The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From fcc99734d1d4ced30167eb02e17f656735cb9928 Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu(a)suse.com>
Date: Mon, 27 Apr 2020 14:50:14 +0800
Subject: [PATCH] btrfs: transaction: Avoid deadlock due to bad initialization
timing of fs_info::journal_info
[BUG]
One run of btrfs/063 triggered the following lockdep warning:
============================================
WARNING: possible recursive locking detected
5.6.0-rc7-custom+ #48 Not tainted
--------------------------------------------
kworker/u24:0/7 is trying to acquire lock:
ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
but task is already holding lock:
ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(sb_internal#2);
lock(sb_internal#2);
*** DEADLOCK ***
May be due to missing lock nesting notation
4 locks held by kworker/u24:0/7:
#0: ffff88817b495948 ((wq_completion)btrfs-endio-write){+.+.}, at: process_one_work+0x557/0xb80
#1: ffff888189ea7db8 ((work_completion)(&work->normal_work)){+.+.}, at: process_one_work+0x557/0xb80
#2: ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
#3: ffff888174ca4da8 (&fs_info->reloc_mutex){+.+.}, at: btrfs_record_root_in_trans+0x83/0xd0 [btrfs]
stack backtrace:
CPU: 0 PID: 7 Comm: kworker/u24:0 Not tainted 5.6.0-rc7-custom+ #48
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
Call Trace:
dump_stack+0xc2/0x11a
__lock_acquire.cold+0xce/0x214
lock_acquire+0xe6/0x210
__sb_start_write+0x14e/0x290
start_transaction+0x66c/0x890 [btrfs]
btrfs_join_transaction+0x1d/0x20 [btrfs]
find_free_extent+0x1504/0x1a50 [btrfs]
btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
btrfs_alloc_tree_block+0x1ac/0x570 [btrfs]
btrfs_copy_root+0x213/0x580 [btrfs]
create_reloc_root+0x3bd/0x470 [btrfs]
btrfs_init_reloc_root+0x2d2/0x310 [btrfs]
record_root_in_trans+0x191/0x1d0 [btrfs]
btrfs_record_root_in_trans+0x90/0xd0 [btrfs]
start_transaction+0x16e/0x890 [btrfs]
btrfs_join_transaction+0x1d/0x20 [btrfs]
btrfs_finish_ordered_io+0x55d/0xcd0 [btrfs]
finish_ordered_fn+0x15/0x20 [btrfs]
btrfs_work_helper+0x116/0x9a0 [btrfs]
process_one_work+0x632/0xb80
worker_thread+0x80/0x690
kthread+0x1a3/0x1f0
ret_from_fork+0x27/0x50
It's pretty hard to reproduce, only one hit so far.
[CAUSE]
This is because we're calling btrfs_join_transaction() without re-using
the current running one:
btrfs_finish_ordered_io()
|- btrfs_join_transaction() <<< Call #1
|- btrfs_record_root_in_trans()
|- btrfs_reserve_extent()
|- btrfs_join_transaction() <<< Call #2
Normally such btrfs_join_transaction() call should re-use the existing
one, without trying to re-start a transaction.
But the problem is, in btrfs_join_transaction() call #1, we call
btrfs_record_root_in_trans() before initializing current::journal_info.
And in btrfs_join_transaction() call #2, we're relying on
current::journal_info to avoid such deadlock.
[FIX]
Call btrfs_record_root_in_trans() after we have initialized
current::journal_info.
CC: stable(a)vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu(a)suse.com>
Reviewed-by: David Sterba <dsterba(a)suse.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 8cede6eb9843..2d5498136e5e 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -662,10 +662,19 @@ start_transaction(struct btrfs_root *root, unsigned int num_items,
}
got_it:
- btrfs_record_root_in_trans(h, root);
-
if (!current->journal_info)
current->journal_info = h;
+
+ /*
+ * btrfs_record_root_in_trans() needs to alloc new extents, and may
+ * call btrfs_join_transaction() while we're also starting a
+ * transaction.
+ *
+ * Thus it need to be called after current->journal_info initialized,
+ * or we can deadlock.
