From a7d24c89db0b0b664046aebd1e0f9aef7306b944 Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Thu, 6 Sep 2018 17:18:14 -0400 Subject: [PATCH] btrfs: iterate all devices during trim, instead of fs_devices::alloc_list commit d4e329de5e5e21594df2e0dd59da9acee71f133b upstream. btrfs_trim_fs iterates over the fs_devices->alloc_list while holding the device_list_mutex. The problem is that ->alloc_list is protected by the chunk mutex. We don't want to hold the chunk mutex over the trim of the entire file system. Fortunately, the ->dev_list list is protected by the dev_list mutex and while it will give us all devices, including read-only devices, we already just skip the read-only devices. Then we can continue to take and release the chunk mutex while scanning each device. Fixes: 499f377f49f ("btrfs: iterate over unused chunk space in FITRIM") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Jeff Mahoney Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/extent-tree.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index a32c849..3ebef3a 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -11107,8 +11107,8 @@ int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range) "failed to trim %llu block group(s), last error %d", bg_failed, bg_ret); mutex_lock(&fs_info->fs_devices->device_list_mutex); - devices = &fs_info->fs_devices->alloc_list; - list_for_each_entry(device, devices, dev_alloc_list) { + devices = &fs_info->fs_devices->devices; + list_for_each_entry(device, devices, dev_list) { ret = btrfs_trim_free_extents(device, range->minlen, &group_trimmed); if (ret) { -- 2.7.4