Device Virtual File System

Device Virtual File System 的协作图:

专题
	File Descriptor
	File System API
	File API
	File POSIX API

函数
rt_err_t	dfs_file_lock (void)
void	dfs_file_unlock (void)
int	dfs_init (void)
	INIT_PREV_EXPORT (dfs_init)
void	fdt_fd_release (struct dfs_fdtable *fdt, int fd)
int	fdt_fd_associate_file (struct dfs_fdtable *fdt, int fd, struct dfs_file *file)
int	fd_new (void)
struct dfs_file *	fd_get (int fd)
struct dfs_fdtable *	dfs_fdtable_get (void)
struct dfs_fdtable *	dfs_fdtable_get_global (void)
int	dfs_fdtable_dup (struct dfs_fdtable *fdt_dst, struct dfs_fdtable *fdt_src, int fd_src)
int	dfs_fdtable_drop_fd (struct dfs_fdtable *fdt, int fd)
int	dfs_dup (int oldfd, int startfd)
int	dfs_dup_to (int oldfd, struct dfs_fdtable *fdtab)
int	dfs_dup_from (int oldfd, struct dfs_fdtable *fdtab)
int	sys_dup (int oldfd)
rt_err_t	sys_dup2 (int oldfd, int newfd)
const char *	dfs_subdir (const char *directory, const char *filename)
	RTM_EXPORT (dfs_subdir)
char *	dfs_normalize_path (const char *directory, const char *filename)
	RTM_EXPORT (dfs_normalize_path)
int	list_fd (void)
	MSH_CMD_EXPORT (list_fd, list file descriptor)
int	dfs_fd_dump (int argc, char **argv)
	MSH_CMD_EXPORT_ALIAS (dfs_fd_dump, fd_dump, fd dump)

详细描述

DFS is a virtual file system in RT-Thread RTOS.

The DFS (Device Virtual File System) is a vfs file system of RT-Thread RTOS, which is focused on embedded device. VFS is an abstraction layer on top of a more concrete file system. The purpose of a VFS is to allow client applications to access different types of concrete file systems in a uniform way.

Figure 4: Device Virtual File System Architecture

The DFS specifies an interface between the kernel and a concrete file system. Therefore, it is easy to add support for new file system types to the kernel simply by fulfilling the interface.

函数说明

dfs_file_lock()

rt_err_t dfs_file_lock

(

void

)

在文件 dfs.c 第 147 行定义.

{
    rt_err_t result = -RT_EBUSY;
 
    if (!_dfs_init_ok)
    {
        return -RT_ENOSYS;
    }
 
    while (result == -RT_EBUSY)
    {
        result = rt_mutex_take(&fdlock, RT_WAITING_FOREVER);
    }
 
    return result;
}

引用了 rt_mutex_take() , 以及 RT_WAITING_FOREVER.

函数调用图:

这是这个函数的调用关系图:

dfs_file_unlock()

void dfs_file_unlock

(

void

)

在文件 dfs.c 第 164 行定义.

{
    rt_mutex_release(&fdlock);
}

引用了 rt_mutex_release().

函数调用图:

这是这个函数的调用关系图:

dfs_init()

int dfs_init

(

void

)

this function will initialize device file system.

在文件 dfs.c 第 172 行定义.

{
    if (_dfs_init_ok)
    {
        LOG_E("DFS was already initialized.\n");
        return 0;
    }
 
    /* create device filesystem lock */
    rt_mutex_init(&fslock, "fslock", RT_IPC_FLAG_FIFO);
    rt_mutex_init(&fdlock, "fdlock", RT_IPC_FLAG_FIFO);
 
    /* clean fd table */
    dfs_dentry_init();
 
    _dfs_init_ok = RT_TRUE;
 
    return 0;
}

引用了 dfs_dentry_init(), LOG_E, RT_IPC_FLAG_FIFO, rt_mutex_init() , 以及 RT_TRUE.

函数调用图:

这是这个函数的调用关系图:

INIT_PREV_EXPORT()

INIT_PREV_EXPORT

(

dfs_init

)

引用了 dfs_init().

函数调用图:

fdt_fd_release()

void fdt_fd_release	(	struct dfs_fdtable *	fdt,
		int	fd )

在文件 dfs.c 第 248 行定义.

