03 Aug, 2016

2 commits

  • Replace bit shifts by BIT macro for clarity.

    Link: http://lkml.kernel.org/r/1465825507-3407-3-git-send-email-konishi.ryusuke@lab.ntt.co.jp
    Signed-off-by: Ryusuke Konishi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ryusuke Konishi
     
  • Use nilfs_msg() to output warning messages and get rid of
    nilfs_warning() function. This also removes function names from the
    messages unless we embed them explicitly in format strings. Instead,
    some messages are revised to clarify the context.

    [arnd@arndb.de: avoid warning about unused variables]
    Link: http://lkml.kernel.org/r/20160615201945.3348205-1-arnd@arndb.de
    Link: http://lkml.kernel.org/r/1464875891-5443-6-git-send-email-konishi.ryusuke@lab.ntt.co.jp
    Signed-off-by: Ryusuke Konishi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ryusuke Konishi
     

24 May, 2016

3 commits

  • This fixes checkpatch.pl warning "WARNING: Prefer 'unsigned int' to
    bare use of 'unsigned'".

    Link: http://lkml.kernel.org/r/1462886671-3521-5-git-send-email-konishi.ryusuke@lab.ntt.co.jp
    Signed-off-by: Ryusuke Konishi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ryusuke Konishi
     
  • E-mail addresses of osrg.net domain are no longer available. This
    removes them from authorship notices and prevents reporters from being
    confused.

    Link: http://lkml.kernel.org/r/1461935747-10380-5-git-send-email-konishi.ryusuke@lab.ntt.co.jp
    Signed-off-by: Ryusuke Konishi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ryusuke Konishi
     
  • This removes the extra paragraph which mentions FSF address in GPL
    notices from source code of nilfs2 and avoids the checkpatch.pl error
    related to it.

    Link: http://lkml.kernel.org/r/1461935747-10380-4-git-send-email-konishi.ryusuke@lab.ntt.co.jp
    Signed-off-by: Ryusuke Konishi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ryusuke Konishi
     

05 Apr, 2016

1 commit

  • PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
    ago with promise that one day it will be possible to implement page
    cache with bigger chunks than PAGE_SIZE.

    This promise never materialized. And unlikely will.

    We have many places where PAGE_CACHE_SIZE assumed to be equal to
    PAGE_SIZE. And it's constant source of confusion on whether
    PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
    especially on the border between fs and mm.

    Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
    breakage to be doable.

    Let's stop pretending that pages in page cache are special. They are
    not.

    The changes are pretty straight-forward:

    - << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ;

    - >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ;

    - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

    - page_cache_get() -> get_page();

    - page_cache_release() -> put_page();

    This patch contains automated changes generated with coccinelle using
    script below. For some reason, coccinelle doesn't patch header files.
    I've called spatch for them manually.

    The only adjustment after coccinelle is revert of changes to
    PAGE_CAHCE_ALIGN definition: we are going to drop it later.

    There are few places in the code where coccinelle didn't reach. I'll
    fix them manually in a separate patch. Comments and documentation also
    will be addressed with the separate patch.

    virtual patch

    @@
    expression E;
    @@
    - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
    + E

    @@
    expression E;
    @@
    - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
    + E

    @@
    @@
    - PAGE_CACHE_SHIFT
    + PAGE_SHIFT

    @@
    @@
    - PAGE_CACHE_SIZE
    + PAGE_SIZE

    @@
    @@
    - PAGE_CACHE_MASK
    + PAGE_MASK

    @@
    expression E;
    @@
    - PAGE_CACHE_ALIGN(E)
    + PAGE_ALIGN(E)

    @@
    expression E;
    @@
    - page_cache_get(E)
    + get_page(E)

    @@
    expression E;
    @@
    - page_cache_release(E)
    + put_page(E)

    Signed-off-by: Kirill A. Shutemov
    Acked-by: Michal Hocko
    Signed-off-by: Linus Torvalds

    Kirill A. Shutemov
     

18 Mar, 2016

1 commit

  • The success of CMA allocation largely depends on the success of
    migration and key factor of it is page reference count. Until now, page
    reference is manipulated by direct calling atomic functions so we cannot
    follow up who and where manipulate it. Then, it is hard to find actual
    reason of CMA allocation failure. CMA allocation should be guaranteed
    to succeed so finding offending place is really important.

    In this patch, call sites where page reference is manipulated are
    converted to introduced wrapper function. This is preparation step to
    add tracepoint to each page reference manipulation function. With this
    facility, we can easily find reason of CMA allocation failure. There is
    no functional change in this patch.

