X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=fs%2Fattr.c;h=7ca41811afa1147ad764acbd1fe5b5957c883f5d;hb=b2117a39fa96cf4814e7cab8c11494149ba6f29d;hp=b4fa3b0aa59691ac4ca33d30e9afc308d5df98bd;hpb=7cc88fdcff3cc7f0d5d2384ffd7f6d4ce9a745f1;p=firefly-linux-kernel-4.4.55.git

diff --git a/fs/attr.c b/fs/attr.c
index b4fa3b0aa596..7ca41811afa1 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -14,35 +14,53 @@
 #include <linux/fcntl.h>
 #include <linux/security.h>
 
-/* Taken over from the old code... */
-
-/* POSIX UID/GID verification for setting inode attributes. */
+/**
+ * inode_change_ok - check if attribute changes to an inode are allowed
+ * @inode:	inode to check
+ * @attr:	attributes to change
+ *
+ * Check if we are allowed to change the attributes contained in @attr
+ * in the given inode.  This includes the normal unix access permission
+ * checks, as well as checks for rlimits and others.
+ *
+ * Should be called as the first thing in ->setattr implementations,
+ * possibly after taking additional locks.
+ */
 int inode_change_ok(const struct inode *inode, struct iattr *attr)
 {
-	int retval = -EPERM;
 	unsigned int ia_valid = attr->ia_valid;
 
+	/*
+	 * First check size constraints.  These can't be overriden using
+	 * ATTR_FORCE.
+	 */
+	if (ia_valid & ATTR_SIZE) {
+		int error = inode_newsize_ok(inode, attr->ia_size);
+		if (error)
+			return error;
+	}
+
 	/* If force is set do it anyway. */
 	if (ia_valid & ATTR_FORCE)
-		goto fine;
+		return 0;
 
 	/* Make sure a caller can chown. */
 	if ((ia_valid & ATTR_UID) &&
 	    (current_fsuid() != inode->i_uid ||
 	     attr->ia_uid != inode->i_uid) && !capable(CAP_CHOWN))
-		goto error;
+		return -EPERM;
 
 	/* Make sure caller can chgrp. */
 	if ((ia_valid & ATTR_GID) &&
 	    (current_fsuid() != inode->i_uid ||
 	    (!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid)) &&
 	    !capable(CAP_CHOWN))
-		goto error;
+		return -EPERM;
 
 	/* Make sure a caller can chmod. */
 	if (ia_valid & ATTR_MODE) {
 		if (!is_owner_or_cap(inode))
-			goto error;
+			return -EPERM;
 		/* Also check the setgid bit! */
 		if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid :
 				inode->i_gid) && !capable(CAP_FSETID))
@@ -52,12 +70,10 @@ int inode_change_ok(const struct inode *inode, struct iattr *attr)
 	/* Check for setting the inode time. */
 	if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) {
 		if (!is_owner_or_cap(inode))
-			goto error;
+			return -EPERM;
 	}
-fine:
-	retval = 0;
-error:
-	return retval;
+
+	return 0;
 }
 EXPORT_SYMBOL(inode_change_ok);
 
@@ -105,21 +121,21 @@ out_big:
 EXPORT_SYMBOL(inode_newsize_ok);
 
 /**
- * generic_setattr - copy simple metadata updates into the generic inode
+ * setattr_copy - copy simple metadata updates into the generic inode
  * @inode:	the inode to be updated
  * @attr:	the new attributes
  *
- * generic_setattr must be called with i_mutex held.
+ * setattr_copy must be called with i_mutex held.
  *
- * generic_setattr updates the inode's metadata with that specified
+ * setattr_copy updates the inode's metadata with that specified
  * in attr. Noticably missing is inode size update, which is more complex
- * as it requires pagecache updates. See simple_setsize.
+ * as it requires pagecache updates.
  *
  * The inode is not marked as dirty after this operation. The rationale is
  * that for "simple" filesystems, the struct inode is the inode storage.
  * The caller is free to mark the inode dirty afterwards if needed.
  */
-void generic_setattr(struct inode *inode, const struct iattr *attr)
+void setattr_copy(struct inode *inode, const struct iattr *attr)
 {
 	unsigned int ia_valid = attr->ia_valid;
 
@@ -144,32 +160,7 @@ void generic_setattr(struct inode *inode, const struct iattr *attr)
 		inode->i_mode = mode;
 	}
 }
-EXPORT_SYMBOL(generic_setattr);
-
-/*
- * note this function is deprecated, the new truncate sequence should be
- * used instead -- see eg. simple_setsize, generic_setattr.
- */
-int inode_setattr(struct inode *inode, const struct iattr *attr)
-{
-	unsigned int ia_valid = attr->ia_valid;
-
-	if (ia_valid & ATTR_SIZE &&
-	    attr->ia_size != i_size_read(inode)) {
-		int error;
-
-		error = vmtruncate(inode, attr->ia_size);
-		if (error)
-			return error;
-	}
-
-	generic_setattr(inode, attr);
-
-	mark_inode_dirty(inode);
-
-	return 0;
-}
-EXPORT_SYMBOL(inode_setattr);
+EXPORT_SYMBOL(setattr_copy);
 
 int notify_change(struct dentry * dentry, struct iattr * attr)
 {
@@ -237,13 +228,10 @@ int notify_change(struct dentry * dentry, struct iattr * attr)
 	if (ia_valid & ATTR_SIZE)
 		down_write(&dentry->d_inode->i_alloc_sem);
 
-	if (inode->i_op && inode->i_op->setattr) {
+	if (inode->i_op->setattr)
 		error = inode->i_op->setattr(dentry, attr);
-	} else {
-		error = inode_change_ok(inode, attr);
-		if (!error)
-			error = inode_setattr(inode, attr);
-	}
+	else
+		error = simple_setattr(dentry, attr);
 
 	if (ia_valid & ATTR_SIZE)
 		up_write(&dentry->d_inode->i_alloc_sem);