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sysfs: reorganize sysfs_new_indoe() and sysfs_create()
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Reorganize/clean up sysfs_new_inode() and sysfs_create().

* sysfs_init_inode() is separated out from sysfs_new_inode() and is
  responsible for basic initialization.
* sysfs_instantiate() replaces the last step of sysfs_create() and is
  responsible for dentry instantitaion.
* type-specific initialization is moved out to the callers.
* mode is specified only once when creating a sysfs_dirent.
* spurious list_del_init(&sd->s_sibling) dropped from create_dir()

This change is to

* prepare for inode allocation fix.
* separate alloc and init code for synchronization update.
* make dentry/inode initialization more flexible for later changes.

This patch doesn't introduce visible behavior change.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Tejun Heo authored and Greg Kroah-Hartman committed Jul 11, 2007
1 parent 7f7cfff commit fc9f54b
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Showing 4 changed files with 118 additions and 144 deletions.
130 changes: 48 additions & 82 deletions fs/sysfs/dir.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -191,47 +191,26 @@ int sysfs_dirent_exist(struct sysfs_dirent *parent_sd,
return 0;
}

static int init_dir(struct inode * inode)
{
inode->i_op = &sysfs_dir_inode_operations;
inode->i_fop = &sysfs_dir_operations;

/* directory inodes start off with i_nlink == 2 (for "." entry) */
inc_nlink(inode);
return 0;
}

static int init_file(struct inode * inode)
{
inode->i_size = PAGE_SIZE;
inode->i_fop = &sysfs_file_operations;
return 0;
}

static int init_symlink(struct inode * inode)
{
inode->i_op = &sysfs_symlink_inode_operations;
return 0;
}

static int create_dir(struct kobject *kobj, struct dentry *parent,
const char *name, struct dentry **p_dentry)
{
int error;
umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
struct dentry *dentry;
struct inode *inode;
struct sysfs_dirent *sd;

mutex_lock(&parent->d_inode->i_mutex);

/* allocate */
dentry = lookup_one_len(name, parent, strlen(name));
if (IS_ERR(dentry)) {
error = PTR_ERR(dentry);
goto out_unlock;
}

error = -EEXIST;
if (sysfs_dirent_exist(parent->d_fsdata, name))
if (dentry->d_inode)
goto out_dput;

error = -ENOMEM;
Expand All @@ -240,19 +219,31 @@ static int create_dir(struct kobject *kobj, struct dentry *parent,
goto out_drop;
sd->s_elem.dir.kobj = kobj;

error = sysfs_create(sd, dentry, mode, init_dir);
if (error)
inode = sysfs_new_inode(sd);
if (!inode)
goto out_sput;

inode->i_op = &sysfs_dir_inode_operations;
inode->i_fop = &sysfs_dir_operations;
/* directory inodes start off with i_nlink == 2 (for "." entry) */
inc_nlink(inode);

/* link in */
error = -EEXIST;
if (sysfs_dirent_exist(parent->d_fsdata, name))
goto out_iput;

sysfs_instantiate(dentry, inode);
inc_nlink(parent->d_inode);
sysfs_attach_dirent(sd, parent->d_fsdata, dentry);

*p_dentry = dentry;
error = 0;
goto out_dput;
goto out_unlock; /* pin directory dentry in core */

out_iput:
iput(inode);
out_sput:
list_del_init(&sd->s_sibling);
sysfs_put(sd);
out_drop:
d_drop(dentry);
Expand Down Expand Up @@ -298,71 +289,46 @@ int sysfs_create_dir(struct kobject * kobj, struct dentry *shadow_parent)
return error;
}

