* Library for filesystems writers.
*/
+#include <linux/blkdev.h>
#include <linux/export.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/vfs.h>
#include <linux/quotaops.h>
#include <linux/mutex.h>
+#include <linux/namei.h>
#include <linux/exportfs.h>
#include <linux/writeback.h>
#include <linux/buffer_head.h> /* sync_mapping_buffers */
#include "internal.h"
-static inline int simple_positive(struct dentry *dentry)
-{
- return dentry->d_inode && !d_unhashed(dentry);
-}
-
int simple_getattr(struct vfsmount *mnt, struct dentry *dentry,
struct kstat *stat)
{
- struct inode *inode = dentry->d_inode;
+ struct inode *inode = d_inode(dentry);
generic_fillattr(inode, stat);
stat->blocks = inode->i_mapping->nrpages << (PAGE_CACHE_SHIFT - 9);
return 0;
}
+EXPORT_SYMBOL(simple_getattr);
int simple_statfs(struct dentry *dentry, struct kstatfs *buf)
{
buf->f_namelen = NAME_MAX;
return 0;
}
+EXPORT_SYMBOL(simple_statfs);
/*
* 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(const struct dentry *dentry)
+int always_delete_dentry(const struct dentry *dentry)
{
return 1;
}
+EXPORT_SYMBOL(always_delete_dentry);
+
+const struct dentry_operations simple_dentry_operations = {
+ .d_delete = always_delete_dentry,
+};
+EXPORT_SYMBOL(simple_dentry_operations);
/*
* Lookup the data. This is trivial - if the dentry didn't already
*/
struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
- static const struct dentry_operations simple_dentry_operations = {
- .d_delete = simple_delete_dentry,
- };
-
if (dentry->d_name.len > NAME_MAX)
return ERR_PTR(-ENAMETOOLONG);
- d_set_d_op(dentry, &simple_dentry_operations);
+ if (!dentry->d_sb->s_d_op)
+ d_set_d_op(dentry, &simple_dentry_operations);
d_add(dentry, NULL);
return NULL;
}
+EXPORT_SYMBOL(simple_lookup);
int dcache_dir_open(struct inode *inode, struct file *file)
{
return file->private_data ? 0 : -ENOMEM;
}
+EXPORT_SYMBOL(dcache_dir_open);
int dcache_dir_close(struct inode *inode, struct file *file)
{
dput(file->private_data);
return 0;
}
+EXPORT_SYMBOL(dcache_dir_close);
loff_t dcache_dir_lseek(struct file *file, loff_t offset, int whence)
{
struct dentry *dentry = file->f_path.dentry;
- mutex_lock(&dentry->d_inode->i_mutex);
+ mutex_lock(&d_inode(dentry)->i_mutex);
switch (whence) {
case 1:
offset += file->f_pos;
if (offset >= 0)
break;
default:
- mutex_unlock(&dentry->d_inode->i_mutex);
+ mutex_unlock(&d_inode(dentry)->i_mutex);
return -EINVAL;
}
if (offset != file->f_pos) {
spin_lock(&dentry->d_lock);
/* d_lock not required for cursor */
- list_del(&cursor->d_u.d_child);
+ list_del(&cursor->d_child);
p = dentry->d_subdirs.next;
while (n && p != &dentry->d_subdirs) {
struct dentry *next;
- next = list_entry(p, struct dentry, d_u.d_child);
+ next = list_entry(p, struct dentry, d_child);
spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED);
if (simple_positive(next))
n--;
spin_unlock(&next->d_lock);
p = p->next;
}
- list_add_tail(&cursor->d_u.d_child, p);
+ list_add_tail(&cursor->d_child, p);
spin_unlock(&dentry->d_lock);
}
}
- mutex_unlock(&dentry->d_inode->i_mutex);
+ mutex_unlock(&d_inode(dentry)->i_mutex);
return offset;
}
+EXPORT_SYMBOL(dcache_dir_lseek);
/* Relationship between i_mode and the DT_xxx types */
static inline unsigned char dt_type(struct inode *inode)
* both impossible due to the lock on directory.
