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md/bitmap: rename and tidy up BITMAP_PAGE_CLEAN 

The flag 'BITMAP_PAGE_CLEAN' has a confusing name as it doesn't mean
that the page is clean, but rather that there are counters in the page
which allow bits in the bitmap to be cleared - i.e. maybe cleaning can
happen.

So change it to BITMAP_PAGE_PENDING and fix some irregularities:
 - Don't set it in bitmap_init_from_disk as bitmap_set_memory_bits
   sets it when needed
 - in bitmap_daemon_work, if we find a counter that is '1', but
   need_sync is set, then set BITMAP_PAGE_PENDING again (it was
   recently cleared) to ensure we don't forget about this bit.

Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
NeilBrown 2011-09-21 15:37:46 +10:00
parent 01f96c0a99
commit 5a537df44d
1 changed files with 19 additions and 19 deletions
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38
drivers/md/bitmap.c
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@ -868,7 +868,8 @@ static void bitmap_file_kick(struct bitmap *bitmap)
enum bitmap_page_attr {
BITMAP_PAGE_DIRTY = 0, /* there are set bits that need to be synced */
BITMAP_PAGE_CLEAN = 1, /* there are bits that might need to be cleared */
BITMAP_PAGE_PENDING = 1, /* there are bits that are being cleaned.
* i.e. counter is 1 or 2. */
BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
};
@ -1111,7 +1112,6 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
(sector_t)i << CHUNK_BLOCK_SHIFT(bitmap),
needed);
bit_cnt++;
set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
}
}
@ -1204,7 +1204,7 @@ void bitmap_daemon_work(mddev_t *mddev)
if (page != lastpage) {
/* skip this page unless it's marked as needing cleaning */
if (!test_page_attr(bitmap, page, BITMAP_PAGE_CLEAN)) {
if (!test_page_attr(bitmap, page, BITMAP_PAGE_PENDING)) {
int need_write = test_page_attr(bitmap, page,
BITMAP_PAGE_NEEDWRITE);
if (need_write)
@ -1249,19 +1249,17 @@ void bitmap_daemon_work(mddev_t *mddev)
}
spin_lock_irqsave(&bitmap->lock, flags);
if (!bitmap->need_sync)
clear_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
clear_page_attr(bitmap, page, BITMAP_PAGE_PENDING);
}
bmc = bitmap_get_counter(bitmap,
(sector_t)j << CHUNK_BLOCK_SHIFT(bitmap),
&blocks, 0);
if (bmc) {
if (*bmc)
bitmap->allclean = 0;
if (!bmc)
j |= PAGE_COUNTER_MASK;
else if (*bmc) {
bitmap->allclean = 0;
if (*bmc == 2) {
*bmc = 1; /* maybe clear the bit next time */
set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
} else if (*bmc == 1 && !bitmap->need_sync) {
if (*bmc == 1 && !bitmap->need_sync) {
/* we can clear the bit */
*bmc = 0;
bitmap_count_page(bitmap,
@ -1275,13 +1273,15 @@ void bitmap_daemon_work(mddev_t *mddev)
paddr);
else
__clear_bit_le(
file_page_offset(bitmap,
j),
paddr);
file_page_offset(bitmap,
j),
paddr);
kunmap_atomic(paddr, KM_USER0);
} else if (*bmc <= 2) {
*bmc = 1; /* maybe clear the bit next time */
set_page_attr(bitmap, page, BITMAP_PAGE_PENDING);
}
} else
j |= PAGE_COUNTER_MASK;
}
}
spin_unlock_irqrestore(&bitmap->lock, flags);
@ -1458,7 +1458,7 @@ void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long secto
filemap_get_page(
bitmap,
offset >> CHUNK_BLOCK_SHIFT(bitmap)),
BITMAP_PAGE_CLEAN);
BITMAP_PAGE_PENDING);
spin_unlock_irqrestore(&bitmap->lock, flags);
offset += blocks;
@ -1546,7 +1546,7 @@ void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, i
if (*bmc <= 2)
set_page_attr(bitmap,
filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)),
BITMAP_PAGE_CLEAN);
BITMAP_PAGE_PENDING);
}
}
unlock:
@ -1622,7 +1622,7 @@ static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int n
*bmc = 1 | (needed ? NEEDED_MASK : 0);
bitmap_count_page(bitmap, offset, 1);
page = filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap));
set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
set_page_attr(bitmap, page, BITMAP_PAGE_PENDING);
}
spin_unlock_irq(&bitmap->lock);
bitmap->allclean = 0;