feat: vfs support sdcard hotplug

close: #I44WH1
Signed-off-by: mucor <mucorwang@gmail.com>

drivers/block/disk/src/disk.c

@@ -1422,10 +1422,13 @@ DISK_FIND_ERROR:
 
 INT32 los_disk_deinit(INT32 diskID)
 {
+    int ret;
     los_disk *disk = get_disk(diskID);
     if (disk == NULL) {
         return -EINVAL;
     }
+    ret = ForceUmountDev(disk->dev);
+    PRINTK("warning: %s lost, force umount ret = %d\n", disk->disk_name, ret);
 
     DISK_LOCK(&disk->disk_mutex);
 

fs/include/fs/mount.h

@@ -45,6 +45,7 @@ struct Mount {
     const struct MountOps *ops;        /* operations of mount */
     struct Vnode *vnodeBeCovered;      /* vnode we mounted on */
     struct Vnode *vnodeCovered;        /* syncer vnode */
+    struct Vnode *vnodeDev;            /* dev vnode */
     LIST_HEAD vnodeList;               /* list of vnodes */
     int vnodeSize;                     /* size of vnode list */
     LIST_HEAD activeVnodeList;         /* list of active vnodes */
@@ -70,4 +71,5 @@ typedef int (*foreach_mountpoint_t)(const char *devpoint,
 struct Mount* MountAlloc(struct Vnode* vnode, struct MountOps* mop);
 LIST_HEAD* GetMountList(void);
 int foreach_mountpoint(foreach_mountpoint_t handler, void *arg);
+int ForceUmountDev(struct Vnode *dev);
 #endif

fs/vfs/BUILD.gn

@@ -41,6 +41,7 @@ kernel_module(module_name) {
     "operation/vfs_fallocate64.c",
     "operation/vfs_fcntl.c",
     "operation/vfs_file_mapping.c",
+    "operation/vfs_force_umount.c",
     "operation/vfs_init.c",
     "operation/vfs_other.c",
     "operation/vfs_preadv.c",

