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author | Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> | 2011-04-20 10:09:16 (GMT) |
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committer | Chris Mason <chris.mason@oracle.com> | 2011-05-23 17:24:43 (GMT) |
commit | 1f78160ce1b1b8e657e2248118c4d91f881763f0 (patch) | |
tree | 98c5496a9ab3e77e4cd682c0487f4c0127198396 /fs/btrfs/ioctl.c | |
parent | 46224705656633466ca7dc71d81b3c0abc76cae4 (diff) | |
download | linux-fsl-qoriq-1f78160ce1b1b8e657e2248118c4d91f881763f0.tar.xz |
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.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index ce773fb..0de71fe 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; |