1. 01 Oct, 2008 3 commits
    • Chandra Seetharaman's avatar
      dm mpath: add missing path switching locking · 7253a334
      Chandra Seetharaman authored
      Moving the path activation to workqueue along with scsi_dh patches introduced
      a race. It is due to the fact that the current_pgpath (in the multipath data
      structure) can be modified if changes happen in any of the paths leading to
      the lun. If the changes lead to current_pgpath being set to NULL, then it
      leads to the invalid access which results in the panic below.
      
      This patch fixes that by storing the pgpath to activate in the multipath data
      structure and properly protecting it.
      
      Note that if activate_path is called twice in succession with different pgpath,
      with the second one being called before the first one is done, then activate
      path will be called twice for the second pgpath, which is fine.
      
      Unable to handle kernel paging request for data at address 0x00000020
      Faulting instruction address: 0xd000000000aa1844
      cpu 0x1: Vector: 300 (Data Access) at [c00000006b987a80]
          pc: d000000000aa1844: .activate_path+0x30/0x218 [dm_multipath]
          lr: c000000000087a2c: .run_workqueue+0x114/0x204
          sp: c00000006b987d00
         msr: 8000000000009032
         dar: 20
       dsisr: 40000000
        current = 0xc0000000676bb3f0
        paca    = 0xc0000000006f3680
          pid   = 2528, comm = kmpath_handlerd
      enter ? for help
      [c00000006b987da0] c000000000087a2c .run_workqueue+0x114/0x204
      [c00000006b987e40] c000000000088b58 .worker_thread+0x120/0x144
      [c00000006b987f00] c00000000008ca70 .kthread+0x78/0xc4
      [c00000006b987f90] c000000000027cc8 .kernel_thread+0x4c/0x68
      Signed-off-by: default avatarChandra Seetharaman <sekharan@us.ibm.com>
      Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
      7253a334
    • Mikulas Patocka's avatar
      dm: cope with access beyond end of device in dm_merge_bvec · b01cd5ac
      Mikulas Patocka authored
      If for any reason dm_merge_bvec() is given an offset beyond the end of the
      device, avoid an oops and always allow one page to be added to an empty bio.
      We'll reject the I/O later after the bio is submitted.
      Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
      Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
      b01cd5ac
    • Mikulas Patocka's avatar
      dm: always allow one page in dm_merge_bvec · 5037108a
      Mikulas Patocka authored
      Some callers assume they can always add at least one page to an empty bio,
      so dm_merge_bvec should not return 0 in this case: we'll reject the I/O
      later after the bio is submitted.
      Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
      Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
      5037108a
  2. 30 Sep, 2008 11 commits
  3. 29 Sep, 2008 23 commits
  4. 28 Sep, 2008 1 commit
  5. 27 Sep, 2008 2 commits