/**************************************************************************** * fs/mount/fs_mount.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include "inode/inode.h" #include "driver/driver.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* Configuration ************************************************************/ /* In the canonical case, a file system is bound to a block driver. However, * some less typical cases a block driver is not required. Examples are * pseudo file systems (like BINFS or PROCFS) and MTD file systems (like * NXFFS). * * These file systems all require block drivers: */ #if defined(CONFIG_FS_FAT) || defined(CONFIG_FS_ROMFS) || \ defined(CONFIG_FS_SMARTFS) || defined(CONFIG_FS_LITTLEFS) # define BDFS_SUPPORT 1 #endif /* These file systems require MTD drivers */ #if (defined(CONFIG_FS_SPIFFS) || defined(CONFIG_FS_LITTLEFS)) && \ defined(CONFIG_MTD) # define MDFS_SUPPORT 1 #endif /* These file systems do not require block or MTD drivers */ #if defined(CONFIG_FS_NXFFS) || defined(CONFIG_FS_BINFS) || \ defined(CONFIG_FS_PROCFS) || defined(CONFIG_NFS) || \ defined(CONFIG_FS_TMPFS) || defined(CONFIG_FS_USERFS) || \ defined(CONFIG_FS_CROMFS) || defined(CONFIG_FS_UNIONFS) || \ defined(CONFIG_FS_HOSTFS) # define NODFS_SUPPORT #endif /**************************************************************************** * Private Types ****************************************************************************/ struct fsmap_t { FAR const char *fs_filesystemtype; FAR const struct mountpt_operations *fs_mops; }; /**************************************************************************** * Private Data ****************************************************************************/ #ifdef BDFS_SUPPORT /* File systems that require block drivers */ #ifdef CONFIG_FS_FAT extern const struct mountpt_operations fat_operations; #endif #ifdef CONFIG_FS_ROMFS extern const struct mountpt_operations romfs_operations; #endif #ifdef CONFIG_FS_SMARTFS extern const struct mountpt_operations smartfs_operations; #endif #ifdef CONFIG_FS_LITTLEFS extern const struct mountpt_operations littlefs_operations; #endif static const struct fsmap_t g_bdfsmap[] = { #ifdef CONFIG_FS_FAT { "vfat", &fat_operations }, #endif #ifdef CONFIG_FS_ROMFS { "romfs", &romfs_operations }, #endif #ifdef CONFIG_FS_SMARTFS { "smartfs", &smartfs_operations }, #endif #ifdef CONFIG_FS_LITTLEFS { "littlefs", &littlefs_operations }, #endif { NULL, NULL }, }; #endif /* BDFS_SUPPORT */ #ifdef MDFS_SUPPORT /* File systems that require MTD drivers */ #ifdef CONFIG_FS_ROMFS extern const struct mountpt_operations romfs_operations; #endif #ifdef CONFIG_FS_SPIFFS extern const struct mountpt_operations spiffs_operations; #endif #ifdef CONFIG_FS_LITTLEFS extern const struct mountpt_operations littlefs_operations; #endif static const struct fsmap_t g_mdfsmap[] = { #ifdef CONFIG_FS_ROMFS { "romfs", &romfs_operations }, #endif #ifdef CONFIG_FS_SPIFFS { "spiffs", &spiffs_operations }, #endif #ifdef CONFIG_FS_LITTLEFS { "littlefs", &littlefs_operations }, #endif { NULL, NULL }, }; #endif /* MDFS_SUPPORT */ #ifdef NODFS_SUPPORT /* File systems that require neither block nor MTD drivers */ #ifdef CONFIG_FS_NXFFS extern const struct mountpt_operations nxffs_operations; #endif #ifdef CONFIG_FS_TMPFS extern const struct mountpt_operations tmpfs_operations; #endif #ifdef CONFIG_NFS extern const struct mountpt_operations nfs_operations; #endif #ifdef CONFIG_FS_BINFS extern const struct mountpt_operations binfs_operations; #endif #ifdef CONFIG_FS_PROCFS extern const struct mountpt_operations procfs_operations; #endif #ifdef CONFIG_FS_USERFS extern const struct mountpt_operations userfs_operations; #endif #ifdef CONFIG_FS_HOSTFS extern const struct mountpt_operations hostfs_operations; #endif #ifdef CONFIG_FS_CROMFS extern const struct mountpt_operations cromfs_operations; #endif #ifdef CONFIG_FS_UNIONFS extern const struct mountpt_operations unionfs_operations; #endif static const struct fsmap_t g_nonbdfsmap[] = { #ifdef CONFIG_FS_NXFFS { "nxffs", &nxffs_operations }, #endif #ifdef CONFIG_FS_TMPFS { "tmpfs", &tmpfs_operations }, #endif #ifdef CONFIG_NFS { "nfs", &nfs_operations }, #endif #ifdef CONFIG_FS_BINFS { "binfs", &binfs_operations }, #endif #ifdef CONFIG_FS_PROCFS { "procfs", &procfs_operations }, #endif #ifdef CONFIG_FS_USERFS { "userfs", &userfs_operations }, #endif #ifdef CONFIG_FS_HOSTFS { "hostfs", &hostfs_operations }, #endif #ifdef CONFIG_FS_CROMFS { "cromfs", &cromfs_operations }, #endif #ifdef CONFIG_FS_UNIONFS { "unionfs", &unionfs_operations }, #endif { NULL, NULL }, }; #endif /* NODFS_SUPPORT */ /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: mount_findfs * * Description: * find the specified filesystem * ****************************************************************************/ #if defined(BDFS_SUPPORT) || defined(MDFS_SUPPORT) || defined(NODFS_SUPPORT) static FAR const struct mountpt_operations * mount_findfs(FAR const struct fsmap_t *fstab, FAR const char *filesystemtype) { FAR const struct fsmap_t *fsmap; for (fsmap = fstab; fsmap->fs_filesystemtype; fsmap++) { if (strcmp(filesystemtype, fsmap->fs_filesystemtype) == 0) { return fsmap->fs_mops; } } return NULL; } #endif /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: nx_mount * * Description: * nx_mount() is similar to the standard 'mount' interface except that is * not a cancellation point and it does not modify the errno variable. * * nx_mount() is an internal NuttX interface and should not be called from * applications. * * Returned Value: * Zero is returned on success; a negated value is returned on any failure. * ****************************************************************************/ int nx_mount(FAR const char *source, FAR const char *target, FAR const char *filesystemtype, unsigned long mountflags, FAR const void *data) { #if defined(BDFS_SUPPORT) || defined(MDFS_SUPPORT) || defined(NODFS_SUPPORT) #if defined(BDFS_SUPPORT) || defined(MDFS_SUPPORT) FAR struct inode *drvr_inode = NULL; #endif FAR struct inode *mountpt_inode; FAR const struct mountpt_operations *mops; #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS struct inode_search_s desc; #endif void *fshandle; int ret; /* Verify required pointer arguments */ DEBUGASSERT(target && filesystemtype); /* Find the specified filesystem. Try the block driver filesystems first */ #ifdef BDFS_SUPPORT if (source != NULL && find_blockdriver(source, mountflags, &drvr_inode) >= 0) { /* Find the block based file system */ mops = mount_findfs(g_bdfsmap, filesystemtype); if (mops == NULL) { ferr("ERROR: Failed to find block based file system %s\n", filesystemtype); ret = -ENODEV; goto errout_with_inode; } } else #endif /* BDFS_SUPPORT */ #ifdef MDFS_SUPPORT if (source != NULL && (ret = find_mtddriver(source, &drvr_inode)) >= 0) { /* Find the MTD based file system */ mops = mount_findfs(g_mdfsmap, filesystemtype); if (mops == NULL) { ferr("ERROR: Failed to find MTD based file system %s\n", filesystemtype); ret = -ENODEV; goto errout_with_inode; } } else #endif /* MDFS_SUPPORT */ #ifdef NODFS_SUPPORT if ((mops = mount_findfs(g_nonbdfsmap, filesystemtype)) != NULL) { } else #endif /* NODFS_SUPPORT */ { ferr("ERROR: Failed to find block driver %s\n", source); ret = -ENOTBLK; goto errout; } ret = inode_semtake(); if (ret < 0) { goto errout_with_inode; } #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS /* Check if the inode already exists */ SETUP_SEARCH(&desc, target, false); ret = inode_find(&desc); if (ret >= 0) { /* Successfully found. The reference count on the inode has been * incremented. */ mountpt_inode = desc.node; DEBUGASSERT(mountpt_inode != NULL); /* But is it a directory node (i.e., not a driver or other special * node)? */ if (INODE_IS_SPECIAL(mountpt_inode)) { ferr("ERROR: target %s exists and is a special node\n", target); ret = -ENOTDIR; inode_release(mountpt_inode); goto errout_with_semaphore; } } else #endif /* Insert a dummy node -- we need to hold the inode semaphore * to do this because we will have a momentarily bad structure. * NOTE that the new inode will be created with an initial reference * count of zero. */ { ret = inode_reserve(target, &mountpt_inode); if (ret < 0) { /* inode_reserve can fail for a couple of reasons, but the most * likely one is that the inode already exists. inode_reserve may * return: * * -EINVAL - 'path' is invalid for this operation * -EEXIST - An inode already exists at 'path' * -ENOMEM - Failed to allocate in-memory resources for the * operation */ ferr("ERROR: Failed to reserve inode for target %s\n", target); goto errout_with_semaphore; } } /* Bind the block driver to an instance of the file system. The file * system returns a reference to some opaque, fs-dependent structure * that encapsulates this binding. */ if (mops->bind == NULL) { /* The filesystem does not support the bind operation ??? */ ferr("ERROR: Filesystem does not support bind\n"); ret = -EINVAL; goto errout_with_mountpt; } /* Increment reference count for the reference we pass to the file system */ #if defined(BDFS_SUPPORT) || defined(MDFS_SUPPORT) #ifdef NODFS_SUPPORT if (drvr_inode != NULL) #endif { drvr_inode->i_crefs++; } #endif /* On failure, the bind method returns -errorcode */ #if defined(BDFS_SUPPORT) || defined(MDFS_SUPPORT) ret = mops->bind(drvr_inode, data, &fshandle); #else ret = mops->bind(NULL, data, &fshandle); #endif if (ret < 0) { /* The inode is unhappy with the driver for some reason. Back out * the count for the reference we failed to pass and exit with an * error. */ ferr("ERROR: Bind method failed: %d\n", ret); #if defined(BDFS_SUPPORT) || defined(MDFS_SUPPORT) #ifdef NODFS_SUPPORT if (drvr_inode != NULL) #endif { drvr_inode->i_crefs--; } #endif goto errout_with_mountpt; } /* We have it, now populate it with driver specific information. */ INODE_SET_MOUNTPT(mountpt_inode); mountpt_inode->u.i_mops = mops; #ifdef CONFIG_FILE_MODE mountpt_inode->i_mode = mode; #endif mountpt_inode->i_private = fshandle; inode_semgive(); /* We can release our reference to the blkdrver_inode, if the filesystem * wants to retain the blockdriver inode (which it should), then it must * have called inode_addref(). There is one reference on mountpt_inode * that will persist until umount2() is called. */ #if defined(BDFS_SUPPORT) || defined(MDFS_SUPPORT) #ifdef NODFS_SUPPORT if (drvr_inode != NULL) #endif { inode_release(drvr_inode); } #endif #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS RELEASE_SEARCH(&desc); #endif return OK; /* A lot of goto's! But they make the error handling much simpler */ errout_with_mountpt: inode_remove(target); inode_release(mountpt_inode); errout_with_semaphore: inode_semgive(); #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS RELEASE_SEARCH(&desc); #endif errout_with_inode: #if defined(BDFS_SUPPORT) || defined(MDFS_SUPPORT) if (drvr_inode != NULL) { inode_release(drvr_inode); } #endif errout: return ret; #else ferr("ERROR: No filesystems enabled\n"); return -ENOSYS; #endif /* BDFS_SUPPORT || MDFS_SUPPORT || NODFS_SUPPORT */ } /**************************************************************************** * Name: mount * * Description: * mount() attaches the filesystem specified by the 'source' block device * name into the root file system at the path specified by 'target.' * * Returned Value: * Zero is returned on success; -1 is returned on an error and errno is * set appropriately: * * EACCES A component of a path was not searchable or mounting a read-only * filesystem was attempted without giving the MS_RDONLY flag. * EBUSY 'source' is already mounted. * EFAULT One of the pointer arguments points outside the user address * space. * EINVAL 'source' had an invalid superblock. * ENODEV 'filesystemtype' not configured * ENOENT A pathname was empty or had a nonexistent component. * ENOMEM Could not allocate a memory to copy filenames or data into. * ENOTBLK 'source' is not a block device * ****************************************************************************/ int mount(FAR const char *source, FAR const char *target, FAR const char *filesystemtype, unsigned long mountflags, FAR const void *data) { int ret; ret = nx_mount(source, target, filesystemtype, mountflags, data); if (ret < 0) { set_errno(-ret); ret = ERROR; } return ret; }