From 69886e676e89534953b12df77382504a7731f7bb Mon Sep 17 00:00:00 2001 From: Richard Weinberger Date: Fri, 27 Feb 2015 22:55:20 +0100 Subject: [PATCH] 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 --- fs/hostfs/hostfs_kern.c | 13 +++++++------ 1 file 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 @@ static int hostfs_file_open(struct inode *ino, struct file *file) 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 @@ static int hostfs_file_open(struct inode *ino, struct file *file) 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; }