lockd: Add refcounting to struct nlm_block (6849c0ca) · Commits · e / devices / android_kernel_xiaomi_markw

fs/lockd/svclock.c

+45 −49

Original line number	Diff line number	Diff line
		@@ -39,6 +39,7 @@
		#define nlm_deadlock nlm_lck_denied
		#endif

		static void nlmsvc_release_block(struct nlm_block *block);
		static void nlmsvc_insert_block(struct nlm_block *block, unsigned long);
		static int nlmsvc_remove_block(struct nlm_block *block);

		@@ -58,6 +59,7 @@ nlmsvc_insert_block(struct nlm_block *block, unsigned long when)
		struct nlm_block *bp, b;

		dprintk("lockd: nlmsvc_insert_block(%p, %ld)\n", block, when);
		kref_get(&block->b_count);
		if (block->b_queued)
		nlmsvc_remove_block(block);
		bp = &nlm_blocked;
		@@ -90,6 +92,7 @@ nlmsvc_remove_block(struct nlm_block *block)
		if (b == block) {
		*bp = block->b_next;
		block->b_queued = 0;
		nlmsvc_release_block(block);
		return 1;
		}
		}
		@@ -123,6 +126,7 @@ nlmsvc_lookup_block(struct nlm_file file, struct nlm_lock lock, int remove)
		*head = block->b_next;
		block->b_queued = 0;
		}
		kref_get(&block->b_count);
		return block;
		}
		}
		@@ -155,6 +159,8 @@ nlmsvc_find_block(struct nlm_cookie cookie, struct sockaddr_in sin)
		break;
		}

		if (block != NULL)
		kref_get(&block->b_count);
		return block;
		}

		@@ -188,6 +194,7 @@ nlmsvc_create_block(struct svc_rqst rqstp, struct nlm_file file,
		memset(block, 0, sizeof(*block));
		locks_init_lock(&block->b_call.a_args.lock.fl);
		locks_init_lock(&block->b_call.a_res.lock.fl);
		kref_init(&block->b_count);

		if (!nlmclnt_setgrantargs(&block->b_call, lock))
		goto failed_free;
		@@ -228,28 +235,25 @@ failed:
		* It is the caller's responsibility to check whether the file
		* can be closed hereafter.
		*/
		static int
		nlmsvc_delete_block(struct nlm_block *block)
		static int nlmsvc_unlink_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;

		dprintk("lockd: deleting block %p...\n", block);
		dprintk("lockd: unlinking block %p...\n", block);

		/* Remove block from list */
		status = posix_unblock_lock(block->b_file->f_file, &block->b_call.a_args.lock.fl);
		nlmsvc_remove_block(block);
		status = posix_unblock_lock(file->f_file, fl);

		/* If the block is in the middle of a GRANT callback,
		* don't kill it yet. */
		if (block->b_incall) {
		nlmsvc_insert_block(block, NLM_NEVER);
		block->b_done = 1;
		return status;
		}

		static void nlmsvc_free_block(struct kref *kref)
		{
		struct nlm_block *block = container_of(kref, struct nlm_block, b_count);
		struct nlm_file *file = block->b_file;
		struct nlm_block **bp;

		dprintk("lockd: freeing block %p...\n", block);

		/* Remove block from file's list of blocks */
		for (bp = &file->f_blocks; bp; bp = &(bp)->b_fnext) {
		if (*bp == block) {
		@@ -262,7 +266,12 @@ nlmsvc_delete_block(struct nlm_block *block)
		nlm_release_host(block->b_host);
		nlmclnt_freegrantargs(&block->b_call);
		kfree(block);
		return status;
		}

		static void nlmsvc_release_block(struct nlm_block *block)
		{
		if (block != NULL)
		kref_put(&block->b_count, nlmsvc_free_block);
		}

		/*
		@@ -282,7 +291,7 @@ 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);
		nlmsvc_unlink_block(block);
		}
		}
		up(&file->f_sema);
		@@ -318,9 +327,9 @@ again:
		block = nlmsvc_lookup_block(file, lock, 0);
		if (block == NULL) {
		if (newblock != NULL)
		lock = &newblock->b_call.a_args.lock.fl;
		lock = &newblock->b_call.a_args.lock;
		} else
		lock = &block->b_call.a_args.lock.fl;
		lock = &block->b_call.a_args.lock;

		error = posix_lock_file(file->f_file, &lock->fl);
		lock->fl.fl_flags &= ~FL_SLEEP;
		@@ -363,12 +372,10 @@ again:

		/* Append to list of blocked */
		nlmsvc_insert_block(newblock, NLM_NEVER);
		newblock = NULL;

		out:
		up(&file->f_sema);
		if (newblock != NULL)
		nlmsvc_delete_block(newblock);
		nlmsvc_release_block(newblock);
		nlmsvc_release_block(block);
		dprintk("lockd: nlmsvc_lock returned %u\n", ret);
		return ret;
		}
		@@ -450,8 +457,10 @@ nlmsvc_cancel_blocked(struct nlm_file file, struct nlm_lock lock)
		(long long)lock->fl.fl_end);

		down(&file->f_sema);
		if ((block = nlmsvc_lookup_block(file, lock, 1)) != NULL)
		status = nlmsvc_delete_block(block);
		if ((block = nlmsvc_lookup_block(file, lock, 1)) != NULL) {
		status = nlmsvc_unlink_block(block);
		nlmsvc_release_block(block);
		}
		up(&file->f_sema);
		return status ? nlm_lck_denied : nlm_granted;
		}
		@@ -514,7 +523,7 @@ nlmsvc_grant_blocked(struct nlm_block *block)
		down(&file->f_sema);

