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path: root/drivers/md/dm-mpath.c
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2008-10-01dm mpath: add missing path switching lockingChandra Seetharaman
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: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-07-26[SCSI] scsi_dh: attach to hardware handler from dm-mpathHannes Reinecke
multipath keeps a separate device table which may be more current than the built-in one. So we should make sure to always call ->attach whenever a multipath map with hardware handler is instantiated. And we should call ->detach on removal, too. [sekharan: update as per comments from agk] Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-21dm mpath: fix test for reinstate_pathAlasdair G Kergon
Fix test for reinstate_path method before attempting to use it. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Julia Lawall <julia@diku.dk>
2008-07-21dm mpath: return parameter errorMikulas Patocka
Return a specific error message if there are an invalid number of multipath arguments. This invalid command returns an "Unknown error" because the ti->error field is not set dmsetup create --table '0 2 multipath 0 0 1 1 round-robin 0 1 1 /dev/sdh' mpath0 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-07-21dm mpath: free path selector on invalid argsMikulas Patocka
Free path selector if the arguments are invalid. This command (note that it is invalid) causes reference leak on module "dm_round_robin" and prevents the module from being removed. dmsetup create --table '0 2 multipath 0 0 1 1 round-robin /dev/sdh' mpath0 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-07-15[SCSI] scsi_dh: fix kconfig related build errorsChandra Seetharaman
Do not automatically "select" SCSI_DH for dm-multipath. If SCSI_DH doesn't exist,just do not allow hardware handlers to be used. Handle SCSI_DH being a module also. Make sure it doesn't allow DM_MULTIPATH to be compiled in when SCSI_DH is a module. [jejb: added comment for Kconfig syntax] Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Reported-by: Randy Dunlap <randy.dunlap@oracle.com> Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05[SCSI] scsi_dh: Remove dm_pg_init_completeChandra Seetharaman
This patch just removes the dm layer's path initialization completion routine. This is separated from the other patch(scsi_dh: Use SCSI device handler in dm-multipath) Just to make that patch more readable. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Acked-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05[SCSI] scsi_dh: Add a single threaded workqueue for initializing pathsChandra Seetharaman
Before this patch set (SCSI hardware handlers), initialization of a path was done asynchronously. Doing that requires a workqueue in each device/hardware handler module and leads to unneccessary complication in the device handler code, making it difficult to read the code and follow the state diagram. Moving that workqueue to this level makes the device handler code simpler. Hence, the workqueue is moved to dm level. A new workqueue is added instead of adding it to the existing workqueue (kmpathd) for the following reasons: 1. Device activation has to happen faster, stacking them along with the other workqueue might lead to unnecessary delay in the activation of the path. 2. The effect could be felt the other way too. i.e the current events that are handled by the existing workqueue might get a delayed response. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Acked-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05[SCSI] scsi_dh: Use SCSI device handler in dm-multipathChandra Seetharaman
This patch converts dm-mpath to use scsi device handlers instead of dm's hardware handlers. This patch does not add any new functionality. Old behaviors remain and userspace tools work as is except that arguments supplied with hardware handler are ignored. One behavioral exception is: Activation of a path is synchronous in this patch, opposed to the older behavior of being asynchronous (changed in patch 07: scsi_dh: Add a single threaded workqueue for initializing a path) Note: There is no need to get a reference for the device handler module (as it was done in the dm hardware handler case) here as the reference is held when the device was first found. Instead we check and make sure that support for the specified device is present at table load time. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Acked-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-02-08dm mpath: add missing staticAlasdair G Kergon
