[07a3253d] | 1 | /* |
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| 2 | * unmount() - Unmount a File System |
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| 3 | * |
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| 4 | * This routine is not defined in the POSIX 1003.1b standard but |
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| 5 | * in some form is supported on most UNIX and POSIX systems. This |
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| 6 | * routine is necessary to mount instantiations of a file system |
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| 7 | * into the file system name space. |
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| 8 | * |
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[08311cc3] | 9 | * COPYRIGHT (c) 1989-1999. |
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[07a3253d] | 10 | * On-Line Applications Research Corporation (OAR). |
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| 11 | * |
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| 12 | * The license and distribution terms for this file may be |
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| 13 | * found in the file LICENSE in this distribution or at |
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| 14 | * http://www.OARcorp.com/rtems/license.html. |
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| 15 | * |
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| 16 | * $Id$ |
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| 17 | */ |
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| 18 | |
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| 19 | #include <sys/types.h> |
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| 20 | #include <sys/stat.h> |
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| 21 | #include <chain.h> |
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| 22 | #include <fcntl.h> |
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| 23 | #include <unistd.h> |
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| 24 | #include <errno.h> |
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| 25 | #include <stdlib.h> |
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| 26 | #include <string.h> |
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| 27 | #include <assert.h> |
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| 28 | |
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[3ba74c73] | 29 | #include <rtems/libio_.h> |
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[07a3253d] | 30 | |
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| 31 | /* |
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| 32 | * Data structures and routines private to mount/unmount pair. |
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| 33 | */ |
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| 34 | |
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| 35 | extern Chain_Control rtems_filesystem_mount_table_control; |
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| 36 | extern rtems_filesystem_location_info_t rtems_filesystem_current; |
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| 37 | |
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| 38 | int search_mt_for_mount_point( |
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| 39 | rtems_filesystem_location_info_t *location_of_mount_point |
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| 40 | ); |
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| 41 | |
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| 42 | |
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| 43 | int file_systems_below_this_mountpoint( |
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[4b0d1ab] | 44 | const char *path, |
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[07a3253d] | 45 | rtems_filesystem_location_info_t *temp_loc, |
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| 46 | rtems_filesystem_mount_table_entry_t *temp_mt_entry |
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| 47 | ); |
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| 48 | |
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| 49 | /* |
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| 50 | * unmount |
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| 51 | * |
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| 52 | * This routine will attempt to unmount the file system that has been |
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[4b0d1ab] | 53 | * is mounted a path. If the operation is successful, 0 will |
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[07a3253d] | 54 | * be returned to the calling routine. Otherwise, 1 will be returned. |
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| 55 | */ |
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| 56 | |
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| 57 | int unmount( |
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[4b0d1ab] | 58 | const char *path |
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[07a3253d] | 59 | ) |
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| 60 | { |
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| 61 | int status; |
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[4b0d1ab] | 62 | rtems_filesystem_location_info_t fs_root_loc; |
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[07a3253d] | 63 | rtems_filesystem_mount_table_entry_t temp_mt_entry; |
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| 64 | |
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| 65 | /* |
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[4b0d1ab] | 66 | * Are there any file systems below the path specified |
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[07a3253d] | 67 | */ |
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| 68 | |
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| 69 | status = file_systems_below_this_mountpoint( |
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[4b0d1ab] | 70 | path, |
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| 71 | &fs_root_loc, |
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[07a3253d] | 72 | &temp_mt_entry |
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| 73 | ); |
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| 74 | |
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| 75 | if ( status != 0 ) |
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| 76 | return -1; |
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| 77 | |
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| 78 | /* |
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| 79 | * Is the current node reference pointing to a node in the file system |
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| 80 | * we are attempting to unmount ? |
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| 81 | */ |
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| 82 | |
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[4b0d1ab] | 83 | if ( rtems_filesystem_current.mt_entry == fs_root_loc.mt_entry ) { |
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| 84 | rtems_filesystem_freenode( &fs_root_loc ); |
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[07a3253d] | 85 | set_errno_and_return_minus_one( EBUSY ); |
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[d71fcab] | 86 | } |
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[07a3253d] | 87 | |
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| 88 | /* |
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| 89 | * Run the file descriptor table to determine if there are any file |
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| 90 | * descriptors that are currently active and reference nodes in the |
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| 91 | * file system that we are trying to unmount |
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| 92 | */ |
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| 93 | |
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[4b0d1ab] | 94 | if ( rtems_libio_is_open_files_in_fs( fs_root_loc.mt_entry ) == 1 ) { |
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| 95 | rtems_filesystem_freenode( &fs_root_loc ); |
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[07a3253d] | 96 | set_errno_and_return_minus_one( EBUSY ); |
