From 3e1d1d28d99dabe63c64f7f40f1ca1d646de1f73 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Fri, 24 Jun 2005 23:13:50 -0700 Subject: [PATCH] Cleanup patch for process freezing 1. Establish a simple API for process freezing defined in linux/include/sched.h: frozen(process) Check for frozen process freezing(process) Check if a process is being frozen freeze(process) Tell a process to freeze (go to refrigerator) thaw_process(process) Restart process frozen_process(process) Process is frozen now 2. Remove all references to PF_FREEZE and PF_FROZEN from all kernel sources except sched.h 3. Fix numerous locations where try_to_freeze is manually done by a driver 4. Remove the argument that is no longer necessary from two function calls. 5. Some whitespace cleanup 6. Clear potential race in refrigerator (provides an open window of PF_FREEZE cleared before setting PF_FROZEN, recalc_sigpending does not check PF_FROZEN). This patch does not address the problem of freeze_processes() violating the rule that a task may only modify its own flags by setting PF_FREEZE. This is not clean in an SMP environment. freeze(process) is therefore not SMP safe! Signed-off-by: Christoph Lameter Signed-off-by: Linus Torvalds --- fs/afs/kafsasyncd.c | 2 +- fs/afs/kafstimod.c | 2 +- fs/jbd/journal.c | 4 ++-- fs/jfs/jfs_logmgr.c | 4 ++-- fs/jfs/jfs_txnmgr.c | 8 ++++---- fs/lockd/clntproc.c | 2 +- fs/xfs/linux-2.6/xfs_buf.c | 4 ++-- fs/xfs/linux-2.6/xfs_super.c | 2 +- 8 files changed, 14 insertions(+), 14 deletions(-) (limited to 'fs') diff --git a/fs/afs/kafsasyncd.c b/fs/afs/kafsasyncd.c index 6fc88ae8ad94..7ac07d0d47b9 100644 --- a/fs/afs/kafsasyncd.c +++ b/fs/afs/kafsasyncd.c @@ -116,7 +116,7 @@ static int kafsasyncd(void *arg) remove_wait_queue(&kafsasyncd_sleepq, &myself); set_current_state(TASK_RUNNING); - try_to_freeze(PF_FREEZE); + try_to_freeze(); /* discard pending signals */ afs_discard_my_signals(); diff --git a/fs/afs/kafstimod.c b/fs/afs/kafstimod.c index 86e710dd057e..65bc05ab8182 100644 --- a/fs/afs/kafstimod.c +++ b/fs/afs/kafstimod.c @@ -91,7 +91,7 @@ static int kafstimod(void *arg) complete_and_exit(&kafstimod_dead, 0); } - try_to_freeze(PF_FREEZE); + try_to_freeze(); /* discard pending signals */ afs_discard_my_signals(); diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c index 1e6f2e2ad4a3..5e7b43949517 100644 --- a/fs/jbd/journal.c +++ b/fs/jbd/journal.c @@ -167,7 +167,7 @@ loop: } wake_up(&journal->j_wait_done_commit); - if (current->flags & PF_FREEZE) { + if (freezing(current)) { /* * The simpler the better. Flushing journal isn't a * good idea, because that depends on threads that may @@ -175,7 +175,7 @@ loop: */ jbd_debug(1, "Now suspending kjournald\n"); spin_unlock(&journal->j_state_lock); - refrigerator(PF_FREEZE); + refrigerator(); spin_lock(&journal->j_state_lock); } else { /* diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c index 7c8387ed4192..79d07624bfe1 100644 --- a/fs/jfs/jfs_logmgr.c +++ b/fs/jfs/jfs_logmgr.c @@ -2359,9 +2359,9 @@ int jfsIOWait(void *arg) lbmStartIO(bp); spin_lock_irq(&log_redrive_lock); } - if (current->flags & PF_FREEZE) { + if (freezing(current)) { spin_unlock_irq(&log_redrive_lock); - refrigerator(PF_FREEZE); + refrigerator(); } else { add_wait_queue(&jfs_IO_thread_wait, &wq); set_current_state(TASK_INTERRUPTIBLE); diff --git a/fs/jfs/jfs_txnmgr.c b/fs/jfs/jfs_txnmgr.c index 8cbaaff1d5fa..121c981ff453 100644 --- a/fs/jfs/jfs_txnmgr.c +++ b/fs/jfs/jfs_txnmgr.c @@ -2788,9 +2788,9 @@ int jfs_lazycommit(void *arg) /* In case a wakeup came while all threads were active */ jfs_commit_thread_waking = 0; - if (current->flags & PF_FREEZE) { + if (freezing(current)) { LAZY_UNLOCK(flags); - refrigerator(PF_FREEZE); + refrigerator(); } else { DECLARE_WAITQUEUE(wq, current); @@ -2987,9 +2987,9 @@ int jfs_sync(void *arg) /* Add anon_list2 back to anon_list */ list_splice_init(&TxAnchor.anon_list2, &TxAnchor.anon_list); - if (current->flags & PF_FREEZE) { + if (freezing(current)) { TXN_UNLOCK(); - refrigerator(PF_FREEZE); + refrigerator(); } else { DECLARE_WAITQUEUE(wq, current); diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c index fd77ed1d710d..14b3ce87fa29 100644 --- a/fs/lockd/clntproc.c +++ b/fs/lockd/clntproc.c @@ -313,7 +313,7 @@ static int nlm_wait_on_grace(wait_queue_head_t *queue) prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE); if (!signalled ()) { schedule_timeout(NLMCLNT_GRACE_WAIT); - try_to_freeze(PF_FREEZE); + try_to_freeze(); if (!signalled ()) status = 0; } diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c index c60e69431e11..df0cba239dd5 100644 --- a/fs/xfs/linux-2.6/xfs_buf.c +++ b/fs/xfs/linux-2.6/xfs_buf.c @@ -1771,9 +1771,9 @@ xfsbufd( INIT_LIST_HEAD(&tmp); do { - if (unlikely(current->flags & PF_FREEZE)) { + if (unlikely(freezing(current))) { xfsbufd_force_sleep = 1; - refrigerator(PF_FREEZE); + refrigerator(); } else { xfsbufd_force_sleep = 0; } diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c index 5fe9af38aa20..f6dd7de25927 100644 --- a/fs/xfs/linux-2.6/xfs_super.c +++ b/fs/xfs/linux-2.6/xfs_super.c @@ -483,7 +483,7 @@ xfssyncd( set_current_state(TASK_INTERRUPTIBLE); timeleft = schedule_timeout(timeleft); /* swsusp */ - try_to_freeze(PF_FREEZE); + try_to_freeze(); if (vfsp->vfs_flag & VFS_UMOUNT) break; -- cgit v1.2.3