    In addition, this patch also converts reference read sites. It will
    help a second step that renames page._count to something else and
    prevents later attempt to direct access to it (Suggested by Andrew).

    Signed-off-by: Joonsoo Kim
    Acked-by: Michal Nazarewicz
    Acked-by: Vlastimil Babka
    Cc: Minchan Kim
    Cc: Mel Gorman
    Cc: "Kirill A. Shutemov"
    Cc: Sergey Senozhatsky
    Cc: Steven Rostedt
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Joonsoo Kim
     

17 Apr, 2015

1 commit


21 Jan, 2015

1 commit

  • Now that we never use the backing_dev_info pointer in struct address_space
    we can simply remove it and save 4 to 8 bytes in every inode.

    Signed-off-by: Christoph Hellwig
    Acked-by: Ryusuke Konishi
    Reviewed-by: Tejun Heo
    Reviewed-by: Jan Kara
    Signed-off-by: Jens Axboe

    Christoph Hellwig
     

01 Oct, 2013

1 commit

  • Many NILFS2 users were reported about strange file system corruption
    (for example):

    NILFS: bad btree node (blocknr=185027): level = 0, flags = 0x0, nchildren = 768
    NILFS error (device sda4): nilfs_bmap_last_key: broken bmap (inode number=11540)

    But such error messages are consequence of file system's issue that takes
    place more earlier. Fortunately, Jerome Poulin
    and Anton Eliasson were reported about another
    issue not so recently. These reports describe the issue with segctor
    thread's crash:

    BUG: unable to handle kernel paging request at 0000000000004c83
    IP: nilfs_end_page_io+0x12/0xd0 [nilfs2]

    Call Trace:
    nilfs_segctor_do_construct+0xf25/0x1b20 [nilfs2]
    nilfs_segctor_construct+0x17b/0x290 [nilfs2]
    nilfs_segctor_thread+0x122/0x3b0 [nilfs2]
    kthread+0xc0/0xd0
    ret_from_fork+0x7c/0xb0

    These two issues have one reason. This reason can raise third issue
    too. Third issue results in hanging of segctor thread with eating of
    100% CPU.

    REPRODUCING PATH:

    One of the possible way or the issue reproducing was described by
    Jermoe me Poulin :

    1. init S to get to single user mode.
    2. sysrq+E to make sure only my shell is running
    3. start network-manager to get my wifi connection up
    4. login as root and launch "screen"
    5. cd /boot/log/nilfs which is a ext3 mount point and can log when NILFS dies.
    6. lscp | xz -9e > lscp.txt.xz
    7. mount my snapshot using mount -o cp=3360839,ro /dev/vgUbuntu/root /mnt/nilfs
    8. start a screen to dump /proc/kmsg to text file since rsyslog is killed
    9. start a screen and launch strace -f -o find-cat.log -t find
    /mnt/nilfs -type f -exec cat {} > /dev/null \;
    10. start a screen and launch strace -f -o apt-get.log -t apt-get update
    11. launch the last command again as it did not crash the first time
    12. apt-get crashes
    13. ps aux > ps-aux-crashed.log
    13. sysrq+W
    14. sysrq+E wait for everything to terminate
    15. sysrq+SUSB

    Simplified way of the issue reproducing is starting kernel compilation
    task and "apt-get update" in parallel.

    REPRODUCIBILITY:

    The issue is reproduced not stable [60% - 80%]. It is very important to
    have proper environment for the issue reproducing. The critical
    conditions for successful reproducing:

    (1) It should have big modified file by mmap() way.

    (2) This file should have the count of dirty blocks are greater that
    several segments in size (for example, two or three) from time to time
    during processing.

    (3) It should be intensive background activity of files modification
    in another thread.

    INVESTIGATION:

    First of all, it is possible to see that the reason of crash is not valid
    page address:

    NILFS [nilfs_segctor_complete_write]:2100 bh->b_count 0, bh->b_blocknr 13895680, bh->b_size 13897727, bh->b_page 0000000000001a82
    NILFS [nilfs_segctor_complete_write]:2101 segbuf->sb_segnum 6783

    Moreover, value of b_page (0x1a82) is 6786. This value looks like segment
    number. And b_blocknr with b_size values look like block numbers. So,
    buffer_head's pointer points on not proper address value.

