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Revert "kernfs: invoke kernfs_unmap_bin_file() directly from __kernfs_remove()" 

This reverts commit f601f9a2bf.

Tejun writes:
        I'm sorry but can you please revert the whole series?
        get_active() waiting while a node is deactivated has potential
        to lead to deadlock and that deactivate/reactivate interface is
        something fundamentally flawed and that cgroup will have to work
        with the remove_self() like everybody else.  IOW, I think the
        first posting was correct.

Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hifive-unleashed-5.1
Greg Kroah-Hartman 2014-01-13 14:27:16 -08:00
parent 7653fe9d6c
commit 55f6e30d0a
3 changed files with 14 additions and 35 deletions
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42
fs/kernfs/dir.c
View File

@ -121,17 +121,13 @@ static int kernfs_link_sibling(struct kernfs_node *kn)
* Locking:
* mutex_lock(kernfs_mutex)
*/
static bool kernfs_unlink_sibling(struct kernfs_node *kn)
static void kernfs_unlink_sibling(struct kernfs_node *kn)
{
if (RB_EMPTY_NODE(&kn->rb))
return false;
if (kernfs_type(kn) == KERNFS_DIR)
kn->parent->dir.subdirs--;
rb_erase(&kn->rb, &kn->parent->dir.children);
RB_CLEAR_NODE(&kn->rb);
return true;
}
/**
@ -500,6 +496,7 @@ void kernfs_addrm_finish(struct kernfs_addrm_cxt *acxt)
acxt->removed = kn->u.removed_list;
kernfs_unmap_bin_file(kn);
kernfs_put(kn);
}
}
@ -857,44 +854,23 @@ static void __kernfs_remove(struct kernfs_addrm_cxt *acxt,
/* unlink the subtree node-by-node */
do {
struct kernfs_iattrs *ps_iattr;
pos = kernfs_leftmost_descendant(kn);
/*
* We're gonna release kernfs_mutex to unmap bin files,
* Make sure @pos doesn't go away inbetween.
*/
kernfs_get(pos);
/*
* This must be come before unlinking; otherwise, when
* there are multiple removers, some may finish before
* unmapping is complete.
*/
if (pos->flags & KERNFS_HAS_MMAP) {
mutex_unlock(&kernfs_mutex);
kernfs_unmap_file(pos);
mutex_lock(&kernfs_mutex);
}
/*
* kernfs_unlink_sibling() succeeds once per node. Use it
* to decide who's responsible for cleanups.
*/
if (!pos->parent || kernfs_unlink_sibling(pos)) {
struct kernfs_iattrs *ps_iattr =
pos->parent ? pos->parent->iattr : NULL;
if (pos->parent) {
kernfs_unlink_sibling(pos);
/* update timestamps on the parent */
ps_iattr = pos->parent->iattr;
if (ps_iattr) {
ps_iattr->ia_iattr.ia_ctime = CURRENT_TIME;
ps_iattr->ia_iattr.ia_mtime = CURRENT_TIME;
}
pos->u.removed_list = acxt->removed;
acxt->removed = pos;
}
kernfs_put(pos);
pos->u.removed_list = acxt->removed;
acxt->removed = pos;
} while (pos != kn);
}

5
fs/kernfs/file.c
View File

@ -700,11 +700,14 @@ static int kernfs_fop_release(struct inode *inode, struct file *filp)
return 0;
}
void kernfs_unmap_file(struct kernfs_node *kn)
void kernfs_unmap_bin_file(struct kernfs_node *kn)
{
struct kernfs_open_node *on;
struct kernfs_open_file *of;
if (!(kn->flags & KERNFS_HAS_MMAP))
return;
spin_lock_irq(&kernfs_open_node_lock);
on = kn->attr.open;
if (on)

2
fs/kernfs/kernfs-internal.h
View File

@ -113,7 +113,7 @@ struct kernfs_node *kernfs_new_node(struct kernfs_root *root, const char *name,
*/
extern const struct file_operations kernfs_file_fops;
void kernfs_unmap_file(struct kernfs_node *kn);
void kernfs_unmap_bin_file(struct kernfs_node *kn);
/*
* symlink.c