A static declaration missing. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2007-10-20dm mpath: send ueventsMike Anderson
This patch adds calls to dm_path_event for a failed path and a reinstated path. Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2007-10-20dm mpath: add retry pg initDave Wysochanski
This patch allows a failed path group initialisation command to be retried. It adds a generic MP_RETRY flag and a "pg_init_retries" feature to device-mapper multipath which limits the number of retries. 1. A hw handler sends a path initialization command to the storage and the command completes with an error code indicating the command should be retried. 2. The hardware handler calls dm_pg_init_complete() with MP_RETRY set in err_flags to ask the dm multipath core to retry. 3. If the retry limit has not been exceeded, pg_init() is retried. Otherwise fail_path() is called. If you are using the userspace multipath-tools or device-mapper-multipath package, you can set pg_init_retries in the 'device' section of your /etc/multipath.conf file. For example: features "2 pg_init_retries 7" The number of PG retries attempted is reported in the 'dmsetup status' output. Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Acked-by: Mike Christie <michaelc@cs.wisc.edu> Acked-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2007-10-10Drop 'size' argument from bio_endio and bi_end_ioNeilBrown
As bi_end_io is only called once when the reqeust is complete, the 'size' argument is now redundant. Remove it. Now there is no need for bio_endio to subtract the size completed from bi_size. So don't do that either. While we are at it, change bi_end_io to return void. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-07-12dm: disable barriersStefan Bader
This patch causes device-mapper to reject any barrier requests. This is done since most of the targets won't handle this correctly anyway. So until the situation improves it is better to reject these requests at the first place. Since barrier requests won't get to the targets, the checks there can be removed. Cc: stable@kernel.org Signed-off-by: Stefan Bader <shbader@de.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-12dm: remove duplicate module name from error msgsAlasdair G Kergon
Remove explicit module name from messages as the macro now includes it automatically. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-12dm: use kmem_cache macroAlasdair G Kergon
Use new KMEM_CACHE() macro and make the newly-exposed structure names more meaningful. Also remove some superfluous casts and inlines (let a modern compiler be the judge). Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09dm mpath: log device nameEdward Goggin
Make the mapped device structure accessible to hardware handlers so error messages can include the device name. Signed-off-by: Edward Goggin <egoggin@emc.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-08[PATCH] dm: mpath: use noflush suspendingKiyoshi Ueda
Implement the pushback feature for the multipath target. The pushback request is used when: 1) there are no valid paths; 2) queue_if_no_path was set; 3) a suspend is being issued with the DMF_NOFLUSH_SUSPENDING flag. Otherwise bios are returned to applications with -EIO. To check whether queue_if_no_path is specified or not, you need to check both queue_if_no_path and saved_queue_if_no_path, because presuspend saves the original queue_if_no_path value to saved_queue_if_no_path. The check for 1 already exists in both map_io() and do_end_io(). So this patch adds __must_push_back() to check 2 and 3. Test results: See the test results in the preceding patch. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: dm-devel@redhat.com Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] dm: map and endio symbolic return codesKiyoshi Ueda
Update existing targets to use the new symbols for return values from target map and end_io functions. There is no effect on behaviour. Test results: Done build test without errors. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: dm-devel@redhat.com Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] struct path: convert mdJosef Sipek
