kernel/linux.git/fs/dlm/user.c, branch v6.12.80

dlm: implement LSFL_SOFTIRQ_SAFE

2024-06-11T18:13:00+00:00

When a lockspace user allows it, run callback functions directly from softirq context, instead of queueing callbacks to be run from the dlm_callback workqueue context. Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: remove ls_local_handle from struct dlm_ls

2024-05-31T16:04:54+00:00

This patch removes ls_local_handle from struct dlm_ls as it stores the ls pointer of the top level structure itesef and this isn't necessary. There is a lookup functionality to lookup the lockspace in dlm_find_lockspace_local() but the given input parameter is the pointer already. This might be more safe to lookup a lockspace but given a wrong lockspace pointer is a bug in the code and we save the additional lookup here. The dlm_ls structure can be still hidden by using dlm_lockspace_t handle pointer. Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: use spin_lock_bh for message processing

2024-04-09T16:45:23+00:00

Use spin_lock_bh for all spinlocks involved in message processing, in preparation for softirq message processing. DLM lock requests from user space involve dlm processing in user context, in addition to the standard kernel context, necessitating bh variants. Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: remove callback reference counting

2024-04-01T18:31:13+00:00

Get rid of the unnecessary refcounting on callback structs. Copy interesting callback info into the lkb struct rather than maintaining pointers to callback structs from the lkb. This goes back to the way things were done prior to commit 61bed0baa4db ("fs: dlm: use a non-static queue for callbacks"). Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: fix race between final callback and remove

2024-04-01T18:31:12+00:00

This patch fixes the following issue: node 1 is dir node 2 is master node 3 is other 1->2: unlock 2: put final lkb, rsb moved to toss 2->1: unlock_reply 1: queue lkb callback with EUNLOCK 2->1: remove 1: receive_remove ignored (rsb on keep because of queued lkb callback) 1: complete lkb callback, put_lkb, move rsb to toss 3->1: lookup 1->3: lookup_reply master=2 3->2: request 2->3: request_reply EBADR In summary: An unexpected lkb reference causes the rsb to remain on the wrong list. The rsb being on the wrong list causes receive_remove to be ignored. An ignored receive_remove causes inconsistent dir and master state. This sequence requires an unusually long delay in delivering the unlock callback, because the remove message from 2->1 usually happens after some seconds. So, it's not known exactly how frequently this sequence occurs in pratice. It's possible that the same end result could also have another unknown cause. The solution for this issue is to further separate callback state from the lkb, so that an lkb reference (and from that, an rsb ref) are not held while a callback remains queued. Then, within the unlock_reply, the lkb will be freed and the rsb moved to the toss list. So, the receive_remove will not be ignored. Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: combine switch case fail and default statements

2024-04-01T18:31:12+00:00

This patch combines the failure and default cases for enqueue and dequeue a callback to the lkb callback queue that should end in both cases as it should never happen. Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: remove lkb from callback tracepoints

2024-04-01T18:31:12+00:00

Stop using lkb structs in the callback tracepoints so that lkb references are not needed. This prepares for separating lkb structs from callbacks. Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: fix user space lock decision to copy lvb

2024-04-01T18:31:12+00:00

This patch fixes the copy lvb decision for user space lock requests. Checking dlm_lvb_operations is done earlier, where granted/requested lock modes are available to use in the matrix. The decision had been moved to the wrong location, where granted mode and requested mode where the same, which causes the dlm_lvb_operations matix to produce the wrong copy decision. For PW or EX requests, the caller could get invalid lvb data. Fixes: 61bed0baa4db ("fs: dlm: use a non-static queue for callbacks") Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: fix user space lkb refcounting

2024-03-12T17:12:52+00:00

This patch fixes to check on the right return value if it was the last callback. The rv variable got overwritten by the return of copy_result_to_user(). Fixing it by introducing a second variable for the return value and don't let rv being overwritten. Cc: stable@vger.kernel.org Fixes: 61bed0baa4db ("fs: dlm: use a non-static queue for callbacks") Reported-by: Valentin Vidić Closes: https://lore.kernel.org/gfs2/Ze4qSvzGJDt5yxC3@valentin-vidic.from.hr Signed-off-by: Alexander Aring Signed-off-by: David Teigland

fs: dlm: move dlm_purge_lkb_callbacks to user module

2023-06-14T15:17:33+00:00

This patch moves the dlm_purge_lkb_callbacks() function from ast to user dlm module as it is only a function being used by dlm user implementation. I got be hinted to hold specific locks regarding the callback handling for dlm_purge_lkb_callbacks() but it was false positive. It is confusing because ast dlm implementation uses a different locking behaviour as user locks uses as DLM handles kernel and user dlm locks differently. To avoid the confusing we move this function to dlm user implementation. Signed-off-by: Alexander Aring Signed-off-by: David Teigland