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[d71fcab] | 97 | } |
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[07a3253d] | 98 | |
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| 99 | /* |
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[4b0d1ab] | 100 | * Allow the file system being unmounted on to do its cleanup. |
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[07a3253d] | 101 | */ |
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| 102 | |
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[4b0d1ab] | 103 | if ((temp_mt_entry.mt_point_node.ops->unmount_h )( fs_root_loc.mt_entry ) != 0 ) { |
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| 104 | rtems_filesystem_freenode( &fs_root_loc ); |
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[d71fcab] | 105 | return -1; |
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| 106 | } |
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[07a3253d] | 107 | |
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| 108 | /* |
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| 109 | * Run the unmount function for the subordinate file system. |
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| 110 | */ |
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| 111 | |
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[4b0d1ab] | 112 | if ((temp_mt_entry.mt_fs_root.ops->fsunmount_me_h )( fs_root_loc.mt_entry ) != 0){ |
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| 113 | rtems_filesystem_freenode( &fs_root_loc ); |
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[dd0f326] | 114 | return -1; |
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[d71fcab] | 115 | } |
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[07a3253d] | 116 | |
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| 117 | /* |
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| 118 | * Extract the mount table entry from the chain |
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| 119 | */ |
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| 120 | |
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[4b0d1ab] | 121 | Chain_Extract( ( Chain_Node * ) fs_root_loc.mt_entry ); |
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[07a3253d] | 122 | |
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| 123 | /* |
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| 124 | * Free the memory associated with the extracted mount table entry. |
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| 125 | */ |
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| 126 | |
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[4b0d1ab] | 127 | rtems_filesystem_freenode( &fs_root_loc.mt_entry->mt_point_node ); |
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| 128 | free( fs_root_loc.mt_entry ); |
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| 129 | rtems_filesystem_freenode( &fs_root_loc ); |
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[07a3253d] | 130 | |
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[df49c60] | 131 | return 0; |
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[07a3253d] | 132 | } |
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| 133 | |
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| 134 | |
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| 135 | /* |
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| 136 | * file_systems_below_this_mountpoint |
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| 137 | * |
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| 138 | * This routine will run through the entries that currently exist in the |
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| 139 | * mount table chain. For each entry in the mount table chain it will |
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| 140 | * compare the mount tables mt_fs_root to the new_fs_root_node. If any of the |
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| 141 | * mount table file system root nodes matches the new file system root node |
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| 142 | * this indicates that we are trying to mount a file system that has already |
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| 143 | * been mounted. This is not a permitted operation. temp_loc is set to |
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| 144 | * the root node of the file system being unmounted. |
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| 145 | */ |
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| 146 | |
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| 147 | int file_systems_below_this_mountpoint( |
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[4b0d1ab] | 148 | const char *path, |
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| 149 | rtems_filesystem_location_info_t *fs_root_loc, |
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| 150 | rtems_filesystem_mount_table_entry_t *fs_to_unmount |
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[07a3253d] | 151 | ) |
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| 152 | { |
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| 153 | Chain_Node *the_node; |
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| 154 | rtems_filesystem_mount_table_entry_t *the_mount_entry; |
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| 155 | |
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| 156 | /* |
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[4b0d1ab] | 157 | * Is the path even a valid node name in the existing tree? |
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[07a3253d] | 158 | */ |
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| 159 | |
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[4b0d1ab] | 160 | if ( rtems_filesystem_evaluate_path( path, 0x0, fs_root_loc, TRUE ) ) |
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[07a3253d] | 161 | return -1; |
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| 162 | |
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| 163 | /* |
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[4b0d1ab] | 164 | * Verify this is the root node for the file system to be unmounted. |
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[07a3253d] | 165 | */ |
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| 166 | |
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[4b0d1ab] | 167 | *fs_to_unmount = *fs_root_loc->mt_entry; |
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| 168 | if ( fs_to_unmount->mt_fs_root.node_access != fs_root_loc->node_access ) |
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| 169 | set_errno_and_return_minus_one( EACCES ); |
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[07a3253d] | 170 | |
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[4b0d1ab] | 171 | /* |
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| 172 | * Search the mount table for any mount entries referencing this |
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| 173 | * mount entry. |
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| 174 | */ |
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[07a3253d] | 175 | |
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| 176 | for ( the_node = rtems_filesystem_mount_table_control.first; |
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| 177 | !Chain_Is_tail( &rtems_filesystem_mount_table_control, the_node ); |
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| 178 | the_node = the_node->next ) { |
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[4b0d1ab] | 179 | the_mount_entry = ( rtems_filesystem_mount_table_entry_t * )the_node; |
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| 180 | if (the_mount_entry->mt_point_node.mt_entry == fs_root_loc->mt_entry ) { |
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[07a3253d] | 181 | set_errno_and_return_minus_one( EBUSY ); |
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| 182 | } |
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| 183 | } |
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| 184 | |
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| 185 | return 0; |
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| 186 | } |
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