lkml.org 
[lkml]   [2011]   [Mar]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    SubjectRe: [dm-devel] [PATCH] Fix over-zealous flush_disk when changing device size.
    Date
    NeilBrown <neilb@suse.de> writes:

    >> Synchronous notification of errors. If we don't try to write everything
    >> back immediately after the size change, we don't see dirty pages in
    >> zapped regions until the writeout/page cache management takes it into
    >> its head to try to clean the pages.
    >>
    >
    > So if you just want synchronous errors, I think you want:
    > fsync_bdev()
    >
    > which calls sync_filesystem() if it can find a filesystem, else
    > sync_blockdev(); (sync_filesystem itself calls sync_blockdev too).

    ... which deadlocks md. ;-) writeback_inodes_sb_nr is waiting for the
    flusher thread to write back the dirty data. The flusher thread is
    stuck in md_write_start, here:

    wait_event(mddev->sb_wait,
    !test_bit(MD_CHANGE_PENDING, &mddev->flags));

    This is after reverting your change, and replacing the flush_disk call
    in check_disk_size_change with a call to fsync_bdev. I'm not familiar
    enough with md to really suggest a way forward. Neil?

    Cheers,
    Jeff

    md127: detected capacity change from 267386880 to 401080320
    INFO: task md127_raid5:2255 blocked for more than 120 seconds.
    "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
    message.
    md127_raid5 D ffff88011d010690 5416 2255 2 0x00000080
    ffff88010fcc7990 0000000000000046 ffff880100000000 ffffffff812070c9
    0000000000014d00 ffff88011d010100 ffff88011d010690 ffff88010fcc7fd8
    ffff88011d010698 0000000000014d00 ffff88010fcc6010 0000000000014d00
    Call Trace:
    [<ffffffff812070c9>] ? cpumask_next_and+0x29/0x50
    [<ffffffff81493df5>] schedule_timeout+0x265/0x2d0
    [<ffffffff8104b341>] ? enqueue_task+0x61/0x80
    [<ffffffff81493a25>] wait_for_common+0x115/0x180
    [<ffffffff81057850>] ? default_wake_function+0x0/0x10
    [<ffffffff81493b38>] wait_for_completion+0x18/0x20
    [<ffffffff8115cce2>] writeback_inodes_sb_nr+0x72/0xa0
    [<ffffffff8115cfad>] writeback_inodes_sb+0x4d/0x60
    [<ffffffff81162499>] __sync_filesystem+0x49/0x90
    [<ffffffff81162592>] sync_filesystem+0x32/0x60
    [<ffffffff8116bc59>] fsync_bdev+0x29/0x70
    [<ffffffff8116bcea>] check_disk_size_change+0x4a/0xb0
    [<ffffffff81208e27>] ? kobject_put+0x27/0x60
    [<ffffffff8116bdaf>] revalidate_disk+0x5f/0x90
    [<ffffffffa031155a>] raid5_finish_reshape+0x9a/0x1e0 [raid456]
    [<ffffffff8138a933>] reap_sync_thread+0x63/0x130
    [<ffffffff8138c8a6>] md_check_recovery+0x1f6/0x6f0
    [<ffffffffa03150ab>] raid5d+0x3b/0x610 [raid456]
    [<ffffffff810804c9>] ? prepare_to_wait+0x59/0x90
    [<ffffffff81387ee9>] md_thread+0x119/0x150
    [<ffffffff810801d0>] ? autoremove_wake_function+0x0/0x40
    [<ffffffff81387dd0>] ? md_thread+0x0/0x150
    [<ffffffff8107fb56>] kthread+0x96/0xa0
    [<ffffffff8100cc04>] kernel_thread_helper+0x4/0x10
    [<ffffffff8107fac0>] ? kthread+0x0/0xa0
    [<ffffffff8100cc00>] ? kernel_thread_helper+0x0/0x10
    INFO: task flush-9:127:2288 blocked for more than 120 seconds.
    "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
    message.
    flush-9:127 D ffff88011cee30a0 4664 2288 2 0x00000080
