1 files changed, 127 insertions, 2 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index bcc461a9695f..0efdb65953c5 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -644,6 +644,7 @@ retry:
                                         async_extent->ram_size - 1, 0);
 
                 em = alloc_extent_map(GFP_NOFS);
+                BUG_ON(!em);
                 em->start = async_extent->start;
                 em->len = async_extent->ram_size;
                 em->orig_start = em->start;
@@ -820,6 +821,7 @@ static noinline int cow_file_range(struct inode *inode,
                 BUG_ON(ret);
 
                 em = alloc_extent_map(GFP_NOFS);
+                BUG_ON(!em);
                 em->start = start;
                 em->orig_start = em->start;
                 ram_size = ins.offset;
@@ -1169,6 +1171,7 @@ out_check:
                         struct extent_map_tree *em_tree;
                         em_tree = &BTRFS_I(inode)->extent_tree;
                         em = alloc_extent_map(GFP_NOFS);
+                        BUG_ON(!em);
                         em->start = cur_offset;
                         em->orig_start = em->start;
                         em->len = num_bytes;
@@ -1910,7 +1913,7 @@ static int btrfs_clean_io_failures(struct inode *inode, u64 start)
 
         private = 0;
         if (count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
-                             (u64)-1, 1, EXTENT_DIRTY)) {
+                             (u64)-1, 1, EXTENT_DIRTY, 0)) {
                 ret = get_state_private(&BTRFS_I(inode)->io_failure_tree,
                                         start, &private_failure);
                 if (ret == 0) {
@@ -5277,6 +5280,128 @@ out:
         return em;
 }
 
+struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
+                                           size_t pg_offset, u64 start, u64 len,
+                                           int create)
+{
+        struct extent_map *em;
+        struct extent_map *hole_em = NULL;
+        u64 range_start = start;
+        u64 end;
+        u64 found;
+        u64 found_end;
+        int err = 0;
+
+        em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
+        if (IS_ERR(em))
+                return em;
+        if (em) {
+                /*
+                 * if our em maps to a hole, there might
+                 * actually be delalloc bytes behind it
+                 */
+                if (em->block_start != EXTENT_MAP_HOLE)
+                        return em;
+                else
+                        hole_em = em;
+        }
+
+        /* check to see if we've wrapped (len == -1 or similar) */
+        end = start + len;
+        if (end < start)
+                end = (u64)-1;
+        else
+                end -= 1;
+
+        em = NULL;
+
+        /* ok, we didn't find anything, lets look for delalloc */
+        found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
+                                 end, len, EXTENT_DELALLOC, 1);
+        found_end = range_start + found;
+        if (found_end < range_start)
+                found_end = (u64)-1;
+
+        /*
+         * we didn't find anything useful, return
+         * the original results from get_extent()
+         */
+        if (range_start > end || found_end <= start) {
+                em = hole_em;
+                hole_em = NULL;
+                goto out;
+        }
+
+        /* adjust the range_start to make sure it doesn't
+         * go backwards from the start they passed in
+         */
+        range_start = max(start,range_start);
+        found = found_end - range_start;
+
+        if (found > 0) {
+                u64 hole_start = start;
+                u64 hole_len = len;
+
+                em = alloc_extent_map(GFP_NOFS);
+                if (!em) {
+                        err = -ENOMEM;
+                        goto out;
+                }
+                /*
+                 * when btrfs_get_extent can't find anything it
+                 * returns one huge hole
+                 *
+                 * make sure what it found really fits our range, and
+                 * adjust to make sure it is based on the start from
+                 * the caller
+                 */
+                if (hole_em) {
+                        u64 calc_end = extent_map_end(hole_em);
+
+                        if (calc_end <= start || (hole_em->start > end)) {
+                                free_extent_map(hole_em);
+                                hole_em = NULL;
+                        } else {
+                                hole_start = max(hole_em->start, start);
+                                hole_len = calc_end - hole_start;
+                        }
+                }
+                em->bdev = NULL;
+                if (hole_em && range_start > hole_start) {
+                        /* our hole starts before our delalloc, so we
+                         * have to return just the parts of the hole
+                         * that go until  the delalloc starts
+                         */
+                        em->len = min(hole_len,
+                                      range_start - hole_start);
+                        em->start = hole_start;
+                        em->orig_start = hole_start;
+                        /*
+                         * don't adjust block start at all,
+                         * it is fixed at EXTENT_MAP_HOLE
+                         */
+                        em->block_start = hole_em->block_start;
+                        em->block_len = hole_len;
+                } else {
+                        em->start = range_start;
+                        em->len = found;
+                        em->orig_start = range_start;
+                        em->block_start = EXTENT_MAP_DELALLOC;
+                        em->block_len = found;
+                }
+        } else if (hole_em) {
+                return hole_em;
+        }
+out:
+
+        free_extent_map(hole_em);
+        if (err) {
+                free_extent_map(em);
+                return ERR_PTR(err);
+        }
+        return em;
+}
+
 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
                                                   u64 start, u64 len)
 {
@@ -6099,7 +6224,7 @@ out:
 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
                 __u64 start, __u64 len)
 {
-        return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent);
+        return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
 }
 
 int btrfs_readpage(struct file *file, struct page *page)