return try_release_extent_state(tree, page, mask);
}
-/*
- * 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 btrfs_inode *inode,
- u64 offset, u64 last)
-{
- u64 sectorsize = btrfs_inode_sectorsize(inode);
- struct extent_map *em;
- u64 len;
-
- if (offset >= last)
- return NULL;
-
- while (1) {
- len = last - offset;
- if (len == 0)
- break;
- len = ALIGN(len, sectorsize);
- em = btrfs_get_extent_fiemap(inode, offset, len);
- if (IS_ERR(em))
- return em;
-
- /* if this isn't a hole return it */
- if (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;
-}
-
/*
* To cache previous fiemap extent
*
{
int ret = 0;
+ /* Set at the end of extent_fiemap(). */
+ ASSERT((flags & FIEMAP_EXTENT_LAST) == 0);
+
if (!cache->cached)
goto assign;
* So truly compressed (physical size smaller than logical size)
* extents won't get merged with each other
*
- * 3) Share same flags except FIEMAP_EXTENT_LAST
- * So regular extent won't get merged with prealloc extent
+ * 3) Share same flags
*/
if (cache->offset + cache->len == offset &&
cache->phys + cache->len == phys &&
- (cache->flags & ~FIEMAP_EXTENT_LAST) ==
- (flags & ~FIEMAP_EXTENT_LAST)) {
+ cache->flags == flags) {
cache->len += len;
- cache->flags |= flags;
- goto try_submit_last;
+ return 0;
}
/* Not mergeable, need to submit cached one */
cache->phys = phys;
cache->len = len;
cache->flags = flags;
-try_submit_last:
- if (cache->flags & FIEMAP_EXTENT_LAST) {
- ret = fiemap_fill_next_extent(fieinfo, cache->offset,
- cache->phys, cache->len, cache->flags);
- cache->cached = false;
- }
- return ret;
+
+ return 0;
}
/*
return ret;
}
-int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
- u64 start, u64 len)
+static int fiemap_next_leaf_item(struct btrfs_inode *inode, struct btrfs_path *path)
{
- int ret = 0;
- u64 off;
- u64 max = start + len;
- u32 flags = 0;
- u32 found_type;
- u64 last;
- u64 last_for_get_extent = 0;
- u64 disko = 0;
- u64 isize = i_size_read(&inode->vfs_inode);
- struct btrfs_key found_key;
- struct extent_map *em = NULL;
- struct extent_state *cached_state = NULL;
- struct btrfs_path *path;
+ struct extent_buffer *clone;
+ struct btrfs_key key;
+ int slot;
+ int ret;
+
+ path->slots[0]++;
+ if (path->slots[0] < btrfs_header_nritems(path->nodes[0]))
+ return 0;
+
+ ret = btrfs_next_leaf(inode->root, path);
+ if (ret != 0)
+ return ret;
+
+ /*
+ * Don't bother with cloning if there are no more file extent items for
+ * our inode.
+ */
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+ if (key.objectid != btrfs_ino(inode) || key.type != BTRFS_EXTENT_DATA_KEY)
+ return 1;
+
+ /* See the comment at fiemap_search_slot() about why we clone. */
+ clone = btrfs_clone_extent_buffer(path->nodes[0]);
+ if (!clone)
+ return -ENOMEM;
+
+ slot = path->slots[0];
+ btrfs_release_path(path);
+ path->nodes[0] = clone;
+ path->slots[0] = slot;
+
+ return 0;
+}
+
+/*
+ * Search for the first file extent item that starts at a given file offset or
+ * the one that starts immediately before that offset.
+ * Returns: 0 on success, < 0 on error, 1 if not found.
