Subversion Repositories or1k

/*

 * dir.c

 *

 * Copyright (c) 1999 Al Smith

 */

#include <linux/efs_fs.h>

static int efs_readdir(struct file *, void *, filldir_t);

struct file_operations efs_dir_operations = {

        read:           generic_read_dir,

        readdir:        efs_readdir,

};

struct inode_operations efs_dir_inode_operations = {

        lookup:         efs_lookup,

};

static int efs_readdir(struct file *filp, void *dirent, filldir_t filldir) {

        struct inode *inode = filp->f_dentry->d_inode;

        struct buffer_head *bh;

        struct efs_dir          *dirblock;

        struct efs_dentry       *dirslot;

        efs_ino_t               inodenum;

        efs_block_t             block;

        int                     slot, namelen;

        char                    *nameptr;

        if (inode->i_size & (EFS_DIRBSIZE-1))

                printk(KERN_WARNING "EFS: WARNING: readdir(): directory size not a multiple of EFS_DIRBSIZE\n");

        /* work out where this entry can be found */

        block = filp->f_pos >> EFS_DIRBSIZE_BITS;

        /* each block contains at most 256 slots */

        slot  = filp->f_pos & 0xff;

        /* look at all blocks */

        while (block < inode->i_blocks) {

                /* read the dir block */

                bh = sb_bread(inode->i_sb, efs_bmap(inode, block));

                if (!bh) {

                        printk(KERN_ERR "EFS: readdir(): failed to read dir block %d\n", block);

                        break;

                }

                dirblock = (struct efs_dir *) bh->b_data;

                if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {

                        printk(KERN_ERR "EFS: readdir(): invalid directory block\n");

                        brelse(bh);

                        break;

                }

                while (slot < dirblock->slots) {

                        if (dirblock->space[slot] == 0) {

                                slot++;

                                continue;

                        }

                        dirslot  = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot));

                        inodenum = be32_to_cpu(dirslot->inode);

                        namelen  = dirslot->namelen;

                        nameptr  = dirslot->name;

#ifdef DEBUG

                        printk(KERN_DEBUG "EFS: readdir(): block %d slot %d/%d: inode %u, name \"%s\", namelen %u\n", block, slot, dirblock->slots-1, inodenum, nameptr, namelen);

#endif

                        if (namelen > 0) {

                                /* found the next entry */

                                filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;

                                /* copy filename and data in dirslot */

                                filldir(dirent, nameptr, namelen, filp->f_pos, inodenum, DT_UNKNOWN);

                                /* sanity check */

                                if (nameptr - (char *) dirblock + namelen > EFS_DIRBSIZE) {

                                        printk(KERN_WARNING "EFS: directory entry %d exceeds directory block\n", slot);

                                        slot++;

                                        continue;

                                }

                                /* store position of next slot */

                                if (++slot == dirblock->slots) {

                                        slot = 0;

                                        block++;

                                }

                                brelse(bh);

                                filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;

                                return 0;

                        }

                        slot++;

                }

                brelse(bh);

                slot = 0;

                block++;

        }

        filp->f_pos = (block << EFS_DIRBSIZE_BITS) | slot;

        return 0;

}