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2022-05-02dlm: use kref_put_lock in __put_lkbAlexander Aring1-6/+6
This patch will optimize __put_lkb() by using kref_put_lock(). The function kref_put_lock() will only take the lock if the reference is going to be zero, if not the lock will never be held. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-05-02dlm: use kref_put_lock in put_rsbAlexander Aring1-3/+5
This patch will optimize put_rsb() by using kref_put_lock(). The function kref_put_lock() will only take the lock if the reference is going to be zero, if not the lock will never be held. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-05-02dlm: remove unnecessary error assignAlexander Aring1-3/+0
This patch removes unnecessary error assigns to 0 at places we know that error is zero because it was checked on non-zero before. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-05-02dlm: fix missing lkb refcount handlingAlexander Aring1-2/+9
We always call hold_lkb(lkb) if we increment lkb->lkb_wait_count. So, we always need to call unhold_lkb(lkb) if we decrement lkb->lkb_wait_count. This patch will add missing unhold_lkb(lkb) if we decrement lkb->lkb_wait_count. In case of setting lkb->lkb_wait_count to zero we need to countdown until reaching zero and call unhold_lkb(lkb). The waiters list unhold_lkb(lkb) can be removed because it's done for the last lkb_wait_count decrement iteration as it's done in _remove_from_waiters(). This issue was discovered by a dlm gfs2 test case which use excessively dlm_unlock(LKF_CANCEL) feature. Probably the lkb->lkb_wait_count value never reached above 1 if this feature isn't used and so it was not discovered before. The testcase ended in a rsb on the rsb keep data structure with a refcount of 1 but no lkb was associated with it, which is itself an invalid behaviour. A side effect of that was a condition in which the dlm was sending remove messages in a looping behaviour. With this patch that has not been reproduced. Cc: stable@vger.kernel.org Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-07fs: dlm: cast resource pointer to uintptr_tAlexander Aring1-1/+1
This patch fixes the following warning when doing a 32 bit kernel build when pointers are 4 byte long: In file included from ./include/linux/byteorder/little_endian.h:5, from ./arch/x86/include/uapi/asm/byteorder.h:5, from ./include/asm-generic/qrwlock_types.h:6, from ./arch/x86/include/asm/spinlock_types.h:7, from ./include/linux/spinlock_types_raw.h:7, from ./include/linux/ratelimit_types.h:7, from ./include/linux/printk.h:10, from ./include/asm-generic/bug.h:22, from ./arch/x86/include/asm/bug.h:87, from ./include/linux/bug.h:5, from ./include/linux/mmdebug.h:5, from ./include/linux/gfp.h:5, from ./include/linux/slab.h:15, from fs/dlm/dlm_internal.h:19, from fs/dlm/rcom.c:12: fs/dlm/rcom.c: In function ‘dlm_send_rcom_lock’: ./include/uapi/linux/byteorder/little_endian.h:32:43: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] #define __cpu_to_le64(x) ((__force __le64)(__u64)(x)) ^ ./include/linux/byteorder/generic.h:86:21: note: in expansion of macro ‘__cpu_to_le64’ #define cpu_to_le64 __cpu_to_le64 ^~~~~~~~~~~~~ fs/dlm/rcom.c:457:14: note: in expansion of macro ‘cpu_to_le64’ rc->rc_id = cpu_to_le64(r); The rc_id value in dlm rcom is handled as u64. The rcom implementation uses for an unique number generation the pointer value of the used dlm_rsb instance. However if the pointer value is 4 bytes long -Wpointer-to-int-cast will print a warning. We get rid of that warning to cast the pointer to uintptr_t which is either 4 or 8 bytes. There might be a very unlikely case where this number isn't unique anymore if using dlm in a mixed cluster of nodes and sizeof(uintptr_t) returns 4 and 8. However this problem was already been there and this patch should get rid of the warning. Fixes: 2f9dbeda8dc0 ("dlm: use __le types for rcom messages") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: replace usage of found with dedicated list iterator variableJakob Koschel3-60/+56
To move the list iterator variable into the list_for_each_entry_*() macro in the future it should be avoided to use the list iterator variable after the loop body. To *never* use the list iterator variable after the loop it was concluded to use a separate iterator variable instead of a found boolean [1]. This removes the need to use a found variable and simply checking if the variable was set, can determine if the break/goto was hit. Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1] Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: remove usage of list iterator for list_add() after the loop bodyJakob Koschel1-4/+8
In preparation to limit the scope of a list iterator to the list traversal loop, use a dedicated pointer to point to the found element [1]. Before, the code implicitly used the head when no element was found when using &pos->list. Since the new variable is only set if an element was found, the list_add() is performed within the loop and only done after the loop if it is done on the list head directly. Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1] Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: fix pending remove if msg allocation failsAlexander Aring1-1/+2