+ */
+static int fiemap_search_slot(struct btrfs_inode *inode, struct btrfs_path *path,
+ u64 file_offset)
+{
+ const u64 ino = btrfs_ino(inode);
struct btrfs_root *root = inode->root;
- struct fiemap_cache cache = { 0 };
- struct btrfs_backref_shared_cache *backref_cache;
- struct ulist *roots;
- struct ulist *tmp_ulist;
- int end = 0;
- u64 em_start = 0;
- u64 em_len = 0;
- u64 em_end = 0;
+ struct extent_buffer *clone;
+ struct btrfs_key key;
+ int slot;
+ int ret;
- backref_cache = kzalloc(sizeof(*backref_cache), GFP_KERNEL);
- path = btrfs_alloc_path();
- roots = ulist_alloc(GFP_KERNEL);
- tmp_ulist = ulist_alloc(GFP_KERNEL);
- if (!backref_cache || !path || !roots || !tmp_ulist) {
- ret = -ENOMEM;
- goto out_free_ulist;
+ key.objectid = ino;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = file_offset;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ return ret;
+
+ if (ret > 0 && path->slots[0] > 0) {
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0] - 1);
+ if (key.objectid == ino && key.type == BTRFS_EXTENT_DATA_KEY)
+ path->slots[0]--;
+ }
+
+ if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret != 0)
+ return ret;
+
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+ if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY)
+ return 1;
}
/*
- * We can't initialize that to 'start' as this could miss extents due
- * to extent item merging
+ * We clone the leaf and use it during fiemap. This is because while
+ * using the leaf we do expensive things like checking if an extent is
+ * shared, which can take a long time. In order to prevent blocking
+ * other tasks for too long, we use a clone of the leaf. We have locked
+ * the file range in the inode's io tree, so we know none of our file
+ * extent items can change. This way we avoid blocking other tasks that
+ * want to insert items for other inodes in the same leaf or b+tree
+ * rebalance operations (triggered for example when someone is trying
+ * to push items into this leaf when trying to insert an item in a
+ * neighbour leaf).
+ * We also need the private clone because holding a read lock on an
+ * extent buffer of the subvolume's b+tree will make lockdep unhappy
+ * when we call fiemap_fill_next_extent(), because that may cause a page
+ * fault when filling the user space buffer with fiemap data.
*/
- off = 0;
- start = round_down(start, btrfs_inode_sectorsize(inode));
- len = round_up(max, btrfs_inode_sectorsize(inode)) - start;
+ clone = btrfs_clone_extent_buffer(path->nodes[0]);
+ if (!clone)
+ return -ENOMEM;
+
+ slot = path->slots[0];
+ btrfs_release_path(path);
+ path->nodes[0] = clone;
+ path->slots[0] = slot;
+
+ return 0;
+}
+
+/*
+ * Process a range which is a hole or a prealloc extent in the inode's subvolume
+ * btree. If @disk_bytenr is 0, we are dealing with a hole, otherwise a prealloc
+ * extent. The end offset (@end) is inclusive.
+ */
+static int fiemap_process_hole(struct btrfs_inode *inode,
+ struct fiemap_extent_info *fieinfo,
+ struct fiemap_cache *cache,
+ struct btrfs_backref_shared_cache *backref_cache,
+ u64 disk_bytenr, u64 extent_offset,
+ u64 extent_gen,
+ struct ulist *roots, struct ulist *tmp_ulist,
+ u64 start, u64 end)
+{
+ const u64 i_size = i_size_read(&inode->vfs_inode);
+ const u64 ino = btrfs_ino(inode);
+ u64 cur_offset = start;
+ u64 last_delalloc_end = 0;
+ u32 prealloc_flags = FIEMAP_EXTENT_UNWRITTEN;
+ bool checked_extent_shared = false;
+ int ret;
/*
- * lookup the last file extent. We're not using i_size here
- * because there might be preallocation past i_size
+ * There can be no delalloc past i_size, so don't waste time looking for
+ * it beyond i_size.
*/
- ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode), -1,
- 0);
- if (ret < 0) {
- goto out_free_ulist;
- } else {
- WARN_ON(!ret);
- if (ret == 1)
- ret = 0;
- }
+ while (cur_offset < end && cur_offset < i_size) {
+ u64 delalloc_start;
+ u64 delalloc_end;
+ u64 prealloc_start;
+ u64 prealloc_len = 0;
+ bool delalloc;
+
+ delalloc = btrfs_find_delalloc_in_range(inode, cur_offset, end,
+ &delalloc_start,
+ &delalloc_end);
+ if (!delalloc)
+ break;
- path->slots[0]--;
- btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
- found_type = found_key.type;
-
- /* No extents, but there might be delalloc bits */
- if (found_key.objectid != btrfs_ino(inode) ||
- found_type != BTRFS_EXTENT_DATA_KEY) {
- /* 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
+ * If this is a prealloc extent we have to report every section
+ * of it that has no delalloc.
