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[/] [or1k_old/] [trunk/] [uclinux/] [uClinux-2.0.x/] [fs/] [ufs/] [ufs_dir.c] - Blame information for rev 1782

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Line No. Rev Author Line
1 199 simons
/*
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 *  linux/fs/ufs/ufs_dir.c
3
 *
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 * Copyright (C) 1996
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 * Adrian Rodriguez (adrian@franklins-tower.rutgers.edu)
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 * Laboratory for Computer Science Research Computing Facility
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 * Rutgers, The State University of New Jersey
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 *
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 * $Id: ufs_dir.c,v 1.1.1.1 2001-09-10 07:44:40 simons Exp $
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 *
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 */
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#include <linux/fs.h>
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/* XXX */
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extern int ufs_lookup (struct inode *, const char *, int, struct inode **);
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extern int ufs_bmap (struct inode *, int);
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extern void ufs_print_inode (struct inode *);
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/*
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 * This is blatantly stolen from ext2fs
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 */
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static int
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ufs_readdir (struct inode * inode, struct file * filp, void * dirent,
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             filldir_t filldir)
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{
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        int error = 0;
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        unsigned long offset, lblk, blk;
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        int i, stored;
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        struct buffer_head * bh;
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        struct ufs_direct * de;
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        struct super_block * sb;
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        if (!inode || !S_ISDIR(inode->i_mode))
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                return -EBADF;
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        sb = inode->i_sb;
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        if (inode->i_sb->u.ufs_sb.s_flags & UFS_DEBUG) {
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                printk("ufs_readdir: ino %lu  f_pos %lu\n",
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                       inode->i_ino, (unsigned long) filp->f_pos);
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                ufs_print_inode(inode);
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        }
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        stored = 0;
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        bh = NULL;
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        offset = filp->f_pos & (sb->s_blocksize - 1);
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        while (!error && !stored && filp->f_pos < inode->i_size) {
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                lblk = (filp->f_pos) >> sb->s_blocksize_bits;
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                blk = ufs_bmap(inode, lblk);
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                /* XXX - ufs_bmap() call needs error checking */
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                blk = ufs_bmap(inode, lblk);
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                bh = bread (sb->s_dev, blk, sb->s_blocksize);
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                if (!bh) {
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                        /* XXX - error - skip to the next block */
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                        printk("ufs_readdir: dir inode %lu has a hole at offset %lu\n",
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                               inode->i_ino, (unsigned long int)filp->f_pos);
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                        filp->f_pos += sb->s_blocksize - offset;
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                        continue;
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                }
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revalidate:
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                /* If the dir block has changed since the last call to
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                 * readdir(2), then we might be pointing to an invalid
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                 * dirent right now.  Scan from the start of the block
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                 * to make sure. */
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                if (filp->f_version != inode->i_version) {
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                        for (i = 0; i < sb->s_blocksize && i < offset; ) {
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                                de = (struct ufs_direct *)
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                                        (bh->b_data + i);
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                                /* It's too expensive to do a full
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                                 * dirent test each time round this
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                                 * loop, but we do have to test at
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                                 * least that it is non-zero.  A
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                                 * failure will be detected in the
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                                 * dirent test below. */
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                                if (de->d_reclen < 1)
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                                        break;
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                                i += de->d_reclen;
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                        }
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                        offset = i;
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                        filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
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                                | offset;
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                        filp->f_version = inode->i_version;
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                }
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                while (!error && filp->f_pos < inode->i_size
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                       && offset < sb->s_blocksize) {
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                        de = (struct ufs_direct *) (bh->b_data + offset);
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                        /* XXX - put in a real ufs_check_dir_entry() */
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                        if ((de->d_reclen == 0) || (de->d_namlen == 0)) {
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                                filp->f_pos = (filp->f_pos & (sb->s_blocksize - 1)) + sb->s_blocksize;
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                                brelse(bh);
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                                return stored;
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                        }
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#if 0
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                        if (!ext2_check_dir_entry ("ext2_readdir", inode, de,
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                                                   bh, offset)) {
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                                /* On error, skip the f_pos to the
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                                   next block. */
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                                filp->f_pos = (filp->f_pos & (sb->s_blocksize - 1))
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                                              + sb->s_blocksize;
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                                brelse (bh);
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                                return stored;
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                        }
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#endif /* XXX */
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                        offset += de->d_reclen;
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                        if (de->d_ino) {
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                                /* We might block in the next section
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                                 * if the data destination is
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                                 * currently swapped out.  So, use a
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                                 * version stamp to detect whether or
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                                 * not the directory has been modified
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                                 * during the copy operation. */
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                                unsigned long version;
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                                dcache_add(inode, de->d_name, de->d_namlen,
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                                           de->d_ino);
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                                version = inode->i_version;
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                                if (inode->i_sb->u.ufs_sb.s_flags & UFS_DEBUG) {
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                                        printk("ufs_readdir: filldir(%s,%u)\n",
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                                               de->d_name, de->d_ino);
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                                }
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                                error = filldir(dirent, de->d_name, de->d_namlen, filp->f_pos, de->d_ino);
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                                if (error)
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                                        break;
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                                if (version != inode->i_version)
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                                        goto revalidate;
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                                stored ++;
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                        }
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                        filp->f_pos += de->d_reclen;
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                }
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                offset = 0;
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                brelse (bh);
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        }
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#if 0 /* XXX */
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        if (!IS_RDONLY(inode)) {
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                inode->i_atime = CURRENT_TIME;
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                inode->i_dirt = 1;
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        }
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#endif /* XXX */
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        return 0;
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}
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static struct file_operations ufs_dir_operations = {
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        NULL,                   /* lseek */
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        NULL,                   /* read */
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        NULL,                   /* write */
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        ufs_readdir,            /* readdir */
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        NULL,                   /* select */
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        NULL,                   /* ioctl */
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        NULL,                   /* mmap */
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        NULL,                   /* open */
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        NULL,                   /* release */
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        file_fsync,             /* fsync */
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        NULL,                   /* fasync */
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        NULL,                   /* check_media_change */
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        NULL,                   /* revalidate */
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};
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struct inode_operations ufs_dir_inode_operations = {
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        &ufs_dir_operations,    /* default directory file operations */
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        NULL,                   /* create */
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        ufs_lookup,             /* lookup */
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        NULL,                   /* link */
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        NULL,                   /* unlink */
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        NULL,                   /* symlink */
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        NULL,                   /* mkdir */
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        NULL,                   /* rmdir */
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        NULL,                   /* mknod */
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        NULL,                   /* rename */
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        NULL,                   /* readlink */
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        NULL,                   /* follow_link */
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        NULL,                   /* readpage */
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        NULL,                   /* writepage */
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        NULL,                   /* bmap */
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        NULL,                   /* truncate */
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        NULL,                   /* permission */
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        NULL,                   /* smap */
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};
180
 
181
/*
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 * Local Variables: ***
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 * c-indent-level: 8 ***
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 * c-continued-statement-offset: 8 ***
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 * c-brace-offset: -8 ***
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 * c-argdecl-indent: 0 ***
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 * c-label-offset: -8 ***
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 * End: ***
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 */

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