Hi Linus,
I think that the check for inode->i_op == NULL in various
vfs_XXX() functions is bogus, i.e. if it is NULL then it must be a bug in
some filesystem's ->read_inode() method and therefore, instead of
returning error to userspace we should immediately panic, since it is a
kernel bug.
The patch below does just that -- i.e. converts them into BUG()s. This
also has the added advantage that if we are 100% confident in our
filesystems (or kernel in general) we can compile with #define BUG /* */
and get a smaller/faster kernel.
Regards,
Tigran
diff -urN -X dontdiff linux/fs/attr.c BUG/fs/attr.c
--- linux/fs/attr.c Mon Oct 16 21:00:53 2000
+++ BUG/fs/attr.c Wed Nov 8 15:43:35 2000
@@ -113,6 +113,9 @@
if (!inode)
BUG();
+ if (!inode->i_op)
+ BUG();
+
attr->ia_ctime = now;
if (!(ia_valid & ATTR_ATIME_SET))
attr->ia_atime = now;
@@ -120,7 +123,7 @@
attr->ia_mtime = now;
lock_kernel();
- 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);
diff -urN -X dontdiff linux/fs/namei.c BUG/fs/namei.c
--- linux/fs/namei.c Fri Sep 22 22:21:18 2000
+++ BUG/fs/namei.c Wed Nov 8 15:43:10 2000
@@ -156,7 +156,10 @@
{
int mode = inode->i_mode;
- if (inode->i_op && inode->i_op->permission) {
+ if (!inode->i_op)
+ BUG();
+
+ if (inode->i_op->permission) {
int retval;
lock_kernel();
retval = inode->i_op->permission(inode, mask);
@@ -898,13 +901,16 @@
mode &= S_IALLUGO & ~current->fs->umask;
mode |= S_IFREG;
+ if (!dir->i_op)
+ BUG();
+
down(&dir->i_zombie);
error = may_create(dir, dentry);
if (error)
goto exit_lock;
error = -EACCES; /* shouldn't it be ENOSYS? */
- if (!dir->i_op || !dir->i_op->create)
+ if (!dir->i_op->create)
goto exit_lock;
DQUOT_INIT(dir);
@@ -1173,6 +1179,9 @@
{
int error = -EPERM;
+ if (!dir->i_op)
+ BUG();
+
mode &= ~current->fs->umask;
down(&dir->i_zombie);
@@ -1184,7 +1193,7 @@
goto exit_lock;
error = -EPERM;
- if (!dir->i_op || !dir->i_op->mknod)
+ if (!dir->i_op->mknod)
goto exit_lock;
DQUOT_INIT(dir);
@@ -1245,13 +1254,16 @@
{
int error;
+ if (!dir->i_op)
+ BUG();
+
down(&dir->i_zombie);
error = may_create(dir, dentry);
if (error)
goto exit_lock;
error = -EPERM;
- if (!dir->i_op || !dir->i_op->mkdir)
+ if (!dir->i_op->mkdir)
goto exit_lock;
DQUOT_INIT(dir);
@@ -1328,12 +1340,15 @@
int vfs_rmdir(struct inode *dir, struct dentry *dentry)
{
int error;
+
+ if (!dir->i_op)
+ BUG();
error = may_delete(dir, dentry, 1);
if (error)
return error;
-
- if (!dir->i_op || !dir->i_op->rmdir)
+
+ if (!dir->i_op->rmdir)
return -EPERM;
DQUOT_INIT(dir);
@@ -1404,11 +1419,14 @@
{
int error;
+ if (!dir->i_op)
+ BUG();
+
down(&dir->i_zombie);
error = may_delete(dir, dentry, 0);
if (!error) {
error = -EPERM;
- if (dir->i_op && dir->i_op->unlink) {
+ if (dir->i_op->unlink) {
DQUOT_INIT(dir);
if (d_mountpoint(dentry))
error = -EBUSY;
@@ -1474,13 +1492,16 @@
{
int error;
+ if (!dir->i_op)
+ BUG();
+
down(&dir->i_zombie);
error = may_create(dir, dentry);
if (error)
goto exit_lock;
error = -EPERM;
- if (!dir->i_op || !dir->i_op->symlink)
+ if (!dir->i_op->symlink)
goto exit_lock;
DQUOT_INIT(dir);
@@ -1534,6 +1555,9 @@
struct inode *inode;
int error;
+ if (!dir->i_op)
+ BUG();
+
down(&dir->i_zombie);
error = -ENOENT;
inode = old_dentry->d_inode;
@@ -1554,7 +1578,7 @@
error = -EPERM;
if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
goto exit_lock;
- if (!dir->i_op || !dir->i_op->link)
+ if (!dir->i_op->link)
goto exit_lock;
DQUOT_INIT(dir);
@@ -1658,6 +1682,9 @@
if (old_dentry->d_inode == new_dentry->d_inode)
return 0;
+ if (!old_dir->i_op)
+ BUG();
+
error = may_delete(old_dir, old_dentry, 1);
if (error)
return error;
@@ -1672,7 +1699,7 @@
if (error)
return error;
- if (!old_dir->i_op || !old_dir->i_op->rename)
+ if (!old_dir->i_op->rename)
return -EPERM;
/*
@@ -1734,6 +1761,9 @@
if (old_dentry->d_inode == new_dentry->d_inode)
return 0;
+ if (!old_dir->i_op)
+ BUG();
+
error = may_delete(old_dir, old_dentry, 0);
if (error)
return error;
@@ -1748,7 +1778,7 @@
if (error)
return error;
- if (!old_dir->i_op || !old_dir->i_op->rename)
+ if (!old_dir->i_op->rename)
return -EPERM;
DQUOT_INIT(old_dir);
-
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This archive was generated by hypermail 2b29 : Wed Nov 15 2000 - 21:00:12 EST