    Detailed investigation of the issue is discovered such picture:

    [-----------------------------SEGMENT 6783-------------------------------]
    NILFS [nilfs_segctor_do_construct]:2310 nilfs_segctor_begin_construction
    NILFS [nilfs_segctor_do_construct]:2321 nilfs_segctor_collect
    NILFS [nilfs_segctor_do_construct]:2336 nilfs_segctor_assign
    NILFS [nilfs_segctor_do_construct]:2367 nilfs_segctor_update_segusage
    NILFS [nilfs_segctor_do_construct]:2371 nilfs_segctor_prepare_write
    NILFS [nilfs_segctor_do_construct]:2376 nilfs_add_checksums_on_logs
    NILFS [nilfs_segctor_do_construct]:2381 nilfs_segctor_write
    NILFS [nilfs_segbuf_submit_bio]:464 bio->bi_sector 111149024, segbuf->sb_segnum 6783

    [-----------------------------SEGMENT 6784-------------------------------]
    NILFS [nilfs_segctor_do_construct]:2310 nilfs_segctor_begin_construction
    NILFS [nilfs_segctor_do_construct]:2321 nilfs_segctor_collect
    NILFS [nilfs_lookup_dirty_data_buffers]:782 bh->b_count 1, bh->b_page ffffea000709b000, page->index 0, i_ino 1033103, i_size 25165824
    NILFS [nilfs_lookup_dirty_data_buffers]:783 bh->b_assoc_buffers.next ffff8802174a6798, bh->b_assoc_buffers.prev ffff880221cffee8
    NILFS [nilfs_segctor_do_construct]:2336 nilfs_segctor_assign
    NILFS [nilfs_segctor_do_construct]:2367 nilfs_segctor_update_segusage
    NILFS [nilfs_segctor_do_construct]:2371 nilfs_segctor_prepare_write
    NILFS [nilfs_segctor_do_construct]:2376 nilfs_add_checksums_on_logs
    NILFS [nilfs_segctor_do_construct]:2381 nilfs_segctor_write
    NILFS [nilfs_segbuf_submit_bh]:575 bh->b_count 1, bh->b_page ffffea000709b000, page->index 0, i_ino 1033103, i_size 25165824
    NILFS [nilfs_segbuf_submit_bh]:576 segbuf->sb_segnum 6784
    NILFS [nilfs_segbuf_submit_bh]:577 bh->b_assoc_buffers.next ffff880218a0d5f8, bh->b_assoc_buffers.prev ffff880218bcdf50
    NILFS [nilfs_segbuf_submit_bio]:464 bio->bi_sector 111150080, segbuf->sb_segnum 6784, segbuf->sb_nbio 0
    [----------] ditto
    NILFS [nilfs_segbuf_submit_bio]:464 bio->bi_sector 111164416, segbuf->sb_segnum 6784, segbuf->sb_nbio 15

    [-----------------------------SEGMENT 6785-------------------------------]
    NILFS [nilfs_segctor_do_construct]:2310 nilfs_segctor_begin_construction
    NILFS [nilfs_segctor_do_construct]:2321 nilfs_segctor_collect
    NILFS [nilfs_lookup_dirty_data_buffers]:782 bh->b_count 2, bh->b_page ffffea000709b000, page->index 0, i_ino 1033103, i_size 25165824
    NILFS [nilfs_lookup_dirty_data_buffers]:783 bh->b_assoc_buffers.next ffff880219277e80, bh->b_assoc_buffers.prev ffff880221cffc88
    NILFS [nilfs_segctor_do_construct]:2367 nilfs_segctor_update_segusage
    NILFS [nilfs_segctor_do_construct]:2371 nilfs_segctor_prepare_write
    NILFS [nilfs_segctor_do_construct]:2376 nilfs_add_checksums_on_logs
    NILFS [nilfs_segctor_do_construct]:2381 nilfs_segctor_write
    NILFS [nilfs_segbuf_submit_bh]:575 bh->b_count 2, bh->b_page ffffea000709b000, page->index 0, i_ino 1033103, i_size 25165824
    NILFS [nilfs_segbuf_submit_bh]:576 segbuf->sb_segnum 6785
    NILFS [nilfs_segbuf_submit_bh]:577 bh->b_assoc_buffers.next ffff880218a0d5f8, bh->b_assoc_buffers.prev ffff880222cc7ee8
    NILFS [nilfs_segbuf_submit_bio]:464 bio->bi_sector 111165440, segbuf->sb_segnum 6785, segbuf->sb_nbio 0
    [----------] ditto
    NILFS [nilfs_segbuf_submit_bio]:464 bio->bi_sector 111177728, segbuf->sb_segnum 6785, segbuf->sb_nbio 12

