On 4.07.19 г. 18:24 ч., fdman...@kernel.org wrote:
> From: Filipe Manana <fdman...@suse.com>
>
> If we fail to start the inode caching thread, we print an error message
> and disable the inode cache, however we never wake up any waiters, so they
> hang forever waiting for the caching to finish. Fix this by waking them
> up and have them fallback to a call to btrfs_find_free_objectid().
>
> Fixes: e60efa84252c05 ("Btrfs: avoid triggering bug_on() when we fail to
> start inode caching task")
> Signed-off-by: Filipe Manana <fdman...@suse.com>
Reviewed-by: Nikolay Borisov <nbori...@suse.com>
> ---
> fs/btrfs/inode-map.c | 23 ++++++++++++++++++-----
> 1 file changed, 18 insertions(+), 5 deletions(-)
>
> diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
> index b210e8929c28..05b8c9927f29 100644
> --- a/fs/btrfs/inode-map.c
> +++ b/fs/btrfs/inode-map.c
> @@ -12,6 +12,19 @@
> #include "inode-map.h"
> #include "transaction.h"
>
> +static void fail_caching_thread(struct btrfs_root *root)
> +{
> + struct btrfs_fs_info *fs_info = root->fs_info;
> +
> + btrfs_warn(fs_info, "failed to start inode caching task");
> + btrfs_clear_pending_and_info(fs_info, INODE_MAP_CACHE,
> + "disabling inode map caching");
> + spin_lock(&root->ino_cache_lock);
> + root->ino_cache_state = BTRFS_CACHE_ERROR;
> + spin_unlock(&root->ino_cache_lock);
> + wake_up(&root->ino_cache_wait);
> +}
> +
> static int caching_kthread(void *data)
> {
> struct btrfs_root *root = data;
> @@ -164,11 +177,8 @@ static void start_caching(struct btrfs_root *root)
>
> tsk = kthread_run(caching_kthread, root, "btrfs-ino-cache-%llu",
> root->root_key.objectid);
> - if (IS_ERR(tsk)) {
> - btrfs_warn(fs_info, "failed to start inode caching task");
> - btrfs_clear_pending_and_info(fs_info, INODE_MAP_CACHE,
> - "disabling inode map caching");
> - }
> + if (IS_ERR(tsk))
> + fail_caching_thread(root);
> }
>
> int btrfs_find_free_ino(struct btrfs_root *root, u64 *objectid)
> @@ -186,11 +196,14 @@ int btrfs_find_free_ino(struct btrfs_root *root, u64
> *objectid)
>
> wait_event(root->ino_cache_wait,
> root->ino_cache_state == BTRFS_CACHE_FINISHED ||
> + root->ino_cache_state == BTRFS_CACHE_ERROR ||
> root->free_ino_ctl->free_space > 0);
>
> if (root->ino_cache_state == BTRFS_CACHE_FINISHED &&
> root->free_ino_ctl->free_space == 0)
> return -ENOSPC;
> + else if (root->ino_cache_state == BTRFS_CACHE_ERROR)
> + return btrfs_find_free_objectid(root, objectid);
> else
> goto again;
> }
>