*/
- last = found_key.offset;
- last_for_get_extent = last + 1;
+ if (disk_bytenr != 0) {
+ if (last_delalloc_end == 0) {
+ prealloc_start = start;
+ prealloc_len = delalloc_start - start;
+ } else {
+ prealloc_start = last_delalloc_end + 1;
+ prealloc_len = delalloc_start - prealloc_start;
+ }
+ }
+
+ if (prealloc_len > 0) {
+ if (!checked_extent_shared && fieinfo->fi_extents_max) {
+ ret = btrfs_is_data_extent_shared(inode->root,
+ ino, disk_bytenr,
+ extent_gen, roots,
+ tmp_ulist,
+ backref_cache);
+ if (ret < 0)
+ return ret;
+ else if (ret > 0)
+ prealloc_flags |= FIEMAP_EXTENT_SHARED;
+
+ checked_extent_shared = true;
+ }
+ ret = emit_fiemap_extent(fieinfo, cache, prealloc_start,
+ disk_bytenr + extent_offset,
+ prealloc_len, prealloc_flags);
+ if (ret)
+ return ret;
+ extent_offset += prealloc_len;
+ }
+
+ ret = emit_fiemap_extent(fieinfo, cache, delalloc_start, 0,
+ delalloc_end + 1 - delalloc_start,
+ FIEMAP_EXTENT_DELALLOC |
+ FIEMAP_EXTENT_UNKNOWN);
+ if (ret)
+ return ret;
+
+ last_delalloc_end = delalloc_end;
+ cur_offset = delalloc_end + 1;
+ extent_offset += cur_offset - delalloc_start;
+ cond_resched();
+ }
+
+ /*
+ * Either we found no delalloc for the whole prealloc extent or we have
+ * a prealloc extent that spans i_size or starts at or after i_size.
+ */
+ if (disk_bytenr != 0 && last_delalloc_end < end) {
+ u64 prealloc_start;
+ u64 prealloc_len;
+
+ if (last_delalloc_end == 0) {
+ prealloc_start = start;
+ prealloc_len = end + 1 - start;
+ } else {
+ prealloc_start = last_delalloc_end + 1;
+ prealloc_len = end + 1 - prealloc_start;
+ }
+
+ if (!checked_extent_shared && fieinfo->fi_extents_max) {
+ ret = btrfs_is_data_extent_shared(inode->root,
+ ino, disk_bytenr,
+ extent_gen, roots,
+ tmp_ulist,
+ backref_cache);
+ if (ret < 0)
+ return ret;
+ else if (ret > 0)
+ prealloc_flags |= FIEMAP_EXTENT_SHARED;
+ }
+ ret = emit_fiemap_extent(fieinfo, cache, prealloc_start,
+ disk_bytenr + extent_offset,
+ prealloc_len, prealloc_flags);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int fiemap_find_last_extent_offset(struct btrfs_inode *inode,
+ struct btrfs_path *path,
+ u64 *last_extent_end_ret)
+{
+ const u64 ino = btrfs_ino(inode);
+ struct btrfs_root *root = inode->root;
+ struct extent_buffer *leaf;
+ struct btrfs_file_extent_item *ei;
+ struct btrfs_key key;
+ u64 disk_bytenr;
+ int ret;
+
+ /*
+ * 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, root, path, ino, (u64)-1, 0);
+ /* There can't be a file extent item at offset (u64)-1 */
+ ASSERT(ret != 0);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * For a non-existing key, btrfs_search_slot() always leaves us at a
+ * slot > 0, except if the btree is empty, which is impossible because
+ * at least it has the inode item for this inode and all the items for
+ * the root inode 256.
+ */
+ ASSERT(path->slots[0] > 0);
+ path->slots[0]--;
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY) {
+ /* No file extent items in the subvolume tree. */
+ *last_extent_end_ret = 0;
+ return 0;
}
- btrfs_release_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
+ * For an inline extent, the disk_bytenr is where inline data starts at,
+ * so first check if we have an inline extent item before checking if we
+ * have an implicit hole (disk_bytenr == 0).
