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gfs2: nfs lock support for gfs2

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Add NFS lock support to GFS2.

Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
This commit is contained in:
Marc Eshel 2006-11-14 16:37:25 -05:00 committed by J. Bruce Fields
parent 1a8322b2b0
commit 586759f03e
2 changed files with 104 additions and 10 deletions
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109
fs/gfs2/locking/dlm/plock.c
View File

@ -25,6 +25,15 @@ struct plock_op {
struct gdlm_plock_info info;
};
struct plock_xop {
struct plock_op xop;
void *callback;
void *fl;
void *file;
struct file_lock flc;
};
static inline void set_version(struct gdlm_plock_info *info)
{
info->version[0] = GDLM_PLOCK_VERSION_MAJOR;
@ -64,12 +73,14 @@ 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 +90,21 @@ 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_grant) {
xop->callback = fl->fl_lmops->fl_grant;
locks_init_lock(&xop->flc);
locks_copy_lock(&xop->flc, fl);
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 +122,63 @@ 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;
struct file_lock *flc;
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;
flc = &xop->flc;
fl = xop->fl;
notify = xop->callback;
if (op->info.rv) {
notify(flc, NULL, op->info.rv);
goto out;
}
/* got fs lock; bookkeep locally as well: */
flc->fl_flags &= ~FL_SLEEP;
if (posix_lock_file(file, flc, 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(flc, 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 +217,9 @@ int gdlm_punlock(void *lockspace, struct lm_lockname *name,
rv = op->info.rv;
if (rv == -ENOENT)
rv = 0;
kfree(op);
return rv;
}
@ -161,6 +243,7 @@ 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 +256,10 @@ 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 +327,14 @@ 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;

5
fs/gfs2/ops_file.c
View File

@ -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)