From 0f8e0d9a317406612700426fad3efab0b7bbc467 Mon Sep 17 00:00:00 2001 From: David Teigland Date: Wed, 6 Aug 2008 13:30:24 -0500 Subject: dlm: allow multiple lockspace creates Add a count for lockspace create and release so that create can be called multiple times to use the lockspace from different places. Also add the new flag DLM_LSFL_NEWEXCL to create a lockspace with the previous behavior of returning -EEXIST if the lockspace already exists. Signed-off-by: David Teigland --- fs/dlm/lockspace.c | 107 +++++++++++++++++++++++++++++++++++------------------ 1 file changed, 70 insertions(+), 37 deletions(-) (limited to 'fs/dlm/lockspace.c') diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c index 499e167..56eae4e 100644 --- a/fs/dlm/lockspace.c +++ b/fs/dlm/lockspace.c @@ -2,7 +2,7 @@ ******************************************************************************* ** ** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. -** Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved. +** Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. ** ** This copyrighted material is made available to anyone wishing to use, ** modify, copy, or redistribute it subject to the terms and conditions @@ -23,6 +23,7 @@ #include "lock.h" #include "recover.h" #include "requestqueue.h" +#include "user.h" static int ls_count; static struct mutex ls_lock; @@ -246,23 +247,6 @@ static void dlm_scand_stop(void) kthread_stop(scand_task); } -static struct dlm_ls *dlm_find_lockspace_name(char *name, int namelen) -{ - struct dlm_ls *ls; - - spin_lock(&lslist_lock); - - list_for_each_entry(ls, &lslist, ls_list) { - if (ls->ls_namelen == namelen && - memcmp(ls->ls_name, name, namelen) == 0) - goto out; - } - ls = NULL; - out: - spin_unlock(&lslist_lock); - return ls; -} - struct dlm_ls *dlm_find_lockspace_global(uint32_t id) { struct dlm_ls *ls; @@ -327,6 +311,7 @@ static void remove_lockspace(struct dlm_ls *ls) for (;;) { spin_lock(&lslist_lock); if (ls->ls_count == 0) { + WARN_ON(ls->ls_create_count != 0); list_del(&ls->ls_list); spin_unlock(&lslist_lock); return; @@ -381,7 +366,7 @@ static int new_lockspace(char *name, int namelen, void **lockspace, uint32_t flags, int lvblen) { struct dlm_ls *ls; - int i, size, error = -ENOMEM; + int i, size, error; int do_unreg = 0; if (namelen > DLM_LOCKSPACE_LEN) @@ -393,12 +378,32 @@ static int new_lockspace(char *name, int namelen, void **lockspace, if (!try_module_get(THIS_MODULE)) return -EINVAL; - ls = dlm_find_lockspace_name(name, namelen); - if (ls) { - *lockspace = ls; + error = 0; + + spin_lock(&lslist_lock); + list_for_each_entry(ls, &lslist, ls_list) { + WARN_ON(ls->ls_create_count <= 0); + if (ls->ls_namelen != namelen) + continue; + if (memcmp(ls->ls_name, name, namelen)) + continue; + if (flags & DLM_LSFL_NEWEXCL) { + error = -EEXIST; + break; + } + ls->ls_create_count++; module_put(THIS_MODULE); - return -EEXIST; + error = 1; /* not an error, return 0 */ + break; } + spin_unlock(&lslist_lock); + + if (error < 0) + goto out; + if (error) + goto ret_zero; + + error = -ENOMEM; ls = kzalloc(sizeof(struct dlm_ls) + namelen, GFP_KERNEL); if (!ls) @@ -418,8 +423,9 @@ static int new_lockspace(char *name, int namelen, void **lockspace, ls->ls_allocation = GFP_KERNEL; /* ls_exflags are forced to match among nodes, and we don't - need to require all nodes to have TIMEWARN or FS set */ - ls->ls_exflags = (flags & ~(DLM_LSFL_TIMEWARN | DLM_LSFL_FS)); + need to require all nodes to have some flags set */ + ls->ls_exflags = (flags & ~(DLM_LSFL_TIMEWARN | DLM_LSFL_FS | + DLM_LSFL_NEWEXCL)); size = dlm_config.ci_rsbtbl_size; ls->ls_rsbtbl_size = size; @@ -510,6 +516,7 @@ static int new_lockspace(char *name, int namelen, void **lockspace, down_write(&ls->ls_in_recovery); spin_lock(&lslist_lock); + ls->ls_create_count = 1; list_add(&ls->ls_list, &lslist); spin_unlock(&lslist_lock); @@ -548,7 +555,7 @@ static int new_lockspace(char *name, int namelen, void **lockspace, dlm_create_debug_file(ls); log_debug(ls, "join complete"); - + ret_zero: *lockspace = ls; return 0; @@ -635,11 +642,32 @@ static int release_lockspace(struct dlm_ls *ls, int force) struct dlm_lkb *lkb; struct dlm_rsb *rsb; struct list_head *head; - int i; - int busy = lockspace_busy(ls); + int i, busy, rv; + + busy = lockspace_busy(ls); + + spin_lock(&lslist_lock); + if (ls->ls_create_count == 1) { + if (busy > force) + rv = -EBUSY; + else { + /* remove_lockspace takes ls off lslist */ + ls->ls_create_count = 0; + rv = 0; + } + } else if (ls->ls_create_count > 1) { + rv = --ls->ls_create_count; + } else { + rv = -EINVAL; + } + spin_unlock(&lslist_lock); + + if (rv) { + log_debug(ls, "release_lockspace no remove %d", rv); + return rv; + } - if (busy > force) - return -EBUSY; + dlm_device_deregister(ls); if (force < 3) do_uevent(ls, 0); @@ -720,15 +748,10 @@ static int release_lockspace(struct dlm_ls *ls, int force) dlm_clear_members(ls); dlm_clear_members_gone(ls); kfree(ls->ls_node_array); + log_debug(ls, "release_lockspace final free"); kobject_put(&ls->ls_kobj); /* The ls structure will be freed when the kobject is done with */ - mutex_lock(&ls_lock); - ls_count--; - if (!ls_count) - threads_stop(); - mutex_unlock(&ls_lock); - module_put(THIS_MODULE); return 0; } @@ -750,11 +773,21 @@ static int release_lockspace(struct dlm_ls *ls, int force) int dlm_release_lockspace(void *lockspace, int force) { struct dlm_ls *ls; + int error; ls = dlm_find_lockspace_local(lockspace); if (!ls) return -EINVAL; dlm_put_lockspace(ls); - return release_lockspace(ls, force); + + mutex_lock(&ls_lock); + error = release_lockspace(ls, force); + if (!error) + ls_count--; + else if (!ls_count) + threads_stop(); + mutex_unlock(&ls_lock); + + return error; } -- cgit v1.1