*/
- if (last < isize) {
- last = (u64)-1;
- last_for_get_extent = isize;
+ ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item);
+ if (btrfs_file_extent_type(leaf, ei) == BTRFS_FILE_EXTENT_INLINE) {
+ *last_extent_end_ret = btrfs_file_extent_end(path);
+ return 0;
}
- lock_extent_bits(&inode->io_tree, start, start + len - 1,
- &cached_state);
+ /*
+ * Find the last file extent item that is not a hole (when NO_HOLES is
+ * not enabled). This should take at most 2 iterations in the worst
+ * case: we have one hole file extent item at slot 0 of a leaf and
+ * another hole file extent item as the last item in the previous leaf.
+ * This is because we merge file extent items that represent holes.
+ */
+ disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, ei);
+ while (disk_bytenr == 0) {
+ ret = btrfs_previous_item(root, path, ino, BTRFS_EXTENT_DATA_KEY);
+ if (ret < 0) {
+ return ret;
+ } else if (ret > 0) {
+ /* No file extent items that are not holes. */
+ *last_extent_end_ret = 0;
+ return 0;
+ }
+ leaf = path->nodes[0];
+ ei = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, ei);
+ }
- em = get_extent_skip_holes(inode, start, last_for_get_extent);
- if (!em)
- goto out;
- if (IS_ERR(em)) {
- ret = PTR_ERR(em);
+ *last_extent_end_ret = btrfs_file_extent_end(path);
+ return 0;
+}
+
+int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
+ u64 start, u64 len)
+{
+ const u64 ino = btrfs_ino(inode);
+ struct extent_state *cached_state = NULL;
+ struct btrfs_path *path;
+ struct btrfs_root *root = inode->root;
+ struct fiemap_cache cache = { 0 };
+ struct btrfs_backref_shared_cache *backref_cache;
+ struct ulist *roots;
+ struct ulist *tmp_ulist;
+ u64 last_extent_end;
+ u64 prev_extent_end;
+ u64 lockstart;
+ u64 lockend;
+ bool stopped = false;
+ int ret;
+
+ backref_cache = kzalloc(sizeof(*backref_cache), GFP_KERNEL);
+ path = btrfs_alloc_path();
+ roots = ulist_alloc(GFP_KERNEL);
+ tmp_ulist = ulist_alloc(GFP_KERNEL);
+ if (!backref_cache || !path || !roots || !tmp_ulist) {
+ ret = -ENOMEM;
goto out;
}
- while (!end) {
- u64 offset_in_extent = 0;
+ lockstart = round_down(start, btrfs_inode_sectorsize(inode));
+ lockend = round_up(start + len, btrfs_inode_sectorsize(inode));
+ prev_extent_end = lockstart;
- /* break if the extent we found is outside the range */
- if (em->start >= max || extent_map_end(em) < off)
- break;
+ lock_extent_bits(&inode->io_tree, lockstart, lockend, &cached_state);
- /*
- * get_extent may return an extent that starts before our
- * requested range. We have to make sure the ranges
- * we return to fiemap always move forward and don't
- * overlap, so adjust the offsets here
- */
- em_start = max(em->start, off);
+ ret = fiemap_find_last_extent_offset(inode, path, &last_extent_end);
+ if (ret < 0)
+ goto out_unlock;
+ btrfs_release_path(path);
+ path->reada = READA_FORWARD;
+ ret = fiemap_search_slot(inode, path, lockstart);
+ if (ret < 0) {
+ goto out_unlock;
+ } else if (ret > 0) {
/*
- * record the offset from the start of the extent
- * for adjusting the disk offset below. Only do this if the
- * extent isn't compressed since our in ram offset may be past
- * what we have actually allocated on disk.
+ * No file extent item found, but we may have delalloc between
+ * the current offset and i_size. So check for that.
