starting to create sysfs

5 files changed, 180 insertions, 2 deletions

diff --git a/fs/ext2.c b/fs/ext2.c
index 659edda..b518bd9 100644
--- a/fs/ext2.c
+++ b/fs/ext2.c
@@ -1,6 +1,7 @@
 #include <stdbool.h>
 #include <stdint.h>
 
+#include "mount.h"
 #include "kernel.h"
 #include "ext2.h"
 
@@ -303,3 +304,27 @@ int ext2_read_dir(uint32_t ext2_start_addr, int inode_nr, fs_dirent *dirs, uint3
     }
     return 0;
 }
+
+/* mount interface */
+
+fd ext2_mount_file_open(mount *m,char *path)
+{
+    return fd_from_path(path);
+}
+
+int ext2_mount_read_dir(mount *m,char *path, fs_dirent *dirs, uint32_t *pos)
+{
+    uint32_t inode= ext2_filename_to_inode(VMEM_EXT2_RAMIMAGE,path); 
+    return ext2_read_dir(m->data, inode, dirs, pos);
+}
+
+void ext2_mount(char *path)
+{
+    mount m;
+    m.type=MOUNT_TYPE_EXT2;
+    memcpy(m.path,path,strlen(path)+1);
+    m.mount_file_open=ext2_mount_file_open;
+    m.mount_read_dir=ext2_mount_read_dir;
+    m.data=VMEM_EXT2_RAMIMAGE;
+    mount_add(m);
+}
diff --git a/fs/ext2.h b/fs/ext2.h
index efa045f..3c53350 100644
--- a/fs/ext2.h
+++ b/fs/ext2.h
@@ -33,3 +33,6 @@ uint32_t ext2_filename_to_inode(uint32_t ext2_start_addr, char *path);
 
 /** get address of first byte of given block for given inode number */
 uint32_t ext2_inode_blockstart(uint32_t ext2_start_addr,uint32_t inode_nr,uint32_t block);
+
+/** mount */
+void ext2_mount(char *path);
diff --git a/fs/fd.h b/fs/fd.h
index 429387b..a51a0f3 100644
--- a/fs/fd.h
+++ b/fs/fd.h
@@ -26,7 +26,8 @@ typedef struct
 
 enum FD_TYPE{
     FD_TYPE_FIFO_BUFFERED=1,
-    FD_TYPE_EXT2_FILE=2
+    FD_TYPE_EXT2_FILE=2,
+    FD_TYPE_EXT2_DIR=3
 };
 
 typedef struct fd_struct
@@ -47,5 +48,5 @@ bool    fd_close(fd*);
 
 fd fd_from_fifo(fifo* f);
 fd fd_from_path(char *path);
-
+//fd fd_from_sysfs(void(*g)(void (*f)(char *fmt, ...)));
 #endif
diff --git a/fs/mount.c b/fs/mount.c
new file mode 100644
index 0000000..a7cd949
--- /dev/null
+++ b/fs/mount.c
@@ -0,0 +1,96 @@
+#include <stddef.h>
+
+#include "kernel.h"
+#include "mount.h"
+
+#include "log.h"
+
+#include "lib/string/string.h"
+// temporary
+#include "fd.h"
+
+static mount mounts[MAX_MOUNTS];
+static uint32_t mounts_count=0;
+
+char *mount_type_to_str(uint32_t t)
+{
+    switch(t)
+    {
+	case MOUNT_TYPE_EXT2:  return "EXT2";
+	case MOUNT_TYPE_PIPES: return "PIPES";
+	case MOUNT_TYPE_SYS:   return "SYS";
+    }
+    return "UNKNOWN";
+}
+
+void mount_add(mount mnt)
+{
+    if(mounts_count==MAX_MOUNTS)kpanic("maxium number of mounts exceeded. increase MAX_MOUNTS in kernel.h and recomplie kernel.");
+    mounts[mounts_count++]=mnt;
+    klog("mounted %s",mnt.path);
+}
+
+void mount_dump()
+{
+    for(int i=0;i<mounts_count;i++)
+    {
+	mount *m=&mounts[i];
+	klog("%s mounted at: %s ",mount_type_to_str(m->type),m->path);
+    }
+}
+
+static uint32_t check_match(char *p1, char *p2)
+{
+    uint32_t c=0;
+    while(1)
+    {
+	if(*p1==0||*p2==0||*p1!=*p2)return c;
+	c++;
+	p1++;
+	p2++;
+    }
+}
+
+/** 
+ *  Find the mountpoint correspoding with the given path and return in _mnt_ parameter.
+ *  The return value points to the input path with chopped of prefix indicating the mount itself. 
+ *  returns 0 if mount not found.
+ */
+static char* get_mount_for_path(char *path,mount *mnt)
+{
+    if(path[0]!='/')kpanic("this works only for absolute paths!");
+
+    uint32_t best=0;
+    uint32_t best_len=0;
+    
+    for(int i=0;i<mounts_count;i++)
+    {
+	mount *m=&mounts[i];
+	uint32_t len=check_match(path,m->path);
+
+	if(len>best_len&&len==strlen(m->path))
+	{
+	    best=i;
+	    best_len=len;
+	}
+
+    }
+    if(best_len==0)return 0;
+    *mnt=mounts[best];
+    return path+best_len-1;
+}
+
+fd mount_file_open(char *path)
+{
+    mount m;
+    char *p=get_mount_for_path(path,&m);
+    klog("%s in %s",p,m.path);
+    return m.mount_file_open(&m,p);
+}
+
+int mount_read_dir (char *path, fs_dirent *dirs, uint32_t *pos)
+{
+    mount m;
+    char *p=get_mount_for_path(path,&m);
+    return m.mount_read_dir(&m,p,dirs,pos);
+}
diff --git a/fs/mount.h b/fs/mount.h
new file mode 100644
index 0000000..4e61c28
--- /dev/null
+++ b/fs/mount.h
@@ -0,0 +1,53 @@
+/**
+ * @file
+ * Simple mount point manager
+ * ==========================
+ *
+ * Add up to MAX_MOUNTS (as defined in kernel.h) mounts and use
+ * mount_file_open() and mount_read_dir() to transparently 
+ * be dispatch the underlying commands to them based on the supplied paths.
+ *
+ * Mount directories should exist on root direcotry '/'
+ */
+
+#ifndef MOUNT_H
+#define MOUNT_H
+
+#include <stdint.h>
+#include "interface/fs.h" // fs_dirent for read_dir
+#include "fd.h" // file descriptor returned by open
+
+/** the possible values for mount_struct.type */
+enum MOUNT_TYPE{
+    MOUNT_TYPE_EXT2	=	1,
+    MOUNT_TYPE_PIPES	=	2,
+    MOUNT_TYPE_SYS	=	3
+};
+
+/** struct telling all we need about a single mountpoint */
+typedef struct mount_struct
+{
+    uint32_t type;    // MOUNT_TYPE
+
+    char path[256];   // where are we mounted (provide leading and trailing slash!)
+
+    fd   (*mount_file_open)(struct mount_struct*, char *path);
+    int  (*mount_read_dir) (struct mount_struct*, char *path, fs_dirent *dirs, uint32_t *pos);
+
+    void *data; //opaque data
+
+}mount;
+
+/** dumps mount info to klog */
+void mount_dump();
+
+/** adds a new mountpoints */
+void mount_add(mount mnt);
+
+/** dispatchers to according mount points */
+fd mount_file_open(char *path);
+
+/** TODO: should use fd number instead of PATH on each call*/
+int  mount_read_dir (char *path, fs_dirent *dirs, uint32_t *pos);
+
+#endif