Commit 6c8dd336 authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds

[PATCH] Allow truncate to discard unmapped buffers

The buffer state "uptodate, dirty, unmapped" is legal.  It occurs when
a mapped page with attached buffers which is over a hole is dirtied.

So discard_buffer() needs to be able to discard those buffers as well;
otherwise the page ends up clean, with dirty buffers and is unfreeable.
parent 22eca178
......@@ -1091,17 +1091,15 @@ EXPORT_SYMBOL(set_bh_page);
/*
* Called when truncating a buffer on a page completely.
*/
static void discard_buffer(struct buffer_head * bh)
static /* inline */ void discard_buffer(struct buffer_head * bh)
{
if (buffer_mapped(bh)) {
clear_buffer_dirty(bh);
lock_buffer(bh);
clear_buffer_dirty(bh);
bh->b_bdev = NULL;
clear_buffer_mapped(bh);
clear_buffer_req(bh);
clear_buffer_new(bh);
unlock_buffer(bh);
}
}
/**
......
......@@ -1587,7 +1587,7 @@ static int __journal_try_to_free_buffer(struct buffer_head *bh,
goto out;
}
if (!buffer_uptodate(bh))
if (!buffer_uptodate(bh)) /* AKPM: why? */
goto out;
if (jh->b_next_transaction != 0)
......@@ -1775,9 +1775,6 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh)
BUFFER_TRACE(bh, "entry");
if (!buffer_mapped(bh))
return 1;
/* It is safe to proceed here without the
* journal_datalist_spinlock because the buffers cannot be
* stolen by try_to_free_buffers as long as we are holding the
......
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