Fixed MTP to work with TWRP

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);
+}