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| author | Bart Van Assche <bart.vanassche@sandisk.com> | 2015-06-05 14:20:51 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-09-13 09:10:50 -0700 |
| commit | 56568d1f973b5167f2941cf05ff92ae48070f09f (patch) | |
| tree | 6d4cf3862aaa714c2d6c164ddce3ca1329e2e895 /drivers | |
| parent | cdef3013688a1f48c440db395b564a66c11f5f72 (diff) | |
| download | lwn-56568d1f973b5167f2941cf05ff92ae48070f09f.tar.gz lwn-56568d1f973b5167f2941cf05ff92ae48070f09f.zip | |
libfc: Fix fc_fcp_cleanup_each_cmd()
commit 8f2777f53e3d5ad8ef2a176a4463a5c8e1a16431 upstream.
Since fc_fcp_cleanup_cmd() can sleep this function must not
be called while holding a spinlock. This patch avoids that
fc_fcp_cleanup_each_cmd() triggers the following bug:
BUG: scheduling while atomic: sg_reset/1512/0x00000202
1 lock held by sg_reset/1512:
#0: (&(&fsp->scsi_pkt_lock)->rlock){+.-...}, at: [<ffffffffc0225cd5>] fc_fcp_cleanup_each_cmd.isra.21+0xa5/0x150 [libfc]
Preemption disabled at:[<ffffffffc0225cd5>] fc_fcp_cleanup_each_cmd.isra.21+0xa5/0x150 [libfc]
Call Trace:
[<ffffffff816c612c>] dump_stack+0x4f/0x7b
[<ffffffff810828bc>] __schedule_bug+0x6c/0xd0
[<ffffffff816c87aa>] __schedule+0x71a/0xa10
[<ffffffff816c8ad2>] schedule+0x32/0x80
[<ffffffffc0217eac>] fc_seq_set_resp+0xac/0x100 [libfc]
[<ffffffffc0218b11>] fc_exch_done+0x41/0x60 [libfc]
[<ffffffffc0225cff>] fc_fcp_cleanup_each_cmd.isra.21+0xcf/0x150 [libfc]
[<ffffffffc0225f43>] fc_eh_device_reset+0x1c3/0x270 [libfc]
[<ffffffff814a2cc9>] scsi_try_bus_device_reset+0x29/0x60
[<ffffffff814a3908>] scsi_ioctl_reset+0x258/0x2d0
[<ffffffff814a2650>] scsi_ioctl+0x150/0x440
[<ffffffff814b3a9d>] sd_ioctl+0xad/0x120
[<ffffffff8132f266>] blkdev_ioctl+0x1b6/0x810
[<ffffffff811da608>] block_ioctl+0x38/0x40
[<ffffffff811b4e08>] do_vfs_ioctl+0x2f8/0x530
[<ffffffff811b50c1>] SyS_ioctl+0x81/0xa0
[<ffffffff816cf8b2>] system_call_fastpath+0x16/0x7a
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/scsi/libfc/fc_fcp.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/drivers/scsi/libfc/fc_fcp.c b/drivers/scsi/libfc/fc_fcp.c index 1d7e76e8b447..ae6fc1a94568 100644 --- a/drivers/scsi/libfc/fc_fcp.c +++ b/drivers/scsi/libfc/fc_fcp.c @@ -1039,11 +1039,26 @@ restart: fc_fcp_pkt_hold(fsp); spin_unlock_irqrestore(&si->scsi_queue_lock, flags); - if (!fc_fcp_lock_pkt(fsp)) { + spin_lock_bh(&fsp->scsi_pkt_lock); + if (!(fsp->state & FC_SRB_COMPL)) { + fsp->state |= FC_SRB_COMPL; + /* + * TODO: dropping scsi_pkt_lock and then reacquiring + * again around fc_fcp_cleanup_cmd() is required, + * since fc_fcp_cleanup_cmd() calls into + * fc_seq_set_resp() and that func preempts cpu using + * schedule. May be schedule and related code should be + * removed instead of unlocking here to avoid scheduling + * while atomic bug. + */ + spin_unlock_bh(&fsp->scsi_pkt_lock); + fc_fcp_cleanup_cmd(fsp, error); + + spin_lock_bh(&fsp->scsi_pkt_lock); fc_io_compl(fsp); - fc_fcp_unlock_pkt(fsp); } + spin_unlock_bh(&fsp->scsi_pkt_lock); fc_fcp_pkt_release(fsp); spin_lock_irqsave(&si->scsi_queue_lock, flags); |