linux/fs/dlm, branch v6.7

dlm: slow down filling up processing queue

2023-10-12T20:21:00Z

If there is a burst of message the receive worker will filling up the processing queue but where are too slow to process dlm messages. This patch will slow down the receiver worker to keep the buffer on the socket layer to tell the sender to backoff. This is done by a threshold to get the next buffers from the socket after all messages were processed done by a flush_workqueue(). This however only occurs when we have a message burst when we e.g. create 1 million locks. If we put more and more new messages to process in the processqueue we will soon run out of memory. Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: fix no ack after final message

2023-10-12T20:20:55Z

In case of an final DLM message we can't should not send an ack out after the final message. This patch moves the ack message before the messages will be transmitted. If it's the final message and the receiving node turns into DLM_CLOSED state another ack messages will being received and turning the receiving node into DLM_ESTABLISHED again. Fixes: 1696c75f1864 ("fs: dlm: add send ack threshold and append acks to msgs") Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: be sure we reset all nodes at forced shutdown

2023-10-12T20:20:48Z

In case we running in a force shutdown in either midcomms or lowcomms implementation we will make sure we reset all per midcomms node information. Fixes: 63e711b08160 ("fs: dlm: create midcomms nodes when configure") Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: fix remove member after close call

2023-10-12T20:20:37Z

The idea of commit 63e711b08160 ("fs: dlm: create midcomms nodes when configure") is to set the midcomms node lifetime when a node joins or leaves the cluster. Currently we can hit the following warning: [10844.611495] ------------[ cut here ]------------ [10844.615913] WARNING: CPU: 4 PID: 84304 at fs/dlm/midcomms.c:1263 dlm_midcomms_remove_member+0x13f/0x180 [dlm] or running in a state where we hit a midcomms node usage count in a negative value: [ 260.830782] node 2 users dec count -1 The first warning happens when the a specific node does not exists and it was probably removed but dlm_midcomms_close() which is called when a node leaves the cluster. The second kernel log message is probably in a case when dlm_midcomms_addr() is called when a joined the cluster but due fencing a node leaved the cluster without getting removed from the lockspace. If the node joins the cluster and it was removed from the cluster due fencing the first call is to remove the node from lockspaces triggered by the user space. In both cases if the node wasn't found or the user count is zero, we should ignore any additional midcomms handling of dlm_midcomms_remove_member(). Fixes: 63e711b08160 ("fs: dlm: create midcomms nodes when configure") Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: fix creating multiple node structures

2023-10-12T20:20:28Z

This patch will lookup existing nodes instead of always creating them when dlm_midcomms_addr() is called. The idea is here to create midcomms nodes when user space getting informed that nodes joins the cluster. This is the case when dlm_midcomms_addr() is called, however it can be called multiple times by user space to add several address configurations to one node e.g. when using SCTP. Those multiple times need to be filtered out and we doing that by looking up if the node exists before. Due configfs entry it is safe that this function gets only called once at a time. Fixes: 63e711b08160 ("fs: dlm: create midcomms nodes when configure") Signed-off-by: Alexander Aring Signed-off-by: David Teigland

fs: dlm: Remove some useless memset()

2023-10-12T20:20:17Z

There is no need to clear the buffer used to build the file name. snprintf() already guarantees that it is NULL terminated and such a (useless) precaution was not done for the first string (i.e ls_debug_rsb_dentry) So, save a few LoC. Signed-off-by: Christophe JAILLET Signed-off-by: Alexander Aring Signed-off-by: David Teigland

fs: dlm: Fix the size of a buffer in dlm_create_debug_file()

2023-10-12T20:19:37Z

8 is not the maximum size of the suffix used when creating debugfs files. Let the compiler compute the correct size, and only give a hint about the longest possible string that is used. When building with W=1, this fixes the following warnings: fs/dlm/debug_fs.c: In function ‘dlm_create_debug_file’: fs/dlm/debug_fs.c:1020:58: error: ‘snprintf’ output may be truncated before the last format character [-Werror=format-truncation=] 1020 | snprintf(name, DLM_LOCKSPACE_LEN + 8, "%s_waiters", ls->ls_name); | ^ fs/dlm/debug_fs.c:1020:9: note: ‘snprintf’ output between 9 and 73 bytes into a destination of size 72 1020 | snprintf(name, DLM_LOCKSPACE_LEN + 8, "%s_waiters", ls->ls_name); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/dlm/debug_fs.c:1031:50: error: ‘_queued_asts’ directive output may be truncated writing 12 bytes into a region of size between 8 and 72 [-Werror=format-truncation=] 1031 | snprintf(name, DLM_LOCKSPACE_LEN + 8, "%s_queued_asts", ls->ls_name); | ^~~~~~~~~~~~ fs/dlm/debug_fs.c:1031:9: note: ‘snprintf’ output between 13 and 77 bytes into a destination of size 72 1031 | snprintf(name, DLM_LOCKSPACE_LEN + 8, "%s_queued_asts", ls->ls_name); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Fixes: 541adb0d4d10b ("fs: dlm: debugfs for queued callbacks") Signed-off-by: Christophe JAILLET Signed-off-by: Alexander Aring Signed-off-by: David Teigland

fs: dlm: Simplify buffer size computation in dlm_create_debug_file()

2023-10-12T20:19:29Z

Use sizeof(name) instead of the equivalent, but hard coded, DLM_LOCKSPACE_LEN + 8. This is less verbose and more future proof. Signed-off-by: Christophe JAILLET Signed-off-by: Alexander Aring Signed-off-by: David Teigland

dlm: fix plock lookup when using multiple lockspaces

2023-08-25T15:31:39Z

All posix lock ops, for all lockspaces (gfs2 file systems) are sent to userspace (dlm_controld) through a single misc device. The dlm_controld daemon reads the ops from the misc device and sends them to other cluster nodes using separate, per-lockspace cluster api communication channels. The ops for a single lockspace are ordered at this level, so that the results are received in the same sequence that the requests were sent. When the results are sent back to the kernel via the misc device, they are again funneled through the single misc device for all lockspaces. When the dlm code in the kernel processes the results from the misc device, these results will be returned in the same sequence that the requests were sent, on a per-lockspace basis. A recent change in this request/reply matching code missed the "per-lockspace" check (fsid comparison) when matching request and reply, so replies could be incorrectly matched to requests from other lockspaces. Cc: stable@vger.kernel.org Reported-by: Barry Marson Fixes: 57e2c2f2d94c ("fs: dlm: fix mismatch of plock results from userspace") Signed-off-by: Alexander Aring Signed-off-by: David Teigland

fs: dlm: don't use RCOM_NAMES for version detection

2023-08-10T15:33:03Z

Currently RCOM_STATUS and RCOM_NAMES inclusive their replies are being used to determine the DLM version. The RCOM_NAMES messages are triggered in DLM recovery when calling dlm_recover_directory() only. At this time the DLM version need to be determined. I ran some tests and did not expirenced some issues. When the DLM version detection was developed probably I run once in a case of RCOM_NAMES and the version was not detected yet. However it seems to be not necessary. For backwards compatibility we still need to accept RCOM_NAMES messages which are not protected regarding the DLM message reliability layer aka stateless message. This patch changes that RCOM_NAMES we are sending out after this patch are not stateless anymore. Signed-off-by: Alexander Aring Signed-off-by: David Teigland