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