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2001-10-25 Jennifer Averett <jennifer@OARcorp.com>

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* libc/unmount.c: Primarily restructuring and clean up to address
	procedures which did not do what their name implied.  Also addressed
	problem situation where unmount fails and the filesystem was
	inconsistent.  The mounted filesystem could have been left hanging.
This commit is contained in:
Joel Sherrill
2001-10-25 17:41:07 +00:00
parent 1af7963479
commit 9c30d6a9a6
4 changed files with 421 additions and 330 deletions
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248
c/src/exec/libcsupport/src/unmount.c
View File

@@ -42,96 +42,11 @@ int search_mt_for_mount_point(
rtems_filesystem_location_info_t *location_of_mount_point
);
int file_systems_below_this_mountpoint(
const char *path,
rtems_filesystem_location_info_t *temp_loc,
rtems_filesystem_mount_table_entry_t *temp_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
)
{
int status;
rtems_filesystem_location_info_t fs_root_loc;
rtems_filesystem_mount_table_entry_t temp_mt_entry;
/*
* Are there any file systems below the path specified
*/
status = file_systems_below_this_mountpoint(
path,
&fs_root_loc,
&temp_mt_entry
);
if ( status != 0 )
return -1;
/*
* Is the current node reference pointing to a node in the file system
* we are attempting to unmount ?
*/
if ( rtems_filesystem_current.mt_entry == fs_root_loc.mt_entry ) {
rtems_filesystem_freenode( &fs_root_loc );
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( fs_root_loc.mt_entry ) == 1 ) {
rtems_filesystem_freenode( &fs_root_loc );
set_errno_and_return_minus_one( EBUSY );
}
/*
* Allow the file system being unmounted on to do its cleanup.
*/
if ((temp_mt_entry.mt_point_node.ops->unmount_h )( fs_root_loc.mt_entry ) != 0 ) {
rtems_filesystem_freenode( &fs_root_loc );
return -1;
}
/*
* Run the unmount function for the subordinate file system.
*/
if ((temp_mt_entry.mt_fs_root.ops->fsunmount_me_h )( fs_root_loc.mt_entry ) != 0){
rtems_filesystem_freenode( &fs_root_loc );
return -1;
}
/*
* Extract the mount table entry from the chain
*/
Chain_Extract( ( Chain_Node * ) fs_root_loc.mt_entry );
/*
* Free the memory associated with the extracted mount table entry.
*/
rtems_filesystem_freenode( &fs_root_loc.mt_entry->mt_point_node );
free( fs_root_loc.mt_entry );
rtems_filesystem_freenode( &fs_root_loc );
return 0;
rtems_boolean rtems_filesystem_nodes_equal(
const rtems_filesystem_location_info_t *loc1,
const rtems_filesystem_location_info_t *loc2
){
return ( loc1->node_access == loc2->node_access );
}
@@ -147,7 +62,7 @@ int unmount(
* the root node of the file system being unmounted.
*/
int file_systems_below_this_mountpoint(
rtems_boolean file_systems_below_this_mountpoint(
const char *path,
rtems_filesystem_location_info_t *fs_root_loc,
rtems_filesystem_mount_table_entry_t *fs_to_unmount
@@ -156,23 +71,6 @@ int file_systems_below_this_mountpoint(
Chain_Node *the_node;
rtems_filesystem_mount_table_entry_t *the_mount_entry;
/*
* Is the path even a valid node name in the existing tree?
*/
if ( rtems_filesystem_evaluate_path( path, 0x0, fs_root_loc, TRUE ) )
return -1;
/*
* Verify this is the root node for the file system to be unmounted.
*/
*fs_to_unmount = *fs_root_loc->mt_entry;
if ( fs_to_unmount->mt_fs_root.node_access != fs_root_loc->node_access ){
rtems_filesystem_freenode(fs_root_loc);
set_errno_and_return_minus_one( EACCES );
}
/*
* Search the mount table for any mount entries referencing this
* mount entry.
@@ -183,10 +81,140 @@ int file_systems_below_this_mountpoint(
the_node = the_node->next ) {
the_mount_entry = ( rtems_filesystem_mount_table_entry_t * )the_node;
if (the_mount_entry->mt_point_node.mt_entry == fs_root_loc->mt_entry ) {
rtems_filesystem_freenode(fs_root_loc);
set_errno_and_return_minus_one( EBUSY );
return TRUE;
}
}
return FALSE;
}
/*
* 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, 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 ( !rtems_filesystem_nodes_equal( fs_root_loc, &loc) ){
rtems_filesystem_freenode( &loc );
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 Unmount is supported by both filesystems.
*/
if ( !fs_mount_loc->ops->unmount_h )
set_errno_and_return_minus_one( ENOTSUP );
if ( !fs_root_loc->ops->fsunmount_me_h )
set_errno_and_return_minus_one( ENOTSUP );
/*
* 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 )
set_errno_and_return_minus_one( EBUSY );
/*
* Verify there are no file systems below the path specified
*/
if ( file_systems_below_this_mountpoint( path, fs_root_loc, mt_entry ) != 0 )
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 )
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
*/
Chain_Extract( ( Chain_Node * ) mt_entry );
/*
* 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;
}