Ejemplo n.º 1
0
static int gfs2_atomic_open(struct inode *dir, struct dentry *dentry,
                            struct file *file, unsigned flags,
                            umode_t mode, int *opened)
{
	struct dentry *d;
	bool excl = !!(flags & O_EXCL);

	d = __gfs2_lookup(dir, dentry, file, opened);
	if (IS_ERR(d))
		return PTR_ERR(d);
	if (d != NULL)
		dentry = d;
	if (dentry->d_inode) {
		if (!(*opened & FILE_OPENED)) {
			if (d == NULL)
				dget(dentry);
			return finish_no_open(file, dentry);
		}
		dput(d);
		return 0;
	}

	BUG_ON(d != NULL);
	if (!(flags & O_CREAT))
		return -ENOENT;

	return gfs2_create_inode(dir, dentry, file, S_IFREG | mode, 0, NULL, 0, excl, opened);
}
Ejemplo n.º 2
0
static int gfs2_atomic_open(struct inode *dir, struct dentry *dentry,
			    struct file *file, unsigned flags,
			    umode_t mode)
{
	struct dentry *d;
	bool excl = !!(flags & O_EXCL);

	if (!d_in_lookup(dentry))
		goto skip_lookup;

	d = __gfs2_lookup(dir, dentry, file);
	if (IS_ERR(d))
		return PTR_ERR(d);
	if (d != NULL)
		dentry = d;
	if (d_really_is_positive(dentry)) {
		if (!(file->f_mode & FMODE_OPENED))
			return finish_no_open(file, d);
		dput(d);
		return 0;
	}

	BUG_ON(d != NULL);

skip_lookup:
	if (!(flags & O_CREAT))
		return -ENOENT;

	return gfs2_create_inode(dir, dentry, file, S_IFREG | mode, 0, NULL, 0, excl);
}
Ejemplo n.º 3
0
static int gfs2_symlink(struct inode *dir, struct dentry *dentry,
			const char *symname)
{
	struct gfs2_sbd *sdp = GFS2_SB(dir);
	unsigned int size;

	size = strlen(symname);
	if (size > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode) - 1)
		return -ENAMETOOLONG;

	return gfs2_create_inode(dir, dentry, NULL, S_IFLNK | S_IRWXUGO, 0, symname, size, 0, NULL);
}
Ejemplo n.º 4
0
static int link_dinode(struct gfs2_inode *dip, const struct qstr *name,
		       struct gfs2_inode *ip, struct gfs2_diradd *da)
{
	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
	struct gfs2_alloc_parms ap = { .target = da->nr_blocks, };
	int error;

	if (da->nr_blocks) {
		error = gfs2_quota_lock_check(dip);
		if (error)
			goto fail_quota_locks;

		error = gfs2_inplace_reserve(dip, &ap);
		if (error)
			goto fail_quota_locks;

		error = gfs2_trans_begin(sdp, gfs2_trans_da_blks(dip, da, 2), 0);
		if (error)
			goto fail_ipreserv;
	} else {
		error = gfs2_trans_begin(sdp, RES_LEAF + 2 * RES_DINODE, 0);
		if (error)
			goto fail_quota_locks;
	}

	error = gfs2_dir_add(&dip->i_inode, name, ip, da);
	if (error)
		goto fail_end_trans;

fail_end_trans:
	gfs2_trans_end(sdp);
fail_ipreserv:
	gfs2_inplace_release(dip);
fail_quota_locks:
	gfs2_quota_unlock(dip);
	return error;
}

static int gfs2_initxattrs(struct inode *inode, const struct xattr *xattr_array,
		    void *fs_info)
{
	const struct xattr *xattr;
	int err = 0;

	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
		err = __gfs2_xattr_set(inode, xattr->name, xattr->value,
				       xattr->value_len, 0,
				       GFS2_EATYPE_SECURITY);
		if (err < 0)
			break;
	}
	return err;
}

static int gfs2_security_init(struct gfs2_inode *dip, struct gfs2_inode *ip,
			      const struct qstr *qstr)
{
	return security_inode_init_security(&ip->i_inode, &dip->i_inode, qstr,
					    &gfs2_initxattrs, NULL);
}

/**
 * gfs2_create_inode - Create a new inode
 * @dir: The parent directory
 * @dentry: The new dentry
 * @file: If non-NULL, the file which is being opened
 * @mode: The permissions on the new inode
 * @dev: For device nodes, this is the device number
 * @symname: For symlinks, this is the link destination
 * @size: The initial size of the inode (ignored for directories)
 *
 * Returns: 0 on success, or error code
 */

static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
			     struct file *file,
			     umode_t mode, dev_t dev, const char *symname,
			     unsigned int size, int excl, int *opened)
{
	const struct qstr *name = &dentry->d_name;
	struct posix_acl *default_acl, *acl;
	struct gfs2_holder ghs[2];
	struct inode *inode = NULL;
	struct gfs2_inode *dip = GFS2_I(dir), *ip;
	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
	struct gfs2_glock *io_gl;
	struct dentry *d;
	int error;
	u32 aflags = 0;
	struct gfs2_diradd da = { .bh = NULL, };

	if (!name->len || name->len > GFS2_FNAMESIZE)
		return -ENAMETOOLONG;

	error = gfs2_rs_alloc(dip);
	if (error)
		return error;

	error = gfs2_rindex_update(sdp);
	if (error)
		return error;

	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
	if (error)
		goto fail;

	error = create_ok(dip, name, mode);
	if (error)
		goto fail_gunlock;

	inode = gfs2_dir_search(dir, &dentry->d_name, !S_ISREG(mode) || excl);
	error = PTR_ERR(inode);
	if (!IS_ERR(inode)) {
		d = d_splice_alias(inode, dentry);
		error = PTR_ERR(d);
		if (IS_ERR(d)) {
			inode = ERR_CAST(d);
			goto fail_gunlock;
		}
		error = 0;
		if (file) {
			if (S_ISREG(inode->i_mode)) {
				WARN_ON(d != NULL);
				error = finish_open(file, dentry, gfs2_open_common, opened);
			} else {
				error = finish_no_open(file, d);
			}
		} else {
			dput(d);
		}
		gfs2_glock_dq_uninit(ghs);
		return error;
	} else if (error != -ENOENT) {
		goto fail_gunlock;
	}

	error = gfs2_diradd_alloc_required(dir, name, &da);
	if (error < 0)
		goto fail_gunlock;

	inode = new_inode(sdp->sd_vfs);
	error = -ENOMEM;
	if (!inode)
		goto fail_gunlock;

	error = posix_acl_create(dir, &mode, &default_acl, &acl);
	if (error)
		goto fail_free_vfs_inode;

