* File Operations *
*******************/
-static loff_t unionfs_llseek(struct file *file, loff_t offset, int origin)
+static ssize_t unionfs_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
{
- loff_t err;
- struct file *hidden_file = NULL;
+ int err;
unionfs_read_lock(file->f_dentry->d_sb);
if ((err = unionfs_file_revalidate(file, 0)))
goto out;
- hidden_file = unionfs_lower_file(file);
- /* always set hidden position to this one */
- hidden_file->f_pos = file->f_pos;
+ err = do_sync_read(unionfs_lower_file(file), buf, count, ppos);
- memcpy(&hidden_file->f_ra, &file->f_ra, sizeof(struct file_ra_state));
-
- if (hidden_file->f_op && hidden_file->f_op->llseek)
- err = hidden_file->f_op->llseek(hidden_file, offset, origin);
- else
- err = generic_file_llseek(hidden_file, offset, origin);
+ /* FIXME: why? */
+ if (err >= 0)
+ touch_atime(unionfs_lower_mnt(file->f_path.dentry),
+ unionfs_lower_dentry(file->f_path.dentry));
- if (err < 0)
- goto out;
- if (err != file->f_pos) {
- file->f_pos = err;
- file->f_version++;
- }
out:
unionfs_read_unlock(file->f_dentry->d_sb);
unionfs_check_file(file);
return err;
}
-static ssize_t unionfs_read(struct file *file, char __user *buf,
- size_t count, loff_t *ppos)
+static ssize_t unionfs_aio_read(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
{
- struct file *hidden_file;
- loff_t pos = *ppos;
+ struct file *file = iocb->ki_filp;
int err;
+#error fixme fxn check_file? read_unlock?
+ err = generic_file_aio_read(iocb, iov, nr_segs, pos);
- unionfs_read_lock(file->f_dentry->d_sb);
- if ((err = unionfs_file_revalidate(file, 0)))
- goto out;
-
- err = -EINVAL;
- hidden_file = unionfs_lower_file(file);
- if (!hidden_file->f_op || !hidden_file->f_op->read)
- goto out;
+ if (err == -EIOCBQUEUED)
+ err = wait_on_sync_kiocb(iocb);
- err = hidden_file->f_op->read(hidden_file, buf, count, &pos);
- *ppos = pos;
+ /* FIXME: why? */
+ if (err >= 0)
+ touch_atime(unionfs_lower_mnt(file->f_path.dentry),
+ unionfs_lower_dentry(file->f_path.dentry));
+#if 0
out:
unionfs_read_unlock(file->f_dentry->d_sb);
unionfs_check_file(file);
+#endif
return err;
}
-
-static ssize_t unionfs_write(struct file *file, const char __user *buf,
- size_t count, loff_t *ppos)
+static ssize_t unionfs_write(struct file * file, const char __user * buf,
+ size_t count, loff_t * ppos)
{
- int err;
- struct file *hidden_file = NULL;
- struct inode *inode;
- struct inode *hidden_inode;
- loff_t pos = *ppos;
- int bstart, bend;
+ int err = 0;
unionfs_read_lock(file->f_dentry->d_sb);
if ((err = unionfs_file_revalidate(file, 1)))
goto out;
- inode = file->f_dentry->d_inode;
-
- bstart = fbstart(file);
- bend = fbend(file);
-
- BUG_ON(bstart == -1);
-
- hidden_file = unionfs_lower_file(file);
- hidden_inode = hidden_file->f_dentry->d_inode;
-
- if (!hidden_file->f_op || !hidden_file->f_op->write) {
- err = -EINVAL;
- goto out;
- }
-
- /* adjust for append -- seek to the end of the file */
- if (file->f_flags & O_APPEND)
- pos = inode->i_size;
-
- err = hidden_file->f_op->write(hidden_file, buf, count, &pos);
-
- /*
- * copy ctime and mtime from lower layer attributes
- * atime is unchanged for both layers
- */
- if (err >= 0)
- fsstack_copy_attr_times(inode, hidden_inode);
-
- *ppos = pos;
+ err = do_sync_write(file, buf, count, ppos);
- /* update this inode's size */
- if (pos > inode->i_size)
- inode->i_size = pos;
out:
unionfs_read_unlock(file->f_dentry->d_sb);
unionfs_check_file(file);
}
struct file_operations unionfs_main_fops = {
- .llseek = unionfs_llseek,
+ .llseek = generic_file_llseek,
.read = unionfs_read,
+ .aio_read = unionfs_aio_read,
.write = unionfs_write,
+ .aio_write = generic_file_aio_write,
.readdir = unionfs_file_readdir,
- .poll = unionfs_poll,
.unlocked_ioctl = unionfs_ioctl,
.mmap = unionfs_mmap,
.open = unionfs_open,
.flush = unionfs_flush,
.release = unionfs_file_release,
- .fsync = unionfs_fsync,
- .fasync = unionfs_fasync,
+ .fsync = file_fsync,
};
--- /dev/null
+/*
+ * Copyright (c) 2003-2007 Erez Zadok
