Eric Lee / smarc-fsl-linux-kernel

12 Jan, 2020

1 commit

  • 16b730a45   fs: avoid softlockups in s_inodes iterators ... Browse Code »

    [ Upstream commit 04646aebd30b99f2cfa0182435a2ec252fcb16d0 ]

    Anything that walks all inodes on sb->s_inodes list without rescheduling
    risks softlockups.

    Previous efforts were made in 2 functions, see:

    c27d82f fs/drop_caches.c: avoid softlockups in drop_pagecache_sb()
    ac05fbb inode: don't softlockup when evicting inodes

    but there hasn't been an audit of all walkers, so do that now. This
    also consistently moves the cond_resched() calls to the bottom of each
    loop in cases where it already exists.

    One loop remains: remove_dquot_ref(), because I'm not quite sure how
    to deal with that one w/o taking the i_lock.

    Signed-off-by: Eric Sandeen
    Reviewed-by: Jan Kara
    Signed-off-by: Al Viro
    Signed-off-by: Sasha Levin

    Eric Sandeen
     

05 Jan, 2020

1 commit

  • 19f612e6c   fs/quota: handle overflows of sysctl fs.quota.* and report as unsigned long ... Browse Code »

    [ Upstream commit 6fcbcec9cfc7b3c6a2c1f1a23ebacedff7073e0a ]

    Quota statistics counted as 64-bit per-cpu counter. Reading sums per-cpu
    fractions as signed 64-bit int, filters negative values and then reports
    lower half as signed 32-bit int.

    Result may looks like:

    fs.quota.allocated_dquots = 22327
    fs.quota.cache_hits = -489852115
    fs.quota.drops = -487288718
    fs.quota.free_dquots = 22083
    fs.quota.lookups = -486883485
    fs.quota.reads = 22327
    fs.quota.syncs = 335064
    fs.quota.writes = 3088689

    Values bigger than 2^31-1 reported as negative.

    All counters except "allocated_dquots" and "free_dquots" are monotonic,
    thus they should be reported as is without filtering negative values.

    Kernel doesn't have generic helper for 64-bit sysctl yet,
    let's use at least unsigned long.

    Link: https://lore.kernel.org/r/157337934693.2078.9842146413181153727.stgit@buzz
    Signed-off-by: Konstantin Khlebnikov
    Signed-off-by: Jan Kara
    Signed-off-by: Sasha Levin

    Konstantin Khlebnikov
     

18 Dec, 2019

2 commits

  • 1a4437076   quota: fix livelock in dquot_writeback_dquots ... Browse Code »

    commit 6ff33d99fc5c96797103b48b7b0902c296f09c05 upstream.

    Write only quotas which are dirty at entry.

    XFSTEST: https://github.com/dmonakhov/xfstests/commit/b10ad23566a5bf75832a6f500e1236084083cddc

    Link: https://lore.kernel.org/r/20191031103920.3919-1-dmonakhov@openvz.org
    CC: stable@vger.kernel.org
    Signed-off-by: Konstantin Khlebnikov
    Signed-off-by: Dmitry Monakhov
    Signed-off-by: Jan Kara
    Signed-off-by: Greg Kroah-Hartman

    Dmitry Monakhov
     
  • b28df8395   quota: Check that quota is not dirty before release ... Browse Code »

    commit df4bb5d128e2c44848aeb36b7ceceba3ac85080d upstream.

    There is a race window where quota was redirted once we drop dq_list_lock inside dqput(),
    but before we grab dquot->dq_lock inside dquot_release()

    TASK1 TASK2 (chowner)
    ->dqput()
    we_slept:
    spin_lock(&dq_list_lock)
    if (dquot_dirty(dquot)) {
    spin_unlock(&dq_list_lock);
    dquot->dq_sb->dq_op->write_dquot(dquot);
    goto we_slept
    if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
    spin_unlock(&dq_list_lock);
    dquot->dq_sb->dq_op->release_dquot(dquot);
    dqget()
    mark_dquot_dirty()
    dqput()
    goto we_slept;
    }
    So dquot dirty quota will be released by TASK1, but on next we_sleept loop
    we detect this and call ->write_dquot() for it.
    XFSTEST: https://github.com/dmonakhov/xfstests/commit/440a80d4cbb39e9234df4d7240aee1d551c36107

