From a68ebe0790fc88b4314d17984a2cf99ce2361901 Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Thu, 4 Jul 2019 16:24:32 +0100 Subject: [PATCH] Btrfs: fix inode cache waiters hanging on failure to start caching thread 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") Reviewed-by: Nikolay Borisov Signed-off-by: Filipe Manana Signed-off-by: David Sterba --- 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 45db4fb..c242ae4 100644 --- a/fs/btrfs/inode-map.c +++ b/fs/btrfs/inode-map.c @@ -13,6 +13,19 @@ #include "transaction.h" #include "delalloc-space.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; @@ -165,11 +178,8 @@ 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) @@ -187,11 +197,14 @@ again: 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; } -- 2.7.4