This patch unsets ls_remove_len and ls_remove_name if a message allocation of a remove messages fails. In this case we never send a remove message out but set the per ls ls_remove_len ls_remove_name variable for a pending remove. Unset those variable should indicate possible waiters in wait_pending_remove() that no pending remove is going on at this moment. Cc: stable@vger.kernel.org Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: fix wake_up() calls for pending removeAlexander Aring1-2/+2
This patch move the wake_up() call at the point when a remove message completed. Before it was only when a remove message was going to be sent. The possible waiter in wait_pending_remove() waits until a remove is done if the resource name matches with the per ls variable ls->ls_remove_name. If this is the case we must wait until a pending remove is done which is indicated if DLM_WAIT_PENDING_COND() returns false which will always be the case when ls_remove_len and ls_remove_name are unset to indicate that a remove is not going on anymore. Fixes: 21d9ac1a5376 ("fs: dlm: use event based wait for pending remove") Cc: stable@vger.kernel.org Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: check required context while closeAlexander Aring3-0/+16
This patch adds a WARN_ON() check to validate the right context while dlm_midcomms_close() is called. Even before commit 489d8e559c65 ("fs: dlm: add reliable connection if reconnect") in this context dlm_lowcomms_close() flushes all ongoing transmission triggered by dlm application stack. If we do that, it's required that no new message will be triggered by the dlm application stack. The function dlm_midcomms_close() is not called often so we can check if all lockspaces are in such context. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: cleanup lock handling in dlm_master_lookupAlexander Aring1-87/+102
This patch will remove the following warning by sparse: fs/dlm/lock.c:1049:9: warning: context imbalance in 'dlm_master_lookup' - different lock contexts for basic block I tried to find any issues with the current handling and I did not find any. However it is hard to follow the lock handling in this area of dlm_master_lookup() and I suppose that sparse cannot realize that there are no issues. The variable "toss_list" makes it really hard to follow the lock handling because if it's set the rsb lock/refcount isn't held but the ls->ls_rsbtbl[b].lock is held and this is one reason why the rsb lock/refcount does not need to be held. If it's not set the ls->ls_rsbtbl[b].lock is not held but the rsb lock/refcount is held. The indicator of toss_list will be used to store the actual lock state. Another possibility is that a retry can happen and then it's hard to follow the specific code part. I did not find any issues but sparse cannot realize that there are no issues. To make it more easier to understand for developers and sparse as well, we remove the toss_list variable which indicates a specific lock state and move handling in between of this lock state in a separate function. This function can be called now in case when the initial lock states are taken which was previously signalled if toss_list was set or not. The advantage here is that we can release all locks/refcounts in mostly the same code block as it was taken. Afterwards sparse had no issues to figure out that there are no problems with the current lock behaviour. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: remove found label in dlm_master_lookupAlexander Aring1-9/+9
This patch cleanups a not necessary label found which can be replaced by a proper else handling to jump over a specific code block. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: remove __user conversion warningsAlexander Aring1-8/+8
This patch avoids the following sparse warning: fs/dlm/user.c:111:38: warning: incorrect type in assignment (different address spaces) fs/dlm/user.c:111:38: expected void [noderef] __user *castparam fs/dlm/user.c:111:38: got void * fs/dlm/user.c:112:37: warning: incorrect type in assignment (different address spaces) fs/dlm/user.c:112:37: expected void [noderef] __user *castaddr fs/dlm/user.c:112:37: got void * fs/dlm/user.c:113:38: warning: incorrect type in assignment (different address spaces) fs/dlm/user.c:113:38: expected void [noderef] __user *bastparam fs/dlm/user.c:113:38: got void * fs/dlm/user.c:114:37: warning: incorrect type in assignment (different address spaces) fs/dlm/user.c:114:37: expected void [noderef] __user *bastaddr fs/dlm/user.c:114:37: got void * fs/dlm/user.c:115:33: warning: incorrect type in assignment (different address spaces) fs/dlm/user.c:115:33: expected struct dlm_lksb [noderef] __user *lksb fs/dlm/user.c:115:33: got void * fs/dlm/user.c:130:39: warning: cast removes address space '__user' of expression fs/dlm/user.c:131:40: warning: cast removes address space '__user' of expression fs/dlm/user.c:132:36: warning: cast removes address space '__user' of expression So far I see there is no direct handling of copying a pointer value to another pointer value. The handling only copies the actual pointer address to a scalar type or vice versa. This should be okay because it never handles dereferencing anything of those addresses in the kernel space. To get rid of those warnings we doing some different casting which results in no warnings in sparse or compiler. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: move conversion to compile timeAlexander Aring1-10/+10
