linux/block, branch v3.2.2

block: fail SCSI passthrough ioctls on partition devices

2012-01-26T00:13:42Z

commit 0bfc96cb77224736dfa35c3c555d37b3646ef35e upstream. [ Changes with respect to 3.3: return -ENOTTY from scsi_verify_blk_ioctl and -ENOIOCTLCMD from sd_compat_ioctl. ] Linux allows executing the SG_IO ioctl on a partition or LVM volume, and will pass the command to the underlying block device. This is well-known, but it is also a large security problem when (via Unix permissions, ACLs, SELinux or a combination thereof) a program or user needs to be granted access only to part of the disk. This patch lets partitions forward a small set of harmless ioctls; others are logged with printk so that we can see which ioctls are actually sent. In my tests only CDROM_GET_CAPABILITY actually occurred. Of course it was being sent to a (partition on a) hard disk, so it would have failed with ENOTTY and the patch isn't changing anything in practice. Still, I'm treating it specially to avoid spamming the logs. In principle, this restriction should include programs running with CAP_SYS_RAWIO. If for example I let a program access /dev/sda2 and /dev/sdb, it still should not be able to read/write outside the boundaries of /dev/sda2 independent of the capabilities. However, for now programs with CAP_SYS_RAWIO will still be allowed to send the ioctls. Their actions will still be logged. This patch does not affect the non-libata IDE driver. That driver however already tests for bd != bd->bd_contains before issuing some ioctl; it could be restricted further to forbid these ioctls even for programs running with CAP_SYS_ADMIN/CAP_SYS_RAWIO. Cc: linux-scsi@vger.kernel.org Cc: Jens Axboe Cc: James Bottomley Signed-off-by: Paolo Bonzini [ Make it also print the command name when warning - Linus ] Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

block: add and use scsi_blk_cmd_ioctl

2012-01-26T00:13:42Z

commit 577ebb374c78314ac4617242f509e2f5e7156649 upstream. Introduce a wrapper around scsi_cmd_ioctl that takes a block device. The function will then be enhanced to detect partition block devices and, in that case, subject the ioctls to whitelisting. Cc: linux-scsi@vger.kernel.org Cc: Jens Axboe Cc: James Bottomley Signed-off-by: Paolo Bonzini Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

block: fix blk_queue_end_tag()

2011-12-29T08:16:28Z

Commit 5e081591 "block: warn if tag is greater than real_max_depth" cleaned up blk_queue_end_tag() to warn when the tag is truly invalid (greater than real_max_depth). However, it changed behavior in the tag < max_depth case to not end the request. Leading to triggering of BUG_ON(blk_queued_rq(rq)) in the request completion path: http://marc.info/?l=linux-kernel&m=132204370518629&w=2 In order to allow blk_queue_resize_tags() to shrink the tag space blk_queue_end_tag() must always complete tags with a value less than real_max_depth regardless of the current max_depth. The comment about "handling the shrink case" seems to be what prompted changes in this space, so remove it and BUG on all invalid tags (made even simpler by Matthew's suggestion to use an unsigned compare). Signed-off-by: Dan Williams Cc: Tao Ma Cc: Matthew Wilcox Reported-by: Meelis Roos Reported-by: Ed Nadolski Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Jens Axboe

block: re-use existing 'reading' variable instead of checking direction again

2011-12-21T14:27:24Z

Signed-off-by: majianpeng Signed-off-by: Jens Axboe

block, cfq: fix empty queue crash caused by request merge

2011-12-16T13:04:23Z

All requests of a queue could be merged to other requests of other queue. Such queue will not have request in it, but it's in service tree. This will cause kernel oops. I encounter a BUG_ON() in cfq_dispatch_request() with next patch, but the issue should exist without the patch. Signed-off-by: Shaohua Li Signed-off-by: Jens Axboe

block: don't kick empty queue in blk_drain_queue()

