOUNT   32
#define	MS_MANDLOCK   64
#define	MS_DIRSYNC   128
#define	MS_NOATIME   1024
#define	MS_NODIRATIME   2048
#define	MS_BIND   4096
#define	MS_MOVE   8192
#define	MS_REC   16384
#define	MS_SILENT   32768
#define	MS_POSIXACL   (1<<16)
#define	MS_UNBINDABLE   (1<<17)
#define	MS_PRIVATE   (1<<18)
#define	MS_SLAVE   (1<<19)
#define	MS_SHARED   (1<<20)
#define	MS_RELATIME   (1<<21)
#define	MS_KERNMOUNT   (1<<22)
#define	MS_I_VERSION   (1<<23)
#define	MS_STRICTATIME   (1<<24)
#define	MS_LAZYTIME   (1<<25)
#define	MS_NOREMOTELOCK   (1<<27)
#define	MS_NOSEC   (1<<28)
#define	MS_BORN   (1<<29)
#define	MS_ACTIVE   (1<<30)
#define	MS_NOUSER   (1U<<31)
#define	MS_RMT_MASK   (MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION|MS_LAZYTIME)
#define	FS_NEED_DEVICE   0x1

函数
struct dfs_filesystem_type *	dfs_filesystems (void)
int	dfs_unregister (struct dfs_filesystem_type *fs)
int	dfs_register (struct dfs_filesystem_type *fs)
const char *	dfs_filesystem_get_mounted_path (struct rt_device *device)
int	dfs_remount (const char *path, rt_ubase_t flags, void *data)
int	dfs_mount (const char *device_name, const char *path, const char *filesystemtype, unsigned long rwflag, const void *data)
int	dfs_umount (const char *specialfile, int flags)
int	dfs_unmount (const char *specialfile)
int	dfs_is_mounted (struct dfs_mnt *mnt)
int	dfs_mkfs (const char *fs_name, const char *device_name)
int	dfs_statfs (const char *path, struct statfs *buffer)
int	dfs_filesystem_get_partition (struct dfs_partition *part, uint8_t *buf, uint32_t pindex)

宏定义说明

MS_RDONLY

#define MS_RDONLY   1

在文件 dfs_fs.h 第 23 行定义.

MS_NOSUID

#define MS_NOSUID   2

在文件 dfs_fs.h 第 24 行定义.

MS_NODEV

#define MS_NODEV   4

在文件 dfs_fs.h 第 25 行定义.

MS_NOEXEC

#define MS_NOEXEC   8

在文件 dfs_fs.h 第 26 行定义.

MS_SYNCHRONOUS

#define MS_SYNCHRONOUS   16

在文件 dfs_fs.h 第 27 行定义.

MS_REMOUNT

#define MS_REMOUNT   32

在文件 dfs_fs.h 第 28 行定义.

MS_MANDLOCK

#define MS_MANDLOCK   64

在文件 dfs_fs.h 第 29 行定义.

MS_DIRSYNC

#define MS_DIRSYNC   128

在文件 dfs_fs.h 第 30 行定义.

MS_NOATIME

#define MS_NOATIME   1024

在文件 dfs_fs.h 第 31 行定义.

MS_NODIRATIME

#define MS_NODIRATIME   2048

在文件 dfs_fs.h 第 32 行定义.

MS_BIND

#define MS_BIND   4096

在文件 dfs_fs.h 第 33 行定义.

MS_MOVE

#define MS_MOVE   8192

在文件 dfs_fs.h 第 34 行定义.

MS_REC

#define MS_REC   16384

在文件 dfs_fs.h 第 35 行定义.

MS_SILENT

#define MS_SILENT   32768

在文件 dfs_fs.h 第 36 行定义.

MS_POSIXACL

#define MS_POSIXACL   (1<<16)

在文件 dfs_fs.h 第 37 行定义.

MS_UNBINDABLE

#define MS_UNBINDABLE   (1<<17)

在文件 dfs_fs.h 第 38 行定义.

MS_PRIVATE

#define MS_PRIVATE   (1<<18)

在文件 dfs_fs.h 第 39 行定义.

MS_SLAVE

#define MS_SLAVE   (1<<19)

在文件 dfs_fs.h 第 40 行定义.

MS_SHARED

#define MS_SHARED   (1<<20)

在文件 dfs_fs.h 第 41 行定义.

