diff options
Diffstat (limited to 'fs/gfs2/acl.c')
| -rw-r--r-- | fs/gfs2/acl.c | 312 |
1 files changed, 312 insertions, 0 deletions
diff --git a/fs/gfs2/acl.c b/fs/gfs2/acl.c new file mode 100644 index 000000000000..33c465a2ab53 --- /dev/null +++ b/fs/gfs2/acl.c @@ -0,0 +1,312 @@ +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2005 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 v.2. + */ + +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/buffer_head.h> +#include <linux/posix_acl.h> +#include <linux/posix_acl_xattr.h> +#include <asm/semaphore.h> + +#include "gfs2.h" +#include "acl.h" +#include "eaops.h" +#include "eattr.h" +#include "glock.h" +#include "inode.h" +#include "meta_io.h" +#include "trans.h" + +#define ACL_ACCESS 1 +#define ACL_DEFAULT 0 + +int gfs2_acl_validate_set(struct gfs2_inode *ip, int access, + struct gfs2_ea_request *er, + int *remove, mode_t *mode) +{ + struct posix_acl *acl; + int error; + + error = gfs2_acl_validate_remove(ip, access); + if (error) + return error; + + if (!er->er_data) + return -EINVAL; + + acl = posix_acl_from_xattr(er->er_data, er->er_data_len); + if (IS_ERR(acl)) + return PTR_ERR(acl); + if (!acl) { + *remove = 1; + return 0; + } + + error = posix_acl_valid(acl); + if (error) + goto out; + + if (access) { + error = posix_acl_equiv_mode(acl, mode); + if (!error) + *remove = 1; + else if (error > 0) + error = 0; + } + + out: + posix_acl_release(acl); + + return error; +} + +int gfs2_acl_validate_remove(struct gfs2_inode *ip, int access) +{ + if (!ip->i_sbd->sd_args.ar_posix_acl) + return -EOPNOTSUPP; + if (current->fsuid != ip->i_di.di_uid && !capable(CAP_FOWNER)) + return -EPERM; + if (S_ISLNK(ip->i_di.di_mode)) + return -EOPNOTSUPP; + if (!access && !S_ISDIR(ip->i_di.di_mode)) + return -EACCES; + + return 0; +} + +static int acl_get(struct gfs2_inode *ip, int access, struct posix_acl **acl, + struct gfs2_ea_location *el, char **data, unsigned int *len) +{ + struct gfs2_ea_request er; + struct gfs2_ea_location el_this; + int error; + + if (!ip->i_di.di_eattr) + return 0; + + memset(&er, 0, sizeof(struct gfs2_ea_request)); + if (access) { + er.er_name = GFS2_POSIX_ACL_ACCESS; + er.er_name_len = GFS2_POSIX_ACL_ACCESS_LEN; + } else { + er.er_name = GFS2_POSIX_ACL_DEFAULT; + er.er_name_len = GFS2_POSIX_ACL_DEFAULT_LEN; + } + er.er_type = GFS2_EATYPE_SYS; + + if (!el) + el = &el_this; + + error = gfs2_ea_find(ip, &er, el); + if (error) + return error; + if (!el->el_ea) + return 0; + if (!GFS2_EA_DATA_LEN(el->el_ea)) + goto out; + + er.er_data_len = GFS2_EA_DATA_LEN(el->el_ea); + er.er_data = kmalloc(er.er_data_len, GFP_KERNEL); + error = -ENOMEM; + if (!er.er_data) + goto out; + + error = gfs2_ea_get_copy(ip, el, er.er_data); + if (error) + goto out_kfree; + + if (acl) { + *acl = posix_acl_from_xattr(er.er_data, er.er_data_len); + if (IS_ERR(*acl)) + error = PTR_ERR(*acl); + } + + out_kfree: + if (error || !data) + kfree(er.er_data); + else { + *data = er.er_data; + *len = er.er_data_len; + } + + out: + if (error || el == &el_this) + brelse(el->el_bh); + + return error; +} + +/** + * gfs2_check_acl_locked - 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_locked(struct inode *inode, int mask) +{ + struct posix_acl *acl = NULL; + int