{
    if (fd < fdt->maxfd)
    {
        struct dfs_file *file;
 
        file = fdt_get_file(fdt, fd);
 
        if (file && file->ref_count == 1)
        {
            rt_mutex_detach(&file->pos_lock);
 
            if (file->mmap_context)
            {
                rt_free(file->mmap_context);
            }
 
            rt_free(file);
        }
        else
        {
            rt_atomic_sub(&(file->ref_count), 1);
        }
 
        fdt->fds[fd] = RT_NULL;
    }
}

引用了 dfs_fdtable::fds, fdt_get_file(), dfs_file::mmap_context, dfs_file::pos_lock, dfs_file::ref_count, rt_atomic_sub, rt_free(), rt_mutex_detach() , 以及 RT_NULL.

函数调用图:

这是这个函数的调用关系图:

fdt_fd_associate_file()

int fdt_fd_associate_file	(	struct dfs_fdtable *	fdt,
		int	fd,
		struct dfs_file *	file )

在文件 dfs.c 第 306 行定义.

{
    int retfd = -1;
 
    if (!file)
    {
        return retfd;
    }
    if (!fdt)
    {
        return retfd;
    }
 
    if (dfs_file_lock() != RT_EOK)
    {
        return -RT_ENOSYS;
    }
 
    /* check old fd */
    if ((fd < 0) || (fd >= fdt->maxfd))
    {
        goto exit;
    }
 
    if (fdt->fds[fd])
    {
        goto exit;
    }
 
    /* inc ref_count */
    rt_atomic_add(&(file->ref_count), 1);
    fdt->fds[fd] = file;
    retfd = fd;
 
exit:
    dfs_file_unlock();
    return retfd;
}

引用了 dfs_file_lock(), dfs_file_unlock(), dfs_fdtable::fds, dfs_fdtable::maxfd, dfs_file::ref_count , 以及 rt_atomic_add.

函数调用图:

fd_new()

int fd_new

(

void

)

在文件 dfs.c 第 345 行定义.

{
    struct dfs_fdtable *fdt;
 
    fdt = dfs_fdtable_get();
 
    return fdt_fd_new(fdt);
}

引用了 dfs_fdtable_get() , 以及 fdt_fd_new().

函数调用图:

这是这个函数的调用关系图:

fd_get()

struct dfs_file * fd_get

(

int

fd

)

在文件 dfs.c 第 367 行定义.

{
    struct dfs_fdtable *fdt;
 
    fdt = dfs_fdtable_get();
 
    return fdt_get_file(fdt, fd);
}

引用了 dfs_fdtable_get() , 以及 fdt_get_file().

函数调用图:

dfs_fdtable_get()

struct dfs_fdtable * dfs_fdtable_get

(

void

)

This function will get the file descriptor table of current process.

在文件 dfs.c 第 379 行定义.

{
    struct dfs_fdtable *fdt;
#ifdef RT_USING_SMART
    struct rt_lwp *lwp = NULL;
    rt_thread_t thread = rt_thread_self();
 
    if (thread)
    {
        lwp = (struct rt_lwp *)thread->lwp;
    }
 
    if (lwp)
        fdt = &lwp->fdt;
    else
        fdt = &_fdtab;
#else
    fdt = &_fdtab;
#endif
 
    return fdt;
}

引用了 rt_thread_self().

函数调用图:

这是这个函数的调用关系图:

dfs_fdtable_get_global()

struct dfs_fdtable * dfs_fdtable_get_global

(

void

)

在文件 dfs.c 第 420 行定义.

{
    return &_fdtab;
}

dfs_fdtable_dup()

int dfs_fdtable_dup	(	struct dfs_fdtable *	fdt_dst,
		struct dfs_fdtable *	fdt_src,
		int	fd_src )

Dup the specified fd_src from fdt_src to fdt_dst.

参数

fdt_dst	is the fd table for destination, if empty, use global (_fdtab).
fdt_src	is the fd table for source, if empty, use global (_fdtab).
fd_src	is the fd in the designate fdt_src table.

返回

-1 on failed or the allocated file descriptor.

在文件 dfs.c 第 436 行定义.

