[arch-commits] Commit in linux/trunk (3 files)
Evangelos Foutras
foutrelis at archlinux.org
Tue Jun 30 08:11:00 UTC 2015
Date: Tuesday, June 30, 2015 @ 10:11:00
Author: foutrelis
Revision: 241420
upgpkg: linux 4.0.7-2
Fix deadlock with stacked loop devices (FS#45129).
Added:
linux/trunk/0001-block-loop-convert-to-per-device-workqueue.patch
linux/trunk/0002-block-loop-avoiding-too-many-pending-per-work-I-O.patch
Modified:
linux/trunk/PKGBUILD
--------------------------------------------------------------+
0001-block-loop-convert-to-per-device-workqueue.patch | 133 ++++++++++
0002-block-loop-avoiding-too-many-pending-per-work-I-O.patch | 52 +++
PKGBUILD | 11
3 files changed, 195 insertions(+), 1 deletion(-)
Added: 0001-block-loop-convert-to-per-device-workqueue.patch
===================================================================
--- 0001-block-loop-convert-to-per-device-workqueue.patch (rev 0)
+++ 0001-block-loop-convert-to-per-device-workqueue.patch 2015-06-30 08:11:00 UTC (rev 241420)
@@ -0,0 +1,133 @@
+From ebcacf05168d9791d39c5434164c64b9ef937171 Mon Sep 17 00:00:00 2001
+From: Ming Lei <ming.lei at canonical.com>
+Date: Tue, 5 May 2015 19:49:54 +0800
+Subject: [PATCH 1/2] block: loop: convert to per-device workqueue
+
+Documentation/workqueue.txt:
+ If there is dependency among multiple work items used
+ during memory reclaim, they should be queued to separate
+ wq each with WQ_MEM_RECLAIM.
+
+Loop devices can be stacked, so we have to convert to per-device
+workqueue. One example is Fedora live CD.
+
+Fixes: b5dd2f6047ca108001328aac0e8588edd15f1778
+Cc: stable at vger.kernel.org (v4.0)
+Cc: Justin M. Forbes <jforbes at fedoraproject.org>
+Signed-off-by: Ming Lei <ming.lei at canonical.com>
+Acked-by: Tejun Heo <tj at kernel.org>
+Signed-off-by: Jens Axboe <axboe at fb.com>
+---
+ drivers/block/loop.c | 30 ++++++++++++++----------------
+ drivers/block/loop.h | 1 +
+ 2 files changed, 15 insertions(+), 16 deletions(-)
+
+diff --git a/drivers/block/loop.c b/drivers/block/loop.c
+index d1f168b..fec06d5 100644
+--- a/drivers/block/loop.c
++++ b/drivers/block/loop.c
+@@ -85,8 +85,6 @@ static DEFINE_MUTEX(loop_index_mutex);
+ static int max_part;
+ static int part_shift;
+
+-static struct workqueue_struct *loop_wq;
+-
+ /*
+ * Transfer functions
+ */
+@@ -777,6 +775,12 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
+ size = get_loop_size(lo, file);
+ if ((loff_t)(sector_t)size != size)
+ goto out_putf;
++ error = -ENOMEM;
++ lo->wq = alloc_workqueue("kloopd%d",
++ WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_UNBOUND, 0,
++ lo->lo_number);
++ if (!lo->wq)
++ goto out_putf;
+
+ error = 0;
+
+@@ -924,6 +928,8 @@ static int loop_clr_fd(struct loop_device *lo)
+ lo->lo_flags = 0;
+ if (!part_shift)
+ lo->lo_disk->flags |= GENHD_FL_NO_PART_SCAN;
++ destroy_workqueue(lo->wq);
++ lo->wq = NULL;
+ mutex_unlock(&lo->lo_ctl_mutex);
+ /*
+ * Need not hold lo_ctl_mutex to fput backing file.
