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-rw-r--r--fs/configfs/configfs_internal.h15
-rw-r--r--fs/configfs/dir.c137
-rw-r--r--fs/configfs/file.c280
3 files changed, 257 insertions, 175 deletions
diff --git a/fs/configfs/configfs_internal.h b/fs/configfs/configfs_internal.h
index f752d83a9c44..520f1813e789 100644
--- a/fs/configfs/configfs_internal.h
+++ b/fs/configfs/configfs_internal.h
@@ -20,6 +20,15 @@
#include <linux/list.h>
#include <linux/spinlock.h>
+struct configfs_fragment {
+ atomic_t frag_count;
+ struct rw_semaphore frag_sem;
+ bool frag_dead;
+};
+
+void put_fragment(struct configfs_fragment *);
+struct configfs_fragment *get_fragment(struct configfs_fragment *);
+
struct configfs_dirent {
atomic_t s_count;
int s_dependent_count;
@@ -34,6 +43,7 @@ struct configfs_dirent {
#ifdef CONFIG_LOCKDEP
int s_depth;
#endif
+ struct configfs_fragment *s_frag;
};
#define CONFIGFS_ROOT 0x0001
@@ -61,8 +71,8 @@ extern int configfs_create(struct dentry *, umode_t mode, void (*init)(struct in
extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
extern int configfs_create_bin_file(struct config_item *,
const struct configfs_bin_attribute *);
-extern int configfs_make_dirent(struct configfs_dirent *,
- struct dentry *, void *, umode_t, int);
+extern int configfs_make_dirent(struct configfs_dirent *, struct dentry *,
+ void *, umode_t, int, struct configfs_fragment *);
extern int configfs_dirent_is_ready(struct configfs_dirent *);
extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
@@ -137,6 +147,7 @@ static inline void release_configfs_dirent(struct configfs_dirent * sd)
{
if (!(sd->s_type & CONFIGFS_ROOT)) {
kfree(sd->s_iattr);
+ put_fragment(sd->s_frag);
kmem_cache_free(configfs_dir_cachep, sd);
}
}
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 92112915de8e..79fc25aaa8cd 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -151,11 +151,38 @@ configfs_adjust_dir_dirent_depth_after_populate(struct configfs_dirent *sd)
#endif /* CONFIG_LOCKDEP */
+static struct configfs_fragment *new_fragment(void)
+{
+ struct configfs_fragment *p;
+
+ p = kmalloc(sizeof(struct configfs_fragment), GFP_KERNEL);
+ if (p) {
+ atomic_set(&p->frag_count, 1);
+ init_rwsem(&p->frag_sem);
+ p->frag_dead = false;
+ }
+ return p;
+}
+
+void put_fragment(struct configfs_fragment *frag)
+{
+ if (frag && atomic_dec_and_test(&frag->frag_count))
+ kfree(frag);
+}
+
+struct configfs_fragment *get_fragment(struct configfs_fragment *frag)
+{
+ if (likely(frag))
+ atomic_inc(&frag->frag_count);
+ return frag;
+}
+
/*
* Allocates a new configfs_dirent and links it to the parent configfs_dirent
*/
static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent *parent_sd,
- void *element, int type)
+ void *element, int type,
+ struct configfs_fragment *frag)
{
struct configfs_dirent * sd;
@@ -175,6 +202,7 @@ static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent *paren
kmem_cache_free(configfs_dir_cachep, sd);
return ERR_PTR(-ENOENT);
}
+ sd->s_frag = get_fragment(frag);
list_add(&sd->s_sibling, &parent_sd->s_children);
spin_unlock(&configfs_dirent_lock);
@@ -209,11 +237,11 @@ static int configfs_dirent_exists(struct configfs_dirent *parent_sd,
int configfs_make_dirent(struct configfs_dirent * parent_sd,
struct dentry * dentry, void * element,
- umode_t mode, int type)
+ umode_t mode, int type, struct configfs_fragment *frag)
{
struct configfs_dirent * sd;
- sd = configfs_new_dirent(parent_sd, element, type);
