linux-imx

/*

 *  fs/libfs.c

 *  Library for filesystems writers.

 */

​

#include <linux/blkdev.h>

#include <linux/export.h>

#include <linux/pagemap.h>

#include <linux/slab.h>

#include <linux/cred.h>

#include <linux/mount.h>

#include <linux/vfs.h>

#include <linux/quotaops.h>

#include <linux/mutex.h>

#include <linux/namei.h>

#include <linux/exportfs.h>

#include <linux/writeback.h>

#include <linux/buffer_head.h> /* sync_mapping_buffers */

​

#include <linux/uaccess.h>

​

#include "internal.h"

​

int simple_getattr(const struct path *path, struct kstat *stat,

           u32 request_mask, unsigned int query_flags)

{

    struct inode *inode = d_inode(path->dentry);

    generic_fillattr(inode, stat);

    stat->blocks = inode->i_mapping->nrpages << (PAGE_SHIFT - 9);

    return 0;

}

EXPORT_SYMBOL(simple_getattr);

​

int simple_statfs(struct dentry *dentry, struct kstatfs *buf)

{

    buf->f_type = dentry->d_sb->s_magic;

    buf->f_bsize = PAGE_SIZE;

    buf->f_namelen = NAME_MAX;

    return 0;

}

EXPORT_SYMBOL(simple_statfs);

​

/*

 * Retaining negative dentries for an in-memory filesystem just wastes

 * memory and lookup time: arrange for them to be deleted immediately.

 */

int always_delete_dentry(const struct dentry *dentry)

{

    return 1;

}

EXPORT_SYMBOL(always_delete_dentry);

​

const struct dentry_operations simple_dentry_operations = {

    .d_delete = always_delete_dentry,

};

EXPORT_SYMBOL(simple_dentry_operations);

​

/*

 * Lookup the data. This is trivial - if the dentry didn't already

 * exist, we know it is negative.  Set d_op to delete negative dentries.

 */

struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)

{