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Diffstat (limited to 'kernel/fs/reiserfs/xattr_acl.c')
-rw-r--r--kernel/fs/reiserfs/xattr_acl.c407
1 files changed, 407 insertions, 0 deletions
diff --git a/kernel/fs/reiserfs/xattr_acl.c b/kernel/fs/reiserfs/xattr_acl.c
new file mode 100644
index 000000000..4b34b9dc0
--- /dev/null
+++ b/kernel/fs/reiserfs/xattr_acl.c
@@ -0,0 +1,407 @@
+#include <linux/capability.h>
+#include <linux/fs.h>
+#include <linux/posix_acl.h>
+#include "reiserfs.h"
+#include <linux/errno.h>
+#include <linux/pagemap.h>
+#include <linux/xattr.h>
+#include <linux/slab.h>
+#include <linux/posix_acl_xattr.h>
+#include "xattr.h"
+#include "acl.h"
+#include <linux/uaccess.h>
+
+static int __reiserfs_set_acl(struct reiserfs_transaction_handle *th,
+ struct inode *inode, int type,
+ struct posix_acl *acl);
+
+
+int
+reiserfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+ int error, error2;
+ struct reiserfs_transaction_handle th;
+ size_t jcreate_blocks;
+ int size = acl ? posix_acl_xattr_size(acl->a_count) : 0;
+
+
+ /*
+ * Pessimism: We can't assume that anything from the xattr root up
+ * has been created.
+ */
+
+ jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) +
+ reiserfs_xattr_nblocks(inode, size) * 2;
+
+ reiserfs_write_lock(inode->i_sb);
+ error = journal_begin(&th, inode->i_sb, jcreate_blocks);
+ reiserfs_write_unlock(inode->i_sb);
+ if (error == 0) {
+ error = __reiserfs_set_acl(&th, inode, type, acl);
+ reiserfs_write_lock(inode->i_sb);
+ error2 = journal_end(&th);
+ reiserfs_write_unlock(inode->i_sb);
+ if (error2)
+ error = error2;
+ }
+
+ return error;
+}
+
+/*
+ * Convert from filesystem to in-memory representation.
+ */
+static struct posix_acl *reiserfs_posix_acl_from_disk(const void *value, size_t size)
+{
+ const char *end = (char *)value + size;
+ int n, count;
+ struct posix_acl *acl;
+
+ if (!value)
+ return NULL;
+ if (size < sizeof(reiserfs_acl_header))
+ return ERR_PTR(-EINVAL);
+ if (((reiserfs_acl_header *) value)->a_version !=
+ cpu_to_le32(REISERFS_ACL_VERSION))
+ return ERR_PTR(-EINVAL);
+ value = (char *)value + sizeof(reiserfs_acl_header);
+ count = reiserfs_acl_count(size);
+ if (count < 0)
+ return ERR_PTR(-EINVAL);
+ if (count == 0)
+ return NULL;
+ acl = posix_acl_alloc(count, GFP_NOFS);
+ if (!acl)
+ return ERR_PTR(-ENOMEM);
+ for (n = 0; n < count; n++) {
+ reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value;
+ if ((char *)value + sizeof(reiserfs_acl_entry_short) > end)
+ goto fail;
+ acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
+ acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
+ switch (acl->a_entries[n].e_tag) {
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ value = (char *)value +
+ sizeof(reiserfs_acl_entry_short);
+ break;
+
+ case ACL_USER:
+ value = (char *)value + sizeof(reiserfs_acl_entry);
+ if ((char *)value > end)
+ goto fail;
+ acl->a_entries[n].e_uid =
+ make_kuid(&init_user_ns,
+ le32_to_cpu(entry->e_id));
+ break;
+ case ACL_GROUP:
+ value = (char *)value + sizeof(reiserfs_acl_entry);
+ if ((char *)value > end)
+ goto fail;
+ acl->a_entries[n].e_gid =
+ make_kgid(&init_user_ns,
+ le32_to_cpu(entry->e_id));
+ break;
+
+ default:
+ goto fail;
+ }
+ }
+ if (value != end)
+ goto fail;
+ return acl;
+
+fail:
+ posix_acl_release(acl);
+ return ERR_PTR(-EINVAL);
+}
+
+/*
+ * Convert from in-memory to filesystem representation.
