source: rtems/cpukit/libfs/src/jffs2/src/dir-rtems.c @ 3c96bee

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2001-2003 Free Software Foundation, Inc.
 * Copyright © 2001-2007 Red Hat, Inc.
 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
 * Copyright © 2013 embedded brains GmbH <rtems@embedded-brains.de>
 *
 * Created by David Woodhouse <dwmw2@cambridge.redhat.com>
 *
 * Port to the RTEMS by embedded brains GmbH.
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 * $Id: dir-ecos.c,v 1.11 2005/02/08 19:36:27 lunn Exp $
 *
 */

#include <linux/kernel.h>
#include <linux/crc32.h>
#include "nodelist.h"

/***********************************************************************/

/* Takes length argument because it can be either NUL-terminated or '/'-terminated */
struct _inode *jffs2_lookup(struct _inode *dir_i, const unsigned char *name, size_t namelen)
{
        struct jffs2_inode_info *dir_f;
        struct jffs2_full_dirent *fd = NULL, *fd_list;
        uint32_t ino = 0;
        uint32_t hash = full_name_hash(name, namelen);
        struct _inode *inode = NULL;

        D1(printk("jffs2_lookup()\n"));

        dir_f = JFFS2_INODE_INFO(dir_i);

        mutex_lock(&dir_f->sem);

        /* NB: The 2.2 backport will need to explicitly check for '.' and '..' here */
        for (fd_list = dir_f->dents; fd_list && fd_list->nhash <= hash; fd_list = fd_list->next) {
                if (fd_list->nhash == hash && 
                    (!fd || fd_list->version > fd->version) &&
                    strlen((char *)fd_list->name) == namelen &&
                    !strncmp((char *)fd_list->name, (char *)name, namelen)) {
                        fd = fd_list;
                }
        }
        if (fd)
                ino = fd->ino;
        mutex_unlock(&dir_f->sem);
        if (ino) {
                inode = jffs2_iget(dir_i->i_sb, ino);
                if (IS_ERR(inode)) {
                        printk("jffs2_iget() failed for ino #%u\n", ino);
                        return inode;
                } else {
                        inode->i_fd = fd;
                }
        }

        return inode;
}

/***********************************************************************/



int jffs2_create(struct _inode *dir_i, const char *d_name, size_t d_namelen, int mode)
{
        struct jffs2_raw_inode *ri;
        struct jffs2_inode_info *f, *dir_f;
        struct jffs2_sb_info *c;
        struct _inode *inode;
        int ret;
        struct qstr qstr;

        qstr.name = d_name;
        qstr.len = d_namelen;

        ri = jffs2_alloc_raw_inode();
        if (!ri)
                return -ENOMEM;
        
        c = JFFS2_SB_INFO(dir_i->i_sb);

        D1(printk(KERN_DEBUG "jffs2_create()\n"));

        inode = jffs2_new_inode(dir_i, mode, ri);

        if (IS_ERR(inode)) {
                D1(printk(KERN_DEBUG "jffs2_new_inode() failed\n"));
                jffs2_free_raw_inode(ri);
                return PTR_ERR(inode);
        }

        f = JFFS2_INODE_INFO(inode);
        dir_f = JFFS2_INODE_INFO(dir_i);

        ret = jffs2_do_create(c, dir_f, f, ri, &qstr);

        if (ret) {
                inode->i_nlink = 0;
                jffs2_iput(inode);
                jffs2_free_raw_inode(ri);
                return ret;
        }

        dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(ri->ctime));

        jffs2_free_raw_inode(ri);

        D1(printk(KERN_DEBUG "jffs2_create: Created ino #%lu with mode %o, nlink %d(%d)\n",
                  inode->i_ino, inode->i_mode, inode->i_nlink, f->inocache->pino_nlink));
        jffs2_iput(inode);
        return 0;
}

/***********************************************************************/


int jffs2_unlink(struct _inode *dir_i, struct _inode *d_inode, const unsigned char *d_name, size_t d_namelen)
{
        struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
        struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
        struct jffs2_inode_info *dead_f = JFFS2_INODE_INFO(d_inode);
        int ret;

        ret = jffs2_do_unlink(c, dir_f, (const char *)d_name,
                               d_namelen, dead_f, get_seconds());
        if (dead_f->inocache)
                d_inode->i_nlink = dead_f->inocache->pino_nlink;
        return ret;
}
/***********************************************************************/


int jffs2_link (struct _inode *old_d_inode, struct _inode *dir_i, const unsigned char *d_name, size_t d_namelen)
{
        struct jffs2_sb_info *c = JFFS2_SB_INFO(old_d_inode->i_sb);
        struct jffs2_inode_info *f = JFFS2_INODE_INFO(old_d_inode);
        struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
        int ret;

