return dentry->d_name.name != dentry->d_iname;
}
-/*
- * Make sure other CPUs see the inode attached before the type is set.
- */
static inline void __d_set_inode_and_type(struct dentry *dentry,
struct inode *inode,
unsigned type_flags)
unsigned flags;
dentry->d_inode = inode;
- smp_wmb();
flags = READ_ONCE(dentry->d_flags);
flags &= ~(DCACHE_ENTRY_TYPE | DCACHE_FALLTHRU);
flags |= type_flags;
WRITE_ONCE(dentry->d_flags, flags);
}
-/*
- * Ideally, we want to make sure that other CPUs see the flags cleared before
- * the inode is detached, but this is really a violation of RCU principles
- * since the ordering suggests we should always set inode before flags.
- *
- * We should instead replace or discard the entire dentry - but that sucks
- * performancewise on mass deletion/rename.
- */
static inline void __d_clear_type_and_inode(struct dentry *dentry)
{
unsigned flags = READ_ONCE(dentry->d_flags);
flags &= ~(DCACHE_ENTRY_TYPE | DCACHE_FALLTHRU);
WRITE_ONCE(dentry->d_flags, flags);
- smp_wmb();
dentry->d_inode = NULL;
}
}
/**
- * dentry_rcuwalk_barrier - invalidate in-progress rcu-walk lookups
+ * dentry_rcuwalk_invalidate - invalidate in-progress rcu-walk lookups
* @dentry: the target dentry
* After this call, in-progress rcu-walk path lookup will fail. This
* should be called after unhashing, and after changing d_inode (if
* the dentry has not already been unhashed).
*/
-static inline void dentry_rcuwalk_barrier(struct dentry *dentry)
+static inline void dentry_rcuwalk_invalidate(struct dentry *dentry)
{
- assert_spin_locked(&dentry->d_lock);
- /* Go through a barrier */
- write_seqcount_barrier(&dentry->d_seq);
+ lockdep_assert_held(&dentry->d_lock);
+ /* Go through am invalidation barrier */
+ write_seqcount_invalidate(&dentry->d_seq);
}
/*
__releases(dentry->d_inode->i_lock)
{
struct inode *inode = dentry->d_inode;
+
+ raw_write_seqcount_begin(&dentry->d_seq);
__d_clear_type_and_inode(dentry);
hlist_del_init(&dentry->d_u.d_alias);
- dentry_rcuwalk_barrier(dentry);
+ raw_write_seqcount_end(&dentry->d_seq);
spin_unlock(&dentry->d_lock);
spin_unlock(&inode->i_lock);
if (!inode->i_nlink)
__hlist_bl_del(&dentry->d_hash);
dentry->d_hash.pprev = NULL;
hlist_bl_unlock(b);
- dentry_rcuwalk_barrier(dentry);
+ dentry_rcuwalk_invalidate(dentry);
}
}
EXPORT_SYMBOL(__d_drop);
failed:
spin_unlock(&dentry->d_lock);
- cpu_chill();
return dentry; /* try again with same dentry */
}
*/
void dput(struct dentry *dentry)
{
+ struct dentry *parent;
+
if (unlikely(!dentry))
return;
repeat:
+ might_sleep();
+
rcu_read_lock();
if (likely(fast_dput(dentry))) {
rcu_read_unlock();
return;
kill_it:
- dentry = dentry_kill(dentry);
- if (dentry)
+ parent = dentry_kill(dentry);
+ if (parent) {
+ int r;
+
+ if (parent == dentry) {
+ /* the task with the highest priority won't schedule */
+ r = cond_resched();
+ if (!r)
+ cpu_chill();
+ } else {
+ dentry = parent;
+ }
goto repeat;
+ }
}
EXPORT_SYMBOL(dput);
}
spin_lock(&dentry->d_lock);
if (!d_unlinked(dentry)) {
- dentry->d_flags |= DCACHE_MOUNTED;
- ret = 0;
+ ret = -EBUSY;
+ if (!d_mountpoint(dentry)) {
+ dentry->d_flags |= DCACHE_MOUNTED;
+ ret = 0;
+ }
}
spin_unlock(&dentry->d_lock);
out:
struct dentry *dentry = __d_alloc(parent->d_sb, name);
