Revision d58b0d980f0b1c27204da0e05537b606da45a07f authored by Linus Torvalds on 04 August 2016, 23:56:16 UTC, committed by Linus Torvalds on 04 August 2016, 23:56:16 UTC
Pull more btrfs updates from Chris Mason: "This is part two of my btrfs pull, which is some cleanups and a batch of fixes. Most of the code here is from Jeff Mahoney, making the pointers we pass around internally more consistent and less confusing overall. I noticed a small problem right before I sent this out yesterday, so I fixed it up and re-tested overnight" * 'for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (40 commits) Btrfs: fix __MAX_CSUM_ITEMS btrfs: btrfs_abort_transaction, drop root parameter btrfs: add btrfs_trans_handle->fs_info pointer btrfs: btrfs_relocate_chunk pass extent_root to btrfs_end_transaction btrfs: convert nodesize macros to static inlines btrfs: introduce BTRFS_MAX_ITEM_SIZE btrfs: cleanup, remove prototype for btrfs_find_root_ref btrfs: copy_to_sk drop unused root parameter btrfs: simpilify btrfs_subvol_inherit_props btrfs: tests, use BTRFS_FS_STATE_DUMMY_FS_INFO instead of dummy root btrfs: tests, require fs_info for root btrfs: tests, move initialization into tests/ btrfs: btrfs_test_opt and friends should take a btrfs_fs_info btrfs: prefix fsid to all trace events btrfs: plumb fs_info into btrfs_work btrfs: remove obsolete part of comment in statfs btrfs: hide test-only member under ifdef btrfs: Ratelimit "no csum found" info message btrfs: Add ratelimit to btrfs printing Btrfs: fix unexpected balance crash due to BUG_ON ...
once.c
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/once.h>
#include <linux/random.h>
struct once_work {
struct work_struct work;
struct static_key *key;
};
static void once_deferred(struct work_struct *w)
{
struct once_work *work;
work = container_of(w, struct once_work, work);
BUG_ON(!static_key_enabled(work->key));
static_key_slow_dec(work->key);
kfree(work);
}
static void once_disable_jump(struct static_key *key)
{
struct once_work *w;
w = kmalloc(sizeof(*w), GFP_ATOMIC);
if (!w)
return;
INIT_WORK(&w->work, once_deferred);
w->key = key;
schedule_work(&w->work);
}
static DEFINE_SPINLOCK(once_lock);
bool __do_once_start(bool *done, unsigned long *flags)
__acquires(once_lock)
{
spin_lock_irqsave(&once_lock, *flags);
if (*done) {
spin_unlock_irqrestore(&once_lock, *flags);
/* Keep sparse happy by restoring an even lock count on
* this lock. In case we return here, we don't call into
* __do_once_done but return early in the DO_ONCE() macro.
*/
__acquire(once_lock);
return false;
}
return true;
}
EXPORT_SYMBOL(__do_once_start);
void __do_once_done(bool *done, struct static_key *once_key,
unsigned long *flags)
__releases(once_lock)
{
*done = true;
spin_unlock_irqrestore(&once_lock, *flags);
once_disable_jump(once_key);
}
EXPORT_SYMBOL(__do_once_done);
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