    NILFS [nilfs_segctor_do_construct]:2399 nilfs_segctor_wait
    NILFS [nilfs_segbuf_wait]:676 segbuf->sb_segnum 6783
    NILFS [nilfs_segbuf_wait]:676 segbuf->sb_segnum 6784
    NILFS [nilfs_segbuf_wait]:676 segbuf->sb_segnum 6785

    NILFS [nilfs_segctor_complete_write]:2100 bh->b_count 0, bh->b_blocknr 13895680, bh->b_size 13897727, bh->b_page 0000000000001a82

    BUG: unable to handle kernel paging request at 0000000000001a82
    IP: [] nilfs_end_page_io+0x12/0xd0 [nilfs2]

    Usually, for every segment we collect dirty files in list. Then, dirty
    blocks are gathered for every dirty file, prepared for write and
    submitted by means of nilfs_segbuf_submit_bh() call. Finally, it takes
    place complete write phase after calling nilfs_end_bio_write() on the
    block layer. Buffers/pages are marked as not dirty on final phase and
    processed files removed from the list of dirty files.

    It is possible to see that we had three prepare_write and submit_bio
    phases before segbuf_wait and complete_write phase. Moreover, segments
    compete between each other for dirty blocks because on every iteration
    of segments processing dirty buffer_heads are added in several lists of
    payload_buffers:

    [SEGMENT 6784]: bh->b_assoc_buffers.next ffff880218a0d5f8, bh->b_assoc_buffers.prev ffff880218bcdf50
    [SEGMENT 6785]: bh->b_assoc_buffers.next ffff880218a0d5f8, bh->b_assoc_buffers.prev ffff880222cc7ee8

    The next pointer is the same but prev pointer has changed. It means
    that buffer_head has next pointer from one list but prev pointer from
    another. Such modification can be made several times. And, finally, it
    can be resulted in various issues: (1) segctor hanging, (2) segctor
    crashing, (3) file system metadata corruption.

    FIX:
    This patch adds:

    (1) setting of BH_Async_Write flag in nilfs_segctor_prepare_write()
    for every proccessed dirty block;

    (2) checking of BH_Async_Write flag in
    nilfs_lookup_dirty_data_buffers() and
    nilfs_lookup_dirty_node_buffers();

    (3) clearing of BH_Async_Write flag in nilfs_segctor_complete_write(),
    nilfs_abort_logs(), nilfs_forget_buffer(), nilfs_clear_dirty_page().

    Reported-by: Jerome Poulin
    Reported-by: Anton Eliasson
    Cc: Paul Fertser
    Cc: ARAI Shun-ichi
    Cc: Piotr Szymaniak
    Cc: Juan Barry Manuel Canham
    Cc: Zahid Chowdhury
    Cc: Elmer Zhang
    Cc: Kenneth Langga
    Signed-off-by: Vyacheslav Dubeyko
    Acked-by: Ryusuke Konishi
    Cc:
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Vyacheslav Dubeyko
     

01 May, 2013

2 commits

  • Change test_bit(PG_locked, &page->flags) to PageLocked().

    Signed-off-by: Vyacheslav Dubeyko
    Cc: Ryusuke Konishi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Vyacheslav Dubeyko
     
  • …river's internal error or metadata corruption

    The NILFS2 driver remounts itself in RO mode in the case of discovering
    metadata corruption (for example, discovering a broken bmap). But
    usually, this takes place when there have been file system operations
    before remounting in RO mode.

    Thereby, NILFS2 driver can be in RO mode with presence of dirty pages in
    modified inodes' address spaces. It results in flush kernel thread's
    infinite trying to flush dirty pages in RO mode. As a result, it is
    possible to see such side effects as: (1) flush kernel thread occupies
    50% - 99% of CPU time; (2) system can't be shutdowned without manual
    power switch off.

    SYMPTOMS:
    (1) System log contains error message: "Remounting filesystem read-only".
    (2) The flush kernel thread occupies 50% - 99% of CPU time.
    (3) The system can't be shutdowned without manual power switch off.

