#include <linux/slab.h>
#include <linux/mount.h>
#include <linux/vfs.h>
+#include <linux/quotaops.h>
#include <linux/mutex.h>
#include <linux/exportfs.h>
#include <linux/writeback.h>
return NULL;
}
-int simple_sync_file(struct file * file, struct dentry *dentry, int datasync)
-{
- return 0;
-}
-
int dcache_dir_open(struct inode *inode, struct file *file)
{
static struct qstr cursor_name = {.len = 1, .name = "."};
.llseek = dcache_dir_lseek,
.read = generic_read_dir,
.readdir = dcache_readdir,
- .fsync = simple_sync_file,
+ .fsync = noop_fsync,
};
const struct inode_operations simple_dir_inode_operations = {
return 0;
}
+/**
+ * simple_setsize - handle core mm and vfs requirements for file size change
+ * @inode: inode
+ * @newsize: new file size
+ *
+ * Returns 0 on success, -error on failure.
+ *
+ * simple_setsize must be called with inode_mutex held.
+ *
+ * simple_setsize will check that the requested new size is OK (see
+ * inode_newsize_ok), and then will perform the necessary i_size update
+ * and pagecache truncation (if necessary). It will be typically be called
+ * from the filesystem's setattr function when ATTR_SIZE is passed in.
+ *
+ * The inode itself must have correct permissions and attributes to allow
+ * i_size to be changed, this function then just checks that the new size
+ * requested is valid.
+ *
+ * In the case of simple in-memory filesystems with inodes stored solely
+ * in the inode cache, and file data in the pagecache, nothing more needs
+ * to be done to satisfy a truncate request. Filesystems with on-disk
+ * blocks for example will need to free them in the case of truncate, in
+ * that case it may be easier not to use simple_setsize (but each of its
+ * components will likely be required at some point to update pagecache
+ * and inode etc).
+ */
+int simple_setsize(struct inode *inode, loff_t newsize)
+{
+ loff_t oldsize;
+ int error;
+
+ error = inode_newsize_ok(inode, newsize);
+ if (error)
+ return error;
+
+ oldsize = inode->i_size;
+ i_size_write(inode, newsize);
+ truncate_pagecache(inode, oldsize, newsize);
+
+ return error;
+}
+EXPORT_SYMBOL(simple_setsize);
+
+/**
+ * simple_setattr - setattr for simple in-memory filesystem
+ * @dentry: dentry
+ * @iattr: iattr structure
+ *
+ * Returns 0 on success, -error on failure.
+ *
+ * simple_setattr implements setattr for an in-memory filesystem which
+ * does not store its own file data or metadata (eg. uses the page cache
+ * and inode cache as its data store).
+ */
+int simple_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+ struct inode *inode = dentry->d_inode;
+ int error;
+
+ error = inode_change_ok(inode, iattr);
+ if (error)
+ return error;
+
+ if (iattr->ia_valid & ATTR_SIZE) {
+ error = simple_setsize(inode, iattr->ia_size);
+ if (error)
+ return error;
+ }
+
+ generic_setattr(inode, iattr);
+
+ return error;
+}
+EXPORT_SYMBOL(simple_setattr);
+
int simple_readpage(struct file *file, struct page *page)
{
clear_highpage(page);
* unique inode values later for this filesystem, then you must take care
* to pass it an appropriate max_reserved value to avoid collisions.
*/
-int simple_fill_super(struct super_block *s, int magic, struct tree_descr *files)
+int simple_fill_super(struct super_block *s, unsigned long magic,
+ struct tree_descr *files)
{
struct inode *inode;
struct dentry *root;
}
EXPORT_SYMBOL_GPL(generic_fh_to_parent);
-int simple_fsync(struct file *file, struct dentry *dentry, int datasync)
+/**
+ * generic_file_fsync - generic fsync implementation for simple filesystems
+ * @file: file to synchronize
+ * @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, int datasync)
{
struct writeback_control wbc = {
.sync_mode = WB_SYNC_ALL,
.nr_to_write = 0, /* metadata-only; caller takes care of data */
};
- struct inode *inode = dentry->d_inode;
+ struct inode *inode = file->f_mapping->host;
int err;
int ret;
ret = err;
return ret;
}
-EXPORT_SYMBOL(simple_fsync);
+EXPORT_SYMBOL(generic_file_fsync);
+
+/*
+ * No-op implementation of ->fsync for in-memory filesystems.
+ */
+int noop_fsync(struct file *file, int datasync)
+{
+ return 0;
+}
EXPORT_SYMBOL(dcache_dir_close);
EXPORT_SYMBOL(dcache_dir_lseek);
EXPORT_SYMBOL(simple_rename);
EXPORT_SYMBOL(simple_rmdir);
EXPORT_SYMBOL(simple_statfs);
-EXPORT_SYMBOL(simple_sync_file);
+EXPORT_SYMBOL(noop_fsync);
EXPORT_SYMBOL(simple_unlink);
EXPORT_SYMBOL(simple_read_from_buffer);
EXPORT_SYMBOL(simple_write_to_buffer);
git.openpandora.org / pandora-kernel.git / blobdiff