Commit 902b22f3 authored by David Woodhouse's avatar David Woodhouse Committed by Chris Mason
Browse files

Btrfs: Remove broken optimisations in end_bio functions. 



These ended up freeing objects while they were still using them. Under
guidance from Chris, just rip out the 'clever' bits and do things the
simple way.

Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 53863232

fs/btrfs/extent_io.c

+21 −138
Original line number Diff line number Diff line
@@ -15,6 +15,8 @@ 
#include "extent_io.h"

#include "extent_map.h"

#include "compat.h"

#include "ctree.h"

#include "btrfs_inode.h"



/* temporary define until extent_map moves out of btrfs */

struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
@@ -1394,15 +1396,11 @@ static int end_bio_extent_writepage(struct bio *bio, 
{

	int uptodate = err == 0;

	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;

	struct extent_state *state = bio->bi_private;

	struct extent_io_tree *tree = state->tree;

	struct rb_node *node;

	struct extent_io_tree *tree;

	u64 start;

	u64 end;

	u64 cur;

	int whole_page;

	int ret;

	unsigned long flags;



#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)

	if (bio->bi_size)
@@ -1410,6 +1408,8 @@ static int end_bio_extent_writepage(struct bio *bio, 
#endif

	do {

		struct page *page = bvec->bv_page;

		tree = &BTRFS_I(page->mapping->host)->io_tree;



		start = ((u64)page->index << PAGE_CACHE_SHIFT) +

			 bvec->bv_offset;

		end = start + bvec->bv_len - 1;
@@ -1423,7 +1423,7 @@ static int end_bio_extent_writepage(struct bio *bio, 
			prefetchw(&bvec->bv_page->flags);

		if (tree->ops && tree->ops->writepage_end_io_hook) {

			ret = tree->ops->writepage_end_io_hook(page, start,

						       end, state, uptodate);

						       end, NULL, uptodate);

			if (ret)

				uptodate = 0;

		}
@@ -1431,9 +1431,8 @@ static int end_bio_extent_writepage(struct bio *bio, 
		if (!uptodate && tree->ops &&

		    tree->ops->writepage_io_failed_hook) {

			ret = tree->ops->writepage_io_failed_hook(bio, page,

							 start, end, state);

							 start, end, NULL);

			if (ret == 0) {

				state = NULL;

				uptodate = (err == 0);

				continue;

			}
@@ -1445,68 +1444,7 @@ static int end_bio_extent_writepage(struct bio *bio, 
			SetPageError(page);

		}



		/*

		 * bios can get merged in funny ways, and so we need to

		 * be careful with the state variable.  We know the

		 * state won't be merged with others because it has

		 * WRITEBACK set, but we can't be sure each biovec is

		 * sequential in the file.  So, if our cached state

		 * doesn't match the expected end, search the tree

		 * for the correct one.

		 */



		spin_lock_irqsave(&tree->lock, flags);

		if (!state || state->end != end) {

			state = NULL;

			node = __etree_search(tree, start, NULL, NULL);

			if (node) {

				state = rb_entry(node, struct extent_state,

						 rb_node);

				if (state->end != end ||

				    !(state->state & EXTENT_WRITEBACK))

					state = NULL;

			}

			if (!state) {

				spin_unlock_irqrestore(&tree->lock, flags);

				clear_extent_writeback(tree, start,

						       end, GFP_ATOMIC);

				goto next_io;

			}

		}

		cur = end;

		while(1) {

			struct extent_state *clear = state;

			cur = state->start;

			node = rb_prev(&state->rb_node);

			if (node) {

				state = rb_entry(node,

						 struct extent_state,

						 rb_node);

			} else {

				state = NULL;

			}



			clear_state_bit(tree, clear, EXTENT_WRITEBACK,

					1, 0);

			if (cur == start)

				break;

			if (cur < start) {

				WARN_ON(1);

				break;

			}

			if (!node)

				break;

		}

		/* before releasing the lock, make sure the next state

		 * variable has the expected bits set and corresponds

		 * to the correct offsets in the file

		 */

		if (state && (state->end + 1 != start ||

		    !(state->state & EXTENT_WRITEBACK))) {

			state = NULL;

