[patch 17/52] fs: dcache remove dcache_lock

npiggin
2010-06-24T03:16:57Z

[-- Attachment #1: fs-dcache_lock-remove.patch --]
[-- Type: text/plain, Size: 54005 bytes --]

dcache_lock no longer protects anything. remove it.

Signed-off-by: Nick Piggin <npiggin@suse.de>
---
Documentation/filesystems/Locking | 2
arch/powerpc/platforms/cell/spufs/inode.c | 5 -
drivers/infiniband/hw/ipath/ipath_fs.c | 6 -
drivers/infiniband/hw/qib/qib_fs.c | 3
drivers/staging/pohmelfs/path_entry.c | 2
drivers/usb/core/inode.c | 3
fs/affs/amigaffs.c | 2
fs/autofs4/autofs_i.h | 3
fs/autofs4/expire.c | 24 ++---
fs/autofs4/root.c | 14 +--
fs/autofs4/waitq.c | 7 -
fs/ceph/dir.c | 6 -
fs/ceph/inode.c | 4
fs/coda/cache.c | 2
fs/configfs/configfs_internal.h | 2
fs/configfs/inode.c | 6 -
fs/dcache.c | 135 ++++--------------------------
fs/exportfs/expfs.c | 4
fs/namei.c | 9 --
fs/ncpfs/dir.c | 3
fs/ncpfs/ncplib_kernel.h | 4
fs/nfs/dir.c | 3
fs/nfs/getroot.c | 2
fs/nfs/namespace.c | 3
fs/notify/fsnotify.c | 2
fs/notify/inotify/inotify.c | 4
fs/ocfs2/dcache.c | 2
fs/seq_file.c | 2
fs/smbfs/cache.c | 4
include/linux/dcache.h | 17 +--
include/linux/fs.h | 4
include/linux/fsnotify_backend.h | 5 -
kernel/cgroup.c | 6 -
security/selinux/selinuxfs.c | 4
security/tomoyo/realpath.c | 2
35 files changed, 67 insertions(+), 239 deletions(-)

Index: linux-2.6/fs/dcache.c
===================================================================
--- linux-2.6.orig/fs/dcache.c
+++ linux-2.6/fs/dcache.c
@@ -54,11 +54,10 @@
* - d_alias, d_inode
*
* Ordering:
- * dcache_lock
- * dcache_inode_lock
- * dentry->d_lock
- * dcache_lru_lock
- * dcache_hash_lock
+ * dcache_inode_lock
+ * dentry->d_lock
+ * dcache_lru_lock
+ * dcache_hash_lock
*
* If there is an ancestor relationship:
* dentry->d_parent->...->d_parent->d_lock
@@ -77,13 +76,11 @@ EXPORT_SYMBOL_GPL(sysctl_vfs_cache_press
__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_inode_lock);
__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_hash_lock);
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lru_lock);
-__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lock);
__cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock);

EXPORT_SYMBOL(rename_lock);
EXPORT_SYMBOL(dcache_inode_lock);
EXPORT_SYMBOL(dcache_hash_lock);
-EXPORT_SYMBOL(dcache_lock);

static struct kmem_cache *dentry_cache __read_mostly;

@@ -125,7 +122,7 @@ static void d_callback(struct rcu_head *
}

/*
- * no dcache_lock, please.
+ * no locks, please.
*/
static void d_free(struct dentry *dentry)
{
@@ -147,7 +144,6 @@ static void d_free(struct dentry *dentry
static void dentry_iput(struct dentry * dentry)
__releases(dentry->d_lock)
__releases(dcache_inode_lock)
- __releases(dcache_lock)
{
struct inode *inode = dentry->d_inode;
if (inode) {
@@ -155,7 +151,6 @@ static void dentry_iput(struct dentry *
list_del_init(&dentry->d_alias);
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
if (!inode->i_nlink)
fsnotify_inoderemove(inode);
if (dentry->d_op && dentry->d_op->d_iput)
@@ -165,7 +160,6 @@ static void dentry_iput(struct dentry *
} else {
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
}
}

@@ -231,13 +225,12 @@ static void dentry_lru_del_init(struct d
*
* If this is the root of the dentry tree, return NULL.
*
- * dcache_lock and d_lock and d_parent->d_lock must be held by caller, and
+ * d_lock and d_parent->d_lock must be held by caller, and
* are dropped by d_kill.
*/
static struct dentry *d_kill(struct dentry *dentry)
__releases(dentry->d_lock)
__releases(dcache_inode_lock)
- __releases(dcache_lock)
{
struct dentry *parent;

@@ -294,21 +287,10 @@ repeat:
might_sleep();
spin_lock(&dentry->d_lock);
if (dentry->d_count == 1) {
- if (!spin_trylock(&dcache_lock)) {
- /*
- * Something of a livelock possibility we could avoid
- * by taking dcache_lock and trying again, but we
- * want to reduce dcache_lock anyway so this will
- * get improved.
- */
-drop1:
- spin_unlock(&dentry->d_lock);
- goto repeat;
- }
if (!spin_trylock(&dcache_inode_lock)) {
drop2:
- spin_unlock(&dcache_lock);
- goto drop1;
+ spin_unlock(&dentry->d_lock);
+ goto repeat;
}
parent = dentry->d_parent;
if (parent && parent != dentry) {
@@ -323,7 +305,6 @@ drop2:
spin_unlock(&dentry->d_lock);
if (parent && parent != dentry)
spin_unlock(&parent->d_lock);
- spin_unlock(&dcache_lock);
return;
}

@@ -345,7 +326,6 @@ drop2:
if (parent && parent != dentry)
spin_unlock(&parent->d_lock);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
return;

unhash_it:
@@ -376,11 +356,9 @@ int d_invalidate(struct dentry * dentry)
/*
* If it's already been dropped, return OK.
*/
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
if (d_unhashed(dentry)) {
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
return 0;
}
/*
@@ -389,9 +367,7 @@ int d_invalidate(struct dentry * dentry)
*/
if (!list_empty(&dentry->d_subdirs)) {
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
shrink_dcache_parent(dentry);
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
}

@@ -408,19 +384,17 @@ int d_invalidate(struct dentry * dentry)
if (dentry->d_count > 1) {
if (dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode)) {
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
return -EBUSY;
}
}

__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
return 0;
}
EXPORT_SYMBOL(d_invalidate);

-/* This must be called with dcache_lock and d_lock held */
+/* This must be called with d_lock held */
static inline struct dentry * __dget_locked_dlock(struct dentry *dentry)
{
dentry->d_count++;
@@ -428,7 +402,7 @@ static inline struct dentry * __dget_loc
return dentry;
}

-/* This should be called _only_ with dcache_lock held */
+/* This must be called with d_lock held */
static inline struct dentry * __dget_locked(struct dentry *dentry)
{
spin_lock(&dentry->d_lock);
@@ -526,11 +500,9 @@ struct dentry * d_find_alias(struct inod
struct dentry *de = NULL;

if (!list_empty(&inode->i_dentry)) {
- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
de = __d_find_alias(inode, 0);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
}
return de;
}
@@ -544,7 +516,6 @@ void d_prune_aliases(struct inode *inode
{
struct dentry *dentry;
restart:
- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
spin_lock(&dentry->d_lock);
@@ -553,14 +524,12 @@ restart:
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
dput(dentry);
goto restart;
}
spin_unlock(&dentry->d_lock);
}
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
}
EXPORT_SYMBOL(d_prune_aliases);