    Link: https://lore.kernel.org/r/20191031103920.3919-2-dmonakhov@openvz.org
    CC: stable@vger.kernel.org
    Signed-off-by: Dmitry Monakhov
    Signed-off-by: Jan Kara
    Signed-off-by: Greg Kroah-Hartman

    Dmitry Monakhov
     

31 Jul, 2019

1 commit

11 Jul, 2019

1 commit

  • 682f7c5c4   Merge tag 'for_v5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs ... Browse Code »

    Pull ext2, udf and quota updates from Jan Kara:

    - some ext2 fixes and cleanups

    - a fix of udf bug when extending files

    - a fix of quota Q_XGETQSTAT[V] handling

    * tag 'for_v5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
    udf: Fix incorrect final NOT_ALLOCATED (hole) extent length
    ext2: Use kmemdup rather than duplicating its implementation
    quota: honor quota type in Q_XGETQSTAT[V] calls
    ext2: Always brelse bh on failure in ext2_iget()
    ext2: add missing brelse() in ext2_iget()
    ext2: Fix a typo in ext2_getattr argument
    ext2: fix a typo in comment
    ext2: add missing brelse() in ext2_new_inode()
    ext2: optimize ext2_xattr_get()
    ext2: introduce new helper for xattr entry comparison
    ext2: merge xattr next entry check to ext2_xattr_entry_valid()
    ext2: code cleanup for ext2_preread_inode()
    ext2: code cleanup by using test_opt() and clear_opt()
    doc: ext2: update description of quota options for ext2
    ext2: Strengthen xattr block checks
    ext2: Merge loops in ext2_xattr_set()
    ext2: introduce helper for xattr entry validation
    ext2: introduce helper for xattr header validation
    quota: add dqi_dirty_list description to comment of Dquot List Management

    Linus Torvalds
     

25 Jun, 2019

1 commit

  • 555b2c3da   quota: honor quota type in Q_XGETQSTAT[V] calls ... Browse Code »

    The code in quota_getstate and quota_getstatev is strange; it
    says the returned fs_quota_stat[v] structure has room for only
    one type of time limits, so fills it in with the first enabled
    quota, even though every quotactl command must have a type sent
    in by the user.

    Instead of just picking the first enabled quota, fill in the
    reply with the timers for the quota type that was actually
    requested.

    Reviewed-by: Christoph Hellwig
    Signed-off-by: Eric Sandeen
    Signed-off-by: Jan Kara

    Eric Sandeen
     

19 Jun, 2019

1 commit

  • c6d9c35d1   quota: fix a problem about transfer quota ... Browse Code »

    Run below script as root, dquot_add_space will return -EDQUOT since
    __dquot_transfer call dquot_add_space with flags=0, and dquot_add_space
    think it's a preallocation. Fix it by set flags as DQUOT_SPACE_WARN.

    mkfs.ext4 -O quota,project /dev/vdb
    mount -o prjquota /dev/vdb /mnt
    setquota -P 23 1 1 0 0 /dev/vdb
    dd if=/dev/zero of=/mnt/test-file bs=4K count=1
    chattr -p 23 test-file

    Fixes: 7b9ca4c61bc2 ("quota: Reduce contention on dq_data_lock")
    Signed-off-by: yangerkun
    Signed-off-by: Jan Kara

    yangerkun
     

21 May, 2019

2 commits

20 May, 2019

1 commit

01 May, 2019

1 commit

25 Apr, 2019

2 commits

  • 78bc3334a   fs/quota: erase unused but set variable warning ... Browse Code »

    Local variable *reserved* of remove_dquot_ref() is only used if
    define CONFIG_QUOTA_DEBUG, but not ebraced in CONFIG_QUOTA_DEBUG
    macro, which leads to unused-but-set-variable warning when compiling.

    This patch ebrace it into CONFIG_QUOTA_DEBUG macro like what is done
    in add_dquot_ref().

    Signed-off-by: Jiang Biao
    Signed-off-by: Jan Kara

    Jiang Biao
     
  • 3ef177ec9   quota: fix wrong indentation ... Browse Code »

    We need to check return code only when calling ->read_dqblk(),
    so fix it properly.

