[PATCH 4.9 141/141] btrfs: set max_extent_size properly

Greg Kroah-Hartman
2018-11-11T22:35:37Z

From: Josef Bacik <jbacik@fb.com>

commit ad22cf6ea47fa20fbe11ac324a0a15c0a9a4a2a9 upstream.

We can't use entry->bytes if our entry is a bitmap entry, we need to use
entry->max_extent_size in that case. Fix up all the logic to make this
consistent.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/btrfs/free-space-cache.c | 30 ++++++++++++++++++++----------
1 file changed, 20 insertions(+), 10 deletions(-)

--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -1778,6 +1778,13 @@ static int search_bitmap(struct btrfs_fr
return -1;
}

+static inline u64 get_max_extent_size(struct btrfs_free_space *entry)
+{
+ if (entry->bitmap)
+ return entry->max_extent_size;
+ return entry->bytes;
+}
+
/* Cache the size of the max extent in bytes */
static struct btrfs_free_space *
find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
@@ -1799,8 +1806,8 @@ find_free_space(struct btrfs_free_space_
for (node = &entry->offset_index; node; node = rb_next(node)) {
entry = rb_entry(node, struct btrfs_free_space, offset_index);
if (entry->bytes < *bytes) {
- if (entry->bytes > *max_extent_size)
- *max_extent_size = entry->bytes;
+ *max_extent_size = max(get_max_extent_size(entry),
+ *max_extent_size);
continue;
}

@@ -1818,8 +1825,8 @@ find_free_space(struct btrfs_free_space_
}

if (entry->bytes < *bytes + align_off) {
- if (entry->bytes > *max_extent_size)
- *max_extent_size = entry->bytes;
+ *max_extent_size = max(get_max_extent_size(entry),
+ *max_extent_size);
continue;
}

@@ -1831,8 +1838,10 @@ find_free_space(struct btrfs_free_space_
*offset = tmp;
*bytes = size;
return entry;
- } else if (size > *max_extent_size) {
- *max_extent_size = size;
+ } else {
+ *max_extent_size =
+ max(get_max_extent_size(entry),
+ *max_extent_size);
}
continue;
}
@@ -2691,8 +2700,8 @@ static u64 btrfs_alloc_from_bitmap(struc

err = search_bitmap(ctl, entry, &search_start, &search_bytes, true);
if (err) {
- if (search_bytes > *max_extent_size)
- *max_extent_size = search_bytes;
+ *max_extent_size = max(get_max_extent_size(entry),
+ *max_extent_size);
return 0;
}

@@ -2729,8 +2738,9 @@ u64 btrfs_alloc_from_cluster(struct btrf

entry = rb_entry(node, struct btrfs_free_space, offset_index);
while (1) {
- if (entry->bytes < bytes && entry->bytes > *max_extent_size)
- *max_extent_size = entry->bytes;
+ if (entry->bytes < bytes)
+ *max_extent_size = max(get_max_extent_size(entry),
+ *max_extent_size);

if (entry->bytes < bytes ||
(!entry->bitmap && entry->offset < min_start)) {