static void ext4_finish_bio(struct bio *bio)
{
int i;
struct bio_vec *bvec;
bio_for_each_segment_all(bvec, bio, i) {
struct page *page = bvec->bv_page;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
struct page *data_page = NULL;
#endif
struct buffer_head *bh, *head;
unsigned bio_start = bvec->bv_offset;
unsigned bio_end = bio_start + bvec->bv_len;
unsigned under_io = 0;
unsigned long flags;
if (!page)
continue;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
if (!page->mapping) {
/* The bounce data pages are unmapped. */
data_page = page;
fscrypt_pullback_bio_page(&page, false);
}
#endif
if (bio->bi_error) {
SetPageError(page);
mapping_set_error(page->mapping, -EIO);
}
bh = head = page_buffers(page);
/*
* We check all buffers in the page under BH_Uptodate_Lock
* to avoid races with other end io clearing async_write flags
*/
local_irq_save(flags);
bit_spin_lock(BH_Uptodate_Lock, &head->b_state);
do {
if (bh_offset(bh) < bio_start ||
bh_offset(bh) + bh->b_size > bio_end) {
if (buffer_async_write(bh))
under_io++;
continue;
}
clear_buffer_async_write(bh);
if (bio->bi_error)
buffer_io_error(bh);
} while ((bh = bh->b_this_page) != head);
bit_spin_unlock(BH_Uptodate_Lock, &head->b_state);
local_irq_restore(flags);
if (!under_io) {
#ifdef CONFIG_EXT4_FS_ENCRYPTION
if (data_page)
fscrypt_restore_control_page(data_page);
#endif
end_page_writeback(page);
}
}
}
void fscrypt_pullback_bio_page(struct page **page, bool restore)
{
struct fscrypt_ctx *ctx;
struct page *bounce_page;
/* The bounce data pages are unmapped. */
if ((*page)->mapping)
return;
/* The bounce data page is unmapped. */
bounce_page = *page;
ctx = (struct fscrypt_ctx *)page_private(bounce_page);
/* restore control page */
*page = ctx->w.control_page;
if (restore)
fscrypt_restore_control_page(bounce_page);
}