MS_RELATIME

#define MS_RELATIME   (1<<21)

在文件 dfs_fs.h 第 42 行定义.

MS_KERNMOUNT

#define MS_KERNMOUNT   (1<<22)

在文件 dfs_fs.h 第 43 行定义.

MS_I_VERSION

#define MS_I_VERSION   (1<<23)

在文件 dfs_fs.h 第 44 行定义.

MS_STRICTATIME

#define MS_STRICTATIME   (1<<24)

在文件 dfs_fs.h 第 45 行定义.

MS_LAZYTIME

#define MS_LAZYTIME   (1<<25)

在文件 dfs_fs.h 第 46 行定义.

MS_NOREMOTELOCK

#define MS_NOREMOTELOCK   (1<<27)

在文件 dfs_fs.h 第 47 行定义.

MS_NOSEC

#define MS_NOSEC   (1<<28)

在文件 dfs_fs.h 第 48 行定义.

MS_BORN

#define MS_BORN   (1<<29)

在文件 dfs_fs.h 第 49 行定义.

MS_ACTIVE

#define MS_ACTIVE   (1<<30)

在文件 dfs_fs.h 第 50 行定义.

MS_NOUSER

#define MS_NOUSER   (1U<<31)

在文件 dfs_fs.h 第 51 行定义.

MS_RMT_MASK

#define MS_RMT_MASK   (MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION|MS_LAZYTIME)

在文件 dfs_fs.h 第 53 行定义.

FS_NEED_DEVICE

#define FS_NEED_DEVICE   0x1

在文件 dfs_fs.h 第 84 行定义.

函数说明

dfs_filesystems()

struct dfs_filesystem_type * dfs_filesystems

(

void

)

在文件 dfs_fs.c 第 50 行定义.

{
    return file_systems;
}

dfs_unregister()

int dfs_unregister

(

struct dfs_filesystem_type *

fs

)

在文件 dfs_fs.c 第 74 行定义.

{
    int ret = 0;
    struct dfs_filesystem_type **type;
 
    if (fs)
    {
        LOG_D("unregister %s file system.", fs->fs_ops->name);
 
        for (type = &file_systems; *type; type = &(*type)->next)
        {
            if (strcmp((*type)->fs_ops->name, fs->fs_ops->name) == 0)
            {
                *type = (*type)->next;
                break;
            }
        }
 
        if (!*type) ret = -EINVAL;
    }
 
    return ret;
}

引用了 dfs_filesystem_type::fs_ops, LOG_D, dfs_filesystem_ops::name , 以及 dfs_filesystem_type::next.

dfs_register()

int dfs_register

(

struct dfs_filesystem_type *

fs

)

在文件 dfs_fs.c 第 55 行定义.

{
    int ret = 0;
    struct dfs_filesystem_type **type = _find_filesystem(fs->fs_ops->name);
 
    LOG_D("register %s file system.", fs->fs_ops->name);
 
    if (*type)
    {
        ret = -EBUSY;
    }
    else
    {
        *type = fs;
    }
 
    return ret;
}

引用了 dfs_filesystem_type::fs_ops, LOG_D , 以及 dfs_filesystem_ops::name.

dfs_filesystem_get_mounted_path()

const char * dfs_filesystem_get_mounted_path

(

struct rt_device *

device

)

this function will return the mounted path for specified device.

参数

device

the device object which is mounted.

返回

the mounted path or NULL if none device mounted.

在文件 dfs_fs.c 第 506 行定义.

{
    const char *path = NULL;
 
    return path;
}

dfs_remount()

int dfs_remount	(	const char *	path,
		rt_ubase_t	flags,
		void *	data )

在文件 dfs_fs.c 第 99 行定义.

{
    int rc = 0;
    char *fullpath = RT_NULL;
    struct dfs_mnt *mnt = RT_NULL;
 
    if (flags & REMNT_UNSUPP_FLAGS)
    {
        return -EINVAL;
    }
 
    fullpath = dfs_normalize_path(RT_NULL, path);
    if (!fullpath)
    {
        rc = -ENOENT;
    }
    else
    {
        DLOG(msg, "dfs", "mnt", DLOG_MSG, "mnt = dfs_mnt_lookup(%s)", fullpath);
        mnt = dfs_mnt_lookup(fullpath);
        if (mnt)
        {
            dfs_lock();
            dfs_mnt_setflags(mnt, flags);
            dfs_unlock();
        }
        else
        {
            struct stat buf = {0};
            if (dfs_file_stat(fullpath, &buf) == 0 && S_ISBLK(buf.st_mode))
            {
                /* path was not already mounted on target */
                rc = -EINVAL;
            }
            else
            {
                /* path is not a directory */
                rc = -ENOTDIR;
            }
        }
    }
 
    return rc;
}

引用了 dfs_file_stat(), dfs_lock(), dfs_mnt_lookup(), dfs_mnt_setflags(), dfs_normalize_path(), dfs_unlock(), DLOG, dfs_mnt::flags, dfs_mnt::fullpath, REMNT_UNSUPP_FLAGS, RT_NULL , 以及 stat().

