From: Vishal Verma <vishal.l.verma@intel.com>
To: Dan Williams <dan.j.williams@intel.com>,
Dave Jiang <dave.jiang@intel.com>,
Alison Schofield <alison.schofield@intel.com>,
Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, nvdimm@lists.linux.dev,
linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org,
Vishal Verma <vishal.l.verma@intel.com>
Subject: [PATCH v2 4/4] dax/bus.c: Use the right locking mode (read vs write) in size_show
Date: Tue, 16 Apr 2024 15:46:19 -0600 [thread overview]
Message-ID: <20240416-vv-dax_abi_fixes-v2-4-d5f0c8ec162e@intel.com> (raw)
In-Reply-To: <20240416-vv-dax_abi_fixes-v2-0-d5f0c8ec162e@intel.com>
In size_show(), the dax_dev_rwsem only needs a read lock, but was
acquiring a write lock. Change it to down_read_interruptible() so it
doesn't unnecessarily hold a write lock.
Cc: Dan Williams <dan.j.williams@intel.com>
Fixes: c05ae9d85b47 ("dax/bus.c: replace driver-core lock usage by a local rwsem")
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
---
drivers/dax/bus.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index db183eb5ce3a..66095e60a279 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -939,11 +939,11 @@ static ssize_t size_show(struct device *dev,
unsigned long long size;
int rc;
- rc = down_write_killable(&dax_dev_rwsem);
+ rc = down_read_interruptible(&dax_dev_rwsem);
if (rc)
return rc;
size = dev_dax_size(dev_dax);
- up_write(&dax_dev_rwsem);
+ up_read(&dax_dev_rwsem);
return sysfs_emit(buf, "%llu\n", size);
}
--
2.44.0
next prev parent reply other threads:[~2024-04-16 21:46 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-16 21:46 [PATCH v2 0/4] dax/bus.c: Fixups for dax-bus locking Vishal Verma
2024-04-16 21:46 ` [PATCH v2 1/4] dax/bus.c: replace WARN_ON_ONCE() with lockdep asserts Vishal Verma
2024-04-30 1:23 ` Dan Williams
2024-04-16 21:46 ` [PATCH v2 2/4] dax/bus.c: fix locking for unregister_dax_dev / unregister_dax_mapping paths Vishal Verma
2024-04-30 1:25 ` Dan Williams
2024-04-30 4:11 ` Verma, Vishal L
2024-04-30 5:25 ` Dan Williams
2024-04-16 21:46 ` [PATCH v2 3/4] dax/bus.c: Don't use down_write_killable for non-user processes Vishal Verma
2024-04-30 1:25 ` Dan Williams
2024-04-16 21:46 ` Vishal Verma [this message]
2024-04-30 1:26 ` [PATCH v2 4/4] dax/bus.c: Use the right locking mode (read vs write) in size_show Dan Williams
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