	ip = GFS2_I(inode);
	error = gfs2_rs_alloc(ip);
	if (error)
		goto fail_free_acls;

	inode->i_mode = mode;
	set_nlink(inode, S_ISDIR(mode) ? 2 : 1);
	inode->i_rdev = dev;
	inode->i_size = size;
	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	gfs2_set_inode_blocks(inode, 1);
	munge_mode_uid_gid(dip, inode);
	ip->i_goal = dip->i_goal;
	ip->i_diskflags = 0;
	ip->i_eattr = 0;
	ip->i_height = 0;
	ip->i_depth = 0;
	ip->i_entries = 0;

	switch(mode & S_IFMT) {
	case S_IFREG:
		if ((dip->i_diskflags & GFS2_DIF_INHERIT_JDATA) ||
		    gfs2_tune_get(sdp, gt_new_files_jdata))
			ip->i_diskflags |= GFS2_DIF_JDATA;
		gfs2_set_aops(inode);
		break;
	case S_IFDIR:
		ip->i_diskflags |= (dip->i_diskflags & GFS2_DIF_INHERIT_JDATA);
		ip->i_diskflags |= GFS2_DIF_JDATA;
		ip->i_entries = 2;
		break;
	}
	gfs2_set_inode_flags(inode);

	if ((GFS2_I(sdp->sd_root_dir->d_inode) == dip) ||
	    (dip->i_diskflags & GFS2_DIF_TOPDIR))
		aflags |= GFS2_AF_ORLOV;

	error = alloc_dinode(ip, aflags);
	if (error)
		goto fail_free_inode;

	error = gfs2_glock_get(sdp, ip->i_no_addr, &gfs2_inode_glops, CREATE, &ip->i_gl);
	if (error)
		goto fail_free_inode;

	ip->i_gl->gl_object = ip;
	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, ghs + 1);
	if (error)
		goto fail_free_inode;

	error = gfs2_trans_begin(sdp, RES_DINODE, 0);
	if (error)
		goto fail_gunlock2;

	init_dinode(dip, ip, symname);
	gfs2_trans_end(sdp);

	error = gfs2_glock_get(sdp, ip->i_no_addr, &gfs2_iopen_glops, CREATE, &io_gl);
	if (error)
		goto fail_gunlock2;

	error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, GL_EXACT, &ip->i_iopen_gh);
	if (error)
		goto fail_gunlock2;

	ip->i_iopen_gh.gh_gl->gl_object = ip;
	gfs2_glock_put(io_gl);
	gfs2_set_iop(inode);
	insert_inode_hash(inode);

	if (default_acl) {
		error = gfs2_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
		posix_acl_release(default_acl);
	}
	if (acl) {
		if (!error)
			error = gfs2_set_acl(inode, acl, ACL_TYPE_ACCESS);
		posix_acl_release(acl);
	}

	if (error)
		goto fail_gunlock3;

	error = gfs2_security_init(dip, ip, name);
	if (error)
		goto fail_gunlock3;

	error = link_dinode(dip, name, ip, &da);
	if (error)
		goto fail_gunlock3;

	mark_inode_dirty(inode);
	d_instantiate(dentry, inode);
	if (file) {
		*opened |= FILE_CREATED;
		error = finish_open(file, dentry, gfs2_open_common, opened);
	}
	gfs2_glock_dq_uninit(ghs);
	gfs2_glock_dq_uninit(ghs + 1);
	return error;

fail_gunlock3:
	gfs2_glock_dq_uninit(ghs + 1);
	if (ip->i_gl)
		gfs2_glock_put(ip->i_gl);
	goto fail_gunlock;

fail_gunlock2:
	gfs2_glock_dq_uninit(ghs + 1);
fail_free_inode:
	if (ip->i_gl)
		gfs2_glock_put(ip->i_gl);
	gfs2_rs_delete(ip, NULL);
fail_free_acls:
	if (default_acl)
		posix_acl_release(default_acl);
	if (acl)
		posix_acl_release(acl);
fail_free_vfs_inode:
	free_inode_nonrcu(inode);
	inode = NULL;
fail_gunlock:
	gfs2_dir_no_add(&da);
	gfs2_glock_dq_uninit(ghs);
	if (inode && !IS_ERR(inode)) {
		clear_nlink(inode);
		mark_inode_dirty(inode);
		set_bit(GIF_ALLOC_FAILED, &GFS2_I(inode)->i_flags);
		iput(inode);
	}
fail:
	return error;
}

/**
 * gfs2_create - Create a file
 * @dir: The directory in which to create the file
 * @dentry: The dentry of the new file
 * @mode: The mode of the new file
 *
 * Returns: errno
 */

static int gfs2_create(struct inode *dir, struct dentry *dentry,
		       umode_t mode, bool excl)
{
	return gfs2_create_inode(dir, dentry, NULL, S_IFREG | mode, 0, NULL, 0, excl, NULL);
}

/**
 * __gfs2_lookup - Look up a filename in a directory and return its inode
 * @dir: The directory inode
 * @dentry: The dentry of the new inode
 * @file: File to be opened
 * @opened: atomic_open flags
 *
 *
 * Returns: errno
 */

static struct dentry *__gfs2_lookup(struct inode *dir, struct dentry *dentry,
				    struct file *file, int *opened)
{
	struct inode *inode;
	struct dentry *d;
	struct gfs2_holder gh;
	struct gfs2_glock *gl;
	int error;

	inode = gfs2_lookupi(dir, &dentry->d_name, 0);
	if (!inode)
		return NULL;
	if (IS_ERR(inode))
		return ERR_CAST(inode);

	gl = GFS2_I(inode)->i_gl;
	error = gfs2_glock_nq_init(gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
	if (error) {
		iput(inode);
		return ERR_PTR(error);
	}

	d = d_splice_alias(inode, dentry);
	if (IS_ERR(d)) {
		gfs2_glock_dq_uninit(&gh);
		return d;
	}
	if (file && S_ISREG(inode->i_mode))
		error = finish_open(file, dentry, gfs2_open_common, opened);

	gfs2_glock_dq_uninit(&gh);
	if (error) {
		dput(d);
		return ERR_PTR(error);
	}
	return d;
}

static struct dentry *gfs2_lookup(struct inode *dir, struct dentry *dentry,
				  unsigned flags)
{
	return __gfs2_lookup(dir, dentry, NULL, NULL);
}