+ sd = configfs_new_dirent(parent_sd, element, type, frag);
if (IS_ERR(sd))
return PTR_ERR(sd);
@@ -260,7 +288,8 @@ static void init_symlink(struct inode * inode)
* until it is validated by configfs_dir_set_ready()
*/
-static int configfs_create_dir(struct config_item *item, struct dentry *dentry)
+static int configfs_create_dir(struct config_item *item, struct dentry *dentry,
+ struct configfs_fragment *frag)
{
int error;
umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
@@ -273,7 +302,8 @@ static int configfs_create_dir(struct config_item *item, struct dentry *dentry)
return error;
error = configfs_make_dirent(p->d_fsdata, dentry, item, mode,
- CONFIGFS_DIR | CONFIGFS_USET_CREATING);
+ CONFIGFS_DIR | CONFIGFS_USET_CREATING,
+ frag);
if (unlikely(error))
return error;
@@ -338,9 +368,10 @@ int configfs_create_link(struct configfs_symlink *sl,
{
int err = 0;
umode_t mode = S_IFLNK | S_IRWXUGO;
+ struct configfs_dirent *p = parent->d_fsdata;
- err = configfs_make_dirent(parent->d_fsdata, dentry, sl, mode,
- CONFIGFS_ITEM_LINK);
+ err = configfs_make_dirent(p, dentry, sl, mode,
+ CONFIGFS_ITEM_LINK, p->s_frag);
if (!err) {
err = configfs_create(dentry, mode, init_symlink);
if (err) {
@@ -599,7 +630,8 @@ static int populate_attrs(struct config_item *item)
static int configfs_attach_group(struct config_item *parent_item,
struct config_item *item,
- struct dentry *dentry);
+ struct dentry *dentry,
+ struct configfs_fragment *frag);
static void configfs_detach_group(struct config_item *item);
static void detach_groups(struct config_group *group)
@@ -647,7 +679,8 @@ static void detach_groups(struct config_group *group)
* try using vfs_mkdir. Just a thought.
*/
static int create_default_group(struct config_group *parent_group,
- struct config_group *group)
+ struct config_group *group,
+ struct configfs_fragment *frag)
{
int ret;
struct configfs_dirent *sd;
@@ -663,7 +696,7 @@ static int create_default_group(struct config_group *parent_group,
d_add(child, NULL);
ret = configfs_attach_group(&parent_group->cg_item,
- &group->cg_item, child);
+ &group->cg_item, child, frag);
if (!ret) {
sd = child->d_fsdata;
sd->s_type |= CONFIGFS_USET_DEFAULT;
@@ -677,13 +710,14 @@ static int create_default_group(struct config_group *parent_group,
return ret;
}
-static int populate_groups(struct config_group *group)
+static int populate_groups(struct config_group *group,
+ struct configfs_fragment *frag)
{
struct config_group *new_group;
int ret = 0;
list_for_each_entry(new_group, &group->default_groups, group_entry) {
- ret = create_default_group(group, new_group);
+ ret = create_default_group(group, new_group, frag);
if (ret) {
detach_groups(group);
break;
@@ -797,11 +831,12 @@ static void link_group(struct config_group *parent_group, struct config_group *g
*/
static int configfs_attach_item(struct config_item *parent_item,
struct config_item *item,
- struct dentry *dentry)
+ struct dentry *dentry,
+ struct configfs_fragment *frag)
{
int ret;
- ret = configfs_create_dir(item, dentry);
+ ret = configfs_create_dir(item, dentry, frag);
if (!ret) {
ret = populate_attrs(item);
if (ret) {
@@ -831,12 +866,13 @@ static void configfs_detach_item(struct config_item *item)
static int configfs_attach_group(struct config_item *parent_item,
struct config_item *item,
- struct dentry *dentry)
+ struct dentry *dentry,
+ struct configfs_fragment *frag)
{
int ret;
struct configfs_dirent *sd;
- ret = configfs_attach_item(parent_item, item, dentry);
