/*
* support function for mpage_readpages. The fs supplied get_block might
* return an up to date buffer. This is used to map that buffer into
* the page, which allows readpage to avoid triggering a duplicate call
* to get_block.
*
* The idea is to avoid adding buffers to pages that don't already have
* them. So when the buffer is up to date and the page size == block size,
* this marks the page up to date instead of adding new buffers.
*/
static void
map_buffer_to_page(struct page *page, struct buffer_head *bh, int page_block)
{
struct _inode *inode = tx_cache_get_inode_ro(page->mapping->host);
struct buffer_head *page_bh, *head;
int block = 0;
if (!page_has_buffers(page)) {
/*
* don't make any buffers if there is only one buffer on
* the page and the page just needs to be set up to date
*/
if (inode->i_blkbits == PAGE_CACHE_SHIFT &&
buffer_uptodate(bh)) {
SetPageUptodate(page);
return;
}
create_empty_buffers(page, 1 << inode->i_blkbits, 0);
}
head = page_buffers(page);
page_bh = head;
do {
if (block == page_block) {
page_bh->b_state = bh->b_state;
page_bh->b_bdev = bh->b_bdev;
page_bh->b_blocknr = bh->b_blocknr;
break;
}
page_bh = page_bh->b_this_page;
block++;
} while (page_bh != head);
}
long do_fsync(struct file *file, int datasync)
{
int ret;
int err;
struct address_space *mapping = file->f_mapping;
if (live_transaction()){
/* DEP 5/27/10 - Defer fsync until commit. */
struct deferred_object_operation *def_op;
txobj_thread_list_node_t *list_node = workset_has_object(&file->f_mapping->host->xobj);
if (!list_node) {
tx_cache_get_file_ro(file);
tx_cache_get_inode_ro(file->f_mapping->host);
list_node = workset_has_object(&file->f_mapping->host->xobj);
}
def_op = alloc_deferred_object_operation();
INIT_LIST_HEAD(&def_op->list);
def_op->type = DEFERRED_TYPE_FSYNC;
def_op->u.fsync.datasync = datasync;
def_op->u.fsync.file = file;
/* DEP: Pin the file until the sync is executed */
tx_atomic_inc_not_zero(&file->f_count);
// XXX: Could probably use something finer grained here.
WORKSET_LOCK(current->transaction);
list_add(&def_op->list, &list_node->deferred_operations);
WORKSET_UNLOCK(current->transaction);
return 0;
}
if (!file->f_op || !file->f_op->fsync) {
/* Why? We can still call filemap_fdatawrite */
ret = -EINVAL;
goto out;
}
ret = filemap_fdatawrite(mapping);
/*
* We need to protect against concurrent writers, which could cause
* livelocks in fsync_buffers_list().
*/
if (!committing_transaction())
mutex_lock(&mapping->host->i_mutex);
err = file->f_op->fsync(file, file_get_dentry(file), datasync);
if (!ret)
ret = err;
if (!committing_transaction())
mutex_unlock(&mapping->host->i_mutex);
err = filemap_fdatawait(mapping);
if (!ret)
ret = err;
out:
return ret;
}
/*
* Generic function to fsync a file.
*
* filp may be NULL if called via the msync of a vma.
*/
int file_fsync(struct file *filp, struct dentry *dentry, int datasync)
{
struct inode * inode = tx_cache_get_dentry(dentry)->d_inode;
struct super_block * sb;
int ret, err;
/* sync the inode to buffers */
ret = write_inode_now(inode, 0);
/* sync the superblock to buffers */
sb = tx_cache_get_inode_ro(inode)->i_sb;
lock_super(sb);
if (sb->s_op->write_super)
sb->s_op->write_super(sb);
unlock_super(sb);
/* .. finally sync the buffers to disk */
err = sync_blockdev(sb->s_bdev);
if (!ret)
ret = err;
return ret;
}