+ */
+ btrfs_record_root_in_trans(h, root);
+
return h;
join_fail:
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From fcc99734d1d4ced30167eb02e17f656735cb9928 Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu(a)suse.com>
Date: Mon, 27 Apr 2020 14:50:14 +0800
Subject: [PATCH] btrfs: transaction: Avoid deadlock due to bad initialization
timing of fs_info::journal_info
[BUG]
One run of btrfs/063 triggered the following lockdep warning:
============================================
WARNING: possible recursive locking detected
5.6.0-rc7-custom+ #48 Not tainted
--------------------------------------------
kworker/u24:0/7 is trying to acquire lock:
ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
but task is already holding lock:
ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(sb_internal#2);
lock(sb_internal#2);
*** DEADLOCK ***
May be due to missing lock nesting notation
4 locks held by kworker/u24:0/7:
#0: ffff88817b495948 ((wq_completion)btrfs-endio-write){+.+.}, at: process_one_work+0x557/0xb80
#1: ffff888189ea7db8 ((work_completion)(&work->normal_work)){+.+.}, at: process_one_work+0x557/0xb80
#2: ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
#3: ffff888174ca4da8 (&fs_info->reloc_mutex){+.+.}, at: btrfs_record_root_in_trans+0x83/0xd0 [btrfs]
stack backtrace:
CPU: 0 PID: 7 Comm: kworker/u24:0 Not tainted 5.6.0-rc7-custom+ #48
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
Call Trace:
dump_stack+0xc2/0x11a
__lock_acquire.cold+0xce/0x214
lock_acquire+0xe6/0x210
__sb_start_write+0x14e/0x290
start_transaction+0x66c/0x890 [btrfs]
btrfs_join_transaction+0x1d/0x20 [btrfs]
find_free_extent+0x1504/0x1a50 [btrfs]
btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
btrfs_alloc_tree_block+0x1ac/0x570 [btrfs]
btrfs_copy_root+0x213/0x580 [btrfs]
create_reloc_root+0x3bd/0x470 [btrfs]
btrfs_init_reloc_root+0x2d2/0x310 [btrfs]
record_root_in_trans+0x191/0x1d0 [btrfs]
btrfs_record_root_in_trans+0x90/0xd0 [btrfs]
start_transaction+0x16e/0x890 [btrfs]
btrfs_join_transaction+0x1d/0x20 [btrfs]
btrfs_finish_ordered_io+0x55d/0xcd0 [btrfs]
finish_ordered_fn+0x15/0x20 [btrfs]
btrfs_work_helper+0x116/0x9a0 [btrfs]
process_one_work+0x632/0xb80
worker_thread+0x80/0x690
kthread+0x1a3/0x1f0
ret_from_fork+0x27/0x50
It's pretty hard to reproduce, only one hit so far.
[CAUSE]
This is because we're calling btrfs_join_transaction() without re-using
the current running one:
btrfs_finish_ordered_io()
|- btrfs_join_transaction() <<< Call #1
|- btrfs_record_root_in_trans()
|- btrfs_reserve_extent()
|- btrfs_join_transaction() <<< Call #2
Normally such btrfs_join_transaction() call should re-use the existing
one, without trying to re-start a transaction.
But the problem is, in btrfs_join_transaction() call #1, we call
btrfs_record_root_in_trans() before initializing current::journal_info.
And in btrfs_join_transaction() call #2, we're relying on
current::journal_info to avoid such deadlock.
[FIX]
Call btrfs_record_root_in_trans() after we have initialized
current::journal_info.
CC: stable(a)vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu(a)suse.com>
Reviewed-by: David Sterba <dsterba(a)suse.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 8cede6eb9843..2d5498136e5e 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -662,10 +662,19 @@ start_transaction(struct btrfs_root *root, unsigned int num_items,
}
got_it:
- btrfs_record_root_in_trans(h, root);
-
if (!current->journal_info)
current->journal_info = h;
+
+ /*
+ * btrfs_record_root_in_trans() needs to alloc new extents, and may
+ * call btrfs_join_transaction() while we're also starting a
+ * transaction.
+ *
+ * Thus it need to be called after current->journal_info initialized,
+ * or we can deadlock.