fs/vfs/operation/vfs_force_umount.c

@@ -0,0 +1,391 @@
+/*
+ * Copyright (c) 2021-2021 Huawei Device Co., Ltd. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this list of
+ *    conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *    of conditions and the following disclaimer in the documentation and/or other materials
+ *    provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors may be used
+ *    to endorse or promote products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "fs/mount.h"
+#include "fs/dirent_fs.h"
+#include "fs/file.h"
+#include "vnode.h"
+#include "path_cache.h"
+
+/* vnode operations returns EIO */
+static int ErrorVopCreate (struct Vnode *parent, const char *name, int mode, struct Vnode **vnode)
+{
+    return -EIO;
+}
+
+static int ErrorVopLookup (struct Vnode *parent, const char *name, int len, struct Vnode **vnode)
+{
+    return -EIO;
+}
+
+static int ErrorVopOpen (struct Vnode *vnode, int fd, int mode, int flags)
+{
+    return -EIO;
+}
+
+static int ErrorVopClose (struct Vnode *vnode)
+{
+    /* already closed at force umount, do nothing here */
+    return OK;
+}
+
+static int ErrorVopReclaim (struct Vnode *vnode)
+{
+    return -EIO;
+}
+
+static int ErrorVopUnlink (struct Vnode *parent, struct Vnode *vnode, const char *fileName)
+{
+    return -EIO;
+}
+
+static int ErrorVopRmdir (struct Vnode *parent, struct Vnode *vnode, const char *dirName)
+{
+    return -EIO;
+}
+
+static int ErrorVopMkdir (struct Vnode *parent, const char *dirName, mode_t mode, struct Vnode **vnode)
+{
+    return -EIO;
+}
+
+static int ErrorVopReaddir (struct Vnode *vnode, struct fs_dirent_s *dir)
+{
+    return -EIO;
+}
+
+static int ErrorVopOpendir (struct Vnode *vnode, struct fs_dirent_s *dir)
+{
+    return -EIO;
+}
+
+static int ErrorVopRewinddir (struct Vnode *vnode, struct fs_dirent_s *dir)
+{
+    return -EIO;
+}
+
+static int ErrorVopClosedir (struct Vnode *vnode, struct fs_dirent_s *dir)
+{
+    /* already closed at force umount, do nothing here */
+    return OK;
+}
+
+static int ErrorVopGetattr (struct Vnode *vnode, struct stat *st)
+{
+    return -EIO;
+}
+
+static int ErrorVopSetattr (struct Vnode *vnode, struct stat *st)
+{
+    return -EIO;
+}
+
+static int ErrorVopChattr (struct Vnode *vnode, struct IATTR *attr)
+{
+    return -EIO;
+}
+
+static int ErrorVopRename (struct Vnode *src, struct Vnode *dstParent, const char *srcName, const char *dstName)
+{
+    return -EIO;
+}
+
+static int ErrorVopTruncate (struct Vnode *vnode, off_t len)
+{
+    return -EIO;
+}
+
+static int ErrorVopTruncate64 (struct Vnode *vnode, off64_t len)
+{
+    return -EIO;
+}
+
+static int ErrorVopFscheck (struct Vnode *vnode, struct fs_dirent_s *dir)
+{
+    return -EIO;
+}
+
+static int ErrorVopLink (struct Vnode *src, struct Vnode *dstParent, struct Vnode **dst, const char *dstName)
+{
+    return -EIO;
+}
+
+static int ErrorVopSymlink (struct Vnode *parentVnode, struct Vnode **newVnode, const char *path, const char *target)
+{
+    return -EIO;
+}
+
+static ssize_t ErrorVopReadlink (struct Vnode *vnode, char *buffer, size_t bufLen)
+{
+    return -EIO;
+}
+
+static struct VnodeOps g_errorVnodeOps = {
+    .Create = ErrorVopCreate,
+    .Lookup = ErrorVopLookup,
+    .Open = ErrorVopOpen,
+    .Close = ErrorVopClose,
+    .Reclaim = ErrorVopReclaim,
+    .Unlink = ErrorVopUnlink,
+    .Rmdir = ErrorVopRmdir,
+    .Mkdir = ErrorVopMkdir,
+    .Readdir = ErrorVopReaddir,
+    .Opendir = ErrorVopOpendir,
+    .Rewinddir = ErrorVopRewinddir,
+    .Closedir = ErrorVopClosedir,
+    .Getattr = ErrorVopGetattr,
+    .Setattr = ErrorVopSetattr,
+    .Chattr = ErrorVopChattr,
+    .Rename = ErrorVopRename,
+    .Truncate = ErrorVopTruncate,
+    .Truncate64 = ErrorVopTruncate64,
+    .Fscheck = ErrorVopFscheck,
+    .Link = ErrorVopLink,
+    .Symlink = ErrorVopSymlink,
+    .Readlink = ErrorVopReadlink,
+};
+
+/* file operations returns EIO */
+static int ErrorFopOpen (struct file *filep)
+{
+    return -EIO;
+}
+
+static int ErrorFopClose (struct file *filep)
+{
+    /* already closed at force umount, do nothing here */
+    return OK;
+}
+
+static ssize_t ErrorFopRead (struct file *filep, char *buffer, size_t buflen)
+{
+    return -EIO;
+}
+
+static ssize_t ErrorFopWrite (struct file *filep, const char *buffer, size_t buflen)
+{
+    return -EIO;
+}
+
+static off_t ErrorFopSeek (struct file *filep, off_t offset, int whence)
+{
+    return -EIO;
+}
+