+ ret = configfs_attach_item(parent_item, item, dentry, frag);
if (!ret) {
sd = dentry->d_fsdata;
sd->s_type |= CONFIGFS_USET_DIR;
@@ -852,7 +888,7 @@ static int configfs_attach_group(struct config_item *parent_item,
*/
inode_lock_nested(d_inode(dentry), I_MUTEX_CHILD);
configfs_adjust_dir_dirent_depth_before_populate(sd);
- ret = populate_groups(to_config_group(item));
+ ret = populate_groups(to_config_group(item), frag);
if (ret) {
configfs_detach_item(item);
d_inode(dentry)->i_flags |= S_DEAD;
@@ -1247,6 +1283,7 @@ static int configfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode
struct configfs_dirent *sd;
const struct config_item_type *type;
struct module *subsys_owner = NULL, *new_item_owner = NULL;
+ struct configfs_fragment *frag;
char *name;
sd = dentry->d_parent->d_fsdata;
@@ -1265,6 +1302,12 @@ static int configfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode
goto out;
}
+ frag = new_fragment();
+ if (!frag) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
/* Get a working ref for the duration of this function */
parent_item = configfs_get_config_item(dentry->d_parent);
type = parent_item->ci_type;
@@ -1367,9 +1410,9 @@ static int configfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode
spin_unlock(&configfs_dirent_lock);
if (group)
- ret = configfs_attach_group(parent_item, item, dentry);
+ ret = configfs_attach_group(parent_item, item, dentry, frag);
else
- ret = configfs_attach_item(parent_item, item, dentry);
+ ret = configfs_attach_item(parent_item, item, dentry, frag);
spin_lock(&configfs_dirent_lock);
sd->s_type &= ~CONFIGFS_USET_IN_MKDIR;
@@ -1406,6 +1449,7 @@ out_put:
* reference.
*/
config_item_put(parent_item);
+ put_fragment(frag);
out:
return ret;
@@ -1417,6 +1461,7 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
struct config_item *item;
struct configfs_subsystem *subsys;
struct configfs_dirent *sd;
+ struct configfs_fragment *frag;
struct module *subsys_owner = NULL, *dead_item_owner = NULL;
int ret;
@@ -1474,6 +1519,16 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
}
} while (ret == -EAGAIN);
+ frag = sd->s_frag;
+ if (down_write_killable(&frag->frag_sem)) {
+ spin_lock(&configfs_dirent_lock);
+ configfs_detach_rollback(dentry);
+ spin_unlock(&configfs_dirent_lock);
+ return -EINTR;
+ }
+ frag->frag_dead = true;
+ up_write(&frag->frag_sem);
+
/* Get a working ref for the duration of this function */
item = configfs_get_config_item(dentry);
@@ -1574,7 +1629,7 @@ static int configfs_dir_open(struct inode *inode, struct file *file)
*/
err = -ENOENT;
if (configfs_dirent_is_ready(parent_sd)) {
- file->private_data = configfs_new_dirent(parent_sd, NULL, 0);
+ file->private_data = configfs_new_dirent(parent_sd, NULL, 0, NULL);
if (IS_ERR(file->private_data))
err = PTR_ERR(file->private_data);
else
@@ -1732,8 +1787,13 @@ int configfs_register_group(struct config_group *parent_group,
{
struct configfs_subsystem *subsys = parent_group->cg_subsys;
struct dentry *parent;
+ struct configfs_fragment *frag;
int ret;
+ frag = new_fragment();
+ if (!frag)
+ return -ENOMEM;
+
mutex_lock(&subsys->su_mutex);
link_group(parent_group, group);
mutex_unlock(&subsys->su_mutex);
@@ -1741,7 +1801,7 @@ int configfs_register_group(struct config_group *parent_group,
parent = parent_group->cg_item.ci_dentry;
inode_lock_nested(d_inode(parent), I_MUTEX_PARENT);
- ret = create_default_group(parent_group, group);
+ ret = create_default_group(parent_group, group, frag);
