519 строки
12 KiB
C
519 строки
12 KiB
C
#include <linux/capability.h>
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#include <linux/fs.h>
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#include <linux/posix_acl.h>
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#include "reiserfs.h"
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#include <linux/errno.h>
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#include <linux/pagemap.h>
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#include <linux/xattr.h>
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#include <linux/slab.h>
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#include <linux/posix_acl_xattr.h>
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#include "xattr.h"
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#include "acl.h"
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#include <asm/uaccess.h>
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static int reiserfs_set_acl(struct reiserfs_transaction_handle *th,
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struct inode *inode, int type,
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struct posix_acl *acl);
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static int
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posix_acl_set(struct dentry *dentry, const char *name, const void *value,
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size_t size, int flags, int type)
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{
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struct inode *inode = dentry->d_inode;
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struct posix_acl *acl;
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int error, error2;
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struct reiserfs_transaction_handle th;
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size_t jcreate_blocks;
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if (!reiserfs_posixacl(inode->i_sb))
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return -EOPNOTSUPP;
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if (!inode_owner_or_capable(inode))
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return -EPERM;
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if (value) {
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acl = posix_acl_from_xattr(&init_user_ns, value, size);
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if (IS_ERR(acl)) {
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return PTR_ERR(acl);
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} else if (acl) {
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error = posix_acl_valid(acl);
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if (error)
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goto release_and_out;
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}
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} else
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acl = NULL;
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/* Pessimism: We can't assume that anything from the xattr root up
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* has been created. */
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jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) +
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reiserfs_xattr_nblocks(inode, size) * 2;
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reiserfs_write_lock(inode->i_sb);
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error = journal_begin(&th, inode->i_sb, jcreate_blocks);
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if (error == 0) {
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error = reiserfs_set_acl(&th, inode, type, acl);
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error2 = journal_end(&th, inode->i_sb, jcreate_blocks);
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if (error2)
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error = error2;
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}
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reiserfs_write_unlock(inode->i_sb);
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release_and_out:
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posix_acl_release(acl);
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return error;
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}
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static int
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posix_acl_get(struct dentry *dentry, const char *name, void *buffer,
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size_t size, int type)
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{
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struct posix_acl *acl;
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int error;
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if (!reiserfs_posixacl(dentry->d_sb))
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return -EOPNOTSUPP;
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acl = reiserfs_get_acl(dentry->d_inode, type);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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if (acl == NULL)
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return -ENODATA;
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error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
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posix_acl_release(acl);
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return error;
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}
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/*
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* Convert from filesystem to in-memory representation.
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*/
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static struct posix_acl *posix_acl_from_disk(const void *value, size_t size)
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{
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const char *end = (char *)value + size;
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int n, count;
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struct posix_acl *acl;
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if (!value)
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return NULL;
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if (size < sizeof(reiserfs_acl_header))
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return ERR_PTR(-EINVAL);
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if (((reiserfs_acl_header *) value)->a_version !=
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cpu_to_le32(REISERFS_ACL_VERSION))
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return ERR_PTR(-EINVAL);
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value = (char *)value + sizeof(reiserfs_acl_header);
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count = reiserfs_acl_count(size);
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if (count < 0)
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return ERR_PTR(-EINVAL);
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if (count == 0)
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return NULL;
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acl = posix_acl_alloc(count, GFP_NOFS);
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if (!acl)
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return ERR_PTR(-ENOMEM);
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for (n = 0; n < count; n++) {
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reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value;
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if ((char *)value + sizeof(reiserfs_acl_entry_short) > end)
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goto fail;
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acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
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acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
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switch (acl->a_entries[n].e_tag) {
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case ACL_USER_OBJ:
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case ACL_GROUP_OBJ:
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case ACL_MASK:
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case ACL_OTHER:
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value = (char *)value +
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sizeof(reiserfs_acl_entry_short);
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break;
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case ACL_USER:
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value = (char *)value + sizeof(reiserfs_acl_entry);
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if ((char *)value > end)
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goto fail;
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acl->a_entries[n].e_uid =
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make_kuid(&init_user_ns,
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le32_to_cpu(entry->e_id));
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break;
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case ACL_GROUP:
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value = (char *)value + sizeof(reiserfs_acl_entry);
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if ((char *)value > end)
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goto fail;
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acl->a_entries[n].e_gid =
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make_kgid(&init_user_ns,
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le32_to_cpu(entry->e_id));
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break;
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default:
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goto fail;
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}
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}
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if (value != end)
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goto fail;
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return acl;
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fail:
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posix_acl_release(acl);
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return ERR_PTR(-EINVAL);
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}
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/*
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* Convert from in-memory to filesystem representation.
