fs: move bdev code out of buffer.c
Nick Piggin [Wed, 25 Feb 2009 09:44:19 +0000 (10:44 +0100)]
Move some block device related code out from buffer.c and put it in
block_dev.c. I'm trying to move non-buffer_head code out of buffer.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/block_dev.c
fs/buffer.c
include/linux/buffer_head.h
include/linux/fs.h

index b3c1eff..8c3c689 100644 (file)
@@ -18,6 +18,7 @@
 #include <linux/module.h>
 #include <linux/blkpg.h>
 #include <linux/buffer_head.h>
+#include <linux/pagevec.h>
 #include <linux/writeback.h>
 #include <linux/mpage.h>
 #include <linux/mount.h>
@@ -174,6 +175,151 @@ blkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
                                iov, offset, nr_segs, blkdev_get_blocks, NULL);
 }
 
+/*
+ * Write out and wait upon all the dirty data associated with a block
+ * device via its mapping.  Does not take the superblock lock.
+ */
+int sync_blockdev(struct block_device *bdev)
+{
+       int ret = 0;
+
+       if (bdev)
+               ret = filemap_write_and_wait(bdev->bd_inode->i_mapping);
+       return ret;
+}
+EXPORT_SYMBOL(sync_blockdev);
+
+/*
+ * Write out and wait upon all dirty data associated with this
+ * device.   Filesystem data as well as the underlying block
+ * device.  Takes the superblock lock.
+ */
+int fsync_bdev(struct block_device *bdev)
+{
+       struct super_block *sb = get_super(bdev);
+       if (sb) {
+               int res = fsync_super(sb);
+               drop_super(sb);
+               return res;
+       }
+       return sync_blockdev(bdev);
+}
+
+/**
+ * freeze_bdev  --  lock a filesystem and force it into a consistent state
+ * @bdev:      blockdevice to lock
+ *
+ * This takes the block device bd_mount_sem to make sure no new mounts
+ * happen on bdev until thaw_bdev() is called.
+ * If a superblock is found on this device, we take the s_umount semaphore
+ * on it to make sure nobody unmounts until the snapshot creation is done.
+ * The reference counter (bd_fsfreeze_count) guarantees that only the last
+ * unfreeze process can unfreeze the frozen filesystem actually when multiple
+ * freeze requests arrive simultaneously. It counts up in freeze_bdev() and
+ * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze
+ * actually.
+ */
+struct super_block *freeze_bdev(struct block_device *bdev)
+{
+       struct super_block *sb;
+       int error = 0;
+
+       mutex_lock(&bdev->bd_fsfreeze_mutex);
+       if (bdev->bd_fsfreeze_count > 0) {
+               bdev->bd_fsfreeze_count++;
+               sb = get_super(bdev);
+               mutex_unlock(&bdev->bd_fsfreeze_mutex);
+               return sb;
+       }
+       bdev->bd_fsfreeze_count++;
+
+       down(&bdev->bd_mount_sem);
+       sb = get_super(bdev);
+       if (sb && !(sb->s_flags & MS_RDONLY)) {
+               sb->s_frozen = SB_FREEZE_WRITE;
+               smp_wmb();
+
+               __fsync_super(sb);
+
+               sb->s_frozen = SB_FREEZE_TRANS;
+               smp_wmb();
+
+               sync_blockdev(sb->s_bdev);
+
+               if (sb->s_op->freeze_fs) {
+                       error = sb->s_op->freeze_fs(sb);
+                       if (error) {
+                               printk(KERN_ERR
+                                       "VFS:Filesystem freeze failed\n");
+                               sb->s_frozen = SB_UNFROZEN;
+                               drop_super(sb);
+                               up(&bdev->bd_mount_sem);
+                               bdev->bd_fsfreeze_count--;
+                               mutex_unlock(&bdev->bd_fsfreeze_mutex);
+                               return ERR_PTR(error);
+                       }
+               }
+       }
+
+       sync_blockdev(bdev);
+       mutex_unlock(&bdev->bd_fsfreeze_mutex);
+
+       return sb;      /* thaw_bdev releases s->s_umount and bd_mount_sem */
+}
+EXPORT_SYMBOL(freeze_bdev);
+
+/**
+ * thaw_bdev  -- unlock filesystem
+ * @bdev:      blockdevice to unlock
+ * @sb:                associated superblock
+ *
+ * Unlocks the filesystem and marks it writeable again after freeze_bdev().
