1 files changed, 50 insertions, 29 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 7073cbb1b2d..c99121ac5d6 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -513,7 +513,10 @@ int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
         u64 last_end;
         int err;
         int set = 0;
+        int clear = 0;
 
+        if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
+                clear = 1;
 again:
         if (!prealloc && (mask & __GFP_WAIT)) {
                 prealloc = alloc_extent_state(mask);
@@ -524,14 +527,20 @@ again:
         spin_lock(&tree->lock);
         if (cached_state) {
                 cached = *cached_state;
-                *cached_state = NULL;
-                cached_state = NULL;
+
+                if (clear) {
+                        *cached_state = NULL;
+                        cached_state = NULL;
+                }
+
                 if (cached && cached->tree && cached->start == start) {
-                        atomic_dec(&cached->refs);
+                        if (clear)
+                                atomic_dec(&cached->refs);
                         state = cached;
                         goto hit_next;
                 }
-                free_extent_state(cached);
+                if (clear)
+                        free_extent_state(cached);
         }
         /*
          * this search will find the extents that end after
@@ -946,11 +955,11 @@ int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
 }
 
 int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
-                     gfp_t mask)
+                        struct extent_state **cached_state, gfp_t mask)
 {
         return set_extent_bit(tree, start, end,
                               EXTENT_DELALLOC | EXTENT_DIRTY | EXTENT_UPTODATE,
-                              0, NULL, NULL, mask);
+                              0, NULL, cached_state, mask);
 }
 
 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
@@ -984,10 +993,11 @@ int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
 }
 
 static int clear_extent_uptodate(struct extent_io_tree *tree, u64 start,
-                                 u64 end, gfp_t mask)
+                                 u64 end, struct extent_state **cached_state,
+                                 gfp_t mask)
 {
         return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
-                                NULL, mask);
+                                cached_state, mask);
 }
 
 int wait_on_extent_writeback(struct extent_io_tree *tree, u64 start, u64 end)
@@ -1171,7 +1181,8 @@ out:
  * 1 is returned if we find something, 0 if nothing was in the tree
  */
 static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
-                                        u64 *start, u64 *end, u64 max_bytes)
+                                        u64 *start, u64 *end, u64 max_bytes,
+                                        struct extent_state **cached_state)
 {
         struct rb_node *node;
         struct extent_state *state;
@@ -1203,8 +1214,11 @@ static noinline u64 find_delalloc_range(struct extent_io_tree *tree,
                                 *end = state->end;
                         goto out;
                 }
-                if (!found)
+                if (!found) {
                         *start = state->start;
+                        *cached_state = state;
+                        atomic_inc(&state->refs);
+                }
                 found++;
                 *end = state->end;
                 cur_start = state->end + 1;
@@ -1336,10 +1350,11 @@ again:
         delalloc_start = *start;
         delalloc_end = 0;
         found = find_delalloc_range(tree, &delalloc_start, &delalloc_end,
-                                    max_bytes);
+                                    max_bytes, &cached_state);
         if (!found || delalloc_end <= *start) {
                 *start = delalloc_start;
                 *end = delalloc_end;
+                free_extent_state(cached_state);
                 return found;
         }
 
@@ -1722,7 +1737,7 @@ static void end_bio_extent_writepage(struct bio *bio, int err)
                 }
 
                 if (!uptodate) {
-                        clear_extent_uptodate(tree, start, end, GFP_NOFS);
+                        clear_extent_uptodate(tree, start, end, NULL, GFP_NOFS);
                         ClearPageUptodate(page);
                         SetPageError(page);
                 }
@@ -1750,7 +1765,8 @@ static void end_bio_extent_writepage(struct bio *bio, int err)
 static void end_bio_extent_readpage(struct bio *bio, int err)
 {
         int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
-        struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
+        struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
+        struct bio_vec *bvec = bio->bi_io_vec;
         struct extent_io_tree *tree;
         u64 start;
         u64 end;
@@ -1773,7 +1789,7 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
                 else
                         whole_page = 0;
 
