From 8b4021fa436f7c76a2299e6d85d4d4a619724e9a Mon Sep 17 00:00:00 2001 From: David Teigland Date: Tue, 29 May 2007 08:46:00 -0500 Subject: [PATCH] [DLM] canceling deadlocked lock Add a function that can be used through libdlm by a system daemon to cancel another process's deadlocked lock. A completion ast with EDEADLK is returned to the process waiting for the lock. Signed-off-by: David Teigland Signed-off-by: Steven Whitehouse --- fs/dlm/dlm_internal.h | 1 + fs/dlm/lock.c | 53 ++++++++++++++++++++++++++++++++++++++ fs/dlm/lock.h | 1 + fs/dlm/user.c | 25 ++++++++++++++++++ include/linux/dlm_device.h | 1 + 5 files changed, 81 insertions(+) diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h index a7435a8df35e..a006fa59e7da 100644 --- a/fs/dlm/dlm_internal.h +++ b/fs/dlm/dlm_internal.h @@ -216,6 +216,7 @@ struct dlm_args { #define DLM_IFL_ENDOFLIFE 0x00200000 #define DLM_IFL_WATCH_TIMEWARN 0x00400000 #define DLM_IFL_TIMEOUT_CANCEL 0x00800000 +#define DLM_IFL_DEADLOCK_CANCEL 0x01000000 #define DLM_IFL_USER 0x00000001 #define DLM_IFL_ORPHAN 0x00000002 diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c index df91578145d1..de943afacb37 100644 --- a/fs/dlm/lock.c +++ b/fs/dlm/lock.c @@ -300,6 +300,11 @@ static void queue_cast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv) rv = -ETIMEDOUT; } + if (rv == -DLM_ECANCEL && (lkb->lkb_flags & DLM_IFL_DEADLOCK_CANCEL)) { + lkb->lkb_flags &= ~DLM_IFL_DEADLOCK_CANCEL; + rv = -EDEADLK; + } + lkb->lkb_lksb->sb_status = rv; lkb->lkb_lksb->sb_flags = lkb->lkb_sbflags; @@ -4450,6 +4455,54 @@ int dlm_user_cancel(struct dlm_ls *ls, struct dlm_user_args *ua_tmp, return error; } +int dlm_user_deadlock(struct dlm_ls *ls, uint32_t flags, uint32_t lkid) +{ + struct dlm_lkb *lkb; + struct dlm_args args; + struct dlm_user_args *ua; + struct dlm_rsb *r; + int error; + + dlm_lock_recovery(ls); + + error = find_lkb(ls, lkid, &lkb); + if (error) + goto out; + + ua = (struct dlm_user_args *)lkb->lkb_astparam; + + error = set_unlock_args(flags, ua, &args); + if (error) + goto out_put; + + /* same as cancel_lock(), but set DEADLOCK_CANCEL after lock_rsb */ + + r = lkb->lkb_resource; + hold_rsb(r); + lock_rsb(r); + + error = validate_unlock_args(lkb, &args); + if (error) + goto out_r; + lkb->lkb_flags |= DLM_IFL_DEADLOCK_CANCEL; + + error = _cancel_lock(r, lkb); + out_r: + unlock_rsb(r); + put_rsb(r); + + if (error == -DLM_ECANCEL) + error = 0; + /* from validate_unlock_args() */ + if (error == -EBUSY) + error = 0; + out_put: + dlm_put_lkb(lkb); + out: + dlm_unlock_recovery(ls); + return error; +} + /* lkb's that are removed from the waiters list by revert are just left on the orphans list with the granted orphan locks, to be freed by purge */ diff --git a/fs/dlm/lock.h b/fs/dlm/lock.h index 99ab4635074e..1720313c22df 100644 --- a/fs/dlm/lock.h +++ b/fs/dlm/lock.h @@ -49,6 +49,7 @@ int dlm_user_cancel(struct dlm_ls *ls, struct dlm_user_args *ua_tmp, uint32_t flags, uint32_t lkid); int dlm_user_purge(struct dlm_ls *ls, struct dlm_user_proc *proc, int nodeid, int pid); +int dlm_user_deadlock(struct dlm_ls *ls, uint32_t flags, uint32_t lkid); void dlm_clear_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc); static inline int is_master(struct dlm_rsb *r) diff --git a/fs/dlm/user.c b/fs/dlm/user.c index 329da1b5285f..6438941ab1f8 100644 --- a/fs/dlm/user.c +++ b/fs/dlm/user.c @@ -156,6 +156,7 @@ static int lkb_is_endoflife(struct dlm_lkb *lkb, int sb_status, int type) return 1; case -DLM_ECANCEL: case -ETIMEDOUT: + case -EDEADLK: if (lkb->lkb_grmode == DLM_LOCK_IV) return 1; break; @@ -320,6 +321,22 @@ static int device_user_unlock(struct dlm_user_proc *proc, return error; } +static int device_user_deadlock(struct dlm_user_proc *proc, + struct dlm_lock_params *params) +{ + struct dlm_ls *ls; + int error; + + ls = dlm_find_lockspace_local(proc->lockspace); + if (!ls) + return -ENOENT; + + error = dlm_user_deadlock(ls, params->flags, params->lkid); + + dlm_put_lockspace(ls); + return error; +} + static int create_misc_device(struct dlm_ls *ls, char *name) { int error, len; @@ -545,6 +562,14 @@ static ssize_t device_write(struct file *file, const char __user *buf, error = device_user_unlock(proc, &kbuf->i.lock); break; + case DLM_USER_DEADLOCK: + if (!proc) { + log_print("no locking on control device"); + goto out_sig; + } + error = device_user_deadlock(proc, &kbuf->i.lock); + break; + case DLM_USER_CREATE_LOCKSPACE: if (proc) { log_print("create/remove only on control device"); diff --git a/include/linux/dlm_device.h b/include/linux/dlm_device.h index f7b9b57348a8..9642277a152a 100644 --- a/include/linux/dlm_device.h +++ b/include/linux/dlm_device.h @@ -92,6 +92,7 @@ struct dlm_lock_result { #define DLM_USER_CREATE_LOCKSPACE 4 #define DLM_USER_REMOVE_LOCKSPACE 5 #define DLM_USER_PURGE 6 +#define DLM_USER_DEADLOCK 7 /* Arbitrary length restriction */ #define MAX_LS_NAME_LEN 64 -- 2.20.1