[PATCH 1/2] kernfs: update sysfs_init_inode_attrs()

Tejun Heo
2013-11-23T22:40:54Z

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>
---
fs/kernfs/inode.c | 60 ++++++++++++++++++++-------------------------
fs/kernfs/kernfs-internal.h | 6 ++---
2 files changed, 29 insertions(+), 37 deletions(-)

diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index b4cae6f..a1f8382 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 d1ff591..f25b354 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
--
1.8.4.2