+static int ErrorFopIoctl (struct file *filep, int cmd, unsigned long arg)
+{
+    return -EIO;
+}
+
+static int ErrorFopMmap (struct file* filep, struct VmMapRegion *region)
+{
+    return -EIO;
+}
+
+static int ErrorFopPoll (struct file *filep, poll_table *fds)
+{
+    return -EIO;
+}
+
+static int ErrorFopStat (struct file *filep, struct stat* st)
+{
+    return -EIO;
+}
+
+static int ErrorFopFallocate (struct file* filep, int mode, off_t offset, off_t len)
+{
+    return -EIO;
+}
+
+static int ErrorFopFallocate64 (struct file *filep, int mode, off64_t offset, off64_t len)
+{
+    return -EIO;
+}
+
+static int ErrorFopFsync (struct file *filep)
+{
+    return -EIO;
+}
+
+static ssize_t ErrorFopReadpage (struct file *filep, char *buffer, size_t buflen)
+{
+    return -EIO;
+}
+
+static int ErrorFopUnlink (struct Vnode *vnode)
+{
+    return -EIO;
+}
+
+static struct file_operations_vfs g_errorFileOps = {
+    .open = ErrorFopOpen,
+    .close = ErrorFopClose,
+    .read = ErrorFopRead,
+    .write = ErrorFopWrite,
+    .seek = ErrorFopSeek,
+    .ioctl = ErrorFopIoctl,
+    .mmap = ErrorFopMmap,
+    .poll = ErrorFopPoll,
+    .stat = ErrorFopStat,
+    .fallocate = ErrorFopFallocate,
+    .fallocate64 = ErrorFopFallocate64,
+    .fsync = ErrorFopFsync,
+    .readpage = ErrorFopReadpage,
+    .unlink = ErrorFopUnlink,
+};
+
+static struct Mount* GetDevMountPoint(struct Vnode *dev)
+{
+    struct Mount *mnt = NULL;
+    LIST_HEAD *mntList = GetMountList();
+    LOS_DL_LIST_FOR_EACH_ENTRY(mnt, mntList, struct Mount, mountList) {
+        if (mnt->vnodeDev == dev) {
+            return mnt;
+        }
+    }
+    return NULL;
+}
+
+static void DirPreClose(struct fs_dirent_s *dirp)
+{
+    struct Vnode *node = NULL;
+    if (dirp == NULL || dirp->fd_root == NULL) {
+        return;
+    }
+
+    node = dirp->fd_root;
+    if (node->vop && node->vop->Closedir) {
+        node->vop->Closedir(node, dirp);
+    }
+}
+
+static void FilePreClose(struct file *filep, const struct file_operations_vfs *ops)
+{
+    if (filep->f_oflags & O_DIRECTORY) {
+        DirPreClose(filep->f_dir);
+        return;
+    }
+
+    if (ops && ops->close) {
+        ops->close(filep);
+    }
+}
+
+static void FileDisableAndClean(struct Mount *mnt)
+{
+    struct filelist *flist = &tg_filelist;
+    struct file *filep = NULL;
+    const struct file_operations_vfs *originOps;
+
+    for (int i = 3; i < CONFIG_NFILE_DESCRIPTORS; i++) {
+        if (!get_bit(i)) {
+            continue;
+        }
+        filep = &flist->fl_files[i];
+        if (filep == NULL || filep->f_vnode == NULL) {
+            continue;
+        }
+        if (filep->f_vnode->originMount != mnt) {
+            continue;
+        }
+        originOps = filep->ops;
+        filep->ops = &g_errorFileOps;
+        FilePreClose(filep, originOps);
+    }
+}
+
+static void VnodeTryFree(struct Vnode *vnode)
+{
+    if (vnode->useCount == 0) {
+        VnodeFree(vnode);
+        return;
+    }
+
+    VnodePathCacheFree(vnode);
+    LOS_ListDelete(&(vnode->hashEntry));
+    LOS_ListDelete(&vnode->actFreeEntry);
+
+    if (vnode->vop->Reclaim) {
+        vnode->vop->Reclaim(vnode);
+    }
+    vnode->vop = &g_errorVnodeOps;
+    vnode->fop = &g_errorFileOps;
+}
+
+static void VnodeTryFreeAll(struct Mount *mount)
+{
+    struct Vnode *vnode = NULL;
+    struct Vnode *nextVnode = NULL;
+
+    LOS_DL_LIST_FOR_EACH_ENTRY_SAFE(vnode, nextVnode, GetVnodeActiveList(), struct Vnode, actFreeEntry) {
+        if ((vnode->originMount != mount) || (vnode->flag & VNODE_FLAG_MOUNT_NEW)) {
+            continue;
+        }
+        VnodeTryFree(vnode);
+    }
+}
+
+int ForceUmountDev(struct Vnode *dev)
+{
+    int ret;
+    struct Vnode *origin;
+    struct filelist *flist = &tg_filelist;
+    if (dev == NULL) {
+        return -EINVAL;
+    }
+
+    (void)sem_wait(&flist->fl_sem);
+    VnodeHold();
+
+    struct Mount *mnt = GetDevMountPoint(dev);
+    if (mnt == NULL) {
+        VnodeDrop();
+        (void)sem_post(&flist->fl_sem);
+        return -ENXIO;
+    }
+    origin = mnt->vnodeBeCovered;
+
+    FileDisableAndClean(mnt);
+    VnodeTryFreeAll(mnt);
+    ret = mnt->ops->Unmount(mnt, &dev);
+    if (ret != OK) {
+        PRINT_ERR("unmount in fs failed, ret = %d, errno = %d\n", ret, errno);
+    }
+
+    LOS_ListDelete(&mnt->mountList);
+    free(mnt);
+    origin->newMount = NULL;
+    origin->flag &= ~(VNODE_FLAG_MOUNT_ORIGIN);
+
+    VnodeDrop();
+    (void)sem_post(&flist->fl_sem);
+
+    return OK;
+}