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Qu Wenruo dcedd37957 btrfs: qgroup: Make qgroup async transaction commit more aggressive
[ Upstream commit f5fef45936 ]

[BUG]
Btrfs qgroup will still hit EDQUOT under the following case:

  $ dev=/dev/test/test
  $ mnt=/mnt/btrfs
  $ umount $mnt &> /dev/null
  $ umount $dev &> /dev/null

  $ mkfs.btrfs -f $dev
  $ mount $dev $mnt -o nospace_cache

  $ btrfs subv create $mnt/subv
  $ btrfs quota enable $mnt
  $ btrfs quota rescan -w $mnt
  $ btrfs qgroup limit -e 1G $mnt/subv

  $ fallocate -l 900M $mnt/subv/padding
  $ sync

  $ rm $mnt/subv/padding

  # Hit EDQUOT
  $ xfs_io -f -c "pwrite 0 512M" $mnt/subv/real_file

[CAUSE]
Since commit a514d63882 ("btrfs: qgroup: Commit transaction in advance
to reduce early EDQUOT"), btrfs is not forced to commit transaction to
reclaim more quota space.

Instead, we just check pertrans metadata reservation against some
threshold and try to do asynchronously transaction commit.

However in above case, the pertrans metadata reservation is pretty small
thus it will never trigger asynchronous transaction commit.

[FIX]
Instead of only accounting pertrans metadata reservation, we calculate
how much free space we have, and if there isn't much free space left,
commit transaction asynchronously to try to free some space.

This may slow down the fs when we have less than 32M free qgroup space,
but should reduce a lot of false EDQUOT, so the cost should be
acceptable.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-05 22:33:02 +02:00
arch powerpc/hugetlb: Handle mmap_min_addr correctly in get_unmapped_area callback 2019-04-05 22:33:02 +02:00
block blk-mq: insert rq with DONTPREP to hctx dispatch list when requeue 2019-03-23 20:09:45 +01:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto crypto: testmgr - skip crc32c context test for ahash algorithms 2019-03-23 20:09:55 +01:00
Documentation KVM: Reject device ioctls from processes other than the VM's creator 2019-04-03 06:26:29 +02:00
drivers iommu/io-pgtable-arm-v7s: Only kmemleak_ignore L2 tables 2019-04-05 22:33:02 +02:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs btrfs: qgroup: Make qgroup async transaction commit more aggressive 2019-04-05 22:33:02 +02:00
include f2fs: fix to check inline_xattr_size boundary correctly 2019-04-05 22:32:59 +02:00
init Revert "mm: use early_pfn_to_nid in page_ext_init" 2019-03-23 20:09:46 +01:00
ipc ipc/shm.c: use ERR_CAST() for shm_lock() error return 2018-10-05 16:32:04 -07:00
kernel sysctl: handle overflow for file-max 2019-04-05 22:32:57 +02:00
lib rhashtable: Still do rehash when we get EEXIST 2019-04-03 06:26:17 +02:00
LICENSES LICENSES: Remove CC-BY-SA-4.0 license text 2018-10-18 11:28:50 +02:00
mm page_poison: play nicely with KASAN 2019-04-05 22:32:59 +02:00
net netfilter: conntrack: tcp: only close if RST matches exact sequence 2019-04-05 22:33:00 +02:00
samples samples: mei: use /dev/mei0 instead of /dev/mei 2019-02-15 08:10:11 +01:00
scripts kbuild: modversions: Fix relative CRC byte order interpretation 2019-04-03 06:26:23 +02:00
security security/selinux: fix SECURITY_LSM_NATIVE_LABELS on reused superblock 2019-03-23 20:10:06 +01:00
sound ALSA: hda/realtek - Fix speakers on Acer Predator Helios 500 Ryzen laptops 2019-04-03 06:26:23 +02:00
tools tools lib traceevent: Fix buffer overflow in arg_eval 2019-04-05 22:33:00 +02:00
usr initramfs: move gen_initramfs_list.sh from scripts/ to usr/ 2018-08-22 23:21:44 +09:00
virt KVM: Reject device ioctls from processes other than the VM's creator 2019-04-03 06:26:29 +02:00
.clang-format clang-format: Set IndentWrappedFunctionNames false 2018-08-01 18:38:51 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap libnvdimm-for-4.19_misc 2018-08-25 18:13:10 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS 9p: remove Ron Minnich from MAINTAINERS 2018-08-17 16:20:26 -07:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS MAINTAINERS: Add Sasha as a stable branch maintainer 2018-12-01 09:37:25 +01:00
Makefile kbuild: invoke syncconfig if include/config/auto.conf.cmd is missing 2019-04-05 22:33:01 +02:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -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.
See Documentation/00-INDEX for a list of what is contained in each file.

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.