vfs: spread struct mount - work with counters
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namespace.c b/fs/namespace.c
index ec798e7..a13165c 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -141,13 +141,13 @@
/*
* vfsmount lock must be held for read
*/
-static inline void mnt_add_count(struct vfsmount *mnt, int n)
+static inline void mnt_add_count(struct mount *mnt, int n)
{
#ifdef CONFIG_SMP
- this_cpu_add(mnt->mnt_pcp->mnt_count, n);
+ this_cpu_add(mnt->mnt.mnt_pcp->mnt_count, n);
#else
preempt_disable();
- mnt->mnt_count += n;
+ mnt->mnt.mnt_count += n;
preempt_enable();
#endif
}
@@ -155,19 +155,19 @@
/*
* vfsmount lock must be held for write
*/
-unsigned int mnt_get_count(struct vfsmount *mnt)
+unsigned int mnt_get_count(struct mount *mnt)
{
#ifdef CONFIG_SMP
unsigned int count = 0;
int cpu;
for_each_possible_cpu(cpu) {
- count += per_cpu_ptr(mnt->mnt_pcp, cpu)->mnt_count;
+ count += per_cpu_ptr(mnt->mnt.mnt_pcp, cpu)->mnt_count;
}
return count;
#else
- return mnt->mnt_count;
+ return mnt->mnt.mnt_count;
#endif
}
@@ -253,32 +253,32 @@
}
EXPORT_SYMBOL_GPL(__mnt_is_readonly);
-static inline void mnt_inc_writers(struct vfsmount *mnt)
+static inline void mnt_inc_writers(struct mount *mnt)
{
#ifdef CONFIG_SMP
- this_cpu_inc(mnt->mnt_pcp->mnt_writers);
+ this_cpu_inc(mnt->mnt.mnt_pcp->mnt_writers);
#else
- mnt->mnt_writers++;
+ mnt->mnt.mnt_writers++;
#endif
}
-static inline void mnt_dec_writers(struct vfsmount *mnt)
+static inline void mnt_dec_writers(struct mount *mnt)
{
#ifdef CONFIG_SMP
- this_cpu_dec(mnt->mnt_pcp->mnt_writers);
+ this_cpu_dec(mnt->mnt.mnt_pcp->mnt_writers);
#else
- mnt->mnt_writers--;
+ mnt->mnt.mnt_writers--;
#endif
}
-static unsigned int mnt_get_writers(struct vfsmount *mnt)
+static unsigned int mnt_get_writers(struct mount *mnt)
{
#ifdef CONFIG_SMP
unsigned int count = 0;
int cpu;
for_each_possible_cpu(cpu) {
- count += per_cpu_ptr(mnt->mnt_pcp, cpu)->mnt_writers;
+ count += per_cpu_ptr(mnt->mnt.mnt_pcp, cpu)->mnt_writers;
}
return count;
@@ -297,7 +297,7 @@
*/
/**
* mnt_want_write - get write access to a mount
- * @mnt: the mount on which to take a write
+ * @m: the mount on which to take a write
*
* This tells the low-level filesystem that a write is
* about to be performed to it, and makes sure that
@@ -305,8 +305,9 @@
* the write operation is finished, mnt_drop_write()
* must be called. This is effectively a refcount.
*/
-int mnt_want_write(struct vfsmount *mnt)
+int mnt_want_write(struct vfsmount *m)
{
+ struct mount *mnt = real_mount(m);
int ret = 0;
preempt_disable();
@@ -317,7 +318,7 @@
* incremented count after it has set MNT_WRITE_HOLD.
*/
smp_mb();
- while (mnt->mnt_flags & MNT_WRITE_HOLD)
+ while (mnt->mnt.mnt_flags & MNT_WRITE_HOLD)
cpu_relax();
/*
* After the slowpath clears MNT_WRITE_HOLD, mnt_is_readonly will
@@ -325,7 +326,7 @@
* MNT_WRITE_HOLD is cleared.
*/
smp_rmb();
- if (__mnt_is_readonly(mnt)) {
+ if (__mnt_is_readonly(m)) {
mnt_dec_writers(mnt);
ret = -EROFS;
goto out;
@@ -354,7 +355,7 @@
if (__mnt_is_readonly(mnt))
return -EROFS;
preempt_disable();
- mnt_inc_writers(mnt);
+ mnt_inc_writers(real_mount(mnt));
preempt_enable();
return 0;
}
@@ -388,7 +389,7 @@
void mnt_drop_write(struct vfsmount *mnt)
{
preempt_disable();
- mnt_dec_writers(mnt);
+ mnt_dec_writers(real_mount(mnt));
preempt_enable();
}
EXPORT_SYMBOL_GPL(mnt_drop_write);
@@ -399,12 +400,12 @@
}
EXPORT_SYMBOL(mnt_drop_write_file);
-static int mnt_make_readonly(struct vfsmount *mnt)
+static int mnt_make_readonly(struct mount *mnt)
{
int ret = 0;
br_write_lock(vfsmount_lock);
- mnt->mnt_flags |= MNT_WRITE_HOLD;
+ mnt->mnt.mnt_flags |= MNT_WRITE_HOLD;
/*
* After storing MNT_WRITE_HOLD, we'll read the counters. This store
* should be visible before we do.