if (ret)
goto err_out;
@@ -1749,12 +1809,14 @@ int configfs_register_group(struct config_group *parent_group,
configfs_dir_set_ready(group->cg_item.ci_dentry->d_fsdata);
spin_unlock(&configfs_dirent_lock);
inode_unlock(d_inode(parent));
+ put_fragment(frag);
return 0;
err_out:
inode_unlock(d_inode(parent));
mutex_lock(&subsys->su_mutex);
unlink_group(group);
mutex_unlock(&subsys->su_mutex);
+ put_fragment(frag);
return ret;
}
EXPORT_SYMBOL(configfs_register_group);
@@ -1770,16 +1832,12 @@ void configfs_unregister_group(struct config_group *group)
struct configfs_subsystem *subsys = group->cg_subsys;
struct dentry *dentry = group->cg_item.ci_dentry;
struct dentry *parent = group->cg_item.ci_parent->ci_dentry;
+ struct configfs_dirent *sd = dentry->d_fsdata;
+ struct configfs_fragment *frag = sd->s_frag;
- mutex_lock(&subsys->su_mutex);
- if (!group->cg_item.ci_parent->ci_group) {
- /*
- * The parent has already been unlinked and detached
- * due to a rmdir.
- */
- goto unlink_group;
- }
- mutex_unlock(&subsys->su_mutex);
+ down_write(&frag->frag_sem);
+ frag->frag_dead = true;
+ up_write(&frag->frag_sem);
inode_lock_nested(d_inode(parent), I_MUTEX_PARENT);
spin_lock(&configfs_dirent_lock);
@@ -1796,7 +1854,6 @@ void configfs_unregister_group(struct config_group *group)
dput(dentry);
mutex_lock(&subsys->su_mutex);
-unlink_group:
unlink_group(group);
mutex_unlock(&subsys->su_mutex);
}
@@ -1853,10 +1910,17 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys)
struct dentry *dentry;
struct dentry *root;
struct configfs_dirent *sd;
+ struct configfs_fragment *frag;
+
+ frag = new_fragment();
+ if (!frag)
+ return -ENOMEM;
root = configfs_pin_fs();
- if (IS_ERR(root))
+ if (IS_ERR(root)) {
+ put_fragment(frag);
return PTR_ERR(root);
+ }
if (!group->cg_item.ci_name)
group->cg_item.ci_name = group->cg_item.ci_namebuf;
@@ -1872,7 +1936,7 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys)
d_add(dentry, NULL);
err = configfs_attach_group(sd->s_element, &group->cg_item,
- dentry);
+ dentry, frag);
if (err) {
BUG_ON(d_inode(dentry));
d_drop(dentry);
@@ -1890,6 +1954,7 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys)
unlink_group(group);
configfs_release_fs();
}
+ put_fragment(frag);
return err;
}
@@ -1899,12 +1964,18 @@ void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
struct config_group *group = &subsys->su_group;
struct dentry *dentry = group->cg_item.ci_dentry;
struct dentry *root = dentry->d_sb->s_root;
+ struct configfs_dirent *sd = dentry->d_fsdata;
+ struct configfs_fragment *frag = sd->s_frag;
if (dentry->d_parent != root) {
pr_err("Tried to unregister non-subsystem!\n");
return;
}
+ down_write(&frag->frag_sem);
+ frag->frag_dead = true;
+ up_write(&frag->frag_sem);
+
inode_lock_nested(d_inode(root),
I_MUTEX_PARENT);
inode_lock_nested(d_inode(dentry), I_MUTEX_CHILD);
diff --git a/fs/configfs/file.c b/fs/configfs/file.c
index 61e4db4390a1..fb65b706cc0d 100644
--- a/fs/configfs/file.c
+++ b/fs/configfs/file.c
@@ -39,40 +39,44 @@ struct configfs_buffer {
bool write_in_progress;
char *bin_buffer;
int bin_buffer_size;
+ int cb_max_size;
+ struct config_item *item;
+ struct module *owner;
+ union {
+ struct configfs_attribute *attr;
+ struct configfs_bin_attribute *bin_attr;
+ };
};
+static inline struct configfs_fragment *to_frag(struct file *file)
+{
+ struct configfs_dirent *sd = file->f_path.dentry->d_fsdata;
-/**
- * fill_read_buffer - allocate and fill buffer from item.
