[PATCH v6 2/2] block_dev: Rename bd_fsfreeze_mutex

From: Waiman Long
Date: Mon Sep 18 2017 - 14:54:36 EST


As the bd_fsfreeze_mutex is used by the blktrace subsystem as well,
it is now renamed to bd_fsfreeze_blktrace_mutex to better reflect
its purpose.

Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
---
fs/block_dev.c | 14 +++++++-------
fs/gfs2/ops_fstype.c | 6 +++---
fs/nilfs2/super.c | 6 +++---
fs/super.c | 6 +++---
include/linux/fs.h | 5 +++--
kernel/trace/blktrace.c | 14 +++++++-------
6 files changed, 26 insertions(+), 25 deletions(-)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 93d088f..3dea006 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -504,7 +504,7 @@ struct super_block *freeze_bdev(struct block_device *bdev)
struct super_block *sb;
int error = 0;

- mutex_lock(&bdev->bd_fsfreeze_mutex);
+ mutex_lock(&bdev->bd_fsfreeze_blktrace_mutex);
if (++bdev->bd_fsfreeze_count > 1) {
/*
* We don't even need to grab a reference - the first call
@@ -514,7 +514,7 @@ struct super_block *freeze_bdev(struct block_device *bdev)
sb = get_super(bdev);
if (sb)
drop_super(sb);
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ mutex_unlock(&bdev->bd_fsfreeze_blktrace_mutex);
return sb;
}

@@ -528,13 +528,13 @@ struct super_block *freeze_bdev(struct block_device *bdev)
if (error) {
deactivate_super(sb);
bdev->bd_fsfreeze_count--;
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ mutex_unlock(&bdev->bd_fsfreeze_blktrace_mutex);
return ERR_PTR(error);
}
deactivate_super(sb);
out:
sync_blockdev(bdev);
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ mutex_unlock(&bdev->bd_fsfreeze_blktrace_mutex);
return sb; /* thaw_bdev releases s->s_umount */
}
EXPORT_SYMBOL(freeze_bdev);
@@ -550,7 +550,7 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb)
{
int error = -EINVAL;

- mutex_lock(&bdev->bd_fsfreeze_mutex);
+ mutex_lock(&bdev->bd_fsfreeze_blktrace_mutex);
if (!bdev->bd_fsfreeze_count)
goto out;

@@ -568,7 +568,7 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb)
if (error)
bdev->bd_fsfreeze_count++;
out:
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ mutex_unlock(&bdev->bd_fsfreeze_blktrace_mutex);
return error;
}
EXPORT_SYMBOL(thaw_bdev);
@@ -767,7 +767,7 @@ static void init_once(void *foo)
bdev->bd_bdi = &noop_backing_dev_info;
inode_init_once(&ei->vfs_inode);
/* Initialize mutex for freeze. */
- mutex_init(&bdev->bd_fsfreeze_mutex);
+ mutex_init(&bdev->bd_fsfreeze_blktrace_mutex);
}

