diff options
author | Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz> | 2011-05-08 20:42:54 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-05-09 09:04:23 -0700 |
commit | 7dd29d8d865efdb00c0542a5d2c87af8c52ea6c7 (patch) | |
tree | 71f404ed317e2d1b689af088ece1c32c3b1535c8 /fs/hpfs/hpfs_fn.h | |
parent | 637b424bf8747e50bab6648ab919632d6efd6c28 (diff) | |
download | linux-7dd29d8d865efdb00c0542a5d2c87af8c52ea6c7.tar.bz2 |
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 <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/hpfs/hpfs_fn.h')
-rw-r--r-- | fs/hpfs/hpfs_fn.h | 24 |
1 files changed, 15 insertions, 9 deletions
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)); } |