Second Extended Filesystem (ext2) and other improvements (#33)

[lunaix-os.git] / lunaix-os / kernel / fs / mount.c

diff --git a/lunaix-os/kernel/fs/mount.c b/lunaix-os/kernel/fs/mount.c
index ff8d46b5bb91a3a1ca8e32e9bdf28a7c26087592..c5b7344be4f2723f45961f53705a10c395f67fe0 100644 (file)
--- a/lunaix-os/kernel/fs/mount.c
+++ b/lunaix-os/kernel/fs/mount.c
@@ -1,9 +1,14 @@
 #include <lunaix/foptions.h>
-#include <lunaix/fs.h>
+#include <lunaix/fs/api.h>
 #include <lunaix/mm/valloc.h>
 #include <lunaix/process.h>
+#include <lunaix/spike.h>
+#include <lunaix/syscall_utils.h>
+#include <lunaix/syslog.h>
 #include <lunaix/types.h>
 
+LOG_MODULE("fs")
+
 struct llist_header all_mnts = { .next = &all_mnts, .prev = &all_mnts };
 
 struct v_mount*
@@ -18,22 +23,37 @@ vfs_create_mount(struct v_mount* parent, struct v_dnode* mnt_point)
     llist_append(&all_mnts, &mnt->list);
     mutex_init(&mnt->lock);
 
-    mnt_mkbusy(parent);
     mnt->parent = parent;
     mnt->mnt_point = mnt_point;
-    mnt->super_block = mnt_point->super_block;
+    vfs_vmnt_assign_sb(mnt, mnt_point->super_block);
 
     if (parent) {
+        mnt_mkbusy(parent);
         mutex_lock(&mnt->parent->lock);
         llist_append(&parent->submnts, &mnt->sibmnts);
         mutex_unlock(&mnt->parent->lock);
     }
-
+    
     atomic_fetch_add(&mnt_point->ref_count, 1);
 
     return mnt;
 }
 
+void
+__vfs_release_vmnt(struct v_mount* mnt)
+{
+    assert(llist_empty(&mnt->submnts));
+
+    if (mnt->parent) {
+        mnt_chillax(mnt->parent);
+    }
+
+    llist_delete(&mnt->sibmnts);
+    llist_delete(&mnt->list);
+    atomic_fetch_sub(&mnt->mnt_point->ref_count, 1);
+    vfree(mnt);
+}
+
 int
 __vfs_do_unmount(struct v_mount* mnt)
 {
@@ -44,9 +64,6 @@ __vfs_do_unmount(struct v_mount* mnt)
         return errno;
     }
 
-    llist_delete(&mnt->list);
-    llist_delete(&mnt->sibmnts);
-
     // detached the inodes from cache, and let lru policy to recycle them
     for (size_t i = 0; i < VFS_HASHTABLE_SIZE; i++) {
         struct hbucket* bucket = &sb->i_cache[i];
@@ -56,11 +73,10 @@ __vfs_do_unmount(struct v_mount* mnt)
         bucket->head->pprev = 0;
     }
 
-    mnt_chillax(mnt->parent);
+    mnt->mnt_point->mnt = mnt->parent;
 
     vfs_sb_free(sb);
-    vfs_d_free(mnt->mnt_point);
-    vfree(mnt);
+    __vfs_release_vmnt(mnt);
 
     return errno;
 }
@@ -68,30 +84,23 @@ __vfs_do_unmount(struct v_mount* mnt)
 void
 mnt_mkbusy(struct v_mount* mnt)
 {
-    while (mnt) {
-        mutex_lock(&mnt->lock);
-        mnt->busy_counter++;
-        mutex_unlock(&mnt->lock);
-
-        mnt = mnt->parent;
-    }
+    mutex_lock(&mnt->lock);
+    mnt->busy_counter++;
+    mutex_unlock(&mnt->lock);
 }
 
 void
 mnt_chillax(struct v_mount* mnt)
 {
-    while (mnt) {
-        mutex_lock(&mnt->lock);
-        mnt->busy_counter--;
-        mutex_unlock(&mnt->lock);
-
-        mnt = mnt->parent;
-    }
+    mutex_lock(&mnt->lock);
+    mnt->busy_counter--;
+    mutex_unlock(&mnt->lock);
 }
 
 int
 vfs_mount_root(const char* fs_name, struct device* device)
 {
+    extern struct v_dnode* vfs_sysroot;
     int errno = 0;
     if (vfs_sysroot->mnt && (errno = vfs_unmount_at(vfs_sysroot))) {
         return errno;
@@ -135,7 +144,11 @@ vfs_mount_at(const char* fs_name,
              struct v_dnode* mnt_point,
              int options)
 {
-    if (mnt_point->inode && !(mnt_point->inode->itype & VFS_IFDIR)) {
+    if (device && device->dev_type != DEV_IFVOL) {
+        return ENOTBLK;
+    }
+
+    if (mnt_point->inode && !check_directory_node(mnt_point->inode)) {
         return ENOTDIR;
     }
 