This patch is a cleanup to move the byte order conversion to compile time. In a simple comparison like this it's possible to move it to static values so the compiler will always convert those values at compile time. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: use __le types for dlm messagesAlexander Aring5-205/+174
This patch changes to use __le types directly in the dlm message structure which is casted at the right dlm message buffer positions. The main goal what is reached here is to remove sparse warnings regarding to host to little byte order conversion or vice versa. Leaving those sparse issues ignored and always do it in out/in functionality tends to leave it unknown in which byte order the variable is being handled. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: use __le types for rcom messagesAlexander Aring7-80/+52
This patch changes to use __le types directly in the dlm rcom structure which is casted at the right dlm message buffer positions. The main goal what is reached here is to remove sparse warnings regarding to host to little byte order conversion or vice versa. Leaving those sparse issues ignored and always do it in out/in functionality tends to leave it unknown in which byte order the variable is being handled. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: use __le types for dlm headerAlexander Aring9-116/+98
This patch changes to use __le types directly in the dlm header structure which is casted at the right dlm message buffer positions. The main goal what is reached here is to remove sparse warnings regarding to host to little byte order conversion or vice versa. Leaving those sparse issues ignored and always do it in out/in functionality tends to leave it unknown in which byte order the variable is being handled. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: use __le types for options headerAlexander Aring1-5/+5
This patch changes to use __le types directly in the dlm option headers structures which are casted at the right dlm message buffer positions. Currently only midcomms.c using those headers which already was calling endian conversions on-the-fly without using in/out functionality like other endianness handling in dlm. Using __le types now will hopefully get useful warnings in future if we do comparison against host byte order values. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: add __CHECKER__ for false positivesAlexander Aring2-0/+20
This patch will adds #ifndef __CHECKER__ for false positives warnings about an imbalance lock/unlock srcu handling. Which are shown by running sparse checks: fs/dlm/midcomms.c:1065:20: warning: context imbalance in 'dlm_midcomms_get_mhandle' - wrong count at exit Using __CHECKER__ will tell sparse to ignore these sections. Those imbalances are false positive because from upper layer it is always required to call a function in sequence, e.g. if dlm_midcomms_get_mhandle() is successful there must be a dlm_midcomms_commit_mhandle() call afterwards. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: move global to static initsAlexander Aring1-11/+5
Instead of init global module at module loading time we can move the initialization of those global variables at memory initialization of the module loader. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: remove unnecessary INIT_LIST_HEAD()Alexander Aring1-1/+0
There is no need to call INIT_LIST_HEAD() when it's set directly afterwards by list_add_tail(). Reported-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: improve plock logging if interruptedAlexander Aring1-4/+5
This patch changes the log level if a plock is removed when interrupted from debug to info. Additional it signals now that the plock entity was removed to let the user know what's happening. If on a dev_write() a pending plock cannot be find it will signal that it might have been removed because wait interruption. Before this patch there might be a "dev_write no op ..." info message and the users can only guess that the plock was removed before because the wait interruption. To be sure that is the case we log both messages on the same log level. Let both message be logged on info layer because it should not happened a lot and if it happens it should be clear why the op was not found. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: rearrange async condition returnAlexander Aring1-14/+13