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*/
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static void *posix_acl_to_disk(const struct posix_acl *acl, size_t * size)
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{
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reiserfs_acl_header *ext_acl;
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char *e;
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int n;
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*size = reiserfs_acl_size(acl->a_count);
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ext_acl = kmalloc(sizeof(reiserfs_acl_header) +
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acl->a_count *
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sizeof(reiserfs_acl_entry),
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GFP_NOFS);
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if (!ext_acl)
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return ERR_PTR(-ENOMEM);
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ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION);
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e = (char *)ext_acl + sizeof(reiserfs_acl_header);
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for (n = 0; n < acl->a_count; n++) {
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const struct posix_acl_entry *acl_e = &acl->a_entries[n];
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reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e;
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entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
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entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
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switch (acl->a_entries[n].e_tag) {
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case ACL_USER:
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entry->e_id = cpu_to_le32(
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from_kuid(&init_user_ns, acl_e->e_uid));
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e += sizeof(reiserfs_acl_entry);
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break;
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case ACL_GROUP:
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entry->e_id = cpu_to_le32(
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from_kgid(&init_user_ns, acl_e->e_gid));
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e += sizeof(reiserfs_acl_entry);
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break;
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case ACL_USER_OBJ:
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case ACL_GROUP_OBJ:
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case ACL_MASK:
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case ACL_OTHER:
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e += sizeof(reiserfs_acl_entry_short);
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break;
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default:
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goto fail;
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}
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}
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return (char *)ext_acl;
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fail:
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kfree(ext_acl);
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return ERR_PTR(-EINVAL);
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}
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/*
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* Inode operation get_posix_acl().
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*
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* inode->i_mutex: down
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* BKL held [before 2.5.x]
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*/
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struct posix_acl *reiserfs_get_acl(struct inode *inode, int type)
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{
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char *name, *value;
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struct posix_acl *acl;
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int size;
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int retval;
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acl = get_cached_acl(inode, type);
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if (acl != ACL_NOT_CACHED)
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return acl;
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switch (type) {
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case ACL_TYPE_ACCESS:
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name = POSIX_ACL_XATTR_ACCESS;
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break;
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case ACL_TYPE_DEFAULT:
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name = POSIX_ACL_XATTR_DEFAULT;
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break;
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default:
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BUG();
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}
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size = reiserfs_xattr_get(inode, name, NULL, 0);
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if (size < 0) {
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if (size == -ENODATA || size == -ENOSYS) {
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set_cached_acl(inode, type, NULL);
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return NULL;
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}
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return ERR_PTR(size);
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}
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value = kmalloc(size, GFP_NOFS);
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if (!value)
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return ERR_PTR(-ENOMEM);
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retval = reiserfs_xattr_get(inode, name, value, size);
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if (retval == -ENODATA || retval == -ENOSYS) {
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/* This shouldn't actually happen as it should have
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been caught above.. but just in case */
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acl = NULL;
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} else if (retval < 0) {
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acl = ERR_PTR(retval);
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} else {
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acl = posix_acl_from_disk(value, retval);
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}
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if (!IS_ERR(acl))
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set_cached_acl(inode, type, acl);
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kfree(value);
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return acl;
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}
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/*
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* Inode operation set_posix_acl().
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*
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* inode->i_mutex: down
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* BKL held [before 2.5.x]
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*/
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static int
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reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode,
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int type, struct posix_acl *acl)
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{
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char *name;
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void *value = NULL;
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size_t size = 0;
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int error;
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if (S_ISLNK(inode->i_mode))
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return -EOPNOTSUPP;
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switch (type) {
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case ACL_TYPE_ACCESS:
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name = POSIX_ACL_XATTR_ACCESS;
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if (acl) {
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error = posix_acl_equiv_mode(acl, &inode->i_mode);
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if (error < 0)
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return error;
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else {
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if (error == 0)
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acl = NULL;
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}
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}
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break;
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case ACL_TYPE_DEFAULT:
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name = POSIX_ACL_XATTR_DEFAULT;
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if (!S_ISDIR(inode->i_mode))
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return acl ? -EACCES : 0;
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break;
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default:
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return -EINVAL;
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}
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if (acl) {
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value = posix_acl_to_disk(acl, &size);
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if (IS_ERR(value))
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return (int)PTR_ERR(value);
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}
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error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0);
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/*
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* Ensure that the inode gets dirtied if we're only using
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* the mode bits and an old ACL didn't exist. We don't need
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* to check if the inode is hashed here since we won't get
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* called by reiserfs_inherit_default_acl().
