fs: dcache rationalise dget variants
dget_locked was a shortcut to avoid the lazy lru manipulation when we already
held dcache_lock (lru manipulation was relatively cheap at that point).
However, how that the lru lock is an innermost one, we never hold it at any
caller, so the lock cost can now be avoided. We already have well working lazy
dcache LRU, so it should be fine to defer LRU manipulations to scan time.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c
index 2662b50..03185de 100644
--- a/arch/powerpc/platforms/cell/spufs/inode.c
+++ b/arch/powerpc/platforms/cell/spufs/inode.c
@@ -161,7 +161,7 @@
list_for_each_entry_safe(dentry, tmp, &dir->d_subdirs, d_u.d_child) {
spin_lock(&dentry->d_lock);
if (!(d_unhashed(dentry)) && dentry->d_inode) {
- dget_locked_dlock(dentry);
+ dget_dlock(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
simple_unlink(dir->d_inode, dentry);
diff --git a/drivers/infiniband/hw/ipath/ipath_fs.c b/drivers/infiniband/hw/ipath/ipath_fs.c
index 925e882..31ae1b1 100644
--- a/drivers/infiniband/hw/ipath/ipath_fs.c
+++ b/drivers/infiniband/hw/ipath/ipath_fs.c
@@ -279,7 +279,7 @@
spin_lock(&tmp->d_lock);
if (!(d_unhashed(tmp) && tmp->d_inode)) {
- dget_locked_dlock(tmp);
+ dget_dlock(tmp);
__d_drop(tmp);
spin_unlock(&tmp->d_lock);
simple_unlink(parent->d_inode, tmp);
diff --git a/drivers/infiniband/hw/qib/qib_fs.c b/drivers/infiniband/hw/qib/qib_fs.c
index 49af4a6..df7fa25 100644
--- a/drivers/infiniband/hw/qib/qib_fs.c
+++ b/drivers/infiniband/hw/qib/qib_fs.c
@@ -455,7 +455,7 @@
spin_lock(&tmp->d_lock);
if (!(d_unhashed(tmp) && tmp->d_inode)) {
- dget_locked_dlock(tmp);
+ dget_dlock(tmp);
__d_drop(tmp);
spin_unlock(&tmp->d_lock);
simple_unlink(parent->d_inode, tmp);
diff --git a/drivers/staging/smbfs/cache.c b/drivers/staging/smbfs/cache.c
index 75dfd40..f2a1323 100644
--- a/drivers/staging/smbfs/cache.c
+++ b/drivers/staging/smbfs/cache.c
@@ -102,7 +102,7 @@
dent = list_entry(next, struct dentry, d_u.d_child);
if ((unsigned long)dent->d_fsdata == fpos) {
if (dent->d_inode)
- dget_locked(dent);
+ dget(dent);
else
dent = NULL;
goto out_unlock;
diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c
index fb3a55f..c83f476 100644
--- a/fs/configfs/inode.c
+++ b/fs/configfs/inode.c
@@ -252,7 +252,7 @@
if (dentry) {
spin_lock(&dentry->d_lock);
if (!(d_unhashed(dentry) && dentry->d_inode)) {
- dget_locked_dlock(dentry);
+ dget_dlock(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
simple_unlink(parent->d_inode, dentry);
diff --git a/fs/dcache.c b/fs/dcache.c
index 01f0167..b4d2e28 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -429,33 +429,18 @@
EXPORT_SYMBOL(d_invalidate);
/* This must be called with d_lock held */
-static inline struct dentry * __dget_locked_dlock(struct dentry *dentry)
+static inline void __dget_dlock(struct dentry *dentry)
{
dentry->d_count++;
- dentry_lru_del(dentry);
- return dentry;
}
-/* This must be called with d_lock held */
-static inline struct dentry * __dget_locked(struct dentry *dentry)
+static inline void __dget(struct dentry *dentry)
{
spin_lock(&dentry->d_lock);
- __dget_locked_dlock(dentry);
+ __dget_dlock(dentry);
spin_unlock(&dentry->d_lock);
- return dentry;
}
-struct dentry * dget_locked_dlock(struct dentry *dentry)
-{
- return __dget_locked_dlock(dentry);
-}
-
-struct dentry * dget_locked(struct dentry *dentry)
-{
- return __dget_locked(dentry);
-}
-EXPORT_SYMBOL(dget_locked);
-
struct dentry *dget_parent(struct dentry *dentry)
{
struct dentry *ret;
@@ -512,7 +497,7 @@
(alias->d_flags & DCACHE_DISCONNECTED)) {
discon_alias = alias;
} else if (!want_discon) {
- __dget_locked_dlock(alias);
+ __dget_dlock(alias);
spin_unlock(&alias->d_lock);
return alias;
}
@@ -525,7 +510,7 @@
if (S_ISDIR(inode->i_mode) || !d_unhashed(alias)) {
if (IS_ROOT(alias) &&
(alias->d_flags & DCACHE_DISCONNECTED)) {
- __dget_locked_dlock(alias);
+ __dget_dlock(alias);
spin_unlock(&alias->d_lock);
return alias;
}
@@ -561,7 +546,7 @@
list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
spin_lock(&dentry->d_lock);
if (!dentry->d_count) {
- __dget_locked_dlock(dentry);
+ __dget_dlock(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_inode_lock);
@@ -1257,7 +1242,8 @@
* don't need child lock because it is not subject
* to concurrency here
*/
- dentry->d_parent = dget_dlock(parent);
+ __dget_dlock(parent);
+ dentry->d_parent = parent;
dentry->d_sb = parent->d_sb;
list_add(&dentry->d_u.d_child, &parent->d_subdirs);
spin_unlock(&parent->d_lock);
@@ -1360,7 +1346,7 @@
continue;
if (memcmp(qstr->name, name, len))
continue;
- dget_locked(alias);
+ __dget(alias);
return alias;
}
@@ -1613,7 +1599,7 @@
* reference to it, move it in place and use it.
