| Message ID | 10602be89b1e8b940353fa64dfda47b6c27b14fa.1529516228.git.dsterba@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 06/21/2018 01:51 AM, David Sterba wrote: > Prepartory work to fix race between mount and device scan. > > The callers will have to manage the critical section, eg. mount wants > to scan and then call btrfs_open_devices without the ioctl scan walking > in and modifying the fs devices in the meantime. > > Signed-off-by: David Sterba <dsterba@suse.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Thanks, Anand > --- > fs/btrfs/super.c | 2 ++ > fs/btrfs/volumes.c | 4 ++-- > 2 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c > index 735402ed3154..ee82d02f5453 100644 > --- a/fs/btrfs/super.c > +++ b/fs/btrfs/super.c > @@ -1569,7 +1569,9 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type, > goto error_fs_info; > } > > + mutex_lock(&uuid_mutex); > error = btrfs_open_devices(fs_devices, mode, fs_type); > + mutex_unlock(&uuid_mutex); > if (error) > goto error_fs_info; > > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index 958bfe1a725c..5336d9832ba4 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -1145,7 +1145,8 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, > { > int ret; > > - mutex_lock(&uuid_mutex); > + lockdep_assert_held(&uuid_mutex); > + > mutex_lock(&fs_devices->device_list_mutex); > if (fs_devices->opened) { > fs_devices->opened++; > @@ -1155,7 +1156,6 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, > ret = open_fs_devices(fs_devices, flags, holder); > } > mutex_unlock(&fs_devices->device_list_mutex); > - mutex_unlock(&uuid_mutex); > > return ret; > } > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 735402ed3154..ee82d02f5453 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1569,7 +1569,9 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type, goto error_fs_info; } + mutex_lock(&uuid_mutex); error = btrfs_open_devices(fs_devices, mode, fs_type); + mutex_unlock(&uuid_mutex); if (error) goto error_fs_info; diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 958bfe1a725c..5336d9832ba4 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1145,7 +1145,8 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, { int ret; - mutex_lock(&uuid_mutex); + lockdep_assert_held(&uuid_mutex); + mutex_lock(&fs_devices->device_list_mutex); if (fs_devices->opened) { fs_devices->opened++; @@ -1155,7 +1156,6 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, ret = open_fs_devices(fs_devices, flags, holder); } mutex_unlock(&fs_devices->device_list_mutex); - mutex_unlock(&uuid_mutex); return ret; }
Prepartory work to fix race between mount and device scan. The callers will have to manage the critical section, eg. mount wants to scan and then call btrfs_open_devices without the ioctl scan walking in and modifying the fs devices in the meantime. Signed-off-by: David Sterba <dsterba@suse.com> --- fs/btrfs/super.c | 2 ++ fs/btrfs/volumes.c | 4 ++-- 2 files changed, 4 insertions(+), 2 deletions(-)