[PATCH 2/7] vfs: inode_change_ok have to perform all necessery checks

[Dmitry Monakhov]

Usually this is the only function which called before inode
attributes manipulation. In fact inode_change_ok() performs only
posix checks. But it new_size check is also important. Otherwise
we mail fail in very late stage.

Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxxx>
---
 fs/attr.c          |   19 +++++++++++++++++--
 include/linux/fs.h |    3 ++-
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/fs/attr.c b/fs/attr.c
index b1cc391..cc2a801 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -18,7 +18,7 @@
 /* Taken over from the old code... */
 
 /* POSIX UID/GID verification for setting inode attributes. */
-int inode_change_ok(const struct inode *inode, struct iattr *attr)
+int inode_change_posix_ok(const struct inode *inode, struct iattr *attr)
 {
 	int retval = -EPERM;
 	unsigned int ia_valid = attr->ia_valid;
@@ -60,7 +60,7 @@ fine:
 error:
 	return retval;
 }
-EXPORT_SYMBOL(inode_change_ok);
+EXPORT_SYMBOL(inode_change_posix_ok);
 
 /**
  * inode_newsize_ok - may this inode be truncated to a given size
@@ -105,6 +105,21 @@ out_big:
 }
 EXPORT_SYMBOL(inode_newsize_ok);
 
+/*
+ * General verification for setting inode attributes.
+ */
+int inode_change_ok(const struct inode *inode, struct iattr *attr)
+{
+	int ret;
+	ret = inode_change_posix_ok(inode, attr);
+	if (ret)
+		return ret;
+	if (attr->ia_valid & ATTR_SIZE)
+		ret = inode_newsize_ok(inode, attr->ia_size);
+	return ret;
+}
+EXPORT_SYMBOL(inode_change_ok);
+
 void __inode_setattr(struct inode * inode, struct iattr * attr)
 {
 	unsigned int ia_valid = attr->ia_valid;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 18b7be8..eee26ea 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2371,8 +2371,9 @@ extern int buffer_migrate_page(struct address_space *,
 #define buffer_migrate_page NULL
 #endif
 
-extern int inode_change_ok(const struct inode *, struct iattr *);
+extern int inode_change_posix_ok(const struct inode *, struct iattr *);
 extern int inode_newsize_ok(const struct inode *, loff_t offset);
+extern int inode_change_ok(const struct inode *, struct iattr *);
 extern void __inode_setattr(struct inode *, struct iattr *);
 extern int __must_check inode_setattr(struct inode *, struct iattr *);
 
-- 
1.6.6

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