Add the concept of mount points to Mini-OS. A mount point is a path
associated with a device pointer and an open() callback. A mount point
can be either a file (e.g. "/dev/mem") or a directory ("/var/log").
This allows to replace the special casing in the generic open()
handling with a generic mount point handling.
Prepare the open() callbacks to support creating new files by adding a
mode parameter.
Additionally add a close() prototype to include/lib.h, as it is missing
today.
Signed-off-by: Juergen Gross <jgr...@suse.com>
Reviewed-by: Samuel Thibault <samuel.thiba...@ens-lyon.org>
---
V2:
- pass path below mount point to open callbacks (Samuel Thibault)
---
include/lib.h | 9 ++++++
lib/sys.c | 80 +++++++++++++++++++++++++++++++++++++++------------
2 files changed, 70 insertions(+), 19 deletions(-)
diff --git a/include/lib.h b/include/lib.h
index bec99646..36d94ec4 100644
--- a/include/lib.h
+++ b/include/lib.h
@@ -187,6 +187,13 @@ struct file_ops {
bool (*select_wr)(struct file *file);
};
+struct mount_point {
+ const char *path;
+ int (*open)(struct mount_point *mnt, const char *pathname, int flags,
+ mode_t mode);
+ void *dev;
+};
+
unsigned int alloc_file_type(const struct file_ops *ops);
off_t lseek_default(struct file *file, off_t offset, int whence);
@@ -198,6 +205,8 @@ int alloc_fd(unsigned int type);
void close_all_files(void);
extern struct thread *main_thread;
void sparse(unsigned long data, size_t size);
+
+int close(int fd);
#endif
#endif /* _LIB_H_ */
diff --git a/lib/sys.c b/lib/sys.c
index 8f8a3de2..2f33c937 100644
--- a/lib/sys.c
+++ b/lib/sys.c
@@ -263,11 +263,6 @@ char *getcwd(char *buf, size_t size)
return buf;
}
-#define LOG_PATH "/var/log/"
-#define SAVE_PATH "/var/lib/xen"
-#define SAVE_CONSOLE 1
-#define RESTORE_CONSOLE 2
-
int mkdir(const char *pathname, mode_t mode)
{
errno = EIO;
@@ -286,18 +281,30 @@ int posix_openpt(int flags)
return fd;
}
+static int open_pt(struct mount_point *mnt, const char *pathname, int flags,
+ mode_t mode)
+{
+ return posix_openpt(flags);
+}
+
int open_savefile(const char *path, int save)
{
int fd;
char nodename[64];
- snprintf(nodename, sizeof(nodename), "device/console/%d", save ?
SAVE_CONSOLE : RESTORE_CONSOLE);
+ snprintf(nodename, sizeof(nodename), "device/console/%d", save ? 1 : 2);
fd = open_consfront(nodename);
printk("fd(%d) = open_savefile\n", fd);
return fd;
}
+
+static int open_save(struct mount_point *mnt, const char *pathname, int flags,
+ mode_t mode)
+{
+ return open_savefile(pathname, flags & O_WRONLY);
+}
#else
int posix_openpt(int flags)
{
@@ -311,24 +318,59 @@ int open_savefile(const char *path, int save)
}
#endif
-int open(const char *pathname, int flags, ...)
+static int open_log(struct mount_point *mnt, const char *pathname, int flags,
+ mode_t mode)
{
int fd;
+
/* Ugly, but fine. */
- if (!strncmp(pathname,LOG_PATH,strlen(LOG_PATH))) {
- fd = alloc_fd(FTYPE_CONSOLE);
- printk("open(%s) -> %d\n", pathname, fd);
- return fd;
+ fd = alloc_fd(FTYPE_CONSOLE);
+ printk("open(%s%s) -> %d\n", mnt->path, pathname, fd);
+ return fd;
+}
+
+static int open_mem(struct mount_point *mnt, const char *pathname, int flags,
+ mode_t mode)
+{
+ int fd;
+
+ fd = alloc_fd(FTYPE_MEM);
+ printk("open(%s%s) -> %d\n", mnt->path, pathname, fd);
+ return fd;
+}
+
+static struct mount_point mount_points[] = {
+ { .path = "/var/log", .open = open_log, .dev = NULL },
+ { .path = "/dev/mem", .open = open_mem, .dev = NULL },
+#ifdef CONFIG_CONSFRONT
+ { .path = "/dev/ptmx", .open = open_pt, .dev = NULL },
+ { .path = "/var/lib/xen", .open = open_save, .dev = NULL },
+#endif
+};
+
+int open(const char *pathname, int flags, ...)
+{
+ unsigned int m, mlen;
+ struct mount_point *mnt;
+ mode_t mode = 0;
+ va_list ap;
+
+ if ( flags & O_CREAT )
+ {
+ va_start(ap, flags);
+ mode = va_arg(ap, mode_t);
+ va_end(ap);
}
- if (!strncmp(pathname, "/dev/mem", strlen("/dev/mem"))) {
- fd = alloc_fd(FTYPE_MEM);
- printk("open(/dev/mem) -> %d\n", fd);
- return fd;
+
+ for ( m = 0; m < ARRAY_SIZE(mount_points); m++ )
+ {
+ mnt = mount_points + m;
+ mlen = strlen(mnt->path);
+ if ( !strncmp(pathname, mnt->path, mlen) &&
+ (pathname[mlen] == '/' || pathname[mlen] == 0) )
+ return mnt->open(mnt, pathname + mlen, flags, mode);
}
- if (!strncmp(pathname, "/dev/ptmx", strlen("/dev/ptmx")))
- return posix_openpt(flags);
- if (!strncmp(pathname,SAVE_PATH,strlen(SAVE_PATH)))
- return open_savefile(pathname, flags & O_WRONLY);
+
errno = EIO;
return -1;
}
--
2.35.3
