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Commit 1b4b55a1 authored by Pavel Shilovsky's avatar Pavel Shilovsky Committed by Steve French
Browse files

CIFS: Turn lock mutex into rw semaphore 



and allow several processes to walk through the lock list and read
can_cache_brlcks value if they are not going to modify them.

Signed-off-by: default avatarPavel Shilovsky <pshilovsky@etersoft.ru>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent b140799a

fs/cifs/cifsfs.c

+1 −1
Original line number Diff line number Diff line
@@ -937,7 +937,7 @@ cifs_init_once(void *inode) 
	struct cifsInodeInfo *cifsi = inode;



	inode_init_once(&cifsi->vfs_inode);

	mutex_init(&cifsi->lock_mutex);

	init_rwsem(&cifsi->lock_sem);

}



static int

fs/cifs/cifsglob.h

+1 −1
Original line number Diff line number Diff line
@@ -1000,7 +1000,7 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file); 
struct cifsInodeInfo {

	bool can_cache_brlcks;

	struct list_head llist;	/* locks helb by this inode */

	struct mutex lock_mutex;	/* protect the fields above */

	struct rw_semaphore lock_sem;	/* protect the fields above */

	/* BB add in lists for dirty pages i.e. write caching info for oplock */

	struct list_head openFileList;

	__u32 cifsAttrs; /* e.g. DOS archive bit, sparse, compressed, system */

fs/cifs/file.c

+31 −29
Original line number Diff line number Diff line
@@ -260,9 +260,9 @@ cifs_new_fileinfo(struct cifs_fid *fid, struct file *file, 
	INIT_LIST_HEAD(&fdlocks->locks);

	fdlocks->cfile = cfile;

	cfile->llist = fdlocks;

	mutex_lock(&cinode->lock_mutex);

	down_write(&cinode->lock_sem);

	list_add(&fdlocks->llist, &cinode->llist);

	mutex_unlock(&cinode->lock_mutex);

	up_write(&cinode->lock_sem);



	cfile->count = 1;

	cfile->pid = current->tgid;
@@ -351,7 +351,7 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file) 
	 * Delete any outstanding lock records. We'll lose them when the file

	 * is closed anyway.

	 */

	mutex_lock(&cifsi->lock_mutex);

	down_write(&cifsi->lock_sem);

	list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {

		list_del(&li->llist);

		cifs_del_lock_waiters(li);
@@ -359,7 +359,7 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file) 
	}

	list_del(&cifs_file->llist->llist);

	kfree(cifs_file->llist);

	mutex_unlock(&cifsi->lock_mutex);

	up_write(&cifsi->lock_sem);



	cifs_put_tlink(cifs_file->tlink);

	dput(cifs_file->dentry);
@@ -762,7 +762,7 @@ cifs_lock_test(struct cifsFileInfo *cfile, __u64 offset, __u64 length, 
	struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;

	bool exist;



	mutex_lock(&cinode->lock_mutex);

	down_read(&cinode->lock_sem);



	exist = cifs_find_lock_conflict(cfile, offset, length, type,

					&conf_lock);
@@ -779,7 +779,7 @@ cifs_lock_test(struct cifsFileInfo *cfile, __u64 offset, __u64 length, 
	else

		flock->fl_type = F_UNLCK;



	mutex_unlock(&cinode->lock_mutex);

	up_read(&cinode->lock_sem);

	return rc;

}
@@ -787,9 +787,9 @@ static void 
cifs_lock_add(struct cifsFileInfo *cfile, struct cifsLockInfo *lock)

{

	struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);

	mutex_lock(&cinode->lock_mutex);

	down_write(&cinode->lock_sem);

	list_add_tail(&lock->llist, &cfile->llist->locks);

	mutex_unlock(&cinode->lock_mutex);

	up_write(&cinode->lock_sem);