Signed-off-by: Josef Sipek <jsipek@fsl.cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] struct path: rename DM's struct pathJosef "Jeff" Sipek
Rename DM's struct path to struct dm_path to prevent name collision between it and struct path from fs/namei.c. Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu> Acked-by: Alasdair G Kergon <agk@redhat.com> Cc: <reiserfs-dev@namesys.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07[PATCH] slab: remove kmem_cache_tChristoph Lameter
Replace all uses of kmem_cache_t with struct kmem_cache. The patch was generated using the following script: #!/bin/sh # # Replace one string by another in all the kernel sources. # set -e for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do quilt add $file sed -e "1,\$s/$1/$2/g" $file >/tmp/$$ mv /tmp/$$ $file quilt refresh done The script was run like this sh replace kmem_cache_t "struct kmem_cache" Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-22WorkStruct: make allyesconfigDavid Howells
Fix up for make allyesconfig. Signed-Off-By: David Howells <dhowells@redhat.com>
2006-10-03[PATCH] dm mpath: use kzallocMicha³ Miros³aw
Use kzalloc() instead of kmalloc() + memset(). Signed-off-by: Micha³ Miros³aw <mirq-linux@rere.qmqm.pl> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03[PATCH] dm mpath: tidy ctrMicha³ Miros³aw
After initialising m->ti, there's no need to pass it in subsequent calls to static functions used for parsing parameters. Signed-off-by: Micha³ Miros³aw <mirq-linux@rere.qmqm.pl> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03[PATCH] dm: support ioctls on mapped devices: fix with fake fileMilan Broz
The new ioctl code passes the wrong file pointer to the underlying device. No file pointer is available so make a temporary fake one. ioctl_by_bdev() does set_fs(KERNEL_DS) so it's for ioctls originating within the kernel and unsuitable here. We are processing ioctls that originated in userspace and mapping them to different devices. Fixing the existing callers that pass a NULL file struct and consolidating the fake_file users are separate matters to solve in later patches. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03[PATCH] dm: export blkdev_driver_ioctlAlasdair G Kergon
Export blkdev_driver_ioctl for device-mapper. If we get as far as the device-mapper ioctl handler, we know the ioctl is not a standard block layer BLK* one, so we don't need to check for them a second time and can call blkdev_driver_ioctl() directly. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03[PATCH] dm mpath: support ioctlsMilan Broz
When an ioctl is performed on a multipath device simply pass it on to the underlying block device through current_path. If current path is not yet selected, select it. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-14[PATCH] dm: BUG/OOPS fixMichal Miroslaw
Fix BUG I tripped on while testing failover and multipathing. BUG shows up on error path in multipath_ctr() when parse_priority_group() fails after returning at least once without error. The fix is to initialize m->ti early - just after alloc()ing it. BUG: unable to handle kernel NULL pointer dereference at virtual address 00000000 printing eip: c027c3d2 *pde = 00000000 Oops: 0000 [#3] Modules linked in: qla2xxx ext3 jbd mbcache sg ide_cd cdrom floppy CPU: 0 EIP: 0060:[<c027c3d2>] Not tainted VLI EFLAGS: 00010202 (2.6.17.3 #1) EIP is at dm_put_device+0xf/0x3b eax: 00000001 ebx: ee4fcac0 ecx: 00000000 edx: ee4fcac0 esi: ee4fc4e0 edi: ee4fc4e0 ebp: 00000000 esp: c5db3e78 ds: 007b es: 007b ss: 0068 Process multipathd (pid: 15912, threadinfo=c5db2000 task=ef485a90) Stack: ec4eda40 c02816bd ee4fc4c0 00000000 f7e89498 f883e0bc c02816f6 f7e89480 f7e8948c c0281801 ffffffea f7e89480 f883e080 c0281ffe 00000001 00000000 00000004 dfe9cab8 f7a693c0 f883e080 f883e0c0 ca4b99c0 c027c6ee 01400000 Call Trace: <c02816bd> free_pgpaths+0x31/0x45 <c02816f6> free_priority_group+0x25/0x2e <c0281801> free_multipath+0x35/0x67 <c0281ffe> multipath_ctr+0x123/0x12d <c027c6ee> dm_table_add_target+0x11e/0x18b <c027e5b4> populate_table+0x8a/0xaf <c027e62b> table_load+0x52/0xf9 <c027ec23> ctl_ioctl+0xca/0xfc <c027e5d9> table_load+0x0/0xf9 <c0152146> do_ioctl+0x3e/0x43 <c0152360> vfs_ioctl+0x16c/0x178 <c01523b4> sys_ioctl+0x48/0x60 <c01029b3> syscall_call+0x7/0xb Code: 97 f0 00 00 00 89 c1 83 c9 01 80 e2 01 0f 44 c1 88 43 14 8b 04 24 59 5b 5e 5f 5d c3 53 89 c1 89 d3 ff 4a 08 0f 94 c0 84 c0 74 2a <8b> 01 8b 10 89 d8 e8 f6 fb ff ff 8b 03 8b 53 04 89 50 04 89 02 EIP: [<c027c3d2>] dm_put_device+0xf/0x3b SS:ESP 0068:c5db3e78 Signed-off-by: Michal Miroslaw <mirq-linux@rere.qmqm.pl> Acked-by: Alasdair G Kergon <agk@redhat.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26[PATCH] dm: improve error message consistencyAlasdair G Kergon