+ */
+int thaw_bdev(struct block_device *bdev, struct super_block *sb)
+{
+       int error = 0;
+
+       mutex_lock(&bdev->bd_fsfreeze_mutex);
+       if (!bdev->bd_fsfreeze_count) {
+               mutex_unlock(&bdev->bd_fsfreeze_mutex);
+               return -EINVAL;
+       }
+
+       bdev->bd_fsfreeze_count--;
+       if (bdev->bd_fsfreeze_count > 0) {
+               if (sb)
+                       drop_super(sb);
+               mutex_unlock(&bdev->bd_fsfreeze_mutex);
+               return 0;
+       }
+
+       if (sb) {
+               BUG_ON(sb->s_bdev != bdev);
+               if (!(sb->s_flags & MS_RDONLY)) {
+                       if (sb->s_op->unfreeze_fs) {
+                               error = sb->s_op->unfreeze_fs(sb);
+                               if (error) {
+                                       printk(KERN_ERR
+                                               "VFS:Filesystem thaw failed\n");
+                                       sb->s_frozen = SB_FREEZE_TRANS;
+                                       bdev->bd_fsfreeze_count++;
+                                       mutex_unlock(&bdev->bd_fsfreeze_mutex);
+                                       return error;
+                               }
+                       }
+                       sb->s_frozen = SB_UNFROZEN;
+                       smp_wmb();
+                       wake_up(&sb->s_wait_unfrozen);
+               }
+               drop_super(sb);
+       }
+
+       up(&bdev->bd_mount_sem);
+       mutex_unlock(&bdev->bd_fsfreeze_mutex);
+       return 0;
+}
+EXPORT_SYMBOL(thaw_bdev);
+
 static int blkdev_writepage(struct page *page, struct writeback_control *wbc)
 {
        return block_write_full_page(page, blkdev_get_block, wbc);
index 891e1c7..a2fd743 100644 (file)
@@ -166,151 +166,6 @@ void end_buffer_write_sync(struct buffer_head *bh, int uptodate)
 }
 
 /*
- * Write out and wait upon all the dirty data associated with a block
- * device via its mapping.  Does not take the superblock lock.
- */
-int sync_blockdev(struct block_device *bdev)
-{
-       int ret = 0;
-
-       if (bdev)
-               ret = filemap_write_and_wait(bdev->bd_inode->i_mapping);
-       return ret;
-}
-EXPORT_SYMBOL(sync_blockdev);
-
-/*
- * Write out and wait upon all dirty data associated with this
- * device.   Filesystem data as well as the underlying block
- * device.  Takes the superblock lock.
- */
-int fsync_bdev(struct block_device *bdev)
-{
-       struct super_block *sb = get_super(bdev);
-       if (sb) {
-               int res = fsync_super(sb);
-               drop_super(sb);
-               return res;
-       }
-       return sync_blockdev(bdev);
-}
-
-/**
- * freeze_bdev  --  lock a filesystem and force it into a consistent state
- * @bdev:      blockdevice to lock
- *
- * This takes the block device bd_mount_sem to make sure no new mounts
- * happen on bdev until thaw_bdev() is called.
- * If a superblock is found on this device, we take the s_umount semaphore
- * on it to make sure nobody unmounts until the snapshot creation is done.
- * The reference counter (bd_fsfreeze_count) guarantees that only the last
- * unfreeze process can unfreeze the frozen filesystem actually when multiple
- * freeze requests arrive simultaneously. It counts up in freeze_bdev() and
- * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze
- * actually.
- */
-struct super_block *freeze_bdev(struct block_device *bdev)
-{
-       struct super_block *sb;
-       int error = 0;
-
-       mutex_lock(&bdev->bd_fsfreeze_mutex);
-       if (bdev->bd_fsfreeze_count > 0) {
-               bdev->bd_fsfreeze_count++;
-               sb = get_super(bdev);
-               mutex_unlock(&bdev->bd_fsfreeze_mutex);
-               return sb;
-       }
-       bdev->bd_fsfreeze_count++;
-
-       down(&bdev->bd_mount_sem);
-       sb = get_super(bdev);
-       if (sb && !(sb->s_flags & MS_RDONLY)) {
-               sb->s_frozen = SB_FREEZE_WRITE;
-               smp_wmb();
-
-               __fsync_super(sb);
-
-               sb->s_frozen = SB_FREEZE_TRANS;
-               smp_wmb();
-
-               sync_blockdev(sb->s_bdev);
-
-               if (sb->s_op->freeze_fs) {
-                       error = sb->s_op->freeze_fs(sb);
-                       if (error) {
-                               printk(KERN_ERR
-                                       "VFS:Filesystem freeze failed\n");
-                               sb->s_frozen = SB_UNFROZEN;
-                               drop_super(sb);
-                               up(&bdev->bd_mount_sem);
-                               bdev->bd_fsfreeze_count--;
-                               mutex_unlock(&bdev->bd_fsfreeze_mutex);
-                               return ERR_PTR(error);
-                       }
-               }
-       }
-
-       sync_blockdev(bdev);
-       mutex_unlock(&bdev->bd_fsfreeze_mutex);
-
-       return sb;      /* thaw_bdev releases s->s_umount and bd_mount_sem */
-}
-EXPORT_SYMBOL(freeze_bdev);
-
-/**
- * thaw_bdev  -- unlock filesystem
- * @bdev:      blockdevice to unlock
- * @sb:                associated superblock
- *
- * Unlocks the filesystem and marks it writeable again after freeze_bdev().
