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1628 |
jcastillo |
/*
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* linux/fs/sysv/dir.c
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*
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* minix/dir.c
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* coh/dir.c
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* Copyright (C) 1993 Pascal Haible, Bruno Haible
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*
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* sysv/dir.c
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* Copyright (C) 1993 Bruno Haible
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*
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* SystemV/Coherent directory handling functions
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*/
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/sysv_fs.h>
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#include <linux/stat.h>
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#include <linux/string.h>
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#include <asm/segment.h>
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static int sysv_dir_read(struct inode * inode, struct file * filp, char * buf, int count)
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{
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return -EISDIR;
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}
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static int sysv_readdir(struct inode *, struct file *, void *, filldir_t);
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static struct file_operations sysv_dir_operations = {
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NULL, /* lseek - default */
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sysv_dir_read, /* read */
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NULL, /* write - bad */
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sysv_readdir, /* readdir */
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NULL, /* select - default */
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NULL, /* ioctl - default */
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NULL, /* mmap */
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NULL, /* no special open code */
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NULL, /* no special release code */
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file_fsync /* default fsync */
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};
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/*
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* directories can handle most operations...
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*/
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struct inode_operations sysv_dir_inode_operations = {
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&sysv_dir_operations, /* default directory file-ops */
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sysv_create, /* create */
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sysv_lookup, /* lookup */
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sysv_link, /* link */
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sysv_unlink, /* unlink */
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sysv_symlink, /* symlink */
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sysv_mkdir, /* mkdir */
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sysv_rmdir, /* rmdir */
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sysv_mknod, /* mknod */
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sysv_rename, /* 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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sysv_truncate, /* truncate */
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NULL /* permission */
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};
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static int sysv_readdir(struct inode * inode, struct file * filp,
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void * dirent, filldir_t filldir)
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{
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struct super_block * sb;
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unsigned int offset,i;
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struct buffer_head * bh;
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char* bh_data;
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struct sysv_dir_entry * de, sde;
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if (!inode || !(sb = inode->i_sb) || !S_ISDIR(inode->i_mode))
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return -EBADF;
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if ((unsigned long)(filp->f_pos) % SYSV_DIRSIZE)
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return -EBADF;
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while (filp->f_pos < inode->i_size) {
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offset = filp->f_pos & sb->sv_block_size_1;
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bh = sysv_file_bread(inode, filp->f_pos >> sb->sv_block_size_bits, 0);
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if (!bh) {
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filp->f_pos += sb->sv_block_size - offset;
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continue;
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}
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bh_data = bh->b_data;
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while (offset < sb->sv_block_size && filp->f_pos < inode->i_size) {
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de = (struct sysv_dir_entry *) (offset + bh_data);
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if (de->inode) {
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/* Copy the directory entry first, because the directory
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* might be modified while we sleep in filldir()...
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*/
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memcpy(&sde, de, sizeof(struct sysv_dir_entry));
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if (sde.inode > inode->i_sb->sv_ninodes)
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printk("sysv_readdir: Bad inode number on dev "
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"%s, ino %ld, offset 0x%04lx: %d is out of range\n",
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kdevname(inode->i_dev),
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inode->i_ino, (off_t) filp->f_pos, sde.inode);
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i = strnlen(sde.name, SYSV_NAMELEN);
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if (filldir(dirent, sde.name, i, filp->f_pos, sde.inode) < 0) {
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brelse(bh);
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return 0;
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}
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}
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offset += SYSV_DIRSIZE;
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filp->f_pos += SYSV_DIRSIZE;
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}
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brelse(bh);
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}
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return 0;
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}
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