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Anand Jain b4a4c9dc44 btrfs: call btrfs_check_rw_degradable only if there is a missing device
commit 5c78a5e7aa upstream.

In open_ctree() in btrfs_check_rw_degradable() [1], we check each block
group individually if at least the minimum number of devices is available
for that profile. If all the devices are available, then we don't have to
check degradable.

[1]
open_ctree()
::
3559 if (!sb_rdonly(sb) && !btrfs_check_rw_degradable(fs_info, NULL)) {

Also before calling btrfs_check_rw_degradable() in open_ctee() at the
line number shown below [2] we call btrfs_read_chunk_tree() and down to
add_missing_dev() to record number of missing devices.

[2]
open_ctree()
::
3454         ret = btrfs_read_chunk_tree(fs_info);

btrfs_read_chunk_tree()
  read_one_chunk() / read_one_dev()
    add_missing_dev()

So, check if there is any missing device before btrfs_check_rw_degradable()
in open_ctree().

Also, with this the mount command could save ~16ms.[3] in the most
common case, that is no device is missing.

[3]
 1) * 16934.96 us | btrfs_check_rw_degradable [btrfs]();

CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-18 14:03:44 +01:00
arch bpf: Define bpf_jit_alloc_exec_limit for arm64 JIT 2021-11-18 14:03:42 +01:00
block block: schedule queue restart after BLK_STS_ZONE_RESOURCE 2021-11-18 14:03:43 +01:00
certs certs: Trigger creation of RSA module signing key if it's not an RSA key 2021-09-15 09:50:29 +02:00
crypto crypto: sm2 - fix a memory leak in sm2 2021-07-14 16:56:06 +02:00
Documentation dt-bindings: drm/bridge: ti-sn65dsi86: Fix reg value 2021-10-13 10:04:27 +02:00
drivers nfp: bpf: relax prog rejection for mtu check through max_pkt_offset 2021-11-18 14:03:43 +01:00
fs btrfs: call btrfs_check_rw_degradable only if there is a missing device 2021-11-18 14:03:44 +01:00
include net: multicast: calculate csum of looped-back and forwarded packets 2021-11-18 14:03:43 +01:00
init sched/core: Initialize the idle task with preemption disabled 2021-07-14 16:55:50 +02:00
ipc ipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry 2021-05-26 12:06:54 +02:00
kernel bpf: Prevent increasing bpf_jit_limit above max 2021-11-18 14:03:42 +01:00
lib treewide: Change list_sort to use const pointers 2021-09-30 10:11:04 +02:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm: khugepaged: skip huge page collapse for special files 2021-11-06 14:10:09 +01:00
net rds: stop using dmapool 2021-11-18 14:03:44 +01:00
samples samples: bpf: Fix tracex7 error raised on the missing argument 2021-09-18 13:40:23 +02:00
scripts gcc-plugins/structleak: add makefile var for disabling structleak 2021-10-27 09:56:54 +02:00
security binder: use cred instead of task for selinux checks 2021-11-18 14:03:36 +01:00
sound ALSA: hda/realtek: Fixes HP Spectre x360 15-eb1xxx speakers 2021-11-18 14:03:41 +01:00
tools fcnal-test: kill hanging ping/nettest binaries on cleanup 2021-11-18 14:03:42 +01:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt KVM: do not shrink halt_poll_ns below grow_start 2021-10-09 14:40:58 +02:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: generate Module.symvers only when vmlinux exists 2021-05-19 10:12:59 +02:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS f2fs: move ioctl interface definitions to separated file 2021-05-19 10:13:00 +02:00
Makefile Linux 5.10.79 2021-11-12 14:58:35 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.