int
xfs_readlink_by_handle(
struct file *parfilp,
xfs_fsop_handlereq_t *hreq)
{
struct dentry *dentry;
__u32 olen;
int error;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
dentry = xfs_handlereq_to_dentry(parfilp, hreq);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
/* Restrict this handle operation to symlinks only. */
if (!d_is_symlink(dentry)) {
error = -EINVAL;
goto out_dput;
}
if (copy_from_user(&olen, hreq->ohandlen, sizeof(__u32))) {
error = -EFAULT;
goto out_dput;
}
error = vfs_readlink(dentry, hreq->ohandle, olen);
out_dput:
dput(dentry);
return error;
}
int
xfs_readlink_by_handle(
struct file *parfilp,
xfs_fsop_handlereq_t *hreq)
{
struct dentry *dentry;
__u32 olen;
void *link;
int error;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
dentry = xfs_handlereq_to_dentry(parfilp, hreq);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
/* Restrict this handle operation to symlinks only. */
if (!d_is_symlink(dentry)) {
error = -EINVAL;
goto out_dput;
}
if (copy_from_user(&olen, hreq->ohandlen, sizeof(__u32))) {
error = -EFAULT;
goto out_dput;
}
link = kmalloc(MAXPATHLEN+1, GFP_KERNEL);
if (!link) {
error = -ENOMEM;
goto out_dput;
}
error = xfs_readlink(XFS_I(d_inode(dentry)), link);
if (error)
goto out_kfree;
error = readlink_copy(hreq->ohandle, olen, link);
if (error)
goto out_kfree;
out_kfree:
kfree(link);
out_dput:
dput(dentry);
return error;
}
int
gr_handle_follow_link(const struct dentry *dentry, const struct vfsmount *mnt)
{
#ifdef CONFIG_GRKERNSEC_LINK
struct inode *inode = d_backing_inode(dentry);
struct inode *parent = d_backing_inode(dentry->d_parent);
const struct cred *cred = current_cred();
if (grsec_enable_link && d_is_symlink(dentry) &&
(parent->i_mode & S_ISVTX) && !uid_eq(parent->i_uid, inode->i_uid) &&
(parent->i_mode & S_IWOTH) && !uid_eq(cred->fsuid, inode->i_uid)) {
gr_log_fs_int2(GR_DONT_AUDIT, GR_SYMLINK_MSG, dentry, mnt, inode->i_uid, inode->i_gid);
return -EACCES;
}
#endif
return 0;
}
/* Check if 'dentry' should expire, or return a nearby
* dentry that is suitable.
* If returned dentry is different from arg dentry,
* then a dget() reference was taken, else not.
*/
static struct dentry *should_expire(struct dentry *dentry,
struct vfsmount *mnt,
unsigned long timeout,
int how)
{
int do_now = how & AUTOFS_EXP_IMMEDIATE;
int exp_leaves = how & AUTOFS_EXP_LEAVES;
struct autofs_info *ino = autofs4_dentry_ino(dentry);
unsigned int ino_count;
/* No point expiring a pending mount */
if (ino->flags & AUTOFS_INF_PENDING)
return NULL;
/*
* Case 1: (i) indirect mount or top level pseudo direct mount
* (autofs-4.1).
* (ii) indirect mount with offset mount, check the "/"
* offset (autofs-5.0+).
*/
if (d_mountpoint(dentry)) {
pr_debug("checking mountpoint %p %pd\n", dentry, dentry);
/* Can we umount this guy */
if (autofs4_mount_busy(mnt, dentry))
return NULL;
/* Can we expire this guy */
if (autofs4_can_expire(dentry, timeout, do_now))
return dentry;
return NULL;
}
if (d_really_is_positive(dentry) && d_is_symlink(dentry)) {
pr_debug("checking symlink %p %pd\n", dentry, dentry);
/*
* A symlink can't be "busy" in the usual sense so
* just check last used for expire timeout.
*/
if (autofs4_can_expire(dentry, timeout, do_now))
return dentry;
return NULL;
}
if (simple_empty(dentry))
return NULL;
/* Case 2: tree mount, expire iff entire tree is not busy */
if (!exp_leaves) {
/* Path walk currently on this dentry? */
ino_count = atomic_read(&ino->count) + 1;
if (d_count(dentry) > ino_count)
return NULL;
if (!autofs4_tree_busy(mnt, dentry, timeout, do_now))
return dentry;
/*
* Case 3: pseudo direct mount, expire individual leaves
* (autofs-4.1).
*/
} else {
/* Path walk currently on this dentry? */
struct dentry *expired;
ino_count = atomic_read(&ino->count) + 1;
if (d_count(dentry) > ino_count)
return NULL;
expired = autofs4_check_leaves(mnt, dentry, timeout, do_now);
if (expired) {
if (expired == dentry)
dput(dentry);
return expired;
}
}
return NULL;
}
/*
* Do a lookup + open with a single request. If we get a non-existent
* file or symlink, return 1 so the VFS can retry.
*/
int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
struct file *file, unsigned flags, umode_t mode,
int *opened)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_mds_request *req;
struct dentry *dn;
struct ceph_acls_info acls = {};
int err;
dout("atomic_open %p dentry %p '%pd' %s flags %d mode 0%o\n",
dir, dentry, dentry,
d_unhashed(dentry) ? "unhashed" : "hashed", flags, mode);
if (dentry->d_name.len > NAME_MAX)
return -ENAMETOOLONG;
err = ceph_init_dentry(dentry);
if (err < 0)
return err;
if (flags & O_CREAT) {
err = ceph_pre_init_acls(dir, &mode, &acls);
if (err < 0)
return err;
}
/* do the open */
req = prepare_open_request(dir->i_sb, flags, mode);
if (IS_ERR(req)) {
err = PTR_ERR(req);
goto out_acl;
}
req->r_dentry = dget(dentry);
req->r_num_caps = 2;
if (flags & O_CREAT) {
req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
if (acls.pagelist) {
req->r_pagelist = acls.pagelist;
acls.pagelist = NULL;
}
}
req->r_locked_dir = dir; /* caller holds dir->i_mutex */
err = ceph_mdsc_do_request(mdsc,
(flags & (O_CREAT|O_TRUNC)) ? dir : NULL,
req);
err = ceph_handle_snapdir(req, dentry, err);
if (err)
goto out_req;
if ((flags & O_CREAT) && !req->r_reply_info.head->is_dentry)
err = ceph_handle_notrace_create(dir, dentry);
if (d_unhashed(dentry)) {
dn = ceph_finish_lookup(req, dentry, err);
if (IS_ERR(dn))
err = PTR_ERR(dn);
} else {
/* we were given a hashed negative dentry */
dn = NULL;
}
if (err)
goto out_req;
if (dn || d_really_is_negative(dentry) || d_is_symlink(dentry)) {
/* make vfs retry on splice, ENOENT, or symlink */
dout("atomic_open finish_no_open on dn %p\n", dn);
err = finish_no_open(file, dn);
} else {
dout("atomic_open finish_open on dn %p\n", dn);
if (req->r_op == CEPH_MDS_OP_CREATE && req->r_reply_info.has_create_ino) {
ceph_init_inode_acls(d_inode(dentry), &acls);
*opened |= FILE_CREATED;
}
err = finish_open(file, dentry, ceph_open, opened);
}
out_req:
if (!req->r_err && req->r_target_inode)
ceph_put_fmode(ceph_inode(req->r_target_inode), req->r_fmode);
ceph_mdsc_put_request(req);
out_acl:
ceph_release_acls_info(&acls);
dout("atomic_open result=%d\n", err);
return err;
}