*/
new = list_entry(inode->i_dentry.next, struct dentry, d_alias);
- dget_locked(new);
+ __dget(new);
spin_unlock(&dcache_inode_lock);
security_d_instantiate(found, inode);
d_move(new, found);
@@ -1789,7 +1775,7 @@
list_for_each_entry(child, &dparent->d_subdirs, d_u.d_child) {
if (dentry == child) {
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
- __dget_locked_dlock(dentry);
+ __dget_dlock(dentry);
spin_unlock(&dentry->d_lock);
spin_unlock(&dparent->d_lock);
return 1;
diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index 53a5c08..f06a940 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -49,7 +49,7 @@
spin_lock(&dcache_inode_lock);
list_for_each_entry(dentry, &result->d_inode->i_dentry, d_alias) {
- dget_locked(dentry);
+ dget(dentry);
spin_unlock(&dcache_inode_lock);
if (toput)
dput(toput);
diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index de15c53..0ba3cdc 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -397,7 +397,7 @@
dent = list_entry(next, struct dentry, d_u.d_child);
if ((unsigned long)dent->d_fsdata == fpos) {
if (dent->d_inode)
- dget_locked(dent);
+ dget(dent);
else
dent = NULL;
spin_unlock(&parent->d_lock);
diff --git a/fs/ocfs2/dcache.c b/fs/ocfs2/dcache.c
index b7de749..4d54c60 100644
--- a/fs/ocfs2/dcache.c
+++ b/fs/ocfs2/dcache.c
@@ -178,7 +178,7 @@
mlog(0, "dentry found: %.*s\n",
dentry->d_name.len, dentry->d_name.name);
- dget_locked_dlock(dentry);
+ dget_dlock(dentry);
spin_unlock(&dentry->d_lock);
break;
}
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index a2ceb94..ca64868 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -287,23 +287,17 @@
/* Allocation counts.. */
/**
- * dget, dget_locked - get a reference to a dentry
+ * dget, dget_dlock - get a reference to a dentry
* @dentry: dentry to get a reference to
*
* Given a dentry or %NULL pointer increment the reference count
* if appropriate and return the dentry. A dentry will not be
- * destroyed when it has references. dget() should never be
- * called for dentries with zero reference counter. For these cases
- * (preferably none, functions in dcache.c are sufficient for normal
- * needs and they take necessary precautions) you should hold d_lock
- * and call dget_dlock() instead of dget().
+ * destroyed when it has references.
*/
static inline struct dentry *dget_dlock(struct dentry *dentry)
{
- if (dentry) {
- BUG_ON(!dentry->d_count);
+ if (dentry)
dentry->d_count++;
- }
return dentry;
}
@@ -317,9 +311,6 @@
return dentry;
}
-extern struct dentry * dget_locked(struct dentry *);
-extern struct dentry * dget_locked_dlock(struct dentry *);
-
extern struct dentry *dget_parent(struct dentry *dentry);
/**
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 1864cb6..9f41470 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -887,7 +887,7 @@
/* This should never be called on a cgroup
* directory with child cgroups */
BUG_ON(d->d_inode->i_mode & S_IFDIR);
- dget_locked_dlock(d);
+ dget_dlock(d);
spin_unlock(&d->d_lock);
spin_unlock(&dentry->d_lock);
d_delete(d);
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 2285d69..43deac2 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -1154,7 +1154,7 @@
list_del_init(node);
if (d->d_inode) {
- dget_locked_dlock(d);
+ dget_dlock(d);
spin_unlock(&de->d_lock);
spin_unlock(&d->d_lock);
d_delete(d);