{
    int newfd = -1;
 
    if (dfs_file_lock() != RT_EOK)
    {
        return -RT_ENOSYS;
    }
 
    if (fdt_src == NULL)
    {
        fdt_src = &_fdtab;
    }
 
    if (fdt_dst == NULL)
    {
        fdt_dst = &_fdtab;
    }
 
    /* check fd */
    if ((fd_src < 0) || (fd_src >= fdt_src->maxfd))
    {
        goto _EXIT;
    }
    if (!fdt_src->fds[fd_src])
    {
        goto _EXIT;
    }
 
    /* get a new fd*/
    newfd = fdt_fd_new(fdt_dst);
    if (newfd >= 0)
    {
        fdt_dst->fds[newfd]->mode = fdt_src->fds[fd_src]->mode;
        fdt_dst->fds[newfd]->flags = fdt_src->fds[fd_src]->flags;
        fdt_dst->fds[newfd]->fops = fdt_src->fds[fd_src]->fops;
        fdt_dst->fds[newfd]->dentry = dfs_dentry_ref(fdt_src->fds[fd_src]->dentry);
        fdt_dst->fds[newfd]->vnode = fdt_src->fds[fd_src]->vnode;
        fdt_dst->fds[newfd]->mmap_context = RT_NULL;
        fdt_dst->fds[newfd]->data = fdt_src->fds[fd_src]->data;
 
        /*
        * dma-buf/socket fd is without dentry, so should used the vnode reference.
        */
        if (!fdt_dst->fds[newfd]->dentry)
        {
            rt_atomic_add(&(fdt_dst->fds[newfd]->vnode->ref_count), 1);
        }
    }
 
_EXIT:
    dfs_file_unlock();
 
    return newfd;
}

引用了 dfs_file::data, dfs_file::dentry, dfs_dentry_ref(), dfs_file_lock(), dfs_file_unlock(), dfs_fdtable::fds, fdt_fd_new(), dfs_file::flags, dfs_file::fops, dfs_fdtable::maxfd, dfs_file::mmap_context, dfs_file::mode, dfs_vnode::ref_count, rt_atomic_add, RT_NULL , 以及 dfs_file::vnode.

函数调用图:

dfs_fdtable_drop_fd()

int dfs_fdtable_drop_fd	(	struct dfs_fdtable *	fdt,
		int	fd )

drop fd from the fd table.

参数

fdt	is the fd table, if empty, use global (_fdtab).
fd	is the fd in the designate fd table.

返回

-1 on failed the drop file descriptor.

在文件 dfs.c 第 501 行定义.

{
    int err = 0;
 
    if (fdt == NULL)
    {
        fdt = &_fdtab;
    }
 
    if (dfs_file_lock() != RT_EOK)
    {
        return -RT_ENOSYS;
    }
 
    err = dfs_file_close(fdt->fds[fd]);
    if (!err)
    {
        fdt_fd_release(fdt, fd);
    }
 
    dfs_file_unlock();
 
    return err;
}

引用了 dfs_file_close(), dfs_file_lock(), dfs_file_unlock(), dfs_fdtable::fds , 以及 fdt_fd_release().

函数调用图:

dfs_dup()

int dfs_dup	(	int	oldfd,
		int	startfd )

在文件 dfs.c 第 526 行定义.

{
    int newfd = -1;
    struct dfs_fdtable *fdt = NULL;
 
    if (dfs_file_lock() != RT_EOK)
    {
        return -RT_ENOSYS;
    }
 
    /* check old fd */
    fdt = dfs_fdtable_get();
    if ((oldfd < 0) || (oldfd >= fdt->maxfd))
    {
        rt_set_errno(-EBADF);
        goto exit;
    }
    if (!fdt->fds[oldfd])
    {
        goto exit;
    }
    /* get a new fd */
    newfd = _fdt_slot_alloc(fdt, startfd);
    if (newfd >= 0)
    {
        fdt->fds[newfd] = fdt->fds[oldfd];
 
        /* inc ref_count */
        rt_atomic_add(&(fdt->fds[newfd]->ref_count), 1);
    }
exit:
    dfs_file_unlock();
    return newfd;
}

引用了 dfs_fdtable_get(), dfs_file_lock(), dfs_file_unlock(), dfs_fdtable::fds, dfs_fdtable::maxfd, dfs_file::ref_count , 以及 rt_atomic_add.

函数调用图:

这是这个函数的调用关系图:

dfs_dup_to()

int dfs_dup_to	(	int	oldfd,
		struct dfs_fdtable *	fdtab )

The fd in the current process dup to designate fd table.

参数

oldfd	is the fd in current process.
fdtab	is the fd table to dup, if empty, use global (_fdtab).

返回

-1 on failed or the allocated file descriptor.

在文件 dfs.c 第 570 行定义.