}



/*
@@ -809,13 +809,13 @@ cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock, 


try_again:

	exist = false;

	mutex_lock(&cinode->lock_mutex);

	down_write(&cinode->lock_sem);



	exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length,

					lock->type, &conf_lock);

	if (!exist && cinode->can_cache_brlcks) {

		list_add_tail(&lock->llist, &cfile->llist->locks);

		mutex_unlock(&cinode->lock_mutex);

		up_write(&cinode->lock_sem);

		return rc;

	}
@@ -825,17 +825,17 @@ cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock, 
		rc = -EACCES;

	else {

		list_add_tail(&lock->blist, &conf_lock->blist);

		mutex_unlock(&cinode->lock_mutex);

		up_write(&cinode->lock_sem);

		rc = wait_event_interruptible(lock->block_q,

					(lock->blist.prev == &lock->blist) &&

					(lock->blist.next == &lock->blist));

		if (!rc)

			goto try_again;

		mutex_lock(&cinode->lock_mutex);

		down_write(&cinode->lock_sem);

		list_del_init(&lock->blist);

	}



	mutex_unlock(&cinode->lock_mutex);

	up_write(&cinode->lock_sem);

	return rc;

}
@@ -856,7 +856,7 @@ cifs_posix_lock_test(struct file *file, struct file_lock *flock) 
	if ((flock->fl_flags & FL_POSIX) == 0)

		return 1;



	mutex_lock(&cinode->lock_mutex);

	down_read(&cinode->lock_sem);

	posix_test_lock(file, flock);



	if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) {
@@ -864,7 +864,7 @@ cifs_posix_lock_test(struct file *file, struct file_lock *flock) 
		rc = 1;

	}



	mutex_unlock(&cinode->lock_mutex);

	up_read(&cinode->lock_sem);

	return rc;

}
@@ -884,14 +884,14 @@ cifs_posix_lock_set(struct file *file, struct file_lock *flock) 
		return rc;



try_again:

	mutex_lock(&cinode->lock_mutex);

	down_write(&cinode->lock_sem);

	if (!cinode->can_cache_brlcks) {

		mutex_unlock(&cinode->lock_mutex);

		up_write(&cinode->lock_sem);

		return rc;

	}



	rc = posix_lock_file(file, flock, NULL);

	mutex_unlock(&cinode->lock_mutex);

	up_write(&cinode->lock_sem);

	if (rc == FILE_LOCK_DEFERRED) {

		rc = wait_event_interruptible(flock->fl_wait, !flock->fl_next);

		if (!rc)
@@ -918,9 +918,10 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile) 
	xid = get_xid();

	tcon = tlink_tcon(cfile->tlink);



	mutex_lock(&cinode->lock_mutex);

	/* we are going to update can_cache_brlcks here - need a write access */

	down_write(&cinode->lock_sem);

	if (!cinode->can_cache_brlcks) {

		mutex_unlock(&cinode->lock_mutex);

		up_write(&cinode->lock_sem);

		free_xid(xid);

		return rc;

	}
@@ -931,7 +932,7 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile) 
	 */

	max_buf = tcon->ses->server->maxBuf;

	if (!max_buf) {

		mutex_unlock(&cinode->lock_mutex);

		up_write(&cinode->lock_sem);

		free_xid(xid);

		return -EINVAL;

	}
@@ -940,7 +941,7 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile) 
						sizeof(LOCKING_ANDX_RANGE);

	buf = kzalloc(max_num * sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);

	if (!buf) {

		mutex_unlock(&cinode->lock_mutex);

		up_write(&cinode->lock_sem);

		free_xid(xid);

		return -ENOMEM;

	}
@@ -978,7 +979,7 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile) 
	}



	cinode->can_cache_brlcks = false;

	mutex_unlock(&cinode->lock_mutex);

	up_write(&cinode->lock_sem);



	kfree(buf);

	free_xid(xid);
@@ -1013,9 +1014,10 @@ cifs_push_posix_locks(struct cifsFileInfo *cfile) 


	xid = get_xid();



	mutex_lock(&cinode->lock_mutex);