- * @dentry: dentry pointer.
- * @buffer: data buffer for file.
- *
- * Allocate @buffer->page, if it hasn't been already, then call the
- * config_item's show() method to fill the buffer with this attribute's
- * data.
- * This is called only once, on the file's first read.
- */
-static int fill_read_buffer(struct dentry * dentry, struct configfs_buffer * buffer)
+ return sd->s_frag;
+}
+
+static int fill_read_buffer(struct file *file, struct configfs_buffer *buffer)
{
- struct configfs_attribute * attr = to_attr(dentry);
- struct config_item * item = to_item(dentry->d_parent);
- int ret = 0;
- ssize_t count;
+ struct configfs_fragment *frag = to_frag(file);
+ ssize_t count = -ENOENT;
if (!buffer->page)
buffer->page = (char *) get_zeroed_page(GFP_KERNEL);
if (!buffer->page)
return -ENOMEM;
- count = attr->show(item, buffer->page);
-
- BUG_ON(count > (ssize_t)SIMPLE_ATTR_SIZE);
- if (count >= 0) {
- buffer->needs_read_fill = 0;
- buffer->count = count;
- } else
- ret = count;
- return ret;
+ down_read(&frag->frag_sem);
+ if (!frag->frag_dead)
+ count = buffer->attr->show(buffer->item, buffer->page);
+ up_read(&frag->frag_sem);
+
+ if (count < 0)
+ return count;
+ if (WARN_ON_ONCE(count > (ssize_t)SIMPLE_ATTR_SIZE))
+ return -EIO;
+ buffer->needs_read_fill = 0;
+ buffer->count = count;
+ return 0;
}
/**
@@ -97,12 +101,13 @@ static int fill_read_buffer(struct dentry * dentry, struct configfs_buffer * buf
static ssize_t
configfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
- struct configfs_buffer * buffer = file->private_data;
+ struct configfs_buffer *buffer = file->private_data;
ssize_t retval = 0;
mutex_lock(&buffer->mutex);
if (buffer->needs_read_fill) {
- if ((retval = fill_read_buffer(file->f_path.dentry,buffer)))
+ retval = fill_read_buffer(file, buffer);
+ if (retval)
goto out;
}
pr_debug("%s: count = %zd, ppos = %lld, buf = %s\n",
@@ -138,10 +143,8 @@ static ssize_t
configfs_read_bin_file(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
+ struct configfs_fragment *frag = to_frag(file);
struct configfs_buffer *buffer = file->private_data;
- struct dentry *dentry = file->f_path.dentry;
- struct config_item *item = to_item(dentry->d_parent);
- struct configfs_bin_attribute *bin_attr = to_bin_attr(dentry);
ssize_t retval = 0;
ssize_t len = min_t(size_t, count, PAGE_SIZE);
@@ -156,14 +159,19 @@ configfs_read_bin_file(struct file *file, char __user *buf,
if (buffer->needs_read_fill) {
/* perform first read with buf == NULL to get extent */
- len = bin_attr->read(item, NULL, 0);
+ down_read(&frag->frag_sem);
+ if (!frag->frag_dead)
+ len = buffer->bin_attr->read(buffer->item, NULL, 0);
+ else
+ len = -ENOENT;
+ up_read(&frag->frag_sem);
if (len <= 0) {
retval = len;
goto out;
}
/* do not exceed the maximum value */
- if (bin_attr->cb_max_size && len > bin_attr->cb_max_size) {
+ if (buffer->cb_max_size && len > buffer->cb_max_size) {
retval = -EFBIG;
goto out;
}
@@ -176,7 +184,13 @@ configfs_read_bin_file(struct file *file, char __user *buf,
buffer->bin_buffer_size = len;
/* perform second read to fill buffer */
- len = bin_attr->read(item, buffer->bin_buffer, len);
+ down_read(&frag->frag_sem);
+ if (!frag->frag_dead)
+ len = buffer->bin_attr->read(buffer->item,
+ buffer->bin_buffer, len);
+ else
+ len = -ENOENT;
+ up_read(&frag->frag_sem);
if (len < 0) {
retval = len;
vfree(buffer->bin_buffer);
@@ -226,25 +240,17 @@ fill_write_buffer(struct configfs_buffer * buffer, const char __user * buf, size
return error ? -EFAULT : count;
}
-
-/**
- * flush_write_buffer - push buffer to config_item.