if (!dentry)
return NULL;
-
+ dentry->d_flags |= DCACHE_RCUACCESS;
spin_lock(&parent->d_lock);
/*
* don't need child lock because it is not subject
DCACHE_OP_COMPARE |
DCACHE_OP_REVALIDATE |
DCACHE_OP_WEAK_REVALIDATE |
- DCACHE_OP_DELETE ));
+ DCACHE_OP_DELETE |
+ DCACHE_OP_SELECT_INODE |
+ DCACHE_OP_REAL));
dentry->d_op = op;
if (!op)
return;
dentry->d_flags |= DCACHE_OP_DELETE;
if (op->d_prune)
dentry->d_flags |= DCACHE_OP_PRUNE;
+ if (op->d_select_inode)
+ dentry->d_flags |= DCACHE_OP_SELECT_INODE;
+ if (op->d_real)
+ dentry->d_flags |= DCACHE_OP_REAL;
}
EXPORT_SYMBOL(d_set_d_op);
spin_lock(&dentry->d_lock);
if (inode)
hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry);
+ raw_write_seqcount_begin(&dentry->d_seq);
__d_set_inode_and_type(dentry, inode, add_flags);
- dentry_rcuwalk_barrier(dentry);
+ raw_write_seqcount_end(&dentry->d_seq);
spin_unlock(&dentry->d_lock);
fsnotify_d_instantiate(dentry, inode);
}
{
BUG_ON(!d_unhashed(entry));
hlist_bl_lock(b);
- entry->d_flags |= DCACHE_RCUACCESS;
hlist_bl_add_head_rcu(&entry->d_hash, b);
hlist_bl_unlock(b);
}
/* ... and switch them in the tree */
if (IS_ROOT(dentry)) {
/* splicing a tree */
+ dentry->d_flags |= DCACHE_RCUACCESS;
dentry->d_parent = target->d_parent;
target->d_parent = target;
list_del_init(&target->d_child);
* This helper attempts to cope with remotely renamed directories
*
* It assumes that the caller is already holding
- * dentry->d_parent->d_inode->i_mutex, inode->i_lock and rename_lock
+ * dentry->d_parent->d_inode->i_mutex, and rename_lock
*
* Note: If ever the locking in lock_rename() changes, then please
* remember to update this too...
__d_move(alias, dentry, false);
ret = 0;
out_err:
- spin_unlock(&inode->i_lock);
if (m2)
mutex_unlock(m2);
if (m1)
if (S_ISDIR(inode->i_mode)) {
struct dentry *new = __d_find_any_alias(inode);
if (unlikely(new)) {
+ /* The reference to new ensures it remains an alias */
+ spin_unlock(&inode->i_lock);
write_seqlock(&rename_lock);
if (unlikely(d_ancestor(new, dentry))) {
write_sequnlock(&rename_lock);
- spin_unlock(&inode->i_lock);
dput(new);
new = ERR_PTR(-ELOOP);
pr_warn_ratelimited(
} else {
__d_move(new, dentry, false);
write_sequnlock(&rename_lock);
- spin_unlock(&inode->i_lock);
security_d_instantiate(new, inode);
}
iput(inode);
if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) {
struct mount *parent = ACCESS_ONCE(mnt->mnt_parent);
+ /* Escaped? */
+ if (dentry != vfsmnt->mnt_root) {
+ bptr = *buffer;
+ blen = *buflen;
+ error = 3;
+ break;
+ }
/* Global root? */
if (mnt != parent) {
dentry = ACCESS_ONCE(mnt->mnt_mountpoint);
inode_init_early();
}
-void __init vfs_caches_init(unsigned long mempages)
+void __init vfs_caches_init(void)
{
- unsigned long reserve;
-
- /* Base hash sizes on available memory, with a reserve equal to
- 150% of current kernel size */
-
- reserve = min((mempages - nr_free_pages()) * 3/2, mempages - 1);
- mempages -= reserve;
-
names_cachep = kmem_cache_create("names_cache", PATH_MAX, 0,
SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
dcache_init();
inode_init();
- files_init(mempages);
+ files_init();
+ files_maxfiles_init();
mnt_init();
bdev_cache_init();
chrdev_init();