sysfs: Remove sysfs_get/put_active_two
It turns out that holding an active reference on a directory is
pointless. The purpose of the active references are to allows us to
block when removing sysfs entries that have custom methods so we don't
remove modules while running modular code and to keep those custom
methods from accessing data structures after the files have been
removed. Further sysfs_remove_dir remove all elements in the
directory before removing the directory itself, so there is no chance
we will remove a directory with active children.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c
index a0a500a..e9d2935 100644
--- a/fs/sysfs/bin.c
+++ b/fs/sysfs/bin.c
@@ -54,14 +54,14 @@
int rc;
/* need attr_sd for attr, its parent for kobj */
- if (!sysfs_get_active_two(attr_sd))
+ if (!sysfs_get_active(attr_sd))
return -ENODEV;
rc = -EIO;
if (attr->read)
rc = attr->read(kobj, attr, buffer, off, count);
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
return rc;
}
@@ -125,14 +125,14 @@
int rc;
/* need attr_sd for attr, its parent for kobj */
- if (!sysfs_get_active_two(attr_sd))
+ if (!sysfs_get_active(attr_sd))
return -ENODEV;
rc = -EIO;
if (attr->write)
rc = attr->write(kobj, attr, buffer, offset, count);
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
return rc;
}
@@ -184,12 +184,12 @@
if (!bb->vm_ops || !bb->vm_ops->open)
return;
- if (!sysfs_get_active_two(attr_sd))
+ if (!sysfs_get_active(attr_sd))
return;
bb->vm_ops->open(vma);
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
}
static void bin_vma_close(struct vm_area_struct *vma)
@@ -201,12 +201,12 @@
if (!bb->vm_ops || !bb->vm_ops->close)
return;
- if (!sysfs_get_active_two(attr_sd))
+ if (!sysfs_get_active(attr_sd))
return;
bb->vm_ops->close(vma);
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
}
static int bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
@@ -219,12 +219,12 @@
if (!bb->vm_ops || !bb->vm_ops->fault)
return VM_FAULT_SIGBUS;
- if (!sysfs_get_active_two(attr_sd))
+ if (!sysfs_get_active(attr_sd))
return VM_FAULT_SIGBUS;
ret = bb->vm_ops->fault(vma, vmf);
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
return ret;
}
@@ -241,12 +241,12 @@
if (!bb->vm_ops->page_mkwrite)
return 0;
- if (!sysfs_get_active_two(attr_sd))
+ if (!sysfs_get_active(attr_sd))
return VM_FAULT_SIGBUS;
ret = bb->vm_ops->page_mkwrite(vma, vmf);
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
return ret;
}
@@ -261,12 +261,12 @@
if (!bb->vm_ops || !bb->vm_ops->access)
return -EINVAL;
- if (!sysfs_get_active_two(attr_sd))
+ if (!sysfs_get_active(attr_sd))
return -EINVAL;
ret = bb->vm_ops->access(vma, addr, buf, len, write);
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
return ret;
}
@@ -281,12 +281,12 @@
if (!bb->vm_ops || !bb->vm_ops->set_policy)
return 0;
- if (!sysfs_get_active_two(attr_sd))
+ if (!sysfs_get_active(attr_sd))
return -EINVAL;
ret = bb->vm_ops->set_policy(vma, new);
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
return ret;
}
@@ -301,12 +301,12 @@
if (!bb->vm_ops || !bb->vm_ops->get_policy)
return vma->vm_policy;
- if (!sysfs_get_active_two(attr_sd))
+ if (!sysfs_get_active(attr_sd))
return vma->vm_policy;
pol = bb->vm_ops->get_policy(vma, addr);
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
return pol;
}
@@ -321,12 +321,12 @@
if (!bb->vm_ops || !bb->vm_ops->migrate)
return 0;
- if (!sysfs_get_active_two(attr_sd))
+ if (!sysfs_get_active(attr_sd))
return 0;
ret = bb->vm_ops->migrate(vma, from, to, flags);
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
return ret;
}
#endif
@@ -356,7 +356,7 @@
/* need attr_sd for attr, its parent for kobj */
rc = -ENODEV;
- if (!sysfs_get_active_two(attr_sd))
+ if (!sysfs_get_active(attr_sd))
goto out_unlock;
rc = -EINVAL;
@@ -384,7 +384,7 @@
bb->vm_ops = vma->vm_ops;
vma->vm_ops = &bin_vm_ops;
out_put:
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
out_unlock:
mutex_unlock(&bb->mutex);
@@ -399,7 +399,7 @@
int error;
/* binary file operations requires both @sd and its parent */
- if (!sysfs_get_active_two(attr_sd))
+ if (!sysfs_get_active(attr_sd))
return -ENODEV;
error = -EACCES;
@@ -426,11 +426,11 @@
mutex_unlock(&sysfs_bin_lock);
/* open succeeded, put active references */
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
return 0;
err_out:
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
kfree(bb);
return error;
}
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 5c4703d..1bdc42f 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -93,7 +93,7 @@
* RETURNS:
* Pointer to @sd on success, NULL on failure.
