md: change bitmap_unplug and others to void functions

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>

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index ae94f3b..927cb34 100644 (file)
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -305,10 +305,11 @@ 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;
 
@@ -316,27 +317,26 @@ static int write_page(struct bitmap *bitmap, struct page *page, int wait)
                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)
@@ -456,17 +456,17 @@ out:
  */
 
 /* 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);
@@ -474,7 +474,7 @@ int bitmap_update_sb(struct bitmap *bitmap)
        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 */
@@ -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;
@@ -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;
 }
 
 /*
@@ -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);
@@ -800,16 +808,15 @@ 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 */
@@ -817,7 +824,7 @@ int bitmap_unplug(struct bitmap *bitmap)
                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);
@@ -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)
@@ -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);
@@ -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;
 
@@ -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;
@@ -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;
                                }
                        }
 
@@ -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;
 }
 
@@ -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++) {
@@ -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;
                        }
 
@@ -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;
@@ -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,
@@ -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);

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 36c05ba..65ddc88 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -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;
@@ -1727,7 +1726,7 @@ repeat:
                "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: ");

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 46677d7..00c78b7 100644 (file)
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -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;

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 9eb66c1..a95ada1 100644 (file)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -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;

diff --git a/include/linux/raid/bitmap.h b/include/linux/raid/bitmap.h
index dd5a05d..75e17a0 100644 (file)
--- a/include/linux/raid/bitmap.h
+++ b/include/linux/raid/bitmap.h
@@ -262,7 +262,7 @@ int  bitmap_active(struct bitmap *bitmap);
 
 char *file_path(struct file *file, char *buf, int count);
 void bitmap_print_sb(struct bitmap *bitmap);
-int bitmap_update_sb(struct bitmap *bitmap);
+void bitmap_update_sb(struct bitmap *bitmap);
 
 int  bitmap_setallbits(struct bitmap *bitmap);
 void bitmap_write_all(struct bitmap *bitmap);
@@ -278,8 +278,8 @@ int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int d
 void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int aborted);
 void bitmap_close_sync(struct bitmap *bitmap);
 
-int bitmap_unplug(struct bitmap *bitmap);
-int bitmap_daemon_work(struct bitmap *bitmap);
+void bitmap_unplug(struct bitmap *bitmap);
+void bitmap_daemon_work(struct bitmap *bitmap);
 #endif
 
 #endif