static void bdev_evict_inode(struct inode *inode)
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index a3711f5..5664905 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -1269,14 +1269,14 @@ static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags,
* will protect the lockfs code from trying to start a snapshot
* while we are mounting
*/
- mutex_lock(&bdev->bd_fsfreeze_mutex);
+ mutex_lock(&bdev->bd_fsfreeze_blktrace_mutex);
if (bdev->bd_fsfreeze_count > 0) {
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ mutex_unlock(&bdev->bd_fsfreeze_blktrace_mutex);
error = -EBUSY;
goto error_bdev;
}
s = sget(fs_type, test_gfs2_super, set_gfs2_super, flags, bdev);
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ mutex_unlock(&bdev->bd_fsfreeze_blktrace_mutex);
error = PTR_ERR(s);
if (IS_ERR(s))
goto error_bdev;
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 4fc018d..931b455 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -1306,15 +1306,15 @@ static int nilfs_test_bdev_super(struct super_block *s, void *data)
* will protect the lockfs code from trying to start a snapshot
* while we are mounting
*/
- mutex_lock(&sd.bdev->bd_fsfreeze_mutex);
+ mutex_lock(&sd.bdev->bd_fsfreeze_blktrace_mutex);
if (sd.bdev->bd_fsfreeze_count > 0) {
- mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
+ mutex_unlock(&sd.bdev->bd_fsfreeze_blktrace_mutex);
err = -EBUSY;
goto failed;
}
s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, flags,
sd.bdev);
- mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);
+ mutex_unlock(&sd.bdev->bd_fsfreeze_blktrace_mutex);
if (IS_ERR(s)) {
err = PTR_ERR(s);
goto failed;
diff --git a/fs/super.c b/fs/super.c
index 166c4ee..079890f 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -1083,15 +1083,15 @@ struct dentry *mount_bdev(struct file_system_type *fs_type,
* will protect the lockfs code from trying to start a snapshot
* while we are mounting
*/
- mutex_lock(&bdev->bd_fsfreeze_mutex);
+ mutex_lock(&bdev->bd_fsfreeze_blktrace_mutex);
if (bdev->bd_fsfreeze_count > 0) {
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ mutex_unlock(&bdev->bd_fsfreeze_blktrace_mutex);
error = -EBUSY;
goto error_bdev;
}
s = sget(fs_type, test_bdev_super, set_bdev_super, flags | SB_NOSEC,
bdev);
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ mutex_unlock(&bdev->bd_fsfreeze_blktrace_mutex);
if (IS_ERR(s))
goto error_s;

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 330b572..16c4297 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -448,8 +448,9 @@ struct block_device {

/* The counter of freeze processes */
int bd_fsfreeze_count;
- /* Mutex for freeze and blktrace */
- struct mutex bd_fsfreeze_mutex;
+
+ /* Mutex for both freeze and blktrace */
+ struct mutex bd_fsfreeze_blktrace_mutex;
} __randomize_layout;

/*
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 7cd5d1d..463a470 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -656,7 +656,7 @@ int blk_trace_startstop(struct request_queue *q, int start)
* Protection from multiple readers and writers accessing blktrace data
* concurrently is still required. The bd_mutex was used for this purpose.
* That could lead to deadlock with concurrent block device deletion and
- * sysfs access. Instead, the block device bd_fsfreeze_mutex is now
+ * sysfs access. Instead, the block device bd_fsfreeze_blktrace_mutex is now
* overloaded for blktrace data protection. Like freeze/thaw, blktrace
* functionality is not frequently used. There is no point in adding
* one more mutex to the block_device structure just for blktrace.
@@ -679,7 +679,7 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
if (!q)
return -ENXIO;

- mutex_lock(&bdev->bd_fsfreeze_mutex);
+ mutex_lock(&bdev->bd_fsfreeze_blktrace_mutex);

switch (cmd) {
case BLKTRACESETUP:
@@ -705,7 +705,7 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
break;
}

- mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ mutex_unlock(&bdev->bd_fsfreeze_blktrace_mutex);
return ret;
}

@@ -1741,7 +1741,7 @@ static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
if (q == NULL)
goto out_bdput;

- mutex_lock(&bdev->bd_fsfreeze_mutex);
+ mutex_lock(&bdev->bd_fsfreeze_blktrace_mutex);

if (attr == &dev_attr_enable) {
ret = sprintf(buf, "%u\n", !!q->blk_trace);
@@ -1760,7 +1760,7 @@ static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
ret = sprintf(buf, "%llu\n", q->blk_trace->end_lba);

out_unlock_bdev:
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ mutex_unlock(&bdev->bd_fsfreeze_blktrace_mutex);
out_bdput:
bdput(bdev);
out:
@@ -1802,7 +1802,7 @@ static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
if (q == NULL)
goto out_bdput;

- mutex_lock(&bdev->bd_fsfreeze_mutex);
+ mutex_lock(&bdev->bd_fsfreeze_blktrace_mutex);

if (attr == &dev_attr_enable) {
if (value)
@@ -1828,7 +1828,7 @@ static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
}

out_unlock_bdev:
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ mutex_unlock(&bdev->bd_fsfreeze_blktrace_mutex);
out_bdput:
bdput(bdev);
out:
--
1.8.3.1