diff options
Diffstat (limited to 'cpukit/libcsupport/src/unmount.c')
| -rw-r--r-- | cpukit/libcsupport/src/unmount.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/cpukit/libcsupport/src/unmount.c b/cpukit/libcsupport/src/unmount.c new file mode 100644 index 0000000000..a2c67f7098 --- /dev/null +++ b/cpukit/libcsupport/src/unmount.c @@ -0,0 +1,162 @@ +/* + * unmount() - Unmount a File System + * + * This routine is not defined in the POSIX 1003.1b standard but + * in some form is supported on most UNIX and POSIX systems. This + * routine is necessary to mount instantiations of a file system + * into the file system name space. + * + * COPYRIGHT (c) 1989-2010. + * 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 <fcntl.h> +#include <unistd.h> +#include <errno.h> +#include <stdlib.h> +#include <string.h> + +#include <rtems/libio_.h> +#include <rtems/seterr.h> +#include <rtems/chain.h> + +static bool is_fs_below_mount_point( + const rtems_filesystem_mount_table_entry_t *mt_entry, + void *arg +) +{ + return arg == mt_entry->mt_point_node.mt_entry; +} + +/* + * unmount + * + * This routine will attempt to unmount the file system that has been + * is mounted a path. If the operation is successful, 0 will + * be returned to the calling routine. Otherwise, 1 will be returned. + */ + +int unmount( + const char *path +) +{ + rtems_filesystem_location_info_t loc; + rtems_filesystem_location_info_t *fs_root_loc; + rtems_filesystem_location_info_t *fs_mount_loc; + rtems_filesystem_mount_table_entry_t *mt_entry; + + /* + * Get + * The root node of the mounted filesytem. + * The node for the directory that the fileystem is mounted on. + * The mount entry that is being refered to. + */ + + if ( rtems_filesystem_evaluate_path( path, strlen( path ), 0x0, &loc, true ) ) + return -1; + + mt_entry = loc.mt_entry; + fs_mount_loc = &mt_entry->mt_point_node; + fs_root_loc = &mt_entry->mt_fs_root; + + /* + * Verify this is the root node for the file system to be unmounted. + */ + + if ( fs_root_loc->node_access != loc.node_access ){ + rtems_filesystem_freenode( &loc ); + rtems_set_errno_and_return_minus_one( EACCES ); + } + + /* + * Free the loc node and just use the nodes from the mt_entry . + */ + + rtems_filesystem_freenode( &loc ); + + /* + * Verify the current node is not in this filesystem. + * XXX - Joel I have a question here wasn't code added + * that made the current node thread based instead + * of system based? I thought it was but it doesn't + * look like it in this version. + */ + + if ( rtems_filesystem_current.mt_entry == mt_entry ) + rtems_set_errno_and_return_minus_one( EBUSY ); + + /* + * Verify there are no file systems below the path specified + */ + + if ( rtems_filesystem_mount_iterate( is_fs_below_mount_point, + fs_root_loc->mt_entry ) ) + rtems_set_errno_and_return_minus_one( EBUSY ); + + /* + * Run the file descriptor table to determine if there are any file + * descriptors that are currently active and reference nodes in the + * file system that we are trying to unmount + */ + + if ( rtems_libio_is_open_files_in_fs( mt_entry ) == 1 ) + rtems_set_errno_and_return_minus_one( EBUSY ); + + /* + * Allow the file system being unmounted on to do its cleanup. + * If it fails it will set the errno to the approprate value + * and the fileystem will not be modified. + */ + + if (( fs_mount_loc->ops->unmount_h )( mt_entry ) != 0 ) + return -1; + + /* + * Allow the mounted filesystem to unmark the use of the root node. + * + * Run the unmount function for the subordinate file system. + * + * If we fail to unmount the filesystem remount it on the base filesystems + * directory node. + * + * NOTE: Fatal error is called in a case which should never happen + * This was response was questionable but the best we could + * come up with. + */ + + if ((fs_root_loc->ops->fsunmount_me_h )( mt_entry ) != 0){ + if (( fs_mount_loc->ops->mount_h )( mt_entry ) != 0 ) + rtems_fatal_error_occurred( 0 ); + return -1; + } + + /* + * Extract the mount table entry from the chain + */ + + rtems_libio_lock(); + rtems_chain_extract( &mt_entry->Node ); + rtems_libio_unlock(); + + /* + * Free the memory node that was allocated in mount + * Free the memory associated with the extracted mount table entry. + */ + + rtems_filesystem_freenode( fs_mount_loc ); + free( mt_entry ); + + return 0; +} |