Linux-BTRFS Archive on lore.kernel.org
 help / color / Atom feed
From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Filipe Manana <fdmanana@suse.com>,
	Nikolay Borisov <nborisov@suse.com>,
	David Sterba <dsterba@suse.com>, Sasha Levin <sashal@kernel.org>,
	linux-btrfs@vger.kernel.org
Subject: [PATCH AUTOSEL 4.14 292/371] Btrfs: fix inode cache waiters hanging on failure to start caching thread
Date: Thu, 16 Jan 2020 12:22:44 -0500
Message-ID: <20200116172403.18149-235-sashal@kernel.org> (raw)
In-Reply-To: <20200116172403.18149-1-sashal@kernel.org>

From: Filipe Manana <fdmanana@suse.com>

[ Upstream commit a68ebe0790fc88b4314d17984a2cf99ce2361901 ]

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 <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 7dc2923655d9..b1c3a4ec76c8 100644
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -26,6 +26,19 @@
 #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;
@@ -178,11 +191,8 @@ 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)
@@ -200,11 +210,14 @@ 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;
 }
-- 
2.20.1


  parent reply index

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20200116172403.18149-1-sashal@kernel.org>
2020-01-16 17:22 ` [PATCH AUTOSEL 4.14 291/371] Btrfs: fix hang when loading existing inode cache off disk Sasha Levin
2020-01-16 17:22 ` Sasha Levin [this message]
2020-01-16 17:22 ` [PATCH AUTOSEL 4.14 293/371] Btrfs: fix inode cache waiters hanging on path allocation failure Sasha Levin
2020-01-16 17:22 ` [PATCH AUTOSEL 4.14 294/371] btrfs: use correct count in btrfs_file_write_iter() Sasha Levin

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200116172403.18149-235-sashal@kernel.org \
    --to=sashal@kernel.org \
    --cc=dsterba@suse.com \
    --cc=fdmanana@suse.com \
    --cc=linux-btrfs@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=nborisov@suse.com \
    --cc=stable@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-BTRFS Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-btrfs/0 linux-btrfs/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-btrfs linux-btrfs/ https://lore.kernel.org/linux-btrfs \
		linux-btrfs@vger.kernel.org
	public-inbox-index linux-btrfs

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-btrfs


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git