/**
 * gfs2_link - Link to a file
 * @old_dentry: The inode to link
 * @dir: Add link to this directory
 * @dentry: The name of the link
 *
 * Link the inode in "old_dentry" into the directory "dir" with the
 * name in "dentry".
 *
 * Returns: errno
 */

static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
		     struct dentry *dentry)
{
	struct gfs2_inode *dip = GFS2_I(dir);
	struct gfs2_sbd *sdp = GFS2_SB(dir);
	struct inode *inode = old_dentry->d_inode;
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_holder ghs[2];
	struct buffer_head *dibh;
	struct gfs2_diradd da = { .bh = NULL, };
	int error;

	if (S_ISDIR(inode->i_mode))
		return -EPERM;

	error = gfs2_rs_alloc(dip);
	if (error)
		return error;

	gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1);

	error = gfs2_glock_nq(ghs); /* parent */
	if (error)
		goto out_parent;

	error = gfs2_glock_nq(ghs + 1); /* child */
	if (error)
		goto out_child;

	error = -ENOENT;
	if (inode->i_nlink == 0)
		goto out_gunlock;

	error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC);
	if (error)
		goto out_gunlock;

	error = gfs2_dir_check(dir, &dentry->d_name, NULL);
	switch (error) {
	case -ENOENT:
		break;
	case 0:
		error = -EEXIST;
	default:
		goto out_gunlock;
	}

	error = -EINVAL;
	if (!dip->i_inode.i_nlink)
		goto out_gunlock;
	error = -EFBIG;
	if (dip->i_entries == (u32)-1)
		goto out_gunlock;
	error = -EPERM;
	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
		goto out_gunlock;
	error = -EINVAL;
	if (!ip->i_inode.i_nlink)
		goto out_gunlock;
	error = -EMLINK;
	if (ip->i_inode.i_nlink == (u32)-1)
		goto out_gunlock;

	error = gfs2_diradd_alloc_required(dir, &dentry->d_name, &da);
	if (error < 0)
		goto out_gunlock;

	if (da.nr_blocks) {
		struct gfs2_alloc_parms ap = { .target = da.nr_blocks, };
		error = gfs2_quota_lock_check(dip);
		if (error)
			goto out_gunlock;

		error = gfs2_inplace_reserve(dip, &ap);
		if (error)
			goto out_gunlock_q;

		error = gfs2_trans_begin(sdp, gfs2_trans_da_blks(dip, &da, 2), 0);
		if (error)
			goto out_ipres;
	} else {
		error = gfs2_trans_begin(sdp, 2 * RES_DINODE + RES_LEAF, 0);
		if (error)
			goto out_ipres;
	}

	error = gfs2_meta_inode_buffer(ip, &dibh);
	if (error)
		goto out_end_trans;

	error = gfs2_dir_add(dir, &dentry->d_name, ip, &da);
	if (error)
		goto out_brelse;

	gfs2_trans_add_meta(ip->i_gl, dibh);
	inc_nlink(&ip->i_inode);
	ip->i_inode.i_ctime = CURRENT_TIME;
	ihold(inode);
	d_instantiate(dentry, inode);
	mark_inode_dirty(inode);

out_brelse:
	brelse(dibh);
out_end_trans:
	gfs2_trans_end(sdp);
out_ipres:
	if (da.nr_blocks)
		gfs2_inplace_release(dip);
out_gunlock_q:
	if (da.nr_blocks)
		gfs2_quota_unlock(dip);
out_gunlock:
	gfs2_dir_no_add(&da);
	gfs2_glock_dq(ghs + 1);
out_child:
	gfs2_glock_dq(ghs);
out_parent:
	gfs2_holder_uninit(ghs);
	gfs2_holder_uninit(ghs + 1);
	return error;
}

/*
 * gfs2_unlink_ok - check to see that a inode is still in a directory
 * @dip: the directory
 * @name: the name of the file
 * @ip: the inode
 *
 * Assumes that the lock on (at least) @dip is held.
 *
 * Returns: 0 if the parent/child relationship is correct, errno if it isn't
 */

static int gfs2_unlink_ok(struct gfs2_inode *dip, const struct qstr *name,
			  const struct gfs2_inode *ip)
{
	int error;

	if (IS_IMMUTABLE(&ip->i_inode) || IS_APPEND(&ip->i_inode))
		return -EPERM;

	if ((dip->i_inode.i_mode & S_ISVTX) &&
	    !uid_eq(dip->i_inode.i_uid, current_fsuid()) &&
	    !uid_eq(ip->i_inode.i_uid, current_fsuid()) && !capable(CAP_FOWNER))
		return -EPERM;

	if (IS_APPEND(&dip->i_inode))
		return -EPERM;

	error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC);
	if (error)
		return error;

	error = gfs2_dir_check(&dip->i_inode, name, ip);
	if (error)
		return error;

	return 0;
}
Ejemplo n.º 5
0
static int gfs2_mknod(struct inode *dir, struct dentry *dentry, umode_t mode,
		      dev_t dev)
{
	return gfs2_create_inode(dir, dentry, NULL, mode, dev, NULL, 0, 0, NULL);
}
Ejemplo n.º 6
0
static int gfs2_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	struct gfs2_sbd *sdp = GFS2_SB(dir);
	unsigned dsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode);
	return gfs2_create_inode(dir, dentry, NULL, S_IFDIR | mode, 0, NULL, dsize, 0, NULL);
}
Ejemplo n.º 7
0
static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
			     umode_t mode, dev_t dev, const char *symname,
			     unsigned int size, int excl)
{
	const struct qstr *name = &dentry->d_name;
	struct gfs2_holder ghs[2];
	struct inode *inode = NULL;
	struct gfs2_inode *dip = GFS2_I(dir);
	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
	struct gfs2_inum_host inum = { .no_addr = 0, .no_formal_ino = 0 };
	int error;
	u64 generation;
	struct buffer_head *bh = NULL;

	if (!name->len || name->len > GFS2_FNAMESIZE)
		return -ENAMETOOLONG;

	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
	if (error)
		goto fail;

	error = create_ok(dip, name, mode);
	if ((error == -EEXIST) && S_ISREG(mode) && !excl) {
		inode = gfs2_lookupi(dir, &dentry->d_name, 0);
		gfs2_glock_dq_uninit(ghs);
		d_instantiate(dentry, inode);
		return IS_ERR(inode) ? PTR_ERR(inode) : 0;
	}
	if (error)
		goto fail_gunlock;

	error = alloc_dinode(dip, &inum.no_addr, &generation);
	if (error)
		goto fail_gunlock;
	inum.no_formal_ino = generation;

	error = gfs2_glock_nq_num(sdp, inum.no_addr, &gfs2_inode_glops,
				  LM_ST_EXCLUSIVE, GL_SKIP, ghs + 1);
	if (error)
		goto fail_gunlock;

	error = make_dinode(dip, ghs[1].gh_gl, mode, &inum, &generation, dev, symname, size, &bh);
	if (error)
		goto fail_gunlock2;

