The patch titled
reiser4: decribe new atom locking and nested atom locks to lock validator
has been added to the -mm tree. Its filename is
reiser4-decribe-new-atom-locking-and-nested-atom-locks-to-lock-validator.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: reiser4: decribe new atom locking and nested atom locks to lock validator
From: Alexaner Zarochentsev <zam@xxxxxxxxxxx>
lock validator friendly locking of new atom in atom_begin_and_assign_to_txnh
and locking of two atoms.
Signed-off-by: Alexander Zarochentsev <zam@xxxxxxxxxxx>
Cc: Hans Reiser <reiser@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/reiser4/txnmgr.c | 20 +++++++++++---------
fs/reiser4/txnmgr.h | 15 +++++++++++++++
2 files changed, 26 insertions(+), 9 deletions(-)
diff -puN fs/reiser4/txnmgr.c~reiser4-decribe-new-atom-locking-and-nested-atom-locks-to-lock-validator fs/reiser4/txnmgr.c
--- a/fs/reiser4/txnmgr.c~reiser4-decribe-new-atom-locking-and-nested-atom-locks-to-lock-validator
+++ a/fs/reiser4/txnmgr.c
@@ -397,7 +397,7 @@ static void atom_init(txn_atom * atom)
INIT_LIST_HEAD(ATOM_OVRWR_LIST(atom));
INIT_LIST_HEAD(ATOM_WB_LIST(atom));
INIT_LIST_HEAD(&atom->inodes);
- spin_lock_init(&atom->alock);
+ spin_lock_init(&(atom->alock));
/* list of transaction handles */
INIT_LIST_HEAD(&atom->txnh_list);
/* link to transaction manager's list of atoms */
@@ -732,10 +732,12 @@ static int atom_begin_and_assign_to_txnh
assert("jmacd-17", atom_isclean(atom));
/*
- * do not use spin_lock_atom because we have broken lock ordering here
- * which is ok, as long as @atom is new and inaccessible for others.
+ * lock ordering is broken here. It is ok, as long as @atom is new
+ * and inaccessible for others. We can't use spin_lock_atom or
+ * spin_lock(&atom->alock) because they care about locking
+ * dependencies. spin_trylock_lock doesn't.
*/
- spin_lock(&(atom->alock));
+ check_me("", spin_trylock_atom(atom));
/* add atom to the end of transaction manager's list of atoms */
list_add_tail(&atom->atom_link, &mgr->atoms_list);
@@ -751,7 +753,7 @@ static int atom_begin_and_assign_to_txnh
atom->super = reiser4_get_current_sb();
capture_assign_txnh_nolock(atom, txnh);
- spin_unlock(&(atom->alock));
+ spin_unlock_atom(atom);
spin_unlock_txnh(txnh);
return -E_REPEAT;
@@ -2112,11 +2114,11 @@ static void fuse_not_fused_lock_owners(t
atomic_inc(&atomf->refcount);
spin_unlock_txnh(ctx->trans);
if (atomf > atomh) {
- spin_lock_atom(atomf);
+ spin_lock_atom_nested(atomf);
} else {
spin_unlock_atom(atomh);
spin_lock_atom(atomf);
- spin_lock_atom(atomh);
+ spin_lock_atom_nested(atomh);
}
if (atomh == atomf || !atom_isopen(atomh) || !atom_isopen(atomf)) {
release_two_atoms(atomf, atomh);
@@ -2794,10 +2796,10 @@ static void lock_two_atoms(txn_atom * on
/* lock the atom with lesser address first */
if (one < two) {
spin_lock_atom(one);
- spin_lock_atom(two);
+ spin_lock_atom_nested(two);
} else {
spin_lock_atom(two);
- spin_lock_atom(one);
+ spin_lock_atom_nested(one);
}
}
diff -puN fs/reiser4/txnmgr.h~reiser4-decribe-new-atom-locking-and-nested-atom-locks-to-lock-validator fs/reiser4/txnmgr.h
--- a/fs/reiser4/txnmgr.h~reiser4-decribe-new-atom-locking-and-nested-atom-locks-to-lock-validator
+++ a/fs/reiser4/txnmgr.h
@@ -503,6 +503,7 @@ static inline void spin_lock_atom(txn_at
{
/* check that spinlocks of lower priorities are not held */
assert("", (LOCK_CNT_NIL(spin_locked_txnh) &&
+ LOCK_CNT_NIL(spin_locked_atom) &&
LOCK_CNT_NIL(spin_locked_jnode) &&
LOCK_CNT_NIL(spin_locked_zlock) &&
LOCK_CNT_NIL(rw_locked_dk) &&
@@ -514,6 +515,20 @@ static inline void spin_lock_atom(txn_at
LOCK_CNT_INC(spin_locked);
}
+static inline void spin_lock_atom_nested(txn_atom *atom)
+{
+ assert("", (LOCK_CNT_NIL(spin_locked_txnh) &&
+ LOCK_CNT_NIL(spin_locked_jnode) &&
+ LOCK_CNT_NIL(spin_locked_zlock) &&
+ LOCK_CNT_NIL(rw_locked_dk) &&
+ LOCK_CNT_NIL(rw_locked_tree)));
+
+ spin_lock_nested(&(atom->alock), SINGLE_DEPTH_NESTING);
+
+ LOCK_CNT_INC(spin_locked_atom);
+ LOCK_CNT_INC(spin_locked);
+}
+
static inline int spin_trylock_atom(txn_atom *atom)
{
if (spin_trylock(&(atom->alock))) {
_
Patches currently in -mm which might be from zam@xxxxxxxxxxx are
reiser4-decribe-new-atom-locking-and-nested-atom-locks-to-lock-validator.patch
reiser4-use-generic-file-read.patch
reiser4-simplify-reading-of-partially-converted-files.patch
reiser4-use-page_offset.patch
reiser4-use-reiser4_gfp_mask_get-in-reiser4-inode-allocation.patch
reiser4-re-add-page_count-check-to-reiser4_releasepage.patch
reiser4-restore-fibmap-ioctl-support-for-packed-files.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
