Btrfs: make find_first_extent_bit be able to cache any state
Right now the only caller of find_first_extent_bit() that is interested
in caching extent states (transaction or log commit), never gets an extent
state cached. This is because find_first_extent_bit() only caches states
that have at least one of the flags EXTENT_IOBITS or EXTENT_BOUNDARY, and
the transaction/log commit caller always passes a tree that doesn't have
ever extent states with any of those flags (they can only have one of the
following flags: EXTENT_DIRTY, EXTENT_NEW or EXTENT_NEED_WAIT).
This change together with the following one in the patch series (titled
"Btrfs: avoid returning -ENOMEM in convert_extent_bit() too early") will
help reduce significantly the chances of calls to convert_extent_bit()
fail with -ENOMEM when called from the transaction/log commit code.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 420fe26..0d931b1 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -796,17 +796,25 @@
state->state |= bits_to_set;
}
-static void cache_state(struct extent_state *state,
- struct extent_state **cached_ptr)
+static void cache_state_if_flags(struct extent_state *state,
+ struct extent_state **cached_ptr,
+ const u64 flags)
{
if (cached_ptr && !(*cached_ptr)) {
- if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
+ if (!flags || (state->state & flags)) {
*cached_ptr = state;
atomic_inc(&state->refs);
}
}
}
+static void cache_state(struct extent_state *state,
+ struct extent_state **cached_ptr)
+{
+ return cache_state_if_flags(state, cached_ptr,
+ EXTENT_IOBITS | EXTENT_BOUNDARY);
+}
+
/*
* set some bits on a range in the tree. This may require allocations or
* sleeping, so the gfp mask is used to indicate what is allowed.
@@ -1482,7 +1490,7 @@
state = find_first_extent_bit_state(tree, start, bits);
got_it:
if (state) {
- cache_state(state, cached_state);
+ cache_state_if_flags(state, cached_state, 0);
*start_ret = state->start;
*end_ret = state->end;
ret = 0;