btrfs: zoned: wait until zone is finished when allocation didn't progress

When the allocated position doesn't progress, we cannot submit IOs to
finish a block group, but there should be ongoing IOs that will finish a
block group. So, in that case, we wait for a zone to be finished and retry
the allocation after that.

Introduce a new flag BTRFS_FS_NEED_ZONE_FINISH for fs_info->flags to
indicate we need a zone finish to have proceeded. The flag is set when the
allocator detected it cannot activate a new block group. And, it is cleared
once a zone is finished.

CC: stable@vger.kernel.org # 5.16+
Fixes: afba2bc036b0 ("btrfs: zoned: implement active zone tracking")
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 7859635d876ec2ff0e758a76c4e1b2145354f01c..202496172059c7e3480f8e9586119f250d0c82c3 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -638,6 +638,9 @@ enum {
        /* Indicate we have half completed snapshot deletions pending. */
        BTRFS_FS_UNFINISHED_DROPS,
 
+       /* Indicate we have to finish a zone to do next allocation. */
+       BTRFS_FS_NEED_ZONE_FINISH,
+
 #if BITS_PER_LONG == 32
        /* Indicate if we have error/warn message printed on 32bit systems */
        BTRFS_FS_32BIT_ERROR,
@@ -1086,6 +1089,8 @@ struct btrfs_fs_info {
 
        spinlock_t zone_active_bgs_lock;
        struct list_head zone_active_bgs;
+       /* Waiters when BTRFS_FS_NEED_ZONE_FINISH is set */
+       wait_queue_head_t zone_finish_wait;
 
        /* Updates are not protected by any lock */
        struct btrfs_commit_stats commit_stats;

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 90e513e54b48d579994e1a3c5de7eb75ed94bdd7..3fac429cf8a4075045fbbb4086ef9a690cb09dda 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3152,6 +3152,7 @@ void btrfs_init_fs_info(struct btrfs_fs_info *fs_info)
        init_waitqueue_head(&fs_info->transaction_blocked_wait);
        init_waitqueue_head(&fs_info->async_submit_wait);
        init_waitqueue_head(&fs_info->delayed_iputs_wait);
+       init_waitqueue_head(&fs_info->zone_finish_wait);
 
        /* Usable values until the real ones are cached from the superblock */
        fs_info->nodesize = 4096;

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index a8f9728355442173a6d94969a9553082e4e43fc5..16789bbacf75a71f7a68764e3692cb0d48be1b42 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1643,8 +1643,13 @@ static noinline int run_delalloc_zoned(struct btrfs_inode *inode,
                if (ret == 0)
                        done_offset = end;
 
-               if (done_offset == start)
-                       return -ENOSPC;
+               if (done_offset == start) {
+                       struct btrfs_fs_info *info = inode->root->fs_info;
+
+                       wait_var_event(&info->zone_finish_wait,
+                                      !test_bit(BTRFS_FS_NEED_ZONE_FINISH, &info->flags));
+                       continue;
+               }
 
                if (!locked_page_done) {
                        __set_page_dirty_nobuffers(locked_page);

diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 6c391b5b417284c523e903e822355836fe24cd06..b150b07ba1a7663c9b04c85307324d6819bd1b73 100644 (file)
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -2007,6 +2007,9 @@ static int do_zone_finish(struct btrfs_block_group *block_group, bool fully_writ
        /* For active_bg_list */
        btrfs_put_block_group(block_group);
 
+       clear_bit(BTRFS_FS_NEED_ZONE_FINISH, &fs_info->flags);
+       wake_up_all(&fs_info->zone_finish_wait);
+
        return 0;
 }
 
@@ -2043,6 +2046,9 @@ bool btrfs_can_activate_zone(struct btrfs_fs_devices *fs_devices, u64 flags)
        }
        mutex_unlock(&fs_info->chunk_mutex);
 
+       if (!ret)
+               set_bit(BTRFS_FS_NEED_ZONE_FINISH, &fs_info->flags);
+
        return ret;
 }