    Signed-off-by: Chengguang Xu
    Signed-off-by: Jan Kara

    Chengguang Xu
     

26 Mar, 2019

2 commits

19 Dec, 2018

1 commit

  • 41c4f85cd   quota: Lock s_umount in exclusive mode for Q_XQUOTA{ON,OFF} quotactls. ... Browse Code »

    Commit 1fa5efe3622db58cb8c7b9a50665e9eb9a6c7e97 (ext4: Use generic helpers for quotaon
    and quotaoff) made possible to call quotactl(Q_XQUOTAON/OFF) on ext4 filesystems
    with sysfile quota support. This leads to calling dquot_enable/disable without s_umount
    held in excl. mode, because quotactl_cmd_onoff checks only for Q_QUOTAON/OFF.

    The following WARN_ON_ONCE triggers (in this case for dquot_enable, ext4, latest Linus' tree):

    [ 117.807056] EXT4-fs (dm-0): mounted filesystem with ordered data mode. Opts: quota,prjquota

    [...]

    [ 155.036847] WARNING: CPU: 0 PID: 2343 at fs/quota/dquot.c:2469 dquot_enable+0x34/0xb9
    [ 155.036851] Modules linked in: quota_v2 quota_tree ipv6 af_packet joydev mousedev psmouse serio_raw pcspkr i2c_piix4 intel_agp intel_gtt e1000 ttm drm_kms_helper drm agpgart fb_sys_fops syscopyarea sysfillrect sysimgblt i2c_core input_leds kvm_intel kvm irqbypass qemu_fw_cfg floppy evdev parport_pc parport button crc32c_generic dm_mod ata_generic pata_acpi ata_piix libata loop ext4 crc16 mbcache jbd2 usb_storage usbcore sd_mod scsi_mod
    [ 155.036901] CPU: 0 PID: 2343 Comm: qctl Not tainted 4.20.0-rc6-00025-gf5d582777bcb #9
    [ 155.036903] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
    [ 155.036911] RIP: 0010:dquot_enable+0x34/0xb9
    [ 155.036915] Code: 41 56 41 55 41 54 55 53 4c 8b 6f 28 74 02 0f 0b 4d 8d 7d 70 49 89 fc 89 cb 41 89 d6 89 f5 4c 89 ff e8 23 09 ea ff 85 c0 74 0a 0b 4c 89 ff e8 8b 09 ea ff 85 db 74 6a 41 8b b5 f8 00 00 00 0f
    [ 155.036918] RSP: 0018:ffffb09b00493e08 EFLAGS: 00010202
    [ 155.036922] RAX: 0000000000000001 RBX: 0000000000000008 RCX: 0000000000000008
    [ 155.036924] RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff9781b67cd870
    [ 155.036926] RBP: 0000000000000002 R08: 0000000000000000 R09: 61c8864680b583eb
    [ 155.036929] R10: ffffb09b00493e48 R11: ffffffffff7ce7d4 R12: ffff9781b7ee8d78
    [ 155.036932] R13: ffff9781b67cd800 R14: 0000000000000004 R15: ffff9781b67cd870
    [ 155.036936] FS: 00007fd813250b88(0000) GS:ffff9781ba000000(0000) knlGS:0000000000000000
    [ 155.036939] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    [ 155.036942] CR2: 00007fd812ff61d6 CR3: 000000007c882000 CR4: 00000000000006b0
    [ 155.036951] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    [ 155.036953] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
    [ 155.036955] Call Trace:
    [ 155.037004] dquot_quota_enable+0x8b/0xd0
    [ 155.037011] kernel_quotactl+0x628/0x74e
    [ 155.037027] ? do_mprotect_pkey+0x2a6/0x2cd
    [ 155.037034] __x64_sys_quotactl+0x1a/0x1d
    [ 155.037041] do_syscall_64+0x55/0xe4
    [ 155.037078] entry_SYSCALL_64_after_hwframe+0x44/0xa9
    [ 155.037105] RIP: 0033:0x7fd812fe1198
    [ 155.037109] Code: 02 77 0d 48 89 c1 48 c1 e9 3f 75 04 48 8b 04 24 48 83 c4 50 5b c3 48 83 ec 08 49 89 ca 48 63 d2 48 63 ff b8 b3 00 00 00 0f 05 89 c7 e8 c1 eb ff ff 5a c3 48 63 ff b8 bb 00 00 00 0f 05 48 89
    [ 155.037112] RSP: 002b:00007ffe8cd7b050 EFLAGS: 00000206 ORIG_RAX: 00000000000000b3
    [ 155.037116] RAX: ffffffffffffffda RBX: 00007ffe8cd7b148 RCX: 00007fd812fe1198
    [ 155.037119] RDX: 0000000000000000 RSI: 00007ffe8cd7cea9 RDI: 0000000000580102
    [ 155.037121] RBP: 00007ffe8cd7b0f0 R08: 000055fc8eba8a9d R09: 0000000000000000
    [ 155.037124] R10: 00007ffe8cd7b074 R11: 0000000000000206 R12: 00007ffe8cd7b168
    [ 155.037126] R13: 000055fc8eba8897 R14: 0000000000000000 R15: 0000000000000000
    [ 155.037131] ---[ end trace 210f864257175c51 ]---

    and then the syscall proceeds without s_umount locking.