+ */
+ btrfs_record_root_in_trans(h, root);
+
return h;
join_fail:
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From fcc99734d1d4ced30167eb02e17f656735cb9928 Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu(a)suse.com>
Date: Mon, 27 Apr 2020 14:50:14 +0800
Subject: [PATCH] btrfs: transaction: Avoid deadlock due to bad initialization
timing of fs_info::journal_info
[BUG]
One run of btrfs/063 triggered the following lockdep warning:
============================================
WARNING: possible recursive locking detected
5.6.0-rc7-custom+ #48 Not tainted
--------------------------------------------
kworker/u24:0/7 is trying to acquire lock:
ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
but task is already holding lock:
ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(sb_internal#2);
lock(sb_internal#2);
*** DEADLOCK ***
May be due to missing lock nesting notation
4 locks held by kworker/u24:0/7:
#0: ffff88817b495948 ((wq_completion)btrfs-endio-write){+.+.}, at: process_one_work+0x557/0xb80
#1: ffff888189ea7db8 ((work_completion)(&work->normal_work)){+.+.}, at: process_one_work+0x557/0xb80
#2: ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
#3: ffff888174ca4da8 (&fs_info->reloc_mutex){+.+.}, at: btrfs_record_root_in_trans+0x83/0xd0 [btrfs]
stack backtrace:
CPU: 0 PID: 7 Comm: kworker/u24:0 Not tainted 5.6.0-rc7-custom+ #48
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
Call Trace:
dump_stack+0xc2/0x11a
__lock_acquire.cold+0xce/0x214
lock_acquire+0xe6/0x210
__sb_start_write+0x14e/0x290
start_transaction+0x66c/0x890 [btrfs]
btrfs_join_transaction+0x1d/0x20 [btrfs]
find_free_extent+0x1504/0x1a50 [btrfs]
btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
btrfs_alloc_tree_block+0x1ac/0x570 [btrfs]
btrfs_copy_root+0x213/0x580 [btrfs]
create_reloc_root+0x3bd/0x470 [btrfs]
btrfs_init_reloc_root+0x2d2/0x310 [btrfs]
record_root_in_trans+0x191/0x1d0 [btrfs]
btrfs_record_root_in_trans+0x90/0xd0 [btrfs]
start_transaction+0x16e/0x890 [btrfs]
btrfs_join_transaction+0x1d/0x20 [btrfs]
btrfs_finish_ordered_io+0x55d/0xcd0 [btrfs]
finish_ordered_fn+0x15/0x20 [btrfs]
btrfs_work_helper+0x116/0x9a0 [btrfs]
process_one_work+0x632/0xb80
worker_thread+0x80/0x690
kthread+0x1a3/0x1f0
ret_from_fork+0x27/0x50
It's pretty hard to reproduce, only one hit so far.
[CAUSE]
This is because we're calling btrfs_join_transaction() without re-using
the current running one:
btrfs_finish_ordered_io()
|- btrfs_join_transaction() <<< Call #1
|- btrfs_record_root_in_trans()
|- btrfs_reserve_extent()
|- btrfs_join_transaction() <<< Call #2
Normally such btrfs_join_transaction() call should re-use the existing
one, without trying to re-start a transaction.
But the problem is, in btrfs_join_transaction() call #1, we call
btrfs_record_root_in_trans() before initializing current::journal_info.
And in btrfs_join_transaction() call #2, we're relying on
current::journal_info to avoid such deadlock.
[FIX]
Call btrfs_record_root_in_trans() after we have initialized
current::journal_info.
CC: stable(a)vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu(a)suse.com>
Reviewed-by: David Sterba <dsterba(a)suse.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 8cede6eb9843..2d5498136e5e 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -662,10 +662,19 @@ start_transaction(struct btrfs_root *root, unsigned int num_items,
}
got_it:
- btrfs_record_root_in_trans(h, root);
-
if (!current->journal_info)
current->journal_info = h;
+
+ /*
+ * btrfs_record_root_in_trans() needs to alloc new extents, and may
+ * call btrfs_join_transaction() while we're also starting a
+ * transaction.
+ *
+ * Thus it need to be called after current->journal_info initialized,
+ * or we can deadlock.
+ */
+ btrfs_record_root_in_trans(h, root);
+
return h;
join_fail:
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From f6033c5e333238f299c3ae03fac8cc1365b23b77 Mon Sep 17 00:00:00 2001
From: Xiyu Yang <xiyuyang19(a)fudan.edu.cn>
Date: Tue, 21 Apr 2020 10:54:11 +0800
Subject: [PATCH] btrfs: fix block group leak when removing fails
btrfs_remove_block_group() invokes btrfs_lookup_block_group(), which
returns a local reference of the block group that contains the given
bytenr to "block_group" with increased refcount.