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*/
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if (error == -ENODATA) {
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error = 0;
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if (type == ACL_TYPE_ACCESS) {
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inode->i_ctime = CURRENT_TIME_SEC;
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mark_inode_dirty(inode);
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}
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}
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kfree(value);
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if (!error)
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set_cached_acl(inode, type, acl);
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return error;
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}
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/* dir->i_mutex: locked,
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* inode is new and not released into the wild yet */
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int
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reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th,
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struct inode *dir, struct dentry *dentry,
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struct inode *inode)
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{
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struct posix_acl *acl;
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int err = 0;
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/* ACLs only get applied to files and directories */
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if (S_ISLNK(inode->i_mode))
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return 0;
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/* ACLs can only be used on "new" objects, so if it's an old object
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* there is nothing to inherit from */
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if (get_inode_sd_version(dir) == STAT_DATA_V1)
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goto apply_umask;
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/* Don't apply ACLs to objects in the .reiserfs_priv tree.. This
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* would be useless since permissions are ignored, and a pain because
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* it introduces locking cycles */
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if (IS_PRIVATE(dir)) {
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inode->i_flags |= S_PRIVATE;
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goto apply_umask;
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}
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acl = reiserfs_get_acl(dir, ACL_TYPE_DEFAULT);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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if (acl) {
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/* Copy the default ACL to the default ACL of a new directory */
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if (S_ISDIR(inode->i_mode)) {
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err = reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT,
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acl);
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if (err)
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goto cleanup;
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}
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/* Now we reconcile the new ACL and the mode,
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potentially modifying both */
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err = posix_acl_create(&acl, GFP_NOFS, &inode->i_mode);
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if (err < 0)
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return err;
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/* If we need an ACL.. */
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if (err > 0)
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err = reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS, acl);
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cleanup:
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posix_acl_release(acl);
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} else {
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apply_umask:
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/* no ACL, apply umask */
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inode->i_mode &= ~current_umask();
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}
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return err;
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}
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/* This is used to cache the default acl before a new object is created.
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* The biggest reason for this is to get an idea of how many blocks will
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* actually be required for the create operation if we must inherit an ACL.
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* An ACL write can add up to 3 object creations and an additional file write
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* so we'd prefer not to reserve that many blocks in the journal if we can.
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* It also has the advantage of not loading the ACL with a transaction open,
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* this may seem silly, but if the owner of the directory is doing the
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* creation, the ACL may not be loaded since the permissions wouldn't require
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* it.
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* We return the number of blocks required for the transaction.
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*/
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int reiserfs_cache_default_acl(struct inode *inode)
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{
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struct posix_acl *acl;
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int nblocks = 0;
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if (IS_PRIVATE(inode))
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return 0;
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acl = reiserfs_get_acl(inode, ACL_TYPE_DEFAULT);
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if (acl && !IS_ERR(acl)) {
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int size = reiserfs_acl_size(acl->a_count);
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/* Other xattrs can be created during inode creation. We don't
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* want to claim too many blocks, so we check to see if we
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* we need to create the tree to the xattrs, and then we
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* just want two files. */
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nblocks = reiserfs_xattr_jcreate_nblocks(inode);
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nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb);
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REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
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/* We need to account for writes + bitmaps for two files */
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nblocks += reiserfs_xattr_nblocks(inode, size) * 4;
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posix_acl_release(acl);
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}
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return nblocks;
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}
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int reiserfs_acl_chmod(struct inode *inode)
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{
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struct reiserfs_transaction_handle th;
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struct posix_acl *acl;
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size_t size;
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int depth;
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int error;
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if (S_ISLNK(inode->i_mode))
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return -EOPNOTSUPP;
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if (get_inode_sd_version(inode) == STAT_DATA_V1 ||
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!reiserfs_posixacl(inode->i_sb)) {
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return 0;
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}
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reiserfs_write_unlock(inode->i_sb);
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acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
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reiserfs_write_lock(inode->i_sb);
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if (!acl)
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return 0;
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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error = posix_acl_chmod(&acl, GFP_NOFS, inode->i_mode);
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if (error)
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return error;
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size = reiserfs_xattr_nblocks(inode, reiserfs_acl_size(acl->a_count));
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depth = reiserfs_write_lock_once(inode->i_sb);
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error = journal_begin(&th, inode->i_sb, size * 2);
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if (!error) {
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int error2;
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error = reiserfs_set_acl(&th, inode, ACL_TYPE_ACCESS, acl);
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error2 = journal_end(&th, inode->i_sb, size * 2);
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if (error2)
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error = error2;
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}
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reiserfs_write_unlock_once(inode->i_sb, depth);
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posix_acl_release(acl);
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return error;
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}
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static size_t posix_acl_access_list(struct dentry *dentry, char *list,
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size_t list_size, const char *name,
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size_t name_len, int type)
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{
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const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
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if (!reiserfs_posixacl(dentry->d_sb))
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return 0;
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if (list && size <= list_size)
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memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
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return size;
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}
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const struct xattr_handler reiserfs_posix_acl_access_handler = {
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.prefix = POSIX_ACL_XATTR_ACCESS,
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.flags = ACL_TYPE_ACCESS,
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.get = posix_acl_get,
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.set = posix_acl_set,
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.list = posix_acl_access_list,
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};
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static size_t posix_acl_default_list(struct dentry *dentry, char *list,
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size_t list_size, const char *name,
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size_t name_len, int type)
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{
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const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
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if (!reiserfs_posixacl(dentry->d_sb))
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return 0;
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if (list && size <= list_size)
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memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
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return size;
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}
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const struct xattr_handler reiserfs_posix_acl_default_handler = {
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.prefix = POSIX_ACL_XATTR_DEFAULT,
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.flags = ACL_TYPE_DEFAULT,
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.get = posix_acl_get,
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.set = posix_acl_set,
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.list = posix_acl_default_list,
|
|
};
|