    This patch locks the superblock ->s_umount sem. in exclusive mode for all Q_XQUOTAON/OFF
    quotactls too in addition to Q_QUOTAON/OFF.

    AFAICT, other than ext4, only xfs and ocfs2 are affected by this change.
    The VFS will now call in xfs_quota_* functions with s_umount held, which wasn't the case
    before. This looks good to me but I can not say for sure. Ext4 and ocfs2 where already
    beeing called with s_umount exclusive via quota_quotaon/off which is basically the same.

    Signed-off-by: Javier Barrio
    Signed-off-by: Jan Kara

    Javier Barrio
     

23 Aug, 2018

2 commits

  • 7b6924d94   fs/quota: Fix spectre gadget in do_quotactl ... Browse Code »

    'type' is user-controlled, so sanitize it after the bounds check to
    avoid using it in speculative execution. This covers the following
    potential gadgets detected with the help of smatch:

    * fs/ext4/super.c:5741 ext4_quota_read() warn: potential spectre issue
    'sb_dqopt(sb)->files' [r]
    * fs/ext4/super.c:5778 ext4_quota_write() warn: potential spectre issue
    'sb_dqopt(sb)->files' [r]
    * fs/f2fs/super.c:1552 f2fs_quota_read() warn: potential spectre issue
    'sb_dqopt(sb)->files' [r]
    * fs/f2fs/super.c:1608 f2fs_quota_write() warn: potential spectre issue
    'sb_dqopt(sb)->files' [r]
    * fs/quota/dquot.c:412 mark_info_dirty() warn: potential spectre issue
    'sb_dqopt(sb)->info' [w]
    * fs/quota/dquot.c:933 dqinit_needed() warn: potential spectre issue
    'dquots' [r]
    * fs/quota/dquot.c:2112 dquot_commit_info() warn: potential spectre
    issue 'dqopt->ops' [r]
    * fs/quota/dquot.c:2362 vfs_load_quota_inode() warn: potential spectre
    issue 'dqopt->files' [w] (local cap)
    * fs/quota/dquot.c:2369 vfs_load_quota_inode() warn: potential spectre
    issue 'dqopt->ops' [w] (local cap)
    * fs/quota/dquot.c:2370 vfs_load_quota_inode() warn: potential spectre
    issue 'dqopt->info' [w] (local cap)
    * fs/quota/quota.c:110 quota_getfmt() warn: potential spectre issue
    'sb_dqopt(sb)->info' [r]
    * fs/quota/quota_v2.c:84 v2_check_quota_file() warn: potential spectre
    issue 'quota_magics' [w]
    * fs/quota/quota_v2.c:85 v2_check_quota_file() warn: potential spectre
    issue 'quota_versions' [w]
    * fs/quota/quota_v2.c:96 v2_read_file_info() warn: potential spectre
    issue 'dqopt->info' [r]
    * fs/quota/quota_v2.c:172 v2_write_file_info() warn: potential spectre
    issue 'dqopt->info' [r]

    Additionally, a quick inspection indicates there are array accesses with
    'type' in quota_on() and quota_off() functions which are also addressed
    by this.

    Cc: Josh Poimboeuf
    Cc: stable@vger.kernel.org
    Signed-off-by: Jeremy Cline
    Signed-off-by: Jan Kara

    Jeremy Cline
     
  • 64d9d1382   fs/quota: Replace XQM_MAXQUOTAS usage with MAXQUOTAS ... Browse Code »

    XQM_MAXQUOTAS and MAXQUOTAS are, it appears, equivalent. Replace all
    usage of XQM_MAXQUOTAS and remove it along with the unused XQM_*QUOTA
    definitions.

