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/xfs_iget.c | 140 +++++++++++++++++++++++++++++------------------------- 1 file changed, 76 insertions(+), 64 deletions(-) (limited to 'fs/xfs/xfs_iget.c') diff --git a/fs/xfs/xfs_iget.c b/fs/xfs/xfs_iget.c index e657c51..b07604b 100644 --- a/fs/xfs/xfs_iget.c +++ b/fs/xfs/xfs_iget.c @@ -593,8 +593,9 @@ xfs_iunlock_map_shared( * XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL */ void -xfs_ilock(xfs_inode_t *ip, - uint lock_flags) +xfs_ilock( + xfs_inode_t *ip, + uint lock_flags) { /* * You can't set both SHARED and EXCL for the same lock, @@ -607,16 +608,16 @@ xfs_ilock(xfs_inode_t *ip, (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)); ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0); - if (lock_flags & XFS_IOLOCK_EXCL) { + if (lock_flags & XFS_IOLOCK_EXCL) mrupdate_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags)); - } else if (lock_flags & XFS_IOLOCK_SHARED) { + else if (lock_flags & XFS_IOLOCK_SHARED) mraccess_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags)); - } - if (lock_flags & XFS_ILOCK_EXCL) { + + if (lock_flags & XFS_ILOCK_EXCL) mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags)); - } else if (lock_flags & XFS_ILOCK_SHARED) { + else if (lock_flags & XFS_ILOCK_SHARED) mraccess_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags)); - } + xfs_ilock_trace(ip, 1, lock_flags, (inst_t *)__return_address); } @@ -631,15 +632,12 @@ xfs_ilock(xfs_inode_t *ip, * lock_flags -- this parameter indicates the inode's locks to be * to be locked. See the comment for xfs_ilock() for a list * of valid values. - * */ int -xfs_ilock_nowait(xfs_inode_t *ip, - uint lock_flags) +xfs_ilock_nowait( + xfs_inode_t *ip, + uint lock_flags) { - int iolocked; - int ilocked; - /* * You can't set both SHARED and EXCL for the same lock, * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED, @@ -651,37 +649,30 @@ xfs_ilock_nowait(xfs_inode_t *ip, (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)); ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0); - iolocked = 0; if (lock_flags & XFS_IOLOCK_EXCL) { - iolocked = mrtryupdate(&ip->i_iolock); - if (!iolocked) { - return 0; - } + if (!mrtryupdate(&ip->i_iolock)) + goto out; } else if (lock_flags & XFS_IOLOCK_SHARED) { - iolocked = mrtryaccess(&ip->i_iolock); - if (!iolocked) { - return 0; - } + if (!mrtryaccess(&ip->i_iolock)) + goto out; } if (lock_flags & XFS_ILOCK_EXCL) { - ilocked = mrtryupdate(&ip->i_lock); - if (!ilocked) { - if (iolocked) { - mrunlock(&ip->i_iolock); - } - return 0; - } + if (!mrtryupdate(&ip->i_lock)) + goto out_undo_iolock; } else if (lock_flags & XFS_ILOCK_SHARED) { - ilocked = mrtryaccess(&ip->i_lock); - if (!ilocked) { - if (iolocked) { - mrunlock(&ip->i_iolock); - } - return 0; - } + if (!mrtryaccess(&ip->i_lock)) + goto out_undo_iolock; } xfs_ilock_trace(ip, 2, lock_flags, (inst_t *)__return_address); return 1; + + out_undo_iolock: + if (lock_flags & XFS_IOLOCK_EXCL) + mrunlock_excl(&ip->i_iolock); + else if (lock_flags & XFS_IOLOCK_SHARED) + mrunlock_shared(&ip->i_iolock); + out: + return 0; } /* @@ -697,8 +688,9 @@ xfs_ilock_nowait(xfs_inode_t *ip, * */ void -xfs_iunlock(xfs_inode_t *ip, - uint lock_flags) +xfs_iunlock( + xfs_inode_t *ip, + uint lock_flags) { /* * You can't set both SHARED and EXCL for the same lock, @@ -713,31 +705,25 @@ xfs_iunlock(xfs_inode_t *ip, XFS_LOCK_DEP_MASK)) == 0); ASSERT(lock_flags != 0); - if (lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) { - ASSERT(!(lock_flags & XFS_IOLOCK_SHARED) || - (ismrlocked(&ip->i_iolock, MR_ACCESS))); - ASSERT(!(lock_flags & XFS_IOLOCK_EXCL) || - (ismrlocked(&ip->i_iolock, MR_UPDATE))); - mrunlock(&ip->i_iolock); - } + if (lock_flags & XFS_IOLOCK_EXCL) + mrunlock_excl(&ip->i_iolock); + else if (lock_flags & XFS_IOLOCK_SHARED) + mrunlock_shared(&ip->i_iolock); - if (lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) { - ASSERT(!(lock_flags & XFS_ILOCK_SHARED) || - (ismrlocked(&ip->i_lock, MR_ACCESS))); - ASSERT(!(lock_flags & XFS_ILOCK_EXCL) || - (ismrlocked(&ip->i_lock, MR_UPDATE))); - mrunlock(&ip->i_lock); + if (lock_flags & XFS_ILOCK_EXCL) + mrunlock_excl(&ip->i_lock); + else if (lock_flags & XFS_ILOCK_SHARED) + mrunlock_shared(&ip->i_lock); + if ((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) && + !(lock_flags & XFS_IUNLOCK_NONOTIFY) && ip->i_itemp) { /* * Let the AIL know that this item has been unlocked in case * it is in the AIL and anyone is waiting on it. Don't do * this if the caller has asked us not to. */ - if (!(lock_flags & XFS_IUNLOCK_NONOTIFY) && - ip->i_itemp != NULL) { - xfs_trans_unlocked_item(ip->i_mount, - (xfs_log_item_t*)(ip->i_itemp)); - } + xfs_trans_unlocked_item(ip->i_mount, + (xfs_log_item_t*)(ip->i_itemp)); } xfs_ilock_trace(ip, 3, lock_flags, (inst_t *)__return_address); } @@ -747,21 +733,47 @@ xfs_iunlock(xfs_inode_t *ip, * if it is being demoted. */ void -xfs_ilock_demote(xfs_inode_t *ip, - uint lock_flags) +xfs_ilock_demote( + xfs_inode_t *ip, + uint lock_flags) { ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL)); ASSERT((lock_flags & ~(XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL)) == 0); - if (lock_flags & XFS_ILOCK_EXCL) { - ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE)); + if (lock_flags & XFS_ILOCK_EXCL) mrdemote(&ip->i_lock); - } - if (lock_flags & XFS_IOLOCK_EXCL) { - ASSERT(ismrlocked(&ip->i_iolock, MR_UPDATE)); + if (lock_flags & XFS_IOLOCK_EXCL) mrdemote(&ip->i_iolock); +} + +#ifdef DEBUG +/* + * Debug-only routine, without additional rw_semaphore APIs, 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: this means !xfs_isilocked would give false positives, so don't do that. + */ +int +xfs_isilocked( + xfs_inode_t *ip, + uint lock_flags) +{ + if ((lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) == + XFS_ILOCK_EXCL) { + if (!ip->i_lock.mr_writer) + return 0; } + + if ((lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) == + XFS_IOLOCK_EXCL) { + if (!ip->i_iolock.mr_writer) + return 0; + } + + return 1; } +#endif /* * The following three routines simply manage the i_flock -- cgit v1.1