-                if (--bvec >= bio->bi_io_vec)
+                if (++bvec <= bvec_end)
                         prefetchw(&bvec->bv_page->flags);
 
                 if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
@@ -1818,7 +1834,7 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
                         }
                         check_page_locked(tree, page);
                 }
-        } while (bvec >= bio->bi_io_vec);
+        } while (bvec <= bvec_end);
 
         bio_put(bio);
 }
@@ -2704,6 +2720,7 @@ int extent_readpages(struct extent_io_tree *tree,
 int extent_invalidatepage(struct extent_io_tree *tree,
                           struct page *page, unsigned long offset)
 {
+        struct extent_state *cached_state = NULL;
         u64 start = ((u64)page->index << PAGE_CACHE_SHIFT);
         u64 end = start + PAGE_CACHE_SIZE - 1;
         size_t blocksize = page->mapping->host->i_sb->s_blocksize;
@@ -2712,12 +2729,12 @@ int extent_invalidatepage(struct extent_io_tree *tree,
         if (start > end)
                 return 0;
 
-        lock_extent(tree, start, end, GFP_NOFS);
+        lock_extent_bits(tree, start, end, 0, &cached_state, GFP_NOFS);
         wait_on_page_writeback(page);
         clear_extent_bit(tree, start, end,
                          EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
                          EXTENT_DO_ACCOUNTING,
-                         1, 1, NULL, GFP_NOFS);
+                         1, 1, &cached_state, GFP_NOFS);
         return 0;
 }
 
@@ -2920,16 +2937,17 @@ sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
                 get_extent_t *get_extent)
 {
         struct inode *inode = mapping->host;
+        struct extent_state *cached_state = NULL;
         u64 start = iblock << inode->i_blkbits;
         sector_t sector = 0;
         size_t blksize = (1 << inode->i_blkbits);
         struct extent_map *em;
 
-        lock_extent(&BTRFS_I(inode)->io_tree, start, start + blksize - 1,
-                    GFP_NOFS);
+        lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + blksize - 1,
+                         0, &cached_state, GFP_NOFS);
         em = get_extent(inode, NULL, 0, start, blksize, 0);
-        unlock_extent(&BTRFS_I(inode)->io_tree, start, start + blksize - 1,
-                      GFP_NOFS);
+        unlock_extent_cached(&BTRFS_I(inode)->io_tree, start,
+                             start + blksize - 1, &cached_state, GFP_NOFS);
         if (!em || IS_ERR(em))
                 return 0;
 
@@ -2951,6 +2969,7 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
         u32 flags = 0;
         u64 disko = 0;
         struct extent_map *em = NULL;
+        struct extent_state *cached_state = NULL;
         int end = 0;
         u64 em_start = 0, em_len = 0;
         unsigned long emflags;
@@ -2959,8 +2978,8 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
         if (len == 0)
                 return -EINVAL;
 
-        lock_extent(&BTRFS_I(inode)->io_tree, start, start + len,
-                GFP_NOFS);
+        lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0,
+                         &cached_state, GFP_NOFS);
         em = get_extent(inode, NULL, 0, off, max - off, 0);
         if (!em)
                 goto out;
@@ -3023,8 +3042,8 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 out_free:
         free_extent_map(em);
 out:
-        unlock_extent(&BTRFS_I(inode)->io_tree, start, start + len,
-                        GFP_NOFS);
+        unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len,
+                             &cached_state, GFP_NOFS);
         return ret;
 }
 
@@ -3264,7 +3283,8 @@ int set_extent_buffer_dirty(struct extent_io_tree *tree,
 }
 
 int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
-                                struct extent_buffer *eb)
+                                struct extent_buffer *eb,
+                                struct extent_state **cached_state)
 {
         unsigned long i;
         struct page *page;
@@ -3274,7 +3294,7 @@ int clear_extent_buffer_uptodate(struct extent_io_tree *tree,
         clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
 
         clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
-                              GFP_NOFS);
+                              cached_state, GFP_NOFS);
         for (i = 0; i < num_pages; i++) {
                 page = extent_buffer_page(eb, i);
                 if (page)
@@ -3334,7 +3354,8 @@ int extent_range_uptodate(struct extent_io_tree *tree,
 }
 
 int extent_buffer_uptodate(struct extent_io_tree *tree,
-                           struct extent_buffer *eb)
+                           struct extent_buffer *eb,
+                           struct extent_state *cached_state)
 {
         int ret = 0;
         unsigned long num_pages;
@@ -3346,7 +3367,7 @@ int extent_buffer_uptodate(struct extent_io_tree *tree,
                 return 1;
 
         ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1,
-                           EXTENT_UPTODATE, 1, NULL);
+                           EXTENT_UPTODATE, 1, cached_state);
         if (ret)
                 return ret;