+ * Copyright (c) 2003-2006 Charles P. Wright
+ * Copyright (c) 2005-2007 Josef 'Jeff' Sipek
+ * Copyright (c) 2005-2006 Junjiro Okajima
+ * Copyright (c) 2006 Shaya Potter
+ * Copyright (c) 2005 Arun M. Krishnakumar
+ * Copyright (c) 2004-2006 David P. Quigley
+ * Copyright (c) 2003-2004 Mohammad Nayyer Zubair
+ * Copyright (c) 2003 Puja Gupta
+ * Copyright (c) 2003 Harikesavan Krishnan
+ * Copyright (c) 2003-2007 Stony Brook University
+ * Copyright (c) 2003-2007 The Research Foundation of State University of New York
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "union.h"
+
+int unionfs_writepage(struct page *page, struct writeback_control *wbc)
+{
+ int err = -EIO;
+ struct inode *inode;
+ struct inode *lower_inode;
+ struct page *lower_page;
+ char *kaddr, *lower_kaddr;
+
+ inode = page->mapping->host;
+ lower_inode = unionfs_lower_inode(inode);
+
+ /* find lower page (returns a locked page) */
+ lower_page = grab_cache_page(lower_inode->i_mapping, page->index);
+ if (!lower_page)
+ goto out;
+
+ /* get page address, and encode it */
+ kaddr = kmap(page);
+ lower_kaddr = kmap(lower_page);
+
+ memcpy(lower_kaddr, kaddr, PAGE_CACHE_SIZE);
+
+ kunmap(page);
+ kunmap(lower_page);
+
+ /* call lower writepage (expects locked page) */
+ err = lower_inode->i_mapping->a_ops->writepage(lower_page, wbc);
+
+ /*
+ * update mtime and ctime of lower level file system
+ * unionfs' mtime and ctime are updated by generic_file_write
+ */
+ lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME;
+
+ page_cache_release(lower_page); /* b/c grab_cache_page increased refcnt */
+
+ if (err)
+ ClearPageUptodate(page);
+ else
+ SetPageUptodate(page);
+
+out:
+ unlock_page(page);
+
+ return err;
+}
+
+/*
+ * readpage is called from generic_page_read and the fault handler.
+ * If your file system uses generic_page_read for the read op, it
+ * must implement readpage.
+ *
+ * Readpage expects a locked page, and must unlock it.
+ */
+int unionfs_do_readpage(struct file *file, struct page *page)
+{
+ int err = -EIO;
+ struct dentry *dentry;
+ struct file *lower_file = NULL;
+ struct inode *inode, *lower_inode;
+ char *page_data;
+ struct page *lower_page;
+ char *lower_page_data;
+
+ dentry = file->f_dentry;
+ if (UNIONFS_F(file) == NULL) {
+ err = -ENOENT;
+ goto out_err;
+ }
+
+ lower_file = unionfs_lower_file(file);
+ inode = dentry->d_inode;
+ lower_inode = unionfs_lower_inode(inode);
+
+ lower_page = NULL;
+
+ /* find lower page (returns a locked page) */
+ lower_page = read_cache_page(lower_inode->i_mapping,
+ page->index,
+ (filler_t *) lower_inode->i_mapping->
+ a_ops->readpage, (void *)lower_file);
+
+ if (IS_ERR(lower_page)) {
+ err = PTR_ERR(lower_page);
+ lower_page = NULL;
+ goto out_release;
+ }
+
+ /*
+ * wait for the page data to show up
+ * (signaled by readpage as unlocking the page)
+ */
+ wait_on_page_locked(lower_page);
+ if (!PageUptodate(lower_page)) {
+ /*
+ * call readpage() again if we returned from wait_on_page with a
+ * page that's not up-to-date; that can happen when a partial
+ * page has a few buffers which are ok, but not the whole
+ * page.
+ */
+ lock_page(lower_page);
+ err = lower_inode->i_mapping->a_ops->readpage(lower_file,
+ lower_page);
+ if (err) {
+ lower_page = NULL;
+ goto out_release;
+ }
+
+ wait_on_page_locked(lower_page);
+ if (!PageUptodate(lower_page)) {
+ err = -EIO;
+ goto out_release;
+ }
+ }
+
+ /* map pages, get their addresses */
+ page_data = (char *)kmap(page);
+ lower_page_data = (char *)kmap(lower_page);
+
+ memcpy(page_data, lower_page_data, PAGE_CACHE_SIZE);
+
+ err = 0;
+
+ kunmap(lower_page);
+ kunmap(page);
+
+out_release:
+ if (lower_page)
+ page_cache_release(lower_page); /* undo read_cache_page */
+
+ if (err == 0)
+ SetPageUptodate(page);
+ else
+ ClearPageUptodate(page);
+
+out_err:
+ return err;
+}
+
+int unionfs_readpage(struct file *file, struct page *page)
+{
+ int err;
+
+ err = unionfs_do_readpage(file, page);
+
+ /*
+ * we have to unlock our page, b/c we _might_ have gotten a locked page.