{
    int newfd = -1;
    struct dfs_fdtable *fdt = NULL;
 
    if (dfs_file_lock() != RT_EOK)
    {
        return -RT_ENOSYS;
    }
 
    if (fdtab == NULL)
    {
        fdtab = &_fdtab;
    }
 
    /* check old fd */
    fdt = dfs_fdtable_get();
    if ((oldfd < 0) || (oldfd >= fdt->maxfd))
    {
        goto exit;
    }
    if (!fdt->fds[oldfd])
    {
        goto exit;
    }
    /* get a new fd*/
    newfd = _fdt_slot_alloc(fdtab, DFS_STDIO_OFFSET);
    if (newfd >= 0)
    {
        fdtab->fds[newfd] = fdt->fds[oldfd];
 
        /* inc ref_count */
        rt_atomic_add(&(fdtab->fds[newfd]->ref_count), 1);
    }
exit:
    dfs_file_unlock();
 
    return newfd;
}

引用了 dfs_fdtable_get(), dfs_file_lock(), dfs_file_unlock(), DFS_STDIO_OFFSET, dfs_fdtable::fds, dfs_fdtable::maxfd, dfs_file::ref_count , 以及 rt_atomic_add.

函数调用图:

dfs_dup_from()

int dfs_dup_from	(	int	oldfd,
		struct dfs_fdtable *	fdtab )

The fd in the designate fd table dup to current process.

参数

oldfd	is the fd in the designate fd table.
fdtab	is the fd table for oldfd, if empty, use global (_fdtab).

返回

-1 on failed or the allocated file descriptor.

在文件 dfs.c 第 619 行定义.

{
    int newfd = -1;
    struct dfs_file *file;
 
    if (dfs_file_lock() != RT_EOK)
    {
        return -RT_ENOSYS;
    }
 
    if (fdtab == NULL)
    {
        fdtab = &_fdtab;
    }
 
    /* check old fd */
    if ((oldfd < 0) || (oldfd >= fdtab->maxfd))
    {
        goto exit;
    }
    if (!fdtab->fds[oldfd])
    {
        goto exit;
    }
    /* get a new fd*/
    newfd = fd_new();
    file = fd_get(newfd);
    if (newfd >= 0 && file)
    {
        file->mode = fdtab->fds[oldfd]->mode;
        file->flags = fdtab->fds[oldfd]->flags;
        file->fops = fdtab->fds[oldfd]->fops;
        file->dentry = dfs_dentry_ref(fdtab->fds[oldfd]->dentry);
        file->vnode = fdtab->fds[oldfd]->vnode;
        file->mmap_context = RT_NULL;
        file->data = fdtab->fds[oldfd]->data;
    }
 
    dfs_file_close(fdtab->fds[oldfd]);
 
exit:
    fdt_fd_release(fdtab, oldfd);
    dfs_file_unlock();
 
    return newfd;
}

引用了 dfs_file::data, dfs_file::dentry, dfs_dentry_ref(), dfs_file_close(), dfs_file_lock(), dfs_file_unlock(), fd_get(), fd_new(), dfs_fdtable::fds, fdt_fd_release(), dfs_file::flags, dfs_file::fops, dfs_fdtable::maxfd, dfs_file::mmap_context, dfs_file::mode, RT_NULL , 以及 dfs_file::vnode.

函数调用图:

sys_dup()

int sys_dup

(

int

oldfd

)

在文件 dfs.c 第 669 行定义.

{
    int err = 0;
    int newfd = dfs_dup(oldfd, (dfs_fdtable_get() == &_fdtab) ? DFS_STDIO_OFFSET : 0);
    if(newfd < 0)
    {
        err = rt_get_errno();
    }
 
#ifdef RT_USING_SMART
    return err < 0 ? err : newfd;
#else
    return err < 0 ? err : newfd;
#endif
}

引用了 dfs_dup(), dfs_fdtable_get() , 以及 DFS_STDIO_OFFSET.

函数调用图:

sys_dup2()

rt_err_t sys_dup2	(	int	oldfd,
		int	newfd )

在文件 dfs.c 第 686 行定义.

