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/*

 *  linux/fs/affs/dir.c

 *

 *  (c) 1996  Hans-Joachim Widmaier - Rewritten

 *

 *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.

 *

 *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.

 *

 *  (C) 1991  Linus Torvalds - minix filesystem

 *

 *  affs directory handling functions

 *

 */

#include "affs.h"

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

const struct file_operations affs_dir_operations = {

        .read           = generic_read_dir,

        .readdir        = affs_readdir,

        .fsync          = file_fsync,

};

/*

 * directories can handle most operations...

 */

const struct inode_operations affs_dir_inode_operations = {

        .create         = affs_create,

        .lookup         = affs_lookup,

        .link           = affs_link,

        .unlink         = affs_unlink,

        .symlink        = affs_symlink,

        .mkdir          = affs_mkdir,

        .rmdir          = affs_rmdir,

        .rename         = affs_rename,

        .setattr        = affs_notify_change,

};

static int

affs_readdir(struct file *filp, void *dirent, filldir_t filldir)

{

        struct inode            *inode = filp->f_path.dentry->d_inode;

        struct super_block      *sb = inode->i_sb;

        struct buffer_head      *dir_bh;

        struct buffer_head      *fh_bh;

        unsigned char           *name;

        int                      namelen;

        u32                      i;

        int                      hash_pos;

        int                      chain_pos;

        u32                      f_pos;

        u32                      ino;

        int                      stored;

        int                      res;

        pr_debug("AFFS: readdir(ino=%lu,f_pos=%lx)\n",inode->i_ino,(unsigned long)filp->f_pos);

        stored = 0;

        res    = -EIO;

        dir_bh = NULL;

        fh_bh  = NULL;

        f_pos  = filp->f_pos;

        if (f_pos == 0) {

                filp->private_data = (void *)0;

                if (filldir(dirent, ".", 1, f_pos, inode->i_ino, DT_DIR) < 0)

                        return 0;

                filp->f_pos = f_pos = 1;

                stored++;

        }

        if (f_pos == 1) {

                if (filldir(dirent, "..", 2, f_pos, parent_ino(filp->f_path.dentry), DT_DIR) < 0)

                        return stored;

                filp->f_pos = f_pos = 2;

                stored++;

        }

        affs_lock_dir(inode);

        chain_pos = (f_pos - 2) & 0xffff;

        hash_pos  = (f_pos - 2) >> 16;

        if (chain_pos == 0xffff) {

                affs_warning(sb, "readdir", "More than 65535 entries in chain");

                chain_pos = 0;

                hash_pos++;

                filp->f_pos = ((hash_pos << 16) | chain_pos) + 2;

        }

        dir_bh = affs_bread(sb, inode->i_ino);

        if (!dir_bh)

                goto readdir_out;

        /* If the directory hasn't changed since the last call to readdir(),

         * we can jump directly to where we left off.

         */

        ino = (u32)(long)filp->private_data;

        if (ino && filp->f_version == inode->i_version) {

                pr_debug("AFFS: readdir() left off=%d\n", ino);

                goto inside;

        }

        ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);

        for (i = 0; ino && i < chain_pos; i++) {

                fh_bh = affs_bread(sb, ino);

                if (!fh_bh) {

                        affs_error(sb, "readdir","Cannot read block %d", i);

                        goto readdir_out;

                }

                ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);

                affs_brelse(fh_bh);

                fh_bh = NULL;

        }

        if (ino)

                goto inside;

        hash_pos++;

        for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) {

                ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);

                if (!ino)

                        continue;

                f_pos = (hash_pos << 16) + 2;

inside:

                do {

                        fh_bh = affs_bread(sb, ino);

                        if (!fh_bh) {

                                affs_error(sb, "readdir","Cannot read block %d", ino);

                                goto readdir_done;

                        }

                        namelen = min(AFFS_TAIL(sb, fh_bh)->name[0], (u8)30);

                        name = AFFS_TAIL(sb, fh_bh)->name + 1;

                        pr_debug("AFFS: readdir(): filldir(\"%.*s\", ino=%u), hash=%d, f_pos=%x\n",

                                 namelen, name, ino, hash_pos, f_pos);

                        if (filldir(dirent, name, namelen, f_pos, ino, DT_UNKNOWN) < 0)

                                goto readdir_done;

                        stored++;

                        f_pos++;

                        ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);

                        affs_brelse(fh_bh);

                        fh_bh = NULL;

                } while (ino);

        }

readdir_done:

        filp->f_pos = f_pos;

        filp->f_version = inode->i_version;

        filp->private_data = (void *)(long)ino;

        res = stored;

readdir_out:

        affs_brelse(dir_bh);

        affs_brelse(fh_bh);

        affs_unlock_dir(inode);

        pr_debug("AFFS: readdir()=%d\n", stored);

        return res;

}