    ffff88011b0af6a0 0000000000000046 0000000000000000 0000000000000000
    0000000000014d00 ffff88011cee2b10 ffff88011cee30a0 ffff88011b0affd8
    ffff88011cee30a8 0000000000014d00 ffff88011b0ae010 0000000000014d00
    Call Trace:
    [<ffffffff8138bbb5>] md_write_start+0xa5/0x1c0
    [<ffffffff810801d0>] ? autoremove_wake_function+0x0/0x40
    [<ffffffffa0316435>] make_request+0x45/0x6c0 [raid456]
    [<ffffffff811fbfcb>] ? blkiocg_update_dispatch_stats+0x8b/0xd0
    [<ffffffff81385ca3>] md_make_request+0xd3/0x210
    [<ffffffff811ee9da>] generic_make_request+0x2ea/0x5d0
    [<ffffffff810e9cde>] ? mempool_alloc+0x5e/0x140
    [<ffffffff811eed41>] submit_bio+0x81/0x110
    [<ffffffff811699c6>] ? bio_alloc_bioset+0x56/0xf0
    [<ffffffff81163ef6>] submit_bh+0xe6/0x140
    [<ffffffff81165ad0>] __block_write_full_page+0x200/0x390
    [<ffffffff811655a0>] ? end_buffer_async_write+0x0/0x1a0
    [<ffffffff8116667e>] block_write_full_page_endio+0xde/0x110
    [<ffffffffa037d3b0>] ? buffer_unmapped+0x0/0x20 [ext3]
    [<ffffffff811666c0>] block_write_full_page+0x10/0x20
    [<ffffffffa037de6d>] ext3_writeback_writepage+0x11d/0x170 [ext3]
    [<ffffffff810f0152>] __writepage+0x12/0x40
    [<ffffffff810f12b4>] write_cache_pages+0x1a4/0x490
    [<ffffffff810f0140>] ? __writepage+0x0/0x40
    [<ffffffff810f15bf>] generic_writepages+0x1f/0x30
    [<ffffffff810f15f5>] do_writepages+0x25/0x30
    [<ffffffff8115d5f0>] writeback_single_inode+0x90/0x220
    [<ffffffff8115d9b6>] writeback_sb_inodes+0xc6/0x170
    [<ffffffff8115dd3f>] wb_writeback+0x17f/0x430
    [<ffffffff8106e217>] ? lock_timer_base+0x37/0x70
    [<ffffffff8115e08d>] wb_do_writeback+0x9d/0x270
    [<ffffffff8106e330>] ? process_timeout+0x0/0x10
    [<ffffffff8115e302>] bdi_writeback_thread+0xa2/0x280
    [<ffffffff8115e260>] ? bdi_writeback_thread+0x0/0x280
    [<ffffffff8115e260>] ? bdi_writeback_thread+0x0/0x280
    [<ffffffff8107fb56>] kthread+0x96/0xa0
    [<ffffffff8100cc04>] kernel_thread_helper+0x4/0x10
    [<ffffffff8107fac0>] ? kthread+0x0/0xa0
    [<ffffffff8100cc00>] ? kernel_thread_helper+0x0/0x10
    INFO: task updatedb:2342 blocked for more than 120 seconds.
    "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
    message.
    updatedb D ffff88011bd77af0 5136 2342 2323 0x00000080
    ffff88011c877cb8 0000000000000086 0000000000000000 ffff88011c1829a8
    0000000000014d00 ffff88011bd77560 ffff88011bd77af0 ffff88011c877fd8
    ffff88011bd77af8 0000000000014d00 ffff88011c876010 0000000000014d00
    Call Trace:
    [<ffffffff81165130>] ? sync_buffer+0x0/0x50
    [<ffffffff8149382b>] io_schedule+0x6b/0xb0
    [<ffffffff8116516b>] sync_buffer+0x3b/0x50
    [<ffffffff81494057>] __wait_on_bit+0x57/0x80
    [<ffffffff811699c6>] ? bio_alloc_bioset+0x56/0xf0
    [<ffffffff81165130>] ? sync_buffer+0x0/0x50
    [<ffffffff814940f3>] out_of_line_wait_on_bit+0x73/0x90
    [<ffffffff81080210>] ? wake_bit_function+0x0/0x40
    [<ffffffff81165126>] __wait_on_buffer+0x26/0x30
    [<ffffffffa038006c>] ext3_bread+0x5c/0x80 [ext3]
    [<ffffffffa037ba63>] ext3_readdir+0x1f3/0x600 [ext3]
    [<ffffffff8114a650>] ? filldir+0x0/0xe0
    [<ffffffff8114a650>] ? filldir+0x0/0xe0
    [<ffffffff8114a7e0>] vfs_readdir+0xb0/0xd0
    [<ffffffff8114a964>] sys_getdents+0x84/0xf0
    [<ffffffff8100bdd2>] system_call_fastpath+0x16/0x1b


