Messages in this thread Patch in this message | | | Date | Sun, 05 May 2002 13:54:28 -0700 | From | Andrew Morton <> | Subject | [patch 3/10] Allow truncate to discard unmapped buffers |
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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.
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--- 2.5.13/fs/buffer.c~truncate-leak Sun May 5 13:32:00 2002 +++ 2.5.13-akpm/fs/buffer.c Sun May 5 13:32:37 2002 @@ -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); - bh->b_bdev = NULL; - clear_buffer_mapped(bh); - clear_buffer_req(bh); - clear_buffer_new(bh); - unlock_buffer(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); } /** --- 2.5.13/fs/jbd/transaction.c~truncate-leak Sun May 5 13:32:00 2002 +++ 2.5.13-akpm/fs/jbd/transaction.c Sun May 5 13:32:37 2002 @@ -1587,7 +1587,7 @@ static int __journal_try_to_free_buffer( 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_ 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 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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