#include <linux/pagemap.h>
#include <linux/mount.h>
#include <linux/vfs.h>
+#include <linux/mutex.h>
+
#include <asm/uaccess.h>
int simple_getattr(struct vfsmount *mnt, struct dentry *dentry,
}
/*
- * Lookup the data. This is trivial - if the dentry didn't already
- * exist, we know it is negative.
+ * Retaining negative dentries for an in-memory filesystem just wastes
+ * memory and lookup time: arrange for them to be deleted immediately.
*/
+static int simple_delete_dentry(struct dentry *dentry)
+{
+ return 1;
+}
+/*
+ * Lookup the data. This is trivial - if the dentry didn't already
+ * exist, we know it is negative. Set d_op to delete negative dentries.
+ */
struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
+ static struct dentry_operations simple_dentry_operations = {
+ .d_delete = simple_delete_dentry,
+ };
+
if (dentry->d_name.len > NAME_MAX)
return ERR_PTR(-ENAMETOOLONG);
+ dentry->d_op = &simple_dentry_operations;
d_add(dentry, NULL);
return NULL;
}
loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin)
{
- down(&file->f_dentry->d_inode->i_sem);
+ mutex_lock(&file->f_dentry->d_inode->i_mutex);
switch (origin) {
case 1:
offset += file->f_pos;
if (offset >= 0)
break;
default:
- up(&file->f_dentry->d_inode->i_sem);
+ mutex_unlock(&file->f_dentry->d_inode->i_mutex);
return -EINVAL;
}
if (offset != file->f_pos) {
loff_t n = file->f_pos - 2;
spin_lock(&dcache_lock);
- list_del(&cursor->d_child);
+ list_del(&cursor->d_u.d_child);
p = file->f_dentry->d_subdirs.next;
while (n && p != &file->f_dentry->d_subdirs) {
struct dentry *next;
- next = list_entry(p, struct dentry, d_child);
+ next = list_entry(p, struct dentry, d_u.d_child);
if (!d_unhashed(next) && next->d_inode)
n--;
p = p->next;
}
- list_add_tail(&cursor->d_child, p);
+ list_add_tail(&cursor->d_u.d_child, p);
spin_unlock(&dcache_lock);
}
}
- up(&file->f_dentry->d_inode->i_sem);
+ mutex_unlock(&file->f_dentry->d_inode->i_mutex);
return offset;
}
* both impossible due to the lock on directory.
*/
-int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir)
+static inline int do_dcache_readdir_filter(struct file * filp,
+ void * dirent, filldir_t filldir, int (*filter)(struct dentry *dentry))
{
struct dentry *dentry = filp->f_dentry;
struct dentry *cursor = filp->private_data;
- struct list_head *p, *q = &cursor->d_child;
+ struct list_head *p, *q = &cursor->d_u.d_child;
ino_t ino;
int i = filp->f_pos;
}
for (p=q->next; p != &dentry->d_subdirs; p=p->next) {
struct dentry *next;
- next = list_entry(p, struct dentry, d_child);
+ next = list_entry(p, struct dentry, d_u.d_child);
if (d_unhashed(next) || !next->d_inode)
continue;
+ if (filter && !filter(next))
+ continue;
spin_unlock(&dcache_lock);
if (filldir(dirent, next->d_name.name, next->d_name.len, filp->f_pos, next->d_inode->i_ino, dt_type(next->d_inode)) < 0)
return 0;
}
+int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir)
+{
+ return do_dcache_readdir_filter(filp, dirent, filldir, NULL);
+}
+
+int dcache_readdir_filter(struct file * filp, void * dirent, filldir_t filldir,
+ int (*filter)(struct dentry *))
+{
+ return do_dcache_readdir_filter(filp, dirent, filldir, filter);
+}
+
+
ssize_t generic_read_dir(struct file *filp, char __user *buf, size_t siz, loff_t *ppos)
{
return -EISDIR;
}
-struct file_operations simple_dir_operations = {
+const struct file_operations simple_dir_operations = {
.open = dcache_dir_open,
.release = dcache_dir_close,
.llseek = dcache_dir_lseek,
.read = generic_read_dir,
.readdir = dcache_readdir,
+ .fsync = simple_sync_file,
};
struct inode_operations simple_dir_inode_operations = {
s->s_blocksize_bits = 10;
s->s_magic = magic;
s->s_op = ops ? ops : &default_ops;
+ s->s_time_gran = 1;
root = new_inode(s);
if (!root)
goto Enomem;
int ret = 0;
spin_lock(&dcache_lock);
- list_for_each_entry(child, &dentry->d_subdirs, d_child)
+ list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)
if (simple_positive(child))
goto out;
ret = 1;
/*
* No need to use i_size_read() here, the i_size
- * cannot change under us because we hold the i_sem.
