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authorRichard Weinberger <richard@nod.at>2015-02-27 22:55:20 +0100
committerRichard Weinberger <richard@nod.at>2015-03-26 23:27:47 +0100
commit69886e676e89534953b12df77382504a7731f7bb (patch)
tree2d2f096782861f19e28880a9d209269ac8aad371 /fs/hostfs
parentbc465aa9d045feb0e13b4a8f32cc33c1943f62d6 (diff)
downloadlinux-69886e676e89534953b12df77382504a7731f7bb.tar.gz
hostfs: hostfs_file_open: Switch to data locking model
Instead of serializing hostfs_file_open() we can use
a per inode mutex to protect ->mode.

Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'fs/hostfs')
-rw-r--r--fs/hostfs/hostfs_kern.c13
1 files changed, 7 insertions, 6 deletions
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index fd62cae0fdcb..104d58d2c78c 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -24,6 +24,7 @@ struct hostfs_inode_info {
 	int fd;
 	fmode_t mode;
 	struct inode vfs_inode;
+	struct mutex open_mutex;
 };
 
 static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode)
@@ -225,6 +226,7 @@ static struct inode *hostfs_alloc_inode(struct super_block *sb)
 	hi->fd = -1;
 	hi->mode = 0;
 	inode_init_once(&hi->vfs_inode);
+	mutex_init(&hi->open_mutex);
 	return &hi->vfs_inode;
 }
 
@@ -295,7 +297,6 @@ static int hostfs_readdir(struct file *file, struct dir_context *ctx)
 
 static int hostfs_file_open(struct inode *ino, struct file *file)
 {
-	static DEFINE_MUTEX(open_mutex);
 	char *name;
 	fmode_t mode = 0;
 	int err;
@@ -324,15 +325,15 @@ retry:
 	if (fd < 0)
 		return fd;
 
-	mutex_lock(&open_mutex);
+	mutex_lock(&HOSTFS_I(ino)->open_mutex);
 	/* somebody else had handled it first? */
 	if ((mode & HOSTFS_I(ino)->mode) == mode) {
-		mutex_unlock(&open_mutex);
+		mutex_unlock(&HOSTFS_I(ino)->open_mutex);
 		return 0;
 	}
 	if ((mode | HOSTFS_I(ino)->mode) != mode) {
 		mode |= HOSTFS_I(ino)->mode;
-		mutex_unlock(&open_mutex);
+		mutex_unlock(&HOSTFS_I(ino)->open_mutex);
 		close_file(&fd);
 		goto retry;
 	}
@@ -342,12 +343,12 @@ retry:
 		err = replace_file(fd, HOSTFS_I(ino)->fd);
 		close_file(&fd);
 		if (err < 0) {
-			mutex_unlock(&open_mutex);
+			mutex_unlock(&HOSTFS_I(ino)->open_mutex);
 			return err;
 		}
 	}
 	HOSTFS_I(ino)->mode = mode;
-	mutex_unlock(&open_mutex);
+	mutex_unlock(&HOSTFS_I(ino)->open_mutex);
 
 	return 0;
 }