@@ -574,20 +543,16 @@ EXPORT_SYMBOL(d_prune_aliases);
*/
static void prune_one_dentry(struct dentry * dentry)
__releases(dentry->d_lock)
- __releases(dcache_lock)
- __acquires(dcache_lock)
{
__d_drop(dentry);
dentry = d_kill(dentry);

/*
- * Prune ancestors. Locking is simpler than in dput(),
- * because dcache_lock needs to be taken anyway.
+ * Prune ancestors.
*/
while (dentry) {
struct dentry *parent = NULL;

- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
again:
spin_lock(&dentry->d_lock);
@@ -604,7 +569,6 @@ again:
spin_unlock(&parent->d_lock);
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
return;
}

@@ -673,7 +637,6 @@ restart:
}
spin_unlock(&dcache_lru_lock);

- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
again:
spin_lock(&dcache_lru_lock); /* lru_lock also protects tmp list */
@@ -703,14 +666,13 @@ again1:
}
__dentry_lru_del_init(dentry);
spin_unlock(&dcache_lru_lock);
+
prune_one_dentry(dentry);
- /* dcache_lock and dentry->d_lock dropped */
- spin_lock(&dcache_lock);
+ /* dentry->d_lock dropped */
spin_lock(&dcache_inode_lock);
spin_lock(&dcache_lru_lock);
}
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);

if (count == NULL && !list_empty(&sb->s_dentry_lru))
goto restart;
@@ -740,7 +702,6 @@ static void prune_dcache(int count)

if (unused == 0 || count == 0)
return;
- spin_lock(&dcache_lock);
if (count >= unused)
prune_ratio = 1;
else
@@ -777,11 +738,9 @@ static void prune_dcache(int count)
if (down_read_trylock(&sb->s_umount)) {
if ((sb->s_root != NULL) &&
(!list_empty(&sb->s_dentry_lru))) {
- spin_unlock(&dcache_lock);
__shrink_dcache_sb(sb, &w_count,
DCACHE_REFERENCED);
pruned -= w_count;
- spin_lock(&dcache_lock);
}
up_read(&sb->s_umount);
}
@@ -795,7 +754,6 @@ static void prune_dcache(int count)
break;
}
spin_unlock(&sb_lock);
- spin_unlock(&dcache_lock);
}

/**
@@ -825,12 +783,10 @@ static void shrink_dcache_for_umount_sub
BUG_ON(!IS_ROOT(dentry));

/* detach this root from the system */
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
dentry_lru_del_init(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);

for (;;) {
/* descend to the first leaf in the current subtree */
@@ -839,7 +795,6 @@ static void shrink_dcache_for_umount_sub

/* this is a branch with children - detach all of them
* from the system in one go */
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
list_for_each_entry(loop, &dentry->d_subdirs,
d_u.d_child) {
@@ -849,7 +804,6 @@ static void shrink_dcache_for_umount_sub
spin_unlock(&loop->d_lock);
}
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);

/* move to the first child */
dentry = list_entry(dentry->d_subdirs.next,
@@ -920,8 +874,7 @@ out:

/*
* destroy the dentries attached to a superblock on unmounting
- * - we don't need to use dentry->d_lock, and only need dcache_lock when
- * removing the dentry from the system lists and hashes because:
+ * - we don't need to use dentry->d_lock because:
* - the superblock is detached from all mountings and open files, so the
* dentry trees will not be rearranged by the VFS
* - s_umount is write-locked, so the memory pressure shrinker will ignore
@@ -972,7 +925,6 @@ rename_retry:
this_parent = parent;
seq = read_seqbegin(&rename_lock);

- spin_lock(&dcache_lock);
if (d_mountpoint(parent))
goto positive;
spin_lock(&this_parent->d_lock);
@@ -1019,7 +971,6 @@ resume:
// d_unlinked(this_parent) || XXX
read_seqretry(&rename_lock, seq)) {
spin_unlock(&this_parent->d_lock);
- spin_unlock(&dcache_lock);
rcu_read_unlock();
goto rename_retry;
}
@@ -1028,12 +979,10 @@ resume:
goto resume;
}
spin_unlock(&this_parent->d_lock);
- spin_unlock(&dcache_lock);
if (read_seqretry(&rename_lock, seq))
goto rename_retry;
return 0; /* No mount points found in tree */
positive:
- spin_unlock(&dcache_lock);
if (read_seqretry(&rename_lock, seq))
goto rename_retry;
return 1;
@@ -1066,7 +1015,6 @@ rename_retry:
this_parent = parent;
seq = read_seqbegin(&rename_lock);

- spin_lock(&dcache_lock);
spin_lock(&this_parent->d_lock);
repeat:
next = this_parent->d_subdirs.next;
@@ -1129,7 +1077,6 @@ resume:
// d_unlinked(this_parent) || XXX
read_seqretry(&rename_lock, seq)) {
spin_unlock(&this_parent->d_lock);
- spin_unlock(&dcache_lock);
rcu_read_unlock();
goto rename_retry;
}
@@ -1139,7 +1086,6 @@ resume:
}
out:
spin_unlock(&this_parent->d_lock);
- spin_unlock(&dcache_lock);
if (read_seqretry(&rename_lock, seq))
goto rename_retry;
return found;
@@ -1240,7 +1186,6 @@ struct dentry *d_alloc(struct dentry * p
INIT_LIST_HEAD(&dentry->d_u.d_child);

if (parent) {
- spin_lock(&dcache_lock);
spin_lock(&parent->d_lock);
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
dentry->d_parent = dget_dlock(parent);
@@ -1248,7 +1193,6 @@ struct dentry *d_alloc(struct dentry * p
list_add(&dentry->d_u.d_child, &parent->d_subdirs);
spin_unlock(&dentry->d_lock);
spin_unlock(&parent->d_lock);
- spin_unlock(&dcache_lock);
}

atomic_inc(&dentry_stat.nr_dentry);
@@ -1268,7 +1212,6 @@ struct dentry *d_alloc_name(struct dentr
}
EXPORT_SYMBOL(d_alloc_name);

-/* the caller must hold dcache_lock */
static void __d_instantiate(struct dentry *dentry, struct inode *inode)
{
spin_lock(&dentry->d_lock);
@@ -1297,11 +1240,9 @@ static void __d_instantiate(struct dentr
void d_instantiate(struct dentry *entry, struct inode * inode)
{
BUG_ON(!list_empty(&entry->d_alias));
- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
__d_instantiate(entry, inode);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
security_d_instantiate(entry, inode);
}
EXPORT_SYMBOL(d_instantiate);
@@ -1360,11 +1301,9 @@ struct dentry *d_instantiate_unique(stru

BUG_ON(!list_empty(&entry->d_alias));

- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
result = __d_instantiate_unique(entry, inode);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);

if (!result) {
security_d_instantiate(entry, inode);
@@ -1453,12 +1392,10 @@ struct dentry *d_obtain_alias(struct ino
}
tmp->d_parent = tmp; /* make sure dput doesn't croak */

- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
res = __d_find_alias(inode, 0);
if (res) {
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
dput(tmp);
goto out_iput;
}
@@ -1474,7 +1411,6 @@ struct dentry *d_obtain_alias(struct ino
spin_unlock(&tmp->d_lock);
spin_unlock(&dcache_inode_lock);

- spin_unlock(&dcache_lock);
return tmp;

out_iput:
@@ -1504,21 +1440,18 @@ struct dentry *d_splice_alias(struct ino
struct dentry *new = NULL;

if (inode && S_ISDIR(inode->i_mode)) {
- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
new = __d_find_alias(inode, 1);
if (new) {
BUG_ON(!(new->d_flags & DCACHE_DISCONNECTED));
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
security_d_instantiate(new, inode);
d_move(new, dentry);
iput(inode);
} else {
- /* already taking dcache_lock, so d_add() by hand */
+ /* already got dcache_inode_lock, so d_add() by hand */
__d_instantiate(dentry, inode);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
security_d_instantiate(dentry, inode);
d_rehash(dentry);
}
@@ -1591,12 +1524,10 @@ struct dentry *d_add_ci(struct dentry *d
* Negative dentry: instantiate it unless the inode is a directory and
* already has a dentry.
*/
- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
if (!S_ISDIR(inode->i_mode) || list_empty(&inode->i_dentry)) {
__d_instantiate(found, inode);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
security_d_instantiate(found, inode);
return found;
}
@@ -1608,7 +1539,6 @@ struct dentry *d_add_ci(struct dentry *d
new = list_entry(inode->i_dentry.next, struct dentry, d_alias);
dget_locked(new);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
security_d_instantiate(found, inode);
d_move(new, found);
iput(inode);
@@ -1631,7 +1561,7 @@ EXPORT_SYMBOL(d_add_ci);
* is returned. The caller must use dput to free the entry when it has
* finished using it. %NULL is returned on failure.
*
- * __d_lookup is dcache_lock free. The hash list is protected using RCU.
+ * __d_lookup is global lock free. The hash list is protected using RCU.
* Memory barriers are used while updating and doing lockless traversal.
* To avoid races with d_move while rename is happening, d_lock is used.
*
@@ -1643,7 +1573,7 @@ EXPORT_SYMBOL(d_add_ci);
*
* The dentry unused LRU is not updated even if lookup finds the required dentry
* in there. It is updated in places such as prune_dcache, shrink_dcache_sb,
- * select_parent and __dget_locked. This laziness saves lookup from dcache_lock
+ * select_parent and __dget_locked. This laziness saves lookup from LRU lock
* acquisition.
*
* d_lookup() is protected against the concurrent renames in some unrelated
@@ -1774,25 +1704,22 @@ int d_validate(struct dentry *dentry, st
if (dentry->d_parent != dparent)
goto out;

- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
spin_lock(&dcache_hash_lock);
base = d_hash(dparent, dentry->d_name.hash);
hlist_for_each(lhp,base) {
/* hlist_for_each_entry_rcu() not required for d_hash list
- * as it is parsed under dcache_lock
+ * as it is parsed under dcache_hash_lock
*/
if (dentry == hlist_entry(lhp, struct dentry, d_hash)) {
spin_unlock(&dcache_hash_lock);
__dget_locked_dlock(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
return 1;
}
}
spin_unlock(&dcache_hash_lock);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
out:
return 0;
}
@@ -1825,7 +1752,6 @@ void d_delete(struct dentry * dentry)
/*
* Are we the only user?
*/
- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
spin_lock(&dentry->d_lock);
isdir = S_ISDIR(dentry->d_inode->i_mode);
@@ -1841,7 +1767,6 @@ void d_delete(struct dentry * dentry)

spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);

fsnotify_nameremove(dentry, isdir);
}
@@ -1868,13 +1793,11 @@ static void _d_rehash(struct dentry * en

void d_rehash(struct dentry * entry)
{
- spin_lock(&dcache_lock);
spin_lock(&entry->d_lock);
spin_lock(&dcache_hash_lock);
_d_rehash(entry);
spin_unlock(&dcache_hash_lock);
spin_unlock(&entry->d_lock);
- spin_unlock(&dcache_lock);
}
EXPORT_SYMBOL(d_rehash);

@@ -2032,9 +1955,7 @@ static void d_move_locked(struct dentry

void d_move(struct dentry * dentry, struct dentry * target)
{
- spin_lock(&dcache_lock);
d_move_locked(dentry, target);
- spin_unlock(&dcache_lock);
}
EXPORT_SYMBOL(d_move);

@@ -2061,13 +1982,12 @@ struct dentry *d_ancestor(struct dentry
* This helper attempts to cope with remotely renamed directories
*
* It assumes that the caller is already holding
- * dentry->d_parent->d_inode->i_mutex and the dcache_lock
+ * dentry->d_parent->d_inode->i_mutex
*
* Note: If ever the locking in lock_rename() changes, then please
* remember to update this too...
*/
static struct dentry *__d_unalias(struct dentry *dentry, struct dentry *alias)
- __releases(dcache_lock)
{
struct mutex *m1 = NULL, *m2 = NULL;
struct dentry *ret;
@@ -2094,7 +2014,6 @@ out_unalias:
ret = alias;
out_err:
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
if (m2)
mutex_unlock(m2);
if (m1)
@@ -2158,7 +2077,6 @@ struct dentry *d_materialise_unique(stru

BUG_ON(!d_unhashed(dentry));

- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);

if (!inode) {
@@ -2204,7 +2122,6 @@ found:
spin_unlock(&dcache_hash_lock);
spin_unlock(&actual->d_lock);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
out_nolock:
if (actual == dentry) {
security_d_instantiate(dentry, inode);
@@ -2216,7 +2133,6 @@ out_nolock:

shouldnt_be_hashed:
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
BUG();
}
EXPORT_SYMBOL_GPL(d_materialise_unique);
@@ -2249,8 +2165,7 @@ static int prepend_name(char **buffer, i
* Returns a pointer into the buffer or an error code if the
* path was too long.
*
- * "buflen" should be positive. Caller holds the dcache_lock and
- * path->dentry->d_lock.
+ * "buflen" should be positive. Caller holds the path->dentry->d_lock.
*
* If path is not reachable from the supplied root, then the value of
* root is changed (without modifying refcounts).
@@ -2371,12 +2286,10 @@ char *d_path(const struct path *path, ch
path_get(&root);
spin_unlock(&current->fs->lock);