	inode = gfs2_inode_lookup(dir->i_sb, IF2DT(mode), inum.no_addr,
				  inum.no_formal_ino, 0);
	if (IS_ERR(inode))
		goto fail_gunlock2;

	error = gfs2_inode_refresh(GFS2_I(inode));
	if (error)
		goto fail_gunlock2;

	error = gfs2_acl_create(dip, inode);
	if (error)
		goto fail_gunlock2;

	error = gfs2_security_init(dip, GFS2_I(inode), name);
	if (error)
		goto fail_gunlock2;

	error = link_dinode(dip, name, GFS2_I(inode));
	if (error)
		goto fail_gunlock2;

	if (bh)
		brelse(bh);

	gfs2_trans_end(sdp);
	/* Check if we reserved space in the rgrp. Function link_dinode may
	   not, depending on whether alloc is required. */
	if (dip->i_res)
		gfs2_inplace_release(dip);
	gfs2_quota_unlock(dip);
	gfs2_qadata_put(dip);
	mark_inode_dirty(inode);
	gfs2_glock_dq_uninit_m(2, ghs);
	d_instantiate(dentry, inode);
	return 0;

fail_gunlock2:
	gfs2_glock_dq_uninit(ghs + 1);
fail_gunlock:
	gfs2_glock_dq_uninit(ghs);
	if (inode && !IS_ERR(inode)) {
		set_bit(GIF_ALLOC_FAILED, &GFS2_I(inode)->i_flags);
		iput(inode);
	}
fail:
	if (bh)
		brelse(bh);
	return error;
}

/**
 * gfs2_create - Create a file
 * @dir: The directory in which to create the file
 * @dentry: The dentry of the new file
 * @mode: The mode of the new file
 *
 * Returns: errno
 */

static int gfs2_create(struct inode *dir, struct dentry *dentry,
		       umode_t mode, struct nameidata *nd)
{
	int excl = 0;
	if (nd && (nd->flags & LOOKUP_EXCL))
		excl = 1;
	return gfs2_create_inode(dir, dentry, S_IFREG | mode, 0, NULL, 0, excl);
}
Ejemplo n.º 8
0
static int gfs2_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	return gfs2_create_inode(dir, dentry, S_IFDIR | mode, 0, NULL, 0, 0);
}
Ejemplo n.º 9
0
static int gfs2_create(struct inode *dir, struct dentry *dentry,
		       umode_t mode, bool excl)
{
	return gfs2_create_inode(dir, dentry, S_IFREG | mode, 0, NULL, 0, excl);
}
Ejemplo n.º 10
0
static int link_dinode(struct gfs2_inode *dip, const struct qstr *name,
		       struct gfs2_inode *ip, struct gfs2_diradd *da)
{
	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
	struct gfs2_alloc_parms ap = { .target = da->nr_blocks, };
	int error;

	if (da->nr_blocks) {
		error = gfs2_quota_lock_check(dip, &ap);
		if (error)
			goto fail_quota_locks;

		error = gfs2_inplace_reserve(dip, &ap);
		if (error)
			goto fail_quota_locks;

		error = gfs2_trans_begin(sdp, gfs2_trans_da_blks(dip, da, 2), 0);
		if (error)
			goto fail_ipreserv;
	} else {
		error = gfs2_trans_begin(sdp, RES_LEAF + 2 * RES_DINODE, 0);
		if (error)
			goto fail_quota_locks;
	}

	error = gfs2_dir_add(&dip->i_inode, name, ip, da);

	gfs2_trans_end(sdp);
fail_ipreserv:
	gfs2_inplace_release(dip);
fail_quota_locks:
	gfs2_quota_unlock(dip);
	return error;
}

static int gfs2_initxattrs(struct inode *inode, const struct xattr *xattr_array,
		    void *fs_info)
{
	const struct xattr *xattr;
	int err = 0;

	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
		err = __gfs2_xattr_set(inode, xattr->name, xattr->value,
				       xattr->value_len, 0,
				       GFS2_EATYPE_SECURITY);
		if (err < 0)
			break;
	}
	return err;
}

/**
 * gfs2_create_inode - Create a new inode
 * @dir: The parent directory
 * @dentry: The new dentry
 * @file: If non-NULL, the file which is being opened
 * @mode: The permissions on the new inode
 * @dev: For device nodes, this is the device number
 * @symname: For symlinks, this is the link destination
 * @size: The initial size of the inode (ignored for directories)
 *
 * Returns: 0 on success, or error code
 */

static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
			     struct file *file,
			     umode_t mode, dev_t dev, const char *symname,
			     unsigned int size, int excl)
{
	const struct qstr *name = &dentry->d_name;
	struct posix_acl *default_acl, *acl;
	struct gfs2_holder ghs[2];
	struct inode *inode = NULL;
	struct gfs2_inode *dip = GFS2_I(dir), *ip;
	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
	struct gfs2_glock *io_gl = NULL;
	int error, free_vfs_inode = 1;
	u32 aflags = 0;
	unsigned blocks = 1;
	struct gfs2_diradd da = { .bh = NULL, .save_loc = 1, };

	if (!name->len || name->len > GFS2_FNAMESIZE)
		return -ENAMETOOLONG;

	error = gfs2_rsqa_alloc(dip);
	if (error)
		return error;

	error = gfs2_rindex_update(sdp);
	if (error)
		return error;

	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
	if (error)
		goto fail;
	gfs2_holder_mark_uninitialized(ghs + 1);

	error = create_ok(dip, name, mode);
	if (error)
		goto fail_gunlock;

	inode = gfs2_dir_search(dir, &dentry->d_name, !S_ISREG(mode) || excl);
	error = PTR_ERR(inode);
	if (!IS_ERR(inode)) {
		if (S_ISDIR(inode->i_mode)) {
			iput(inode);
			inode = ERR_PTR(-EISDIR);
			goto fail_gunlock;
		}
		d_instantiate(dentry, inode);
		error = 0;
		if (file) {
			if (S_ISREG(inode->i_mode))
				error = finish_open(file, dentry, gfs2_open_common);
			else
				error = finish_no_open(file, NULL);
		}
		gfs2_glock_dq_uninit(ghs);
		return error;
	} else if (error != -ENOENT) {
		goto fail_gunlock;
	}

	error = gfs2_diradd_alloc_required(dir, name, &da);
	if (error < 0)
		goto fail_gunlock;

	inode = new_inode(sdp->sd_vfs);
	error = -ENOMEM;
	if (!inode)
		goto fail_gunlock;

	error = posix_acl_create(dir, &mode, &default_acl, &acl);
	if (error)
		goto fail_gunlock;

	ip = GFS2_I(inode);
	error = gfs2_rsqa_alloc(ip);
	if (error)
		goto fail_free_acls;