+ * cannot change under us because we hold the i_mutex.
*/
if (pos > inode->i_size)
i_size_write(inode, pos);
s->s_blocksize_bits = PAGE_CACHE_SHIFT;
s->s_magic = magic;
s->s_op = &s_ops;
+ s->s_time_gran = 1;
inode = new_inode(s);
if (!inode)
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
inode->i_op = &simple_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
+ inode->i_nlink = 2;
root = d_alloc_root(inode);
if (!root) {
iput(inode);
return -ENOMEM;
}
for (i = 0; !files->name || files->name[0]; i++, files++) {
- struct qstr name;
if (!files->name)
continue;
- name.name = files->name;
- name.len = strlen(name.name);
- name.hash = full_name_hash(name.name, name.len);
- dentry = d_alloc(root, &name);
+ dentry = d_alloc_name(root, files->name);
if (!dentry)
goto out;
inode = new_inode(s);
return -ENOMEM;
}
-static spinlock_t pin_fs_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(pin_fs_lock);
int simple_pin_fs(char *name, struct vfsmount **mount, int *count)
{
return count;
}
+/*
+ * Transaction based IO.
+ * The file expects a single write which triggers the transaction, and then
+ * possibly a read which collects the result - which is stored in a
+ * file-local buffer.
+ */
+char *simple_transaction_get(struct file *file, const char __user *buf, size_t size)
+{
+ struct simple_transaction_argresp *ar;
+ static DEFINE_SPINLOCK(simple_transaction_lock);
+
+ if (size > SIMPLE_TRANSACTION_LIMIT - 1)
+ return ERR_PTR(-EFBIG);
+
+ ar = (struct simple_transaction_argresp *)get_zeroed_page(GFP_KERNEL);
+ if (!ar)
+ return ERR_PTR(-ENOMEM);
+
+ spin_lock(&simple_transaction_lock);
+
+ /* only one write allowed per open */
+ if (file->private_data) {
+ spin_unlock(&simple_transaction_lock);
+ free_page((unsigned long)ar);
+ return ERR_PTR(-EBUSY);
+ }
+
+ file->private_data = ar;
+
+ spin_unlock(&simple_transaction_lock);
+
+ if (copy_from_user(ar->data, buf, size))
+ return ERR_PTR(-EFAULT);
+
+ return ar->data;
+}
+
+ssize_t simple_transaction_read(struct file *file, char __user *buf, size_t size, loff_t *pos)
+{
+ struct simple_transaction_argresp *ar = file->private_data;
+
+ if (!ar)
+ return 0;
+ return simple_read_from_buffer(buf, size, pos, ar->data, ar->size);
+}
+
+int simple_transaction_release(struct inode *inode, struct file *file)
+{
+ free_page((unsigned long)file->private_data);
+ return 0;
+}
+
+/* Simple attribute files */
+
+struct simple_attr {
+ u64 (*get)(void *);
+ void (*set)(void *, u64);
+ char get_buf[24]; /* enough to store a u64 and "\n\0" */
+ char set_buf[24];
+ void *data;
+ const char *fmt; /* format for read operation */
+ struct mutex mutex; /* protects access to these buffers */
+};
+
+/* simple_attr_open is called by an actual attribute open file operation
+ * to set the attribute specific access operations. */