        /* XXX: This is ugly */
        uint8_t type = (old_d_inode->i_mode & S_IFMT) >> 12;
        if (!type) type = DT_REG;

        ret = jffs2_do_link(c, dir_f, f->inocache->ino, type, 
                            (const char * )d_name, 
                            d_namelen, get_seconds());

        if (!ret) {
                mutex_lock(&f->sem);
                old_d_inode->i_nlink = ++f->inocache->pino_nlink;
                mutex_unlock(&f->sem);
        }
        return ret;
}

/***********************************************************************/

int jffs2_mknod(
        struct _inode *dir_i,
        const unsigned char *d_name,
        size_t d_namelen,
        int mode,
        const unsigned char *data,
        size_t datalen
)
{
        struct jffs2_inode_info *f, *dir_f;
        struct jffs2_sb_info *c;
        struct _inode *inode;
        struct jffs2_raw_inode *ri;
        struct jffs2_raw_dirent *rd;
        struct jffs2_full_dnode *fn;
        struct jffs2_full_dirent *fd;
        uint32_t alloclen;
        int ret;

        /* FIXME: If you care. We'd need to use frags for the data
           if it grows much more than this */
        if (datalen > 254)
                return -ENAMETOOLONG;

        ri = jffs2_alloc_raw_inode();

        if (!ri)
                return -ENOMEM;

        c = JFFS2_SB_INFO(dir_i->i_sb);

        /* Try to reserve enough space for both node and dirent.
         * Just the node will do for now, though
         */
        ret = jffs2_reserve_space(c, sizeof(*ri) + datalen, &alloclen,
                                  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);

        if (ret) {
                jffs2_free_raw_inode(ri);
                return ret;
        }

        inode = jffs2_new_inode(dir_i, mode, ri);

        if (IS_ERR(inode)) {
                jffs2_free_raw_inode(ri);
                jffs2_complete_reservation(c);
                return PTR_ERR(inode);
        }

        f = JFFS2_INODE_INFO(inode);

        inode->i_size = datalen;
        ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size);
        ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size);
        ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));

        ri->compr = JFFS2_COMPR_NONE;
        ri->data_crc = cpu_to_je32(crc32(0, data, datalen));
        ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));

        fn = jffs2_write_dnode(c, f, ri, data, datalen, ALLOC_NORMAL);

        jffs2_free_raw_inode(ri);

        if (IS_ERR(fn)) {
                /* Eeek. Wave bye bye */
                mutex_unlock(&f->sem);
                jffs2_complete_reservation(c);
                ret = PTR_ERR(fn);
                goto fail;
        }

        if (S_ISLNK(mode)) {
                /* We use f->target field to store the target path. */
                f->target = kmemdup(data, datalen + 1, GFP_KERNEL);
                if (!f->target) {
                        pr_warn("Can't allocate %d bytes of memory\n", datalen + 1);
                        mutex_unlock(&f->sem);
                        jffs2_complete_reservation(c);
                        ret = -ENOMEM;
                        goto fail;
                }

                jffs2_dbg(1, "%s(): symlink's target '%s' cached\n",
                          __func__, (char *)f->target);
        }

        /* No data here. Only a metadata node, which will be
           obsoleted by the first data write
        */
        f->metadata = fn;
        mutex_unlock(&f->sem);

        jffs2_complete_reservation(c);

        ret = jffs2_reserve_space(c, sizeof(*rd)+d_namelen, &alloclen,
                                  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(d_namelen));
        if (ret)
                goto fail;

        rd = jffs2_alloc_raw_dirent();
        if (!rd) {
                /* Argh. Now we treat it like a normal delete */
                jffs2_complete_reservation(c);
                ret = -ENOMEM;
                goto fail;
        }

        dir_f = JFFS2_INODE_INFO(dir_i);
        mutex_lock(&dir_f->sem);

        rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
        rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
        rd->totlen = cpu_to_je32(sizeof(*rd) + d_namelen);
        rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));

        rd->pino = cpu_to_je32(dir_i->i_ino);
        rd->version = cpu_to_je32(++dir_f->highest_version);
        rd->ino = cpu_to_je32(inode->i_ino);
        rd->mctime = cpu_to_je32(get_seconds());
        rd->nsize = d_namelen;

