kernfs: update sysfs_init_inode_attrs()

sysfs_init_inode_attrs() is a bit clumsy to use requiring the caller
to check whether @sd->s_iattr is already set or not.  Rename it to
sysfs_inode_attrs(), update it to check whether @sd->s_iattr is
already initialized before trying to initialize it and return
@sd->s_iattr.  This simplifies the callers.

While at it,

* Rename struct sysfs_inode_attrs pointer variables to "attrs".  As
  kernfs no longer deals with "struct attribute", this isn't confusing
  and makes it easier to distinguish from struct iattr pointers.

* A new field will be added to sysfs_inode_attrs.  Reindent in
  preparation.

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>

2 files changed, 29 insertions, 37 deletions

diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index b4cae6fd717b..a1f83825afca 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -43,15 +43,17 @@ void __init sysfs_inode_init(void)
                 panic("failed to init sysfs_backing_dev_info");
 }
 
-static struct sysfs_inode_attrs *sysfs_init_inode_attrs(struct sysfs_dirent *sd)
+static struct sysfs_inode_attrs *sysfs_inode_attrs(struct sysfs_dirent *sd)
 {
-        struct sysfs_inode_attrs *attrs;
         struct iattr *iattrs;
 
-        attrs = kzalloc(sizeof(struct sysfs_inode_attrs), GFP_KERNEL);
-        if (!attrs)
+        if (sd->s_iattr)
+                return sd->s_iattr;
+
+        sd->s_iattr = kzalloc(sizeof(struct sysfs_inode_attrs), GFP_KERNEL);
+        if (!sd->s_iattr)
                 return NULL;
-        iattrs = &attrs->ia_iattr;
+        iattrs = &sd->s_iattr->ia_iattr;
 
         /* assign default attributes */
         iattrs->ia_mode = sd->s_mode;
@@ -59,26 +61,20 @@ static struct sysfs_inode_attrs *sysfs_init_inode_attrs(struct sysfs_dirent *sd)
         iattrs->ia_gid = GLOBAL_ROOT_GID;
         iattrs->ia_atime = iattrs->ia_mtime = iattrs->ia_ctime = CURRENT_TIME;
 
-        return attrs;
+        return sd->s_iattr;
 }
 
 static int __kernfs_setattr(struct sysfs_dirent *sd, const struct iattr *iattr)
 {
-        struct sysfs_inode_attrs *sd_attrs;
+        struct sysfs_inode_attrs *attrs;
         struct iattr *iattrs;
         unsigned int ia_valid = iattr->ia_valid;
 
-        sd_attrs = sd->s_iattr;
+        attrs = sysfs_inode_attrs(sd);
+        if (!attrs)
+                return -ENOMEM;
 
-        if (!sd_attrs) {
-                /* setting attributes for the first time, allocate now */
-                sd_attrs = sysfs_init_inode_attrs(sd);
-                if (!sd_attrs)
-                        return -ENOMEM;
-                sd->s_iattr = sd_attrs;
-        }
-        /* attributes were changed at least once in past */
-        iattrs = &sd_attrs->ia_iattr;
+        iattrs = &attrs->ia_iattr;
 
         if (ia_valid & ATTR_UID)
                 iattrs->ia_uid = iattr->ia_uid;
@@ -143,22 +139,19 @@ out:
 static int sysfs_sd_setsecdata(struct sysfs_dirent *sd, void **secdata,
                                u32 *secdata_len)
 {
-        struct sysfs_inode_attrs *iattrs;
+        struct sysfs_inode_attrs *attrs;
         void *old_secdata;
         size_t old_secdata_len;
 
-        if (!sd->s_iattr) {
-                sd->s_iattr = sysfs_init_inode_attrs(sd);
-                if (!sd->s_iattr)
-                        return -ENOMEM;
-        }
+        attrs = sysfs_inode_attrs(sd);
+        if (!attrs)
+                return -ENOMEM;
 
-        iattrs = sd->s_iattr;
-        old_secdata = iattrs->ia_secdata;
-        old_secdata_len = iattrs->ia_secdata_len;
+        old_secdata = attrs->ia_secdata;
+        old_secdata_len = attrs->ia_secdata_len;
 
-        iattrs->ia_secdata = *secdata;
-        iattrs->ia_secdata_len = *secdata_len;
+        attrs->ia_secdata = *secdata;
+        attrs->ia_secdata_len = *secdata_len;
 
         *secdata = old_secdata;
         *secdata_len = old_secdata_len;
@@ -216,17 +209,16 @@ static inline void set_inode_attr(struct inode *inode, struct iattr *iattr)
 
 static void sysfs_refresh_inode(struct sysfs_dirent *sd, struct inode *inode)
 {
-        struct sysfs_inode_attrs *iattrs = sd->s_iattr;
+        struct sysfs_inode_attrs *attrs = sd->s_iattr;
 
         inode->i_mode = sd->s_mode;
-        if (iattrs) {
+        if (attrs) {
                 /* sysfs_dirent has non-default attributes
                  * get them from persistent copy in sysfs_dirent
                  */
-                set_inode_attr(inode, &iattrs->ia_iattr);
-                security_inode_notifysecctx(inode,
-                                            iattrs->ia_secdata,
-                                            iattrs->ia_secdata_len);
+                set_inode_attr(inode, &attrs->ia_iattr);
+                security_inode_notifysecctx(inode, attrs->ia_secdata,
+                                            attrs->ia_secdata_len);
         }
 
         if (sysfs_type(sd) == SYSFS_DIR)
diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index d1ff591c5cf3..f25b3548bcca 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -18,9 +18,9 @@
 #include <linux/kernfs.h>
 
 struct sysfs_inode_attrs {
-        struct iattr    ia_iattr;
-        void            *ia_secdata;
-        u32             ia_secdata_len;
+        struct iattr            ia_iattr;
+        void                    *ia_secdata;
+        u32                     ia_secdata_len;
 };
 
 #define SD_DEACTIVATED_BIAS             INT_MIN