Hi,
Sorry for the delay,
On Thu, 2007-04-05 at 19:41 -0400, J. Bruce Fields wrote:
> From: Marc Eshel <eshel@xxxxxxxxxxxxxxx> - unquoted
>
> Add NFS lock support to GFS2.
>
> Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxxxxxx>
Acked-by: Steven Whitehouse <swhiteho@xxxxxxxxxx>
Steve.
> ---
> fs/gfs2/locking/dlm/plock.c | 104 ++++++++++++++++++++++++++++++++++++++----
> fs/gfs2/ops_file.c | 5 ++
> 2 files changed, 99 insertions(+), 10 deletions(-)
>
> diff --git a/fs/gfs2/locking/dlm/plock.c b/fs/gfs2/locking/dlm/plock.c
> index 1dd4215..1160cde 100644
> --- a/fs/gfs2/locking/dlm/plock.c
> +++ b/fs/gfs2/locking/dlm/plock.c
> @@ -25,6 +25,14 @@ struct plock_op {
> struct gdlm_plock_info info;
> };
>
> +struct plock_xop {
> + struct plock_op xop;
> + void *callback;
> + void *fl;
> + void *file;
> +};
> +
> +
> static inline void set_version(struct gdlm_plock_info *info)
> {
> info->version[0] = GDLM_PLOCK_VERSION_MAJOR;
> @@ -64,12 +72,14 @@ int gdlm_plock(void *lockspace, struct lm_lockname *name,
> {
> struct gdlm_ls *ls = lockspace;
> struct plock_op *op;
> + struct plock_xop *xop;
> int rv;
>
> - op = kzalloc(sizeof(*op), GFP_KERNEL);
> - if (!op)
> + xop = kzalloc(sizeof(*xop), GFP_KERNEL);
> + if (!xop)
> return -ENOMEM;
>
> + op = &xop->xop;
> op->info.optype = GDLM_PLOCK_OP_LOCK;
> op->info.pid = fl->fl_pid;
> op->info.ex = (fl->fl_type == F_WRLCK);
> @@ -79,9 +89,20 @@ int gdlm_plock(void *lockspace, struct lm_lockname *name,
> op->info.start = fl->fl_start;
> op->info.end = fl->fl_end;
> op->info.owner = (__u64)(long) fl->fl_owner;
> + if (fl->fl_lmops && fl->fl_lmops->fl_notify) {
> + xop->callback = fl->fl_lmops->fl_notify;
> + /* might need to make a copy */
> + xop->fl = fl;
> + xop->file = file;
> + } else
> + xop->callback = NULL;
>
> send_op(op);
> - wait_event(recv_wq, (op->done != 0));
> +
> + if (xop->callback == NULL)
> + wait_event(recv_wq, (op->done != 0));
> + else
> + return -EINPROGRESS;
>
> spin_lock(&ops_lock);
> if (!list_empty(&op->list)) {
> @@ -99,7 +120,60 @@ int gdlm_plock(void *lockspace, struct lm_lockname *name,
> (unsigned long long)name->ln_number);
> }
>
> - kfree(op);
> + kfree(xop);
> + return rv;
> +}
> +
> +/* Returns failure iff a succesful lock operation should be canceled */
> +static int gdlm_plock_callback(struct plock_op *op)
> +{
> + struct file *file;
> + struct file_lock *fl;
> + int (*notify)(void *, void *, int) = NULL;
> + struct plock_xop *xop = (struct plock_xop *)op;
> + int rv = 0;
> +
> + spin_lock(&ops_lock);
> + if (!list_empty(&op->list)) {
> + printk(KERN_INFO "plock op on list\n");
> + list_del(&op->list);
> + }
> + spin_unlock(&ops_lock);
> +
> + /* check if the following 2 are still valid or make a copy */
> + file = xop->file;
> + fl = xop->fl;
> + notify = xop->callback;
> +
> + if (op->info.rv) {
> + notify(fl, NULL, op->info.rv);
> + goto out;
> + }
> +
> + /* got fs lock; bookkeep locally as well: */
> + if (posix_lock_file(file, fl, NULL)) {
> + /*
> + * This can only happen in the case of kmalloc() failure.
> + * The filesystem's own lock is the authoritative lock,
> + * so a failure to get the lock locally is not a disaster.
> + * As long as GFS cannot reliably cancel locks (especially
> + * in a low-memory situation), we're better off ignoring
> + * this failure than trying to recover.
> + */
> + log_error("gdlm_plock: vfs lock error file %p fl %p",
> + file, fl);
> + }
> +
> + rv = notify(fl, NULL, 0);
> + if (rv) {
> + /* XXX: We need to cancel the fs lock here: */
> + printk("gfs2 lock granted after lock request failed;"
> + " dangling lock!\n");
> + goto out;
> + }
> +
> +out:
> + kfree(xop);
> return rv;
> }
>
> @@ -138,6 +212,9 @@ int gdlm_punlock(void *lockspace, struct lm_lockname *name,
>
> rv = op->info.rv;
>
> + if (rv == -ENOENT)
> + rv = 0;
> +
> kfree(op);
> return rv;
> }
> @@ -161,6 +238,7 @@ int gdlm_plock_get(void *lockspace, struct lm_lockname *name,
> op->info.start = fl->fl_start;
> op->info.end = fl->fl_end;
>
> +
> send_op(op);
> wait_event(recv_wq, (op->done != 0));
>
> @@ -173,9 +251,10 @@ int gdlm_plock_get(void *lockspace, struct lm_lockname *name,
>
> rv = op->info.rv;
>
> - if (rv == 0)
> - fl->fl_type = F_UNLCK;
> - else if (rv > 0) {
> + fl->fl_type = F_UNLCK;
> + if (rv == -ENOENT)
> + rv = 0;
> + else if (rv == 0 && op->info.pid != fl->fl_pid) {
> fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;
> fl->fl_pid = op->info.pid;
> fl->fl_start = op->info.start;
> @@ -243,9 +322,14 @@ static ssize_t dev_write(struct file *file, const char __user *u, size_t count,
> }
> spin_unlock(&ops_lock);
>
> - if (found)
> - wake_up(&recv_wq);
> - else
> + if (found) {
> + struct plock_xop *xop;
> + xop = (struct plock_xop *)op;
> + if (xop->callback)
> + count = gdlm_plock_callback(op);
> + else
> + wake_up(&recv_wq);
> + } else
> printk(KERN_INFO "gdlm dev_write no op %x %llx\n", info.fsid,
> (unsigned long long)info.number);
> return count;
> diff --git a/fs/gfs2/ops_file.c b/fs/gfs2/ops_file.c
> index 48b248d..329c4dc 100644
> --- a/fs/gfs2/ops_file.c
> +++ b/fs/gfs2/ops_file.c
> @@ -520,6 +520,11 @@ static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
> }
> }
>
> + if (cmd == F_CANCELLK) {
> + /* Hack: */
> + cmd = F_SETLK;
> + fl->fl_type = F_UNLCK;
> + }
> if (IS_GETLK(cmd))
> return gfs2_lm_plock_get(sdp, &name, file, fl);
> else if (fl->fl_type == F_UNLCK)
-
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