    REPRODUCTION PATH:
    (1) Create volume group with name "unencrypted" by means of vgcreate utility.
    (2) Run script (prepared by Anthony Doggett <Anthony2486@interfaces.org.uk>):

    ----------------[BEGIN SCRIPT]--------------------
    #!/bin/bash

    VG=unencrypted
    #apt-get install nilfs-tools darcs
    lvcreate --size 2G --name ntest $VG
    mkfs.nilfs2 -b 1024 -B 8192 /dev/mapper/$VG-ntest
    mkdir /var/tmp/n
    mkdir /var/tmp/n/ntest
    mount /dev/mapper/$VG-ntest /var/tmp/n/ntest
    mkdir /var/tmp/n/ntest/thedir
    cd /var/tmp/n/ntest/thedir
    sleep 2
    date
    darcs init
    sleep 2
    dmesg|tail -n 5
    date
    darcs whatsnew || true
    date
    sleep 2
    dmesg|tail -n 5
    ----------------[END SCRIPT]--------------------

    (3) Try to shutdown the system.

    REPRODUCIBILITY: 100%

    FIX:

    This patch implements checking mount state of NILFS2 driver in
    nilfs_writepage(), nilfs_writepages() and nilfs_mdt_write_page()
    methods. If it is detected the RO mount state then all dirty pages are
    simply discarded with warning messages is written in system log.

    [akpm@linux-foundation.org: fix printk warning]
    Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
    Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
    Cc: Anthony Doggett <Anthony2486@interfaces.org.uk>
    Cc: ARAI Shun-ichi <hermes@ceres.dti.ne.jp>
    Cc: Piotr Szymaniak <szarpaj@grubelek.pl>
    Cc: Zahid Chowdhury <zahid.chowdhury@starsolutions.com>
    Cc: Elmer Zhang <freeboy6716@gmail.com>
    Cc: Wu Fengguang <fengguang.wu@intel.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

    Vyacheslav Dubeyko
     

12 Dec, 2012

1 commit

  • Overhaul struct address_space.assoc_mapping renaming it to
    address_space.private_data and its type is redefined to void*. By this
    approach we consistently name the .private_* elements from struct
    address_space as well as allow extended usage for address_space
    association with other data structures through ->private_data.

    Also, all users of old ->assoc_mapping element are converted to reflect
    its new name and type change (->private_data).

    Signed-off-by: Rafael Aquini
    Cc: Rusty Russell
    Cc: "Michael S. Tsirkin"
    Cc: Rik van Riel
    Cc: Mel Gorman
    Cc: Andi Kleen
    Cc: Konrad Rzeszutek Wilk
    Cc: Minchan Kim
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Rafael Aquini
     

20 Mar, 2012

1 commit


10 May, 2011

3 commits

  • This replaces nilfs_mdt_mark_buffer_dirty and nilfs_btnode_mark_dirty
    macros with mark_buffer_dirty and gets rid of nilfs_mark_buffer_dirty,
    an own mark buffer dirty function.

    Signed-off-by: Ryusuke Konishi

    Ryusuke Konishi
     
  • In the current nilfs, page cache for btree nodes and meta data files
    do not set a valid back pointer to the host inode in mapping->host.

    This will change it so that every address space in nilfs uses
    mapping->host to hold its host inode.

    Signed-off-by: Ryusuke Konishi

    Ryusuke Konishi
     
  • Previously, nilfs was cloning pages for mmapped region to freeze their
    data and ensure consistency of checksum during writeback cycles. A
    private page allocator was used for this page cloning. But, we no
    longer need to do that since clear_page_dirty_for_io function sets up
    pte so that vm_ops->page_mkwrite function is called right before the
    mmapped pages are modified and nilfs_page_mkwrite function can safely
    wait for the pages to be written back to disk.

    So, this stops making a copy of mmapped pages during writeback, and
    eliminates the private page allocation and deallocation functions from
    nilfs.

    Signed-off-by: Ryusuke Konishi

    Ryusuke Konishi
     

06 Apr, 2011

1 commit

  • With the ->sync_page() hook gone, we have a few users that
    add their own static address_space_operations without any
    functions defined.

    fs/inode.c already has an empty_aops that it uses for init
    purposes. Lets export that and use it in the places where
    an otherwise empty aops was defined.

    Signed-off-by: Jens Axboe

    Jens Axboe
     

30 Mar, 2011

1 commit

  • Nilfs in 2.6.39-rc1 hit the following oops:

    BUG: unable to handle kernel NULL pointer dereference at 0000000000000048
    IP: [] try_to_release_page+0x2a/0x3d
    PGD 234cb6067 PUD 234c72067 PMD 0
    Oops: 0000 [#1] SMP