/* attaches attribute's sysfs_dirent to the dentry corresponding to the
* attribute file
*/
static int sysfs_attach_attr(struct sysfs_dirent * sd, struct dentry * dentry)
{
struct attribute * attr = NULL;
struct bin_attribute * bin_attr = NULL;
int (* init) (struct inode *) = NULL;
int error = 0;

if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) {
bin_attr = sd->s_elem.bin_attr.bin_attr;
attr = &bin_attr->attr;
} else {
attr = sd->s_elem.attr.attr;
init = init_file;
}

error = sysfs_create(sd, dentry,
(attr->mode & S_IALLUGO) | S_IFREG, init);
if (error)
return error;

if (bin_attr) {
dentry->d_inode->i_size = bin_attr->size;
dentry->d_inode->i_fop = &bin_fops;
}

sysfs_attach_dentry(sd, dentry);

return 0;
}

static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry)
{
int err;

err = sysfs_create(sd, dentry, S_IFLNK|S_IRWXUGO, init_symlink);
if (!err)
sysfs_attach_dentry(sd, dentry);

return err;
}

static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
struct sysfs_dirent * sd;
int err = 0;
struct inode *inode;
int found = 0;

list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
if (sd->s_type & SYSFS_NOT_PINNED) {
if (strcmp(sd->s_name, dentry->d_name.name))
continue;

if (sd->s_type & SYSFS_KOBJ_LINK)
err = sysfs_attach_link(sd, dentry);
else
err = sysfs_attach_attr(sd, dentry);
if ((sd->s_type & SYSFS_NOT_PINNED) &&
!strcmp(sd->s_name, dentry->d_name.name)) {
found = 1;
break;
}
}

return ERR_PTR(err);
/* no such entry */
if (!found)
return NULL;

/* attach dentry and inode */
inode = sysfs_new_inode(sd);
if (!inode)
return ERR_PTR(-ENOMEM);

/* initialize inode according to type */
if (sd->s_type & SYSFS_KOBJ_ATTR) {
inode->i_size = PAGE_SIZE;
inode->i_fop = &sysfs_file_operations;
} else if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) {
struct bin_attribute *bin_attr = sd->s_elem.bin_attr.bin_attr;
inode->i_size = bin_attr->size;
inode->i_fop = &bin_fops;
} else if (sd->s_type & SYSFS_KOBJ_LINK)
inode->i_op = &sysfs_symlink_inode_operations;

sysfs_instantiate(dentry, inode);
sysfs_attach_dentry(sd, dentry);

return NULL;
}

const struct inode_operations sysfs_dir_inode_operations = {
Expand Down
108 changes: 57 additions & 51 deletions fs/sysfs/inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -133,62 +133,68 @@ static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
*/
static struct lock_class_key sysfs_inode_imutex_key;

struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent * sd)
void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode)
{
struct inode * inode = new_inode(sysfs_sb);
if (inode) {
inode->i_blocks = 0;
inode->i_mapping->a_ops = &sysfs_aops;
inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
inode->i_op = &sysfs_inode_operations;
inode->i_ino = sd->s_ino;
lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key);

if (sd->s_iattr) {
/* sysfs_dirent has non-default attributes
* get them for the new inode from persistent copy
* in sysfs_dirent
*/
set_inode_attr(inode, sd->s_iattr);
} else
set_default_inode_attr(inode, mode);
}
inode->i_blocks = 0;
inode->i_mapping->a_ops = &sysfs_aops;
inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
inode->i_op = &sysfs_inode_operations;
inode->i_ino = sd->s_ino;
lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key);

if (sd->s_iattr) {
/* sysfs_dirent has non-default attributes
* get them for the new inode from persistent copy
* in sysfs_dirent
*/
set_inode_attr(inode, sd->s_iattr);
} else
set_default_inode_attr(inode, sd->s_mode);
}

