sysfs, kernfs: prepare mmap path for kernfs

We're in the process of separating out core sysfs functionality into
kernfs which will deal with sysfs_dirents directly.  This patch
rearranges mmap path so that the kernfs and sysfs parts are separate.

sysfs_kf_bin_mmap() which handles the interaction with bin_attribute
mmap method is factored out of sysfs_bin_mmap(), which is renamed to
kernfs_file_mmap().  All vma ops are renamed accordingly.

sysfs_bin_mmap() is updated such that it can be used for both file
types.  This will eventually allow using the same file_operations for
both file types, which is necessary to separate out kernfs.

This patch doesn't introduce any behavior changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 39 insertions, 30 deletions

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 2f849e82c0eb..2e24e89bd92b 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -361,7 +361,19 @@ out_free:
         return len;
 }
 
-static void sysfs_bin_vma_open(struct vm_area_struct *vma)
+static int sysfs_kf_bin_mmap(struct sysfs_open_file *of,
+                             struct vm_area_struct *vma)
+{
+        struct bin_attribute *battr = of->sd->priv;
+        struct kobject *kobj = of->sd->s_parent->priv;
+
+        if (!battr->mmap)
+                return -ENODEV;
+
+        return battr->mmap(of->file, kobj, battr, vma);
+}
+
+static void kernfs_vma_open(struct vm_area_struct *vma)
 {
         struct file *file = vma->vm_file;
         struct sysfs_open_file *of = sysfs_of(file);
@@ -378,7 +390,7 @@ static void sysfs_bin_vma_open(struct vm_area_struct *vma)
         sysfs_put_active(of->sd);
 }
 
-static int sysfs_bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+static int kernfs_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
         struct file *file = vma->vm_file;
         struct sysfs_open_file *of = sysfs_of(file);
@@ -398,8 +410,8 @@ static int sysfs_bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
         return ret;
 }
 
-static int sysfs_bin_page_mkwrite(struct vm_area_struct *vma,
-                                  struct vm_fault *vmf)
+static int kernfs_vma_page_mkwrite(struct vm_area_struct *vma,
+                                   struct vm_fault *vmf)
 {
         struct file *file = vma->vm_file;
         struct sysfs_open_file *of = sysfs_of(file);
@@ -421,8 +433,8 @@ static int sysfs_bin_page_mkwrite(struct vm_area_struct *vma,
         return ret;
 }
 
-static int sysfs_bin_access(struct vm_area_struct *vma, unsigned long addr,
-                            void *buf, int len, int write)
+static int kernfs_vma_access(struct vm_area_struct *vma, unsigned long addr,
+                             void *buf, int len, int write)
 {
         struct file *file = vma->vm_file;
         struct sysfs_open_file *of = sysfs_of(file);
@@ -443,8 +455,8 @@ static int sysfs_bin_access(struct vm_area_struct *vma, unsigned long addr,
 }
 
 #ifdef CONFIG_NUMA
-static int sysfs_bin_set_policy(struct vm_area_struct *vma,
-                                struct mempolicy *new)
+static int kernfs_vma_set_policy(struct vm_area_struct *vma,
+                                 struct mempolicy *new)
 {
         struct file *file = vma->vm_file;
         struct sysfs_open_file *of = sysfs_of(file);
@@ -464,8 +476,8 @@ static int sysfs_bin_set_policy(struct vm_area_struct *vma,
         return ret;
 }
 
-static struct mempolicy *sysfs_bin_get_policy(struct vm_area_struct *vma,
-                                              unsigned long addr)
+static struct mempolicy *kernfs_vma_get_policy(struct vm_area_struct *vma,
+                                               unsigned long addr)
 {
         struct file *file = vma->vm_file;
         struct sysfs_open_file *of = sysfs_of(file);
@@ -485,8 +497,9 @@ static struct mempolicy *sysfs_bin_get_policy(struct vm_area_struct *vma,
         return pol;
 }
 
-static int sysfs_bin_migrate(struct vm_area_struct *vma, const nodemask_t *from,
-                             const nodemask_t *to, unsigned long flags)
+static int kernfs_vma_migrate(struct vm_area_struct *vma,
+                              const nodemask_t *from, const nodemask_t *to,
+                              unsigned long flags)
 {
         struct file *file = vma->vm_file;
         struct sysfs_open_file *of = sysfs_of(file);
@@ -507,36 +520,31 @@ static int sysfs_bin_migrate(struct vm_area_struct *vma, const nodemask_t *from,
 }
 #endif
 
-static const struct vm_operations_struct sysfs_bin_vm_ops = {
-        .open           = sysfs_bin_vma_open,
-        .fault          = sysfs_bin_fault,
-        .page_mkwrite   = sysfs_bin_page_mkwrite,
-        .access         = sysfs_bin_access,
+static const struct vm_operations_struct kernfs_vm_ops = {
+        .open           = kernfs_vma_open,
+        .fault          = kernfs_vma_fault,
+        .page_mkwrite   = kernfs_vma_page_mkwrite,
+        .access         = kernfs_vma_access,
 #ifdef CONFIG_NUMA
-        .set_policy     = sysfs_bin_set_policy,
-        .get_policy     = sysfs_bin_get_policy,
-        .migrate        = sysfs_bin_migrate,
+        .set_policy     = kernfs_vma_set_policy,
+        .get_policy     = kernfs_vma_get_policy,
+        .migrate        = kernfs_vma_migrate,
 #endif
 };
 
-static int sysfs_bin_mmap(struct file *file, struct vm_area_struct *vma)
+static int kernfs_file_mmap(struct file *file, struct vm_area_struct *vma)
 {
         struct sysfs_open_file *of = sysfs_of(file);
-        struct bin_attribute *battr = of->sd->priv;
-        struct kobject *kobj = of->sd->s_parent->priv;
         int rc;
 
         mutex_lock(&of->mutex);
 
-        /* need of->sd for battr, its parent for kobj */
         rc = -ENODEV;
         if (!sysfs_get_active(of->sd))
                 goto out_unlock;
 
-        if (!battr->mmap)
-                goto out_put;
-
-        rc = battr->mmap(file, kobj, battr, vma);
+        if (sysfs_is_bin(of->sd))
+                rc = sysfs_kf_bin_mmap(of, vma);
         if (rc)
                 goto out_put;
 
@@ -563,7 +571,7 @@ static int sysfs_bin_mmap(struct file *file, struct vm_area_struct *vma)
         rc = 0;
         of->mmapped = 1;
         of->vm_ops = vma->vm_ops;
-        vma->vm_ops = &sysfs_bin_vm_ops;
+        vma->vm_ops = &kernfs_vm_ops;
 out_put:
         sysfs_put_active(of->sd);
 out_unlock:
@@ -877,6 +885,7 @@ const struct file_operations sysfs_file_operations = {
         .read           = kernfs_file_read,
         .write          = kernfs_file_write,
         .llseek         = generic_file_llseek,
+        .mmap           = kernfs_file_mmap,
         .open           = sysfs_open_file,
         .release        = sysfs_release,
         .poll           = sysfs_poll,
@@ -886,7 +895,7 @@ const struct file_operations sysfs_bin_operations = {
         .read           = kernfs_file_read,
         .write          = kernfs_file_write,
         .llseek         = generic_file_llseek,
-        .mmap           = sysfs_bin_mmap,
+        .mmap           = kernfs_file_mmap,
         .open           = sysfs_open_file,
         .release        = sysfs_release,
         .poll           = sysfs_poll,