		/* Unlink block request from list */
		nlmsvc_remove_block(block);
		nlmsvc_unlink_block(block);

		/* If b_granted is true this means we've been here before.
		* Just retry the grant callback, possibly refreshing the RPC
		@@ -525,7 +534,6 @@ 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;
		@@ -548,16 +556,15 @@ callback:
		/* Lock was granted by VFS. */
		dprintk("lockd: GRANTing blocked lock.\n");
		block->b_granted = 1;
		block->b_incall = 1;

		/* Schedule next grant callback in 30 seconds */
		nlmsvc_insert_block(block, 30 * HZ);

		/* Call the client */
		nlm_get_host(block->b_call.a_host);
		kref_get(&block->b_count);
		if (nlmsvc_async_call(&block->b_call, NLMPROC_GRANTED_MSG,
		&nlmsvc_grant_ops) < 0)
		nlm_release_host(block->b_call.a_host);
		nlmsvc_release_block(block);
		out_unlock:
		up(&file->f_sema);
		}
		@@ -573,20 +580,10 @@ out_unlock:
		static void nlmsvc_grant_callback(struct rpc_task task, void data)
		{
		struct nlm_rqst *call = data;
		struct nlm_block *block;
		struct nlm_block *block = container_of(call, struct nlm_block, b_call);
		unsigned long timeout;
		struct sockaddr_in *peer_addr = RPC_PEERADDR(task->tk_client);

		dprintk("lockd: GRANT_MSG RPC callback\n");
		dprintk("callback: looking for cookie %s, host (%u.%u.%u.%u)\n",
		nlmdbg_cookie2a(&call->a_args.cookie),
		NIPQUAD(peer_addr->sin_addr.s_addr));
		if (!(block = nlmsvc_find_block(&call->a_args.cookie, peer_addr))) {
		dprintk("lockd: no block for cookie %s, host (%u.%u.%u.%u)\n",
		nlmdbg_cookie2a(&call->a_args.cookie),
		NIPQUAD(peer_addr->sin_addr.s_addr));
		return;
		}

		/* Technically, we should down the file semaphore here. Since we
		* move the block towards the head of the queue only, no harm
		@@ -603,9 +600,7 @@ static void nlmsvc_grant_callback(struct rpc_task task, void data)
		}
		nlmsvc_insert_block(block, timeout);
		svc_wake_up(block->b_daemon);
		block->b_incall = 0;

		nlm_release_host(call->a_host);
		nlmsvc_release_block(block);
		}

		static const struct rpc_call_ops nlmsvc_grant_ops = {
		@@ -631,20 +626,19 @@ nlmsvc_grant_reply(struct svc_rqst rqstp, struct nlm_cookie cookie, u32 status

		file->f_count++;
		down(&file->f_sema);
		block = nlmsvc_find_block(cookie, &rqstp->rq_addr);
		if (block) {
		if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
		/* Try again in a couple of seconds */
		nlmsvc_insert_block(block, 10 * HZ);
		up(&file->f_sema);
		} 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);
		nlmsvc_unlink_block(block);
		}
		}
		up(&file->f_sema);
		nlm_release_file(file);
		nlmsvc_release_block(block);
		}

		/*
		@@ -667,10 +661,12 @@ nlmsvc_retry_blocked(void)
		break;
		dprintk("nlmsvc_retry_blocked(%p, when=%ld, done=%d)\n",
		block, block->b_when, block->b_done);
		kref_get(&block->b_count);
		if (block->b_done)
		nlmsvc_delete_block(block);
		nlmsvc_unlink_block(block);
		else
		nlmsvc_grant_blocked(block);
		nlmsvc_release_block(block);
		}

		if ((block = nlm_blocked) && block->b_when != NLM_NEVER)

include/linux/lockd/lockd.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -14,6 +14,7 @@
		#include <linux/config.h>
		#include <linux/in.h>
		#include <linux/fs.h>
		#include <linux/kref.h>
		#include <linux/utsname.h>
		#include <linux/nfsd/nfsfh.h>
		#include <linux/lockd/bind.h>
		@@ -110,6 +111,7 @@ struct nlm_file {
		*/
		#define NLM_NEVER (~(unsigned long) 0)
		struct nlm_block {
		struct kref b_count; /* Reference count */
		struct nlm_block * b_next; /* linked list (all blocks) */
		struct nlm_block * b_fnext; /* linked list (per file) */
		struct nlm_rqst b_call; /* RPC args & callback info */
		@@ -119,7 +121,6 @@ struct nlm_block {
		unsigned int b_id; /* block id */
		unsigned char b_queued; /* re-queued */
		unsigned char b_granted; /* VFS granted lock */
		unsigned char b_incall; /* doing callback */
		unsigned char b_done; /* callback complete */
		struct nlm_file * b_file; /* file in question */
		};