From 902b22f341efa00be802418a0a8c57bddcd269a6 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Wed, 20 Aug 2008 08:51:49 -0400 Subject: [PATCH] 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: David Woodhouse Signed-off-by: Chris Mason --- fs/btrfs/extent_io.c | 159 ++++++------------------------------------- 1 file changed, 21 insertions(+), 138 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index f46f88620c70..83ba0c328722 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -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; - } - } + if (uptodate) + set_extent_uptodate(tree, start, end, + GFP_ATOMIC); + unlock_extent(tree, start, end, GFP_ATOMIC); - 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); -- 2.20.1