1 files changed, 35 insertions, 36 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index d3b58e388535..8b7eb22d508a 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4,6 +4,7 @@
  */
 
 #include <linux/sched.h>
+#include <linux/sched/mm.h>
 #include <linux/sched/signal.h>
 #include <linux/pagemap.h>
 #include <linux/writeback.h>
@@ -7888,33 +7889,6 @@ int btrfs_free_block_groups(struct btrfs_fs_info *info)
         return 0;
 }
 
-/* link_block_group will queue up kobjects to add when we're reclaim-safe */
-void btrfs_add_raid_kobjects(struct btrfs_fs_info *fs_info)
-{
-        struct btrfs_space_info *space_info;
-        struct raid_kobject *rkobj;
-        LIST_HEAD(list);
-        int ret = 0;
-
-        spin_lock(&fs_info->pending_raid_kobjs_lock);
-        list_splice_init(&fs_info->pending_raid_kobjs, &list);
-        spin_unlock(&fs_info->pending_raid_kobjs_lock);
-
-        list_for_each_entry(rkobj, &list, list) {
-                space_info = btrfs_find_space_info(fs_info, rkobj->flags);
-
-                ret = kobject_add(&rkobj->kobj, &space_info->kobj,
-                                "%s", btrfs_bg_type_to_raid_name(rkobj->flags));
-                if (ret) {
-                        kobject_put(&rkobj->kobj);
-                        break;
-                }
-        }
-        if (ret)
-                btrfs_warn(fs_info,
-                           "failed to add kobject for block cache, ignoring");
-}
-
 static void link_block_group(struct btrfs_block_group_cache *cache)
 {
         struct btrfs_space_info *space_info = cache->space_info;
@@ -7929,18 +7903,36 @@ static void link_block_group(struct btrfs_block_group_cache *cache)
         up_write(&space_info->groups_sem);
 
         if (first) {
-                struct raid_kobject *rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
+                struct raid_kobject *rkobj;
+                unsigned int nofs_flag;
+                int ret;
+
+                /*
+                 * Setup a NOFS context because kobject_add(), deep in its call
+                 * chain, does GFP_KERNEL allocations, and we are often called
+                 * in a context where if reclaim is triggered we can deadlock
+                 * (we are either holding a transaction handle or some lock
+                 * required for a transaction commit).
+                 */
+                nofs_flag = memalloc_nofs_save();
+                rkobj = kzalloc(sizeof(*rkobj), GFP_KERNEL);
                 if (!rkobj) {
+                        memalloc_nofs_restore(nofs_flag);
                         btrfs_warn(cache->fs_info,
                                 "couldn't alloc memory for raid level kobject");
                         return;
                 }
                 rkobj->flags = cache->flags;
                 kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
-
-                spin_lock(&fs_info->pending_raid_kobjs_lock);
-                list_add_tail(&rkobj->list, &fs_info->pending_raid_kobjs);
-                spin_unlock(&fs_info->pending_raid_kobjs_lock);
+                ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
+                                  btrfs_bg_type_to_raid_name(rkobj->flags));
+                memalloc_nofs_restore(nofs_flag);
+                if (ret) {
+                        kobject_put(&rkobj->kobj);
+                        btrfs_warn(fs_info,
+                           "failed to add kobject for block cache, ignoring");
+                        return;
+                }
                 space_info->block_group_kobjs[index] = &rkobj->kobj;
         }
 }
@@ -8206,7 +8198,6 @@ int btrfs_read_block_groups(struct btrfs_fs_info *info)
                         inc_block_group_ro(cache, 1);
         }
 
-        btrfs_add_raid_kobjects(info);
         btrfs_init_global_block_rsv(info);
         ret = check_chunk_block_group_mappings(info);
 error:
@@ -8975,6 +8966,7 @@ int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range)
         struct btrfs_device *device;
         struct list_head *devices;
         u64 group_trimmed;
+        u64 range_end = U64_MAX;
         u64 start;
         u64 end;
         u64 trimmed = 0;
@@ -8984,16 +8976,23 @@ int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range)
         int dev_ret = 0;
         int ret = 0;
 
+        /*
+         * Check range overflow if range->len is set.
+         * The default range->len is U64_MAX.
+         */
+        if (range->len != U64_MAX &&
+            check_add_overflow(range->start, range->len, &range_end))
+                return -EINVAL;
+
         cache = btrfs_lookup_first_block_group(fs_info, range->start);
         for (; cache; cache = next_block_group(cache)) {
-                if (cache->key.objectid >= (range->start + range->len)) {
+                if (cache->key.objectid >= range_end) {
                         btrfs_put_block_group(cache);
                         break;
                 }
 
                 start = max(range->start, cache->key.objectid);
-                end = min(range->start + range->len,
-                                cache->key.objectid + cache->key.offset);
+                end = min(range_end, cache->key.objectid + cache->key.offset);
 
                 if (end - start >= range->minlen) {
                         if (!block_group_cache_done(cache)) {