3 files changed, 224 insertions, 42 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index e7aeba242701..ff45b80d90f0 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1433,12 +1433,13 @@ int extent_clear_unlock_delalloc(struct inode *inode,
  */
 u64 count_range_bits(struct extent_io_tree *tree,
                      u64 *start, u64 search_end, u64 max_bytes,
-                     unsigned long bits)
+                     unsigned long bits, int contig)
 {
         struct rb_node *node;
         struct extent_state *state;
         u64 cur_start = *start;
         u64 total_bytes = 0;
+        u64 last = 0;
         int found = 0;
 
         if (search_end <= cur_start) {
@@ -1463,7 +1464,9 @@ u64 count_range_bits(struct extent_io_tree *tree,
                 state = rb_entry(node, struct extent_state, rb_node);
                 if (state->start > search_end)
                         break;
-                if (state->end >= cur_start && (state->state & bits)) {
+                if (contig && found && state->start > last + 1)
+                        break;
+                if (state->end >= cur_start && (state->state & bits) == bits) {
                         total_bytes += min(search_end, state->end) + 1 -
                                        max(cur_start, state->start);
                         if (total_bytes >= max_bytes)
@@ -1472,6 +1475,9 @@ u64 count_range_bits(struct extent_io_tree *tree,
                                 *start = state->start;
                                 found = 1;
                         }
+                        last = state->end;
+                } else if (contig && found) {
+                        break;
                 }
                 node = rb_next(node);
                 if (!node)
@@ -2912,6 +2918,46 @@ out:
         return sector;
 }
 
+/*
+ * helper function for fiemap, which doesn't want to see any holes.
+ * This maps until we find something past 'last'
+ */
+static struct extent_map *get_extent_skip_holes(struct inode *inode,
+                                                u64 offset,
+                                                u64 last,
+                                                get_extent_t *get_extent)
+{
+        u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
+        struct extent_map *em;
+        u64 len;
+
+        if (offset >= last)
+                return NULL;
+
+        while(1) {
+                len = last - offset;
+                if (len == 0)
+                        break;
+                len = (len + sectorsize - 1) & ~(sectorsize - 1);
+                em = get_extent(inode, NULL, 0, offset, len, 0);
+                if (!em || IS_ERR(em))
+                        return em;
+
+                /* if this isn't a hole return it */
+                if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
+                    em->block_start != EXTENT_MAP_HOLE) {
+                        return em;
+                }
+
+                /* this is a hole, advance to the next extent */
+                offset = extent_map_end(em);
+                free_extent_map(em);
+                if (offset >= last)
+                        break;
+        }
+        return NULL;
+}
+
 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
                 __u64 start, __u64 len, get_extent_t *get_extent)
 {
@@ -2921,16 +2967,19 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
         u32 flags = 0;
         u32 found_type;
         u64 last;
+        u64 last_for_get_extent = 0;
         u64 disko = 0;
+        u64 isize = i_size_read(inode);
         struct btrfs_key found_key;
         struct extent_map *em = NULL;
         struct extent_state *cached_state = NULL;
         struct btrfs_path *path;
         struct btrfs_file_extent_item *item;
         int end = 0;
-        u64 em_start = 0, em_len = 0;
+        u64 em_start = 0;
+        u64 em_len = 0;
+        u64 em_end = 0;
         unsigned long emflags;
-        int hole = 0;
 
         if (len == 0)
                 return -EINVAL;
@@ -2940,6 +2989,10 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
                 return -ENOMEM;
         path->leave_spinning = 1;
 
+        /*
+         * lookup the last file extent.  We're not using i_size here
+         * because there might be preallocation past i_size
+         */
         ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root,
                                        path, inode->i_ino, -1, 0);
         if (ret < 0) {
@@ -2953,18 +3006,38 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
         btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
         found_type = btrfs_key_type(&found_key);
 
-        /* No extents, just return */
+        /* No extents, but there might be delalloc bits */
         if (found_key.objectid != inode->i_ino ||
             found_type != BTRFS_EXTENT_DATA_KEY) {
-                btrfs_free_path(path);
-                return 0;
+                /* have to trust i_size as the end */
+                last = (u64)-1;
+                last_for_get_extent = isize;
+        } else {
+                /*
+                 * remember the start of the last extent.  There are a
+                 * bunch of different factors that go into the length of the
+                 * extent, so its much less complex to remember where it started
+                 */
+                last = found_key.offset;
+                last_for_get_extent = last + 1;
         }
-        last = found_key.offset;
         btrfs_free_path(path);
 
+        /*
+         * we might have some extents allocated but more delalloc past those
+         * extents.  so, we trust isize unless the start of the last extent is
+         * beyond isize
+         */
+        if (last < isize) {
+                last = (u64)-1;
+                last_for_get_extent = isize;
+        }
+
         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);
+
+        em = get_extent_skip_holes(inode, off, last_for_get_extent,
+                                   get_extent);
         if (!em)
                 goto out;
         if (IS_ERR(em)) {
@@ -2973,19 +3046,14 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
         }
 
         while (!end) {
-                hole = 0;
-                off = em->start + em->len;
+                off = extent_map_end(em);
                 if (off >= max)
                         end = 1;
 
-                if (em->block_start == EXTENT_MAP_HOLE) {
-                        hole = 1;
-                        goto next;
-                }
-
                 em_start = em->start;
                 em_len = em->len;
-
+                em_end = extent_map_end(em);
+                emflags = em->flags;
                 disko = 0;
                 flags = 0;
 
@@ -3004,37 +3072,29 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
                 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
                         flags |= FIEMAP_EXTENT_ENCODED;
 
-next:
-                emflags = em->flags;
                 free_extent_map(em);
                 em = NULL;
-                if (!end) {
-                        em = get_extent(inode, NULL, 0, off, max - off, 0);
-                        if (!em)
-                                goto out;
-                        if (IS_ERR(em)) {
-                                ret = PTR_ERR(em);
-                                goto out;
-                        }
-                        emflags = em->flags;
-                }
-
-                if (test_bit(EXTENT_FLAG_VACANCY, &emflags)) {
+                if ((em_start >= last) || em_len == (u64)-1 ||
+                   (last == (u64)-1 && isize <= em_end)) {
                         flags |= FIEMAP_EXTENT_LAST;
                         end = 1;
                 }
 
-                if (em_start == last) {
+                /* now scan forward to see if this is really the last extent. */
+                em = get_extent_skip_holes(inode, off, last_for_get_extent,
+                                           get_extent);
+                if (IS_ERR(em)) {
+                        ret = PTR_ERR(em);
+                        goto out;
+                }
+                if (!em) {
                         flags |= FIEMAP_EXTENT_LAST;
                         end = 1;
                 }
-
-                if (!hole) {
-                        ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
-                                                em_len, flags);
-                        if (ret)
-                                goto out_free;
-                }
+                ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
+                                              em_len, flags);
+                if (ret)
+                        goto out_free;
         }
 out_free:
         free_extent_map(em);
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 7083cfafd061..9318dfefd59c 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -191,7 +191,7 @@ void extent_io_exit(void);
 
 u64 count_range_bits(struct extent_io_tree *tree,
                      u64 *start, u64 search_end,
-                     u64 max_bytes, unsigned long bits);
+                     u64 max_bytes, unsigned long bits, int contig);
 
 void free_extent_state(struct extent_state *state);
 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8d392ed73d57..44b926646e33 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1913,7 +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) {
@@ -5282,6 +5282,128 @@ 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)
 {
@@ -6104,7 +6226,7 @@ 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)