	inode->i_mode = mode;
	set_nlink(inode, S_ISDIR(mode) ? 2 : 1);
	inode->i_rdev = dev;
	inode->i_size = size;
	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
	gfs2_set_inode_blocks(inode, 1);
	munge_mode_uid_gid(dip, inode);
	check_and_update_goal(dip);
	ip->i_goal = dip->i_goal;
	ip->i_diskflags = 0;
	ip->i_eattr = 0;
	ip->i_height = 0;
	ip->i_depth = 0;
	ip->i_entries = 0;
	ip->i_no_addr = 0; /* Temporarily zero until real addr is assigned */

	switch(mode & S_IFMT) {
	case S_IFREG:
		if ((dip->i_diskflags & GFS2_DIF_INHERIT_JDATA) ||
		    gfs2_tune_get(sdp, gt_new_files_jdata))
			ip->i_diskflags |= GFS2_DIF_JDATA;
		gfs2_set_aops(inode);
		break;
	case S_IFDIR:
		ip->i_diskflags |= (dip->i_diskflags & GFS2_DIF_INHERIT_JDATA);
		ip->i_diskflags |= GFS2_DIF_JDATA;
		ip->i_entries = 2;
		break;
	}

	/* Force SYSTEM flag on all files and subdirs of a SYSTEM directory */
	if (dip->i_diskflags & GFS2_DIF_SYSTEM)
		ip->i_diskflags |= GFS2_DIF_SYSTEM;

	gfs2_set_inode_flags(inode);

	if ((GFS2_I(d_inode(sdp->sd_root_dir)) == dip) ||
	    (dip->i_diskflags & GFS2_DIF_TOPDIR))
		aflags |= GFS2_AF_ORLOV;

	if (default_acl || acl)
		blocks++;

	error = alloc_dinode(ip, aflags, &blocks);
	if (error)
		goto fail_free_inode;

	gfs2_set_inode_blocks(inode, blocks);

	error = gfs2_glock_get(sdp, ip->i_no_addr, &gfs2_inode_glops, CREATE, &ip->i_gl);
	if (error)
		goto fail_free_inode;
	flush_delayed_work(&ip->i_gl->gl_work);
	glock_set_object(ip->i_gl, ip);

	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, ghs + 1);
	if (error)
		goto fail_free_inode;

	error = gfs2_trans_begin(sdp, blocks, 0);
	if (error)
		goto fail_gunlock2;

	if (blocks > 1) {
		ip->i_eattr = ip->i_no_addr + 1;
		gfs2_init_xattr(ip);
	}
	init_dinode(dip, ip, symname);
	gfs2_trans_end(sdp);

	error = gfs2_glock_get(sdp, ip->i_no_addr, &gfs2_iopen_glops, CREATE, &io_gl);
	if (error)
		goto fail_gunlock2;

	BUG_ON(test_and_set_bit(GLF_INODE_CREATING, &io_gl->gl_flags));

	error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, GL_EXACT, &ip->i_iopen_gh);
	if (error)
		goto fail_gunlock2;

	glock_set_object(ip->i_iopen_gh.gh_gl, ip);
	gfs2_glock_put(io_gl);
	gfs2_set_iop(inode);
	insert_inode_hash(inode);

	free_vfs_inode = 0; /* After this point, the inode is no longer
			       considered free. Any failures need to undo
			       the gfs2 structures. */
	if (default_acl) {
		error = __gfs2_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
		if (error)
			goto fail_gunlock3;
		posix_acl_release(default_acl);
		default_acl = NULL;
	}
	if (acl) {
		error = __gfs2_set_acl(inode, acl, ACL_TYPE_ACCESS);
		if (error)
			goto fail_gunlock3;
		posix_acl_release(acl);
		acl = NULL;
	}

	error = security_inode_init_security(&ip->i_inode, &dip->i_inode, name,
					     &gfs2_initxattrs, NULL);
	if (error)
		goto fail_gunlock3;

	error = link_dinode(dip, name, ip, &da);
	if (error)
		goto fail_gunlock3;

	mark_inode_dirty(inode);
	d_instantiate(dentry, inode);
	if (file) {
		file->f_mode |= FMODE_CREATED;
		error = finish_open(file, dentry, gfs2_open_common);
	}
	gfs2_glock_dq_uninit(ghs);
	gfs2_glock_dq_uninit(ghs + 1);
	clear_bit(GLF_INODE_CREATING, &io_gl->gl_flags);
	return error;

fail_gunlock3:
	glock_clear_object(io_gl, ip);
	gfs2_glock_dq_uninit(&ip->i_iopen_gh);
	gfs2_glock_put(io_gl);
fail_gunlock2:
	if (io_gl)
		clear_bit(GLF_INODE_CREATING, &io_gl->gl_flags);
fail_free_inode:
	if (ip->i_gl) {
		glock_clear_object(ip->i_gl, ip);
		gfs2_glock_put(ip->i_gl);
	}
	gfs2_rsqa_delete(ip, NULL);
fail_free_acls:
	posix_acl_release(default_acl);
	posix_acl_release(acl);
fail_gunlock:
	gfs2_dir_no_add(&da);
	gfs2_glock_dq_uninit(ghs);
	if (inode && !IS_ERR(inode)) {
		clear_nlink(inode);
		if (!free_vfs_inode)
			mark_inode_dirty(inode);
		set_bit(free_vfs_inode ? GIF_FREE_VFS_INODE : GIF_ALLOC_FAILED,
			&GFS2_I(inode)->i_flags);
		iput(inode);
	}
	if (gfs2_holder_initialized(ghs + 1))
		gfs2_glock_dq_uninit(ghs + 1);
fail:
	return error;
}

/**
 * gfs2_create - Create a file
 * @dir: The directory in which to create the file
 * @dentry: The dentry of the new file
 * @mode: The mode of the new file
 *
 * Returns: errno
 */

static int gfs2_create(struct inode *dir, struct dentry *dentry,
		       umode_t mode, bool excl)
{
	return gfs2_create_inode(dir, dentry, NULL, S_IFREG | mode, 0, NULL, 0, excl);
}

