From: willy@linux.intel.com (Matthew Wilcox)
Subject: [PATCH] block: Fix dev_t liftime allocations
Date: Tue, 26 Aug 2014 08:32:42 -0400 [thread overview]
Message-ID: <20140826123242.GC3285@linux.intel.com> (raw)
In-Reply-To: <1408999975-9976-1-git-send-email-keith.busch@intel.com>
On Mon, Aug 25, 2014@02:52:55PM -0600, Keith Busch wrote:
> Since the partition's release may be invoked from call_rcu's soft-irq
> context, the ext_dev_idr's mutex had to be replaced with a spinlock so
> as not so sleep.
> @@ -420,9 +420,9 @@ int blk_alloc_devt(struct hd_struct *part, dev_t *devt)
> }
>
> /* allocate ext devt */
> - mutex_lock(&ext_devt_mutex);
> + spin_lock(&ext_devt_lock);
> idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_KERNEL);
> - mutex_unlock(&ext_devt_mutex);
> + spin_unlock(&ext_devt_lock);
Can't use GFP_KERNEL if we're protected with a spinlock. See the comment
in lib/idr.c about idr_preload:
+ idr_preload(GFP_KERNEL);
- mutex_lock(&ext_devt_mutex);
+ spin_lock(&ext_devt_lock);
- idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_KERNEL);
+ idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_NOWAIT);
- mutex_unlock(&ext_devt_mutex);
+ spin_unlock(&ext_devt_lock);
WARNING: multiple messages have this Message-ID (diff)
From: Matthew Wilcox <willy@linux.intel.com>
To: Keith Busch <keith.busch@intel.com>
Cc: linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org,
axboe@kernel.dk
Subject: Re: [PATCH] block: Fix dev_t liftime allocations
Date: Tue, 26 Aug 2014 08:32:42 -0400 [thread overview]
Message-ID: <20140826123242.GC3285@linux.intel.com> (raw)
In-Reply-To: <1408999975-9976-1-git-send-email-keith.busch@intel.com>
On Mon, Aug 25, 2014 at 02:52:55PM -0600, Keith Busch wrote:
> Since the partition's release may be invoked from call_rcu's soft-irq
> context, the ext_dev_idr's mutex had to be replaced with a spinlock so
> as not so sleep.
> @@ -420,9 +420,9 @@ int blk_alloc_devt(struct hd_struct *part, dev_t *devt)
> }
>
> /* allocate ext devt */
> - mutex_lock(&ext_devt_mutex);
> + spin_lock(&ext_devt_lock);
> idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_KERNEL);
> - mutex_unlock(&ext_devt_mutex);
> + spin_unlock(&ext_devt_lock);
Can't use GFP_KERNEL if we're protected with a spinlock. See the comment
in lib/idr.c about idr_preload:
+ idr_preload(GFP_KERNEL);
- mutex_lock(&ext_devt_mutex);
+ spin_lock(&ext_devt_lock);
- idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_KERNEL);
+ idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_NOWAIT);
- mutex_unlock(&ext_devt_mutex);
+ spin_unlock(&ext_devt_lock);
next prev parent reply other threads:[~2014-08-26 12:32 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-25 20:52 [PATCH] block: Fix dev_t liftime allocations Keith Busch
2014-08-25 20:52 ` Keith Busch
2014-08-26 12:32 ` Matthew Wilcox [this message]
2014-08-26 12:32 ` Matthew Wilcox
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