*/
-int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir)
+int dcache_readdir(struct file *file, struct dir_context *ctx)
{
- struct dentry *dentry = filp->f_path.dentry;
- struct dentry *cursor = filp->private_data;
- struct list_head *p, *q = &cursor->d_u.d_child;
- ino_t ino;
- int i = filp->f_pos;
-
- switch (i) {
- case 0:
- ino = dentry->d_inode->i_ino;
- if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
- break;
- filp->f_pos++;
- i++;
- /* fallthrough */
- case 1:
- ino = parent_ino(dentry);
- if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
- break;
- filp->f_pos++;
- i++;
- /* fallthrough */
- default:
- spin_lock(&dentry->d_lock);
- if (filp->f_pos == 2)
- list_move(q, &dentry->d_subdirs);
+ struct dentry *dentry = file->f_path.dentry;
+ struct dentry *cursor = file->private_data;
+ struct list_head *p, *q = &cursor->d_child;
- for (p=q->next; p != &dentry->d_subdirs; p=p->next) {
- struct dentry *next;
- next = list_entry(p, struct dentry, d_u.d_child);
- spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED);
- if (!simple_positive(next)) {
- spin_unlock(&next->d_lock);
- continue;
- }
+ if (!dir_emit_dots(file, ctx))
+ return 0;
+ spin_lock(&dentry->d_lock);
+ if (ctx->pos == 2)
+ list_move(q, &dentry->d_subdirs);
+
+ for (p = q->next; p != &dentry->d_subdirs; p = p->next) {
+ struct dentry *next = list_entry(p, struct dentry, d_child);
+ spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED);
+ if (!simple_positive(next)) {
+ spin_unlock(&next->d_lock);
+ continue;
+ }
- spin_unlock(&next->d_lock);
- spin_unlock(&dentry->d_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;
- spin_lock(&dentry->d_lock);
- spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED);
- /* next is still alive */
- list_move(q, p);
- spin_unlock(&next->d_lock);
- p = q;
- filp->f_pos++;
- }
- spin_unlock(&dentry->d_lock);
+ spin_unlock(&next->d_lock);
+ spin_unlock(&dentry->d_lock);
+ if (!dir_emit(ctx, next->d_name.name, next->d_name.len,
+ d_inode(next)->i_ino, dt_type(d_inode(next))))
+ return 0;
+ spin_lock(&dentry->d_lock);
+ spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED);
+ /* next is still alive */
+ list_move(q, p);
+ spin_unlock(&next->d_lock);
+ p = q;
+ ctx->pos++;
}
+ spin_unlock(&dentry->d_lock);
return 0;
}
+EXPORT_SYMBOL(dcache_readdir);
ssize_t generic_read_dir(struct file *filp, char __user *buf, size_t siz, loff_t *ppos)
{
return -EISDIR;
}
+EXPORT_SYMBOL(generic_read_dir);
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,
+ .iterate = dcache_readdir,
.fsync = noop_fsync,
};
+EXPORT_SYMBOL(simple_dir_operations);
const struct inode_operations simple_dir_inode_operations = {
.lookup = simple_lookup,
};
+EXPORT_SYMBOL(simple_dir_inode_operations);
static const struct super_operations simple_super_operations = {
.statfs = simple_statfs,
deactivate_locked_super(s);
return ERR_PTR(-ENOMEM);
}
+EXPORT_SYMBOL(mount_pseudo);
int simple_open(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return 0;
}
+EXPORT_SYMBOL(simple_open);
int simple_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
{
- struct inode *inode = old_dentry->d_inode;
+ struct inode *inode = d_inode(old_dentry);
inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
inc_nlink(inode);
d_instantiate(dentry, inode);
return 0;
}
+EXPORT_SYMBOL(simple_link);
int simple_empty(struct dentry *dentry)
{
int ret = 0;
spin_lock(&dentry->d_lock);
- list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child) {
+ list_for_each_entry(child, &dentry->d_subdirs, d_child) {
spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED);
if (simple_positive(child)) {
spin_unlock(&child->d_lock);
spin_unlock(&dentry->d_lock);
return ret;
}
+EXPORT_SYMBOL(simple_empty);
int simple_unlink(struct inode *dir, struct dentry *dentry)
{
- struct inode *inode = dentry->d_inode;
+ struct inode *inode = d_inode(dentry);
inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
drop_nlink(inode);
dput(dentry);
return 0;
}
+EXPORT_SYMBOL(simple_unlink);
int simple_rmdir(struct inode *dir, struct dentry *dentry)
{