函数调用图:

dfs_mount()

int dfs_mount	(	const char *	device_name,
		const char *	path,
		const char *	filesystemtype,
		unsigned long	rwflag,
		const void *	data )

在文件 dfs_fs.c 第 152 行定义.

{
    int ret = RT_EOK;
    char *fullpath = RT_NULL;
    rt_device_t dev_id = RT_NULL;
    struct dfs_mnt *mnt_parent = RT_NULL, *mnt_child = RT_NULL;
    struct dfs_dentry *mntpoint_dentry = RT_NULL;
    struct dfs_filesystem_type *type = *_find_filesystem(filesystemtype);
 
    if (type)
    {
        fullpath = dfs_normalize_path(RT_NULL, path);
        if (!fullpath)
        {
            rt_set_errno(EPERM);
            ret = -1;
        }
    }
    else
    {
        rt_set_errno(ENODEV);
        ret = -1;
    }
 
    if (fullpath)
    {
        DLOG(note, "mnt", "mount %s(%s) on path: %s", device_name, filesystemtype, fullpath);
 
        /* open specific device */
        if (device_name) dev_id = rt_device_find(device_name);
 
        if (!(type->fs_ops->flags & FS_NEED_DEVICE) ||
            ((type->fs_ops->flags & FS_NEED_DEVICE) && dev_id))
        {
            DLOG(msg, "dfs", "mnt", DLOG_MSG, "mnt_parent = dfs_mnt_lookup(%s)", fullpath);
            mnt_parent = dfs_mnt_lookup(fullpath);
            if ((!mnt_parent && (strcmp(fullpath, "/") == 0 || strcmp(fullpath, "/dev") == 0))
                || (mnt_parent && strcmp(fullpath, "/") == 0 && strcmp(mnt_parent->fullpath, fullpath) != 0))
            {
                LOG_D("no mnt found @ mount point %s, should be root.", fullpath);
                DLOG(msg, "mnt", "dfs", DLOG_MSG_RET, "no mnt");
 
                /* it's the root file system */
                /* the mount point dentry is the same as root dentry. */
 
                DLOG(msg, "dfs", "mnt", DLOG_MSG, "mnt_parent = dfs_mnt_create(path)");
                mnt_parent = dfs_mnt_create(fullpath); /* mnt->ref_count should be 1. */
                if (mnt_parent)
                {
                    DLOG(msg, "mnt", "dfs", DLOG_MSG_RET, "return mnt, ref_count=1");
 
                    mnt_parent->fs_ops = type->fs_ops;
                    mnt_parent->dev_id = dev_id;
                    if (mnt_parent->fs_ops->mount)
                    {
                        DLOG(msg, "dfs", type->fs_ops->name, DLOG_MSG, "fs_ops->mount(mnt_parent, rwflag, data)");
                        ret = mnt_parent->fs_ops->mount(mnt_parent, rwflag, data);
                        if (ret == RT_EOK)
                        {
                            DLOG(msg, type->fs_ops->name, "dfs", DLOG_MSG_RET, "mount OK, ret root_dentry");
 
                            mnt_child = mnt_parent;
                            mnt_child->flags |= MNT_IS_MOUNTED;
 
                            DLOG(note_right, "mnt", "mount sucessfully");
                            DLOG(msg, "dfs", "mnt", DLOG_MSG, "dfs_mnt_insert(, mnt_child)");
                            dfs_mnt_insert(RT_NULL, mnt_child);
 
                            /* unref it, because the ref_count = 1 when create */
                            DLOG(msg, "dfs", "mnt", DLOG_MSG, "dfs_mnt_unref(mnt_parent)");
                            dfs_mnt_unref(mnt_parent);
 
