From: Sage Weil <sage@inktank.com>
Date: Fri, 19 Apr 2013 17:07:11 +0000 (-0700)
Subject: fuse: add exclusion between reads and invalidate
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=55f2cdc6d2cd9d3816c2ace1c374750b6e0ce17e;p=ceph-client.git

fuse: add exclusion between reads and invalidate

This blocks new reads from starting if an invalidate is in progress...

Signed-off-by: Sage Weil <sage@inktank.com>
---

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index f3ab824fa302..a0dd4f896d49 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -704,6 +704,7 @@ static ssize_t fuse_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 {
 	struct inode *inode = iocb->ki_filp->f_mapping->host;
 	struct fuse_conn *fc = get_fuse_conn(inode);
+	int ret;
 
 	/*
 	 * In auto invalidate mode, always update attributes on read.
@@ -717,8 +718,10 @@ static ssize_t fuse_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 		if (err)
 			return err;
 	}
-
-	return generic_file_aio_read(iocb, iov, nr_segs, pos);
+	mutex_lock(&fc->invalidate_mutex);
+	ret = generic_file_aio_read(iocb, iov, nr_segs, pos);
+	mutex_unlock(&fc->invalidate_mutex);
+	return ret;
 }
 
 static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff,
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index e105a53fc72d..e4c8d11056b2 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -328,6 +328,7 @@ struct fuse_conn {
 
 	/** Mutex protecting against directory alias creation */
 	struct mutex inst_mutex;
+	struct mutex invalidate_mutex;
 
 	/** Refcount */
 	atomic_t count;
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 73ca6b72beaf..40dae2de1e10 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -314,6 +314,7 @@ int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 	struct inode *inode;
 	pgoff_t pg_start;
 	pgoff_t pg_end;
+	struct fuse_conn *fc;
 
 	inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
 	if (!inode)
@@ -321,6 +322,8 @@ int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 
 	fuse_invalidate_attr(inode);
 	if (offset >= 0) {
+		fc = get_fuse_conn(inode);
+		mutex_lock(&fc->invalidate_mutex);
 		pg_start = offset >> PAGE_CACHE_SHIFT;
 		if (len <= 0)
 			pg_end = -1;
@@ -328,6 +331,7 @@ int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 			pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
 		invalidate_inode_pages2_range(inode->i_mapping,
 					      pg_start, pg_end);
+		mutex_unlock(&fc->invalidate_mutex);
 	}
 	iput(inode);
 	return 0;
@@ -562,6 +566,7 @@ void fuse_conn_init(struct fuse_conn *fc)
 	memset(fc, 0, sizeof(*fc));
 	spin_lock_init(&fc->lock);
 	mutex_init(&fc->inst_mutex);
+	mutex_init(&fc->invalidate_mutex);
 	init_rwsem(&fc->killsb);
 	atomic_set(&fc->count, 1);
 	init_waitqueue_head(&fc->waitq);