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 <David.Woodhouse@intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index f46f88620c709415acd1c4d64fe21bf58a3aa57a..83ba0c328722c8e1feaa5118f4b87ccfa5b97462 100644 (file)
--- 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);