error; + + error = acl_get(get_v2ip(inode), ACL_ACCESS, &acl, NULL, NULL, NULL); + if (error) + return error; + + if (acl) { + error = posix_acl_permission(inode, acl, mask); + posix_acl_release(acl); + return error; + } + + return -EAGAIN; +} + +int gfs2_check_acl(struct inode *inode, int mask) +{ + struct gfs2_inode *ip = get_v2ip(inode); + struct gfs2_holder i_gh; + int error; + + error = gfs2_glock_nq_init(ip->i_gl, + LM_ST_SHARED, LM_FLAG_ANY, + &i_gh); + if (!error) { + error = gfs2_check_acl_locked(inode, mask); + gfs2_glock_dq_uninit(&i_gh); + } + + return error; +} + +static int munge_mode(struct gfs2_inode *ip, mode_t mode) +{ + struct gfs2_sbd *sdp = ip->i_sbd; + struct buffer_head *dibh; + int error; + + error = gfs2_trans_begin(sdp, RES_DINODE, 0); + if (error) + return error; + + error = gfs2_meta_inode_buffer(ip, &dibh); + if (!error) { + gfs2_assert_withdraw(sdp, + (ip->i_di.di_mode & S_IFMT) == (mode & S_IFMT)); + ip->i_di.di_mode = mode; + gfs2_trans_add_bh(ip->i_gl, dibh); + gfs2_dinode_out(&ip->i_di, dibh->b_data); + brelse(dibh); + } + + gfs2_trans_end(sdp); + + return 0; +} + +int gfs2_acl_create(struct gfs2_inode *dip, struct gfs2_inode *ip) +{ + struct gfs2_sbd *sdp = dip->i_sbd; + struct posix_acl *acl = NULL, *clone; + struct gfs2_ea_request er; + mode_t mode = ip->i_di.di_mode; + int error; + + if (!sdp->sd_args.ar_posix_acl) + return 0; + if (S_ISLNK(ip->i_di.di_mode)) + return 0; + + memset(&er, 0, sizeof(struct gfs2_ea_request)); + er.er_type = GFS2_EATYPE_SYS; + + error = acl_get(dip, ACL_DEFAULT, &acl, NULL, + &er.er_data, &er.er_data_len); + if (error) + return error; + if (!acl) { + mode &= ~current->fs->umask; + if (mode != ip->i_di.di_mode) + error = munge_mode(ip, mode); + return error; + } + + clone = posix_acl_clone(acl, GFP_KERNEL); + error = -ENOMEM; + if (!clone) + goto out; + posix_acl_release(acl); + acl = clone; + + if (S_ISDIR(ip->i_di.di_mode)) { + er.er_name = GFS2_POSIX_ACL_DEFAULT; + er.er_name_len = GFS2_POSIX_ACL_DEFAULT_LEN; + error = gfs2_system_eaops.eo_set(ip, &er); + if (error) + goto out; + } + + error = posix_acl_create_masq(acl, &mode); + if (error < 0) + goto out; + if (error > 0) { + er.er_name = GFS2_POSIX_ACL_ACCESS; + er.er_name_len = GFS2_POSIX_ACL_ACCESS_LEN; + posix_acl_to_xattr(acl, er.er_data, er.er_data_len); + er.er_mode = mode; + er.er_flags = GFS2_ERF_MODE; + error = gfs2_system_eaops.eo_set(ip, &er); + if (error) + goto out; + } else + munge_mode(ip, mode); + + out: + posix_acl_release(acl); + kfree(er.er_data); + return error; +} + +int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr) +{ + struct posix_acl *acl = NULL, *clone; + struct gfs2_ea_location el; + char *data; + unsigned int len; + int error; + + error = acl_get(ip, ACL_ACCESS, &acl, &el, &data, &len); + if (error) + return error; + if (!acl) + return gfs2_setattr_simple(ip, attr); + + clone = posix_acl_clone(acl, GFP_KERNEL); + error = -ENOMEM; + if (!clone) + goto out; + posix_acl_release(acl); + acl = clone; + + error = posix_acl_chmod_masq(acl, attr->ia_mode); + if (!error) { + posix_acl_to_xattr(acl, data, len); + error = gfs2_ea_acl_chmod(ip, &el, attr, data); + } + + out: + posix_acl_release(acl); + brelse(el.el_bh); + kfree(data); + + return error; +} + |