*/
-static struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
+struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
{
if (unlikely(!sd))
return NULL;
@@ -124,7 +124,7 @@
* Put an active reference to @sd. This function is noop if @sd
* is NULL.
*/
-static void sysfs_put_active(struct sysfs_dirent *sd)
+void sysfs_put_active(struct sysfs_dirent *sd)
{
struct completion *cmpl;
int v;
@@ -145,45 +145,6 @@
}
/**
- * sysfs_get_active_two - get active references to sysfs_dirent and parent
- * @sd: sysfs_dirent of interest
- *
- * Get active reference to @sd and its parent. Parent's active
- * reference is grabbed first. This function is noop if @sd is
- * NULL.
- *
- * RETURNS:
- * Pointer to @sd on success, NULL on failure.
- */
-struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd)
-{
- if (sd) {
- if (sd->s_parent && unlikely(!sysfs_get_active(sd->s_parent)))
- return NULL;
- if (unlikely(!sysfs_get_active(sd))) {
- sysfs_put_active(sd->s_parent);
- return NULL;
- }
- }
- return sd;
-}
-
-/**
- * sysfs_put_active_two - put active references to sysfs_dirent and parent
- * @sd: sysfs_dirent of interest
- *
- * Put active references to @sd and its parent. This function is
- * noop if @sd is NULL.
- */
-void sysfs_put_active_two(struct sysfs_dirent *sd)
-{
- if (sd) {
- sysfs_put_active(sd);
- sysfs_put_active(sd->s_parent);
- }
-}
-
-/**
* sysfs_deactivate - deactivate sysfs_dirent
* @sd: sysfs_dirent to deactivate
*
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index ced2299..4096136 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -85,13 +85,13 @@
return -ENOMEM;
/* need attr_sd for attr and ops, its parent for kobj */
- if (!sysfs_get_active_two(attr_sd))
+ if (!sysfs_get_active(attr_sd))
return -ENODEV;
buffer->event = atomic_read(&attr_sd->s_attr.open->event);
count = ops->show(kobj, attr_sd->s_attr.attr, buffer->page);
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
/*
* The code works fine with PAGE_SIZE return but it's likely to
@@ -203,12 +203,12 @@
int rc;
/* need attr_sd for attr and ops, its parent for kobj */
- if (!sysfs_get_active_two(attr_sd))
+ if (!sysfs_get_active(attr_sd))
return -ENODEV;
rc = ops->store(kobj, attr_sd->s_attr.attr, buffer->page, count);
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
return rc;
}
@@ -344,7 +344,7 @@
memmove(last_sysfs_file, p, strlen(p) + 1);
/* need attr_sd for attr and ops, its parent for kobj */
- if (!sysfs_get_active_two(attr_sd))
+ if (!sysfs_get_active(attr_sd))
return -ENODEV;
/* every kobject with an attribute needs a ktype assigned */
@@ -393,13 +393,13 @@
goto err_free;
/* open succeeded, put active references */
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
return 0;
err_free:
kfree(buffer);
err_out:
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
return error;
}
@@ -437,12 +437,12 @@
struct sysfs_open_dirent *od = attr_sd->s_attr.open;
/* need parent for the kobj, grab both */
- if (!sysfs_get_active_two(attr_sd))
+ if (!sysfs_get_active(attr_sd))
goto trigger;
poll_wait(filp, &od->poll, wait);
- sysfs_put_active_two(attr_sd);
+ sysfs_put_active(attr_sd);
if (buffer->event != atomic_read(&od->event))
goto trigger;
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index cdd9377..bb7723c 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -124,8 +124,8 @@
extern const struct inode_operations sysfs_dir_inode_operations;
struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);
-struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd);
-void sysfs_put_active_two(struct sysfs_dirent *sd);
+struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);
+void sysfs_put_active(struct sysfs_dirent *sd);
void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
struct sysfs_dirent *parent_sd);
int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);