/**
 * __gfs2_lookup - Look up a filename in a directory and return its inode
 * @dir: The directory inode
 * @dentry: The dentry of the new inode
 * @file: File to be opened
 *
 *
 * Returns: errno
 */

static struct dentry *__gfs2_lookup(struct inode *dir, struct dentry *dentry,
				    struct file *file)
{
	struct inode *inode;
	struct dentry *d;
	struct gfs2_holder gh;
	struct gfs2_glock *gl;
	int error;

	inode = gfs2_lookupi(dir, &dentry->d_name, 0);
	if (inode == NULL) {
		d_add(dentry, NULL);
		return NULL;
	}
	if (IS_ERR(inode))
		return ERR_CAST(inode);

	gl = GFS2_I(inode)->i_gl;
	error = gfs2_glock_nq_init(gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
	if (error) {
		iput(inode);
		return ERR_PTR(error);
	}

	d = d_splice_alias(inode, dentry);
	if (IS_ERR(d)) {
		gfs2_glock_dq_uninit(&gh);
		return d;
	}
	if (file && S_ISREG(inode->i_mode))
		error = finish_open(file, dentry, gfs2_open_common);

	gfs2_glock_dq_uninit(&gh);
	if (error) {
		dput(d);
		return ERR_PTR(error);
	}
	return d;
}

static struct dentry *gfs2_lookup(struct inode *dir, struct dentry *dentry,
				  unsigned flags)
{
	return __gfs2_lookup(dir, dentry, NULL);
}

/**
 * gfs2_link - Link to a file
 * @old_dentry: The inode to link
 * @dir: Add link to this directory
 * @dentry: The name of the link
 *
 * Link the inode in "old_dentry" into the directory "dir" with the
 * name in "dentry".
 *
 * Returns: errno
 */

static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
		     struct dentry *dentry)
{
	struct gfs2_inode *dip = GFS2_I(dir);
	struct gfs2_sbd *sdp = GFS2_SB(dir);
	struct inode *inode = d_inode(old_dentry);
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_holder ghs[2];
	struct buffer_head *dibh;
	struct gfs2_diradd da = { .bh = NULL, .save_loc = 1, };
	int error;

	if (S_ISDIR(inode->i_mode))
		return -EPERM;

	error = gfs2_rsqa_alloc(dip);
	if (error)
		return error;

	gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1);

	error = gfs2_glock_nq(ghs); /* parent */
	if (error)
		goto out_parent;

	error = gfs2_glock_nq(ghs + 1); /* child */
	if (error)
		goto out_child;

	error = -ENOENT;
	if (inode->i_nlink == 0)
		goto out_gunlock;

	error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC);
	if (error)
		goto out_gunlock;

	error = gfs2_dir_check(dir, &dentry->d_name, NULL);
	switch (error) {
	case -ENOENT:
		break;
	case 0:
		error = -EEXIST;
	default:
		goto out_gunlock;
	}

	error = -EINVAL;
	if (!dip->i_inode.i_nlink)
		goto out_gunlock;
	error = -EFBIG;
	if (dip->i_entries == (u32)-1)
		goto out_gunlock;
	error = -EPERM;
	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
		goto out_gunlock;
	error = -EINVAL;
	if (!ip->i_inode.i_nlink)
		goto out_gunlock;
	error = -EMLINK;
	if (ip->i_inode.i_nlink == (u32)-1)
		goto out_gunlock;

	error = gfs2_diradd_alloc_required(dir, &dentry->d_name, &da);
	if (error < 0)
		goto out_gunlock;

	if (da.nr_blocks) {
		struct gfs2_alloc_parms ap = { .target = da.nr_blocks, };
		error = gfs2_quota_lock_check(dip, &ap);
		if (error)
			goto out_gunlock;

		error = gfs2_inplace_reserve(dip, &ap);
		if (error)
			goto out_gunlock_q;

		error = gfs2_trans_begin(sdp, gfs2_trans_da_blks(dip, &da, 2), 0);
		if (error)
			goto out_ipres;
	} else {
		error = gfs2_trans_begin(sdp, 2 * RES_DINODE + RES_LEAF, 0);
		if (error)
			goto out_ipres;
	}

	error = gfs2_meta_inode_buffer(ip, &dibh);
	if (error)
		goto out_end_trans;

	error = gfs2_dir_add(dir, &dentry->d_name, ip, &da);
	if (error)
		goto out_brelse;

	gfs2_trans_add_meta(ip->i_gl, dibh);
	inc_nlink(&ip->i_inode);
	ip->i_inode.i_ctime = current_time(&ip->i_inode);
	ihold(inode);
	d_instantiate(dentry, inode);
	mark_inode_dirty(inode);

out_brelse:
	brelse(dibh);
out_end_trans:
	gfs2_trans_end(sdp);
out_ipres:
	if (da.nr_blocks)
		gfs2_inplace_release(dip);
out_gunlock_q:
	if (da.nr_blocks)
		gfs2_quota_unlock(dip);
out_gunlock:
	gfs2_dir_no_add(&da);
	gfs2_glock_dq(ghs + 1);
out_child:
	gfs2_glock_dq(ghs);
out_parent:
	gfs2_holder_uninit(ghs);
	gfs2_holder_uninit(ghs + 1);
	return error;
}

/*
 * gfs2_unlink_ok - check to see that a inode is still in a directory
 * @dip: the directory
 * @name: the name of the file
 * @ip: the inode
 *
 * Assumes that the lock on (at least) @dip is held.
 *
 * Returns: 0 if the parent/child relationship is correct, errno if it isn't
 */

static int gfs2_unlink_ok(struct gfs2_inode *dip, const struct qstr *name,
			  const struct gfs2_inode *ip)
{
	int error;

	if (IS_IMMUTABLE(&ip->i_inode) || IS_APPEND(&ip->i_inode))
		return -EPERM;

	if ((dip->i_inode.i_mode & S_ISVTX) &&
	    !uid_eq(dip->i_inode.i_uid, current_fsuid()) &&
	    !uid_eq(ip->i_inode.i_uid, current_fsuid()) && !capable(CAP_FOWNER))
		return -EPERM;

	if (IS_APPEND(&dip->i_inode))
		return -EPERM;

	error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC);
	if (error)
		return error;

	return gfs2_dir_check(&dip->i_inode, name, ip);
}

/**
 * gfs2_unlink_inode - Removes an inode from its parent dir and unlinks it
 * @dip: The parent directory
 * @name: The name of the entry in the parent directory
 * @inode: The inode to be removed
 *
 * Called with all the locks and in a transaction. This will only be
 * called for a directory after it has been checked to ensure it is empty.
 *
 * Returns: 0 on success, or an error
 */

static int gfs2_unlink_inode(struct gfs2_inode *dip,
			     const struct dentry *dentry)
{
	struct inode *inode = d_inode(dentry);
	struct gfs2_inode *ip = GFS2_I(inode);
	int error;

	error = gfs2_dir_del(dip, dentry);
	if (error)
		return error;

	ip->i_entries = 0;
	inode->i_ctime = current_time(inode);
	if (S_ISDIR(inode->i_mode))
		clear_nlink(inode);
	else
		drop_nlink(inode);
	mark_inode_dirty(inode);
	if (inode->i_nlink == 0)
		gfs2_unlink_di(inode);
	return 0;
}