if (!simple_empty(dentry))
return -ENOTEMPTY;
- drop_nlink(dentry->d_inode);
+ drop_nlink(d_inode(dentry));
simple_unlink(dir, dentry);
drop_nlink(dir);
return 0;
}
+EXPORT_SYMBOL(simple_rmdir);
int simple_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
- struct inode *inode = old_dentry->d_inode;
- int they_are_dirs = S_ISDIR(old_dentry->d_inode->i_mode);
+ struct inode *inode = d_inode(old_dentry);
+ int they_are_dirs = d_is_dir(old_dentry);
if (!simple_empty(new_dentry))
return -ENOTEMPTY;
- if (new_dentry->d_inode) {
+ if (d_really_is_positive(new_dentry)) {
simple_unlink(new_dir, new_dentry);
if (they_are_dirs) {
- drop_nlink(new_dentry->d_inode);
+ drop_nlink(d_inode(new_dentry));
drop_nlink(old_dir);
}
} else if (they_are_dirs) {
return 0;
}
+EXPORT_SYMBOL(simple_rename);
/**
* simple_setattr - setattr for simple filesystem
*/
int simple_setattr(struct dentry *dentry, struct iattr *iattr)
{
- struct inode *inode = dentry->d_inode;
+ struct inode *inode = d_inode(dentry);
int error;
error = inode_change_ok(inode, iattr);
unlock_page(page);
return 0;
}
+EXPORT_SYMBOL(simple_readpage);
int simple_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
}
return 0;
}
+EXPORT_SYMBOL(simple_write_begin);
/**
* simple_write_end - .write_end helper for non-block-device FSes
return copied;
}
+EXPORT_SYMBOL(simple_write_end);
/*
* the inodes created here are not hashed. If you use iunique to generate
dput(root);
return -ENOMEM;
}
+EXPORT_SYMBOL(simple_fill_super);
static DEFINE_SPINLOCK(pin_fs_lock);
mntput(mnt);
return 0;
}
+EXPORT_SYMBOL(simple_pin_fs);
void simple_release_fs(struct vfsmount **mount, int *count)
{
spin_unlock(&pin_fs_lock);
mntput(mnt);
}
+EXPORT_SYMBOL(simple_release_fs);
/**
* simple_read_from_buffer - copy data from the buffer to user space
*ppos = pos + count;
return count;
}
+EXPORT_SYMBOL(simple_read_from_buffer);
/**
* simple_write_to_buffer - copy data from user space to the buffer
*ppos = pos + count;
return count;
}
+EXPORT_SYMBOL(simple_write_to_buffer);
/**
* memory_read_from_buffer - copy data from the buffer
return count;
}
+EXPORT_SYMBOL(memory_read_from_buffer);
/*
* Transaction based IO.
smp_mb();
ar->size = n;
}
+EXPORT_SYMBOL(simple_transaction_set);
char *simple_transaction_get(struct file *file, const char __user *buf, size_t size)
{
return ar->data;
}
+EXPORT_SYMBOL(simple_transaction_get);
ssize_t simple_transaction_read(struct file *file, char __user *buf, size_t size, loff_t *pos)
{
return 0;
return simple_read_from_buffer(buf, size, pos, ar->data, ar->size);
}
+EXPORT_SYMBOL(simple_transaction_read);
int simple_transaction_release(struct inode *inode, struct file *file)
{
free_page((unsigned long)file->private_data);
return 0;
}
+EXPORT_SYMBOL(simple_transaction_release);
/* Simple attribute files */
return nonseekable_open(inode, file);
}
+EXPORT_SYMBOL_GPL(simple_attr_open);
int simple_attr_release(struct inode *inode, struct file *file)
{
kfree(file->private_data);
return 0;
}
+EXPORT_SYMBOL_GPL(simple_attr_release); /* GPL-only? This? Really? */
/* read from the buffer that is filled with the get function */
ssize_t simple_attr_read(struct file *file, char __user *buf,
mutex_unlock(&attr->mutex);
return ret;
}
+EXPORT_SYMBOL_GPL(simple_attr_read);
/* interpret the buffer as a number to call the set function with */
ssize_t simple_attr_write(struct file *file, const char __user *buf,
mutex_unlock(&attr->mutex);
return ret;
}
+EXPORT_SYMBOL_GPL(simple_attr_write);
/**
* generic_fh_to_dentry - generic helper for the fh_to_dentry export operation
EXPORT_SYMBOL_GPL(generic_fh_to_parent);
/**
- * generic_file_fsync - generic fsync implementation for simple filesystems
+ * __generic_file_fsync - generic fsync implementation for simple filesystems
+ *
* @file: file to synchronize
+ * @start: start offset in bytes
+ * @end: end offset in bytes (inclusive)
* @datasync: only synchronize essential metadata if true
*
* This is a generic implementation of the fsync method for simple
* filesystems which track all non-inode metadata in the buffers list
* hanging off the address_space structure.