+ */
+static void *reiserfs_posix_acl_to_disk(const struct posix_acl *acl, size_t * size)
+{
+ reiserfs_acl_header *ext_acl;
+ char *e;
+ int n;
+
+ *size = reiserfs_acl_size(acl->a_count);
+ ext_acl = kmalloc(sizeof(reiserfs_acl_header) +
+ acl->a_count *
+ sizeof(reiserfs_acl_entry),
+ GFP_NOFS);
+ if (!ext_acl)
+ return ERR_PTR(-ENOMEM);
+ ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION);
+ e = (char *)ext_acl + sizeof(reiserfs_acl_header);
+ for (n = 0; n < acl->a_count; n++) {
+ const struct posix_acl_entry *acl_e = &acl->a_entries[n];
+ reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e;
+ entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
+ entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
+ switch (acl->a_entries[n].e_tag) {
+ case ACL_USER:
+ entry->e_id = cpu_to_le32(
+ from_kuid(&init_user_ns, acl_e->e_uid));
+ e += sizeof(reiserfs_acl_entry);
+ break;
+ case ACL_GROUP:
+ entry->e_id = cpu_to_le32(
+ from_kgid(&init_user_ns, acl_e->e_gid));
+ e += sizeof(reiserfs_acl_entry);
+ break;
+
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ e += sizeof(reiserfs_acl_entry_short);
+ break;
+
+ default:
+ goto fail;
+ }
+ }
+ return (char *)ext_acl;
+
+fail:
+ kfree(ext_acl);
+ return ERR_PTR(-EINVAL);
+}
+
+/*
+ * Inode operation get_posix_acl().
+ *
+ * inode->i_mutex: down
+ * BKL held [before 2.5.x]
+ */
+struct posix_acl *reiserfs_get_acl(struct inode *inode, int type)
+{
+ char *name, *value;
+ struct posix_acl *acl;
+ int size;
+ int retval;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ name = POSIX_ACL_XATTR_ACCESS;
+ break;
+ case ACL_TYPE_DEFAULT:
+ name = POSIX_ACL_XATTR_DEFAULT;
+ break;
+ default:
+ BUG();
+ }
+
+ size = reiserfs_xattr_get(inode, name, NULL, 0);
+ if (size < 0) {
+ if (size == -ENODATA || size == -ENOSYS) {
+ set_cached_acl(inode, type, NULL);
+ return NULL;
+ }
+ return ERR_PTR(size);
+ }
+
+ value = kmalloc(size, GFP_NOFS);
+ if (!value)
+ return ERR_PTR(-ENOMEM);
+
+ retval = reiserfs_xattr_get(inode, name, value, size);
+ if (retval == -ENODATA || retval == -ENOSYS) {
+ /*
+ * This shouldn't actually happen as it should have
+ * been caught above.. but just in case
+ */
+ acl = NULL;
+ } else if (retval < 0) {
+ acl = ERR_PTR(retval);
+ } else {
+ acl = reiserfs_posix_acl_from_disk(value, retval);
+ }
+ if (!IS_ERR(acl))
+ set_cached_acl(inode, type, acl);
+
+ kfree(value);
+ return acl;
+}
+
+/*
+ * Inode operation set_posix_acl().
+ *
+ * inode->i_mutex: down
+ * BKL held [before 2.5.x]
+ */
+static int
+__reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode,
+ int type, struct posix_acl *acl)
+{
+ char *name;
+ void *value = NULL;
+ size_t size = 0;
+ int error;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ name = POSIX_ACL_XATTR_ACCESS;
+ if (acl) {
+ error = posix_acl_equiv_mode(acl, &inode->i_mode);
+ if (error < 0)
+ return error;
+ else {
+ if (error == 0)
+ acl = NULL;
+ }
+ }
+ break;
+ case ACL_TYPE_DEFAULT:
+ name = POSIX_ACL_XATTR_DEFAULT;
+ if (!S_ISDIR(inode->i_mode))
+ return acl ? -EACCES : 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (acl) {
+ value = reiserfs_posix_acl_to_disk(acl, &size);
+ if (IS_ERR(value))
+ return (int)PTR_ERR(value);
+ }
+
+ error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0);
+
+ /*
+ * Ensure that the inode gets dirtied if we're only using
+ * the mode bits and an old ACL didn't exist. We don't need
+ * to check if the inode is hashed here since we won't get
+ * called by reiserfs_inherit_default_acl().