@@ -430,21 +431,21 @@
if (mnt_get_writers(mnt) > 0)
ret = -EBUSY;
else
- mnt->mnt_flags |= MNT_READONLY;
+ mnt->mnt.mnt_flags |= MNT_READONLY;
/*
* MNT_READONLY must become visible before ~MNT_WRITE_HOLD, so writers
* that become unheld will see MNT_READONLY.
*/
smp_wmb();
- mnt->mnt_flags &= ~MNT_WRITE_HOLD;
+ mnt->mnt.mnt_flags &= ~MNT_WRITE_HOLD;
br_write_unlock(vfsmount_lock);
return ret;
}
-static void __mnt_unmake_readonly(struct vfsmount *mnt)
+static void __mnt_unmake_readonly(struct mount *mnt)
{
br_write_lock(vfsmount_lock);
- mnt->mnt_flags &= ~MNT_READONLY;
+ mnt->mnt.mnt_flags &= ~MNT_READONLY;
br_write_unlock(vfsmount_lock);
}
@@ -590,18 +591,18 @@
list_add_tail(&mnt->mnt.mnt_child, &path->mnt->mnt_mounts);
}
-static inline void __mnt_make_longterm(struct vfsmount *mnt)
+static inline void __mnt_make_longterm(struct mount *mnt)
{
#ifdef CONFIG_SMP
- atomic_inc(&mnt->mnt_longterm);
+ atomic_inc(&mnt->mnt.mnt_longterm);
#endif
}
/* needs vfsmount lock for write */
-static inline void __mnt_make_shortterm(struct vfsmount *mnt)
+static inline void __mnt_make_shortterm(struct mount *mnt)
{
#ifdef CONFIG_SMP
- atomic_dec(&mnt->mnt_longterm);
+ atomic_dec(&mnt->mnt.mnt_longterm);
#endif
}
@@ -611,15 +612,15 @@
static void commit_tree(struct mount *mnt)
{
struct mount *parent = mnt->mnt_parent;
- struct vfsmount *m;
+ struct mount *m;
LIST_HEAD(head);
struct mnt_namespace *n = parent->mnt.mnt_ns;
BUG_ON(parent == mnt);
list_add_tail(&head, &mnt->mnt.mnt_list);
- list_for_each_entry(m, &head, mnt_list) {
- m->mnt_ns = n;
+ list_for_each_entry(m, &head, mnt.mnt_list) {
+ m->mnt.mnt_ns = n;
__mnt_make_longterm(m);
}
@@ -740,9 +741,10 @@
return NULL;
}
-static inline void mntfree(struct vfsmount *mnt)
+static inline void mntfree(struct mount *mnt)
{
- struct super_block *sb = mnt->mnt_sb;
+ struct vfsmount *m = &mnt->mnt;
+ struct super_block *sb = m->mnt_sb;
/*
* This probably indicates that somebody messed
@@ -755,18 +757,19 @@
* so mnt_get_writers() below is safe.