- spin_lock(&dcache_lock);
br_read_lock(vfsmount_lock);
tmp = root;
res = __d_path(path, &tmp, buf, buflen);
br_read_unlock(vfsmount_lock);
- spin_unlock(&dcache_lock);

path_put(&root);
return res;
@@ -2418,7 +2331,6 @@ rename_retry:
prepend(&end, &buflen, "\0", 1);

seq = read_seqbegin(&rename_lock);
- spin_lock(&dcache_lock);
br_read_lock(vfsmount_lock);
rcu_read_lock(); /* protect parent */
spin_lock(&dentry->d_lock);
@@ -2451,7 +2363,6 @@ out:
spin_unlock(&dentry->d_lock);
rcu_read_unlock();
br_read_unlock(vfsmount_lock);
- spin_unlock(&dcache_lock);
if (read_seqretry(&rename_lock, seq))
goto rename_retry;
return retval;
@@ -2495,7 +2406,6 @@ SYSCALL_DEFINE2(getcwd, char __user *, b
spin_unlock(&current->fs->lock);

error = -ENOENT;
- spin_lock(&dcache_lock);
br_read_lock(vfsmount_lock);
spin_lock(&pwd.dentry->d_lock);
if (!d_unlinked(pwd.dentry)) {
@@ -2507,7 +2417,6 @@ SYSCALL_DEFINE2(getcwd, char __user *, b
/* XXX: race here, have to close (eg. return unlinked from __d_path) */
cwd = __d_path(&pwd, &tmp, page, PAGE_SIZE);
br_read_unlock(vfsmount_lock);
- spin_unlock(&dcache_lock);

error = PTR_ERR(cwd);
if (IS_ERR(cwd))
@@ -2523,7 +2432,6 @@ SYSCALL_DEFINE2(getcwd, char __user *, b
} else {
spin_unlock(&pwd.dentry->d_lock);
br_read_unlock(vfsmount_lock);
- spin_unlock(&dcache_lock);
}

out:
@@ -2609,7 +2517,6 @@ void d_genocide(struct dentry *root)
rename_retry:
this_parent = root;
seq = read_seqbegin(&rename_lock);
- spin_lock(&dcache_lock);
spin_lock(&this_parent->d_lock);
repeat:
next = this_parent->d_subdirs.next;
@@ -2657,7 +2564,6 @@ resume:
// d_unlinked(this_parent) || XXX
read_seqretry(&rename_lock, seq)) {
spin_unlock(&this_parent->d_lock);
- spin_unlock(&dcache_lock);
rcu_read_unlock();
goto rename_retry;
}
@@ -2666,7 +2572,6 @@ resume:
goto resume;
}
spin_unlock(&this_parent->d_lock);
- spin_unlock(&dcache_lock);
if (read_seqretry(&rename_lock, seq))
goto rename_retry;
}
Index: linux-2.6/fs/namei.c
===================================================================
--- linux-2.6.orig/fs/namei.c
+++ linux-2.6/fs/namei.c
@@ -618,8 +618,8 @@ int follow_up(struct path *path)
return 1;
}

-/* no need for dcache_lock, as serialization is taken care in
- * namespace.c
+/*
+ * serialization is taken care of in namespace.c
*/
static int __follow_mount(struct path *path)
{
@@ -651,9 +651,6 @@ static void follow_mount(struct path *pa
}
}

-/* no need for dcache_lock, as serialization is taken care in
- * namespace.c
- */
int follow_down(struct path *path)
{
struct vfsmount *mounted;
@@ -2152,12 +2149,10 @@ void dentry_unhash(struct dentry *dentry
{
dget(dentry);
shrink_dcache_parent(dentry);
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
if (dentry->d_count == 2)
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
}

int vfs_rmdir(struct inode *dir, struct dentry *dentry)
Index: linux-2.6/fs/seq_file.c
===================================================================
--- linux-2.6.orig/fs/seq_file.c
+++ linux-2.6/fs/seq_file.c
@@ -465,11 +465,9 @@ int seq_path_root(struct seq_file *m, st
if (size) {
char *p;

- spin_lock(&dcache_lock);
br_read_lock(vfsmount_lock);
p = __d_path(path, root, buf, size);
br_read_unlock(vfsmount_lock);
- spin_unlock(&dcache_lock);

res = PTR_ERR(p);
if (!IS_ERR(p)) {
Index: linux-2.6/include/linux/dcache.h
===================================================================
--- linux-2.6.orig/include/linux/dcache.h
+++ linux-2.6/include/linux/dcache.h
@@ -150,13 +150,13 @@ struct dentry_operations {

/*
locking rules:
- big lock dcache_lock d_lock may block
-d_revalidate: no no no yes
-d_hash no no no yes
-d_compare: no yes yes no
-d_delete: no yes no no
-d_release: no no no yes
-d_iput: no no no yes
+ big lock d_lock may block
+d_revalidate: no no yes
+d_hash no no yes
+d_compare: no yes no
+d_delete: no no no
+d_release: no no yes
+d_iput: no no yes
*/

/* d_flags entries */
@@ -191,7 +191,6 @@ d_iput: no no no yes

extern spinlock_t dcache_inode_lock;
extern spinlock_t dcache_hash_lock;
-extern spinlock_t dcache_lock;
extern seqlock_t rename_lock;

/**
@@ -222,11 +221,9 @@ static inline void __d_drop(struct dentr

static inline void d_drop(struct dentry *dentry)
{
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
}

static inline int dname_external(struct dentry *dentry)
Index: linux-2.6/fs/notify/inotify/inotify.c
===================================================================
--- linux-2.6.orig/fs/notify/inotify/inotify.c
+++ linux-2.6/fs/notify/inotify/inotify.c
@@ -181,7 +181,6 @@ static void set_dentry_child_flags(struc
{
struct dentry *alias;

- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
list_for_each_entry(alias, &inode->i_dentry, d_alias) {
struct dentry *child;
@@ -201,7 +200,6 @@ static void set_dentry_child_flags(struc
spin_unlock(&alias->d_lock);
}
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
}

/*
@@ -269,6 +267,7 @@ void inotify_d_instantiate(struct dentry
if (!inode)
return;

+ /* XXX: need parent lock in place of dcache_lock? */
spin_lock(&entry->d_lock);
parent = entry->d_parent;
if (parent->d_inode && inotify_inode_watched(parent->d_inode))
@@ -283,6 +282,7 @@ void inotify_d_move(struct dentry *entry
{
struct dentry *parent;

+ /* XXX: need parent lock in place of dcache_lock? */
parent = entry->d_parent;
if (inotify_inode_watched(parent->d_inode))
entry->d_flags |= DCACHE_INOTIFY_PARENT_WATCHED;
Index: linux-2.6/fs/exportfs/expfs.c
===================================================================
--- linux-2.6.orig/fs/exportfs/expfs.c
+++ linux-2.6/fs/exportfs/expfs.c
@@ -47,24 +47,20 @@ find_acceptable_alias(struct dentry *res
if (acceptable(context, result))
return result;

- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
list_for_each_entry(dentry, &result->d_inode->i_dentry, d_alias) {
dget_locked(dentry);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
if (toput)
dput(toput);
if (dentry != result && acceptable(context, dentry)) {
dput(result);
return dentry;
}
- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
toput = dentry;
}
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);

if (toput)
dput(toput);
Index: linux-2.6/Documentation/filesystems/Locking
===================================================================
--- linux-2.6.orig/Documentation/filesystems/Locking
+++ linux-2.6/Documentation/filesystems/Locking
@@ -17,7 +17,7 @@ prototypes:
void (*d_iput)(struct dentry *, struct inode *);
char *(*d_dname)((struct dentry *dentry, char *buffer, int buflen);