Tidy device-mapper error messages to include context information automatically. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26[PATCH] mempool: use mempool_create_slab_pool()Matthew Dobson
Modify well over a dozen mempool users to call mempool_create_slab_pool() rather than calling mempool_create() with extra arguments, saving about 30 lines of code and increasing readability. Signed-off-by: Matthew Dobson <colpatch@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-22[PATCH] device-mapper dm-mpath: endio spinlock fixStefan Bader
do_end_io() can be called without interrupts blocked. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-28[PATCH] device-mapper: Fix queue_if_no_path initialisationAlasdair G Kergon
When creating a multipath device, if the queue_if_no_path parameter is specified it gets ignored. While the queue_if_no_path variable is correctly set to 1, the saved_queue_if_no_path gets set to 0. When the device is subsequently made live (resumed), the saved value (0) always overwrites the live value (1) so the option *always* gets turned off. The fix adds a parameter to the queue_if_no_path() function to indicate whether the previous value should be preserved or not - if not, as when the device is being set up, the saved value is set to the new value (1). Signed-Off-By: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-12[PATCH] device-mapper multipath: Fix pg initialisation racesAlasdair G Kergon
Prevent more than one priority group initialisation function from being outstanding at once. Otherwise the completion functions interfere with each other. Also, reloading the table could reference a freed pointer. Only reset queue_io in pg_init_complete if another pg_init isn't required. Skip process_queued_ios if the queue is empty so that we only trigger a pg_init if there's I/O. Signed-off-by: Lars Marowsky-Bree <lmb@suse.de> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-12[PATCH] device-mapper multipath: Avoid possible suspension deadlockAlasdair G Kergon
To avoid deadlock when suspending a multipath device after all its paths have failed, stop queueing any I/O that is about to fail *before* calling freeze_bdev instead of after. Instead of setting a multipath 'suspended' flag which would have to be reset if an error occurs during the process, save the previous queueing state and leave userspace to restore if it wishes. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-12[PATCH] device-mapper multipath: Flush workqueue when destroyingAlasdair G Kergon
The multipath destructor must flush its workqueue. Otherwise items that reference the destroyed object could remain. From: "goggin, edward" <egoggin@emc.com> Signed-off-by: Lars Marowsky-Bree <lmb@suse.de> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-12[PATCH] device-mapper multipath: Barriers not supportedAlasdair G Kergon
dm multipath will report barriers as not supported with this patch. Signed-off-by: Lars Marowsky-Bree <lmb@suse.de> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-08[PATCH] dm: Handle READA requests in dm-mpath.cLars Marowsky-Bree
READA errors failing with EWOULDBLOCK/EAGAIN do not constitute a valid reason for failing the path; this lead to erratic errors on DM multipath devices. This error can be safely propagated upwards without failing the path. Acked-by: Kevin Corry <kevcorry@us.ibm.com> Acked-by: Jens Axboe <axboe@suse.de> Signed-off-by: Lars Marowsky-Bree <lmb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-05[PATCH] device-mapper multipath: Use private workqueueAlasdair G Kergon
dm-mpath.c needs to use a private workqueue (like other dm targets already do) to avoid interfering with users of the default workqueue. Signed-Off-By: Alasdair G Kergon <agk@redhat.com> Acked-by: Jens Axboe <axboe@suse.de> Signed-off-by: Lars Marowsky-Bree <lmb@suse.de> Signed-off-by: <mikenc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!