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author | OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> | 2006-06-23 09:03:26 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-06-23 14:42:49 (GMT) |
commit | 111ebb6e6f7bd7de6d722c5848e95621f43700d9 (patch) | |
tree | bb00b13001db9be201e9b6d31468a79f4d1240bf /mm | |
parent | 4c91c3648c620003cb7b21b8858f36cd6132e168 (diff) | |
download | linux-fsl-qoriq-111ebb6e6f7bd7de6d722c5848e95621f43700d9.tar.xz |
[PATCH] writeback: fix range handling
When a writeback_control's `start' and `end' fields are used to
indicate a one-byte-range starting at file offset zero, the required
values of .start=0,.end=0 mean that the ->writepages() implementation
has no way of telling that it is being asked to perform a range
request. Because we're currently overloading (start == 0 && end == 0)
to mean "this is not a write-a-range request".
To make all this sane, the patch changes range of writeback_control.
So caller does: If it is calling ->writepages() to write pages, it
sets range (range_start/end or range_cyclic) always.
And if range_cyclic is true, ->writepages() thinks the range is
cyclic, otherwise it just uses range_start and range_end.
This patch does,
- Add LLONG_MAX, LLONG_MIN, ULLONG_MAX to include/linux/kernel.h
-1 is usually ok for range_end (type is long long). But, if someone did,
range_end += val; range_end is "val - 1"
u64val = range_end >> bits; u64val is "~(0ULL)"
or something, they are wrong. So, this adds LLONG_MAX to avoid nasty
things, and uses LLONG_MAX for range_end.
- All callers of ->writepages() sets range_start/end or range_cyclic.
- Fix updates of ->writeback_index. It seems already bit strange.
If it starts at 0 and ended by check of nr_to_write, this last
index may reduce chance to scan end of file. So, this updates
->writeback_index only if range_cyclic is true or whole-file is
scanned.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Steven French <sfrench@us.ibm.com>
Cc: "Vladimir V. Saveliev" <vs@namesys.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/filemap.c | 6 | ||||
-rw-r--r-- | mm/page-writeback.c | 3 | ||||
-rw-r--r-- | mm/vmscan.c | 2 |
3 files changed, 8 insertions, 3 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index fd57442..3342067 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -190,8 +190,8 @@ int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start, struct writeback_control wbc = { .sync_mode = sync_mode, .nr_to_write = mapping->nrpages * 2, - .start = start, - .end = end, + .range_start = start, + .range_end = end, }; if (!mapping_cap_writeback_dirty(mapping)) @@ -204,7 +204,7 @@ int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start, static inline int __filemap_fdatawrite(struct address_space *mapping, int sync_mode) { - return __filemap_fdatawrite_range(mapping, 0, 0, sync_mode); + return __filemap_fdatawrite_range(mapping, 0, LLONG_MAX, sync_mode); } int filemap_fdatawrite(struct address_space *mapping) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 75d7f48..8ccf6f1b 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -204,6 +204,7 @@ static void balance_dirty_pages(struct address_space *mapping) .sync_mode = WB_SYNC_NONE, .older_than_this = NULL, .nr_to_write = write_chunk, + .range_cyclic = 1, }; get_dirty_limits(&wbs, &background_thresh, @@ -331,6 +332,7 @@ static void background_writeout(unsigned long _min_pages) .older_than_this = NULL, .nr_to_write = 0, .nonblocking = 1, + .range_cyclic = 1, }; for ( ; ; ) { @@ -407,6 +409,7 @@ static void wb_kupdate(unsigned long arg) .nr_to_write = 0, .nonblocking = 1, .for_kupdate = 1, + .range_cyclic = 1, }; sync_supers(); diff --git a/mm/vmscan.c b/mm/vmscan.c index 46be8a0..bc5d4f4 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -339,6 +339,8 @@ pageout_t pageout(struct page *page, struct address_space *mapping) struct writeback_control wbc = { .sync_mode = WB_SYNC_NONE, .nr_to_write = SWAP_CLUSTER_MAX, + .range_start = 0, + .range_end = LLONG_MAX, .nonblocking = 1, .for_reclaim = 1, }; |