{
    struct dfs_fdtable *fdt = NULL;
    int ret = 0;
    int retfd = -1;
 
    if (dfs_file_lock() != RT_EOK)
    {
        return -RT_ENOSYS;
    }
 
    /* check old fd */
    fdt = dfs_fdtable_get();
    if ((oldfd < 0) || (oldfd >= fdt->maxfd))
    {
        goto exit;
    }
    if (!fdt->fds[oldfd])
    {
        goto exit;
    }
    if (newfd < 0)
    {
        goto exit;
    }
    if (newfd >= fdt->maxfd)
    {
        newfd = _fdt_slot_expand(fdt, newfd);
        if (newfd < 0)
        {
            goto exit;
        }
    }
    if (fdt->fds[newfd] == fdt->fds[oldfd])
    {
        /* ok, return newfd */
        retfd = newfd;
        goto exit;
    }
 
    if (fdt->fds[newfd])
    {
        ret = dfs_file_close(fdt->fds[newfd]);
        if (ret < 0)
        {
            goto exit;
        }
        fd_release(newfd);
    }
 
    fdt->fds[newfd] = fdt->fds[oldfd];
    /* inc ref_count */
    rt_atomic_add(&(fdt->fds[newfd]->ref_count), 1);
    retfd = newfd;
exit:
    dfs_file_unlock();
    return retfd;
}

引用了 dfs_fdtable_get(), dfs_file_close(), dfs_file_lock(), dfs_file_unlock(), fd_release(), dfs_fdtable::fds, dfs_fdtable::maxfd, dfs_file::ref_count , 以及 rt_atomic_add.

函数调用图:

dfs_subdir()

const char * dfs_subdir	(	const char *	directory,
		const char *	filename )

this function will return a sub-path name under directory.

参数

directory	the parent directory.
filename	the filename.

返回

the subdir pointer in filename

在文件 dfs.c 第 753 行定义.

{
    const char *dir;
 
    if (strlen(directory) == strlen(filename)) /* it's a same path */
        return NULL;
 
    dir = filename + strlen(directory);
    if ((*dir != '/') && (dir != filename))
    {
        dir--;
    }
 
    return dir;
}

这是这个函数的调用关系图:

RTM_EXPORT() [1/2]

RTM_EXPORT

(

dfs_subdir

)

引用了 dfs_subdir().

函数调用图:

dfs_normalize_path()

char * dfs_normalize_path	(	const char *	directory,
		const char *	filename )

this function will normalize a path according to specified parent directory and file name.

参数

directory	the parent path
filename	the file name

返回

the built full file path (absolute path)

在文件 dfs.c 第 779 行定义.

{
    char *fullpath;
    char *dst0, *dst, *src;
 
    /* check parameters */
    RT_ASSERT(filename != NULL);
 
#ifdef DFS_USING_WORKDIR
    if (directory == NULL) /* shall use working directory */
    {
#ifdef RT_USING_SMART
        directory = lwp_getcwd();
#else
        directory = &working_directory[0];
#endif
    }
#else
    if ((directory == NULL) && (filename[0] != '/'))
    {
        rt_kprintf(NO_WORKING_DIR);
 
        return NULL;
    }
#endif
 
    if (filename[0] != '/') /* it's a absolute path, use it directly */
    {
        int path_len;
 
        path_len = strlen(directory) + strlen(filename) + 2;
        if (path_len > DFS_PATH_MAX)
        {
            return NULL;
        }
 
        fullpath = (char *)rt_malloc(path_len);
        if (fullpath == NULL)
        {
            return NULL;
        }
 
        /* join path and file name */
        rt_snprintf(fullpath, strlen(directory) + strlen(filename) + 2,
                    "%s/%s", directory, filename);
    }
    else
    {
        fullpath = rt_strdup(filename); /* copy string */
 
        if (fullpath == NULL)
            return NULL;
    }
 
    src = fullpath;
    dst = fullpath;
 
    dst0 = dst;
    while (1)
    {
        char c = *src;
 
        if (c == '.')
        {
            if (!src[1])
                src++; /* '.' and ends */
            else if (src[1] == '/')
            {
                /* './' case */
                src += 2;
 
                while ((*src == '/') && (*src != '\0'))
                    src++;
                continue;
            }
            else if (src[1] == '.')
            {
                if (!src[2])
                {
                    /* '..' and ends case */
                    src += 2;
                    goto up_one;
                }
                else if (src[2] == '/')
                {
                    /* '../' case */
                    src += 3;
 
                    while ((*src == '/') && (*src != '\0'))
                        src++;
                    goto up_one;
                }
            }
        }
 
        /* copy up the next '/' and erase all '/' */
        while ((c = *src++) != '\0' && c != '/')
            *dst++ = c;
 
        if (c == '/')
        {
            *dst++ = '/';
            while (c == '/')
                c = *src++;
 
            src--;
        }
        else if (!c)
            break;
 
        continue;
 
    up_one:
        dst--;
        if (dst < dst0)
        {
            rt_free(fullpath);
            return NULL;
        }
        while (dst0 < dst && dst[-1] != '/')
            dst--;
    }
 
    *dst = '\0';
 
    /* remove '/' in the end of path if exist */
    dst--;
    if (dst > fullpath && (*dst == '/'))
        *dst = '\0';
 
    /* final check fullpath is not empty, for the special path of lwext "/.." */
    if ('\0' == fullpath[0])
    {
        fullpath[0] = '/';
        fullpath[1] = '\0';
    }
 
    return fullpath;
}

引用了 DFS_PATH_MAX, NO_WORKING_DIR, RT_ASSERT, rt_free(), rt_kprintf, rt_malloc() , 以及 working_directory.