-locking rules:
+locking rules: XXX: update these!!
none have BKL
dcache_lock rename_lock ->d_lock may block
d_revalidate: no no no yes
Index: linux-2.6/arch/powerpc/platforms/cell/spufs/inode.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/inode.c
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/inode.c
@@ -158,21 +158,18 @@ static void spufs_prune_dir(struct dentr

mutex_lock(&dir->d_inode->i_mutex);
list_for_each_entry_safe(dentry, tmp, &dir->d_subdirs, d_u.d_child) {
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
if (!(d_unhashed(dentry)) && dentry->d_inode) {
dget_locked_dlock(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
simple_unlink(dir->d_inode, dentry);
- /* XXX: what is dcache_lock protecting here? Other
+ /* XXX: what was dcache_lock protecting here? Other
* filesystems (IB, configfs) release dcache_lock
* before unlink */
- spin_unlock(&dcache_lock);
dput(dentry);
} else {
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
}
}
shrink_dcache_parent(dir);
Index: linux-2.6/drivers/infiniband/hw/ipath/ipath_fs.c
===================================================================
--- linux-2.6.orig/drivers/infiniband/hw/ipath/ipath_fs.c
+++ linux-2.6/drivers/infiniband/hw/ipath/ipath_fs.c
@@ -273,18 +273,14 @@ static int remove_file(struct dentry *pa
goto bail;
}

- spin_lock(&dcache_lock);
spin_lock(&tmp->d_lock);
if (!(d_unhashed(tmp) && tmp->d_inode)) {
dget_locked_dlock(tmp);
__d_drop(tmp);
spin_unlock(&tmp->d_lock);
- spin_unlock(&dcache_lock);
simple_unlink(parent->d_inode, tmp);
- } else {
+ } else
spin_unlock(&tmp->d_lock);
- spin_unlock(&dcache_lock);
- }

ret = 0;
bail:
Index: linux-2.6/drivers/usb/core/inode.c
===================================================================
--- linux-2.6.orig/drivers/usb/core/inode.c
+++ linux-2.6/drivers/usb/core/inode.c
@@ -347,7 +347,6 @@ static int usbfs_empty (struct dentry *d
{
struct list_head *list;

- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
list_for_each(list, &dentry->d_subdirs) {
struct dentry *de = list_entry(list, struct dentry, d_u.d_child);
@@ -356,13 +355,11 @@ static int usbfs_empty (struct dentry *d
if (usbfs_positive(de)) {
spin_unlock(&de->d_lock);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
return 0;
}
spin_unlock(&de->d_lock);
}
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
return 1;
}

Index: linux-2.6/fs/affs/amigaffs.c
===================================================================
--- linux-2.6.orig/fs/affs/amigaffs.c
+++ linux-2.6/fs/affs/amigaffs.c
@@ -128,7 +128,6 @@ affs_fix_dcache(struct dentry *dentry, u
void *data = dentry->d_fsdata;
struct list_head *head, *next;

- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
head = &inode->i_dentry;
next = head->next;
@@ -141,7 +140,6 @@ affs_fix_dcache(struct dentry *dentry, u
next = next->next;
}
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
}

Index: linux-2.6/fs/coda/cache.c
===================================================================
--- linux-2.6.orig/fs/coda/cache.c
+++ linux-2.6/fs/coda/cache.c
@@ -86,7 +86,6 @@ static void coda_flag_children(struct de
struct list_head *child;
struct dentry *de;

- spin_lock(&dcache_lock);
spin_lock(&parent->d_lock);
list_for_each(child, &parent->d_subdirs)
{
@@ -97,7 +96,6 @@ static void coda_flag_children(struct de
coda_flag_inode(de->d_inode, flag);
}
spin_unlock(&parent->d_lock);
- spin_unlock(&dcache_lock);
return;
}

Index: linux-2.6/fs/configfs/configfs_internal.h
===================================================================
--- linux-2.6.orig/fs/configfs/configfs_internal.h
+++ linux-2.6/fs/configfs/configfs_internal.h
@@ -120,7 +120,6 @@ static inline struct config_item *config
{
struct config_item * item = NULL;

- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
if (!d_unhashed(dentry)) {
struct configfs_dirent * sd = dentry->d_fsdata;
@@ -131,7 +130,6 @@ static inline struct config_item *config
item = config_item_get(sd->s_element);
}
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);

return item;
}
Index: linux-2.6/fs/configfs/inode.c
===================================================================
--- linux-2.6.orig/fs/configfs/inode.c
+++ linux-2.6/fs/configfs/inode.c
@@ -249,18 +249,14 @@ void configfs_drop_dentry(struct configf
struct dentry * dentry = sd->s_dentry;

if (dentry) {
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
if (!(d_unhashed(dentry) && dentry->d_inode)) {
dget_locked_dlock(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
simple_unlink(parent->d_inode, dentry);
- } else {
+ } else
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
- }
}
}

Index: linux-2.6/fs/ncpfs/dir.c
===================================================================
--- linux-2.6.orig/fs/ncpfs/dir.c
+++ linux-2.6/fs/ncpfs/dir.c
@@ -364,7 +364,6 @@ ncp_dget_fpos(struct dentry *dentry, str
}

/* If a pointer is invalid, we search the dentry. */
- spin_lock(&dcache_lock);
spin_lock(&parent->d_lock);
next = parent->d_subdirs.next;
while (next != &parent->d_subdirs) {
@@ -375,13 +374,11 @@ ncp_dget_fpos(struct dentry *dentry, str
else
dent = NULL;
spin_unlock(&parent->d_lock);
- spin_unlock(&dcache_lock);
goto out;
}
next = next->next;
}
spin_unlock(&parent->d_lock);
- spin_unlock(&dcache_lock);
return NULL;

out:
Index: linux-2.6/fs/ncpfs/ncplib_kernel.h
===================================================================
--- linux-2.6.orig/fs/ncpfs/ncplib_kernel.h
+++ linux-2.6/fs/ncpfs/ncplib_kernel.h
@@ -192,7 +192,6 @@ ncp_renew_dentries(struct dentry *parent
struct list_head *next;
struct dentry *dentry;

- spin_lock(&dcache_lock);
spin_lock(&parent->d_lock);
next = parent->d_subdirs.next;
while (next != &parent->d_subdirs) {
@@ -206,7 +205,6 @@ ncp_renew_dentries(struct dentry *parent
next = next->next;
}
spin_unlock(&parent->d_lock);
- spin_unlock(&dcache_lock);
}

static inline void
@@ -216,7 +214,6 @@ ncp_invalidate_dircache_entries(struct d
struct list_head *next;
struct dentry *dentry;

- spin_lock(&dcache_lock);
spin_lock(&parent->d_lock);
next = parent->d_subdirs.next;
while (next != &parent->d_subdirs) {
@@ -226,7 +223,6 @@ ncp_invalidate_dircache_entries(struct d
next = next->next;
}
spin_unlock(&parent->d_lock);
- spin_unlock(&dcache_lock);
}

struct ncp_cache_head {
Index: linux-2.6/fs/nfs/dir.c
===================================================================
--- linux-2.6.orig/fs/nfs/dir.c
+++ linux-2.6/fs/nfs/dir.c
@@ -1464,11 +1464,9 @@ static int nfs_unlink(struct inode *dir,
dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id,
dir->i_ino, dentry->d_name.name);

- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
if (dentry->d_count > 1) {
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
/* Start asynchronous writeout of the inode */
write_inode_now(dentry->d_inode, 0);
error = nfs_sillyrename(dir, dentry);
@@ -1479,7 +1477,6 @@ static int nfs_unlink(struct inode *dir,
need_rehash = 1;
}
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
error = nfs_safe_remove(dentry);
if (!error || error == -ENOENT) {
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
Index: linux-2.6/fs/ocfs2/dcache.c
===================================================================
--- linux-2.6.orig/fs/ocfs2/dcache.c
+++ linux-2.6/fs/ocfs2/dcache.c
@@ -151,7 +151,6 @@ struct dentry *ocfs2_find_local_alias(st
struct list_head *p;
struct dentry *dentry = NULL;

- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
list_for_each(p, &inode->i_dentry) {
dentry = list_entry(p, struct dentry, d_alias);
@@ -171,7 +170,6 @@ struct dentry *ocfs2_find_local_alias(st
}

spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);

return dentry;
}
Index: linux-2.6/fs/smbfs/cache.c
===================================================================
--- linux-2.6.orig/fs/smbfs/cache.c
+++ linux-2.6/fs/smbfs/cache.c
@@ -62,7 +62,6 @@ smb_invalidate_dircache_entries(struct d
struct list_head *next;
struct dentry *dentry;

- spin_lock(&dcache_lock);
spin_lock(&parent->d_lock);
next = parent->d_subdirs.next;
while (next != &parent->d_subdirs) {
@@ -72,7 +71,6 @@ smb_invalidate_dircache_entries(struct d
next = next->next;
}
spin_unlock(&parent->d_lock);
- spin_unlock(&dcache_lock);
}

/*
@@ -98,7 +96,6 @@ smb_dget_fpos(struct dentry *dentry, str
}

/* If a pointer is invalid, we search the dentry. */
- spin_lock(&dcache_lock);
spin_lock(&parent->d_lock);
next = parent->d_subdirs.next;
while (next != &parent->d_subdirs) {
@@ -115,7 +112,6 @@ smb_dget_fpos(struct dentry *dentry, str
dent = NULL;
out_unlock:
spin_unlock(&parent->d_lock);
- spin_unlock(&dcache_lock);
return dent;
}

Index: linux-2.6/kernel/cgroup.c
===================================================================
--- linux-2.6.orig/kernel/cgroup.c
+++ linux-2.6/kernel/cgroup.c
@@ -869,7 +869,6 @@ static void cgroup_clear_directory(struc
struct list_head *node;

BUG_ON(!mutex_is_locked(&dentry->d_inode->i_mutex));
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
node = dentry->d_subdirs.next;
while (node != &dentry->d_subdirs) {
@@ -884,18 +883,15 @@ static void cgroup_clear_directory(struc
dget_locked_dlock(d);
spin_unlock(&d->d_lock);
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
d_delete(d);
simple_unlink(dentry->d_inode, d);
dput(d);
- spin_lock(&dcache_lock);
spin_lock(&dentry->d_lock);
} else
spin_unlock(&d->d_lock);
node = dentry->d_subdirs.next;
}
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
}

/*
@@ -907,14 +903,12 @@ static void cgroup_d_remove_dir(struct d

cgroup_clear_directory(dentry);

- spin_lock(&dcache_lock);
parent = dentry->d_parent;
spin_lock(&parent->d_lock);
spin_lock(&dentry->d_lock);
list_del_init(&dentry->d_u.d_child);
spin_unlock(&dentry->d_lock);
spin_unlock(&parent->d_lock);
- spin_unlock(&dcache_lock);
remove_dir(dentry);
}

Index: linux-2.6/security/selinux/selinuxfs.c
===================================================================
--- linux-2.6.orig/security/selinux/selinuxfs.c
+++ linux-2.6/security/selinux/selinuxfs.c
@@ -941,7 +941,6 @@ static void sel_remove_entries(struct de
{
struct list_head *node;

- spin_lock(&dcache_lock);
spin_lock(&de->d_lock);
node = de->d_subdirs.next;
while (node != &de->d_subdirs) {
@@ -954,11 +953,9 @@ static void sel_remove_entries(struct de
dget_locked_dlock(d);
spin_unlock(&de->d_lock);
spin_unlock(&d->d_lock);
- spin_unlock(&dcache_lock);
d_delete(d);
simple_unlink(de->d_inode, d);
dput(d);
- spin_lock(&dcache_lock);
spin_lock(&de->d_lock);
} else
spin_unlock(&d->d_lock);
@@ -966,7 +963,6 @@ static void sel_remove_entries(struct de
}

spin_unlock(&de->d_lock);
- spin_unlock(&dcache_lock);
}

#define BOOL_DIR_NAME "booleans"
Index: linux-2.6/security/tomoyo/realpath.c
===================================================================
--- linux-2.6.orig/security/tomoyo/realpath.c
+++ linux-2.6/security/tomoyo/realpath.c
@@ -92,12 +92,10 @@ int tomoyo_realpath_from_path2(struct pa
} else {
struct path ns_root = {.mnt = NULL, .dentry = NULL};

- spin_lock(&dcache_lock);
br_read_lock(vfsmount_lock);
/* go to whatever namespace root we are under */
sp = __d_path(path, &ns_root, newname, newname_len);
br_read_unlock(vfsmount_lock);
- spin_unlock(&dcache_lock);
/* Prepend "/proc" prefix if using internal proc vfs mount. */
if (!IS_ERR(sp) && (path->mnt->mnt_flags & MNT_INTERNAL) &&
(path->mnt->mnt_sb->s_magic == PROC_SUPER_MAGIC)) {
Index: linux-2.6/fs/nfs/getroot.c
===================================================================
--- linux-2.6.orig/fs/nfs/getroot.c
+++ linux-2.6/fs/nfs/getroot.c
@@ -64,13 +64,11 @@ static int nfs_superblock_set_dummy_root
* This again causes shrink_dcache_for_umount_subtree() to
* Oops, since the test for IS_ROOT() will fail.
*/
- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
spin_lock(&sb->s_root->d_lock);
list_del_init(&sb->s_root->d_alias);
spin_unlock(&sb->s_root->d_lock);
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
}
return 0;
}
Index: linux-2.6/drivers/staging/pohmelfs/path_entry.c
===================================================================
--- linux-2.6.orig/drivers/staging/pohmelfs/path_entry.c
+++ linux-2.6/drivers/staging/pohmelfs/path_entry.c
@@ -101,7 +101,6 @@ rename_retry:
d = first;
seq = read_seqbegin(&rename_lock);
rcu_read_lock();
- spin_lock(&dcache_lock);