    diff --git a/block/genhd.c b/block/genhd.c
    index cbf1112..6a5b772 100644
    --- a/block/genhd.c
    +++ b/block/genhd.c
    @@ -1355,7 +1355,7 @@ int invalidate_partition(struct gendisk *disk, int partno)
    struct block_device *bdev = bdget_disk(disk, partno);
    if (bdev) {
    fsync_bdev(bdev);
    - res = __invalidate_device(bdev, true);
    + res = __invalidate_device(bdev);
    bdput(bdev);
    }
    return res;
    diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
    index 77fc76f..b9ba04f 100644
    --- a/drivers/block/floppy.c
    +++ b/drivers/block/floppy.c
    @@ -3281,7 +3281,7 @@ static int set_geometry(unsigned int cmd, struct floppy_struct *g,
    struct block_device *bdev = opened_bdev[cnt];
    if (!bdev || ITYPE(drive_state[cnt].fd_device) != type)
    continue;
    - __invalidate_device(bdev, true);
    + __invalidate_device(bdev);
    }
    mutex_unlock(&open_lock);
    } else {
    diff --git a/fs/block_dev.c b/fs/block_dev.c
    index 8892870..5aae241 100644
    --- a/fs/block_dev.c
    +++ b/fs/block_dev.c
    @@ -934,9 +934,9 @@ EXPORT_SYMBOL_GPL(bd_unlink_disk_holder);
    * when a disk has been changed -- either by a media change or online
    * resize.
    */
    -static void flush_disk(struct block_device *bdev, bool kill_dirty)
    +static void flush_disk(struct block_device *bdev)
    {
    - if (__invalidate_device(bdev, kill_dirty)) {
    + if (__invalidate_device(bdev)) {
    char name[BDEVNAME_SIZE] = "";

    if (bdev->bd_disk)
    @@ -973,7 +973,7 @@ void check_disk_size_change(struct gendisk *disk, struct block_device *bdev)
    "%s: detected capacity change from %lld to %lld\n",
    name, bdev_size, disk_size);
    i_size_write(bdev->bd_inode, disk_size);
    - flush_disk(bdev, false);
    + fsync_bdev(bdev);
    }
    }
    EXPORT_SYMBOL(check_disk_size_change);
    @@ -1026,7 +1026,7 @@ int check_disk_change(struct block_device *bdev)
    if (!(events & DISK_EVENT_MEDIA_CHANGE))
    return 0;

    - flush_disk(bdev, true);
    + flush_disk(bdev);
    if (bdops->revalidate_disk)
    bdops->revalidate_disk(bdev->bd_disk);
    return 1;
    @@ -1607,7 +1607,7 @@ fail:
    }
    EXPORT_SYMBOL(lookup_bdev);

    -int __invalidate_device(struct block_device *bdev, bool kill_dirty)
    +int __invalidate_device(struct block_device *bdev)
    {
    struct super_block *sb = get_super(bdev);
    int res = 0;
    @@ -1620,7 +1620,7 @@ int __invalidate_device(struct block_device *bdev, bool kill_dirty)
    * hold).
    */
    shrink_dcache_sb(sb);
    - res = invalidate_inodes(sb, kill_dirty);
    + res = invalidate_inodes(sb);
    drop_super(sb);
    }
    invalidate_bdev(bdev);
    diff --git a/fs/inode.c b/fs/inode.c
    index 0647d80..9c2b795 100644
    --- a/fs/inode.c
    +++ b/fs/inode.c
    @@ -548,14 +548,11 @@ void evict_inodes(struct super_block *sb)
    /**
    * invalidate_inodes - attempt to free all inodes on a superblock
    * @sb: superblock to operate on
    - * @kill_dirty: flag to guide handling of dirty inodes
    *
    * Attempts to free all inodes for a given superblock. If there were any
    * busy inodes return a non-zero value, else zero.
    - * If @kill_dirty is set, discard dirty inodes too, otherwise treat
    - * them as busy.
    */
    -int invalidate_inodes(struct super_block *sb, bool kill_dirty)
    +int invalidate_inodes(struct super_block *sb)
    {
    int busy = 0;
    struct inode *inode, *next;
    @@ -567,10 +564,6 @@ int invalidate_inodes(struct super_block *sb, bool kill_dirty)
    list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) {
    if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE))
    continue;
    - if (inode->i_state & I_DIRTY && !kill_dirty) {
    - busy = 1;
    - continue;
    - }
    if (atomic_read(&inode->i_count)) {
    busy = 1;
    continue;
    diff --git a/fs/internal.h b/fs/internal.h
    index f3d15de..bee95ea 100644
    --- a/fs/internal.h
    +++ b/fs/internal.h
    @@ -125,4 +125,4 @@ extern long do_handle_open(int mountdirfd,
    */
    extern int get_nr_dirty_inodes(void);
    extern void evict_inodes(struct super_block *);
    -extern int invalidate_inodes(struct super_block *, bool);
    +extern int invalidate_inodes(struct super_block *);
    diff --git a/include/linux/fs.h b/include/linux/fs.h
    index 13df14e..ff9a159 100644
    --- a/include/linux/fs.h
    +++ b/include/linux/fs.h
    @@ -2155,7 +2155,7 @@ extern void check_disk_size_change(struct gendisk *disk,
    struct block_device *bdev);
    extern int revalidate_disk(struct gendisk *);
    extern int check_disk_change(struct block_device *);
    -extern int __invalidate_device(struct block_device *, bool);
    +extern int __invalidate_device(struct block_device *);
    extern int invalidate_partition(struct gendisk *, int);
    #endif
    unsigned long invalidate_mapping_pages(struct address_space *mapping,

    \
     
     \ /
      Last update: 2011-03-16 21:33    [W:0.040 / U:57.896 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site