kernel.git/drivers/scsi/st.c, branch linux-4.5.y

Merge branch 'mkp-fixes' into fixes

2015-12-03T17:32:33Z

st: fix potential null pointer dereference.

2015-11-19T17:12:42Z

If cdev_add() returns an error, the code calls cdev_del() passing the STm->cdevs[rew] pointer as parameter; the problem is that the pointer has not been initialized yet. This patch fixes the problem by moving the STm->cdevs[rew] pointer initialization before the call to cdev_add(). It also sets STm->devs[rew] and STm->cdevs[rew] to NULL in case of failure. Signed-off-by: Maurizio Lombardi Reviewed-by: Johannes Thumshirn Reviewed-by: Tomas Henzl Signed-off-by: Martin K. Petersen

st: allow debug output to be enabled or disabled via sysfs

2015-11-10T01:17:27Z

Change st driver to allow enabling or disabling debug output via sysfs file /sys/bus/scsi/drivers/st/debug_flag. Previously the only way to enable debug output was: 1. loading the driver with the module parameter debug_flag=1 2. an ioctl call (this method was also the only way to dynamically disable debug output). To use the ioctl you need a second tape drive (if you are actively testing the first tape drive) since a second process cannot open the first tape drive if it is in use. The this change is only functional if the value of the macro DEBUG in st.c is a non-zero value (which it is by default). Signed-off-by: Shane Seymour Reviewed-by: Laurence Oberman Acked-by: Kai Mäkisara Signed-off-by: James Bottomley

st: Destroy st_index_idr on module exit

2015-08-26T14:45:25Z

Destroy st_index_idr on module exit, reclaiming the allocated memory. This was detected by the following semantic patch (written by Luis Rodriguez ) @ defines_module_init @ declarer name module_init, module_exit; declarer name DEFINE_IDR; identifier init; @@ module_init(init); @ defines_module_exit @ identifier exit; @@ module_exit(exit); @ declares_idr depends on defines_module_init && defines_module_exit @ identifier idr; @@ DEFINE_IDR(idr); @ on_exit_calls_destroy depends on declares_idr && defines_module_exit @ identifier declares_idr.idr, defines_module_exit.exit; @@ exit(void) { ... idr_destroy(&idr); ... } @ missing_module_idr_destroy depends on declares_idr && defines_module_exit && !on_exit_calls_destroy @ identifier declares_idr.idr, defines_module_exit.exit; @@ exit(void) { ... +idr_destroy(&idr); } Signed-off-by: Johannes Thumshirn Reviewed-by: Hannes Reinecke Acked-by: Kai Mäkisara Signed-off-by: James Bottomley

st: convert DRIVER_ATTR macros to DRIVER_ATTR_RO

2015-08-12T22:54:24Z

Convert DRIVER_ATTR macros to DRIVER_ATTR_RO requested by Greg KH. Also switched to using scnprintf instead of snprintf per Documentation/filesystems/sysfs.txt. Suggested-by: Greg Kroah-Hartman Signed-off-by: Shane Seymour Reviewed-by: Hannes Reinecke Reviewed-by: Greg Kroah-Hartman Acked-by: Kai Mäkisara Signed-off-by: James Bottomley

st: convert to using driver attr groups for sysfs

2015-08-12T18:52:05Z

This patch changes the st driver to use attribute groups so driver sysfs files are created automatically. See the following for reference: http://kroah.com/log/blog/2013/06/26/how-to-create-a-sysfs-file-correctly/ Signed-off-by: Shane Seymour Reviewed-by: Greg Kroah-Hartman Acked-by: Kai Mäkisara Signed-off-by: James Bottomley