+ */
+ if (error == -ENODATA) {
+ error = 0;
+ if (type == ACL_TYPE_ACCESS) {
+ inode->i_ctime = CURRENT_TIME_SEC;
+ mark_inode_dirty(inode);
+ }
+ }
+
+ kfree(value);
+
+ if (!error)
+ set_cached_acl(inode, type, acl);
+
+ return error;
+}
+
+/*
+ * dir->i_mutex: locked,
+ * inode is new and not released into the wild yet
+ */
+int
+reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th,
+ struct inode *dir, struct dentry *dentry,
+ struct inode *inode)
+{
+ struct posix_acl *default_acl, *acl;
+ int err = 0;
+
+ /* ACLs only get applied to files and directories */
+ if (S_ISLNK(inode->i_mode))
+ return 0;
+
+ /*
+ * ACLs can only be used on "new" objects, so if it's an old object
+ * there is nothing to inherit from
+ */
+ if (get_inode_sd_version(dir) == STAT_DATA_V1)
+ goto apply_umask;
+
+ /*
+ * Don't apply ACLs to objects in the .reiserfs_priv tree.. This
+ * would be useless since permissions are ignored, and a pain because
+ * it introduces locking cycles
+ */
+ if (IS_PRIVATE(dir)) {
+ inode->i_flags |= S_PRIVATE;
+ goto apply_umask;
+ }
+
+ err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
+ if (err)
+ return err;
+
+ if (default_acl) {
+ err = __reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT,
+ default_acl);
+ posix_acl_release(default_acl);
+ }
+ if (acl) {
+ if (!err)
+ err = __reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS,
+ acl);
+ posix_acl_release(acl);
+ }
+
+ return err;
+
+apply_umask:
+ /* no ACL, apply umask */
+ inode->i_mode &= ~current_umask();
+ return err;
+}
+
+/* This is used to cache the default acl before a new object is created.
+ * The biggest reason for this is to get an idea of how many blocks will
+ * actually be required for the create operation if we must inherit an ACL.
+ * An ACL write can add up to 3 object creations and an additional file write
+ * so we'd prefer not to reserve that many blocks in the journal if we can.
+ * It also has the advantage of not loading the ACL with a transaction open,
+ * this may seem silly, but if the owner of the directory is doing the
+ * creation, the ACL may not be loaded since the permissions wouldn't require
+ * it.
+ * We return the number of blocks required for the transaction.
+ */
+int reiserfs_cache_default_acl(struct inode *inode)
+{
+ struct posix_acl *acl;
+ int nblocks = 0;
+
+ if (IS_PRIVATE(inode))
+ return 0;
+
+ acl = reiserfs_get_acl(inode, ACL_TYPE_DEFAULT);
+
+ if (acl && !IS_ERR(acl)) {
+ int size = reiserfs_acl_size(acl->a_count);
+
+ /* Other xattrs can be created during inode creation. We don't
+ * want to claim too many blocks, so we check to see if we
+ * we need to create the tree to the xattrs, and then we
+ * just want two files. */
+ nblocks = reiserfs_xattr_jcreate_nblocks(inode);
+ nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb);
+
+ REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
+
+ /* We need to account for writes + bitmaps for two files */
+ nblocks += reiserfs_xattr_nblocks(inode, size) * 4;
+ posix_acl_release(acl);
+ }
+
+ return nblocks;
+}
+
+/*
+ * Called under i_mutex
+ */
+int reiserfs_acl_chmod(struct inode *inode)
+{
+ if (IS_PRIVATE(inode))
+ return 0;
+ if (get_inode_sd_version(inode) == STAT_DATA_V1 ||
+ !reiserfs_posixacl(inode->i_sb))
+ return 0;
+
+ return posix_acl_chmod(inode, inode->i_mode);
+}