		}

		spin_unlock_irqrestore(&tree->lock, flags);

next_io:

		clear_extent_writeback(tree, start, end, GFP_ATOMIC);



		if (whole_page)

			end_page_writeback(page);
@@ -1539,13 +1477,9 @@ static int end_bio_extent_readpage(struct bio *bio, 
{

	int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);

	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;

	struct extent_state *state = bio->bi_private;

	struct extent_io_tree *tree = state->tree;

	struct rb_node *node;

	struct extent_io_tree *tree;

	u64 start;

	u64 end;

	u64 cur;

	unsigned long flags;

	int whole_page;

	int ret;
@@ -1556,6 +1490,8 @@ static int end_bio_extent_readpage(struct bio *bio, 


	do {

		struct page *page = bvec->bv_page;

		tree = &BTRFS_I(page->mapping->host)->io_tree;



		start = ((u64)page->index << PAGE_CACHE_SHIFT) +

			bvec->bv_offset;

		end = start + bvec->bv_len - 1;
@@ -1570,80 +1506,26 @@ static int end_bio_extent_readpage(struct bio *bio, 


		if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {

			ret = tree->ops->readpage_end_io_hook(page, start, end,

							      state);

							      NULL);

			if (ret)

				uptodate = 0;

		}

		if (!uptodate && tree->ops &&

		    tree->ops->readpage_io_failed_hook) {

			ret = tree->ops->readpage_io_failed_hook(bio, page,

							 start, end, state);

							 start, end, NULL);

			if (ret == 0) {

				state = NULL;

				uptodate =

					test_bit(BIO_UPTODATE, &bio->bi_flags);

				continue;

			}

		}



		spin_lock_irqsave(&tree->lock, flags);

		if (!state || state->end != end) {

			state = NULL;

			node = __etree_search(tree, start, NULL, NULL);

			if (node) {

				state = rb_entry(node, struct extent_state,

						 rb_node);

				if (state->end != end ||

				    !(state->state & EXTENT_LOCKED))

					state = NULL;

			}

			if (!state) {

				spin_unlock_irqrestore(&tree->lock, flags);

		if (uptodate)

			set_extent_uptodate(tree, start, end,

					    GFP_ATOMIC);

		unlock_extent(tree, start, end, GFP_ATOMIC);

				goto next_io;

			}

		}



		cur = end;

		while(1) {

			struct extent_state *clear = state;

			cur = state->start;

			node = rb_prev(&state->rb_node);

			if (node) {

				state = rb_entry(node,

					 struct extent_state,

					 rb_node);

			} else {

				state = NULL;

			}

			if (uptodate) {

				set_state_cb(tree, clear, EXTENT_UPTODATE);

				clear->state |= EXTENT_UPTODATE;

			}

			clear_state_bit(tree, clear, EXTENT_LOCKED,

					1, 0);

			if (cur == start)

				break;

			if (cur < start) {

				WARN_ON(1);

				break;

			}

			if (!node)

				break;

		}

		/* before releasing the lock, make sure the next state

		 * variable has the expected bits set and corresponds

		 * to the correct offsets in the file

		 */

		if (state && (state->end + 1 != start ||

		    !(state->state & EXTENT_LOCKED))) {

			state = NULL;

		}

		spin_unlock_irqrestore(&tree->lock, flags);

next_io:

		if (whole_page) {

			if (uptodate) {

				SetPageUptodate(page);
@@ -1683,8 +1565,7 @@ static int end_bio_extent_preparewrite(struct bio *bio, 
{

	const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);

	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;

	struct extent_state *state = bio->bi_private;

	struct extent_io_tree *tree = state->tree;

	struct extent_io_tree *tree;

	u64 start;

	u64 end;
@@ -1695,6 +1576,8 @@ static int end_bio_extent_preparewrite(struct bio *bio, 


	do {

		struct page *page = bvec->bv_page;

		tree = &BTRFS_I(page->mapping->host)->io_tree;



		start = ((u64)page->index << PAGE_CACHE_SHIFT) +

			bvec->bv_offset;

		end = start + bvec->bv_len - 1;
@@ -1765,7 +1648,7 @@ static int submit_one_bio(int rw, struct bio *bio, int mirror_num) 
	BUG_ON(state->end != end);

	spin_unlock_irq(&tree->lock);



	bio->bi_private = state;

	bio->bi_private = NULL;



	bio_get(bio);