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lockd: Fix server-side lock blocking code

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Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2006-03-20 13:44:38 -05:00
parent 0996905f93
commit 09c7938c56
1 changed files with 40 additions and 33 deletions
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73
fs/lockd/svclock.c
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@ -193,6 +193,7 @@ nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file,
goto failed_free;
/* Set notifier function for VFS, and init args */
block->b_call.a_args.lock.fl.fl_flags |= FL_SLEEP;
block->b_call.a_args.lock.fl.fl_lmops = &nlmsvc_lock_operations;
block->b_call.a_args.cookie = *cookie; /* see above */
@ -228,19 +229,18 @@ failed:
* can be closed hereafter.
*/
static int
nlmsvc_delete_block(struct nlm_block *block, int unlock)
nlmsvc_delete_block(struct nlm_block *block)
{
struct file_lock *fl = &block->b_call.a_args.lock.fl;
struct nlm_file *file = block->b_file;
struct nlm_block **bp;
int status = 0;
int status;
dprintk("lockd: deleting block %p...\n", block);
/* Remove block from list */
nlmsvc_remove_block(block);
if (unlock)
status = posix_unblock_lock(file->f_file, fl);
status = posix_unblock_lock(file->f_file, fl);
/* If the block is in the middle of a GRANT callback,
* don't kill it yet. */
@ -282,7 +282,7 @@ nlmsvc_traverse_blocks(struct nlm_host *host, struct nlm_file *file, int action)
block->b_host->h_inuse = 1;
else if (action == NLM_ACT_UNLOCK) {
if (host == NULL || host == block->b_host)
nlmsvc_delete_block(block, 1);
nlmsvc_delete_block(block);
}
}
up(&file->f_sema);
@ -297,7 +297,7 @@ u32
nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file,
struct nlm_lock *lock, int wait, struct nlm_cookie *cookie)
{
struct nlm_block *block;
struct nlm_block *block, *newblock = NULL;
int error;
u32 ret;
@ -310,59 +310,65 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file,
wait);
/* Get existing block (in case client is busy-waiting) */
block = nlmsvc_lookup_block(file, lock, 0);
lock->fl.fl_flags &= ~FL_SLEEP;
again:
/* Lock file against concurrent access */
down(&file->f_sema);
/* Get existing block (in case client is busy-waiting) */
block = nlmsvc_lookup_block(file, lock, 0);
if (block == NULL) {
if (newblock != NULL)
lock = &newblock->b_call.a_args.lock.fl;
} else
lock = &block->b_call.a_args.lock.fl;
error = posix_lock_file(file->f_file, &lock->fl);
lock->fl.fl_flags &= ~FL_SLEEP;
dprintk("lockd: posix_lock_file returned %d\n", error);
if (error != -EAGAIN) {
if (block)
nlmsvc_delete_block(block, 0);
up(&file->f_sema);
switch(-error) {
switch(error) {
case 0:
ret = nlm_granted;
goto out;
case EDEADLK:
case -EAGAIN:
break;
case -EDEADLK:
ret = nlm_deadlock;
goto out;
default: /* includes ENOLCK */
ret = nlm_lck_denied_nolocks;
goto out;
}
}
if (!wait) {
ret = nlm_lck_denied;
goto out_unlock;
}
ret = nlm_lck_denied;
if (!wait)
goto out;
ret = nlm_lck_blocked;
if (block != NULL)
goto out;
/* If we don't have a block, create and initialize it. Then
* retry because we may have slept in kmalloc. */
/* We have to release f_sema as nlmsvc_create_block may try to
* to claim it while doing host garbage collection */
if (block == NULL) {
if (newblock == NULL) {
up(&file->f_sema);
dprintk("lockd: blocking on this lock (allocating).\n");
if (!(block = nlmsvc_create_block(rqstp, file, lock, cookie)))
if (!(newblock = nlmsvc_create_block(rqstp, file, lock, cookie)))
return nlm_lck_denied_nolocks;
goto again;
}
/* Append to list of blocked */
nlmsvc_insert_block(block, NLM_NEVER);
nlmsvc_insert_block(newblock, NLM_NEVER);
newblock = NULL;
ret = nlm_lck_blocked;
out_unlock:
up(&file->f_sema);
out:
up(&file->f_sema);
if (newblock != NULL)
nlmsvc_delete_block(newblock);
dprintk("lockd: nlmsvc_lock returned %u\n", ret);
return ret;
}
@ -445,7 +451,7 @@ nlmsvc_cancel_blocked(struct nlm_file *file, struct nlm_lock *lock)
down(&file->f_sema);
if ((block = nlmsvc_lookup_block(file, lock, 1)) != NULL)
status = nlmsvc_delete_block(block, 1);
status = nlmsvc_delete_block(block);
up(&file->f_sema);
return status ? nlm_lck_denied : nlm_granted;
}
@ -519,7 +525,11 @@ nlmsvc_grant_blocked(struct nlm_block *block)
}
/* Try the lock operation again */
posix_unblock_lock(file->f_file, &lock->fl);
lock->fl.fl_flags |= FL_SLEEP;
error = posix_lock_file(file->f_file, &lock->fl);
lock->fl.fl_flags &= ~FL_SLEEP;
switch (error) {
case 0:
break;
@ -630,11 +640,8 @@ nlmsvc_grant_reply(struct svc_rqst *rqstp, struct nlm_cookie *cookie, u32 status
} else {
/* Lock is now held by client, or has been rejected.
* In both cases, the block should be removed. */
nlmsvc_delete_block(block);
up(&file->f_sema);
if (status == NLM_LCK_GRANTED)
nlmsvc_delete_block(block, 0);
else
nlmsvc_delete_block(block, 1);
}
}
nlm_release_file(file);
@ -661,7 +668,7 @@ nlmsvc_retry_blocked(void)
dprintk("nlmsvc_retry_blocked(%p, when=%ld, done=%d)\n",
block, block->b_when, block->b_done);
if (block->b_done)
nlmsvc_delete_block(block, 0);
nlmsvc_delete_block(block);
else
nlmsvc_grant_blocked(block);
}