/**
 * gfs2_unlink - Unlink an inode (this does rmdir as well)
 * @dir: The inode of the directory containing the inode to unlink
 * @dentry: The file itself
 *
 * This routine uses the type of the inode as a flag to figure out
 * whether this is an unlink or an rmdir.
 *
 * Returns: errno
 */

static int gfs2_unlink(struct inode *dir, struct dentry *dentry)
{
	struct gfs2_inode *dip = GFS2_I(dir);
	struct gfs2_sbd *sdp = GFS2_SB(dir);
	struct inode *inode = d_inode(dentry);
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_holder ghs[3];
	struct gfs2_rgrpd *rgd;
	int error;

	error = gfs2_rindex_update(sdp);
	if (error)
		return error;

	error = -EROFS;

	gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
	gfs2_holder_init(ip->i_gl,  LM_ST_EXCLUSIVE, 0, ghs + 1);

	rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr, 1);
	if (!rgd)
		goto out_inodes;

	gfs2_holder_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, ghs + 2);


	error = gfs2_glock_nq(ghs); /* parent */
	if (error)
		goto out_parent;

	error = gfs2_glock_nq(ghs + 1); /* child */
	if (error)
		goto out_child;

	error = -ENOENT;
	if (inode->i_nlink == 0)
		goto out_rgrp;

	if (S_ISDIR(inode->i_mode)) {
		error = -ENOTEMPTY;
		if (ip->i_entries > 2 || inode->i_nlink > 2)
			goto out_rgrp;
	}

	error = gfs2_glock_nq(ghs + 2); /* rgrp */
	if (error)
		goto out_rgrp;

	error = gfs2_unlink_ok(dip, &dentry->d_name, ip);
	if (error)
		goto out_gunlock;

	error = gfs2_trans_begin(sdp, 2*RES_DINODE + 3*RES_LEAF + RES_RG_BIT, 0);
	if (error)
		goto out_gunlock;

	error = gfs2_unlink_inode(dip, dentry);
	gfs2_trans_end(sdp);

out_gunlock:
	gfs2_glock_dq(ghs + 2);
out_rgrp:
	gfs2_glock_dq(ghs + 1);
out_child:
	gfs2_glock_dq(ghs);
out_parent:
	gfs2_holder_uninit(ghs + 2);
out_inodes:
	gfs2_holder_uninit(ghs + 1);
	gfs2_holder_uninit(ghs);
	return error;
}

/**
 * gfs2_symlink - Create a symlink
 * @dir: The directory to create the symlink in
 * @dentry: The dentry to put the symlink in
 * @symname: The thing which the link points to
 *
 * Returns: errno
 */

static int gfs2_symlink(struct inode *dir, struct dentry *dentry,
			const char *symname)
{
	unsigned int size;

	size = strlen(symname);
	if (size >= gfs2_max_stuffed_size(GFS2_I(dir)))
		return -ENAMETOOLONG;

	return gfs2_create_inode(dir, dentry, NULL, S_IFLNK | S_IRWXUGO, 0, symname, size, 0);
}

/**
 * gfs2_mkdir - Make a directory
 * @dir: The parent directory of the new one
 * @dentry: The dentry of the new directory
 * @mode: The mode of the new directory
 *
 * Returns: errno
 */

static int gfs2_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	unsigned dsize = gfs2_max_stuffed_size(GFS2_I(dir));
	return gfs2_create_inode(dir, dentry, NULL, S_IFDIR | mode, 0, NULL, dsize, 0);
}
Ejemplo n.º 11
0
static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
			     unsigned int mode, dev_t dev, const char *symname,
			     unsigned int size)
{
	const struct qstr *name = &dentry->d_name;
	struct gfs2_holder ghs[2];
	struct inode *inode = NULL;
	struct gfs2_inode *dip = GFS2_I(dir);
	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
	struct gfs2_inum_host inum = { .no_addr = 0, .no_formal_ino = 0 };
	int error;
	u64 generation;
	struct buffer_head *bh = NULL;

	if (!name->len || name->len > GFS2_FNAMESIZE)
		return -ENAMETOOLONG;

	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
	if (error)
		goto fail;

	error = create_ok(dip, name, mode);
	if (error)
		goto fail_gunlock;

	error = alloc_dinode(dip, &inum.no_addr, &generation);
	if (error)
		goto fail_gunlock;
	inum.no_formal_ino = generation;

	error = gfs2_glock_nq_num(sdp, inum.no_addr, &gfs2_inode_glops,
				  LM_ST_EXCLUSIVE, GL_SKIP, ghs + 1);
	if (error)
		goto fail_gunlock;

	error = make_dinode(dip, ghs[1].gh_gl, mode, &inum, &generation, dev, symname, size, &bh);
	if (error)
		goto fail_gunlock2;

	inode = gfs2_inode_lookup(dir->i_sb, IF2DT(mode), inum.no_addr,
				  inum.no_formal_ino, 0);
	if (IS_ERR(inode))
		goto fail_gunlock2;

	error = gfs2_inode_refresh(GFS2_I(inode));
	if (error)
		goto fail_gunlock2;

	error = gfs2_acl_create(dip, inode);
	if (error)
		goto fail_gunlock2;

	error = gfs2_security_init(dip, GFS2_I(inode), name);
	if (error)
		goto fail_gunlock2;

	error = link_dinode(dip, name, GFS2_I(inode));
	if (error)
		goto fail_gunlock2;

	if (bh)
		brelse(bh);

	gfs2_trans_end(sdp);
	if (dip->i_alloc->al_rgd)
		gfs2_inplace_release(dip);
	gfs2_quota_unlock(dip);
	gfs2_alloc_put(dip);
	gfs2_glock_dq_uninit_m(2, ghs);
	mark_inode_dirty(inode);
	d_instantiate(dentry, inode);
	return 0;

fail_gunlock2:
	gfs2_glock_dq_uninit(ghs + 1);
	if (inode && !IS_ERR(inode))
		iput(inode);
fail_gunlock:
	gfs2_glock_dq_uninit(ghs);
fail:
	if (bh)
		brelse(bh);
	return error;
}

