/* * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. * * This copyrighted material is made available to anyone wishing to use, * modify, copy, or redistribute it subject to the terms and conditions * of the GNU General Public License version 2. */ #include <linux/sched.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/completion.h> #include <linux/buffer_head.h> #include <linux/xattr.h> #include <linux/posix_acl.h> #include <linux/posix_acl_xattr.h> #include <linux/gfs2_ondisk.h> #include "gfs2.h" #include "incore.h" #include "acl.h" #include "xattr.h" #include "glock.h" #include "inode.h" #include "meta_io.h" #include "trans.h" #include "util.h" static const char *gfs2_acl_name(int type) { switch (type) { case ACL_TYPE_ACCESS: return GFS2_POSIX_ACL_ACCESS; case ACL_TYPE_DEFAULT: return GFS2_POSIX_ACL_DEFAULT; } return NULL; } struct posix_acl *gfs2_get_acl(struct inode *inode, int type) { struct gfs2_inode *ip = GFS2_I(inode); struct posix_acl *acl; const char *name; char *data; int len; if (!ip->i_eattr) return NULL; acl = get_cached_acl(&ip->i_inode, type); if (acl != ACL_NOT_CACHED) return acl; name = gfs2_acl_name(type); if (name == NULL) return ERR_PTR(-EINVAL); len = gfs2_xattr_acl_get(ip, name, &data); if (len < 0) return ERR_PTR(len); if (len == 0) return NULL; acl = posix_acl_from_xattr(&init_user_ns, data, len); kfree(data); return acl; } static int gfs2_set_mode(struct inode *inode, umode_t mode) { int error = 0; if (mode != inode->i_mode) { inode->i_mode = mode; mark_inode_dirty(inode); } return error; } static int gfs2_acl_set(struct inode *inode, int type, struct posix_acl *acl) { int error; int len; char *data; const char *name = gfs2_acl_name(type); BUG_ON(name == NULL); len = posix_acl_to_xattr(&init_user_ns, acl, NULL, 0); if (len == 0) return 0; data = kmalloc(len, GFP_NOFS); if (data == NULL) return -ENOMEM; error = posix_acl_to_xattr(&init_user_ns, acl, data, len); if (error < 0) goto out; error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS); if (!error) set_cached_acl(inode, type, acl); out: kfree(data); return error; } int gfs2_acl_create(struct gfs2_inode *dip, struct inode *inode) { struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode); struct posix_acl *acl; umode_t mode = inode->i_mode; int error = 0; if (!sdp->sd_args.ar_posix_acl) return 0; if (S_ISLNK(inode->i_mode)) return 0; acl = gfs2_get_acl(&dip->i_inode, ACL_TYPE_DEFAULT); if (IS_ERR(acl)) return PTR_ERR(acl); if (!acl) { mode &= ~current_umask(); return gfs2_set_mode(inode, mode); } if (S_ISDIR(inode->i_mode)) { error = gfs2_acl_set(inode, ACL_TYPE_DEFAULT, acl); if (error) goto out; } error = posix_acl_create(&acl, GFP_NOFS, &mode); if (error < 0) return error; if (error == 0) goto munge; error = gfs2_acl_set(inode, ACL_TYPE_ACCESS, acl); if (error) goto out; munge: error = gfs2_set_mode(inode, mode); out: posix_acl_release(acl); return error; } int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr) { struct inode *inode = &ip->i_inode; struct posix_acl *acl; char *data; unsigned int len; int error; acl = gfs2_get_acl(&ip->i_inode, ACL_TYPE_ACCESS); if (IS_ERR(acl)) return PTR_ERR(acl); if (!acl) return gfs2_setattr_simple(inode, attr); error = posix_acl_chmod(&acl, GFP_NOFS, attr->ia_mode); if (error) return error; len = posix_acl_to_xattr(&init_user_ns, acl, NULL, 0); data = kmalloc(len, GFP_NOFS); error = -ENOMEM; if (data == NULL) goto out; posix_acl_to_xattr(&init_user_ns, acl, data, len); error = gfs2_xattr_acl_chmod(ip, attr, data); kfree(data); set_cached_acl(&ip->i_inode, ACL_TYPE_ACCESS, acl); out: posix_acl_release(acl); return error; } static int gfs2_acl_type(const char *name) { if (strcmp(name, GFS2_POSIX_ACL_ACCESS) == 0) return ACL_TYPE_ACCESS; if (strcmp(name, GFS2_POSIX_ACL_DEFAULT) == 0) return ACL_TYPE_DEFAULT; return -EINVAL; } static int gfs2_xattr_system_get(struct dentry *dentry, const char *name, void *buffer, size_t size, int xtype) { struct inode *inode = dentry->d_inode; struct gfs2_sbd *sdp = GFS2_SB(inode); struct posix_acl *acl; int type; int error; if (!sdp->sd_args.ar_posix_acl) return -EOPNOTSUPP; type = gfs2_acl_type(name); if (type < 0) return type; acl = gfs2_get_acl(inode, type); if (IS_ERR(acl)) return PTR_ERR(acl); if (acl == NULL) return -ENODATA; error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size); posix_acl_release(acl); return error; } static int gfs2_xattr_system_set(struct dentry *dentry, const char *name, const void *value, size_t size, int flags, int xtype) { struct inode *inode = dentry->d_inode; struct gfs2_sbd *sdp = GFS2_SB(inode); struct posix_acl *acl = NULL; int error = 0, type; if (!sdp->sd_args.ar_posix_acl) return -EOPNOTSUPP; type = gfs2_acl_type(name); if (type < 0) return type; if (flags & XATTR_CREATE) return -EINVAL; if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode)) return value ? -EACCES : 0; if (!uid_eq(current_fsuid(), inode->i_uid) && !capable(CAP_FOWNER)) return -EPERM; if (S_ISLNK(inode->i_mode)) return -EOPNOTSUPP; if (!value) goto set_acl; acl = posix_acl_from_xattr(&init_user_ns, value, size); if (!acl) { /* * acl_set_file(3) may request that we set default ACLs with * zero length -- defend (gracefully) against that here. */ goto out; } if (IS_ERR(acl)) { error = PTR_ERR(acl); goto out; } error = posix_acl_valid(acl); if (error) goto out_release; error = -EINVAL; if (acl->a_count > GFS2_ACL_MAX_ENTRIES) goto out_release; if (type == ACL_TYPE_ACCESS) { umode_t mode = inode->i_mode; error = posix_acl_equiv_mode(acl, &mode); if (error <= 0) { posix_acl_release(acl); acl = NULL; if (error < 0) return error; } error = gfs2_set_mode(inode, mode); if (error) goto out_release; } set_acl: error = __gfs2_xattr_set(inode, name, value, size, 0, GFS2_EATYPE_SYS); if (!error) { if (acl) set_cached_acl(inode, type, acl); else forget_cached_acl(inode, type); } out_release: posix_acl_release(acl); out: return error; } const struct xattr_handler gfs2_xattr_system_handler = { .prefix = XATTR_SYSTEM_PREFIX, .flags = GFS2_EATYPE_SYS, .get = gfs2_xattr_system_get, .set = gfs2_xattr_system_set, };