    Process truncate (pid: 10995, threadinfo ffff8802353c2000, task ffff880234cfa000)
    Stack:
    ffff8802333c77b8 ffffffff810b64b0 0000000000003802 ffffffffa0052cca
    0000000000000000 ffff8802353c3b58 0000000000000000 ffff8802353c3b58
    0000000000000001 0000000000000000 ffffea0007b92308 ffffea0007b92308
    Call Trace:
    [] ? invalidate_inode_pages2_range+0x15f/0x273
    [] ? nilfs_palloc_get_block+0x2d/0xaf [nilfs2]
    [] ? bit_waitqueue+0x14/0xa1
    [] ? wake_up_bit+0x10/0x20
    [] ? nilfs_forget_buffer+0x66/0x7a [nilfs2]
    [] ? nilfs_btree_concat_left+0x5c/0x77 [nilfs2]
    [] ? nilfs_btree_delete+0x395/0x3cf [nilfs2]
    [] ? nilfs_bmap_do_delete+0x6e/0x79 [nilfs2]
    [] ? nilfs_btree_last_key+0x14b/0x15e [nilfs2]
    [] ? nilfs_bmap_truncate+0x2f/0x83 [nilfs2]
    [] ? nilfs_bmap_last_key+0x35/0x62 [nilfs2]
    [] ? nilfs_truncate_bmap+0x6b/0xc7 [nilfs2]
    [] ? nilfs_truncate+0x79/0xe4 [nilfs2]
    [] ? vmtruncate+0x33/0x3b
    [] ? nilfs_setattr+0x4d/0x8c [nilfs2]
    [] ? do_page_fault+0x31b/0x356
    [] ? notify_change+0x17d/0x262
    [] ? do_truncate+0x65/0x80
    [] ? sys_ftruncate+0xf1/0xf6
    [] ? system_call_fastpath+0x16/0x1b
    Code: c3 48 83 ec 08 48 8b 17 48 8b 47 18 80 e2 01 75 04 0f 0b eb fe 48 8b 17 80 e6 20 74 05 31 c0 41 59 c3 48 85 c0 74 11 48 8b 40 58
    8b 40 48 48 85 c0 74 04 41 58 ff e0 59 e9 b1 b5 05 00 41 54
    RIP [] try_to_release_page+0x2a/0x3d
    RSP
    CR2: 0000000000000048

    This oops was brought in by the change "block: remove per-queue
    plugging" (commit: 7eaceaccab5f40bb). It initializes mapping->a_ops
    with a NULL pointer for some pages in nilfs (e.g. btree node pages),
    but mm code doesn't NULL pointer checks against mapping->a_ops. (the
    check is done for each callback function)

    This corrects the aops initialization and fixes the oops.

    Signed-off-by: Ryusuke Konishi
    Acked-by: Jens Axboe

    Ryusuke Konishi
     

10 Mar, 2011

2 commits


24 Feb, 2011

1 commit

  • Michael Leun reported that running parallel opens on a fuse filesystem
    can trigger a "kernel BUG at mm/truncate.c:475"

    Gurudas Pai reported the same bug on NFS.

    The reason is, unmap_mapping_range() is not prepared for more than
    one concurrent invocation per inode. For example:

    thread1: going through a big range, stops in the middle of a vma and
    stores the restart address in vm_truncate_count.

    thread2: comes in with a small (e.g. single page) unmap request on
    the same vma, somewhere before restart_address, finds that the
    vma was already unmapped up to the restart address and happily
    returns without doing anything.

    Another scenario would be two big unmap requests, both having to
    restart the unmapping and each one setting vm_truncate_count to its
    own value. This could go on forever without any of them being able to
    finish.

    Truncate and hole punching already serialize with i_mutex. Other
    callers of unmap_mapping_range() do not, and it's difficult to get
    i_mutex protection for all callers. In particular ->d_revalidate(),
    which calls invalidate_inode_pages2_range() in fuse, may be called
    with or without i_mutex.

    This patch adds a new mutex to 'struct address_space' to prevent
    running multiple concurrent unmap_mapping_range() on the same mapping.

    [ We'll hopefully get rid of all this with the upcoming mm
    preemptibility series by Peter Zijlstra, the "mm: Remove i_mmap_mutex
    lockbreak" patch in particular. But that is for 2.6.39 ]

    Signed-off-by: Miklos Szeredi
    Reported-by: Michael Leun
    Reported-by: Gurudas Pai
    Tested-by: Gurudas Pai
    Acked-by: Hugh Dickins
    Cc: stable@kernel.org
    Signed-off-by: Linus Torvalds

    Miklos Szeredi
     

10 Jan, 2011

2 commits

  • Will correct the following checkpatch error:

    ERROR: trailing whitespace
    #494: FILE: page.c:494:
    + $

    Signed-off-by: Ryusuke Konishi

    Ryusuke Konishi
     
  • This adds fiemap to nilfs. Two new functions, nilfs_fiemap and
    nilfs_find_uncommitted_extent are added.

    nilfs_fiemap() implements the fiemap inode operation, and
    nilfs_find_uncommitted_extent() helps to get a range of data blocks
    whose physical location has not been determined.

    nilfs_fiemap() collects extent information by looping through
    nilfs_bmap_lookup_contig and nilfs_find_uncommitted_extent routines.