/**
* sysfs_new_inode - allocate new inode for sysfs_dirent
* @sd: sysfs_dirent to allocate inode for
*
* Allocate inode for @sd and initialize basics.
*
* LOCKING:
* Kernel thread context (may sleep).
*
* RETURNS:
* Pointer to allocated inode on success, NULL on failure.
*/
struct inode * sysfs_new_inode(struct sysfs_dirent *sd)
{
struct inode *inode;

inode = new_inode(sysfs_sb);
if (inode)
sysfs_init_inode(sd, inode);

return inode;
}

int sysfs_create(struct sysfs_dirent *sd, struct dentry *dentry, int mode,
int (*init)(struct inode *))
/**
* sysfs_instantiate - instantiate dentry
* @dentry: dentry to be instantiated
* @inode: inode associated with @sd
*
* Instantiate @dentry with @inode.
*
* LOCKING:
* None.
*/
void sysfs_instantiate(struct dentry *dentry, struct inode *inode)
{
int error = 0;
struct inode * inode = NULL;
if (dentry) {
if (!dentry->d_inode) {
if ((inode = sysfs_new_inode(mode, sd))) {
if (dentry->d_parent && dentry->d_parent->d_inode) {
struct inode *p_inode = dentry->d_parent->d_inode;
p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
}
goto Proceed;
}
else
error = -ENOMEM;
} else
error = -EEXIST;
} else
error = -ENOENT;
goto Done;

Proceed:
if (init)
error = init(inode);
if (!error) {
d_instantiate(dentry, inode);
if (S_ISDIR(mode))
dget(dentry); /* pin only directory dentry in core */
} else
iput(inode);
Done:
return error;
BUG_ON(!dentry || dentry->d_inode);

if (dentry->d_parent && dentry->d_parent->d_inode) {
struct inode *p_inode = dentry->d_parent->d_inode;
p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
}

d_instantiate(dentry, inode);
}

/**
Expand Down
18 changes: 10 additions & 8 deletions fs/sysfs/mount.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -29,6 +29,7 @@ static struct sysfs_dirent sysfs_root = {
.s_sibling = LIST_HEAD_INIT(sysfs_root.s_sibling),
.s_children = LIST_HEAD_INIT(sysfs_root.s_children),
.s_type = SYSFS_ROOT,
.s_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
.s_iattr = NULL,
.s_ino = 1,
};
Expand All @@ -45,18 +46,19 @@ static int sysfs_fill_super(struct super_block *sb, void *data, int silent)
sb->s_time_gran = 1;
sysfs_sb = sb;

inode = sysfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
&sysfs_root);
if (inode) {
inode->i_op = &sysfs_dir_inode_operations;
inode->i_fop = &sysfs_dir_operations;
/* directory inodes start off with i_nlink == 2 (for "." entry) */
inc_nlink(inode);
} else {
inode = new_inode(sysfs_sb);
if (!inode) {
pr_debug("sysfs: could not get root inode\n");
return -ENOMEM;
}

sysfs_init_inode(&sysfs_root, inode);

inode->i_op = &sysfs_dir_inode_operations;
inode->i_fop = &sysfs_dir_operations;
/* directory inodes start off with i_nlink == 2 (for "." entry) */
inc_nlink(inode);

root = d_alloc_root(inode);
if (!root) {
pr_debug("%s: could not get root dentry!\n",__FUNCTION__);
Expand Down
6 changes: 3 additions & 3 deletions fs/sysfs/sysfs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -57,9 +57,9 @@ extern struct vfsmount * sysfs_mount;
extern struct kmem_cache *sysfs_dir_cachep;

extern void sysfs_delete_inode(struct inode *inode);
extern struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent *);
extern int sysfs_create(struct sysfs_dirent *sd, struct dentry *dentry,
int mode, int (*init)(struct inode *));
extern void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode);
extern struct inode * sysfs_new_inode(struct sysfs_dirent *sd);
extern void sysfs_instantiate(struct dentry *dentry, struct inode *inode);

extern void release_sysfs_dirent(struct sysfs_dirent * sd);
extern int sysfs_dirent_exist(struct sysfs_dirent *, const unsigned char *);
Expand Down

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