diff options
Diffstat (limited to 'sys/ufs/ffs/softdep.h')
| -rw-r--r-- | sys/ufs/ffs/softdep.h | 32 |
1 files changed, 22 insertions, 10 deletions
diff --git a/sys/ufs/ffs/softdep.h b/sys/ufs/ffs/softdep.h index 3825bce4ce4e..16c8aea068ff 100644 --- a/sys/ufs/ffs/softdep.h +++ b/sys/ufs/ffs/softdep.h @@ -1,12 +1,14 @@ /* - * Copyright 1997 Marshall Kirk McKusick. All Rights Reserved. + * Copyright 1998 Marshall Kirk McKusick. All Rights Reserved. * - * The soft dependency code is derived from work done by Greg Ganger - * at the University of Michigan. + * The soft updates code is derived from the appendix of a University + * of Michigan technical report (Gregory R. Ganger and Yale N. Patt, + * "Soft Updates: A Solution to the Metadata Update Problem in File + * Systems", CSE-TR-254-95, August 1995). * * The following are the copyrights and redistribution conditions that - * apply to this copy of the soft dependency software. For a license - * to use, redistribute or sell the soft dependency software under + * apply to this copy of the soft update software. For a license + * to use, redistribute or sell the soft update software under * conditions other than those described here, please contact the * author at one of the following addresses: * @@ -24,12 +26,12 @@ * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. - * 3. None of the names of McKusick, Ganger, or the University of Michigan - * may be used to endorse or promote products derived from this software - * without specific prior written permission. + * 3. None of the names of McKusick, Ganger, Patt, or the University of + * Michigan may be used to endorse or promote products derived from + * this software without specific prior written permission. * 4. Redistributions in any form must be accompanied by information on * how to obtain complete source code for any accompanying software - * that uses the this software. This source code must either be included + * that uses this software. This source code must either be included * in the distribution or be available for no more than the cost of * distribution plus a nominal fee, and must be freely redistributable * under reasonable conditions. For an executable file, complete @@ -50,7 +52,8 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * - * @(#)softdep.h 9.1 (McKusick) 7/9/97 + * + * from: @(#)softdep.h 9.4 (McKusick) 1/15/98 */ #include <sys/queue.h> @@ -220,6 +223,15 @@ struct pagedep { * The entries on the id_inoupdt and id_newinoupdt lists must be kept * sorted by logical block number to speed the calculation of the size * of the rolled back inode (see explanation in initiate_write_inodeblock). + * When a directory entry is created, it is represented by a diradd. + * The diradd is added to the id_inowait list and is not permitted to be + * written to disk until the inode that it represents is written. After + * the inode is written, the id_inowait list is processed and the diradd + * entries are moved to the id_pendinghd list where they remain until + * the directory block containing the name has been written to disk. + * The purpose of keeping the entries on the id_pendinghd list is so that + * the softdep_fsync function can find and push the inode's directory + * name(s) as part of the fsync operation for that file. */ struct inodedep { struct worklist id_list; /* buffer holding inode block */ |