+@@ -1477,9 +1483,13 @@ static int loop_queue_rq(struct blk_mq_hw_ctx *hctx,
+ const struct blk_mq_queue_data *bd)
+ {
+ struct loop_cmd *cmd = blk_mq_rq_to_pdu(bd->rq);
++ struct loop_device *lo = cmd->rq->q->queuedata;
+
+ blk_mq_start_request(bd->rq);
+
++ if (lo->lo_state != Lo_bound)
++ return -EIO;
++
+ if (cmd->rq->cmd_flags & REQ_WRITE) {
+ struct loop_device *lo = cmd->rq->q->queuedata;
+ bool need_sched = true;
+@@ -1493,9 +1503,9 @@ static int loop_queue_rq(struct blk_mq_hw_ctx *hctx,
+ spin_unlock_irq(&lo->lo_lock);
+
+ if (need_sched)
+- queue_work(loop_wq, &lo->write_work);
++ queue_work(lo->wq, &lo->write_work);
+ } else {
+- queue_work(loop_wq, &cmd->read_work);
++ queue_work(lo->wq, &cmd->read_work);
+ }
+
+ return BLK_MQ_RQ_QUEUE_OK;
+@@ -1507,9 +1517,6 @@ static void loop_handle_cmd(struct loop_cmd *cmd)
+ struct loop_device *lo = cmd->rq->q->queuedata;
+ int ret = -EIO;
+
+- if (lo->lo_state != Lo_bound)
+- goto failed;
+-
+ if (write && (lo->lo_flags & LO_FLAGS_READ_ONLY))
+ goto failed;
+
+@@ -1858,13 +1865,6 @@ static int __init loop_init(void)
+ goto misc_out;
+ }
+
+- loop_wq = alloc_workqueue("kloopd",
+- WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_UNBOUND, 0);
+- if (!loop_wq) {
+- err = -ENOMEM;
+- goto misc_out;
+- }
+-
+ blk_register_region(MKDEV(LOOP_MAJOR, 0), range,
+ THIS_MODULE, loop_probe, NULL, NULL);
+
+@@ -1902,8 +1902,6 @@ static void __exit loop_exit(void)
+ blk_unregister_region(MKDEV(LOOP_MAJOR, 0), range);
+ unregister_blkdev(LOOP_MAJOR, "loop");
+
+- destroy_workqueue(loop_wq);
+-
+ misc_deregister(&loop_misc);
+ }
+
+diff --git a/drivers/block/loop.h b/drivers/block/loop.h
+index 301c27f..49564ed 100644
+--- a/drivers/block/loop.h
++++ b/drivers/block/loop.h
+@@ -54,6 +54,7 @@ struct loop_device {
+ gfp_t old_gfp_mask;
+
+ spinlock_t lo_lock;
++ struct workqueue_struct *wq;
+ struct list_head write_cmd_head;
+ struct work_struct write_work;
+ bool write_started;
+--
+2.4.5
+
Added: 0002-block-loop-avoiding-too-many-pending-per-work-I-O.patch
===================================================================
--- 0002-block-loop-avoiding-too-many-pending-per-work-I-O.patch (rev 0)
+++ 0002-block-loop-avoiding-too-many-pending-per-work-I-O.patch 2015-06-30 08:11:00 UTC (rev 241420)
@@ -0,0 +1,52 @@
+From 02a6b08b2706501fb0fe6ff2df2f7d8377f2f69b Mon Sep 17 00:00:00 2001
+From: Ming Lei <ming.lei at canonical.com>
+Date: Tue, 5 May 2015 19:49:55 +0800
+Subject: [PATCH 2/2] block: loop: avoiding too many pending per work I/O
+
+If there are too many pending per work I/O, too many
+high priority work thread can be generated so that
+system performance can be effected.
+
+This patch limits the max_active parameter of workqueue as 16.
