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authorXiao Guangrong <xiaoguangrong@cn.fujitsu.com>2011-04-20 10:09:16 +0000
committerChris Mason <chris.mason@oracle.com>2011-05-23 13:24:43 -0400
commit1f78160ce1b1b8e657e2248118c4d91f881763f0 (patch)
tree98c5496a9ab3e77e4cd682c0487f4c0127198396 /fs/btrfs/ioctl.c
parent46224705656633466ca7dc71d81b3c0abc76cae4 (diff)
Btrfs: using rcu lock in the reader side of devices list
fs_devices->devices is only updated on remove and add device paths, so we can use rcu to protect it in the reader side Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/ioctl.c')
-rw-r--r--fs/btrfs/ioctl.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index ce773fb736a1..0de71feb8e1c 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -281,8 +281,9 @@ static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- mutex_lock(&fs_info->fs_devices->device_list_mutex);
- list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) {
+ rcu_read_lock();
+ list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
+ dev_list) {
if (!device->bdev)
continue;
q = bdev_get_queue(device->bdev);
@@ -292,7 +293,7 @@ static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
minlen);
}
}
- mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ rcu_read_unlock();
if (!num_devices)
return -EOPNOTSUPP;