This patch moves the return of FILE_LOCK_DEFERRED a little bit earlier than checking afterwards again if the request was an asynchronous request. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: cleanup plock_op vs plock_xopAlexander Aring1-31/+46
Lately the different casting between plock_op and plock_xop and list holders which was involved showed some issues which were hard to see. This patch removes the "plock_xop" structure and introduces a "struct plock_async_data". This structure will be set in "struct plock_op" in case of asynchronous lock handling as the original "plock_xop" was made for. There is no need anymore to cast pointers around for additional fields in case of asynchronous lock handling. As disadvantage another allocation was introduces but only needed in the asynchronous case which is currently only used in combination with nfs lockd. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: replace sanity checks with WARN_ONAlexander Aring1-28/+4
There are several sanity checks and recover handling if they occur in the dlm plock handling. From my understanding those operation can't run in parallel with any list manipulation which involved setting the list holder of plock_op, if so we have a bug which this sanity check will warn about. Previously if such sanity check occurred the dlm plock handling was trying to recover from it by deleting the plock_op from a list which the holder was set to. However there is a bug in the dlm plock handling if this case ever happens. To make such bugs are more visible for further investigations we add a WARN_ON() on those sanity checks and remove the recovering handling because other possible side effects. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: fix plock invalid readAlexander Aring1-7/+5
This patch fixes an invalid read showed by KASAN. A unlock will allocate a "struct plock_op" and a followed send_op() will append it to a global send_list data structure. In some cases a followed dev_read() moves it to recv_list and dev_write() will cast it to "struct plock_xop" and access fields which are only available in those structures. At this point an invalid read happens by accessing those fields. To fix this issue the "callback" field is moved to "struct plock_op" to indicate that a cast to "plock_xop" is allowed and does the additional "plock_xop" handling if set. Example of the KASAN output which showed the invalid read: [ 2064.296453] ================================================================== [ 2064.304852] BUG: KASAN: slab-out-of-bounds in dev_write+0x52b/0x5a0 [dlm] [ 2064.306491] Read of size 8 at addr ffff88800ef227d8 by task dlm_controld/7484 [ 2064.308168] [ 2064.308575] CPU: 0 PID: 7484 Comm: dlm_controld Kdump: loaded Not tainted 5.14.0+ #9 [ 2064.310292] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 [ 2064.311618] Call Trace: [ 2064.312218] dump_stack_lvl+0x56/0x7b [ 2064.313150] print_address_description.constprop.8+0x21/0x150 [ 2064.314578] ? dev_write+0x52b/0x5a0 [dlm] [ 2064.315610] ? dev_write+0x52b/0x5a0 [dlm] [ 2064.316595] kasan_report.cold.14+0x7f/0x11b [ 2064.317674] ? dev_write+0x52b/0x5a0 [dlm] [ 2064.318687] dev_write+0x52b/0x5a0 [dlm] [ 2064.319629] ? dev_read+0x4a0/0x4a0 [dlm] [ 2064.320713] ? bpf_lsm_kernfs_init_security+0x10/0x10 [ 2064.321926] vfs_write+0x17e/0x930 [ 2064.322769] ? __fget_light+0x1aa/0x220 [ 2064.323753] ksys_write+0xf1/0x1c0 [ 2064.324548] ? __ia32_sys_read+0xb0/0xb0 [ 2064.325464] do_syscall_64+0x3a/0x80 [ 2064.326387] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 2064.327606] RIP: 0033:0x7f807e4ba96f [ 2064.328470] Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 39 87 f8 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 7c 87 f8 ff 48 [ 2064.332902] RSP: 002b:00007ffd50cfe6e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 [ 2064.334658] RAX: ffffffffffffffda RBX: 000055cc3886eb30 RCX: 00007f807e4ba96f [ 2064.336275] RDX: 0000000000000040 RSI: 00007ffd50cfe7e0 RDI: 0000000000000010 [ 2064.337980] RBP: 00007ffd50cfe7e0 R08: 0000000000000000 R09: 0000000000000001 [ 2064.339560] R10: 000055cc3886eb30 R11: 0000000000000293 R12: 000055cc3886eb80 [ 2064.341237] R13: 000055cc3886eb00 R14: 000055cc3886f590 R15: 0000000000000001 [ 2064.342857] [ 2064.343226] Allocated by task 12438: [ 2064.344057] kasan_save_stack+0x1c/0x40 [ 2064.345079] __kasan_kmalloc+0x84/0xa0 [ 2064.345933] kmem_cache_alloc_trace+0x13b/0x220 [ 2064.346953] dlm_posix_unlock+0xec/0x720 [dlm] [ 2064.348811] do_lock_file_wait.part.32+0xca/0x1d0 [ 2064.351070] fcntl_setlk+0x281/0xbc0 [ 2064.352879] do_fcntl+0x5e4/0xfe0 [ 2064.354657] __x64_sys_fcntl+0x11f/0x170 [ 2064.356550] do_syscall_64+0x3a/0x80 [ 2064.358259] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 2064.360745] [ 2064.361511] Last potentially related work creation: [ 2064.363957] kasan_save_stack+0x1c/0x40 [ 2064.365811] __kasan_record_aux_stack+0xaf/0xc0 [ 2064.368100] call_rcu+0x11b/0xf70 [ 2064.369785] dlm_process_incoming_buffer+0x47d/0xfd0 [dlm] [ 2064.372404] receive_from_sock+0x290/0x770 [dlm] [ 2064.374607] process_recv_sockets+0x32/0x40 [dlm] [ 2064.377290] process_one_work+0x9a8/0x16e0 [ 2064.379357] worker_thread+0x87/0xbf0 [ 2064.381188] kthread+0x3ac/0x490 [ 2064.383460] ret_from_fork+0x22/0x30 [ 2064.385588] [ 2064.386518] Second to last potentially related work creation: [ 2064.389219] kasan_save_stack+0x1c/0x40 [ 2064.391043] __kasan_record_aux_stack+0xaf/0xc0 [ 2064.393303] call_rcu+0x11b/0xf70 [ 2064.394885] dlm_process_incoming_buffer+0x47d/0xfd0 [dlm] [ 2064.397694] receive_from_sock+0x290/0x770 [dlm] [ 2064.399932] process_recv_sockets+0x32/0x40 [dlm] [ 2064.402180] process_one_work+0x9a8/0x16e0 [ 2064.404388] worker_thread+0x87/0xbf0 [ 2064.406124] kthread+0x3ac/0x490 [ 2064.408021] ret_from_fork+0x22/0x30 [ 2064.409834] [ 2064.410599] The buggy address belongs to the object at ffff88800ef22780 [ 2064.410599] which belongs to the cache kmalloc-96 of size 96 [ 2064.416495] The buggy address is located 88 bytes inside of [ 2064.416495] 96-byte region [ffff88800ef22780, ffff88800ef227e0) [ 2064.422045] The buggy address belongs to the page: [ 2064.424635] page:00000000b6bef8bc refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xef22 [ 2064.428970] flags: 0xfffffc0000200(slab|node=0|zone=1|lastcpupid=0x1fffff) [ 2064.432515] raw: 000fffffc0000200 ffffea0000d68b80 0000001400000014 ffff888001041780 [ 2064.436110] raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000 [ 2064.439813] page dumped because: kasan: bad access detected [ 2064.442548] [ 2064.443310] Memory state around the buggy address: [ 2064.445988] ffff88800ef22680: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 2064.449444] ffff88800ef22700: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 2064.452941] >ffff88800ef22780: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc [ 2064.456383] ^ [ 2064.459386] ffff88800ef22800: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc [ 2064.462788] ffff88800ef22880: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 2064.466239] ================================================================== reproducer in python: import argparse import struct import fcntl import os parser = argparse.ArgumentParser() parser.add_argument('-f', '--file', help='file to use fcntl, must be on dlm lock filesystem e.g. gfs2') args = parser.parse_args() f = open(args.file, 'wb+') lockdata = struct.pack('hhllhh', fcntl.F_WRLCK,0,0,0,0,0) fcntl.fcntl(f, fcntl.F_SETLK, lockdata) lockdata = struct.pack('hhllhh', fcntl.F_UNLCK,0,0,0,0,0) fcntl.fcntl(f, fcntl.F_SETLK, lockdata) Fixes: 586759f03e2e ("gfs2: nfs lock support for gfs2") Cc: stable@vger.kernel.org Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: fix missing check in validate_lock_argsAlexander Aring1-1/+2
This patch adds a additional check if lkb->lkb_wait_count is non zero as it is done in validate_unlock_args() to check if any operation is in progress. While on it add a comment taken from validate_unlock_args() to signal what the check is doing. There might be no changes because if lkb->lkb_wait_type is non zero implies that lkb->lkb_wait_count is non zero. However we should add the check as it does validate_unlock_args(). Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-04-06dlm: uninitialized variable on error in dlm_listen_for_all()Dan Carpenter1-1/+1
The "sock" variable is not initialized on this error path. Cc: stable@vger.kernel.org Fixes: 2dc6b1158c28 ("fs: dlm: introduce generic listen") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2022-01-12Merge tag 'driver-core-5.17-rc1' of ↵Linus Torvalds1-2/+1
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the set of changes for the driver core for 5.17-rc1. Lots of little things here, including: - kobj_type cleanups - auxiliary_bus documentation updates - auxiliary_device conversions for some drivers (relevant subsystems all have provided acks for these) - kernfs lock contention reduction for some workloads - other tiny cleanups and changes. All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (43 commits) kobject documentation: remove default_attrs information drivers/firmware: Add missing platform_device_put() in sysfb_create_simplefb debugfs: lockdown: Allow reading debugfs files that are not world readable driver core: Make bus notifiers in right order in really_probe() driver core: Move driver_sysfs_remove() after driver_sysfs_add() firmware: edd: remove empty default_attrs array firmware: dmi-sysfs: use default_groups in kobj_type qemu_fw_cfg: use default_groups in kobj_type firmware: memmap: use default_groups in kobj_type sh: sq: use default_groups in kobj_type headers/uninline: Uninline single-use function: kobject_has_children() devtmpfs: mount with noexec and nosuid driver core: Simplify async probe test code by using ktime_ms_delta() nilfs2: use default_groups in kobj_type kobject: remove kset from struct kset_uevent_ops callbacks driver core: make kobj_type constant. driver core: platform: document registration-failure requirement vdpa/mlx5: Use auxiliary_device driver data helpers net/mlx5e: Use auxiliary_device driver data helpers soundwire: intel: Use auxiliary_device driver data helpers ...
