| /* |
| * 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; |
| } |
| |
| static struct posix_acl *gfs2_acl_get(struct gfs2_inode *ip, int type) |
| { |
| 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(data, len); |
| kfree(data); |
| return acl; |
| } |
| |
| /** |
| * gfs2_check_acl - Check an ACL to see if we're allowed to do something |
| * @inode: the file we want to do something to |
| * @mask: what we want to do |
| * |
| * Returns: errno |
| */ |
| |
| int gfs2_check_acl(struct inode *inode, int mask) |
| { |
| struct posix_acl *acl; |
| int error; |
| |
| acl = gfs2_acl_get(GFS2_I(inode), ACL_TYPE_ACCESS); |
| if (IS_ERR(acl)) |
| return PTR_ERR(acl); |
| |
| if (acl) { |
| error = posix_acl_permission(inode, acl, mask); |
| posix_acl_release(acl); |
| return error; |
| } |
| |
| return -EAGAIN; |
| } |
| |
| static int gfs2_set_mode(struct inode *inode, mode_t mode) |
| { |
| int error = 0; |
| |
| if (mode != inode->i_mode) { |
| struct iattr iattr; |
| |
| iattr.ia_valid = ATTR_MODE; |
| iattr.ia_mode = mode; |
| |
| error = gfs2_setattr_simple(GFS2_I(inode), &iattr); |
| } |
| |
| 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(acl, NULL, 0); |
| if (len == 0) |
| return 0; |
| data = kmalloc(len, GFP_NOFS); |
| if (data == NULL) |
| return -ENOMEM; |
| error = posix_acl_to_xattr(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; |
| mode_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_acl_get(dip, ACL_TYPE_DEFAULT); |
| if (IS_ERR(acl)) |
| return PTR_ERR(acl); |
| if (!acl) { |
| mode &= ~current_umask(); |
| if (mode != inode->i_mode) |
| error = gfs2_set_mode(inode, mode); |
| return error; |
| } |
| |
| 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 posix_acl *acl; |
| char *data; |
| unsigned int len; |
| int error; |
| |
| acl = gfs2_acl_get(ip, ACL_TYPE_ACCESS); |
| if (IS_ERR(acl)) |
| return PTR_ERR(acl); |
| if (!acl) |
| return gfs2_setattr_simple(ip, attr); |
| |
| error = posix_acl_chmod(&acl, GFP_NOFS, attr->ia_mode); |
| if (error) |
| return error; |
| |
| len = posix_acl_to_xattr(acl, NULL, 0); |
| data = kmalloc(len, GFP_NOFS); |
| error = -ENOMEM; |
| if (data == NULL) |
| goto out; |
| posix_acl_to_xattr(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_acl_get(GFS2_I(inode), type); |
| if (IS_ERR(acl)) |
| return PTR_ERR(acl); |
| if (acl == NULL) |
| return -ENODATA; |
| |
| error = posix_acl_to_xattr(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 ((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(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) { |
| mode_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, |
| }; |
| |