    Signed-off-by: Ryusuke Konishi

    Ryusuke Konishi
     

23 Oct, 2010

3 commits

  • This applies prepared rollback function and redirect function of
    metadata file to DAT file, and eliminates GCDAT inode.

    Signed-off-by: Ryusuke Konishi

    Ryusuke Konishi
     
  • During garbage collection (GC), DAT file, which converts virtual block
    number to real block number, may return disk block number that is not
    yet written to the device.

    To avoid access to unwritten blocks, the current implementation stores
    changes to the caches of GCDAT during GC and atomically commit the
    changes into the DAT file after they are written to the device.

    This patch, instead, adds a function that makes a copy of specified
    buffer and stores it in nilfs_shadow_map, and a function to get the
    backup copy as needed (nilfs_mdt_freeze_buffer and
    nilfs_mdt_get_frozen_buffer respectively).

    Before DAT changes block number in an entry block, it makes a copy and
    redirect access to the buffer so that address conversion function
    (i.e. nilfs_dat_translate) refers to the old address saved in the
    copy.

    This patch gives requisites for such redirection.

    Signed-off-by: Ryusuke Konishi

    Ryusuke Konishi
     
  • This adds optional function to metadata files which makes a copy of
    bmap, page caches, and b-tree node cache, and rolls back to the copy
    as needed.

    This enhancement is intended to displace gcdat inode that provides a
    similar function in a different way.

    In this patch, nilfs_shadow_map structure is added to store a copy of
    the foregoing states. nilfs_mdt_setup_shadow_map relates this
    structure to a metadata file. And, nilfs_mdt_save_to_shadow_map() and
    nilfs_mdt_restore_from_shadow_map() provides save and restore
    functions respectively. Finally, nilfs_mdt_clear_shadow_map() clears
    states of nilfs_shadow_map.

    The copy of b-tree node cache and page cache is made by duplicating
    only dirty pages into corresponding caches in nilfs_shadow_map. Their
    restoration is done by clearing dirty pages from original caches and
    by copying dirty pages back from nilfs_shadow_map.

    Signed-off-by: Ryusuke Konishi

    Ryusuke Konishi
     

23 Jul, 2010

1 commit


30 Mar, 2010

1 commit

  • …it slab.h inclusion from percpu.h

    percpu.h is included by sched.h and module.h and thus ends up being
    included when building most .c files. percpu.h includes slab.h which
    in turn includes gfp.h making everything defined by the two files
    universally available and complicating inclusion dependencies.

    percpu.h -> slab.h dependency is about to be removed. Prepare for
    this change by updating users of gfp and slab facilities include those
    headers directly instead of assuming availability. As this conversion
    needs to touch large number of source files, the following script is
    used as the basis of conversion.

    http://userweb.kernel.org/~tj/misc/slabh-sweep.py

    The script does the followings.

    * Scan files for gfp and slab usages and update includes such that
    only the necessary includes are there. ie. if only gfp is used,
    gfp.h, if slab is used, slab.h.

    * When the script inserts a new include, it looks at the include
    blocks and try to put the new include such that its order conforms
    to its surrounding. It's put in the include block which contains
    core kernel includes, in the same order that the rest are ordered -
    alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
    doesn't seem to be any matching order.

    * If the script can't find a place to put a new include (mostly
    because the file doesn't have fitting include block), it prints out
    an error message indicating which .h file needs to be added to the
    file.

    The conversion was done in the following steps.

    1. The initial automatic conversion of all .c files updated slightly
    over 4000 files, deleting around 700 includes and adding ~480 gfp.h
    and ~3000 slab.h inclusions. The script emitted errors for ~400
    files.

    2. Each error was manually checked. Some didn't need the inclusion,
    some needed manual addition while adding it to implementation .h or
    embedding .c file was more appropriate for others. This step added
    inclusions to around 150 files.

    3. The script was run again and the output was compared to the edits
    from #2 to make sure no file was left behind.

    4. Several build tests were done and a couple of problems were fixed.
    e.g. lib/decompress_*.c used malloc/free() wrappers around slab
    APIs requiring slab.h to be added manually.