+ * but we no longer have to wakeup on our page here, b/c UnlockPage does
+ * it
+ */
+
+ unlock_page(page);
+
+ return err;
+}
+
+int unionfs_prepare_write(struct file *file, struct page *page, unsigned from,
+ unsigned to)
+{
+ return 0;
+}
+
+int unionfs_commit_write(struct file *file, struct page *page, unsigned from,
+ unsigned to)
+{
+ int err = -ENOMEM;
+ struct inode *inode, *lower_inode;
+ struct file *lower_file = NULL;
+ loff_t pos;
+ unsigned bytes = to - from;
+ char *page_data = NULL;
+ mm_segment_t old_fs;
+
+ BUG_ON(file == NULL);
+
+ inode = page->mapping->host; /* CPW: Moved below print_entry_location */
+ lower_inode = unionfs_lower_inode(inode);
+
+ if (UNIONFS_F(file) != NULL)
+ lower_file = unionfs_lower_file(file);
+
+ BUG_ON(lower_file == NULL); /* FIXME: is this assertion right here? */
+
+ page_data = (char *)kmap(page);
+ lower_file->f_pos = (page->index << PAGE_CACHE_SHIFT) + from;
+
+ /* SP: I use vfs_write instead of copying page data and the
+ * prepare_write/commit_write combo because file system's like
+ * GFS/OCFS2 don't like things touching those directly,
+ * calling the underlying write op, while a little bit slower, will
+ * call all the FS specific code as well
+ */
+ old_fs = get_fs();
+ set_fs(KERNEL_DS);
+ err = vfs_write(lower_file, page_data + from, bytes, &lower_file->f_pos);
+ set_fs(old_fs);
+
+ kunmap(page);
+
+ if (err < 0)
+ goto out;
+
+ inode->i_blocks = lower_inode->i_blocks;
+ /* we may have to update i_size */
+ pos = ((loff_t) page->index << PAGE_CACHE_SHIFT) + to;
+ if (pos > i_size_read(inode))
+ i_size_write(inode, pos);
+
+ /*
+ * update mtime and ctime of lower level file system
+ * unionfs' mtime and ctime are updated by generic_file_write
+ */
+ lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME;
+
+ mark_inode_dirty_sync(inode);
+
+out:
+ if (err < 0)
+ ClearPageUptodate(page);
+
+ return err; /* assume all is ok */
+}
+
+/* FIXME: does this make sense? */
+sector_t unionfs_bmap(struct address_space * mapping, sector_t block)
+{
+ int err = 0;
+ struct inode *inode, *lower_inode;
+
+ inode = (struct inode *)mapping->host;
+ lower_inode = unionfs_lower_inode(inode);
+
+ if (lower_inode->i_mapping->a_ops->bmap)
+ err =
+ lower_inode->i_mapping->a_ops->bmap(lower_inode->i_mapping,
+ block);
+ return err;
+}
+
+void unionfs_sync_page(struct page *page)
+{
+ struct inode *inode;
+ struct inode *lower_inode;
+ struct page *lower_page;
+ struct address_space *mapping = page->mapping;
+
+ inode = page->mapping->host; /* CPW: Moved below print_entry_location */
+ lower_inode = unionfs_lower_inode(inode);
+
+ /* find lower page (returns a locked page) */
+ lower_page = grab_cache_page(lower_inode->i_mapping, page->index);
+ if (!lower_page)
+ goto out;
+
+ /* do the actual sync */
+ if (mapping && mapping->a_ops && mapping->a_ops->sync_page)
+ mapping->a_ops->sync_page(page);
+
+ unlock_page(lower_page); /* b/c grab_cache_page locked it */
+ page_cache_release(lower_page); /* b/c grab_cache_page increased refcnt */
+
+out:
+
+ return;
+}
+
+struct address_space_operations unionfs_aops = {
+ .writepage = unionfs_writepage,
+ .readpage = unionfs_readpage,
+ .prepare_write = unionfs_prepare_write,
+ .commit_write = unionfs_commit_write,
+ .bmap = unionfs_bmap,
+ .sync_page = unionfs_sync_page,
+};
+
projects / wrapfs-5.3.y.git / commitdiff