2022-01-04fs: dlm: print cluster addr if non-cluster node connectsAlexander Aring1-4/+22
This patch prints the cluster node address if a non-cluster node (according to the dlm config setting) tries to connect. The current hexdump call will print in a different loglevel and only available if dynamic debug is enabled. Additional we using the ip address format strings to print an IETF ip4/6 string represenation. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-12-28kobject: remove kset from struct kset_uevent_ops callbacksGreg Kroah-Hartman1-2/+1
There is no need to pass the pointer to the kset in the struct kset_uevent_ops callbacks as no one uses it, so just remove that pointer entirely. Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Wedson Almeida Filho <wedsonaf@google.com> Link: https://lore.kernel.org/r/20211227163924.3970661-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-07fs: dlm: memory cache for lowcomms hotpathAlexander Aring4-3/+31
This patch introduces a kmem cache for dlm_msg handles which are used always if dlm sends a message out. Even if their are covered by midcomms layer or not. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-12-07fs: dlm: memory cache for writequeue_entryAlexander Aring4-6/+44
This patch introduces a kmem cache for writequeue entry. A writequeue entry get quite a lot allocated if dlm transmit messages. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-12-07fs: dlm: memory cache for midcomms hotpathAlexander Aring4-11/+44
This patch will introduce a kmem cache for allocating message handles which are needed for midcomms layer to take track of lowcomms messages. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-12-07fs: dlm: remove wq_alloc mutexAlexander Aring1-37/+11
This patch cleanups the code for allocating a new buffer in the dlm writequeue mechanism. There was a possible tuneup to allow scheduling while a new writequeue entry needs to be allocated because either no sending page is available or are full. To avoid multiple concurrent users checking at the same time if an entry is available or full alloc_wq was introduce that those are waiting if there is currently a new writequeue entry in process to be queued so possible further users will check on the new allocated writequeue entry if it's full. To simplify the code we just remove this mutex and switch that the already introduced spin lock will be held during writequeue check, allocation and queueing. So other users can never check on available writequeues while there is a new one in process but not queued yet. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-12-07fs: dlm: use event based wait for pending removeAlexander Aring3-7/+14
This patch will use an event based waitqueue to wait for a possible clash with the ls_remove_name field of dlm_ls instead of doing busy waiting. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-12-07fs: dlm: check for pending users filling buffersAlexander Aring1-1/+4
Currently we don't care if the DLM application stack is filling buffers (not committed yet) while we transmit some already committed buffers. By checking on active writequeue users before dequeue a writequeue entry we know there is coming more data and do nothing. We wait until the send worker will be triggered again if the writequeue entry users hit zero. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-12-07fs: dlm: use list_empty() to check last iterationAlexander Aring1-1/+3
This patch will use list_empty(&ls->ls_cb_delay) to check for last list iteration. In case of a multiply count of MAX_CB_QUEUE and the list is empty we do a extra goto more which we can avoid by checking on list_empty(). Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-17fs: dlm: fix build with CONFIG_IPV6 disabledAlexander Aring1-0/+2
This patch will surround the AF_INET6 case in sk_error_report() of dlm with a #if IS_ENABLED(CONFIG_IPV6). The field sk->sk_v6_daddr is not defined when CONFIG_IPV6 is disabled. If CONFIG_IPV6 is disabled, the socket creation with AF_INET6 should already fail because a runtime check if AF_INET6 is registered. However if there is the possibility that AF_INET6 is set as sk_family the sk_error_report() callback will print then an invalid family type error. Reported-by: kernel test robot <lkp@intel.com> Fixes: 4c3d90570bcc ("fs: dlm: don't call kernel_getpeername() in error_report()") Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-15fs: dlm: replace use of socket sk_callback_lock with sock_lockAlexander Aring1-17/+10
This patch will replace the use of socket sk_callback_lock lock and uses socket lock instead. Some users like sunrpc, see commit ea9afca88bbe ("SUNRPC: Replace use of socket sk_callback_lock with sock_lock") moving from sk_callback_lock to sock_lock which seems to be held when the socket callbacks are called. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-15fs: dlm: don't call kernel_getpeername() in error_report()Alexander Aring1-22/+20