if (!IS_ROOT(d) && d_unhashed(d))
len += UNHASHED_OBSCURE_STRING_SIZE; /* Obscure " (deleted)" string */
@@ -110,7 +109,6 @@ rename_retry:
len += d->d_name.len + 1; /* Plus slash */
d = d->d_parent;
}
- spin_unlock(&dcache_lock);
rcu_read_unlock();
if (read_seqretry(&rename_lock, seq))
goto rename_retry;
Index: linux-2.6/fs/nfs/namespace.c
===================================================================
--- linux-2.6.orig/fs/nfs/namespace.c
+++ linux-2.6/fs/nfs/namespace.c
@@ -60,7 +60,6 @@ rename_retry:

seq = read_seqbegin(&rename_lock);
rcu_read_lock();
- spin_lock(&dcache_lock);
while (!IS_ROOT(dentry) && dentry != droot) {
namelen = dentry->d_name.len;
buflen -= namelen + 1;
@@ -71,7 +70,6 @@ rename_retry:
*--end = '/';
dentry = dentry->d_parent;
}
- spin_unlock(&dcache_lock);
rcu_read_unlock();
if (read_seqretry(&rename_lock, seq))
goto rename_retry;
@@ -91,7 +89,6 @@ rename_retry:
memcpy(end, base, namelen);
return end;
Elong_unlock:
- spin_unlock(&dcache_lock);
rcu_read_unlock();
if (read_seqretry(&rename_lock, seq))
goto rename_retry;
Index: linux-2.6/include/linux/fsnotify_backend.h
===================================================================
--- linux-2.6.orig/include/linux/fsnotify_backend.h
+++ linux-2.6/include/linux/fsnotify_backend.h
@@ -276,10 +276,10 @@ static inline void __fsnotify_update_dca
{
struct dentry *parent;

- assert_spin_locked(&dcache_lock);
assert_spin_locked(&dentry->d_lock);

parent = dentry->d_parent;
+ /* XXX: after dcache_lock removal, there is a race with parent->d_inode and fsnotify_inode_watches_children. must fix */
if (parent->d_inode && fsnotify_inode_watches_children(parent->d_inode))
dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED;
else
@@ -288,15 +288,12 @@ static inline void __fsnotify_update_dca

/*
* fsnotify_d_instantiate - instantiate a dentry for inode
- * Called with dcache_lock held.
*/
static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode)
{
if (!inode)
return;

- assert_spin_locked(&dcache_lock);
-
spin_lock(&dentry->d_lock);
__fsnotify_update_dcache_flags(dentry);
spin_unlock(&dentry->d_lock);
Index: linux-2.6/fs/notify/fsnotify.c
===================================================================
--- linux-2.6.orig/fs/notify/fsnotify.c
+++ linux-2.6/fs/notify/fsnotify.c
@@ -53,7 +53,6 @@ void __fsnotify_update_child_dentry_flag
/* determine if the children should tell inode about their events */
watched = fsnotify_inode_watches_children(inode);

- spin_lock(&dcache_lock);
spin_lock(&dcache_inode_lock);
/* run all of the dentries associated with this inode. Since this is a
* directory, there damn well better only be one item on this list */
@@ -78,7 +77,6 @@ void __fsnotify_update_child_dentry_flag
spin_unlock(&alias->d_lock);
}
spin_unlock(&dcache_inode_lock);
- spin_unlock(&dcache_lock);
}

/* Notify this dentry's parent about a child's events. */
Index: linux-2.6/include/linux/fs.h
===================================================================
--- linux-2.6.orig/include/linux/fs.h
+++ linux-2.6/include/linux/fs.h
@@ -2425,6 +2425,10 @@ static inline ino_t parent_ino(struct de
{
ino_t res;

+ /*
+ * Don't strictly need d_lock here? If the parent ino could change
+ * then surely we'd have a deeper race in the caller?
+ */
spin_lock(&dentry->d_lock);
res = dentry->d_parent->d_inode->i_ino;
spin_unlock(&dentry->d_lock);
Index: linux-2.6/fs/autofs4/autofs_i.h
===================================================================
--- linux-2.6.orig/fs/autofs4/autofs_i.h
+++ linux-2.6/fs/autofs4/autofs_i.h
@@ -16,6 +16,7 @@
#include <linux/auto_fs4.h>
#include <linux/auto_dev-ioctl.h>
#include <linux/mutex.h>
+#include <linux/spinlock.h>
#include <linux/list.h>

/* This is the range of ioctl() numbers we claim as ours */
@@ -60,6 +61,8 @@ do { \
current->pid, __func__, ##args); \
} while (0)

+extern spinlock_t autofs4_lock;
+
/* Unified info structure. This is pointed to by both the dentry and
inode structures. Each file in the filesystem has an instance of this
structure. It holds a reference to the dentry, so dentries are never
Index: linux-2.6/fs/autofs4/expire.c
===================================================================
--- linux-2.6.orig/fs/autofs4/expire.c
+++ linux-2.6/fs/autofs4/expire.c
@@ -94,9 +94,9 @@ done:
* Calculate next entry in top down tree traversal.
* From next_mnt in namespace.c - elegant.
*
- * How is this supposed to work if we drop dcache_lock between calls anyway?
+ * How is this supposed to work if we drop autofs4_lock between calls anyway?
* How does it cope with renames?
- * And also callers dput the returned dentry before taking dcache_lock again
+ * And also callers dput the returned dentry before taking autofs4_lock again
* so what prevents it from being freed??
*/
static struct dentry *get_next_positive_dentry(struct dentry *p,
@@ -105,7 +105,7 @@ static struct dentry *get_next_positive_
struct list_head *next;
struct dentry *ret;

- spin_lock(&dcache_lock);
+ spin_lock(&autofs4_lock);
again:
spin_lock(&p->d_lock);
next = p->d_subdirs.next;
@@ -115,7 +115,7 @@ again:

if (p == root) {
spin_unlock(&p->d_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);
return NULL;
}

@@ -143,7 +143,7 @@ again:
dget_dlock(ret);
spin_unlock(&ret->d_lock);
spin_unlock(&p->d_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);

return ret;
}
@@ -313,7 +313,7 @@ struct dentry *autofs4_expire_direct(str
* A tree is eligible if :-
* - it is unused by any user process
* - it has been unused for exp_timeout time
- * This seems to be racy dropping dcache_lock and asking for next->next after
+ * This seems to be racy dropping autofs4_lock and asking for next->next after
* the lock has been dropped.
*/
struct dentry *autofs4_expire_indirect(struct super_block *sb,
@@ -336,7 +336,7 @@ struct dentry *autofs4_expire_indirect(s
now = jiffies;
timeout = sbi->exp_timeout;

- spin_lock(&dcache_lock);
+ spin_lock(&autofs4_lock);
spin_lock(&root->d_lock);
next = root->d_subdirs.next;

@@ -355,7 +355,7 @@ struct dentry *autofs4_expire_indirect(s
dentry = dget_dlock(dentry);
spin_unlock(&dentry->d_lock);
spin_unlock(&root->d_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);

spin_lock(&sbi->fs_lock);
ino = autofs4_dentry_ino(dentry);
@@ -420,12 +420,12 @@ struct dentry *autofs4_expire_indirect(s
next:
spin_unlock(&sbi->fs_lock);
dput(dentry);
- spin_lock(&dcache_lock);
+ spin_lock(&autofs4_lock);
spin_lock(&root->d_lock);
next = next->next;
}
spin_unlock(&root->d_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);
return NULL;

found:
@@ -435,13 +435,13 @@ found:
ino->flags |= AUTOFS_INF_EXPIRING;
init_completion(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
- spin_lock(&dcache_lock);
+ spin_lock(&autofs4_lock);
spin_lock(&expired->d_parent->d_lock);
spin_lock_nested(&expired->d_lock, DENTRY_D_LOCK_NESTED);
list_move(&expired->d_parent->d_subdirs, &expired->d_u.d_child);
spin_unlock(&expired->d_lock);
spin_unlock(&expired->d_parent->d_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);
return expired;
}

