diff options
| -rw-r--r-- | fs/hostfs/hostfs.h | 1 | ||||
| -rw-r--r-- | fs/hostfs/hostfs_kern.c | 43 | ||||
| -rw-r--r-- | fs/hostfs/hostfs_user.c | 5 |
3 files changed, 37 insertions, 12 deletions
diff --git a/fs/hostfs/hostfs.h b/fs/hostfs/hostfs.h index ea87e22..6bbd75c 100644 --- a/fs/hostfs/hostfs.h +++ b/fs/hostfs/hostfs.h @@ -74,6 +74,7 @@ extern void *open_dir(char *path, int *err_out); extern char *read_dir(void *stream, unsigned long long *pos, unsigned long long *ino_out, int *len_out); extern void close_file(void *stream); +extern int replace_file(int oldfd, int fd); extern void close_dir(void *stream); extern int read_file(int fd, unsigned long long *offset, char *buf, int len); extern int write_file(int fd, unsigned long long *offset, const char *buf, diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c index 8130ce9..dd1e555 100644 --- a/fs/hostfs/hostfs_kern.c +++ b/fs/hostfs/hostfs_kern.c @@ -302,27 +302,22 @@ int hostfs_readdir(struct file *file, void *ent, filldir_t filldir) int hostfs_file_open(struct inode *ino, struct file *file) { + static DEFINE_MUTEX(open_mutex); char *name; fmode_t mode = 0; + int err; int r = 0, w = 0, fd; mode = file->f_mode & (FMODE_READ | FMODE_WRITE); if ((mode & HOSTFS_I(ino)->mode) == mode) return 0; - /* - * The file may already have been opened, but with the wrong access, - * so this resets things and reopens the file with the new access. - */ - if (HOSTFS_I(ino)->fd != -1) { - close_file(&HOSTFS_I(ino)->fd); - HOSTFS_I(ino)->fd = -1; - } + mode |= HOSTFS_I(ino)->mode; - HOSTFS_I(ino)->mode |= mode; - if (HOSTFS_I(ino)->mode & FMODE_READ) +retry: + if (mode & FMODE_READ) r = 1; - if (HOSTFS_I(ino)->mode & FMODE_WRITE) + if (mode & FMODE_WRITE) w = 1; if (w) r = 1; @@ -335,7 +330,31 @@ int hostfs_file_open(struct inode *ino, struct file *file) __putname(name); if (fd < 0) return fd; - FILE_HOSTFS_I(file)->fd = fd; + + mutex_lock(&open_mutex); + /* somebody else had handled it first? */ + if ((mode & HOSTFS_I(ino)->mode) == mode) { + mutex_unlock(&open_mutex); + return 0; + } + if ((mode | HOSTFS_I(ino)->mode) != mode) { + mode |= HOSTFS_I(ino)->mode; + mutex_unlock(&open_mutex); + close_file(&fd); + goto retry; + } + if (HOSTFS_I(ino)->fd == -1) { + HOSTFS_I(ino)->fd = fd; + } else { + err = replace_file(fd, HOSTFS_I(ino)->fd); + close_file(&fd); + if (err < 0) { + mutex_unlock(&open_mutex); + return err; + } + } + HOSTFS_I(ino)->mode = mode; + mutex_unlock(&open_mutex); return 0; } diff --git a/fs/hostfs/hostfs_user.c b/fs/hostfs/hostfs_user.c index 91ebfce..6777aa0 100644 --- a/fs/hostfs/hostfs_user.c +++ b/fs/hostfs/hostfs_user.c @@ -160,6 +160,11 @@ int fsync_file(int fd, int datasync) return 0; } +int replace_file(int oldfd, int fd) +{ + return dup2(oldfd, fd); +} + void close_file(void *stream) { close(*((int *) stream)); |