sysfs: merge sysfs_elem_bin_attr into sysfs_elem_attr

3124eb1679 ("sysfs: merge regular and bin file handling") folded bin
file handling into regular file handling.  Among other things, bin
file now shares the same open path including sysfs_open_dirent
association using sysfs_dirent->s_attr.open.  This is buggy because
->s_bin_attr lives in the same union and doesn't have the field.  This
bug doesn't trigger because sysfs_elem_bin_attr doesn't have an active
field at the conflicting position.  It does have a field "buffers" but
it isn't used anymore.

This patch collapses sysfs_elem_bin_attr into sysfs_elem_attr so that
the bin_attr is accessed through ->s_attr.bin_attr which lives with
->s_attr.attr in an anonymous union.  The code paths already assume
bin_attr contains attr as the first element, so this doesn't add any
more assumptions while making it explicit that the two types are
handled together.

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

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index c379597..0d7368d 100644 (file)
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -154,7 +154,7 @@ static ssize_t sysfs_bin_read(struct file *file, char __user *userbuf,
                              size_t bytes, loff_t *off)
 {
        struct sysfs_open_file *of = sysfs_of(file);
-       struct bin_attribute *battr = of->sd->s_bin_attr.bin_attr;
+       struct bin_attribute *battr = of->sd->s_attr.bin_attr;
        struct kobject *kobj = of->sd->s_parent->s_dir.kobj;
        loff_t size = file_inode(file)->i_size;
        int count = min_t(size_t, bytes, PAGE_SIZE);
@@ -236,7 +236,7 @@ static int flush_write_buffer(struct sysfs_open_file *of, char *buf, loff_t off,
        }
 
        if (sysfs_is_bin(of->sd)) {
-               struct bin_attribute *battr = of->sd->s_bin_attr.bin_attr;
+               struct bin_attribute *battr = of->sd->s_attr.bin_attr;
 
                rc = -EIO;
                if (battr->write)
@@ -466,7 +466,7 @@ static const struct vm_operations_struct sysfs_bin_vm_ops = {
 static int sysfs_bin_mmap(struct file *file, struct vm_area_struct *vma)
 {
        struct sysfs_open_file *of = sysfs_of(file);
-       struct bin_attribute *battr = of->sd->s_bin_attr.bin_attr;
+       struct bin_attribute *battr = of->sd->s_attr.bin_attr;
        struct kobject *kobj = of->sd->s_parent->s_dir.kobj;
        int rc;
 
@@ -618,7 +618,7 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
                return -ENODEV;
 
        if (sysfs_is_bin(attr_sd)) {
-               struct bin_attribute *battr = attr_sd->s_bin_attr.bin_attr;
+               struct bin_attribute *battr = attr_sd->s_attr.bin_attr;
 
                has_read = battr->read || battr->mmap;
                has_write = battr->write || battr->mmap;

diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
index 2cb1b6b..825c556 100644 (file)
--- a/fs/sysfs/inode.c
+++ b/fs/sysfs/inode.c
@@ -258,7 +258,7 @@ static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode)
                inode->i_fop = &sysfs_file_operations;
                break;
        case SYSFS_KOBJ_BIN_ATTR:
-               bin_attr = sd->s_bin_attr.bin_attr;
+               bin_attr = sd->s_attr.bin_attr;
                inode->i_size = bin_attr->size;
                inode->i_fop = &sysfs_bin_operations;
                break;

diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 94ac8fa..c095d95 100644 (file)
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -29,15 +29,13 @@ struct sysfs_elem_symlink {
 };
 
 struct sysfs_elem_attr {
-       struct attribute        *attr;
+       union {
+               struct attribute        *attr;
+               struct bin_attribute    *bin_attr;
+       };
        struct sysfs_open_dirent *open;
 };
 
-struct sysfs_elem_bin_attr {
-       struct bin_attribute    *bin_attr;
-       struct hlist_head       buffers;
-};
-
 struct sysfs_inode_attrs {
        struct iattr    ia_iattr;
        void            *ia_secdata;
@@ -74,7 +72,6 @@ struct sysfs_dirent {
                struct sysfs_elem_dir           s_dir;
                struct sysfs_elem_symlink       s_symlink;
                struct sysfs_elem_attr          s_attr;
-               struct sysfs_elem_bin_attr      s_bin_attr;
        };
 
        unsigned short          s_flags;