From: Jeff Mahoney Date: Thu, 6 Sep 2018 21:18:14 +0000 (-0400) Subject: btrfs: iterate all devices during trim, instead of fs_devices::alloc_list X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=d4e329de5e5e21594df2e0dd59da9acee71f133b;p=openwrt%2Fstaging%2Fblogic.git btrfs: iterate all devices during trim, instead of fs_devices::alloc_list 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 --- diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index da3257585e29..41fb24da7afa 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -10903,8 +10903,8 @@ 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) {