    Signed-off-by: Jeremy Cline
    Signed-off-by: Jan Kara

    Jeremy Cline
     

20 Jun, 2018

2 commits

09 Apr, 2018

1 commit

  • 1aa3b3e0c   fs: quota: Replace GFP_ATOMIC with GFP_KERNEL in dquot_init ... Browse Code »

    dquot_init() is never called in atomic context.
    This function is only set as a parameter of fs_initcall().

    Despite never getting called from atomic context,
    dquot_init() calls __get_free_pages() with GFP_ATOMIC,
    which waits busily for allocation.
    GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
    to avoid busy waiting and improve the possibility of sucessful allocation.

    This is found by a static analysis tool named DCNS written by myself.
    And I also manually check it.

    Signed-off-by: Jia-Ju Bai
    Signed-off-by: Jan Kara

    Jia-Ju Bai
     

03 Apr, 2018

2 commits

29 Nov, 2017

1 commit

  • 88bc0ede8   quota: Check for register_shrinker() failure. ... Browse Code »

    register_shrinker() might return -ENOMEM error since Linux 3.12.
    Call panic() as with other failure checks in this function if
    register_shrinker() failed.

    Fixes: 1d3d4437eae1 ("vmscan: per-node deferred work")
    Signed-off-by: Tetsuo Handa
    Cc: Jan Kara
    Cc: Michal Hocko
    Reviewed-by: Michal Hocko
    Signed-off-by: Jan Kara

    Tetsuo Handa
     

28 Nov, 2017

1 commit

  • 1a6152d36   quota: propagate error from __dquot_initialize ... Browse Code »

    In commit 6184fc0b8dd7 ("quota: Propagate error from ->acquire_dquot()"),
    we have propagated error from __dquot_initialize to caller, but we forgot
    to handle such error in add_dquot_ref(), so, currently, during quota
    accounting information initialization flow, if we failed for some of
    inodes, we just ignore such error, and do account for others, which is
    not a good implementation.

    In this patch, we choose to let user be aware of such error, so after
    turning on quota successfully, we can make sure all inodes disk usage
    can be accounted, which will be more reasonable.

    Suggested-by: Jan Kara
    Signed-off-by: Chao Yu
    Signed-off-by: Jan Kara

    Chao Yu
     

15 Nov, 2017

1 commit

  • f14fc0cce   Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs ... Browse Code »

    Pull quota, ext2, isofs and udf fixes from Jan Kara:

    - two small quota error handling fixes

    - two isofs fixes for architectures with signed char

    - several udf block number overflow and signedness fixes

    - ext2 rework of mount option handling to avoid GFP_KERNEL allocation
    with spinlock held

    - ... it also contains a patch to implement auditing of responses to
    fanotify permission events. That should have been in the fanotify
    pull request but I mistakenly merged that patch into a wrong branch
    and noticed only now at which point I don't think it's worth rebasing
    and redoing.

    * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
    quota: be aware of error from dquot_initialize
    quota: fix potential infinite loop
    isofs: use unsigned char types consistently
    isofs: fix timestamps beyond 2027
    udf: Fix some sign-conversion warnings
    udf: Fix signed/unsigned format specifiers
    udf: Fix 64-bit sign extension issues affecting blocks > 0x7FFFFFFF
    udf: Remove some outdate references from documentation
    udf: Avoid overflow when session starts at large offset
    ext2: Fix possible sleep in atomic during mount option parsing
    ext2: Parse mount options into a dedicated structure
    audit: Record fanotify access control decisions

    Linus Torvalds
     

14 Nov, 2017

1 commit

13 Nov, 2017

1 commit

02 Nov, 2017

1 commit

  • b24413180   License cleanup: add SPDX GPL-2.0 license identifier to files with no license ... Browse Code »

    Many source files in the tree are missing licensing information, which
    makes it harder for compliance tools to determine the correct license.

    By default all files without license information are under the default
    license of the kernel, which is GPL version 2.

    Update the files which contain no license information with the 'GPL-2.0'
    SPDX license identifier. The SPDX identifier is a legally binding
    shorthand, which can be used instead of the full boiler plate text.

    This patch is based on work done by Thomas Gleixner and Kate Stewart and
    Philippe Ombredanne.

    How this work was done:

    Patches were generated and checked against linux-4.14-rc6 for a subset of
    the use cases:
    - file had no licensing information it it.
    - file was a */uapi/* one with no licensing information in it,
    - file was a */uapi/* one with existing licensing information,

    Further patches will be generated in subsequent months to fix up cases
    where non-standard license headers were used, and references to license
    had to be inferred by heuristics based on keywords.