	/* we are going to update can_cache_brlcks here - need a write access */

	down_write(&cinode->lock_sem);

	if (!cinode->can_cache_brlcks) {

		mutex_unlock(&cinode->lock_mutex);

		up_write(&cinode->lock_sem);

		free_xid(xid);

		return rc;

	}
@@ -1031,7 +1033,7 @@ cifs_push_posix_locks(struct cifsFileInfo *cfile) 


	/*

	 * Allocating count locks is enough because no FL_POSIX locks can be

	 * added to the list while we are holding cinode->lock_mutex that

	 * added to the list while we are holding cinode->lock_sem that

	 * protects locking operations of this inode.

	 */

	for (; i < count; i++) {
@@ -1086,7 +1088,7 @@ cifs_push_posix_locks(struct cifsFileInfo *cfile) 


out:

	cinode->can_cache_brlcks = false;

	mutex_unlock(&cinode->lock_mutex);

	up_write(&cinode->lock_sem);



	free_xid(xid);

	return rc;
@@ -1278,7 +1280,7 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, 
	if (!buf)

		return -ENOMEM;



	mutex_lock(&cinode->lock_mutex);

	down_write(&cinode->lock_sem);

	for (i = 0; i < 2; i++) {

		cur = buf;

		num = 0;
@@ -1348,7 +1350,7 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, 
		}

	}



	mutex_unlock(&cinode->lock_mutex);

	up_write(&cinode->lock_sem);

	kfree(buf);

	return rc;

}

fs/cifs/smb2file.c

+8 −7
Original line number Diff line number Diff line
@@ -135,7 +135,7 @@ smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, 


	cur = buf;



	mutex_lock(&cinode->lock_mutex);

	down_write(&cinode->lock_sem);

	list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {

		if (flock->fl_start > li->offset ||

		    (flock->fl_start + length) <
@@ -196,7 +196,7 @@ smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, 
		} else

			cifs_free_llist(&tmp_llist);

	}

	mutex_unlock(&cinode->lock_mutex);

	up_write(&cinode->lock_sem);



	kfree(buf);

	return rc;
@@ -253,9 +253,10 @@ smb2_push_mandatory_locks(struct cifsFileInfo *cfile) 
	struct cifs_fid_locks *fdlocks;



	xid = get_xid();

	mutex_lock(&cinode->lock_mutex);

	/* we are going to update can_cache_brlcks here - need a write access */

	down_write(&cinode->lock_sem);

	if (!cinode->can_cache_brlcks) {

		mutex_unlock(&cinode->lock_mutex);

		up_write(&cinode->lock_sem);

		free_xid(xid);

		return rc;

	}
@@ -266,7 +267,7 @@ smb2_push_mandatory_locks(struct cifsFileInfo *cfile) 
	 */

	max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;

	if (!max_buf) {

		mutex_unlock(&cinode->lock_mutex);

		up_write(&cinode->lock_sem);

		free_xid(xid);

		return -EINVAL;

	}
@@ -274,7 +275,7 @@ smb2_push_mandatory_locks(struct cifsFileInfo *cfile) 
	max_num = max_buf / sizeof(struct smb2_lock_element);

	buf = kzalloc(max_num * sizeof(struct smb2_lock_element), GFP_KERNEL);

	if (!buf) {

		mutex_unlock(&cinode->lock_mutex);

		up_write(&cinode->lock_sem);

		free_xid(xid);

		return -ENOMEM;

	}
@@ -288,7 +289,7 @@ smb2_push_mandatory_locks(struct cifsFileInfo *cfile) 
	cinode->can_cache_brlcks = false;

	kfree(buf);



	mutex_unlock(&cinode->lock_mutex);

	up_write(&cinode->lock_sem);

	free_xid(xid);

	return rc;

}