                            /*
                             * About root mnt:
                             * There are two ref_count:
                             * 1. the gobal root reference.
                             * 1. the mnt->parent reference.
                             */
                        }
                        else
                        {
                            LOG_W("mount %s failed with file system type: %s", fullpath, type->fs_ops->name);
                            DLOG(msg, "dfs", "mnt", DLOG_MSG, "dfs_mnt_destroy(mnt_parent)");
                            dfs_mnt_destroy(mnt_parent);
                            mnt_parent = RT_NULL;
                            rt_set_errno(EPERM);
                            ret = -1;
                        }
                    }
                    else
                    {
                        LOG_W("no mount method on file system type: %s", type->fs_ops->name);
                        DLOG(msg, "dfs", "mnt", DLOG_MSG, "dfs_mnt_destroy(mnt_parent), no mount method");
                        dfs_mnt_destroy(mnt_parent);
                        mnt_parent = RT_NULL;
                        rt_set_errno(EIO);
                        ret = -1;
                    }
                }
                else
                {
                    LOG_E("create a mnt point failed.");
                    rt_set_errno(ENOMEM);
                    ret = -1;
                }
            }
            else if (mnt_parent && (strcmp(mnt_parent->fullpath, fullpath) != 0))
            {
                DLOG(msg, "dfs", "dentry", DLOG_MSG, "mntpoint_dentry = dfs_dentry_lookup(mnt_parent, %s, 0)", fullpath);
                mntpoint_dentry = dfs_dentry_lookup(mnt_parent, fullpath, 0);
                if (mntpoint_dentry)
                {
                    DLOG(msg, "dentry", "dfs", DLOG_MSG_RET, "dentry exist");
                    DLOG(msg, "dfs", "mnt", DLOG_MSG, "mnt_child = dfs_mnt_create(path)");
                    mnt_child = dfs_mnt_create(fullpath);
                    if (mnt_child)
                    {
                        LOG_D("create mnt point %p", mnt_child);
 
                        mnt_child->fs_ops = type->fs_ops;
                        mnt_child->dev_id = dev_id;
 
                        if (mnt_child->fs_ops->mount)
                        {
                            DLOG(msg, "dfs", type->fs_ops->name, DLOG_MSG, "root_dentry = fs_ops->mount(mnt_child, rwflag, data)");
                            ret = mnt_child->fs_ops->mount(mnt_child, rwflag, data);
                            if (ret == RT_EOK)
                            {
                                mnt_child->flags |= MNT_IS_MOUNTED;
 
                                LOG_D("mount %s sucessfully", fullpath);
                                DLOG(msg, mnt_child->fs_ops->name, "dfs", DLOG_MSG_RET, "mount OK");
 
                                DLOG(msg, "dfs", "mnt", DLOG_MSG, "dfs_mnt_insert(mnt_parent, mnt_child)");
                                dfs_mnt_insert(mnt_parent, mnt_child);
 
                                /* unref it, because the ref_count = 1 when create */
                                DLOG(msg, "dfs", "mnt", DLOG_MSG, "dfs_mnt_unref(mnt_child)");
                                dfs_mnt_unref(mnt_child);
                            }
                            else
                            {
                                LOG_W("mount %s failed with file system type: %s", fullpath, type->fs_ops->name);
                                DLOG(msg, mnt_child->fs_ops->name, "dfs", DLOG_MSG_RET, "mount failed");
                                dfs_mnt_destroy(mnt_child);
                                rt_set_errno(EPERM);
                                ret = -1;
                            }
                        }
                        else
                        {
                            LOG_W("no mount method on file system type: %s", type->fs_ops->name);
                            dfs_mnt_destroy(mnt_child);
                            rt_set_errno(EIO);
                            ret = -1;
                        }
                    }
                    else
                    {
                        LOG_E("create a mnt point failed.");
                        rt_set_errno(ENOMEM);
                        ret = -1;
                    }
                    dfs_dentry_unref(mntpoint_dentry);
                }
                else
                {
                    LOG_W("no mount point (%s) in file system: %s", fullpath, mnt_parent->fullpath);
                    rt_set_errno(ENOTDIR);
                    ret = -1;
                }
            }
            else
            {
                LOG_E("mount point (%s) already mounted!", fullpath);
                rt_set_errno(EEXIST);
                ret = -1;
            }
        }
        else
        {
            LOG_E("No device found for this file system.");
            rt_set_errno(ENODEV);
            ret = -1;
        }
        rt_free(fullpath);
    }
 
