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md/bitmap: use set_bit, test_bit, etc for operation on bitmap->flags. 

We currently use '&' and '|' which isn't the norm in the kernel
and doesn't allow easy atomicity.
So change to bit numbers and {set,clear,test}_bit.
This allows us to remove a spinlock/unlock (which was dubious anyway)
and some other simplifications.

Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
NeilBrown 2012-05-22 13:55:15 +10:00
parent 84e923453e
commit b405fe91e5
2 changed files with 24 additions and 28 deletions
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46
drivers/md/bitmap.c
View File

@ -271,7 +271,7 @@ static void write_page(struct bitmap *bitmap, struct page *page, int wait)
if (bitmap->storage.file == NULL) { if (bitmap->storage.file == NULL) {
switch (write_sb_page(bitmap, page, wait)) { switch (write_sb_page(bitmap, page, wait)) {
case -EINVAL: case -EINVAL:
bitmap->flags |= BITMAP_WRITE_ERROR; set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
} }
} else { } else {
@ -289,20 +289,16 @@ static void write_page(struct bitmap *bitmap, struct page *page, int wait)
wait_event(bitmap->write_wait, wait_event(bitmap->write_wait,
atomic_read(&bitmap->pending_writes)==0); atomic_read(&bitmap->pending_writes)==0);
} }
if (bitmap->flags & BITMAP_WRITE_ERROR) if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
bitmap_file_kick(bitmap); bitmap_file_kick(bitmap);
} }
static void end_bitmap_write(struct buffer_head *bh, int uptodate) static void end_bitmap_write(struct buffer_head *bh, int uptodate)
{ {
struct bitmap *bitmap = bh->b_private; struct bitmap *bitmap = bh->b_private;
unsigned long flags;
if (!uptodate) { if (!uptodate)
spin_lock_irqsave(&bitmap->lock, flags); set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
bitmap->flags |= BITMAP_WRITE_ERROR;
spin_unlock_irqrestore(&bitmap->lock, flags);
}
if (atomic_dec_and_test(&bitmap->pending_writes)) if (atomic_dec_and_test(&bitmap->pending_writes))
wake_up(&bitmap->write_wait); wake_up(&bitmap->write_wait);
} }
@ -389,7 +385,7 @@ static int read_page(struct file *file, unsigned long index,
wait_event(bitmap->write_wait, wait_event(bitmap->write_wait,
atomic_read(&bitmap->pending_writes)==0); atomic_read(&bitmap->pending_writes)==0);
if (bitmap->flags & BITMAP_WRITE_ERROR) if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
ret = -EIO; ret = -EIO;
out: out:
if (ret) if (ret)
@ -521,7 +517,7 @@ static int bitmap_new_disk_sb(struct bitmap *bitmap)
memcpy(sb->uuid, bitmap->mddev->uuid, 16); memcpy(sb->uuid, bitmap->mddev->uuid, 16);
bitmap->flags |= BITMAP_STALE; set_bit(BITMAP_STALE, &bitmap->flags);
sb->state = cpu_to_le32(bitmap->flags); sb->state = cpu_to_le32(bitmap->flags);
bitmap->events_cleared = bitmap->mddev->events; bitmap->events_cleared = bitmap->mddev->events;
sb->events_cleared = cpu_to_le64(bitmap->mddev->events); sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
@ -545,7 +541,7 @@ static int bitmap_read_sb(struct bitmap *bitmap)
chunksize = 128 * 1024 * 1024; chunksize = 128 * 1024 * 1024;
daemon_sleep = 5 * HZ; daemon_sleep = 5 * HZ;
write_behind = 0; write_behind = 0;
bitmap->flags = BITMAP_STALE; set_bit(BITMAP_STALE, &bitmap->flags);
err = 0; err = 0;
goto out_no_sb; goto out_no_sb;
} }
@ -617,20 +613,20 @@ static int bitmap_read_sb(struct bitmap *bitmap)
"-- forcing full recovery\n", "-- forcing full recovery\n",
bmname(bitmap), events, bmname(bitmap), events,
(unsigned long long) bitmap->mddev->events); (unsigned long long) bitmap->mddev->events);
bitmap->flags |= BITMAP_STALE; set_bit(BITMAP_STALE, &bitmap->flags);
} }
} }
/* assign fields using values from superblock */ /* assign fields using values from superblock */
bitmap->flags |= le32_to_cpu(sb->state); bitmap->flags |= le32_to_cpu(sb->state);
if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN) if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
bitmap->flags |= BITMAP_HOSTENDIAN; set_bit(BITMAP_HOSTENDIAN, &bitmap->flags);
bitmap->events_cleared = le64_to_cpu(sb->events_cleared); bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
err = 0; err = 0;
out: out:
kunmap_atomic(sb); kunmap_atomic(sb);
out_no_sb: out_no_sb:
if (bitmap->flags & BITMAP_STALE) if (test_bit(BITMAP_STALE, &bitmap->flags))
bitmap->events_cleared = bitmap->mddev->events; bitmap->events_cleared = bitmap->mddev->events;