*/
- if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
- offset_in_extent = em_start - em->start;
- em_end = extent_map_end(em);
- em_len = em_end - em_start;
- flags = 0;
- if (em->block_start < EXTENT_MAP_LAST_BYTE)
- disko = em->block_start + offset_in_extent;
- else
- disko = 0;
+ ret = 0;
+ goto check_eof_delalloc;
+ }
+
+ while (prev_extent_end < lockend) {
+ struct extent_buffer *leaf = path->nodes[0];
+ struct btrfs_file_extent_item *ei;
+ struct btrfs_key key;
+ u64 extent_end;
+ u64 extent_len;
+ u64 extent_offset = 0;
+ u64 extent_gen;
+ u64 disk_bytenr = 0;
+ u64 flags = 0;
+ int extent_type;
+ u8 compression;
+
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY)
+ break;
+
+ extent_end = btrfs_file_extent_end(path);
/*
- * bump off for our next call to get_extent
+ * The first iteration can leave us at an extent item that ends
+ * before our range's start. Move to the next item.
*/
- off = extent_map_end(em);
- if (off >= max)
- end = 1;
-
- if (em->block_start == EXTENT_MAP_INLINE) {
- flags |= (FIEMAP_EXTENT_DATA_INLINE |
- FIEMAP_EXTENT_NOT_ALIGNED);
- } else if (em->block_start == EXTENT_MAP_DELALLOC) {
- flags |= (FIEMAP_EXTENT_DELALLOC |
- FIEMAP_EXTENT_UNKNOWN);
- } else if (fieinfo->fi_extents_max) {
- u64 extent_gen;
- u64 bytenr = em->block_start -
- (em->start - em->orig_start);
+ if (extent_end <= lockstart)
+ goto next_item;
- /*
- * If two extent maps are merged, then their generation
- * is set to the maximum between their generations.
- * Otherwise its generation matches the one we have in
- * corresponding file extent item. If we have a merged
- * extent map, don't use its generation to speedup the
- * sharedness check below.
- */
- if (test_bit(EXTENT_FLAG_MERGED, &em->flags))
- extent_gen = 0;
- else
- extent_gen = em->generation;
+ /* We have in implicit hole (NO_HOLES feature enabled). */
+ if (prev_extent_end < key.offset) {
+ const u64 range_end = min(key.offset, lockend) - 1;
- /*
- * As btrfs supports shared space, this information
- * can be exported to userspace tools via
- * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0
- * then we're just getting a count and we can skip the
- * lookup stuff.
- */
- ret = btrfs_is_data_extent_shared(root, btrfs_ino(inode),
- bytenr, extent_gen,
- roots, tmp_ulist,
- backref_cache);
- if (ret < 0)
- goto out_free;
- if (ret)
- flags |= FIEMAP_EXTENT_SHARED;
- ret = 0;
- }
- if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
- flags |= FIEMAP_EXTENT_ENCODED;
- if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
- flags |= FIEMAP_EXTENT_UNWRITTEN;
+ ret = fiemap_process_hole(inode, fieinfo, &cache,
+ backref_cache, 0, 0, 0,
+ roots, tmp_ulist,
+ prev_extent_end, range_end);
+ if (ret < 0) {
+ goto out_unlock;
+ } else if (ret > 0) {
+ /* fiemap_fill_next_extent() told us to stop. */
+ stopped = true;
+ break;
+ }
- free_extent_map(em);
- em = NULL;
- if ((em_start >= last) || em_len == (u64)-1 ||
- (last == (u64)-1 && isize <= em_end)) {
- flags |= FIEMAP_EXTENT_LAST;
- end = 1;
+ /* We've reached the end of the fiemap range, stop. */
+ if (key.offset >= lockend) {
+ stopped = true;
+ break;
+ }
}
- /* now scan forward to see if this is really the last extent. */
- em = get_extent_skip_holes(inode, off, last_for_get_extent);
- if (IS_ERR(em)) {
- ret = PTR_ERR(em);
- goto out;
+ extent_len = extent_end - key.offset;
+ ei = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ compression = btrfs_file_extent_compression(leaf, ei);
+ extent_type = btrfs_file_extent_type(leaf, ei);