When btrfs_remove_block_group() returns, "block_group" becomes invalid,
so the refcount should be decreased to keep refcount balanced.
The reference counting issue happens in several exception handling paths
of btrfs_remove_block_group(). When those error scenarios occur such as
btrfs_alloc_path() returns NULL, the function forgets to decrease its
refcnt increased by btrfs_lookup_block_group() and will cause a refcnt
leak.
Fix this issue by jumping to "out_put_group" label and calling
btrfs_put_block_group() when those error scenarios occur.
CC: stable(a)vger.kernel.org # 4.4+
Signed-off-by: Xiyu Yang <xiyuyang19(a)fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf(a)gmail.com>
Reviewed-by: David Sterba <dsterba(a)suse.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index af9e9a008724..696f47103cfc 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -916,7 +916,7 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
- goto out;
+ goto out_put_group;
}
/*
@@ -954,7 +954,7 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
ret = btrfs_orphan_add(trans, BTRFS_I(inode));
if (ret) {
btrfs_add_delayed_iput(inode);
- goto out;
+ goto out_put_group;
}
clear_nlink(inode);
/* One for the block groups ref */
@@ -977,13 +977,13 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
if (ret < 0)
- goto out;
+ goto out_put_group;
if (ret > 0)
btrfs_release_path(path);
if (ret == 0) {
ret = btrfs_del_item(trans, tree_root, path);
if (ret)
- goto out;
+ goto out_put_group;
btrfs_release_path(path);
}
@@ -1102,9 +1102,9 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
ret = remove_block_group_free_space(trans, block_group);
if (ret)
- goto out;
+ goto out_put_group;
- btrfs_put_block_group(block_group);
+ /* Once for the block groups rbtree */
btrfs_put_block_group(block_group);
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
@@ -1127,6 +1127,10 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
/* once for the tree */
free_extent_map(em);
}
+
+out_put_group:
+ /* Once for the lookup reference */
+ btrfs_put_block_group(block_group);
out:
if (remove_rsv)
btrfs_delayed_refs_rsv_release(fs_info, 1);
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 1402d17dfd9657be0da8458b2079d03c2d61c86a Mon Sep 17 00:00:00 2001
From: Xiyu Yang <xiyuyang19(a)fudan.edu.cn>
Date: Mon, 20 Apr 2020 13:39:39 +0800
Subject: [PATCH] btrfs: fix transaction leak in btrfs_recover_relocation
btrfs_recover_relocation() invokes btrfs_join_transaction(), which joins
a btrfs_trans_handle object into transactions and returns a reference of
it with increased refcount to "trans".
When btrfs_recover_relocation() returns, "trans" becomes invalid, so the
refcount should be decreased to keep refcount balanced.
The reference counting issue happens in one exception handling path of
btrfs_recover_relocation(). When read_fs_root() failed, the refcnt
increased by btrfs_join_transaction() is not decreased, causing a refcnt
leak.
Fix this issue by calling btrfs_end_transaction() on this error path
when read_fs_root() failed.
Fixes: 79787eaab461 ("btrfs: replace many BUG_ONs with proper error handling")
CC: stable(a)vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana(a)suse.com>
Signed-off-by: Xiyu Yang <xiyuyang19(a)fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf(a)gmail.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index d35936c934ab..03bc7134e8cb 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -4559,6 +4559,7 @@ int btrfs_recover_relocation(struct btrfs_root *root)
if (IS_ERR(fs_root)) {
err = PTR_ERR(fs_root);
list_add_tail(&reloc_root->root_list, &reloc_roots);
+ btrfs_end_transaction(trans);
goto out_unset;
}
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 1402d17dfd9657be0da8458b2079d03c2d61c86a Mon Sep 17 00:00:00 2001
From: Xiyu Yang <xiyuyang19(a)fudan.edu.cn>
Date: Mon, 20 Apr 2020 13:39:39 +0800
Subject: [PATCH] btrfs: fix transaction leak in btrfs_recover_relocation
btrfs_recover_relocation() invokes btrfs_join_transaction(), which joins
a btrfs_trans_handle object into transactions and returns a reference of
it with increased refcount to "trans".