    5. The script was run on all .h files but without automatically
    editing them as sprinkling gfp.h and slab.h inclusions around .h
    files could easily lead to inclusion dependency hell. Most gfp.h
    inclusion directives were ignored as stuff from gfp.h was usually
    wildly available and often used in preprocessor macros. Each
    slab.h inclusion directive was examined and added manually as
    necessary.

    6. percpu.h was updated not to include slab.h.

    7. Build test were done on the following configurations and failures
    were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
    distributed build env didn't work with gcov compiles) and a few
    more options had to be turned off depending on archs to make things
    build (like ipr on powerpc/64 which failed due to missing writeq).

    * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
    * powerpc and powerpc64 SMP allmodconfig
    * sparc and sparc64 SMP allmodconfig
    * ia64 SMP allmodconfig
    * s390 SMP allmodconfig
    * alpha SMP allmodconfig
    * um on x86_64 SMP allmodconfig

    8. percpu.h modifications were reverted so that it could be applied as
    a separate patch and serve as bisection point.

    Given the fact that I had only a couple of failures from tests on step
    6, I'm fairly confident about the coverage of this conversion patch.
    If there is a breakage, it's likely to be something in one of the arch
    headers which should be easily discoverable easily on most builds of
    the specific arch.

    Signed-off-by: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

14 Mar, 2010

1 commit


10 May, 2009

1 commit

  • This would fix the following failure during GC:

    nilfs_cpfile_delete_checkpoints: cannot delete block
    NILFS: GC failed during preparation: cannot delete checkpoints: err=-2

    The problem was caused by a break in state consistency between page
    cache and btree; the above block was removed from the btree but the
    page buffering the block was remaining in the page cache in dirty
    state.

    This resolves the inconsistency by ensuring to clear dirty state of
    the page buffering the deleted block.

    Reported-by: David Arendt
    Signed-off-by: Ryusuke Konishi

    Ryusuke Konishi
     

07 Apr, 2009

2 commits

  • Pekka Enberg advised me:
    > It would be nice if BUG(), BUG_ON(), and panic() calls would be
    > converted to proper error handling using WARN_ON() calls. The BUG()
    > call in nilfs_cpfile_delete_checkpoints(), for example, looks to be
    > triggerable from user-space via the ioctl() system call.

    This will follow the comment and keep them to a minimum.

    Acked-by: Pekka Enberg
    Signed-off-by: Ryusuke Konishi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ryusuke Konishi
     
  • This adds common routines for buffer/page operations used in B-tree
    node caches, meta data files, or segment constructor (log writer).

    NILFS uses copy functions for buffers and pages due to the following
    reasons:

    1) Relocation required for COW
    Since NILFS changes address of on-disk blocks, moving buffers
    in page cache is needed for the buffers which are not addressed
    by a file offset. If buffer size is smaller than page size,
    this involves partial copy of pages.

    2) Freezing mmapped pages
    NILFS calculates checksums for each log to ensure its validity.
    If page data changes after the checksum calculation, this validity
    check will not work correctly. To avoid this failure for mmaped
    pages, NILFS freezes their data by copying.

    3) Copy-on-write for DAT pages
    NILFS makes clones of DAT page caches in a copy-on-write manner
    during GC processes, and this ensures atomicity and consistency
    of the DAT in the transient state.

    In addition, NILFS uses two obsolete functions, nilfs_mark_buffer_dirty()
    and nilfs_clear_page_dirty() respectively.

    * nilfs_mark_buffer_dirty() was required to avoid NULL pointer
    dereference faults:

    Since the page cache of B-tree node pages or data page cache of pseudo
    inodes does not have a valid mapping->host, calling mark_buffer_dirty()
    for their buffers causes the fault; it calls __mark_inode_dirty(NULL)
    through __set_page_dirty().

    * nilfs_clear_page_dirty() was needed in the two cases:

    1) For B-tree node pages and data pages of the dat/gcdat, NILFS2 clears
    page dirty flags when it copies back pages from the cloned cache
    (gcdat->{i_mapping,i_btnode_cache}) to its original cache
    (dat->{i_mapping,i_btnode_cache}).

    2) Some B-tree operations like insertion or deletion may dispose buffers
    in dirty state, and this needs to cancel the dirty state of their
    pages. clear_page_dirty_for_io() caused faults because it does not
    clear the dirty tag on the page cache.

    Signed-off-by: Seiji Kihara
    Signed-off-by: Ryusuke Konishi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ryusuke Konishi