    return ret;
}

引用了 dfs_mnt::dev_id, dfs_dentry_lookup(), dfs_dentry_unref(), dfs_mnt_create(), dfs_mnt_destroy(), dfs_mnt_insert(), dfs_mnt_lookup(), dfs_mnt_unref(), dfs_normalize_path(), DLOG, dfs_filesystem_ops::flags, dfs_mnt::flags, FS_NEED_DEVICE, dfs_filesystem_type::fs_ops, dfs_mnt::fs_ops, dfs_mnt::fullpath, LOG_D, LOG_E, LOG_W, MNT_IS_MOUNTED, dfs_filesystem_ops::mount, dfs_filesystem_ops::name, rt_device_find(), rt_free() , 以及 RT_NULL.

函数调用图:

dfs_umount()

int dfs_umount	(	const char *	specialfile,
		int	flags )

在文件 dfs_fs.c 第 347 行定义.

{
    int ret = -1;
    char *fullpath = RT_NULL;
    struct dfs_mnt *mnt = RT_NULL;
 
    fullpath = dfs_normalize_path(NULL, specialfile);
    if (fullpath)
    {
        DLOG(msg, "dfs", "mnt", DLOG_MSG, "mnt = dfs_mnt_lookup(%s)", fullpath);
        mnt = dfs_mnt_lookup(fullpath);
        if (mnt)
        {
            if (strcmp(mnt->fullpath, fullpath) == 0)
            {
                /* is the mount point */
                rt_base_t ref_count = rt_atomic_load(&(mnt->ref_count));
 
                if (!(mnt->flags & MNT_IS_LOCKED) && rt_list_isempty(&mnt->child) && (ref_count == 1 || (flags & MNT_FORCE)))
                {
#ifdef RT_USING_PAGECACHE
                    dfs_pcache_unmount(mnt);
#endif
                    /* destroy this mount point */
                    DLOG(msg, "dfs", "mnt", DLOG_MSG, "dfs_mnt_destroy(mnt)");
                    ret = dfs_mnt_destroy(mnt);
                }
                else
                {
                    LOG_I("the file system is busy!");
                    ret = -EBUSY;
                }
            }
            else
            {
                LOG_I("the path:%s is not a mountpoint!", fullpath);
                ret = -EINVAL;
            }
        }
        else
        {
            LOG_I("no filesystem found.");
        }
        rt_free(fullpath);
    }
    else
    {
        rt_set_errno(-ENOTDIR);
    }
 
    return ret;
}

引用了 dfs_mnt::child, dfs_mnt_destroy(), dfs_mnt_lookup(), dfs_normalize_path(), DLOG, dfs_mnt::flags, dfs_mnt::fullpath, LOG_I, MNT_FORCE, MNT_IS_LOCKED, dfs_mnt::ref_count, rt_atomic_load, rt_free(), rt_list_isempty() , 以及 RT_NULL.

函数调用图:

这是这个函数的调用关系图:

dfs_unmount()

int dfs_unmount

(

const char *

specialfile

)

在文件 dfs_fs.c 第 401 行定义.

{
    return dfs_umount(specialfile, 0);
}

引用了 dfs_umount().

函数调用图:

dfs_is_mounted()

int dfs_is_mounted

(

struct dfs_mnt *

mnt

)

在文件 dfs_fs.c 第 406 行定义.

{
    int ret = 0;
 
    if (mnt && !(mnt->flags & MNT_IS_MOUNTED))
    {
        ret = -1;
    }
 
    return ret;
}

引用了 dfs_mnt::flags , 以及 MNT_IS_MOUNTED.

dfs_mkfs()

int dfs_mkfs	(	const char *	fs_name,
		const char *	device_name )

在文件 dfs_fs.c 第 418 行定义.