Index: linux-2.6/fs/autofs4/root.c
===================================================================
--- linux-2.6.orig/fs/autofs4/root.c
+++ linux-2.6/fs/autofs4/root.c
@@ -134,15 +134,15 @@ static int autofs4_dir_open(struct inode
* autofs file system so just let the libfs routines handle
* it.
*/
- spin_lock(&dcache_lock);
+ spin_lock(&autofs4_lock);
spin_lock(&dentry->d_lock);
if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);
return -ENOENT;
}
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);

out:
return dcache_dir_open(inode, file);
@@ -248,11 +248,11 @@ static void *autofs4_follow_link(struct
/* We trigger a mount for almost all flags */
lookup_type = autofs4_need_mount(nd->flags);
spin_lock(&sbi->fs_lock);
- spin_lock(&dcache_lock);
+ spin_lock(&autofs4_lock);
spin_lock(&dentry->d_lock);
if (!(lookup_type || ino->flags & AUTOFS_INF_PENDING)) {
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);
spin_unlock(&sbi->fs_lock);
goto follow;
}
@@ -274,7 +274,7 @@ static void *autofs4_follow_link(struct
goto follow;
}
spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);
spin_unlock(&sbi->fs_lock);
follow:
/*
@@ -476,7 +476,7 @@ static struct dentry *autofs4_lookup_exp
const unsigned char *str = name->name;
struct list_head *p, *head;

- spin_lock(&dcache_lock);
+ spin_lock(&autofs4_lock);
spin_lock(&sbi->lookup_lock);
head = &sbi->expiring_list;
list_for_each(p, head) {
Index: linux-2.6/fs/autofs4/waitq.c
===================================================================
--- linux-2.6.orig/fs/autofs4/waitq.c
+++ linux-2.6/fs/autofs4/waitq.c
@@ -194,14 +194,15 @@ static int autofs4_getpath(struct autofs
rename_retry:
buf = *name;
len = 0;
+
seq = read_seqbegin(&rename_lock);
rcu_read_lock();
- spin_lock(&dcache_lock);
+ spin_lock(&autofs4_lock);
for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent)
len += tmp->d_name.len + 1;

if (!len || --len > NAME_MAX) {
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);
rcu_read_unlock();
if (read_seqretry(&rename_lock, seq))
goto rename_retry;
@@ -217,7 +218,7 @@ rename_retry:
p -= tmp->d_name.len;
strncpy(p, tmp->d_name.name, tmp->d_name.len);
}
- spin_unlock(&dcache_lock);
+ spin_unlock(&autofs4_lock);
rcu_read_unlock();
if (read_seqretry(&rename_lock, seq))
goto rename_retry;
Index: linux-2.6/drivers/infiniband/hw/qib/qib_fs.c
===================================================================
--- linux-2.6.orig/drivers/infiniband/hw/qib/qib_fs.c
+++ linux-2.6/drivers/infiniband/hw/qib/qib_fs.c
@@ -451,17 +451,14 @@ static int remove_file(struct dentry *pa
goto bail;
}

- spin_lock(&dcache_lock);
spin_lock(&tmp->d_lock);
if (!(d_unhashed(tmp) && tmp->d_inode)) {
dget_locked_dlock(tmp);
__d_drop(tmp);
spin_unlock(&tmp->d_lock);
- spin_unlock(&dcache_lock);
simple_unlink(parent->d_inode, tmp);
} else {
spin_unlock(&tmp->d_lock);
- spin_unlock(&dcache_lock);
}

ret = 0;
Index: linux-2.6/fs/ceph/dir.c
===================================================================
--- linux-2.6.orig/fs/ceph/dir.c
+++ linux-2.6/fs/ceph/dir.c
@@ -111,7 +111,6 @@ static int __dcache_readdir(struct file
dout("__dcache_readdir %p at %llu (last %p)\n", dir, filp->f_pos,
last);

- spin_lock(&dcache_lock);
spin_lock(&parent->d_lock);

/* start at beginning? */
@@ -155,7 +154,6 @@ more:
dget_dlock(dentry);
spin_unlock(&dentry->d_lock);
spin_unlock(&parent->d_lock);
- spin_unlock(&dcache_lock);
spin_unlock(&inode->i_lock);

dout(" %llu (%llu) dentry %p %.*s %p\n", di->offset, filp->f_pos,
@@ -178,7 +176,6 @@ more:
}

spin_lock(&inode->i_lock);
- spin_lock(&dcache_lock);
spin_lock(&parent->d_lock);

last = dentry;
@@ -189,7 +186,7 @@ more:
p = p->prev;
filp->f_pos++;

- /* make sure a dentry wasn't dropped while we didn't have dcache_lock */
+ /* make sure a dentry wasn't dropped while we didn't have parent->d_lock */
if ((ceph_inode(dir)->i_ceph_flags & CEPH_I_COMPLETE))
goto more;
dout(" lost I_COMPLETE on %p; falling back to mds\n", dir);
@@ -197,7 +194,6 @@ more:

out_unlock:
spin_unlock(&parent->d_lock);
- spin_unlock(&dcache_lock);

if (last) {
spin_unlock(&inode->i_lock);
Index: linux-2.6/fs/ceph/inode.c
===================================================================
--- linux-2.6.orig/fs/ceph/inode.c
+++ linux-2.6/fs/ceph/inode.c
@@ -825,7 +825,6 @@ static void ceph_set_dentry_offset(struc
di->offset = ceph_inode(inode)->i_max_offset++;
spin_unlock(&inode->i_lock);

- spin_lock(&dcache_lock);
spin_lock(&dir->d_lock);
spin_lock_nested(&dn->d_lock, DENTRY_D_LOCK_NESTED);
list_move(&dn->d_u.d_child, &dir->d_subdirs);
@@ -833,7 +832,6 @@ static void ceph_set_dentry_offset(struc
dn->d_u.d_child.prev, dn->d_u.d_child.next);
spin_unlock(&dn->d_lock);
spin_unlock(&dir->d_lock);
- spin_unlock(&dcache_lock);
}

/*
@@ -1213,13 +1211,11 @@ retry_lookup:
goto retry_lookup;
} else {
/* reorder parent's d_subdirs */
- spin_lock(&dcache_lock);
spin_lock(&parent->d_lock);
spin_lock_nested(&dn->d_lock, DENTRY_D_LOCK_NESTED);
list_move(&dn->d_u.d_child, &parent->d_subdirs);
spin_unlock(&dn->d_lock);
spin_unlock(&parent->d_lock);
- spin_unlock(&dcache_lock);
}

di = dn->d_fsdata;