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author | OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> | 2006-06-23 09:03:26 (GMT) |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-06-23 14:42:49 (GMT) |
commit | 111ebb6e6f7bd7de6d722c5848e95621f43700d9 (patch) | |
tree | bb00b13001db9be201e9b6d31468a79f4d1240bf | |
parent | 4c91c3648c620003cb7b21b8858f36cd6132e168 (diff) | |
download | linux-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>
-rw-r--r-- | fs/cifs/file.c | 24 | ||||
-rw-r--r-- | fs/fs-writeback.c | 4 | ||||
-rw-r--r-- | fs/mpage.c | 22 | ||||
-rw-r--r-- | fs/sync.c | 2 | ||||
-rw-r--r-- | include/linux/kernel.h | 3 | ||||
-rw-r--r-- | include/linux/writeback.h | 5 | ||||
-rw-r--r-- | mm/filemap.c | 6 | ||||
-rw-r--r-- | mm/page-writeback.c | 3 | ||||
-rw-r--r-- | mm/vmscan.c | 2 |
9 files changed, 40 insertions, 31 deletions
diff --git a/fs/cifs/file.c b/fs/cifs/file.c index e2b4ce1..487ea8b 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -1079,9 +1079,9 @@ static int cifs_writepages(struct address_space *mapping, unsigned int bytes_written; struct cifs_sb_info *cifs_sb; int done = 0; - pgoff_t end = -1; + pgoff_t end; pgoff_t index; - int is_range = 0; + int range_whole = 0; struct kvec iov[32]; int len; int n_iov = 0; @@ -1122,16 +1122,14 @@ static int cifs_writepages(struct address_space *mapping, xid = GetXid(); pagevec_init(&pvec, 0); - if (wbc->sync_mode == WB_SYNC_NONE) + if (wbc->range_cyclic) { index = mapping->writeback_index; /* Start from prev offset */ - else { - index = 0; - scanned = 1; - } - if (wbc->start || wbc->end) { - index = wbc->start >> PAGE_CACHE_SHIFT; - end = wbc->end >> PAGE_CACHE_SHIFT; - is_range = 1; + end = -1; + } else { + index = wbc->range_start >> PAGE_CACHE_SHIFT; + end = wbc->range_end >> PAGE_CACHE_SHIFT; + if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) + range_whole = 1; scanned = 1; } retry: @@ -1167,7 +1165,7 @@ retry: break; } - if (unlikely(is_range) && (page->index > end)) { + if (!wbc->range_cyclic && page->index > end) { done = 1; unlock_page(page); break; @@ -1271,7 +1269,7 @@ retry: index = 0; goto retry; } - if (!is_range) + if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) mapping->writeback_index = index; FreeXid(xid); diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index f3fbe2d..6db95cf 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -461,6 +461,8 @@ void sync_inodes_sb(struct super_block *sb, int wait) { struct writeback_control wbc = { .sync_mode = wait ? WB_SYNC_ALL : WB_SYNC_HOLD, + .range_start = 0, + .range_end = LLONG_MAX, }; unsigned long nr_dirty = read_page_state(nr_dirty); unsigned long nr_unstable = read_page_state(nr_unstable); @@ -559,6 +561,8 @@ int write_inode_now(struct inode *inode, int sync) struct writeback_control wbc = { .nr_to_write = LONG_MAX, .sync_mode = WB_SYNC_ALL, + .range_start = 0, + .range_end = LLONG_MAX, }; if (!mapping_cap_writeback_dirty(inode->i_mapping)) @@ -707,9 +707,9 @@ mpage_writepages(struct address_space *mapping, struct pagevec pvec; int nr_pages; pgoff_t index; - pgoff_t end = -1; /* Inclusive */ + pgoff_t end; /* Inclusive */ int scanned = 0; - int is_range = 0; + int range_whole = 0; if (wbc->nonblocking && bdi_write_congested(bdi)) { wbc->encountered_congestion = 1; @@ -721,16 +721,14 @@ mpage_writepages(struct address_space *mapping, writepage = mapping->a_ops->writepage; pagevec_init(&pvec, 0); - if (wbc->sync_mode == WB_SYNC_NONE) { + if (wbc->range_cyclic) { index = mapping->writeback_index; /* Start from prev offset */ + end = -1; } else { - index = 0; /* whole-file sweep */ - scanned = 1; - } - if (wbc->start || wbc->end) { - index = wbc->start >> PAGE_CACHE_SHIFT; - end = wbc->end >> PAGE_CACHE_SHIFT; - is_range = 1; + index = wbc->range_start >> PAGE_CACHE_SHIFT; + end = wbc->range_end >> PAGE_CACHE_SHIFT; + if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) + range_whole = 1; scanned = 1; } retry: @@ -759,7 +757,7 @@ retry: continue; } - if (unlikely(is_range) && page->index > end) { + if (!wbc->range_cyclic && page->index > end) { done = 1; unlock_page(page); continue; @@ -810,7 +808,7 @@ retry: index = 0; goto retry; } - if (!is_range) + if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) mapping->writeback_index = index; if (bio) mpage_bio_submit(WRITE, bio); @@ -100,7 +100,7 @@ asmlinkage long sys_sync_file_range(int fd, loff_t offset, loff_t nbytes, } if (nbytes == 0) - endbyte = -1; + endbyte = LLONG_MAX; else endbyte--; /* inclusive */ diff --git a/include/linux/kernel.h b/include/linux/kernel.h index f4fc576..25fccd8 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -24,6 +24,9 @@ extern const char linux_banner[]; #define LONG_MAX ((long)(~0UL>>1)) #define LONG_MIN (-LONG_MAX - 1) #define ULONG_MAX (~0UL) +#define LLONG_MAX ((long long)(~0ULL>>1)) +#define LLONG_MIN (-LLONG_MAX - 1) +#define ULLONG_MAX (~0ULL) #define STACK_MAGIC 0xdeadbeef diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 56f92fc..9e38b56 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -50,14 +50,15 @@ struct writeback_control { * 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; + loff_t range_start; + loff_t range_end; unsigned nonblocking:1; /* Don't get stuck on request queues */ unsigned encountered_congestion:1; /* An output: a queue is full */ unsigned for_kupdate:1; /* A kupdate writeback */ unsigned for_reclaim:1; /* Invoked from the page allocator */ unsigned for_writepages:1; /* This is a writepages() call */ + unsigned range_cyclic:1; /* range_start is cyclic */ }; /* 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, }; |