bitmap->mddev->bitmap_info.chunksize = chunksize; bitmap->mddev->bitmap_info.chunksize = chunksize;
bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep; bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
@ -796,8 +792,7 @@ static void bitmap_file_kick(struct bitmap *bitmap)
{ {
char *path, *ptr = NULL; char *path, *ptr = NULL;
if (!(bitmap->flags & BITMAP_STALE)) { if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
bitmap->flags |= BITMAP_STALE;
bitmap_update_sb(bitmap); bitmap_update_sb(bitmap);
if (bitmap->storage.file) { if (bitmap->storage.file) {
@ -868,7 +863,7 @@ static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
/* set the bit */ /* set the bit */
kaddr = kmap_atomic(page); kaddr = kmap_atomic(page);
if (bitmap->flags & BITMAP_HOSTENDIAN) if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
set_bit(bit, kaddr); set_bit(bit, kaddr);
else else
__set_bit_le(bit, kaddr); __set_bit_le(bit, kaddr);
@ -890,7 +885,7 @@ static void bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
return; return;
bit = file_page_offset(&bitmap->storage, chunk); bit = file_page_offset(&bitmap->storage, chunk);
paddr = kmap_atomic(page); paddr = kmap_atomic(page);
if (bitmap->flags & BITMAP_HOSTENDIAN) if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
clear_bit(bit, paddr); clear_bit(bit, paddr);
else else
__clear_bit_le(bit, paddr); __clear_bit_le(bit, paddr);
@ -941,7 +936,7 @@ void bitmap_unplug(struct bitmap *bitmap)
else else
md_super_wait(bitmap->mddev); md_super_wait(bitmap->mddev);
} }
if (bitmap->flags & BITMAP_WRITE_ERROR) if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
bitmap_file_kick(bitmap); bitmap_file_kick(bitmap);
} }
EXPORT_SYMBOL(bitmap_unplug); EXPORT_SYMBOL(bitmap_unplug);
@ -988,7 +983,7 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
return 0; return 0;
} }
outofdate = bitmap->flags & BITMAP_STALE; outofdate = test_bit(BITMAP_STALE, &bitmap->flags);
if (outofdate) if (outofdate)
printk(KERN_INFO "%s: bitmap file is out of date, doing full " printk(KERN_INFO "%s: bitmap file is out of date, doing full "
"recovery\n", bmname(bitmap)); "recovery\n", bmname(bitmap));
@ -1045,12 +1040,13 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
write_page(bitmap, page, 1); write_page(bitmap, page, 1);
ret = -EIO; ret = -EIO;
if (bitmap->flags & BITMAP_WRITE_ERROR) if (test_bit(BITMAP_WRITE_ERROR,
&bitmap->flags))
goto err; goto err;
} }
} }
paddr = kmap_atomic(page); paddr = kmap_atomic(page);
if (bitmap->flags & BITMAP_HOSTENDIAN) if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
b = test_bit(bit, paddr); b = test_bit(bit, paddr);
else else
b = test_bit_le(bit, paddr); b = test_bit_le(bit, paddr);
@ -1758,7 +1754,7 @@ int bitmap_create(struct mddev *mddev)
mddev->bitmap = bitmap; mddev->bitmap = bitmap;
return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0; return test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
error: error:
bitmap_free(bitmap); bitmap_free(bitmap);
@ -1799,7 +1795,7 @@ int bitmap_load(struct mddev *mddev)
if (err) if (err)
goto out; goto out;
bitmap->flags &= ~BITMAP_STALE; clear_bit(BITMAP_STALE, &bitmap->flags);
/* Kick recovery in case any bits were set */ /* Kick recovery in case any bits were set */
set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery); set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
@ -1809,7 +1805,7 @@ int bitmap_load(struct mddev *mddev)
bitmap_update_sb(bitmap); bitmap_update_sb(bitmap);
if (bitmap->flags & BITMAP_WRITE_ERROR) if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
err = -EIO; err = -EIO;
out: out:
return err; return err;

6
drivers/md/bitmap.h
View File

@ -111,9 +111,9 @@ typedef __u16 bitmap_counter_t;
/* use these for bitmap->flags and bitmap->sb->state bit-fields */ /* use these for bitmap->flags and bitmap->sb->state bit-fields */
enum bitmap_state { enum bitmap_state {
BITMAP_STALE = 0x002, /* the bitmap file is out of date or had -EIO */ BITMAP_STALE = 1, /* the bitmap file is out of date or had -EIO */
BITMAP_WRITE_ERROR = 0x004, /* A write error has occurred */ BITMAP_WRITE_ERROR = 2, /* A write error has occurred */
BITMAP_HOSTENDIAN = 0x8000, BITMAP_HOSTENDIAN =15,
}; };
/* the superblock at the front of the bitmap file -- little endian */ /* the superblock at the front of the bitmap file -- little endian */