From 579aa9caf552c639fc78168db4cfe7ffcf00c3b3 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 22 Apr 2008 17:34:00 +1000 Subject: [XFS] shrink mrlock_t The writer field is not needed for non_DEBU builds so remove it. While we're at i also clean up the interface for is locked asserts to go through and xfs_iget.c helper with an interface like the xfs_ilock routines to isolated the XFS codebase from mrlock internals. That way we can kill mrlock_t entirely once rw_semaphores grow an islocked facility. Also remove unused flags to the ilock family of functions. SGI-PV: 976035 SGI-Modid: xfs-linux-melb:xfs-kern:30902a Signed-off-by: Christoph Hellwig Signed-off-by: Lachlan McIlroy --- fs/xfs/linux-2.6/mrlock.h | 60 +++++++++++++++++++---------------------------- 1 file changed, 24 insertions(+), 36 deletions(-) (limited to 'fs/xfs/linux-2.6/mrlock.h') diff --git a/fs/xfs/linux-2.6/mrlock.h b/fs/xfs/linux-2.6/mrlock.h index c110bb002665..ff6a19873e5c 100644 --- a/fs/xfs/linux-2.6/mrlock.h +++ b/fs/xfs/linux-2.6/mrlock.h @@ -20,29 +20,24 @@ #include -enum { MR_NONE, MR_ACCESS, MR_UPDATE }; - typedef struct { struct rw_semaphore mr_lock; +#ifdef DEBUG int mr_writer; +#endif } mrlock_t; +#ifdef DEBUG #define mrinit(mrp, name) \ do { (mrp)->mr_writer = 0; init_rwsem(&(mrp)->mr_lock); } while (0) +#else +#define mrinit(mrp, name) \ + do { init_rwsem(&(mrp)->mr_lock); } while (0) +#endif + #define mrlock_init(mrp, t,n,s) mrinit(mrp, n) #define mrfree(mrp) do { } while (0) -static inline void mraccess(mrlock_t *mrp) -{ - down_read(&mrp->mr_lock); -} - -static inline void mrupdate(mrlock_t *mrp) -{ - down_write(&mrp->mr_lock); - mrp->mr_writer = 1; -} - static inline void mraccess_nested(mrlock_t *mrp, int subclass) { down_read_nested(&mrp->mr_lock, subclass); @@ -51,10 +46,11 @@ static inline void mraccess_nested(mrlock_t *mrp, int subclass) static inline void mrupdate_nested(mrlock_t *mrp, int subclass) { down_write_nested(&mrp->mr_lock, subclass); +#ifdef DEBUG mrp->mr_writer = 1; +#endif } - static inline int mrtryaccess(mrlock_t *mrp) { return down_read_trylock(&mrp->mr_lock); @@ -64,39 +60,31 @@ static inline int mrtryupdate(mrlock_t *mrp) { if (!down_write_trylock(&mrp->mr_lock)) return 0; +#ifdef DEBUG mrp->mr_writer = 1; +#endif return 1; } -static inline void mrunlock(mrlock_t *mrp) +static inline void mrunlock_excl(mrlock_t *mrp) { - if (mrp->mr_writer) { - mrp->mr_writer = 0; - up_write(&mrp->mr_lock); - } else { - up_read(&mrp->mr_lock); - } +#ifdef DEBUG + mrp->mr_writer = 0; +#endif + up_write(&mrp->mr_lock); } -static inline void mrdemote(mrlock_t *mrp) +static inline void mrunlock_shared(mrlock_t *mrp) { - mrp->mr_writer = 0; - downgrade_write(&mrp->mr_lock); + up_read(&mrp->mr_lock); } -#ifdef DEBUG -/* - * Debug-only routine, without some platform-specific asm code, we can - * now only answer requests regarding whether we hold the lock for write - * (reader state is outside our visibility, we only track writer state). - * Note: means !ismrlocked would give false positives, so don't do that. - */ -static inline int ismrlocked(mrlock_t *mrp, int type) +static inline void mrdemote(mrlock_t *mrp) { - if (mrp && type == MR_UPDATE) - return mrp->mr_writer; - return 1; -} +#ifdef DEBUG + mrp->mr_writer = 0; #endif + downgrade_write(&mrp->mr_lock); +} #endif /* __XFS_SUPPORT_MRLOCK_H__ */ -- cgit