*/
-int generic_file_fsync(struct file *file, loff_t start, loff_t end,
- int datasync)
+int __generic_file_fsync(struct file *file, loff_t start, loff_t end,
+ int datasync)
{
struct inode *inode = file->f_mapping->host;
int err;
mutex_lock(&inode->i_mutex);
ret = sync_mapping_buffers(inode->i_mapping);
- if (!(inode->i_state & I_DIRTY))
+ if (!(inode->i_state & I_DIRTY_ALL))
goto out;
if (datasync && !(inode->i_state & I_DIRTY_DATASYNC))
goto out;
err = sync_inode_metadata(inode, 1);
if (ret == 0)
ret = err;
+
out:
mutex_unlock(&inode->i_mutex);
return ret;
}
+EXPORT_SYMBOL(__generic_file_fsync);
+
+/**
+ * generic_file_fsync - generic fsync implementation for simple filesystems
+ * with flush
+ * @file: file to synchronize
+ * @start: start offset in bytes
+ * @end: end offset in bytes (inclusive)
+ * @datasync: only synchronize essential metadata if true
+ *
+ */
+
+int generic_file_fsync(struct file *file, loff_t start, loff_t end,
+ int datasync)
+{
+ struct inode *inode = file->f_mapping->host;
+ int err;
+
+ err = __generic_file_fsync(file, start, end, datasync);
+ if (err)
+ return err;
+ return blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
+}
EXPORT_SYMBOL(generic_file_fsync);
/**
{
return 0;
}
-
-EXPORT_SYMBOL(dcache_dir_close);
-EXPORT_SYMBOL(dcache_dir_lseek);
-EXPORT_SYMBOL(dcache_dir_open);
-EXPORT_SYMBOL(dcache_readdir);
-EXPORT_SYMBOL(generic_read_dir);
-EXPORT_SYMBOL(mount_pseudo);
-EXPORT_SYMBOL(simple_write_begin);
-EXPORT_SYMBOL(simple_write_end);
-EXPORT_SYMBOL(simple_dir_inode_operations);
-EXPORT_SYMBOL(simple_dir_operations);
-EXPORT_SYMBOL(simple_empty);
-EXPORT_SYMBOL(simple_fill_super);
-EXPORT_SYMBOL(simple_getattr);
-EXPORT_SYMBOL(simple_open);
-EXPORT_SYMBOL(simple_link);
-EXPORT_SYMBOL(simple_lookup);
-EXPORT_SYMBOL(simple_pin_fs);
-EXPORT_SYMBOL(simple_readpage);
-EXPORT_SYMBOL(simple_release_fs);
-EXPORT_SYMBOL(simple_rename);
-EXPORT_SYMBOL(simple_rmdir);
-EXPORT_SYMBOL(simple_statfs);
EXPORT_SYMBOL(noop_fsync);
-EXPORT_SYMBOL(simple_unlink);
-EXPORT_SYMBOL(simple_read_from_buffer);
-EXPORT_SYMBOL(simple_write_to_buffer);
-EXPORT_SYMBOL(memory_read_from_buffer);
-EXPORT_SYMBOL(simple_transaction_set);
-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_release);
-EXPORT_SYMBOL_GPL(simple_attr_read);
-EXPORT_SYMBOL_GPL(simple_attr_write);
+
+void kfree_put_link(struct inode *unused, void *cookie)
+{
+ kfree(cookie);
+}
+EXPORT_SYMBOL(kfree_put_link);
+
+void free_page_put_link(struct inode *unused, void *cookie)
+{
+ free_page((unsigned long) cookie);
+}
+EXPORT_SYMBOL(free_page_put_link);
+
+/*
+ * nop .set_page_dirty method so that people can use .page_mkwrite on
+ * anon inodes.
+ */
+static int anon_set_page_dirty(struct page *page)
+{
+ return 0;
+};
+
+/*
+ * A single inode exists for all anon_inode files. Contrary to pipes,
+ * anon_inode inodes have no associated per-instance data, so we need
+ * only allocate one of them.
+ */
+struct inode *alloc_anon_inode(struct super_block *s)
+{
+ static const struct address_space_operations anon_aops = {
+ .set_page_dirty = anon_set_page_dirty,
+ };
+ struct inode *inode = new_inode_pseudo(s);
+
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+
+ inode->i_ino = get_next_ino();
+ inode->i_mapping->a_ops = &anon_aops;
+
+ /*
+ * Mark the inode dirty from the very beginning,
+ * that way it will never be moved to the dirty
+ * list because mark_inode_dirty() will think
+ * that it already _is_ on the dirty list.