+ extent_gen = btrfs_file_extent_generation(leaf, ei);
+
+ if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
+ disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, ei);
+ if (compression == BTRFS_COMPRESS_NONE)
+ extent_offset = btrfs_file_extent_offset(leaf, ei);
}
- if (!em) {
- flags |= FIEMAP_EXTENT_LAST;
- end = 1;
+
+ if (compression != BTRFS_COMPRESS_NONE)
+ flags |= FIEMAP_EXTENT_ENCODED;
+
+ if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
+ flags |= FIEMAP_EXTENT_DATA_INLINE;
+ flags |= FIEMAP_EXTENT_NOT_ALIGNED;
+ ret = emit_fiemap_extent(fieinfo, &cache, key.offset, 0,
+ extent_len, flags);
+ } else if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ ret = fiemap_process_hole(inode, fieinfo, &cache,
+ backref_cache,
+ disk_bytenr, extent_offset,
+ extent_gen, roots, tmp_ulist,
+ key.offset, extent_end - 1);
+ } else if (disk_bytenr == 0) {
+ /* We have an explicit hole. */
+ ret = fiemap_process_hole(inode, fieinfo, &cache,
+ backref_cache, 0, 0, 0,
+ roots, tmp_ulist,
+ key.offset, extent_end - 1);
+ } else {
+ /* We have a regular extent. */
+ if (fieinfo->fi_extents_max) {
+ ret = btrfs_is_data_extent_shared(root, ino,
+ disk_bytenr,
+ extent_gen,
+ roots,
+ tmp_ulist,
+ backref_cache);
+ if (ret < 0)
+ goto out_unlock;
+ else if (ret > 0)
+ flags |= FIEMAP_EXTENT_SHARED;
+ }
+
+ ret = emit_fiemap_extent(fieinfo, &cache, key.offset,
+ disk_bytenr + extent_offset,
+ extent_len, flags);
}
- ret = emit_fiemap_extent(fieinfo, &cache, em_start, disko,
- em_len, flags);
- if (ret) {
- if (ret == 1)
- ret = 0;
- goto out_free;
+
+ if (ret < 0) {
+ goto out_unlock;
+ } else if (ret > 0) {
+ /* fiemap_fill_next_extent() told us to stop. */
+ stopped = true;
+ break;
}
+ prev_extent_end = extent_end;
+next_item:
if (fatal_signal_pending(current)) {
ret = -EINTR;
- goto out_free;
+ goto out_unlock;
}
+
+ ret = fiemap_next_leaf_item(inode, path);
+ if (ret < 0) {
+ goto out_unlock;
+ } else if (ret > 0) {
+ /* No more file extent items for this inode. */
+ break;
+ }
+ cond_resched();
}
-out_free:
- if (!ret)
- ret = emit_last_fiemap_cache(fieinfo, &cache);
- free_extent_map(em);
-out:
- unlock_extent_cached(&inode->io_tree, start, start + len - 1,
- &cached_state);
-out_free_ulist:
+check_eof_delalloc:
+ /*
+ * Release (and free) the path before emitting any final entries to
+ * fiemap_fill_next_extent() to keep lockdep happy. This is because
+ * once we find no more file extent items exist, we may have a
+ * non-cloned leaf, and fiemap_fill_next_extent() can trigger page
+ * faults when copying data to the user space buffer.
+ */
+ btrfs_free_path(path);
+ path = NULL;
+
+ if (!stopped && prev_extent_end < lockend) {
+ ret = fiemap_process_hole(inode, fieinfo, &cache, backref_cache,
+ 0, 0, 0, roots, tmp_ulist,
+ prev_extent_end, lockend - 1);
+ if (ret < 0)
+ goto out_unlock;
+ prev_extent_end = lockend;
+ }
+
+ if (cache.cached && cache.offset + cache.len >= last_extent_end) {
+ const u64 i_size = i_size_read(&inode->vfs_inode);
+
+ if (prev_extent_end < i_size) {
+ u64 delalloc_start;
+ u64 delalloc_end;
+ bool delalloc;
+
+ delalloc = btrfs_find_delalloc_in_range(inode,
+ prev_extent_end,
+ i_size - 1,
+ &delalloc_start,
+ &delalloc_end);
+ if (!delalloc)
+ cache.flags |= FIEMAP_EXTENT_LAST;
+ } else {
+ cache.flags |= FIEMAP_EXTENT_LAST;
+ }
+ }
+
+ ret = emit_last_fiemap_cache(fieinfo, &cache);
+
+out_unlock:
+ unlock_extent_cached(&inode->io_tree, lockstart, lockend, &cached_state);
+out:
kfree(backref_cache);
btrfs_free_path(path);
ulist_free(roots);
projects / linux.git / commitdiff