- * @dentry: dentry to the attribute
- * @buffer: data buffer for file.
- * @count: number of bytes
- *
- * Get the correct pointers for the config_item and the attribute we're
- * dealing with, then call the store() method for the attribute,
- * passing the buffer that we acquired in fill_write_buffer().
- */
-
static int
-flush_write_buffer(struct dentry * dentry, struct configfs_buffer * buffer, size_t count)
+flush_write_buffer(struct file *file, struct configfs_buffer *buffer, size_t count)
{
- struct configfs_attribute * attr = to_attr(dentry);
- struct config_item * item = to_item(dentry->d_parent);
-
- return attr->store(item, buffer->page, count);
+ struct configfs_fragment *frag = to_frag(file);
+ int res = -ENOENT;
+
+ down_read(&frag->frag_sem);
+ if (!frag->frag_dead)
+ res = buffer->attr->store(buffer->item, buffer->page, count);
+ up_read(&frag->frag_sem);
+ return res;
}
@@ -268,13 +274,13 @@ flush_write_buffer(struct dentry * dentry, struct configfs_buffer * buffer, size
static ssize_t
configfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
- struct configfs_buffer * buffer = file->private_data;
+ struct configfs_buffer *buffer = file->private_data;
ssize_t len;
mutex_lock(&buffer->mutex);
len = fill_write_buffer(buffer, buf, count);
if (len > 0)
- len = flush_write_buffer(file->f_path.dentry, buffer, len);
+ len = flush_write_buffer(file, buffer, len);
if (len > 0)
*ppos += len;
mutex_unlock(&buffer->mutex);
@@ -299,8 +305,6 @@ configfs_write_bin_file(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct configfs_buffer *buffer = file->private_data;
- struct dentry *dentry = file->f_path.dentry;
- struct configfs_bin_attribute *bin_attr = to_bin_attr(dentry);
void *tbuf = NULL;
ssize_t len;
@@ -316,8 +320,8 @@ configfs_write_bin_file(struct file *file, const char __user *buf,
/* buffer grows? */
if (*ppos + count > buffer->bin_buffer_size) {
- if (bin_attr->cb_max_size &&
- *ppos + count > bin_attr->cb_max_size) {
+ if (buffer->cb_max_size &&
+ *ppos + count > buffer->cb_max_size) {
len = -EFBIG;
goto out;
}
@@ -349,31 +353,51 @@ out:
return len;
}
-static int check_perm(struct inode * inode, struct file * file, int type)
+static int __configfs_open_file(struct inode *inode, struct file *file, int type)
{
- struct config_item *item = configfs_get_config_item(file->f_path.dentry->d_parent);
- struct configfs_attribute * attr = to_attr(file->f_path.dentry);
- struct configfs_bin_attribute *bin_attr = NULL;
- struct configfs_buffer * buffer;
- struct configfs_item_operations * ops = NULL;
