diff options
Diffstat (limited to 'cpukit/libcsupport/src/mount.c')
| -rw-r--r-- | cpukit/libcsupport/src/mount.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/cpukit/libcsupport/src/mount.c b/cpukit/libcsupport/src/mount.c new file mode 100644 index 0000000000..bec64eb701 --- /dev/null +++ b/cpukit/libcsupport/src/mount.c @@ -0,0 +1,291 @@ +/* + * 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.rtems.com/license/LICENSE. + * + * $Id$ + */ + +#if HAVE_CONFIG_H +#include "config.h" +#endif + +#include <sys/types.h> +#include <sys/stat.h> +#include <rtems/chain.h> +#include <fcntl.h> +#include <unistd.h> +#include <errno.h> +#include <stdlib.h> +#include <string.h> +#include <assert.h> + +#include <rtems/libio_.h> + +Chain_Control rtems_filesystem_mount_table_control; + +/* + * Prototypes that probably should be somewhere else. + */ + +int init_fs_mount_table( void ); +static int Is_node_fs_root( + rtems_filesystem_location_info_t *loc +); + + +/* + * 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 = NULL; + rtems_filesystem_location_info_t *loc_to_free = NULL; + size_t size; + +/* 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; + } + + /* Do they support being mounted at all ? */ + if ( !fs_ops->fsmount_me_h ) { + errno = ENOTSUP; + goto cleanup_and_bail; + } + + + /* + * Allocate a mount table entry + */ + + size = sizeof(rtems_filesystem_mount_table_entry_t); + if ( device ) + size += strlen( device ) + 1; + temp_mt_entry = malloc( size ); + + 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 ) { + temp_mt_entry->dev = + (char *)temp_mt_entry + sizeof( rtems_filesystem_mount_table_entry_t ); + 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; + + loc_to_free = &loc; + + /* + * Test for node_type_h + */ + + if (!loc.ops->node_type_h) { + errno = ENOTSUP; + goto cleanup_and_bail; + } + + /* + * Test to see if it is a directory + */ + + if ( loc.ops->node_type_h( &loc ) != RTEMS_FILESYSTEM_DIRECTORY ) { + errno = ENOTDIR; + goto cleanup_and_bail; + } + + /* + * You can only mount one file system onto a single mount point. + */ + + if ( Is_node_fs_root( &loc ) ){ + 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_h ){ + errno = ENOTSUP; + goto cleanup_and_bail; + } + + if ( loc.ops->mount_h( 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_h( temp_mt_entry ) ) { + /* try to undo the mount operation */ + if ( loc.ops->unmount_h ) { + loc.ops->unmount_h( 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; +} + +/* + * Is_node_fs_root + * + * 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 root node to the node describing the selected + * mount point. If any match is found true is returned else false is + * returned. + * + */ + +static int Is_node_fs_root( + rtems_filesystem_location_info_t *loc +) +{ + Chain_Node *the_node; + rtems_filesystem_mount_table_entry_t *the_mount_entry; + + /* + * For each mount table 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_fs_root.node_access == loc->node_access ) + return TRUE; + } + return FALSE; +} |