    The analysis to determine which SPDX License Identifier to be applied to
    a file was done in a spreadsheet of side by side results from of the
    output of two independent scanners (ScanCode & Windriver) producing SPDX
    tag:value files created by Philippe Ombredanne. Philippe prepared the
    base worksheet, and did an initial spot review of a few 1000 files.

    The 4.13 kernel was the starting point of the analysis with 60,537 files
    assessed. Kate Stewart did a file by file comparison of the scanner
    results in the spreadsheet to determine which SPDX license identifier(s)
    to be applied to the file. She confirmed any determination that was not
    immediately clear with lawyers working with the Linux Foundation.

    Criteria used to select files for SPDX license identifier tagging was:
    - Files considered eligible had to be source code files.
    - Make and config files were included as candidates if they contained >5
    lines of source
    - File already had some variant of a license header in it (even if
    Reviewed-by: Philippe Ombredanne
    Reviewed-by: Thomas Gleixner
    Signed-off-by: Greg Kroah-Hartman

    Greg Kroah-Hartman
     

01 Nov, 2017

1 commit

  • dd5f62797   quota: fix potential infinite loop ... Browse Code »

    In dquot_writeback_dquots(), we write back dquot from dirty dquots
    list. There is a potential infinite loop if ->write_dquot() failure
    and forget remove dquot from the list. This patch clear dirty bit
    anyway to avoid it.

    Signed-off-by: zhangyi (F)
    Signed-off-by: Jan Kara

    zhangyi (F)
     

10 Oct, 2017

1 commit

  • ac3d79392   quota: Generate warnings for DQUOT_SPACE_NOFAIL allocations ... Browse Code »

    Eryu has reported that since commit 7b9ca4c61bc2 "quota: Reduce
    contention on dq_data_lock" test generic/233 occasionally fails. This is
    caused by the fact that since that commit we don't generate warning and
    set grace time for quota allocations that have DQUOT_SPACE_NOFAIL set
    (these are for example some metadata allocations in ext4). We need these
    allocations to behave regularly wrt warning generation and grace time
    setting so fix the code to return to the original behavior.

    Reported-and-tested-by: Eryu Guan
    CC: stable@vger.kernel.org
    Fixes: 7b9ca4c61bc278b771fb57d6290a31ab1fc7fdac
    Signed-off-by: Jan Kara

    Jan Kara
     

27 Sep, 2017

1 commit

  • 4c6bb6966   quota: Fix quota corruption with generic/232 test ... Browse Code »

    Eric has reported that since commit d2faa415166b "quota: Do not acquire
    dqio_sem for dquot overwrites in v2 format" test generic/232
    occasionally fails due to quota information being incorrect. Indeed that
    commit was too eager to remove dqio_sem completely from the path that
    just overwrites quota structure with updated information. Although that
    is innocent on its own, another process that inserts new quota structure
    to the same block can perform read-modify-write cycle of that block thus
    effectively discarding quota information update if they race in a wrong
    way.

    Fix the problem by acquiring dqio_sem for reading for overwrites of
    quota structure. Note that it *is* possible to completely avoid taking
    dqio_sem in the overwrite path however that will require modifying path
    inserting / deleting quota structures to avoid RMW cycles of the full
    block and for now it is not clear whether it is worth the hassle.

    Fixes: d2faa415166b2883428efa92f451774ef44373ac
    Reported-and-tested-by: Eric Whitney
    Signed-off-by: Jan Kara

    Jan Kara
     

18 Sep, 2017

1 commit

15 Sep, 2017

1 commit

  • 0f0d12728   Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs ... Browse Code »

    Pull mount flag updates from Al Viro:
    "Another chunk of fmount preparations from dhowells; only trivial
    conflicts for that part. It separates MS_... bits (very grotty
    mount(2) ABI) from the struct super_block ->s_flags (kernel-internal,
    only a small subset of MS_... stuff).