+int simple_attr_open(struct inode *inode, struct file *file,
+ u64 (*get)(void *), void (*set)(void *, u64),
+ const char *fmt)
+{
+ struct simple_attr *attr;
+
+ attr = kmalloc(sizeof(*attr), GFP_KERNEL);
+ if (!attr)
+ return -ENOMEM;
+
+ attr->get = get;
+ attr->set = set;
+ attr->data = inode->u.generic_ip;
+ attr->fmt = fmt;
+ mutex_init(&attr->mutex);
+
+ file->private_data = attr;
+
+ return nonseekable_open(inode, file);
+}
+
+int simple_attr_close(struct inode *inode, struct file *file)
+{
+ kfree(file->private_data);
+ return 0;
+}
+
+/* read from the buffer that is filled with the get function */
+ssize_t simple_attr_read(struct file *file, char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ struct simple_attr *attr;
+ size_t size;
+ ssize_t ret;
+
+ attr = file->private_data;
+
+ if (!attr->get)
+ return -EACCES;
+
+ mutex_lock(&attr->mutex);
+ if (*ppos) /* continued read */
+ size = strlen(attr->get_buf);
+ else /* first read */
+ size = scnprintf(attr->get_buf, sizeof(attr->get_buf),
+ attr->fmt,
+ (unsigned long long)attr->get(attr->data));
+
+ ret = simple_read_from_buffer(buf, len, ppos, attr->get_buf, size);
+ mutex_unlock(&attr->mutex);
+ return ret;
+}
+
+/* interpret the buffer as a number to call the set function with */
+ssize_t simple_attr_write(struct file *file, const char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ struct simple_attr *attr;
+ u64 val;
+ size_t size;
+ ssize_t ret;
+
+ attr = file->private_data;
+
+ if (!attr->set)
+ return -EACCES;
+
+ mutex_lock(&attr->mutex);
+ ret = -EFAULT;
+ size = min(sizeof(attr->set_buf) - 1, len);
+ if (copy_from_user(attr->set_buf, buf, size))
+ goto out;
+
+ ret = len; /* claim we got the whole input */
+ attr->set_buf[size] = '\0';
+ val = simple_strtol(attr->set_buf, NULL, 0);
+ attr->set(attr->data, val);
+out:
+ mutex_unlock(&attr->mutex);
+ return ret;
+}
+
EXPORT_SYMBOL(dcache_dir_close);
EXPORT_SYMBOL(dcache_dir_lseek);
EXPORT_SYMBOL(dcache_dir_open);
EXPORT_SYMBOL(dcache_readdir);
+EXPORT_SYMBOL(dcache_readdir_filter);
EXPORT_SYMBOL(generic_read_dir);
+EXPORT_SYMBOL(get_sb_pseudo);
EXPORT_SYMBOL(simple_commit_write);
EXPORT_SYMBOL(simple_dir_inode_operations);
EXPORT_SYMBOL(simple_dir_operations);
EXPORT_SYMBOL(simple_empty);
+EXPORT_SYMBOL(d_alloc_name);
EXPORT_SYMBOL(simple_fill_super);
EXPORT_SYMBOL(simple_getattr);
EXPORT_SYMBOL(simple_link);
EXPORT_SYMBOL(simple_sync_file);
EXPORT_SYMBOL(simple_unlink);
EXPORT_SYMBOL(simple_read_from_buffer);
+EXPORT_SYMBOL(simple_transaction_get);
+EXPORT_SYMBOL(simple_transaction_read);
+EXPORT_SYMBOL(simple_transaction_release);
+EXPORT_SYMBOL_GPL(simple_attr_open);
+EXPORT_SYMBOL_GPL(simple_attr_close);
+EXPORT_SYMBOL_GPL(simple_attr_read);
+EXPORT_SYMBOL_GPL(simple_attr_write);
git://git.onelab.eu / linux-2.6.git / blobdiff