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408 lines
9.7 KiB
408 lines
9.7 KiB
// SPDX-License-Identifier: GPL-2.0 |
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#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 <linux/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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int |
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reiserfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode, |
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struct posix_acl *acl, int type) |
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{ |
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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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int size = acl ? posix_acl_xattr_size(acl->a_count) : 0; |
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int update_mode = 0; |
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umode_t mode = inode->i_mode; |
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|
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/* |
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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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*/ |
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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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reiserfs_write_unlock(inode->i_sb); |
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if (error == 0) { |
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if (type == ACL_TYPE_ACCESS && acl) { |
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error = posix_acl_update_mode(&init_user_ns, inode, |
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&mode, &acl); |
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if (error) |
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goto unlock; |
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update_mode = 1; |
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} |
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error = __reiserfs_set_acl(&th, inode, type, acl); |
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if (!error && update_mode) |
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inode->i_mode = mode; |
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unlock: |
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reiserfs_write_lock(inode->i_sb); |
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error2 = journal_end(&th); |
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reiserfs_write_unlock(inode->i_sb); |
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if (error2) |
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error = error2; |
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} |
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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 *reiserfs_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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|
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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 *reiserfs_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, bool rcu) |
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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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if (rcu) |
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return ERR_PTR(-ECHILD); |
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switch (type) { |
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case ACL_TYPE_ACCESS: |
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name = XATTR_NAME_POSIX_ACL_ACCESS; |
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break; |
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case ACL_TYPE_DEFAULT: |
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name = XATTR_NAME_POSIX_ACL_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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return NULL; |
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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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/* |
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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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*/ |
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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 = reiserfs_posix_acl_from_disk(value, retval); |
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} |
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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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switch (type) { |
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case ACL_TYPE_ACCESS: |
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name = XATTR_NAME_POSIX_ACL_ACCESS; |
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break; |
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case ACL_TYPE_DEFAULT: |
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name = XATTR_NAME_POSIX_ACL_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 = reiserfs_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(inode); |
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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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/* |
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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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*/ |
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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 *default_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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/* |
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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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*/ |
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if (get_inode_sd_version(dir) == STAT_DATA_V1) |
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goto apply_umask; |
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/* |
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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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*/ |
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if (IS_PRIVATE(inode)) |
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goto apply_umask; |
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err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); |
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if (err) |
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return err; |
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if (default_acl) { |
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err = __reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT, |
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default_acl); |
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posix_acl_release(default_acl); |
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} |
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if (acl) { |
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if (!err) |
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err = __reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS, |
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acl); |
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posix_acl_release(acl); |
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} |
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return err; |
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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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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 = 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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* 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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/* |
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* Called under i_mutex |
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*/ |
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int reiserfs_acl_chmod(struct inode *inode) |
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{ |
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if (IS_PRIVATE(inode)) |
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return 0; |
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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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return posix_acl_chmod(&init_user_ns, inode, inode->i_mode); |
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}
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