+ */
+ inode->i_state = I_DIRTY;
+ inode->i_mode = S_IRUSR | S_IWUSR;
+ inode->i_uid = current_fsuid();
+ inode->i_gid = current_fsgid();
+ inode->i_flags |= S_PRIVATE;
+ inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ return inode;
+}
+EXPORT_SYMBOL(alloc_anon_inode);
+
+/**
+ * simple_nosetlease - generic helper for prohibiting leases
+ * @filp: file pointer
+ * @arg: type of lease to obtain
+ * @flp: new lease supplied for insertion
+ * @priv: private data for lm_setup operation
+ *
+ * Generic helper for filesystems that do not wish to allow leases to be set.
+ * All arguments are ignored and it just returns -EINVAL.
+ */
+int
+simple_nosetlease(struct file *filp, long arg, struct file_lock **flp,
+ void **priv)
+{
+ return -EINVAL;
+}
+EXPORT_SYMBOL(simple_nosetlease);
+
+const char *simple_follow_link(struct dentry *dentry, void **cookie)
+{
+ return d_inode(dentry)->i_link;
+}
+EXPORT_SYMBOL(simple_follow_link);
+
+const struct inode_operations simple_symlink_inode_operations = {
+ .follow_link = simple_follow_link,
+ .readlink = generic_readlink
+};
+EXPORT_SYMBOL(simple_symlink_inode_operations);
+
+/*
+ * Operations for a permanently empty directory.
+ */
+static struct dentry *empty_dir_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
+{
+ return ERR_PTR(-ENOENT);
+}
+
+static int empty_dir_getattr(struct vfsmount *mnt, struct dentry *dentry,
+ struct kstat *stat)
+{
+ struct inode *inode = d_inode(dentry);
+ generic_fillattr(inode, stat);
+ return 0;
+}
+
+static int empty_dir_setattr(struct dentry *dentry, struct iattr *attr)
+{
+ return -EPERM;
+}
+
+static int empty_dir_setxattr(struct dentry *dentry, const char *name,
+ const void *value, size_t size, int flags)
+{
+ return -EOPNOTSUPP;
+}
+
+static ssize_t empty_dir_getxattr(struct dentry *dentry, const char *name,
+ void *value, size_t size)
+{
+ return -EOPNOTSUPP;
+}
+
+static int empty_dir_removexattr(struct dentry *dentry, const char *name)
+{
+ return -EOPNOTSUPP;
+}
+
+static ssize_t empty_dir_listxattr(struct dentry *dentry, char *list, size_t size)
+{
+ return -EOPNOTSUPP;
+}
+
+static const struct inode_operations empty_dir_inode_operations = {
+ .lookup = empty_dir_lookup,
+ .permission = generic_permission,
+ .setattr = empty_dir_setattr,
+ .getattr = empty_dir_getattr,
+ .setxattr = empty_dir_setxattr,
+ .getxattr = empty_dir_getxattr,
+ .removexattr = empty_dir_removexattr,
+ .listxattr = empty_dir_listxattr,
+};
+
+static loff_t empty_dir_llseek(struct file *file, loff_t offset, int whence)
+{
+ /* An empty directory has two entries . and .. at offsets 0 and 1 */
+ return generic_file_llseek_size(file, offset, whence, 2, 2);
+}
+
+static int empty_dir_readdir(struct file *file, struct dir_context *ctx)
+{
+ dir_emit_dots(file, ctx);
+ return 0;
+}
+
+static const struct file_operations empty_dir_operations = {
+ .llseek = empty_dir_llseek,
+ .read = generic_read_dir,
+ .iterate = empty_dir_readdir,
+ .fsync = noop_fsync,
+};
+
+
+void make_empty_dir_inode(struct inode *inode)
+{
+ set_nlink(inode, 2);
+ inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
+ inode->i_uid = GLOBAL_ROOT_UID;
+ inode->i_gid = GLOBAL_ROOT_GID;
+ inode->i_rdev = 0;
+ inode->i_size = 0;
+ inode->i_blkbits = PAGE_SHIFT;
+ inode->i_blocks = 0;
+
+ inode->i_op = &empty_dir_inode_operations;
+ inode->i_fop = &empty_dir_operations;
+}
+
+bool is_empty_dir_inode(struct inode *inode)
+{
+ return (inode->i_fop == &empty_dir_operations) &&
+ (inode->i_op == &empty_dir_inode_operations);
+}