+
+This patch fixes Fedora 22 live booting performance
+regression when it is booted from squashfs over dm
+based on loop, and looks the following reasons are
+related with the problem:
+
+- not like other filesyststems(such as ext4), squashfs
+is a bit special, and I observed that increasing I/O jobs
+to access file in squashfs only improve I/O performance a
+little, but it can make big difference for ext4
+
+- nested loop: both squashfs.img and ext3fs.img are mounted
+as loop block, and ext3fs.img is inside the squashfs
+
+- during booting, lots of tasks may run concurrently
+
+Fixes: b5dd2f6047ca108001328aac0e8588edd15f1778
+Cc: stable at vger.kernel.org (v4.0)
+Cc: Justin M. Forbes <jforbes at fedoraproject.org>
+Signed-off-by: Ming Lei <ming.lei at canonical.com>
+Acked-by: Tejun Heo <tj at kernel.org>
+Signed-off-by: Jens Axboe <axboe at fb.com>
+---
+ drivers/block/loop.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/drivers/block/loop.c b/drivers/block/loop.c
+index fec06d5..daaaf70 100644
+--- a/drivers/block/loop.c
++++ b/drivers/block/loop.c
+@@ -777,7 +777,7 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
+ goto out_putf;
+ error = -ENOMEM;
+ lo->wq = alloc_workqueue("kloopd%d",
+- WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_UNBOUND, 0,
++ WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_UNBOUND, 16,
+ lo->lo_number);
+ if (!lo->wq)
+ goto out_putf;
+--
+2.4.5
+
Modified: PKGBUILD
===================================================================
--- PKGBUILD 2015-06-30 07:50:03 UTC (rev 241419)
+++ PKGBUILD 2015-06-30 08:11:00 UTC (rev 241420)
@@ -6,7 +6,7 @@
#pkgbase=linux-custom # Build kernel with a different name
_srcname=linux-4.0
pkgver=4.0.7
-pkgrel=1
+pkgrel=2
arch=('i686' 'x86_64')
url="http://www.kernel.org/"
license=('GPL2')
@@ -20,6 +20,8 @@
'config' 'config.x86_64'
# standard config files for mkinitcpio ramdisk
'linux.preset'
+ '0001-block-loop-convert-to-per-device-workqueue.patch'
+ '0002-block-loop-avoiding-too-many-pending-per-work-I-O.patch'
'change-default-console-loglevel.patch')
sha256sums=('0f2f7d44979bc8f71c4fc5d3308c03499c26a824dd311fdf6eef4dee0d7d5991'
'SKIP'
@@ -28,6 +30,8 @@
'e8d639582697f22333a96aa1614bcf5d9bcf2e6683a3d5296f9cfc64843606f1'
'5dadd75693e512b77f87f5620e470405b943373613eaf4df561037e9296453be'
'f0d90e756f14533ee67afda280500511a62465b4f76adcc5effa95a40045179c'
+ '0682df710e8d23f0d420b3b01fbfe409b3911940b1a379b78d9f4a5ac8590386'
+ 'af42b1456caee0b0db8f3cc770c78083b40159260b99db4930e503ac7824eacc'
'1256b241cd477b265a3c2d64bdc19ffe3c9bbcee82ea3994c590c2c76e767d99')
validpgpkeys=(
'ABAF11C65A2970B130ABE3C479BE3E4300411886' # Linus Torvalds
@@ -45,6 +49,11 @@
# add latest fixes from stable queue, if needed
# http://git.kernel.org/?p=linux/kernel/git/stable/stable-queue.git
+ # Fix deadlock with stacked loop devices (FS#45129)
+ # http://marc.info/?l=linux-kernel&m=143280649731902&w=2
+ patch -Np1 -i ../0001-block-loop-convert-to-per-device-workqueue.patch
+ patch -Np1 -i ../0002-block-loop-avoiding-too-many-pending-per-work-I-O.patch
+
# set DEFAULT_CONSOLE_LOGLEVEL to 4 (same value as the 'quiet' kernel param)
# remove this when a Kconfig knob is made available by upstream
# (relevant patch sent upstream: https://lkml.org/lkml/2011/7/26/227)
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