[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 <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
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_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_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 @@
* 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_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 @@
*
*/
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_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);
}
@@ -747,22 +733,48 @@
* 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
* semaphore embedded in the inode. This semaphore synchronizes
