Commit fd7ba1c1 authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba

btrfs: add nesting tags to the locking helpers

We will need these when we switch to an rwsem, so plumb in the
infrastructure here to use later on.  I violate the 80 character limit
some here because it'll be cleaned up later.
Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 51899412
...@@ -2875,7 +2875,8 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, ...@@ -2875,7 +2875,8 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
} else { } else {
if (!btrfs_tree_read_lock_atomic(b)) { if (!btrfs_tree_read_lock_atomic(b)) {
btrfs_set_path_blocking(p); btrfs_set_path_blocking(p);
__btrfs_tree_read_lock(b, p->recurse); __btrfs_tree_read_lock(b, BTRFS_NESTING_NORMAL,
p->recurse);
} }
p->locks[level] = BTRFS_READ_LOCK; p->locks[level] = BTRFS_READ_LOCK;
} }
...@@ -5453,7 +5454,9 @@ int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, ...@@ -5453,7 +5454,9 @@ int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
} }
if (!ret) { if (!ret) {
btrfs_set_path_blocking(path); btrfs_set_path_blocking(path);
__btrfs_tree_read_lock(next, path->recurse); __btrfs_tree_read_lock(next,
BTRFS_NESTING_NORMAL,
path->recurse);
} }
next_rw_lock = BTRFS_READ_LOCK; next_rw_lock = BTRFS_READ_LOCK;
} }
...@@ -5488,7 +5491,9 @@ int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, ...@@ -5488,7 +5491,9 @@ int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
ret = btrfs_try_tree_read_lock(next); ret = btrfs_try_tree_read_lock(next);
if (!ret) { if (!ret) {
btrfs_set_path_blocking(path); btrfs_set_path_blocking(path);
__btrfs_tree_read_lock(next, path->recurse); __btrfs_tree_read_lock(next,
BTRFS_NESTING_NORMAL,
path->recurse);
} }
next_rw_lock = BTRFS_READ_LOCK; next_rw_lock = BTRFS_READ_LOCK;
} }
......
...@@ -244,7 +244,8 @@ void btrfs_set_lock_blocking_write(struct extent_buffer *eb) ...@@ -244,7 +244,8 @@ void btrfs_set_lock_blocking_write(struct extent_buffer *eb)
* *
* The rwlock is held upon exit. * The rwlock is held upon exit.
*/ */
void __btrfs_tree_read_lock(struct extent_buffer *eb, bool recurse) void __btrfs_tree_read_lock(struct extent_buffer *eb, enum btrfs_lock_nesting nest,
bool recurse)
{ {
u64 start_ns = 0; u64 start_ns = 0;
...@@ -282,7 +283,7 @@ void __btrfs_tree_read_lock(struct extent_buffer *eb, bool recurse) ...@@ -282,7 +283,7 @@ void __btrfs_tree_read_lock(struct extent_buffer *eb, bool recurse)
void btrfs_tree_read_lock(struct extent_buffer *eb) void btrfs_tree_read_lock(struct extent_buffer *eb)
{ {
__btrfs_tree_read_lock(eb, false); __btrfs_tree_read_lock(eb, BTRFS_NESTING_NORMAL, false);
} }
/* /*
...@@ -415,7 +416,7 @@ void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb) ...@@ -415,7 +416,7 @@ void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb)
* *
* The rwlock is held for write upon exit. * The rwlock is held for write upon exit.
*/ */
void btrfs_tree_lock(struct extent_buffer *eb) void __btrfs_tree_lock(struct extent_buffer *eb, enum btrfs_lock_nesting nest)
__acquires(&eb->lock) __acquires(&eb->lock)
{ {
u64 start_ns = 0; u64 start_ns = 0;
...@@ -440,6 +441,11 @@ void btrfs_tree_lock(struct extent_buffer *eb) ...@@ -440,6 +441,11 @@ void btrfs_tree_lock(struct extent_buffer *eb)
trace_btrfs_tree_lock(eb, start_ns); trace_btrfs_tree_lock(eb, start_ns);
} }
void btrfs_tree_lock(struct extent_buffer *eb)
{
__btrfs_tree_lock(eb, BTRFS_NESTING_NORMAL);
}
/* /*
* Release the write lock, either blocking or spinning (ie. there's no need * Release the write lock, either blocking or spinning (ie. there's no need
* for an explicit blocking unlock, like btrfs_tree_read_unlock_blocking). * for an explicit blocking unlock, like btrfs_tree_read_unlock_blocking).
...@@ -565,7 +571,7 @@ struct extent_buffer *__btrfs_read_lock_root_node(struct btrfs_root *root, ...@@ -565,7 +571,7 @@ struct extent_buffer *__btrfs_read_lock_root_node(struct btrfs_root *root,
while (1) { while (1) {
eb = btrfs_root_node(root); eb = btrfs_root_node(root);
__btrfs_tree_read_lock(eb, recurse); __btrfs_tree_read_lock(eb, BTRFS_NESTING_NORMAL, recurse);
if (eb == root->node) if (eb == root->node)
break; break;
btrfs_tree_read_unlock(eb); btrfs_tree_read_unlock(eb);
......
...@@ -16,12 +16,35 @@ ...@@ -16,12 +16,35 @@
#define BTRFS_WRITE_LOCK_BLOCKING 3 #define BTRFS_WRITE_LOCK_BLOCKING 3
#define BTRFS_READ_LOCK_BLOCKING 4 #define BTRFS_READ_LOCK_BLOCKING 4
/*
* We are limited in number of subclasses by MAX_LOCKDEP_SUBCLASSES, which at
* the time of this patch is 8, which is how many we use. Keep this in mind if
* you decide you want to add another subclass.
*/
enum btrfs_lock_nesting {
BTRFS_NESTING_NORMAL,
/*
* We are limited to MAX_LOCKDEP_SUBLCLASSES number of subclasses, so
* add this in here and add a static_assert to keep us from going over
* the limit. As of this writing we're limited to 8, and we're
* definitely using 8, hence this check to keep us from messing up in
* the future.
*/
BTRFS_NESTING_MAX,
};
static_assert(BTRFS_NESTING_MAX <= MAX_LOCKDEP_SUBCLASSES,
"too many lock subclasses defined");
struct btrfs_path; struct btrfs_path;
void __btrfs_tree_lock(struct extent_buffer *eb, enum btrfs_lock_nesting nest);
void btrfs_tree_lock(struct extent_buffer *eb); void btrfs_tree_lock(struct extent_buffer *eb);
void btrfs_tree_unlock(struct extent_buffer *eb); void btrfs_tree_unlock(struct extent_buffer *eb);
void __btrfs_tree_read_lock(struct extent_buffer *eb, bool recurse); void __btrfs_tree_read_lock(struct extent_buffer *eb, enum btrfs_lock_nesting nest,
bool recurse);
void btrfs_tree_read_lock(struct extent_buffer *eb); void btrfs_tree_read_lock(struct extent_buffer *eb);
void btrfs_tree_read_unlock(struct extent_buffer *eb); void btrfs_tree_read_unlock(struct extent_buffer *eb);
void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb); void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb);
......
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