new code in 2.5 VFS layer invokes notify_change to clear the suid and sgid
bits for every write request. notify_change needs to optimize out calls
to ->setattr that don't do anything, because for many network file
systems, an on-the-wire SETATTR request is generated for every ->setattr
call, resulting in unnecessary latency for NFS writes.
diff -ruN 05-nfsroot/fs/attr.c 06-setattr/fs/attr.c
--- 05-nfsroot/fs/attr.c Mon Nov 4 17:30:07 2002
+++ 06-setattr/fs/attr.c Thu Nov 7 17:31:37 2002
@@ -134,6 +134,7 @@
if (!(ia_valid & ATTR_MTIME_SET))
attr->ia_mtime = now;
if (ia_valid & ATTR_KILL_SUID) {
+ attr->ia_valid &= ~ATTR_KILL_SUID;
if (mode & S_ISUID) {
if (!(ia_valid & ATTR_MODE)) {
ia_valid = attr->ia_valid |= ATTR_MODE;
@@ -143,6 +144,7 @@
}
}
if (ia_valid & ATTR_KILL_SGID) {
+ attr->ia_valid &= ~ ATTR_KILL_SGID;
if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
if (!(ia_valid & ATTR_MODE)) {
ia_valid = attr->ia_valid |= ATTR_MODE;
@@ -151,6 +153,8 @@
attr->ia_mode &= ~S_ISGID;
}
}
+ if (!attr->ia_valid)
+ return 0;
if (inode->i_op && inode->i_op->setattr) {
error = security_ops->inode_setattr(dentry, attr);
-
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This archive was generated by hypermail 2b29 : Thu Nov 07 2002 - 22:00:50 EST