2011-12-15T19:03:04Z

While probing, fd sets up queue, probes hardware and tears down the queue if probing fails. In the process, blk_drain_queue() kicks the queue which failed to finish initialization and fd is unhappy about that. floppy0: no floppy controllers found ------------[ cut here ]------------ WARNING: at drivers/block/floppy.c:2929 do_fd_request+0xbf/0xd0() Hardware name: To Be Filled By O.E.M. VFS: do_fd_request called on non-open device Modules linked in: Pid: 1, comm: swapper Not tainted 3.2.0-rc4-00077-g5983fe2 #2 Call Trace: [] warn_slowpath_common+0x7a/0xb0 [] warn_slowpath_fmt+0x41/0x50 [] do_fd_request+0xbf/0xd0 [] blk_drain_queue+0x65/0x80 [] blk_cleanup_queue+0xe3/0x1a0 [] floppy_init+0xdeb/0xe28 [] ? daring+0x6b/0x6b [] do_one_initcall+0x3f/0x170 [] kernel_init+0x9d/0x11e [] ? schedule_tail+0x22/0xa0 [] kernel_thread_helper+0x4/0x10 [] ? start_kernel+0x2be/0x2be [] ? gs_change+0xb/0xb Avoid it by making blk_drain_queue() kick queue iff dispatch queue has something on it. Signed-off-by: Tejun Heo Reported-by: Ralf Hildebrandt Reported-by: Wu Fengguang Tested-by: Sergei Trofimovich Signed-off-by: Jens Axboe

cfq-iosched: fix cfq_cic_link() race confition

2011-12-02T09:07:07Z

cfq_cic_link() has race condition. When some processes which shared ioc issue I/O to same block device simultaneously, cfq_cic_link() returns -EEXIST sometimes. The race condition might stop I/O by following steps: step 1: Process A: Issue an I/O to /dev/sda step 2: Process A: Get an ioc (iocA here) in get_io_context() which does not linked with a cic for the device step 3: Process A: Get a new cic for the device (cicA here) in cfq_alloc_io_context() step 4: Process B: Issue an I/O to /dev/sda step 5: Process B: Get iocA in get_io_context() since process A and B share the same ioc step 6: Process B: Get a new cic for the device (cicB here) in cfq_alloc_io_context() since iocA has not been linked with a cic for the device yet step 7: Process A: Link cicA to iocA in cfq_cic_link() step 8: Process A: Dispatch I/O to driver and finish it step 9: Process B: Try to link cicB to iocA in cfq_cic_link() But it fails with showing "cfq: cic link failed!" kernel message, since iocA has already linked with cicA at step 7. step 10: Process B: Wait for finishig I/O in get_request_wait() The function does not wake up, when there is no I/O to the device. When cfq_cic_link() returns -EEXIST, it means ioc has already linked with cic. So when cfq_cic_link() return -EEXIST, retry cfq_cic_lookup(). Signed-off-by: Yasuaki Ishimatsu Cc: stable@kernel.org Signed-off-by: Jens Axboe

cfq-iosched: free cic_index if blkio_alloc_blkg_stats fails

2011-11-30T14:47:48Z

If we fail allocating the blkpg stats, we free cfqd and cfgq. But we need to free the IDA cfqd->cic_index as well. Signed-off-by: majianpeng Cc: stable@kernel.org Signed-off-by: Jens Axboe

block: initialize request_queue's numa node during

2011-11-23T09:59:13Z

struct request_queue is allocated with __GFP_ZERO so its "node" field is zero before initialization. This causes an oops if node 0 is offline in the page allocator because its zonelists are not initialized. From Dave Young's dmesg: SRAT: Node 1 PXM 2 0-d0000000 SRAT: Node 1 PXM 2 100000000-330000000 SRAT: Node 0 PXM 1 330000000-630000000 Initmem setup node 1 0000000000000000-000000000affb000 ... Built 1 zonelists in Node order, mobility grouping on. ... BUG: unable to handle kernel paging request at 0000000000001c08 IP: [] __alloc_pages_nodemask+0xb5/0x870 and __alloc_pages_nodemask+0xb5 translates to a NULL pointer on zonelist->_zonerefs. The fix is to initialize q->node at the time of allocation so the correct node is passed to the slab allocator later. Since blk_init_allocated_queue_node() is no longer needed, merge it with blk_init_allocated_queue(). [rientjes@google.com: changelog, initializing q->node] Cc: stable@vger.kernel.org [2.6.37+] Reported-by: Dave Young Signed-off-by: Mike Snitzer Signed-off-by: David Rientjes Tested-by: Dave Young Signed-off-by: Jens Axboe

block: add missed trace_block_plug

2011-11-16T08:21:50Z

After flush plug list, the list has no request, so we need to add a trace_block_plug(). Signed-off-by: Shaohua Li Reviewed-by: Namhyung Kim Signed-off-by: Andrew Morton Signed-off-by: Jens Axboe