/* Some parts of this taken from generic_cont_expand, which turned out
* to be too fragile to do exactly what we need without us having to
* worry about recursive locking in ->write_begin() and ->write_end(). */
static int ocfs2_write_zero_page(struct inode *inode,
u64 size)
{
struct address_space *mapping = inode->i_mapping;
struct page *page;
unsigned long index;
unsigned int offset;
handle_t *handle = NULL;
int ret;
offset = (size & (PAGE_CACHE_SIZE-1)); /* Within page */
/* ugh. in prepare/commit_write, if from==to==start of block, we
** skip the prepare. make sure we never send an offset for the start
** of a block
*/
if ((offset & (inode->i_sb->s_blocksize - 1)) == 0) {
offset++;
}
index = size >> PAGE_CACHE_SHIFT;
page = grab_cache_page(mapping, index);
if (!page) {
ret = -ENOMEM;
mlog_errno(ret);
goto out;
}
ret = ocfs2_prepare_write_nolock(inode, page, offset, offset);
if (ret < 0) {
mlog_errno(ret);
goto out_unlock;
}
if (ocfs2_should_order_data(inode)) {
handle = ocfs2_start_walk_page_trans(inode, page, offset,
offset);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
handle = NULL;
goto out_unlock;
}
}
/* must not update i_size! */
ret = block_commit_write(page, offset, offset);
if (ret < 0)
mlog_errno(ret);
else
ret = 0;
if (handle)
ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
out_unlock:
unlock_page(page);
page_cache_release(page);
out:
return ret;
}
static int ext4_convert_inline_data_to_extent(struct address_space *mapping,
struct inode *inode,
unsigned flags)
{
int ret, needed_blocks;
handle_t *handle = NULL;
int retries = 0, sem_held = 0;
struct page *page = NULL;
unsigned from, to;
struct ext4_iloc iloc;
if (!ext4_has_inline_data(inode)) {
/*
* clear the flag so that no new write
* will trap here again.
*/
ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
return 0;
}
needed_blocks = ext4_writepage_trans_blocks(inode);
ret = ext4_get_inode_loc(inode, &iloc);
if (ret)
return ret;
retry:
handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, needed_blocks);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
handle = NULL;
goto out;
}
/* We cannot recurse into the filesystem as the transaction is already
* started */
flags |= AOP_FLAG_NOFS;
page = grab_cache_page_write_begin(mapping, 0, flags);
if (!page) {
ret = -ENOMEM;
goto out;
}
down_write(&EXT4_I(inode)->xattr_sem);
sem_held = 1;
/* If some one has already done this for us, just exit. */
if (!ext4_has_inline_data(inode)) {
ret = 0;
goto out;
}
from = 0;
to = ext4_get_inline_size(inode);
if (!PageUptodate(page)) {
ret = ext4_read_inline_page(inode, page);
if (ret < 0)
goto out;
}
ret = ext4_destroy_inline_data_nolock(handle, inode);
if (ret)
goto out;
if (ext4_should_dioread_nolock(inode)) {
ret = __block_write_begin(page, from, to,
ext4_get_block_unwritten);
} else
ret = __block_write_begin(page, from, to, ext4_get_block);
if (!ret && ext4_should_journal_data(inode)) {
ret = ext4_walk_page_buffers(handle, page_buffers(page),
from, to, NULL,
do_journal_get_write_access);
}
if (ret) {
unlock_page(page);
page_cache_release(page);
page = NULL;
ext4_orphan_add(handle, inode);
up_write(&EXT4_I(inode)->xattr_sem);
sem_held = 0;
ext4_journal_stop(handle);
handle = NULL;
ext4_truncate_failed_write(inode);
/*
* If truncate failed early the inode might
* still be on the orphan list; we need to
* make sure the inode is removed from the
* orphan list in that case.
*/
if (inode->i_nlink)
ext4_orphan_del(NULL, inode);
}
if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
goto retry;
if (page)
block_commit_write(page, from, to);
out:
if (page) {
unlock_page(page);
page_cache_release(page);
}
if (sem_held)
up_write(&EXT4_I(inode)->xattr_sem);
if (handle)
ext4_journal_stop(handle);
brelse(iloc.bh);
return ret;
}
static int blkdev_commit_write(struct file *file, struct page *page, unsigned from, unsigned to)
{
return block_commit_write(page, from, to);
}