{
    rt_device_t dev_id = NULL;
    struct dfs_filesystem_type *type;
    int ret = -RT_ERROR;
 
    type = *_find_filesystem(fs_name);
    if (!type)
    {
        rt_kprintf("no file system: %s found!\n", fs_name);
        return ret;
    }
    else
    {
        if (type->fs_ops->flags & FS_NEED_DEVICE)
        {
            /* check device name, and it should not be NULL */
            if (device_name != NULL)
                dev_id = rt_device_find(device_name);
 
            if (dev_id == NULL)
            {
                rt_set_errno(-ENODEV);
                rt_kprintf("Device (%s) was not found", device_name);
                return ret;
            }
        }
        else
        {
            dev_id = RT_NULL;
        }
    }
 
    if (type->fs_ops->mkfs)
    {
        ret = type->fs_ops->mkfs(dev_id, type->fs_ops->name);
#ifdef RT_USING_PAGECACHE
        if (ret == RT_EOK)
        {
            struct dfs_mnt *mnt = RT_NULL;
 
            mnt = dfs_mnt_dev_lookup(dev_id);
            if (mnt)
            {
                dfs_pcache_unmount(mnt);
            }
        }
#endif
    }
 
    return ret;
}

引用了 dfs_mnt::dev_id, dfs_mnt_dev_lookup(), dfs_filesystem_ops::flags, FS_NEED_DEVICE, dfs_filesystem_type::fs_ops, dfs_filesystem_ops::mkfs, dfs_filesystem_ops::name, rt_device_find(), rt_kprintf , 以及 RT_NULL.

函数调用图:

dfs_statfs()

int dfs_statfs	(	const char *	path,
		struct statfs *	buffer )

在文件 dfs_fs.c 第 471 行定义.

{
    struct dfs_mnt *mnt;
    char *fullpath;
    int ret = -RT_ERROR;
 
    fullpath = dfs_normalize_path(NULL, path);
    if (!fullpath)
    {
        return ret;
    }
 
    DLOG(msg, "dfs_file", "mnt", DLOG_MSG, "dfs_mnt_lookup(%s)", fullpath);
    mnt = dfs_mnt_lookup(fullpath);
    if (mnt)
    {
        if (mnt->fs_ops->statfs)
        {
            if (dfs_is_mounted(mnt) == 0)
            {
                ret = mnt->fs_ops->statfs(mnt, buffer);
            }
        }
    }
 
    return ret;
}

引用了 dfs_is_mounted(), dfs_mnt_lookup(), dfs_normalize_path(), DLOG, dfs_mnt::fs_ops, dfs_mnt::fullpath, dfs_filesystem_ops::statfs , 以及 statfs().

函数调用图:

这是这个函数的调用关系图:

dfs_filesystem_get_partition()

int dfs_filesystem_get_partition	(	struct dfs_partition *	part,
		uint8_t *	buf,
		uint32_t	pindex )

this function will fetch the partition table on specified buffer.

参数

part	the returned partition structure.
buf	the buffer contains partition table.
pindex	the index of partition table to fetch.

返回

RT_EOK on successful or -RT_ERROR on failed.

在文件 dfs_fs.c 第 522 行定义.

{
#define DPT_ADDRESS     0x1be       /* device partition offset in Boot Sector */
#define DPT_ITEM_SIZE   16          /* partition item size */
 
    uint8_t *dpt;
    uint8_t type;
 
    RT_ASSERT(part != NULL);
    RT_ASSERT(buf != NULL);
 
    dpt = buf + DPT_ADDRESS + pindex * DPT_ITEM_SIZE;
 
    /* check if it is a valid partition table */
    if ((*dpt != 0x80) && (*dpt != 0x00))
        return -EIO;
 
    /* get partition type */
    type = *(dpt + 4);
    if (type == 0)
        return -EIO;
 
    /* set partition information
     *    size is the number of 512-Byte */
    part->type = type;
    part->offset = *(dpt + 8) | *(dpt + 9) << 8 | *(dpt + 10) << 16 | *(dpt + 11) << 24;
    part->size = *(dpt + 12) | *(dpt + 13) << 8 | *(dpt + 14) << 16 | *(dpt + 15) << 24;
 
    rt_kprintf("found part[%d], begin: %ld, size: ",
               pindex, part->offset * 512);
    if ((part->size >> 11) == 0)
        rt_kprintf("%ld%s", part->size >> 1, "KB\n"); /* KB */
    else
    {
        unsigned int part_size;
        part_size = part->size >> 11;                /* MB */
        if ((part_size >> 10) == 0)
            rt_kprintf("%d.%ld%s", part_size, (part->size >> 1) & 0x3FF, "MB\n");
        else
            rt_kprintf("%d.%d%s", part_size >> 10, part_size & 0x3FF, "GB\n");
    }
 
    return RT_EOK;
}

引用了 DPT_ADDRESS, DPT_ITEM_SIZE, dfs_partition::offset, RT_ASSERT, rt_kprintf, dfs_partition::size , 以及 dfs_partition::type.