@@ -144,31 +157,55 @@ vfs_mount_at(const char* fs_name,
         return ENODEV;
     }
 
-    struct v_mount* parent_mnt = mnt_point->mnt;
-    struct v_superblock *sb = vfs_sb_alloc(), *old_sb = mnt_point->super_block;
-    sb->dev = device;
-    mnt_point->super_block = sb;
+    if ((fs->types & FSTYPE_ROFS)) {
+        options |= MNT_RO;
+    }
+
+    if (!(fs->types & FSTYPE_PSEUDO) && !device) {
+        return ENODEV;
+    }
 
     int errno = 0;
-    if (!(errno = fs->mount(sb, mnt_point))) {
-        sb->fs = fs;
-        sb->root = mnt_point;
+    char* dev_name = "sys";
+    struct v_mount* parent_mnt = mnt_point->mnt;
+    struct v_superblock *sb = vfs_sb_alloc(), 
+                        *old_sb = mnt_point->super_block;
 
-        if (!(mnt_point->mnt = vfs_create_mount(parent_mnt, mnt_point))) {
-            errno = ENOMEM;
-            goto cleanup;
-        }
+    if (device) {
+        dev_name = device->name_val;
+    }
+
+    // prepare v_superblock for fs::mount invoke
+    sb->dev = device;
+    sb->fs = fs;
+    sb->root = mnt_point;
+    vfs_d_assign_sb(mnt_point, sb);
 
-        mnt_point->mnt->flags = options;
+    if (!(mnt_point->mnt = vfs_create_mount(parent_mnt, mnt_point))) {
+        errno = ENOMEM;
+        goto cleanup;
+    }
+
+    mnt_point->mnt->flags = options;
+    if (!(errno = fs->mount(sb, mnt_point))) {
+        kprintf("mount: dev=%s, fs=%s, mode=%d", dev_name, fs_name, options);
     } else {
         goto cleanup;
     }
 
+    vfs_sb_free(old_sb);
     return errno;
 
 cleanup:
-    mnt_point->super_block = old_sb;
+    ERROR("failed mount: dev=%s, fs=%s, mode=%d, err=%d",
+          dev_name,
+          fs_name,
+          options,
+          errno);
+    vfs_d_assign_sb(mnt_point, old_sb);
     vfs_sb_free(sb);
+    __vfs_release_vmnt(mnt_point->mnt);
+
     return errno;
 }
 
@@ -216,12 +253,11 @@ __DEFINE_LXSYSCALL4(int,
                     int,
                     options)
 {
-    struct v_dnode *dev, *mnt;
+    struct v_dnode *dev = NULL, *mnt = NULL;
     int errno = 0;
 
-    if ((errno = vfs_walk(__current->cwd, source, &dev, NULL, 0))) {
-        goto done;
-    }
+    // It is fine if source is not exist, as some mounting don't require it
+    vfs_walk(__current->cwd, source, &dev, NULL, 0);
 
     if ((errno = vfs_walk(__current->cwd, target, &mnt, NULL, 0))) {
         goto done;
@@ -232,13 +268,21 @@ __DEFINE_LXSYSCALL4(int,
         goto done;
     }
 
+    if (mnt->mnt->mnt_point == mnt) {
+        errno = EBUSY;
+        goto done;
+    }
+
     // By our convention.
     // XXX could we do better?
-    struct device* device = (struct device*)dev->inode->data;
+    struct device* device = NULL;
 
-    if (!(dev->inode->itype & VFS_IFVOLDEV) || !device) {
-        errno = ENOTDEV;
-        goto done;
+    if (dev) {
+        if (!check_voldev_node(dev->inode)) {
+            errno = ENOTDEV;
+            goto done;
+        }
+        device = (struct device*)dev->inode->data;
     }
 
     errno = vfs_mount_at(fstype, device, mnt, options);