When btrfs_recover_relocation() returns, "trans" becomes invalid, so the
refcount should be decreased to keep refcount balanced.
The reference counting issue happens in one exception handling path of
btrfs_recover_relocation(). When read_fs_root() failed, the refcnt
increased by btrfs_join_transaction() is not decreased, causing a refcnt
leak.
Fix this issue by calling btrfs_end_transaction() on this error path
when read_fs_root() failed.
Fixes: 79787eaab461 ("btrfs: replace many BUG_ONs with proper error handling")
CC: stable(a)vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana(a)suse.com>
Signed-off-by: Xiyu Yang <xiyuyang19(a)fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf(a)gmail.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index d35936c934ab..03bc7134e8cb 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -4559,6 +4559,7 @@ int btrfs_recover_relocation(struct btrfs_root *root)
if (IS_ERR(fs_root)) {
err = PTR_ERR(fs_root);
list_add_tail(&reloc_root->root_list, &reloc_roots);
+ btrfs_end_transaction(trans);
goto out_unset;
}
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 1402d17dfd9657be0da8458b2079d03c2d61c86a Mon Sep 17 00:00:00 2001
From: Xiyu Yang <xiyuyang19(a)fudan.edu.cn>
Date: Mon, 20 Apr 2020 13:39:39 +0800
Subject: [PATCH] btrfs: fix transaction leak in btrfs_recover_relocation
btrfs_recover_relocation() invokes btrfs_join_transaction(), which joins
a btrfs_trans_handle object into transactions and returns a reference of
it with increased refcount to "trans".
When btrfs_recover_relocation() returns, "trans" becomes invalid, so the
refcount should be decreased to keep refcount balanced.
The reference counting issue happens in one exception handling path of
btrfs_recover_relocation(). When read_fs_root() failed, the refcnt
increased by btrfs_join_transaction() is not decreased, causing a refcnt
leak.
Fix this issue by calling btrfs_end_transaction() on this error path
when read_fs_root() failed.
Fixes: 79787eaab461 ("btrfs: replace many BUG_ONs with proper error handling")
CC: stable(a)vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana(a)suse.com>
Signed-off-by: Xiyu Yang <xiyuyang19(a)fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf(a)gmail.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index d35936c934ab..03bc7134e8cb 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -4559,6 +4559,7 @@ int btrfs_recover_relocation(struct btrfs_root *root)
if (IS_ERR(fs_root)) {
err = PTR_ERR(fs_root);
list_add_tail(&reloc_root->root_list, &reloc_roots);
+ btrfs_end_transaction(trans);
goto out_unset;
}
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 85e9b88af1e6164f19ec71381efd5e2bcfc17620 Mon Sep 17 00:00:00 2001
From: Vasily Averin <vvs(a)virtuozzo.com>
Date: Mon, 27 Apr 2020 08:32:46 +0300
Subject: [PATCH] drm/qxl: qxl_release leak in qxl_draw_dirty_fb()
ret should be changed to release allocated struct qxl_release
Cc: stable(a)vger.kernel.org
Fixes: 8002db6336dd ("qxl: convert qxl driver to proper use for reservations")
Signed-off-by: Vasily Averin <vvs(a)virtuozzo.com>
Link: http://patchwork.freedesktop.org/patch/msgid/22cfd55f-07c8-95d0-a2f7-191b71…
Signed-off-by: Gerd Hoffmann <kraxel(a)redhat.com>
diff --git a/drivers/gpu/drm/qxl/qxl_draw.c b/drivers/gpu/drm/qxl/qxl_draw.c
index 5bebf1ea1c5d..f8776d60d08e 100644
--- a/drivers/gpu/drm/qxl/qxl_draw.c
+++ b/drivers/gpu/drm/qxl/qxl_draw.c
@@ -209,9 +209,10 @@ void qxl_draw_dirty_fb(struct qxl_device *qdev,
goto out_release_backoff;
rects = drawable_set_clipping(qdev, num_clips, clips_bo);
- if (!rects)
+ if (!rects) {
+ ret = -EINVAL;
goto out_release_backoff;
-
+ }
drawable = (struct qxl_drawable *)qxl_release_map(qdev, release);
drawable->clip.type = SPICE_CLIP_TYPE_RECTS;