st: null pointer dereference panic caused by use after kref_put by st_open

2015-07-16T12:32:32Z

Two SLES11 SP3 servers encountered similar crashes simultaneously following some kind of SAN/tape target issue: ... qla2xxx [0000:81:00.0]-801c:3: Abort command issued nexus=3:0:2 -- 1 2002. qla2xxx [0000:81:00.0]-801c:3: Abort command issued nexus=3:0:2 -- 1 2002. qla2xxx [0000:81:00.0]-8009:3: DEVICE RESET ISSUED nexus=3:0:2 cmd=ffff882f89c2c7c0. qla2xxx [0000:81:00.0]-800c:3: do_reset failed for cmd=ffff882f89c2c7c0. qla2xxx [0000:81:00.0]-800f:3: DEVICE RESET FAILED: Task management failed nexus=3:0:2 cmd=ffff882f89c2c7c0. qla2xxx [0000:81:00.0]-8009:3: TARGET RESET ISSUED nexus=3:0:2 cmd=ffff882f89c2c7c0. qla2xxx [0000:81:00.0]-800c:3: do_reset failed for cmd=ffff882f89c2c7c0. qla2xxx [0000:81:00.0]-800f:3: TARGET RESET FAILED: Task management failed nexus=3:0:2 cmd=ffff882f89c2c7c0. qla2xxx [0000:81:00.0]-8012:3: BUS RESET ISSUED nexus=3:0:2. qla2xxx [0000:81:00.0]-802b:3: BUS RESET SUCCEEDED nexus=3:0:2. qla2xxx [0000:81:00.0]-505f:3: Link is operational (8 Gbps). qla2xxx [0000:81:00.0]-8018:3: ADAPTER RESET ISSUED nexus=3:0:2. qla2xxx [0000:81:00.0]-00af:3: Performing ISP error recovery - ha=ffff88bf04d18000. rport-3:0-0: blocked FC remote port time out: removing target and saving binding qla2xxx [0000:81:00.0]-505f:3: Link is operational (8 Gbps). qla2xxx [0000:81:00.0]-8017:3: ADAPTER RESET SUCCEEDED nexus=3:0:2. rport-2:0-0: blocked FC remote port time out: removing target and saving binding sg_rq_end_io: device detached BUG: unable to handle kernel NULL pointer dereference at 00000000000002a8 IP: [] __pm_runtime_idle+0x28/0x90 PGD 7e6586f067 PUD 7e5af06067 PMD 0 [1739975.390354] Oops: 0002 [#1] SMP CPU 0 ... Supported: No, Proprietary modules are loaded [1739975.390463] Pid: 27965, comm: ABCD Tainted: PF X 3.0.101-0.29-default #1 HP ProLiant DL580 Gen8 RIP: 0010:[] [] __pm_runtime_idle+0x28/0x90 RSP: 0018:ffff8839dc1e7c68 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff883f0592fc00 RCX: 0000000000000090 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000138 RBP: 0000000000000138 R08: 0000000000000010 R09: ffffffff81bd39d0 R10: 00000000000009c0 R11: ffffffff81025790 R12: 0000000000000001 R13: ffff883022212b80 R14: 0000000000000004 R15: ffff883022212b80 FS: 00007f8e54560720(0000) GS:ffff88407f800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00000000000002a8 CR3: 0000007e6ced6000 CR4: 00000000001407f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process ABCD (pid: 27965, threadinfo ffff8839dc1e6000, task ffff883592e0c640) Stack: ffff883f0592fc00 00000000fffffffa 0000000000000001 ffff883022212b80 ffff883eff772400 ffffffffa03fa309 0000000000000000 0000000000000000 ffffffffa04003a0 ffff883f063196c0 ffff887f0379a930 ffffffff8115ea1e Call Trace: [] st_open+0x129/0x240 [st] [] chrdev_open+0x13e/0x200 [] __dentry_open+0x198/0x310 [] do_last+0x1f4/0x800 [] path_openat+0xd9/0x420 [] do_filp_open+0x4c/0xc0 [] do_sys_open+0x17f/0x250 [] system_call_fastpath+0x16/0x1b [<00007f8e4f617fd0>] 0x7f8e4f617fcf Code: eb d3 90 48 83 ec 28 40 f6 c6 04 48 89 6c 24 08 4c 89 74 24 20 48 89 fd 48 89 1c 24 4c 89 64 24 10 41 89 f6 4c 89 6c 24 18 74 11 ff 8f 70 01 00 00 0f 94 c0 45 31 ed 84 c0 74 2b 4c 8d a5 a0 RIP [] __pm_runtime_idle+0x28/0x90 RSP CR2: 00000000000002a8 Analysis reveals the cause of the crash to be due to STp->device being NULL. The pointer was NULLed via scsi_tape_put(STp) when it calls scsi_tape_release(). In st_open() we jump to err_out after scsi_block_when_processing_errors() completes and returns the device as offline (sdev_state was SDEV_DEL): 1180 /* Open the device. Needs to take the BKL only because of incrementing the SCSI host 1181 module count. */ 1182 static int st_open(struct inode *inode, struct file *filp) 1183 { 1184 int i, retval = (-EIO); 1185 int resumed = 0; 1186 struct scsi_tape *STp; 1187 struct st_partstat *STps; 1188 int dev = TAPE_NR(inode); 1189 char *name; ... 1217 if (scsi_autopm_get_device(STp->device) < 0) { 1218 retval = -EIO; 1219 goto err_out; 1220 } 1221 resumed = 1; 1222 if (!scsi_block_when_processing_errors(STp->device)) { 1223 retval = (-ENXIO); 1224 goto err_out; 1225 } ... 1264 err_out: 1265 normalize_buffer(STp->buffer); 1266 spin_lock(&st_use_lock); 1267 STp->in_use = 0; 1268 spin_unlock(&st_use_lock); 1269 scsi_tape_put(STp); <-- STp->device = 0 after this 1270 if (resumed) 1271 scsi_autopm_put_device(STp->device); 1272 return retval; The ref count for the struct scsi_tape had already been reduced to 1 when the .remove method of the st module had been called. The kref_put() in scsi_tape_put() caused scsi_tape_release() to be called: 0266 static void scsi_tape_put(struct scsi_tape *STp) 0267 { 0268 struct scsi_device *sdev = STp->device; 0269 0270 mutex_lock(&st_ref_mutex); 0271 kref_put(&STp->kref, scsi_tape_release); <-- calls this 0272 scsi_device_put(sdev); 0273 mutex_unlock(&st_ref_mutex); 0274 } In scsi_tape_release() the struct scsi_device in the struct scsi_tape gets set to NULL: 4273 static void scsi_tape_release(struct kref *kref) 4274 { 4275 struct scsi_tape *tpnt = to_scsi_tape(kref); 4276 struct gendisk *disk = tpnt->disk; 4277 4278 tpnt->device = NULL; <<<---- where the dev is nulled 4279 4280 if (tpnt->buffer) { 4281 normalize_buffer(tpnt->buffer); 4282 kfree(tpnt->buffer->reserved_pages); 4283 kfree(tpnt->buffer); 4284 } 4285 4286 disk->private_data = NULL; 4287 put_disk(disk); 4288 kfree(tpnt); 4289 return; 4290 } Although the problem was reported on SLES11.3 the problem appears in linux-next as well. The crash is fixed by reordering the code so we no longer access the struct scsi_tape after the kref_put() is done on it in st_open(). Signed-off-by: Shane Seymour Signed-off-by: Darren Lavender Reviewed-by: Johannes Thumshirn Acked-by: Kai Mäkisara Cc: stable@vger.kernel.org Signed-off-by: James Bottomley

