BKL: Remove BKL from ncpfs

Dozen of changes in ncpfs to provide some locking other than BKL.

In readdir cache unlock and mark complete first page as last operation,
so it can be used for synchronization, as code intended.

When updating dentry name on case insensitive filesystems do at least
some basic locking...

Hold i_mutex when updating inode fields.

Push some ncp_conn_is_valid down to ncp_request.  Connection can become
invalid at any moment, and fewer error code paths to test the better.

Use i_size_{read,write} to modify file size.

Set inode's backing_dev_info as ncpfs has its own special bdi.

In ioctl unbreak ioctls invoked on filesystem mounted 'ro' - tests are
for inode writeable or owner match, but were turned to filesystem
writeable and inode writeable or owner match.  Also collect all permission
checks in single place.

Add some locking, and remove comments saying that it would be cool to
add some locks to the code.

Constify some pointers.

Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 24 insertions, 17 deletions

diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c
index b4de38cf49f..5f4e58d93fd 100644
--- a/fs/ncpfs/inode.c
+++ b/fs/ncpfs/inode.c
@@ -139,7 +139,7 @@ static void ncp_update_dates(struct inode *inode, struct nw_info_struct *nwi)
 		inode->i_mode = nwi->nfs.mode;
 	}
 
-	inode->i_blocks = (inode->i_size + NCP_BLOCK_SIZE - 1) >> NCP_BLOCK_SHIFT;
+	inode->i_blocks = (i_size_read(inode) + NCP_BLOCK_SIZE - 1) >> NCP_BLOCK_SHIFT;
 
 	inode->i_mtime.tv_sec = ncp_date_dos2unix(nwi->modifyTime, nwi->modifyDate);
 	inode->i_ctime.tv_sec = ncp_date_dos2unix(nwi->creationTime, nwi->creationDate);
@@ -158,18 +158,21 @@ static void ncp_update_attrs(struct inode *inode, struct ncp_entry_info *nwinfo)
 		inode->i_mode = server->m.dir_mode;
 		/* for directories dataStreamSize seems to be some
 		   Object ID ??? */
-		inode->i_size = NCP_BLOCK_SIZE;
+		i_size_write(inode, NCP_BLOCK_SIZE);
 	} else {
+		u32 size;
+
 		inode->i_mode = server->m.file_mode;
-		inode->i_size = le32_to_cpu(nwi->dataStreamSize);
+		size = le32_to_cpu(nwi->dataStreamSize);
+		i_size_write(inode, size);
 #ifdef CONFIG_NCPFS_EXTRAS
 		if ((server->m.flags & (NCP_MOUNT_EXTRAS|NCP_MOUNT_SYMLINKS)) 
 		 && (nwi->attributes & aSHARED)) {
 			switch (nwi->attributes & (aHIDDEN|aSYSTEM)) {
 				case aHIDDEN:
 					if (server->m.flags & NCP_MOUNT_SYMLINKS) {
-						if (/* (inode->i_size >= NCP_MIN_SYMLINK_SIZE)
-						 && */ (inode->i_size <= NCP_MAX_SYMLINK_SIZE)) {
+						if (/* (size >= NCP_MIN_SYMLINK_SIZE)
+						 && */ (size <= NCP_MAX_SYMLINK_SIZE)) {
 							inode->i_mode = (inode->i_mode & ~S_IFMT) | S_IFLNK;
 							NCP_FINFO(inode)->flags |= NCPI_KLUDGE_SYMLINK;
 							break;
@@ -208,7 +211,7 @@ void ncp_update_inode2(struct inode* inode, struct ncp_entry_info *nwinfo)
 }
 
 /*
- * Fill in the inode based on the ncp_entry_info structure.
+ * Fill in the inode based on the ncp_entry_info structure.  Used only for brand new inodes.
  */
 static void ncp_set_attr(struct inode *inode, struct ncp_entry_info *nwinfo)
 {
@@ -254,6 +257,7 @@ ncp_iget(struct super_block *sb, struct ncp_entry_info *info)
 	if (inode) {
 		atomic_set(&NCP_FINFO(inode)->opened, info->opened);
 