函数调用图:

这是这个函数的调用关系图:

RTM_EXPORT() [2/2]

RTM_EXPORT

(

dfs_normalize_path

)

引用了 dfs_normalize_path().

函数调用图:

list_fd()

int list_fd

(

void

)

在文件 dfs.c 第 922 行定义.

{
    int index;
    struct dfs_fdtable *fd_table;
 
    fd_table = dfs_fdtable_get();
    if (!fd_table) return -1;
 
    rt_enter_critical();
 
    rt_kprintf("fd type    ref magic  path\n");
    rt_kprintf("-- ------  --- ----- ------\n");
    for (index = 0; index < (int)fd_table->maxfd; index++)
    {
        struct dfs_file *file = fd_table->fds[index];
 
        if (file && file->vnode)
        {
            rt_kprintf("%2d ", index);
            if (file->vnode->type == FT_DIRECTORY)    rt_kprintf("%-7.7s ", "dir");
            else if (file->vnode->type == FT_REGULAR) rt_kprintf("%-7.7s ", "file");
            else if (file->vnode->type == FT_SOCKET)  rt_kprintf("%-7.7s ", "socket");
            else if (file->vnode->type == FT_USER)    rt_kprintf("%-7.7s ", "user");
            else if (file->vnode->type == FT_DEVICE)  rt_kprintf("%-7.7s ", "device");
            else rt_kprintf("%-8.8s ", "unknown");
            rt_kprintf("%3d ", file->ref_count);
            rt_kprintf("%04x  ", file->magic);
 
            if (file->dentry)
            {
                rt_kprintf("%s%s\n", file->dentry->mnt->fullpath, file->dentry->pathname);
            }
            else
            {
                rt_kprintf("\n");
            }
        }
    }
    rt_exit_critical();
 
    return 0;
}

引用了 dfs_file::dentry, dfs_fdtable_get(), dfs_fdtable::fds, dfs_mnt::fullpath, dfs_file::magic, dfs_fdtable::maxfd, dfs_dentry::mnt, dfs_dentry::pathname, dfs_file::ref_count, rt_enter_critical(), rt_exit_critical(), rt_kprintf, dfs_vnode::type , 以及 dfs_file::vnode.

函数调用图:

这是这个函数的调用关系图:

MSH_CMD_EXPORT()

MSH_CMD_EXPORT	(	list_fd	,
		list file	descriptor )

引用了 list_fd().

函数调用图:

dfs_fd_dump()

int dfs_fd_dump	(	int	argc,
		char **	argv )

在文件 dfs.c 第 966 行定义.

{
    int index;
 
    if (dfs_file_lock() != RT_EOK)
    {
        return -RT_ENOSYS;
    }
 
    for (index = 0; index < _fdtab.maxfd; index++)
    {
        struct dfs_file *file = _fdtab.fds[index];
        if (file)
        {
            char* fullpath = dfs_dentry_full_path(file->dentry);
            if (fullpath)
            {
                printf("[%d] - %s, ref_count %zd\n", index,
                    fullpath, (size_t)rt_atomic_load(&(file->ref_count)));
                rt_free(fullpath);
            }
            else
            {
                printf("[%d] - %s, ref_count %zd\n", index,
                    file->dentry->pathname, (size_t)rt_atomic_load(&(file->ref_count)));
            }
        }
    }
    dfs_file_unlock();
 
    return 0;
}

引用了 dfs_file::dentry, dfs_dentry_full_path(), dfs_file_lock(), dfs_file_unlock(), dfs_dentry::pathname, dfs_file::ref_count, rt_atomic_load , 以及 rt_free().

函数调用图:

这是这个函数的调用关系图:

MSH_CMD_EXPORT_ALIAS()

MSH_CMD_EXPORT_ALIAS	(	dfs_fd_dump	,
		fd_dump	,
		fd	dump )

引用了 dfs_fd_dump().

函数调用图: