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md: change bitmap_unplug and others to void functions
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bitmap_unplug only ever returns 0, so it may as well be void.  Two callers try
to print a message if it returns non-zero, but that message is already printed
by bitmap_file_kick.

write_page returns an error which is not consistently checked.  It always
causes BITMAP_WRITE_ERROR to be set on an error, and that can more
conveniently be checked.

When the return of write_page is checked, an error causes bitmap_file_kick to
be called - so move that call into write_page - and protect against recursive
calls into bitmap_file_kick.

bitmap_update_sb returns an error that is never checked.

So make these 'void' and be consistent about checking the bit.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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NeilBrown authored and Linus Torvalds committed Jul 17, 2007
1 parent f0d76d7 commit 4ad1366
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Showing 5 changed files with 78 additions and 77 deletions.
140 changes: 72 additions & 68 deletions drivers/md/bitmap.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -305,38 +305,38 @@ static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
return 0;
}

static void bitmap_file_kick(struct bitmap *bitmap);
/*
* write out a page to a file
*/
static int write_page(struct bitmap *bitmap, struct page *page, int wait)
static void write_page(struct bitmap *bitmap, struct page *page, int wait)
{
struct buffer_head *bh;

if (bitmap->file == NULL) {
switch (write_sb_page(bitmap, page, wait)) {
case -EINVAL:
bitmap->flags |= BITMAP_WRITE_ERROR;
return -EIO;
}
return 0;
}
} else {

bh = page_buffers(page);
bh = page_buffers(page);

while (bh && bh->b_blocknr) {
atomic_inc(&bitmap->pending_writes);
set_buffer_locked(bh);
set_buffer_mapped(bh);
submit_bh(WRITE, bh);
bh = bh->b_this_page;
}
while (bh && bh->b_blocknr) {
atomic_inc(&bitmap->pending_writes);
set_buffer_locked(bh);
set_buffer_mapped(bh);
submit_bh(WRITE, bh);
bh = bh->b_this_page;
}

if (wait) {
wait_event(bitmap->write_wait,
atomic_read(&bitmap->pending_writes)==0);
return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0;
if (wait) {
wait_event(bitmap->write_wait,
atomic_read(&bitmap->pending_writes)==0);
}
}
return 0;
if (bitmap->flags & BITMAP_WRITE_ERROR)
bitmap_file_kick(bitmap);
}

static void end_bitmap_write(struct buffer_head *bh, int uptodate)
Expand Down Expand Up @@ -456,25 +456,25 @@ static struct page *read_page(struct file *file, unsigned long index,
*/

/* update the event counter and sync the superblock to disk */
int bitmap_update_sb(struct bitmap *bitmap)
void bitmap_update_sb(struct bitmap *bitmap)
{
bitmap_super_t *sb;
unsigned long flags;

if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
return 0;
return;
spin_lock_irqsave(&bitmap->lock, flags);
if (!bitmap->sb_page) { /* no superblock */
spin_unlock_irqrestore(&bitmap->lock, flags);
return 0;
return;
}
spin_unlock_irqrestore(&bitmap->lock, flags);
sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
sb->events = cpu_to_le64(bitmap->mddev->events);
if (!bitmap->mddev->degraded)
sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
kunmap_atomic(sb, KM_USER0);
return write_page(bitmap, bitmap->sb_page, 1);
write_page(bitmap, bitmap->sb_page, 1);
}

/* print out the bitmap file superblock */
Expand Down Expand Up @@ -603,20 +603,22 @@ enum bitmap_mask_op {
MASK_UNSET
};

/* record the state of the bitmap in the superblock */
static void bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits,
enum bitmap_mask_op op)
/* record the state of the bitmap in the superblock. Return the old value */
static int bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits,
enum bitmap_mask_op op)
{
bitmap_super_t *sb;
unsigned long flags;
int old;

spin_lock_irqsave(&bitmap->lock, flags);
if (!bitmap->sb_page) { /* can't set the state */
spin_unlock_irqrestore(&bitmap->lock, flags);
return;
return 0;
}
spin_unlock_irqrestore(&bitmap->lock, flags);
sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
old = le32_to_cpu(sb->state) & bits;
switch (op) {
case MASK_SET: sb->state |= cpu_to_le32(bits);
break;
Expand All @@ -625,6 +627,7 @@ static void bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits,
default: BUG();
}
kunmap_atomic(sb, KM_USER0);
return old;
}

/*
Expand Down Expand Up @@ -718,18 +721,23 @@ static void bitmap_file_kick(struct bitmap *bitmap)
{
char *path, *ptr = NULL;

bitmap_mask_state(bitmap, BITMAP_STALE, MASK_SET);
bitmap_update_sb(bitmap);
if (bitmap_mask_state(bitmap, BITMAP_STALE, MASK_SET) == 0) {
bitmap_update_sb(bitmap);

if (bitmap->file) {
path = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (path)
ptr = file_path(bitmap->file, path, PAGE_SIZE);
if (bitmap->file) {
path = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (path)
ptr = file_path(bitmap->file, path, PAGE_SIZE);

printk(KERN_ALERT "%s: kicking failed bitmap file %s from array!\n",
bmname(bitmap), ptr ? ptr : "");
printk(KERN_ALERT
"%s: kicking failed bitmap file %s from array!\n",
bmname(bitmap), ptr ? ptr : "");

kfree(path);
kfree(path);
} else
printk(KERN_ALERT
"%s: disabling internal bitmap due to errors\n",
bmname(bitmap));
}

bitmap_file_put(bitmap);
Expand Down Expand Up @@ -800,24 +808,23 @@ static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
/* this gets called when the md device is ready to unplug its underlying
* (slave) device queues -- before we let any writes go down, we need to
* sync the dirty pages of the bitmap file to disk */
int bitmap_unplug(struct bitmap *bitmap)
void bitmap_unplug(struct bitmap *bitmap)
{
unsigned long i, flags;
int dirty, need_write;
struct page *page;
int wait = 0;
int err;

if (!bitmap)
return 0;
return;

/* look at each page to see if there are any set bits that need to be
* flushed out to disk */
for (i = 0; i < bitmap->file_pages; i++) {
spin_lock_irqsave(&bitmap->lock, flags);
if (!bitmap->filemap) {
spin_unlock_irqrestore(&bitmap->lock, flags);
return 0;
return;
}
page = bitmap->filemap[i];
dirty = test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
Expand All @@ -829,7 +836,7 @@ int bitmap_unplug(struct bitmap *bitmap)
spin_unlock_irqrestore(&bitmap->lock, flags);

if (dirty | need_write)
err = write_page(bitmap, page, 0);
write_page(bitmap, page, 0);
}
if (wait) { /* if any writes were performed, we need to wait on them */
if (bitmap->file)
Expand All @@ -840,7 +847,6 @@ int bitmap_unplug(struct bitmap *bitmap)
}
if (bitmap->flags & BITMAP_WRITE_ERROR)
bitmap_file_kick(bitmap);
return 0;
}

static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
Expand Down Expand Up @@ -889,21 +895,21 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
bmname(bitmap),
(unsigned long) i_size_read(file->f_mapping->host),
bytes + sizeof(bitmap_super_t));
goto out;
goto err;
}

ret = -ENOMEM;

bitmap->filemap = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
if (!bitmap->filemap)
goto out;
goto err;

/* We need 4 bits per page, rounded up to a multiple of sizeof(unsigned long) */
bitmap->filemap_attr = kzalloc(
roundup( DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
GFP_KERNEL);
if (!bitmap->filemap_attr)
goto out;
goto err;

oldindex = ~0L;

Expand Down Expand Up @@ -936,7 +942,7 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
}
if (IS_ERR(page)) { /* read error */
ret = PTR_ERR(page);
goto out;
goto err;
}

oldindex = index;
Expand All @@ -951,11 +957,13 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
memset(paddr + offset, 0xff,
PAGE_SIZE - offset);
kunmap_atomic(paddr, KM_USER0);
ret = write_page(bitmap, page, 1);
if (ret) {
write_page(bitmap, page, 1);

ret = -EIO;
if (bitmap->flags & BITMAP_WRITE_ERROR) {
/* release, page not in filemap yet */
put_page(page);
goto out;
goto err;
}
}

Expand Down Expand Up @@ -987,11 +995,15 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
md_wakeup_thread(bitmap->mddev->thread);
}

out:
printk(KERN_INFO "%s: bitmap initialized from disk: "
"read %lu/%lu pages, set %lu bits, status: %d\n",
bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt, ret);
"read %lu/%lu pages, set %lu bits\n",
bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt);

return 0;

err:
printk(KERN_INFO "%s: bitmap initialisation failed: %d\n",
bmname(bitmap), ret);
return ret;
}

Expand Down Expand Up @@ -1028,19 +1040,18 @@ static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
* out to disk
*/

int bitmap_daemon_work(struct bitmap *bitmap)
void bitmap_daemon_work(struct bitmap *bitmap)
{
unsigned long j;
unsigned long flags;
struct page *page = NULL, *lastpage = NULL;
int err = 0;
int blocks;
void *paddr;

if (bitmap == NULL)
return 0;
return;
if (time_before(jiffies, bitmap->daemon_lastrun + bitmap->daemon_sleep*HZ))
return 0;
return;
bitmap->daemon_lastrun = jiffies;

for (j = 0; j < bitmap->chunks; j++) {
Expand All @@ -1063,14 +1074,8 @@ int bitmap_daemon_work(struct bitmap *bitmap)
clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);

spin_unlock_irqrestore(&bitmap->lock, flags);
if (need_write) {
switch (write_page(bitmap, page, 0)) {
case 0:
break;
default:
bitmap_file_kick(bitmap);
}
}
if (need_write)
write_page(bitmap, page, 0);
continue;
}

Expand All @@ -1079,13 +1084,11 @@ int bitmap_daemon_work(struct bitmap *bitmap)
if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
spin_unlock_irqrestore(&bitmap->lock, flags);
err = write_page(bitmap, lastpage, 0);
write_page(bitmap, lastpage, 0);
} else {
set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
spin_unlock_irqrestore(&bitmap->lock, flags);
}
if (err)
bitmap_file_kick(bitmap);
} else
spin_unlock_irqrestore(&bitmap->lock, flags);
lastpage = page;
Expand Down Expand Up @@ -1128,14 +1131,13 @@ int bitmap_daemon_work(struct bitmap *bitmap)
if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
spin_unlock_irqrestore(&bitmap->lock, flags);
err = write_page(bitmap, lastpage, 0);
write_page(bitmap, lastpage, 0);
} else {
set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
spin_unlock_irqrestore(&bitmap->lock, flags);
}
}

return err;
}

static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
Expand Down Expand Up @@ -1548,7 +1550,9 @@ int bitmap_create(mddev_t *mddev)

mddev->thread->timeout = bitmap->daemon_sleep * HZ;

return bitmap_update_sb(bitmap);
bitmap_update_sb(bitmap);

return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0;

error:
bitmap_free(bitmap);
Expand Down
3 changes: 1 addition & 2 deletions drivers/md/md.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1640,7 +1640,6 @@ static void sync_sbs(mddev_t * mddev, int nospares)

static void md_update_sb(mddev_t * mddev, int force_change)
{
int err;
struct list_head *tmp;
mdk_rdev_t *rdev;
int sync_req;
Expand Down Expand Up @@ -1727,7 +1726,7 @@ static void md_update_sb(mddev_t * mddev, int force_change)
"md: updating %s RAID superblock on device (in sync %d)\n",
mdname(mddev),mddev->in_sync);

err = bitmap_update_sb(mddev->bitmap);
bitmap_update_sb(mddev->bitmap);
ITERATE_RDEV(mddev,rdev,tmp) {
char b[BDEVNAME_SIZE];
dprintk(KERN_INFO "md: ");
Expand Down
3 changes: 1 addition & 2 deletions drivers/md/raid1.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1526,8 +1526,7 @@ static void raid1d(mddev_t *mddev)
blk_remove_plug(mddev->queue);
spin_unlock_irqrestore(&conf->device_lock, flags);
/* flush any pending bitmap writes to disk before proceeding w/ I/O */
if (bitmap_unplug(mddev->bitmap) != 0)
printk("%s: bitmap file write failed!\n", mdname(mddev));
bitmap_unplug(mddev->bitmap);

while (bio) { /* submit pending writes */
struct bio *next = bio->bi_next;
Expand Down
3 changes: 1 addition & 2 deletions drivers/md/raid10.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1510,8 +1510,7 @@ static void raid10d(mddev_t *mddev)
blk_remove_plug(mddev->queue);
spin_unlock_irqrestore(&conf->device_lock, flags);
/* flush any pending bitmap writes to disk before proceeding w/ I/O */
if (bitmap_unplug(mddev->bitmap) != 0)
printk("%s: bitmap file write failed!\n", mdname(mddev));
bitmap_unplug(mddev->bitmap);

while (bio) { /* submit pending writes */
struct bio *next = bio->bi_next;
Expand Down
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