From: Jon Derrick <jonathan.derrick@intel.com>
To: linux-block@vger.kernel.org
Cc: Jon Derrick <jonathan.derrick@intel.com>,
"Jens Axboe" <axboe@fb.com>,
"Alexander Viro" <viro@zeniv.linux.org.uk>,
linux-fsdevel@vger.kernel.org,
"Dan Williams" <dan.j.williams@intel.com>,
"Jeff Moyer" <jmoyer@redhat.com>,
"Stephen Bates" <stephen.bates@microsemi.com>,
"Keith Busch" <keith.busch@intel.com>,
"Christoph Hellwig" <hch@infradead.org>,
"Robert Elliott" <elliott@hpe.com>
Subject: [PATCH] block: Fix S_DAX inode flag locking
Date: Tue, 17 May 2016 12:29:57 -0600 [thread overview]
Message-ID: <1463509797-10324-2-git-send-email-jonathan.derrick@intel.com> (raw)
In-Reply-To: <1463509797-10324-1-git-send-email-jonathan.derrick@intel.com>
This patch fixes S_DAX bd_inode i_flag locking to conform to suggested
locking rules. It is presumed that S_DAX is the only valid inode flag
for a block device which subscribes to direct-access, and will restore
any previously set flags if direct-access initialization fails.
This reverts to i_flags behavior prior to
bbab37ddc20bae4709bca8745c128c4f46fe63c5
by allowing other bd_inode flags when DAX is disabled
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
---
fs/block_dev.c | 31 ++++++++++++++++++++++++++-----
1 file changed, 26 insertions(+), 5 deletions(-)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 20a2c02..d41e37f 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1159,6 +1159,20 @@ void bd_set_size(struct block_device *bdev, loff_t size)
}
EXPORT_SYMBOL(bd_set_size);
+static void bd_add_dax(struct inode *inode)
+{
+ inode_lock(inode);
+ inode->i_flags |= S_DAX;
+ inode_unlock(inode);
+}
+
+static void bd_clear_dax(struct inode *inode)
+{
+ inode_lock(inode);
+ inode->i_flags &= ~S_DAX;
+ inode_unlock(inode);
+}
+
static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part);
/*
@@ -1172,6 +1186,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
{
struct gendisk *disk;
struct module *owner;
+ struct inode *inode;
int ret;
int partno;
int perm = 0;
@@ -1198,6 +1213,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
if (!disk)
goto out;
owner = disk->fops->owner;
+ inode = bdev->bd_inode;
disk_block_events(disk);
mutex_lock_nested(&bdev->bd_mutex, for_part);
@@ -1206,9 +1222,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
bdev->bd_queue = disk->queue;
bdev->bd_contains = bdev;
if (IS_ENABLED(CONFIG_BLK_DEV_DAX) && disk->fops->direct_access)
- bdev->bd_inode->i_flags = S_DAX;
- else
- bdev->bd_inode->i_flags = 0;
+ bd_add_dax(inode);
if (!partno) {
ret = -ENXIO;
@@ -1228,6 +1242,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
bdev->bd_part = NULL;
bdev->bd_disk = NULL;
bdev->bd_queue = NULL;
+ bd_clear_dax(inode);
mutex_unlock(&bdev->bd_mutex);
disk_unblock_events(disk);
put_disk(disk);
@@ -1239,7 +1254,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
if (!ret) {
bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
if (!blkdev_dax_capable(bdev))
- bdev->bd_inode->i_flags &= ~S_DAX;
+ bd_clear_dax(inode);
}
/*
@@ -1276,7 +1291,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
}
bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
if (!blkdev_dax_capable(bdev))
- bdev->bd_inode->i_flags &= ~S_DAX;
+ bd_clear_dax(inode);
}
} else {
if (bdev->bd_contains == bdev) {
@@ -1297,6 +1312,11 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
put_disk(disk);
module_put(owner);
}
+ inode_lock(inode);
+ if (inode->i_flags & S_DAX)
+ inode->i_flags = S_DAX;
+ inode_unlock(inode);
+
bdev->bd_openers++;
if (for_part)
bdev->bd_part_count++;
@@ -1309,6 +1329,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
bdev->bd_disk = NULL;
bdev->bd_part = NULL;
bdev->bd_queue = NULL;
+ bd_clear_dax(inode);
if (bdev != bdev->bd_contains)
__blkdev_put(bdev->bd_contains, mode, 1);
bdev->bd_contains = NULL;
--
1.8.3.1
next prev parent reply other threads:[~2016-05-17 18:31 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-17 18:29 [PATCH] Fix S_DAX setting in __blkdev_get Jon Derrick
2016-05-17 18:29 ` Jon Derrick [this message]
2016-05-17 19:34 ` [PATCH] block: Fix S_DAX inode flag locking Dan Williams
2016-05-17 20:38 ` Jon Derrick
2016-05-18 8:29 ` Jan Kara
2016-05-17 22:58 ` Dave Chinner
2016-05-18 8:20 ` Jan Kara
2016-05-18 14:32 ` Dave Chinner
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