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[/] [openrisc/] [trunk/] [rtos/] [rtems/] [c/] [src/] [lib/] [libc/] [mount.c] - Rev 751
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/* * mount() * * XXX * * XXX make sure no required ops are NULL * XXX make sure no optional ops you are using are NULL * XXX unmount should be required. * * COPYRIGHT (c) 1989-1999. * On-Line Applications Research Corporation (OAR). * * The license and distribution terms for this file may be * found in the file LICENSE in this distribution or at * http://www.OARcorp.com/rtems/license.html. * * $Id: mount.c,v 1.2 2001-09-27 12:01:15 chris Exp $ */ #include <sys/types.h> #include <sys/stat.h> #include <chain.h> #include <fcntl.h> #include <unistd.h> #include <errno.h> #include <stdlib.h> #include <string.h> #include <assert.h> #include "libio_.h" Chain_Control rtems_filesystem_mount_table_control; #include "imfs.h" /* XXX this structure should be in an IMFS specific file */ /* XXX this structure should use real constants */ rtems_filesystem_limits_and_options_t IMFS_LIMITS_AND_OPTIONS = { 5, /* link_max */ 6, /* max_canon */ 7, /* max_input */ IMFS_NAME_MAX, /* name_max */ 255, /* path_max */ 2, /* pipe_buf */ 1, /* posix_async_io */ 2, /* posix_chown_restrictions */ 3, /* posix_no_trunc */ 4, /* posix_prio_io */ 5, /* posix_sync_io */ 6 /* posix_vdisable */ }; /* * XXX */ int search_mt_for_mount_point( rtems_filesystem_location_info_t *location_of_mount_point ); int init_fs_mount_table( void ); /* * XXX */ #define FOUND 0 #define NOT_FOUND -1 /* * mount * * This routine will attempt to mount a new file system at the specified * mount point. A series of tests will be run to determine if any of the * following reasons exist to prevent the mount operation: * * 1) The file system type or options are not valid * 2) No new file system root node is specified * 3) The selected file system has already been mounted * 4) The mount point exists with the proper permissions to allow mounting * 5) The selected mount point already has a file system mounted to it * */ int mount( rtems_filesystem_mount_table_entry_t **mt_entry, rtems_filesystem_operations_table *fs_ops, rtems_filesystem_options_t options, char *device, char *mount_point ) { rtems_filesystem_location_info_t loc; rtems_filesystem_mount_table_entry_t *temp_mt_entry; rtems_filesystem_location_info_t *loc_to_free = NULL; /* XXX add code to check for required operations */ /* * Is there a file system operations table? */ if ( fs_ops == NULL ) { errno = EINVAL; return -1; } /* * Are the file system options valid? */ if ( options != RTEMS_FILESYSTEM_READ_ONLY && options != RTEMS_FILESYSTEM_READ_WRITE ) { errno = EINVAL; return -1; } /* * Allocate a mount table entry */ temp_mt_entry = malloc( sizeof(rtems_filesystem_mount_table_entry_t) ); if ( !temp_mt_entry ) { errno = ENOMEM; return -1; } temp_mt_entry->mt_fs_root.mt_entry = temp_mt_entry; temp_mt_entry->options = options; if ( device ) strcpy( temp_mt_entry->dev, device ); else temp_mt_entry->dev = 0; /* * The mount_point should be a directory with read/write/execute * permissions in the existing tree. */ if ( mount_point ) { if ( rtems_filesystem_evaluate_path( mount_point, RTEMS_LIBIO_PERMS_RWX, &loc, TRUE ) == -1 ) goto cleanup_and_bail; /* * Test to see if it is a directory */ loc_to_free = &loc; if ( loc.ops->node_type( &loc ) != RTEMS_FILESYSTEM_DIRECTORY ) { errno = ENOTDIR; goto cleanup_and_bail; } /* * You can only mount one file system onto a single mount point. */ if ( search_mt_for_mount_point( &loc ) == FOUND ) { errno = EBUSY; goto cleanup_and_bail; } /* * This must be a good mount point, so move the location information * into the allocated mount entry. Note: the information that * may have been allocated in loc should not be sent to freenode * until the system is unmounted. It may be needed to correctly * traverse the tree. */ temp_mt_entry->mt_point_node.node_access = loc.node_access; temp_mt_entry->mt_point_node.handlers = loc.handlers; temp_mt_entry->mt_point_node.ops = loc.ops; temp_mt_entry->mt_point_node.mt_entry = loc.mt_entry; /* * This link to the parent is only done when we are dealing with system * below the base file system */ if ( !loc.ops->mount ){ errno = ENOTSUP; goto cleanup_and_bail; } if ( loc.ops->mount( temp_mt_entry ) ) { goto cleanup_and_bail; } } else { /* * This is a mount of the base file system --> The * mt_point_node.node_access will be set to null to indicate that this * is the root of the entire file system. */ temp_mt_entry->mt_fs_root.node_access = NULL; temp_mt_entry->mt_fs_root.handlers = NULL; temp_mt_entry->mt_fs_root.ops = NULL; temp_mt_entry->mt_point_node.node_access = NULL; temp_mt_entry->mt_point_node.handlers = NULL; temp_mt_entry->mt_point_node.ops = NULL; temp_mt_entry->mt_point_node.mt_entry = NULL; } if ( !fs_ops->fsmount_me ) { errno = ENOTSUP; goto cleanup_and_bail; } if ( fs_ops->fsmount_me( temp_mt_entry ) ) goto cleanup_and_bail; /* * Add the mount table entry to the mount table chain */ Chain_Append( &rtems_filesystem_mount_table_control, &temp_mt_entry->Node ); *mt_entry = temp_mt_entry; return 0; cleanup_and_bail: free( temp_mt_entry ); if ( loc_to_free ) rtems_filesystem_freenode( loc_to_free ); return -1; } /* * init_fs_mount_table * * This routine will initialize the chain control element that manages the * mount table chain. */ int init_fs_mount_table() { Chain_Initialize_empty ( &rtems_filesystem_mount_table_control ); return 0; } /* * search_mt_for_mount_point * * This routine will run through the entries that currently exist in the * mount table chain. For each entry in the mount table chain it will * compare the mount tables mt_point_node to the node describing the selected * mount point.. If any of the mount table file system mount point nodes * match the new file system selected mount point node, we are attempting * to mount the new file system onto a node that already has a file system * mounted to it. This is not a permitted operation. */ int search_mt_for_mount_point( rtems_filesystem_location_info_t *location_of_mount_point ) { Chain_Node *the_node; rtems_filesystem_mount_table_entry_t *the_mount_entry; for ( the_node = rtems_filesystem_mount_table_control.first; !Chain_Is_tail( &rtems_filesystem_mount_table_control, the_node ); the_node = the_node->next ) { the_mount_entry = (rtems_filesystem_mount_table_entry_t *) the_node; if ( the_mount_entry->mt_point_node.node_access == location_of_mount_point->node_access ) return FOUND; } return NOT_FOUND; }
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