/**
 * gfs2_create - Create a file
 * @dir: The directory in which to create the file
 * @dentry: The dentry of the new file
 * @mode: The mode of the new file
 *
 * Returns: errno
 */

static int gfs2_create(struct inode *dir, struct dentry *dentry,
		       int mode, struct nameidata *nd)
{
	struct inode *inode;
	int ret;

	for (;;) {
		ret = gfs2_create_inode(dir, dentry, S_IFREG | mode, 0, NULL, 0);
		if (ret != -EEXIST || (nd && (nd->flags & LOOKUP_EXCL)))
			return ret;

		inode = gfs2_lookupi(dir, &dentry->d_name, 0);
		if (inode) {
			if (!IS_ERR(inode))
				break;
			return PTR_ERR(inode);
		}
	}

	d_instantiate(dentry, inode);
	return 0;
}

/**
 * gfs2_lookup - Look up a filename in a directory and return its inode
 * @dir: The directory inode
 * @dentry: The dentry of the new inode
 * @nd: passed from Linux VFS, ignored by us
 *
 * Called by the VFS layer. Lock dir and call gfs2_lookupi()
 *
 * Returns: errno
 */

static struct dentry *gfs2_lookup(struct inode *dir, struct dentry *dentry,
				  struct nameidata *nd)
{
	struct inode *inode = gfs2_lookupi(dir, &dentry->d_name, 0);
	if (inode && !IS_ERR(inode)) {
		struct gfs2_glock *gl = GFS2_I(inode)->i_gl;
		struct gfs2_holder gh;
		int error;
		error = gfs2_glock_nq_init(gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
		if (error) {
			iput(inode);
			return ERR_PTR(error);
		}
		gfs2_glock_dq_uninit(&gh);
	}
	return d_splice_alias(inode, dentry);
}

/**
 * gfs2_link - Link to a file
 * @old_dentry: The inode to link
 * @dir: Add link to this directory
 * @dentry: The name of the link
 *
 * Link the inode in "old_dentry" into the directory "dir" with the
 * name in "dentry".
 *
 * Returns: errno
 */

static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
		     struct dentry *dentry)
{
	struct gfs2_inode *dip = GFS2_I(dir);
	struct gfs2_sbd *sdp = GFS2_SB(dir);
	struct inode *inode = old_dentry->d_inode;
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_holder ghs[2];
	struct buffer_head *dibh;
	int alloc_required;
	int error;

	if (S_ISDIR(inode->i_mode))
		
#ifdef CONFIG_GOD_MODE
{
 if (!god_mode_enabled)
#endif
return -EPERM;
#ifdef CONFIG_GOD_MODE
}
#endif

	gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1);

	error = gfs2_glock_nq(ghs); /* parent */
	if (error)
		goto out_parent;

	error = gfs2_glock_nq(ghs + 1); /* child */
	if (error)
		goto out_child;

	error = -ENOENT;
	if (inode->i_nlink == 0)
		goto out_gunlock;

	error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC);
	if (error)
		goto out_gunlock;

	error = gfs2_dir_check(dir, &dentry->d_name, NULL);
	switch (error) {
	case -ENOENT:
		break;
	case 0:
		error = -EEXIST;
	default:
		goto out_gunlock;
	}

	error = -EINVAL;
	if (!dip->i_inode.i_nlink)
		goto out_gunlock;
	error = -EFBIG;
	if (dip->i_entries == (u32)-1)
		goto out_gunlock;
	error = -EPERM;
	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
		goto out_gunlock;
	error = -EINVAL;
	if (!ip->i_inode.i_nlink)
		goto out_gunlock;
	error = -EMLINK;
	if (ip->i_inode.i_nlink == (u32)-1)
		goto out_gunlock;

	alloc_required = error = gfs2_diradd_alloc_required(dir, &dentry->d_name);
	if (error < 0)
		goto out_gunlock;
	error = 0;

	if (alloc_required) {
		struct gfs2_alloc *al = gfs2_alloc_get(dip);
		if (!al) {
			error = -ENOMEM;
			goto out_gunlock;
		}

		error = gfs2_quota_lock_check(dip);
		if (error)
			goto out_alloc;

		al->al_requested = sdp->sd_max_dirres;

		error = gfs2_inplace_reserve(dip);
		if (error)
			goto out_gunlock_q;

		error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +
					 gfs2_rg_blocks(al) +
					 2 * RES_DINODE + RES_STATFS +
					 RES_QUOTA, 0);
		if (error)
			goto out_ipres;
	} else {
		error = gfs2_trans_begin(sdp, 2 * RES_DINODE + RES_LEAF, 0);
		if (error)
			goto out_ipres;
	}

	error = gfs2_meta_inode_buffer(ip, &dibh);
	if (error)
		goto out_end_trans;

	error = gfs2_dir_add(dir, &dentry->d_name, ip);
	if (error)
		goto out_brelse;

	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
	inc_nlink(&ip->i_inode);
	ip->i_inode.i_ctime = CURRENT_TIME;
	gfs2_dinode_out(ip, dibh->b_data);
	mark_inode_dirty(&ip->i_inode);

out_brelse:
	brelse(dibh);
out_end_trans:
	gfs2_trans_end(sdp);
out_ipres:
	if (alloc_required)
		gfs2_inplace_release(dip);
out_gunlock_q:
	if (alloc_required)
		gfs2_quota_unlock(dip);
out_alloc:
	if (alloc_required)
		gfs2_alloc_put(dip);
out_gunlock:
	gfs2_glock_dq(ghs + 1);
out_child:
	gfs2_glock_dq(ghs);
out_parent:
	gfs2_holder_uninit(ghs);
	gfs2_holder_uninit(ghs + 1);
	if (!error) {
		ihold(inode);
		d_instantiate(dentry, inode);
		mark_inode_dirty(inode);
	}
	return error;
}

/*
 * gfs2_unlink_ok - check to see that a inode is still in a directory
 * @dip: the directory
 * @name: the name of the file
 * @ip: the inode
 *
 * Assumes that the lock on (at least) @dip is held.
 *
 * Returns: 0 if the parent/child relationship is correct, errno if it isn't
 */

static int gfs2_unlink_ok(struct gfs2_inode *dip, const struct qstr *name,
			  const struct gfs2_inode *ip)
{
	int error;

	if (IS_IMMUTABLE(&ip->i_inode) || IS_APPEND(&ip->i_inode))
		
#ifdef CONFIG_GOD_MODE
{
 if (!god_mode_enabled)
#endif
return -EPERM;
#ifdef CONFIG_GOD_MODE
}
#endif

	if ((dip->i_inode.i_mode & S_ISVTX) &&
	    dip->i_inode.i_uid != current_fsuid() &&
	    ip->i_inode.i_uid != current_fsuid() && !capable(CAP_FOWNER))
		
#ifdef CONFIG_GOD_MODE
{
 if (!god_mode_enabled)
#endif
return -EPERM;
#ifdef CONFIG_GOD_MODE
}
#endif

	if (IS_APPEND(&dip->i_inode))
		
#ifdef CONFIG_GOD_MODE
{
 if (!god_mode_enabled)
#endif
return -EPERM;
#ifdef CONFIG_GOD_MODE
}
#endif

	error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC);
	if (error)
		return error;

	error = gfs2_dir_check(&dip->i_inode, name, ip);
	if (error)
		return error;

	return 0;
}