diff options
| author | Andrew Morton <akpm@osdl.org> | 2004-08-22 22:59:27 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2004-08-22 22:59:27 -0700 |
| commit | f07812ca2925f6dc6027883ab15891781dba4827 (patch) | |
| tree | e12f1eb2d11cb984b9f9c71801e1b0b75cd812bf /include/linux | |
| parent | d4f9d02b9151b9ff87a950ed42220de4f740d27b (diff) | |
[PATCH] Writeback page range hint
Modify mpage_writepages to optionally only write back dirty pages within a
specified range in a file (as in the case of O_SYNC). Cheat a little to avoid
changes to prototypes of aops - just put the <start, end> hint into the
writeback_control struct instead. If <start, end> are not set, then default
to writing back all the mapping's dirty pages.
Signed-off-by: Suparna Bhattacharya <suparna@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/writeback.h | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/include/linux/writeback.h b/include/linux/writeback.h index e4450070ac78..48d95e59230b 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -29,7 +29,9 @@ enum writeback_sync_modes { }; /* - * A control structure which tells the writeback code what to do + * A control structure which tells the writeback code what to do. These are + * always on the stack, and hence need no locking. They are always initialised + * in a manner such that unspecified fields are set to zero. */ struct writeback_control { struct backing_dev_info *bdi; /* If !NULL, only write back this @@ -40,10 +42,19 @@ struct writeback_control { long nr_to_write; /* Write this many pages, and decrement this for each page written */ long pages_skipped; /* Pages which were not written */ - int nonblocking; /* Don't get stuck on request queues */ - int encountered_congestion; /* An output: a queue is full */ - int for_kupdate; /* A kupdate writeback */ - int for_reclaim; /* Invoked from the page allocator */ + + /* + * For a_ops->writepages(): is start or end are non-zero then this is + * a hint that the filesystem need only write out the pages inside that + * byterange. The byte at `end' is included in the writeout request. + */ + loff_t start; + loff_t end; + + int nonblocking:1; /* Don't get stuck on request queues */ + int encountered_congestion:1; /* An output: a queue is full */ + int for_kupdate:1; /* A kupdate writeback */ + int for_reclaim:1; /* Invoked from the page allocator */ }; /* |