    This does *not* convert the filesystems to new constants; only the
    infrastructure is done here. The next step in that series is where the
    conflicts would be; that's the conversion of filesystems. It's purely
    mechanical and it's better done after the merge, so if you could run
    something like

    list=$(for i in MS_RDONLY MS_NOSUID MS_NODEV MS_NOEXEC MS_SYNCHRONOUS MS_MANDLOCK MS_DIRSYNC MS_NOATIME MS_NODIRATIME MS_SILENT MS_POSIXACL MS_KERNMOUNT MS_I_VERSION MS_LAZYTIME; do git grep -l $i fs drivers/staging/lustre drivers/mtd ipc mm include/linux; done|sort|uniq|grep -v '^fs/namespace.c$')

    sed -i -e 's/\/SB_RDONLY/g' \
    -e 's/\/SB_NOSUID/g' \
    -e 's/\/SB_NODEV/g' \
    -e 's/\/SB_NOEXEC/g' \
    -e 's/\/SB_SYNCHRONOUS/g' \
    -e 's/\/SB_MANDLOCK/g' \
    -e 's/\/SB_DIRSYNC/g' \
    -e 's/\/SB_NOATIME/g' \
    -e 's/\/SB_NODIRATIME/g' \
    -e 's/\/SB_SILENT/g' \
    -e 's/\/SB_POSIXACL/g' \
    -e 's/\/SB_KERNMOUNT/g' \
    -e 's/\/SB_I_VERSION/g' \
    -e 's/\/SB_LAZYTIME/g' \
    $list

    and commit it with something along the lines of 'convert filesystems
    away from use of MS_... constants' as commit message, it would save a
    quite a bit of headache next cycle"

    * 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
    VFS: Differentiate mount flags (MS_*) from internal superblock flags
    VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb)
    vfs: Add sb_rdonly(sb) to query the MS_RDONLY flag on s_flags

    Linus Torvalds
     

08 Sep, 2017

1 commit

  • ae8ac6b7d   Merge branch 'quota_scaling' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs ... Browse Code »

    Pull quota scaling updates from Jan Kara:
    "This contains changes to make the quota subsystem more scalable.

    Reportedly it improves number of files created per second on ext4
    filesystem on fast storage by about a factor of 2x"

    * 'quota_scaling' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: (28 commits)
    quota: Add lock annotations to struct members
    quota: Reduce contention on dq_data_lock
    fs: Provide __inode_get_bytes()
    quota: Inline dquot_[re]claim_reserved_space() into callsite
    quota: Inline inode_{incr,decr}_space() into callsites
    quota: Inline functions into their callsites
    ext4: Disable dirty list tracking of dquots when journalling quotas
    quota: Allow disabling tracking of dirty dquots in a list
    quota: Remove dq_wait_unused from dquot
    quota: Move locking into clear_dquot_dirty()
    quota: Do not dirty bad dquots
    quota: Fix possible corruption of dqi_flags
    quota: Propagate ->quota_read errors from v2_read_file_info()
    quota: Fix error codes in v2_read_file_info()
    quota: Push dqio_sem down to ->read_file_info()
    quota: Push dqio_sem down to ->write_file_info()
    quota: Push dqio_sem down to ->get_next_id()
    quota: Push dqio_sem down to ->release_dqblk()
    quota: Remove locking for writing to the old quota format
    quota: Do not acquire dqio_sem for dquot overwrites in v2 format
    ...

    Linus Torvalds
     

21 Aug, 2017

1 commit

18 Aug, 2017

3 commits

  • 7b9ca4c61   quota: Reduce contention on dq_data_lock ... Browse Code »

    dq_data_lock is currently used to protect all modifications of quota
    accounting information, consistency of quota accounting on the inode,
    and dquot pointers from inode. As a result contention on the lock can be
    pretty heavy.

    Reduce the contention on the lock by protecting quota accounting
    information by a new dquot->dq_dqb_lock and consistency of quota
    accounting with inode usage by inode->i_lock.

    This change reduces time to create 500000 files on ext4 on ramdisk by 50
    different processes in separate directories by 6% when user quota is
    turned on. When those 50 processes belong to 50 different users, the
    improvement is about 9%.

    Signed-off-by: Jan Kara

    Jan Kara
     
  • 3ab167d2b   quota: Inline dquot_[re]claim_reserved_space() into callsite ... Browse Code »

    dquot_claim_reserved_space() and dquot_reclaim_reserved_space() have
    only a single callsite. Inline them there.

    Signed-off-by: Jan Kara

    Jan Kara
     
  • a478e522e   quota: Inline inode_{incr,decr}_space() into callsites ... Browse Code »

    inode_incr_space() and inode_decr_space() have only two callsites.
    Inline them there as that will make locking changes simpler.

    Signed-off-by: Jan Kara

    Jan Kara