+		inode->i_mapping->backing_dev_info = sb->s_bdi;
 		inode->i_ino = info->ino;
 		ncp_set_attr(inode, info);
 		if (S_ISREG(inode->i_mode)) {
@@ -565,10 +569,12 @@ static int ncp_fill_super(struct super_block *sb, void *raw_data, int silent)
 /*	server->conn_status = 0;	*/
 /*	server->root_dentry = NULL;	*/
 /*	server->root_setuped = 0;	*/
+	mutex_init(&server->root_setup_lock);
 #ifdef CONFIG_NCPFS_PACKET_SIGNING
 /*	server->sign_wanted = 0;	*/
 /*	server->sign_active = 0;	*/
 #endif
+	init_rwsem(&server->auth_rwsem);
 	server->auth.auth_type = NCP_AUTH_NONE;
 /*	server->auth.object_name_len = 0;	*/
 /*	server->auth.object_name = NULL;	*/
@@ -593,7 +599,7 @@ static int ncp_fill_super(struct super_block *sb, void *raw_data, int silent)
 	server->nls_io = load_nls_default();
 #endif /* CONFIG_NCPFS_NLS */
 
-	server->dentry_ttl = 0;	/* no caching */
+	atomic_set(&server->dentry_ttl, 0);	/* no caching */
 
 	INIT_LIST_HEAD(&server->tx.requests);
 	mutex_init(&server->rcv.creq_mutex);
@@ -658,8 +664,10 @@ static int ncp_fill_super(struct super_block *sb, void *raw_data, int silent)
 				goto out_disconnect;
 			}
 		}
+		ncp_lock_server(server);
 		if (options & 2)
 			server->sign_wanted = 1;
+		ncp_unlock_server(server);
 	}
 	else 
 #endif	/* CONFIG_NCPFS_PACKET_SIGNING */
@@ -720,6 +728,9 @@ out_nls:
 	unload_nls(server->nls_io);
 	unload_nls(server->nls_vol);
 #endif
+	mutex_destroy(&server->rcv.creq_mutex);
+	mutex_destroy(&server->root_setup_lock);
+	mutex_destroy(&server->mutex);
 out_fput2:
 	if (server->info_filp)
 		fput(server->info_filp);
@@ -743,8 +754,6 @@ static void ncp_put_super(struct super_block *sb)
 {
 	struct ncp_server *server = NCP_SBP(sb);
 
-	lock_kernel();
-
 	ncp_lock_server(server);
 	ncp_disconnect(server);
 	ncp_unlock_server(server);
@@ -756,6 +765,9 @@ static void ncp_put_super(struct super_block *sb)
 	unload_nls(server->nls_vol);
 	unload_nls(server->nls_io);
 #endif /* CONFIG_NCPFS_NLS */
+	mutex_destroy(&server->rcv.creq_mutex);
+	mutex_destroy(&server->root_setup_lock);
+	mutex_destroy(&server->mutex);
 
 	if (server->info_filp)
 		fput(server->info_filp);
@@ -771,8 +783,6 @@ static void ncp_put_super(struct super_block *sb)
 	vfree(server->packet);
 	sb->s_fs_info = NULL;
 	kfree(server);
-
-	unlock_kernel();
 }
 
 static int ncp_statfs(struct dentry *dentry, struct kstatfs *buf)
@@ -851,10 +861,8 @@ int ncp_notify_change(struct dentry *dentry, struct iattr *attr)
 
 	result = -EIO;
 
-	lock_kernel();	
-
 	server = NCP_SERVER(inode);
-	if ((!server) || !ncp_conn_valid(server))
+	if (!server)	/* How this could happen? */
 		goto out;
 
 	/* ageing the dentry to force validation */
@@ -981,8 +989,6 @@ int ncp_notify_change(struct dentry *dentry, struct iattr *attr)
 		result = ncp_modify_file_or_subdir_dos_info(NCP_SERVER(inode),
 				      inode, info_mask, &info);
 		if (result != 0) {
-			result = -EACCES;
-
 			if (info_mask == (DM_CREATE_TIME | DM_CREATE_DATE)) {
 				/* NetWare seems not to allow this. I
 				   do not know why. So, just tell the
@@ -1005,7 +1011,8 @@ int ncp_notify_change(struct dentry *dentry, struct iattr *attr)
 	mark_inode_dirty(inode);
 
 out:
-	unlock_kernel();
+	if (result > 0)
+		result = -EACCES;
 	return result;
 }