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  • Zdenek Kabelac's avatar
    md: free unused memory after bitmap resize · b7d3f2b5
    Zdenek Kabelac authored
    
    [ Upstream commit 0868b99c
    
     ]
    
    When bitmap is resized, the old kalloced chunks just are not released
    once the resized bitmap starts to use new space.
    
    This fixes in particular kmemleak reports like this one:
    
    unreferenced object 0xffff8f4311e9c000 (size 4096):
      comm "lvm", pid 19333, jiffies 4295263268 (age 528.265s)
      hex dump (first 32 bytes):
        02 80 02 80 02 80 02 80 02 80 02 80 02 80 02 80  ................
        02 80 02 80 02 80 02 80 02 80 02 80 02 80 02 80  ................
      backtrace:
        [<ffffffffa69471ca>] kmemleak_alloc+0x4a/0xa0
        [<ffffffffa628c10e>] kmem_cache_alloc_trace+0x14e/0x2e0
        [<ffffffffa676cfec>] bitmap_checkpage+0x7c/0x110
        [<ffffffffa676d0c5>] bitmap_get_counter+0x45/0xd0
        [<ffffffffa676d6b3>] bitmap_set_memory_bits+0x43/0xe0
        [<ffffffffa676e41c>] bitmap_init_from_disk+0x23c/0x530
        [<ffffffffa676f1ae>] bitmap_load+0xbe/0x160
        [<ffffffffc04c47d3>] raid_preresume+0x203/0x2f0 [dm_raid]
        [<ffffffffa677762f>] dm_table_resume_targets+0x4f/0xe0
        [<ffffffffa6774b52>] dm_resume+0x122/0x140
        [<ffffffffa6779b9f>] dev_suspend+0x18f/0x290
        [<ffffffffa677a3a7>] ctl_ioctl+0x287/0x560
        [<ffffffffa677a693>] dm_ctl_ioctl+0x13/0x20
        [<ffffffffa62d6b46>] do_vfs_ioctl+0xa6/0x750
        [<ffffffffa62d7269>] SyS_ioctl+0x79/0x90
        [<ffffffffa6956d41>] entry_SYSCALL_64_fastpath+0x1f/0xc2
    
    Signed-off-by: default avatarZdenek Kabelac <zkabelac@redhat.com>
    Signed-off-by: default avatarShaohua Li <shli@fb.com>
    Signed-off-by: default avatarSasha Levin <alexander.levin@verizon.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    b7d3f2b5