- int error = 0;
+ struct dentry *dentry = file->f_path.dentry;
+ struct configfs_fragment *frag = to_frag(file);
+ struct configfs_attribute *attr;
+ struct configfs_buffer *buffer;
+ int error;
- if (!item || !attr)
- goto Einval;
+ error = -ENOMEM;
+ buffer = kzalloc(sizeof(struct configfs_buffer), GFP_KERNEL);
+ if (!buffer)
+ goto out;
- if (type & CONFIGFS_ITEM_BIN_ATTR)
- bin_attr = to_bin_attr(file->f_path.dentry);
+ error = -ENOENT;
+ down_read(&frag->frag_sem);
+ if (unlikely(frag->frag_dead))
+ goto out_free_buffer;
- /* Grab the module reference for this attribute if we have one */
- if (!try_module_get(attr->ca_owner)) {
- error = -ENODEV;
- goto Done;
+ error = -EINVAL;
+ buffer->item = to_item(dentry->d_parent);
+ if (!buffer->item)
+ goto out_free_buffer;
+
+ attr = to_attr(dentry);
+ if (!attr)
+ goto out_put_item;
+
+ if (type & CONFIGFS_ITEM_BIN_ATTR) {
+ buffer->bin_attr = to_bin_attr(dentry);
+ buffer->cb_max_size = buffer->bin_attr->cb_max_size;
+ } else {
+ buffer->attr = attr;
}
- if (item->ci_type)
- ops = item->ci_type->ct_item_ops;
- else
- goto Eaccess;
+ buffer->owner = attr->ca_owner;
+ /* Grab the module reference for this attribute if we have one */
+ error = -ENODEV;
+ if (!try_module_get(buffer->owner))
+ goto out_put_item;
+
+ error = -EACCES;
+ if (!buffer->item->ci_type)
+ goto out_put_module;
+
+ buffer->ops = buffer->item->ci_type->ct_item_ops;
/* File needs write support.
* The inode's perms must say it's ok,
@@ -381,13 +405,11 @@ static int check_perm(struct inode * inode, struct file * file, int type)
*/
if (file->f_mode & FMODE_WRITE) {
if (!(inode->i_mode & S_IWUGO))
- goto Eaccess;
-
+ goto out_put_module;
if ((type & CONFIGFS_ITEM_ATTR) && !attr->store)
- goto Eaccess;
-
- if ((type & CONFIGFS_ITEM_BIN_ATTR) && !bin_attr->write)
- goto Eaccess;
+ goto out_put_module;
+ if ((type & CONFIGFS_ITEM_BIN_ATTR) && !buffer->bin_attr->write)
+ goto out_put_module;
}
/* File needs read support.
@@ -396,92 +418,72 @@ static int check_perm(struct inode * inode, struct file * file, int type)
*/
if (file->f_mode & FMODE_READ) {
if (!(inode->i_mode & S_IRUGO))
- goto Eaccess;
-
+ goto out_put_module;
if ((type & CONFIGFS_ITEM_ATTR) && !attr->show)
- goto Eaccess;
-
- if ((type & CONFIGFS_ITEM_BIN_ATTR) && !bin_attr->read)
- goto Eaccess;
+ goto out_put_module;
+ if ((type & CONFIGFS_ITEM_BIN_ATTR) && !buffer->bin_attr->read)
+ goto out_put_module;
}
- /* No error? Great, allocate a buffer for the file, and store it
- * it in file->private_data for easy access.