- */
-int thaw_bdev(struct block_device *bdev, struct super_block *sb)
-{
-       int error = 0;
-
-       mutex_lock(&bdev->bd_fsfreeze_mutex);
-       if (!bdev->bd_fsfreeze_count) {
-               mutex_unlock(&bdev->bd_fsfreeze_mutex);
-               return -EINVAL;
-       }
-
-       bdev->bd_fsfreeze_count--;
-       if (bdev->bd_fsfreeze_count > 0) {
-               if (sb)
-                       drop_super(sb);
-               mutex_unlock(&bdev->bd_fsfreeze_mutex);
-               return 0;
-       }
-
-       if (sb) {
-               BUG_ON(sb->s_bdev != bdev);
-               if (!(sb->s_flags & MS_RDONLY)) {
-                       if (sb->s_op->unfreeze_fs) {
-                               error = sb->s_op->unfreeze_fs(sb);
-                               if (error) {
-                                       printk(KERN_ERR
-                                               "VFS:Filesystem thaw failed\n");
-                                       sb->s_frozen = SB_FREEZE_TRANS;
-                                       bdev->bd_fsfreeze_count++;
-                                       mutex_unlock(&bdev->bd_fsfreeze_mutex);
-                                       return error;
-                               }
-                       }
-                       sb->s_frozen = SB_UNFROZEN;
-                       smp_wmb();
-                       wake_up(&sb->s_wait_unfrozen);
-               }
-               drop_super(sb);
-       }
-
-       up(&bdev->bd_mount_sem);
-       mutex_unlock(&bdev->bd_fsfreeze_mutex);
-       return 0;
-}
-EXPORT_SYMBOL(thaw_bdev);
-
-/*
  * Various filesystems appear to want __find_get_block to be non-blocking.
  * But it's the page lock which protects the buffers.  To get around this,
  * we get exclusion from try_to_free_buffers with the blockdev mapping's
index bd7ac79..f19fd90 100644 (file)
@@ -165,15 +165,8 @@ int sync_mapping_buffers(struct address_space *mapping);
 void unmap_underlying_metadata(struct block_device *bdev, sector_t block);
 
 void mark_buffer_async_write(struct buffer_head *bh);
-void invalidate_bdev(struct block_device *);
-int sync_blockdev(struct block_device *bdev);
 void __wait_on_buffer(struct buffer_head *);
 wait_queue_head_t *bh_waitq_head(struct buffer_head *bh);
-int fsync_bdev(struct block_device *);
-struct super_block *freeze_bdev(struct block_device *);
-int thaw_bdev(struct block_device *, struct super_block *);
-int fsync_super(struct super_block *);
-int fsync_no_super(struct block_device *);
 struct buffer_head *__find_get_block(struct block_device *bdev, sector_t block,
                        unsigned size);
 struct buffer_head *__getblk(struct block_device *bdev, sector_t block,
index 5f74d61..c2c4454 100644 (file)
@@ -1874,6 +1874,13 @@ extern void bd_set_size(struct block_device *, loff_t size);
 extern void bd_forget(struct inode *inode);
 extern void bdput(struct block_device *);
 extern struct block_device *open_by_devnum(dev_t, fmode_t);
+extern void invalidate_bdev(struct block_device *);
+extern int sync_blockdev(struct block_device *bdev);
+extern struct super_block *freeze_bdev(struct block_device *);
+extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
+extern int fsync_bdev(struct block_device *);
+extern int fsync_super(struct super_block *);
+extern int fsync_no_super(struct block_device *);
 #else
 static inline void bd_forget(struct inode *inode) {}
 #endif