[PATCH] v9fs: readlink extended mode check
LANL reported some issues with random crashes during mount of legacy protocol
servers (9P2000 versus 9P2000.u) -- crash was always happening in readlink
(which should never happen in legacy mode). Added some sanity conditionals to
the get_inode code which should prevent the errors LANL was seeing. Code
tested benign through regression.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 36fff08..0c13fc6 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -44,6 +44,7 @@
#include "fid.h"
static struct inode_operations v9fs_dir_inode_operations;
+static struct inode_operations v9fs_dir_inode_operations_ext;
static struct inode_operations v9fs_file_inode_operations;
static struct inode_operations v9fs_symlink_inode_operations;
@@ -232,6 +233,7 @@
struct inode *v9fs_get_inode(struct super_block *sb, int mode)
{
struct inode *inode = NULL;
+ struct v9fs_session_info *v9ses = sb->s_fs_info;
dprintk(DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
@@ -250,6 +252,10 @@
case S_IFBLK:
case S_IFCHR:
case S_IFSOCK:
+ if(!v9ses->extended) {
+ dprintk(DEBUG_ERROR, "special files without extended mode\n");
+ return ERR_PTR(-EINVAL);
+ }
init_special_inode(inode, inode->i_mode,
inode->i_rdev);
break;
@@ -257,14 +263,21 @@
inode->i_op = &v9fs_file_inode_operations;
inode->i_fop = &v9fs_file_operations;
break;
+ case S_IFLNK:
+ if(!v9ses->extended) {
+ dprintk(DEBUG_ERROR, "extended modes used w/o 9P2000.u\n");
+ return ERR_PTR(-EINVAL);
+ }
+ inode->i_op = &v9fs_symlink_inode_operations;
+ break;
case S_IFDIR:
inode->i_nlink++;
- inode->i_op = &v9fs_dir_inode_operations;
+ if(v9ses->extended)
+ inode->i_op = &v9fs_dir_inode_operations_ext;
+ else
+ inode->i_op = &v9fs_dir_inode_operations;
inode->i_fop = &v9fs_dir_operations;
break;
- case S_IFLNK:
- inode->i_op = &v9fs_symlink_inode_operations;
- break;
default:
dprintk(DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
mode, mode & S_IFMT);
@@ -1284,7 +1297,7 @@
return retval;
}
-static struct inode_operations v9fs_dir_inode_operations = {
+static struct inode_operations v9fs_dir_inode_operations_ext = {
.create = v9fs_vfs_create,
.lookup = v9fs_vfs_lookup,
.symlink = v9fs_vfs_symlink,
@@ -1299,6 +1312,18 @@
.setattr = v9fs_vfs_setattr,
};
+static struct inode_operations v9fs_dir_inode_operations = {
+ .create = v9fs_vfs_create,
+ .lookup = v9fs_vfs_lookup,
+ .unlink = v9fs_vfs_unlink,
+ .mkdir = v9fs_vfs_mkdir,
+ .rmdir = v9fs_vfs_rmdir,
+ .mknod = v9fs_vfs_mknod,
+ .rename = v9fs_vfs_rename,
+ .getattr = v9fs_vfs_getattr,
+ .setattr = v9fs_vfs_setattr,
+};
+
static struct inode_operations v9fs_file_inode_operations = {
.getattr = v9fs_vfs_getattr,
.setattr = v9fs_vfs_setattr,