st: implement tape statistics

2015-06-02T15:03:25Z

This patch implements tape statistics in the st module via sysfs. Current no statistics are available for tape I/O and there is no easy way to reuse the block layer statistics for tape as tape is a character device and does not have perform I/O in sector sized chunks (the size of the data written to tape can change). For tapes we also need extra stats related to things like tape movement (via other I/O). There have been multiple end users requesting statistics including AT&T (and some HP customers who have not given permission to be named). It is impossible for them to investigate any issues related to tape performance in a non-invasive way. [jejb: eliminate PRId64] Signed-off-by: Shane Seymour Tested-by: Shane Seymour Reviewed-by: Christoph Hellwig Signed-off-by: James Bottomley

mm: gup: use get_user_pages_unlocked

2015-02-12T01:06:05Z

This allows those get_user_pages calls to pass FAULT_FLAG_ALLOW_RETRY to the page fault in order to release the mmap_sem during the I/O. Signed-off-by: Andrea Arcangeli Reviewed-by: Kirill A. Shutemov Cc: Andres Lagar-Cavilla Cc: Peter Feiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

scsi: remove scsi_driver owner field

2014-11-24T19:01:28Z

The driver core driver structure has grown an owner field and now requires it to be set for all modular drivers. Set it up for all scsi_driver instances and get rid of the now superflous scsi_driver owner field. Signed-off-by: Christoph Hellwig Reported-by: Shane M Seymour Reviewed-by: Ewan D. Milne