        /* XXX: This is ugly. */
        rd->type = (mode & S_IFMT) >> 12;

        rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
        rd->name_crc = cpu_to_je32(crc32(0, d_name, d_namelen));

        fd = jffs2_write_dirent(c, dir_f, rd, d_name, d_namelen, ALLOC_NORMAL);

        if (IS_ERR(fd)) {
                /* dirent failed to write. Delete the inode normally
                   as if it were the final unlink() */
                jffs2_complete_reservation(c);
                jffs2_free_raw_dirent(rd);
                mutex_unlock(&dir_f->sem);
                ret = PTR_ERR(fd);
                goto fail;
        }

        dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));

        jffs2_free_raw_dirent(rd);

        /* Link the fd into the inode's list, obsoleting an old
           one if necessary. */
        jffs2_add_fd_to_list(c, fd, &dir_f->dents);

        mutex_unlock(&dir_f->sem);
        jffs2_complete_reservation(c);

 fail:
        jffs2_iput(inode);

        return ret;
}

int jffs2_rmdir (struct _inode *dir_i, struct _inode *d_inode, const unsigned char *d_name, size_t d_namelen)
{
        struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode);
        struct jffs2_full_dirent *fd;

        for (fd = f->dents ; fd; fd = fd->next) {
                if (fd->ino)
                        return -ENOTEMPTY;
        }
        return jffs2_unlink(dir_i, d_inode, d_name, d_namelen);
}

int jffs2_rename (struct _inode *old_dir_i, struct _inode *d_inode, const unsigned char *old_d_name, size_t old_d_namelen,
                  struct _inode *new_dir_i, const unsigned char *new_d_name, size_t new_d_namelen)
{
        int ret;
        struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
        struct jffs2_inode_info *victim_f = NULL;
        uint8_t type;
        uint32_t now;

#if 0 /* FIXME -- this really doesn't belong in individual file systems. 
         The fileio code ought to do this for us, or at least part of it */
        if (new_dentry->d_inode) {
                if (S_ISDIR(d_inode->i_mode) && 
                    !S_ISDIR(new_dentry->d_inode->i_mode)) {
                        /* Cannot rename directory over non-directory */
                        return -EINVAL;
                }

                victim_f = JFFS2_INODE_INFO(new_dentry->d_inode);

                if (S_ISDIR(new_dentry->d_inode->i_mode)) {
                        struct jffs2_full_dirent *fd;

                        if (!S_ISDIR(d_inode->i_mode)) {
                                /* Cannot rename non-directory over directory */
                                return -EINVAL;
                        }
                        mutex_lock(&victim_f->sem);
                        for (fd = victim_f->dents; fd; fd = fd->next) {
                                if (fd->ino) {
                                        mutex_unlock(&victim_f->sem);
                                        return -ENOTEMPTY;
                                }
                        }
                        mutex_unlock(&victim_f->sem);
                }
        }
#endif

        /* XXX: We probably ought to alloc enough space for
           both nodes at the same time. Writing the new link, 
           then getting -ENOSPC, is quite bad :)
        */

        /* Make a hard link */
        
        /* XXX: This is ugly */
        type = (d_inode->i_mode & S_IFMT) >> 12;
        if (!type) type = DT_REG;

        now = get_seconds();
        ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i),
                            d_inode->i_ino, type,
                            (const char *)new_d_name,
                            new_d_namelen, now);

        if (ret)
                return ret;

        if (victim_f) {
                /* There was a victim. Kill it off nicely */
                /* Don't oops if the victim was a dirent pointing to an
                   inode which didn't exist. */
                if (victim_f->inocache) {
                        mutex_lock(&victim_f->sem);
                        victim_f->inocache->pino_nlink--;
                        mutex_unlock(&victim_f->sem);
                }
        }

        /* Unlink the original */
        ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
                              (const char *)old_d_name,
                              old_d_namelen, NULL, now);

        if (ret) {
                /* Oh shit. We really ought to make a single node which can do both atomically */
                struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode);
                mutex_lock(&f->sem);
                if (f->inocache)
                        d_inode->i_nlink = f->inocache->pino_nlink++;
                mutex_unlock(&f->sem);

                printk(KERN_NOTICE "jffs2_rename(): Link succeeded, unlink failed (err %d). You now have a hard link\n", ret);
        }
        return ret;
}