In some cases kernel_getpeername() will held the socket lock which is already held when the socket layer calls error_report() callback. Since commit 9dfc685e0262 ("inet: remove races in inet{6}_getname()") this problem becomes more likely because the socket lock will be held always. You will see something like: bob9-u5 login: [ 562.316860] BUG: spinlock recursion on CPU#7, swapper/7/0 [ 562.318562] lock: 0xffff8f2284720088, .magic: dead4ead, .owner: swapper/7/0, .owner_cpu: 7 [ 562.319522] CPU: 7 PID: 0 Comm: swapper/7 Not tainted 5.15.0+ #135 [ 562.320346] Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.13.0-2.module+el8.3.0+7353+9de0a3cc 04/01/2014 [ 562.321277] Call Trace: [ 562.321529] <IRQ> [ 562.321734] dump_stack_lvl+0x33/0x42 [ 562.322282] do_raw_spin_lock+0x8b/0xc0 [ 562.322674] lock_sock_nested+0x1e/0x50 [ 562.323057] inet_getname+0x39/0x110 [ 562.323425] ? sock_def_readable+0x80/0x80 [ 562.323838] lowcomms_error_report+0x63/0x260 [dlm] [ 562.324338] ? wait_for_completion_interruptible_timeout+0xd2/0x120 [ 562.324949] ? lock_timer_base+0x67/0x80 [ 562.325330] ? do_raw_spin_unlock+0x49/0xc0 [ 562.325735] ? _raw_spin_unlock_irqrestore+0x1e/0x40 [ 562.326218] ? del_timer+0x54/0x80 [ 562.326549] sk_error_report+0x12/0x70 [ 562.326919] tcp_validate_incoming+0x3c8/0x530 [ 562.327347] ? kvm_clock_read+0x14/0x30 [ 562.327718] ? ktime_get+0x3b/0xa0 [ 562.328055] tcp_rcv_established+0x121/0x660 [ 562.328466] tcp_v4_do_rcv+0x132/0x260 [ 562.328835] tcp_v4_rcv+0xcea/0xe20 [ 562.329173] ip_protocol_deliver_rcu+0x35/0x1f0 [ 562.329615] ip_local_deliver_finish+0x54/0x60 [ 562.330050] ip_local_deliver+0xf7/0x110 [ 562.330431] ? inet_rtm_getroute+0x211/0x840 [ 562.330848] ? ip_protocol_deliver_rcu+0x1f0/0x1f0 [ 562.331310] ip_rcv+0xe1/0xf0 [ 562.331603] ? ip_local_deliver+0x110/0x110 [ 562.332011] __netif_receive_skb_core+0x46a/0x1040 [ 562.332476] ? inet_gro_receive+0x263/0x2e0 [ 562.332885] __netif_receive_skb_list_core+0x13b/0x2c0 [ 562.333383] netif_receive_skb_list_internal+0x1c8/0x2f0 [ 562.333896] ? update_load_avg+0x7e/0x5e0 [ 562.334285] gro_normal_list.part.149+0x19/0x40 [ 562.334722] napi_complete_done+0x67/0x160 [ 562.335134] virtnet_poll+0x2ad/0x408 [virtio_net] [ 562.335644] __napi_poll+0x28/0x140 [ 562.336012] net_rx_action+0x23d/0x300 [ 562.336414] __do_softirq+0xf2/0x2ea [ 562.336803] irq_exit_rcu+0xc1/0xf0 [ 562.337173] common_interrupt+0xb9/0xd0 It is and was always forbidden to call kernel_getpeername() in context of error_report(). To get rid of the problem we access the destination address for the peer over the socket structure. While on it we fix to print out the destination port of the inet socket. Fixes: 1a31833d085a ("DLM: Replace nodeid_to_addr with kernel_getpeername") Reported-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-12fs: dlm: fix potential buffer overflowAlexander Aring1-1/+1
This patch fixes an potential overflow in sscanf and the maximum declared string parsing length which seems to be excluding the null termination symbol. This patch will just add one byte to be prepared on a string with length of DLM_RESNAME_MAXLEN including the null termination symbol. Fixes: 5054e79de999 ("fs: dlm: add lkb debugfs functionality") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-05fs: dlm:Remove unneeded semicolonZhang Mingyu1-1/+1
Eliminate the following coccinelle check warning: fs/dlm/midcomms.c:972:2-3 Reported-by: Zeal Robot <zealci@zte.com.cn> Signed-off-by: Zhang Mingyu <zhang.mingyu@zte.com.cn> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-04fs: dlm: remove double list_first_entry callAlexander Aring1-1/+0
This patch removes a list_first_entry() call which is already done by the previous con_next_wq() call. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-02fs: dlm: filter user dlm messages for kernel locksAlexander Aring1-0/+9
This patch fixes the following crash by receiving a invalid message: [ 160.672220] ================================================================== [ 160.676206] BUG: KASAN: user-memory-access in dlm_user_add_ast+0xc3/0x370 [ 160.679659] Read of size 8 at addr 00000000deadbeef by task kworker/u32:13/319 [ 160.681447] [ 160.681824] CPU: 10 PID: 319 Comm: kworker/u32:13 Not tainted 5.14.0-rc2+ #399 [ 160.683472] Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.14.0-1.module+el8.6.0+12648+6ede71a5 04/01/2014 [ 160.685574] Workqueue: dlm_recv process_recv_sockets [ 160.686721] Call Trace: [ 160.687310] dump_stack_lvl+0x56/0x6f [ 160.688169] ? dlm_user_add_ast+0xc3/0x370 [ 160.689116] kasan_report.cold.14+0x116/0x11b [ 160.690138] ? dlm_user_add_ast+0xc3/0x370 [ 160.690832] dlm_user_add_ast+0xc3/0x370 [ 160.691502] _receive_unlock_reply+0x103/0x170 [ 160.692241] _receive_message+0x11df/0x1ec0 [ 160.692926] ? rcu_read_lock_sched_held+0xa1/0xd0 [ 160.693700] ? rcu_read_lock_bh_held+0xb0/0xb0 [ 160.694427] ? lock_acquire+0x175/0x400 [ 160.695058] ? do_purge.isra.51+0x200/0x200 [ 160.695744] ? lock_acquired+0x360/0x5d0 [ 160.696400] ? lock_contended+0x6a0/0x6a0 [ 160.697055] ? lock_release+0x21d/0x5e0 [ 160.697686] ? lock_is_held_type+0xe0/0x110 [ 160.698352] ? lock_is_held_type+0xe0/0x110 [ 160.699026] ? ___might_sleep+0x1cc/0x1e0 [ 160.699698] ? dlm_wait_requestqueue+0x94/0x140 [ 160.700451] ? dlm_process_requestqueue+0x240/0x240 [ 160.701249] ? down_write_killable+0x2b0/0x2b0 [ 160.701988] ? do_raw_spin_unlock+0xa2/0x130 [ 160.702690] dlm_receive_buffer+0x1a5/0x210 [ 160.703385] dlm_process_incoming_buffer+0x726/0x9f0 [ 160.704210] receive_from_sock+0x1c0/0x3b0 [ 160.704886] ? dlm_tcp_shutdown+0x30/0x30 [ 160.705561] ? lock_acquire+0x175/0x400 [ 160.706197] ? rcu_read_lock_sched_held+0xa1/0xd0 [ 160.706941] ? rcu_read_lock_bh_held+0xb0/0xb0 [ 160.707681] process_recv_sockets+0x32/0x40 [ 160.708366] process_one_work+0x55e/0xad0 [ 160.709045] ? pwq_dec_nr_in_flight+0x110/0x110 [ 160.709820] worker_thread+0x65/0x5e0 [ 160.710423] ? process_one_work+0xad0/0xad0 [ 160.711087] kthread+0x1ed/0x220 [ 160.711628] ? set_kthread_struct+0x80/0x80 [ 160.712314] ret_from_fork+0x22/0x30 The issue is that we received a DLM message for a user lock but the destination lock is a kernel lock. Note that the address which is trying to derefence is 00000000deadbeef, which is in a kernel lock lkb->lkb_astparam, this field should never be derefenced by the DLM kernel stack. In case of a user lock lkb->lkb_astparam is lkb->lkb_ua (memory is shared by a union field). The struct lkb_ua will be handled by the DLM kernel stack but on a kernel lock it will contain invalid data and ends in most likely crashing the kernel. It can be reproduced with two cluster nodes. node 2: dlm_tool join test echo "862 fooobaar 1 2 1" > /sys/kernel/debug/dlm/test_locks echo "862 3 1" > /sys/kernel/debug/dlm/test_waiters node 1: dlm_tool join test python: foo = DLM(h_cmd=3, o_nextcmd=1, h_nodeid=1, h_lockspace=0x77222027, \ m_type=7, m_flags=0x1, m_remid=0x862, m_result=0xFFFEFFFE) newFile = open("/sys/kernel/debug/dlm/comms/2/rawmsg", "wb") newFile.write(bytes(foo)) Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-02fs: dlm: add lkb waiters debugfs functionalityAlexander Aring3-1/+43
This patch adds functionality to put a lkb to the waiters state. It can be useful to combine this feature with the "rawmsg" debugfs functionality. It will bring the DLM lkb into a state that a message will be parsed by the kernel. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-02fs: dlm: add lkb debugfs functionalityAlexander Aring3-1/+79
This patch adds functionality to add an lkb during runtime. This is a highly debugging feature only, wrong input can crash the kernel. It is a early state feature as well. The goal is to provide a user interface for manipulate dlm state and combine it with the rawmsg feature. It is debugfs functionality, we don't care about UAPI breakage. Even it's possible to add lkb's/rsb's which could never be exists in such wat by using normal DLM operation. The user of this interface always need to think before using this feature, not every crash which happens can really occur during normal dlm operation. Future there should be more functionality to add a more realistic lkb which reflects normal DLM state inside the kernel. For now this is enough. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-02fs: dlm: allow create lkb with specific id rangeAlexander Aring1-2/+8
This patch adds functionality to add a lkb with a specific id range. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-02fs: dlm: add debugfs rawmsg send functionalityAlexander Aring3-0/+87
This patch adds a dlm functionality to send a raw dlm message to a specific cluster node. This raw message can be build by user space and send out by writing the message to "rawmsg" dlm debugfs file. There is a in progress scapy dlm module which provides a easy build of DLM messages in user space. For example: DLM(h_cmd=3, o_nextcmd=1, h_nodeid=1, h_lockspace=0xe4f48a18, ...) The goal is to provide an easy reproducable state to crash DLM or to fuzz the DLM kernel stack if there are possible ways to crash it. Note: that if the sequence number is zero and dlm version is not set to 3.1 the kernel will automatic will set a right sequence number, otherwise DLM stack testing is not possible. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2021-11-02fs: dlm: let handle callback data as voidAlexander Aring3-13/+14
This patch changes the dlm_lowcomms_new_msg() function pointer private data from "struct mhandle *" to "void *" to provide different structures than just "struct mhandle". Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>