lkml.org 
[lkml]   [2015]   [Apr]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 3.19 056/101] Defer processing of REQ_PREEMPT requests for blocked devices
    Date
    3.19-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Bart Van Assche <bart.vanassche@sandisk.com>

    commit bba0bdd7ad4713d82338bcd9b72d57e9335a664b upstream.

    SCSI transport drivers and SCSI LLDs block a SCSI device if the
    transport layer is not operational. This means that in this state
    no requests should be processed, even if the REQ_PREEMPT flag has
    been set. This patch avoids that a rescan shortly after a cable
    pull sporadically triggers the following kernel oops:

    BUG: unable to handle kernel paging request at ffffc9001a6bc084
    IP: [<ffffffffa04e08f2>] mlx4_ib_post_send+0xd2/0xb30 [mlx4_ib]
    Process rescan-scsi-bus (pid: 9241, threadinfo ffff88053484a000, task ffff880534aae100)
    Call Trace:
    [<ffffffffa0718135>] srp_post_send+0x65/0x70 [ib_srp]
    [<ffffffffa071b9df>] srp_queuecommand+0x1cf/0x3e0 [ib_srp]
    [<ffffffffa0001ff1>] scsi_dispatch_cmd+0x101/0x280 [scsi_mod]
    [<ffffffffa0009ad1>] scsi_request_fn+0x411/0x4d0 [scsi_mod]
    [<ffffffff81223b37>] __blk_run_queue+0x27/0x30
    [<ffffffff8122a8d2>] blk_execute_rq_nowait+0x82/0x110
    [<ffffffff8122a9c2>] blk_execute_rq+0x62/0xf0
    [<ffffffffa000b0e8>] scsi_execute+0xe8/0x190 [scsi_mod]
    [<ffffffffa000b2f3>] scsi_execute_req+0xa3/0x130 [scsi_mod]
    [<ffffffffa000c1aa>] scsi_probe_lun+0x17a/0x450 [scsi_mod]
    [<ffffffffa000ce86>] scsi_probe_and_add_lun+0x156/0x480 [scsi_mod]
    [<ffffffffa000dc2f>] __scsi_scan_target+0xdf/0x1f0 [scsi_mod]
    [<ffffffffa000dfa3>] scsi_scan_host_selected+0x183/0x1c0 [scsi_mod]
    [<ffffffffa000edfb>] scsi_scan+0xdb/0xe0 [scsi_mod]
    [<ffffffffa000ee13>] store_scan+0x13/0x20 [scsi_mod]
    [<ffffffff811c8d9b>] sysfs_write_file+0xcb/0x160
    [<ffffffff811589de>] vfs_write+0xce/0x140
    [<ffffffff81158b53>] sys_write+0x53/0xa0
    [<ffffffff81464592>] system_call_fastpath+0x16/0x1b
    [<00007f611c9d9300>] 0x7f611c9d92ff

    Reported-by: Max Gurtuvoy <maxg@mellanox.com>
    Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
    Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
    Signed-off-by: James Bottomley <JBottomley@Odin.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/scsi/scsi_lib.c | 4 +++-
    include/linux/blk_types.h | 4 +++-
    2 files changed, 6 insertions(+), 2 deletions(-)

    --- a/drivers/scsi/scsi_lib.c
    +++ b/drivers/scsi/scsi_lib.c
    @@ -1311,9 +1311,11 @@ scsi_prep_state_check(struct scsi_device
    "rejecting I/O to dead device\n");
    ret = BLKPREP_KILL;
    break;
    - case SDEV_QUIESCE:
    case SDEV_BLOCK:
    case SDEV_CREATED_BLOCK:
    + ret = BLKPREP_DEFER;
    + break;
    + case SDEV_QUIESCE:
    /*
    * If the devices is blocked we defer normal commands.
    */
    --- a/include/linux/blk_types.h
    +++ b/include/linux/blk_types.h
    @@ -181,7 +181,9 @@ enum rq_flag_bits {
    __REQ_ELVPRIV, /* elevator private data attached */
    __REQ_FAILED, /* set if the request failed */
    __REQ_QUIET, /* don't worry about errors */
    - __REQ_PREEMPT, /* set for "ide_preempt" requests */
    + __REQ_PREEMPT, /* set for "ide_preempt" requests and also
    + for requests for which the SCSI "quiesce"
    + state must be ignored. */
    __REQ_ALLOCED, /* request came from our alloc pool */
    __REQ_COPY_USER, /* contains copies of user pages */
    __REQ_FLUSH_SEQ, /* request for flush sequence */



    \
     
     \ /
      Last update: 2015-04-17 16:21    [W:5.634 / U:0.052 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site