From 7dd29d8d865efdb00c0542a5d2c87af8c52ea6c7 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Sun, 8 May 2011 20:42:54 +0200 Subject: HPFS: Introduce a global mutex and lock it on every callback from VFS. Introduce a global mutex and lock it on every callback from VFS. Performance doesn't matter, reviewing the whole code for locking correctness would be too complicated, so simply lock it all. Signed-off-by: Mikulas Patocka Signed-off-by: Linus Torvalds --- fs/hpfs/hpfs_fn.h | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) (limited to 'fs/hpfs/hpfs_fn.h') diff --git a/fs/hpfs/hpfs_fn.h b/fs/hpfs/hpfs_fn.h index c15adbca07ff..89a4714b44c7 100644 --- a/fs/hpfs/hpfs_fn.h +++ b/fs/hpfs/hpfs_fn.h @@ -63,6 +63,7 @@ struct hpfs_inode_info { }; struct hpfs_sb_info { + struct mutex hpfs_mutex; /* global hpfs lock */ ino_t sb_root; /* inode number of root dir */ unsigned sb_fs_size; /* file system size, sectors */ unsigned sb_bitmaps; /* sector number of bitmap list */ @@ -346,21 +347,26 @@ static inline time32_t gmt_to_local(struct super_block *s, time_t t) /* * Locking: * - * hpfs_lock() is a leftover from the big kernel lock. - * Right now, these functions are empty and only left - * for documentation purposes. The file system no longer - * works on SMP systems, so the lock is not needed - * any more. + * hpfs_lock() locks the whole filesystem. It must be taken + * on any method called by the VFS. * - * If someone is interested in making it work again, this - * would be the place to start by adding a per-superblock - * mutex and fixing all the bugs and performance issues - * caused by that. + * We don't do any per-file locking anymore, it is hard to + * review and HPFS is not performance-sensitive anyway. */ static inline void hpfs_lock(struct super_block *s) { + struct hpfs_sb_info *sbi = hpfs_sb(s); + mutex_lock(&sbi->hpfs_mutex); } static inline void hpfs_unlock(struct super_block *s) { + struct hpfs_sb_info *sbi = hpfs_sb(s); + mutex_unlock(&sbi->hpfs_mutex); +} + +static inline void hpfs_lock_assert(struct super_block *s) +{ + struct hpfs_sb_info *sbi = hpfs_sb(s); + WARN_ON(!mutex_is_locked(&sbi->hpfs_mutex)); } -- cgit v1.2.1