- */
- buffer = kzalloc(sizeof(struct configfs_buffer),GFP_KERNEL);
- if (!buffer) {
- error = -ENOMEM;
- goto Enomem;
- }
mutex_init(&buffer->mutex);
buffer->needs_read_fill = 1;
buffer->read_in_progress = false;
buffer->write_in_progress = false;
- buffer->ops = ops;
file->private_data = buffer;
- goto Done;
+ up_read(&frag->frag_sem);
+ return 0;
- Einval:
- error = -EINVAL;
- goto Done;
- Eaccess:
- error = -EACCES;
- Enomem:
- module_put(attr->ca_owner);
- Done:
- if (error && item)
- config_item_put(item);
+out_put_module:
+ module_put(buffer->owner);
+out_put_item:
+ config_item_put(buffer->item);
+out_free_buffer:
+ up_read(&frag->frag_sem);
+ kfree(buffer);
+out:
return error;
}
static int configfs_release(struct inode *inode, struct file *filp)
{
- struct config_item * item = to_item(filp->f_path.dentry->d_parent);
- struct configfs_attribute * attr = to_attr(filp->f_path.dentry);
- struct module * owner = attr->ca_owner;
- struct configfs_buffer * buffer = filp->private_data;
-
- if (item)
- config_item_put(item);
- /* After this point, attr should not be accessed. */
- module_put(owner);
-
- if (buffer) {
- if (buffer->page)
- free_page((unsigned long)buffer->page);
- mutex_destroy(&buffer->mutex);
- kfree(buffer);
- }
+ struct configfs_buffer *buffer = filp->private_data;
+
+ module_put(buffer->owner);
+ if (buffer->page)
+ free_page((unsigned long)buffer->page);
+ mutex_destroy(&buffer->mutex);
+ kfree(buffer);
return 0;
}
static int configfs_open_file(struct inode *inode, struct file *filp)
{
- return check_perm(inode, filp, CONFIGFS_ITEM_ATTR);
+ return __configfs_open_file(inode, filp, CONFIGFS_ITEM_ATTR);
}
static int configfs_open_bin_file(struct inode *inode, struct file *filp)
{
- return check_perm(inode, filp, CONFIGFS_ITEM_BIN_ATTR);
+ return __configfs_open_file(inode, filp, CONFIGFS_ITEM_BIN_ATTR);
}
-static int configfs_release_bin_file(struct inode *inode, struct file *filp)
+static int configfs_release_bin_file(struct inode *inode, struct file *file)
{
- struct configfs_buffer *buffer = filp->private_data;
- struct dentry *dentry = filp->f_path.dentry;
- struct config_item *item = to_item(dentry->d_parent);
- struct configfs_bin_attribute *bin_attr = to_bin_attr(dentry);
- ssize_t len = 0;
- int ret;
+ struct configfs_buffer *buffer = file->private_data;
buffer->read_in_progress = false;
if (buffer->write_in_progress) {
+ struct configfs_fragment *frag = to_frag(file);
buffer->write_in_progress = false;
- len = bin_attr->write(item, buffer->bin_buffer,
- buffer->bin_buffer_size);
-
+ down_read(&frag->frag_sem);
+ if (!frag->frag_dead) {
+ /* result of ->release() is ignored */
+ buffer->bin_attr->write(buffer->item,
+ buffer->bin_buffer,
+ buffer->bin_buffer_size);
+ }
+ up_read(&frag->frag_sem);
/* vfree on NULL is safe */
vfree(buffer->bin_buffer);
buffer->bin_buffer = NULL;
@@ -489,10 +491,8 @@ static int configfs_release_bin_file(struct inode *inode, struct file *filp)
buffer->needs_read_fill = 1;
}
- ret = configfs_release(inode, filp);
- if (len < 0)
- return len;
- return ret;
+ configfs_release(inode, file);
+ return 0;
}
@@ -527,7 +527,7 @@ int configfs_create_file(struct config_item * item, const struct configfs_attrib
inode_lock_nested(d_inode(dir), I_MUTEX_NORMAL);
error = configfs_make_dirent(parent_sd, NULL, (void *) attr, mode,
- CONFIGFS_ITEM_ATTR);
+ CONFIGFS_ITEM_ATTR, parent_sd->s_frag);
inode_unlock(d_inode(dir));
return error;
@@ -549,7 +549,7 @@ int configfs_create_bin_file(struct config_item *item,
inode_lock_nested(dir->d_inode, I_MUTEX_NORMAL);
error = configfs_make_dirent(parent_sd, NULL, (void *) bin_attr, mode,
- CONFIGFS_ITEM_BIN_ATTR);
+ CONFIGFS_ITEM_BIN_ATTR, parent_sd->s_frag);
inode_unlock(dir->d_inode);
return error;
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-22 22:23:40 +0000