*/
WARN_ON(mnt_get_writers(mnt));
- fsnotify_vfsmount_delete(mnt);
- dput(mnt->mnt_root);
- free_vfsmnt(real_mount(mnt));
+ fsnotify_vfsmount_delete(m);
+ dput(m->mnt_root);
+ free_vfsmnt(mnt);
deactivate_super(sb);
}
-static void mntput_no_expire(struct vfsmount *mnt)
+static void mntput_no_expire(struct vfsmount *m)
{
+ struct mount *mnt = real_mount(m);
put_again:
#ifdef CONFIG_SMP
br_read_lock(vfsmount_lock);
- if (likely(atomic_read(&mnt->mnt_longterm))) {
+ if (likely(atomic_read(&mnt->mnt.mnt_longterm))) {
mnt_add_count(mnt, -1);
br_read_unlock(vfsmount_lock);
return;
@@ -785,11 +788,11 @@
return;
br_write_lock(vfsmount_lock);
#endif
- if (unlikely(mnt->mnt_pinned)) {
- mnt_add_count(mnt, mnt->mnt_pinned + 1);
- mnt->mnt_pinned = 0;
+ if (unlikely(mnt->mnt.mnt_pinned)) {
+ mnt_add_count(mnt, mnt->mnt.mnt_pinned + 1);
+ mnt->mnt.mnt_pinned = 0;
br_write_unlock(vfsmount_lock);
- acct_auto_close_mnt(mnt);
+ acct_auto_close_mnt(m);
goto put_again;
}
br_write_unlock(vfsmount_lock);
@@ -810,7 +813,7 @@
struct vfsmount *mntget(struct vfsmount *mnt)
{
if (mnt)
- mnt_add_count(mnt, 1);
+ mnt_add_count(real_mount(mnt), 1);
return mnt;
}
EXPORT_SYMBOL(mntget);
@@ -827,7 +830,7 @@
{
br_write_lock(vfsmount_lock);
if (mnt->mnt_pinned) {
- mnt_add_count(mnt, 1);
+ mnt_add_count(real_mount(mnt), 1);
mnt->mnt_pinned--;
}
br_write_unlock(vfsmount_lock);
@@ -1150,7 +1153,7 @@
/* write lock needed for mnt_get_count */
br_write_lock(vfsmount_lock);
for (p = real_mount(mnt); p; p = next_mnt(p, mnt)) {
- actual_refs += mnt_get_count(&p->mnt);
+ actual_refs += mnt_get_count(p);
minimum_refs += 2;
}
br_write_unlock(vfsmount_lock);
@@ -1234,7 +1237,7 @@
list_del_init(&p->mnt.mnt_list);
__touch_mnt_namespace(p->mnt.mnt_ns);
p->mnt.mnt_ns = NULL;
- __mnt_make_shortterm(&p->mnt);
+ __mnt_make_shortterm(p);
list_del_init(&p->mnt.mnt_child);
if (mnt_has_parent(p)) {
p->mnt_parent->mnt.mnt_ghosts++;
@@ -1273,7 +1276,7 @@
* all race cases, but it's a slowpath.
*/
br_write_lock(vfsmount_lock);
- if (mnt_get_count(&mnt->mnt) != 2) {
+ if (mnt_get_count(mnt) != 2) {
br_write_unlock(vfsmount_lock);
return -EBUSY;
}
@@ -1798,9 +1801,9 @@
return 0;
if (readonly_request)
- error = mnt_make_readonly(mnt);
+ error = mnt_make_readonly(real_mount(mnt));
else
- __mnt_unmake_readonly(mnt);
+ __mnt_unmake_readonly(real_mount(mnt));
return error;
}
@@ -2034,7 +2037,7 @@
/* The new mount record should have at least 2 refs to prevent it being
* expired before we get a chance to add it
*/
- BUG_ON(mnt_get_count(m) < 2);
+ BUG_ON(mnt_get_count(real_mount(m)) < 2);
if (m->mnt_sb == path->mnt->mnt_sb &&
m->mnt_root == path->dentry) {
@@ -2365,16 +2368,17 @@
void mnt_make_longterm(struct vfsmount *mnt)
{
- __mnt_make_longterm(mnt);
+ __mnt_make_longterm(real_mount(mnt));
}
-void mnt_make_shortterm(struct vfsmount *mnt)
+void mnt_make_shortterm(struct vfsmount *m)
{
#ifdef CONFIG_SMP
- if (atomic_add_unless(&mnt->mnt_longterm, -1, 1))
+ struct mount *mnt = real_mount(m);
+ if (atomic_add_unless(&mnt->mnt.mnt_longterm, -1, 1))
return;
br_write_lock(vfsmount_lock);
- atomic_dec(&mnt->mnt_longterm);
+ atomic_dec(&mnt->mnt.mnt_longterm);
br_write_unlock(vfsmount_lock);
#endif
}
@@ -2418,17 +2422,17 @@
q = new;
while (p) {
q->mnt.mnt_ns = new_ns;
- __mnt_make_longterm(&q->mnt);
+ __mnt_make_longterm(q);
if (fs) {
if (&p->mnt == fs->root.mnt) {
fs->root.mnt = mntget(&q->mnt);
- __mnt_make_longterm(&q->mnt);
+ __mnt_make_longterm(q);
mnt_make_shortterm(&p->mnt);
rootmnt = &p->mnt;
}
if (&p->mnt == fs->pwd.mnt) {
fs->pwd.mnt = mntget(&q->mnt);
- __mnt_make_longterm(&q->mnt);
+ __mnt_make_longterm(q);
mnt_make_shortterm(&p->mnt);
pwdmnt = &p->mnt;
}
@@ -2474,7 +2478,7 @@
new_ns = alloc_mnt_ns();
if (!IS_ERR(new_ns)) {
mnt->mnt_ns = new_ns;
- __mnt_make_longterm(mnt);
+ __mnt_make_longterm(real_mount(mnt));
new_ns->root = mnt;
list_add(&new_ns->list, &new_ns->root->mnt_list);
} else {