[PATCH] knfsd: Allow lockd to drop replies as appropriate

[pandora-kernel.git] / fs / block_dev.c

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 045f988..bc8f27c 100644 (file)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -17,11 +17,13 @@
 #include <linux/module.h>
 #include <linux/blkpg.h>
 #include <linux/buffer_head.h>
+#include <linux/writeback.h>
 #include <linux/mpage.h>
 #include <linux/mount.h>
 #include <linux/uio.h>
 #include <linux/namei.h>
 #include <asm/uaccess.h>
+#include "internal.h"
 
 struct bdev_inode {
        struct block_device bdev;
@@ -543,11 +545,11 @@ static struct kobject *bdev_get_holder(struct block_device *bdev)
                return kobject_get(bdev->bd_disk->holder_dir);
 }
 
-static void add_symlink(struct kobject *from, struct kobject *to)
+static int add_symlink(struct kobject *from, struct kobject *to)
 {
        if (!from || !to)
-               return;
-       sysfs_create_link(from, to, kobject_name(to));
+               return 0;
+       return sysfs_create_link(from, to, kobject_name(to));
 }
 
 static void del_symlink(struct kobject *from, struct kobject *to)
@@ -648,30 +650,38 @@ static void free_bd_holder(struct bd_holder *bo)
  * If there is no matching entry with @bo in @bdev->bd_holder_list,
  * add @bo to the list, create symlinks.
  *
- * Returns 1 if @bo was added to the list.
- * Returns 0 if @bo wasn't used by any reason and should be freed.
+ * Returns 0 if symlinks are created or already there.
+ * Returns -ve if something fails and @bo can be freed.
  */
 static int add_bd_holder(struct block_device *bdev, struct bd_holder *bo)
 {
        struct bd_holder *tmp;
+       int ret;
 
        if (!bo)
-               return 0;
+               return -EINVAL;
 
        list_for_each_entry(tmp, &bdev->bd_holder_list, list) {
                if (tmp->sdir == bo->sdir) {
                        tmp->count++;
+                       /* We've already done what we need to do here. */
+                       free_bd_holder(bo);
                        return 0;
                }
        }
 
        if (!bd_holder_grab_dirs(bdev, bo))
-               return 0;
+               return -EBUSY;
 
-       add_symlink(bo->sdir, bo->sdev);
-       add_symlink(bo->hdir, bo->hdev);
-       list_add_tail(&bo->list, &bdev->bd_holder_list);
-       return 1;
+       ret = add_symlink(bo->sdir, bo->sdev);
+       if (ret == 0) {
+               ret = add_symlink(bo->hdir, bo->hdev);
+               if (ret)
+                       del_symlink(bo->sdir, bo->sdev);
+       }
+       if (ret == 0)
+               list_add_tail(&bo->list, &bdev->bd_holder_list);
+       return ret;
 }
 
 /**
@@ -741,7 +751,9 @@ static int bd_claim_by_kobject(struct block_device *bdev, void *holder,
 
        mutex_lock_nested(&bdev->bd_mutex, BD_MUTEX_PARTITION);
        res = bd_claim(bdev, holder);
-       if (res || !add_bd_holder(bdev, bo))
+       if (res == 0)
+               res = add_bd_holder(bdev, bo);
+       if (res)
                free_bd_holder(bo);
        mutex_unlock(&bdev->bd_mutex);
 
@@ -1021,7 +1033,7 @@ do_open(struct block_device *bdev, struct file *file, unsigned int subclass)
                                rescan_partitions(bdev->bd_disk, bdev);
                } else {
                        mutex_lock_nested(&bdev->bd_contains->bd_mutex,
-                                         BD_MUTEX_PARTITION);
+                                         BD_MUTEX_WHOLE);
                        bdev->bd_contains->bd_part_count++;
                        mutex_unlock(&bdev->bd_contains->bd_mutex);
                }
@@ -1142,22 +1154,6 @@ static int blkdev_close(struct inode * inode, struct file * filp)
        return blkdev_put(bdev);
 }
 
-static ssize_t blkdev_file_write(struct file *file, const char __user *buf,
-                                  size_t count, loff_t *ppos)
-{
-       struct iovec local_iov = { .iov_base = (void __user *)buf, .iov_len = count };
-
-       return generic_file_write_nolock(file, &local_iov, 1, ppos);
-}
-
-static ssize_t blkdev_file_aio_write(struct kiocb *iocb, const char __user *buf,
-                                  size_t count, loff_t pos)
-{
-       struct iovec local_iov = { .iov_base = (void __user *)buf, .iov_len = count };
-
-       return generic_file_aio_write_nolock(iocb, &local_iov, 1, &iocb->ki_pos);
-}
-
 static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 {
        return blkdev_ioctl(file->f_mapping->host, file, cmd, arg);
@@ -1177,18 +1173,16 @@ const struct file_operations def_blk_fops = {
        .open           = blkdev_open,
        .release        = blkdev_close,
        .llseek         = block_llseek,
-       .read           = generic_file_read,
-       .write          = blkdev_file_write,
+       .read           = do_sync_read,
+       .write          = do_sync_write,
        .aio_read       = generic_file_aio_read,
-       .aio_write      = blkdev_file_aio_write, 
+       .aio_write      = generic_file_aio_write_nolock,
        .mmap           = generic_file_mmap,
        .fsync          = block_fsync,
        .unlocked_ioctl = block_ioctl,
 #ifdef CONFIG_COMPAT
        .compat_ioctl   = compat_blkdev_ioctl,
 #endif
-       .readv          = generic_file_readv,
-       .writev         = generic_file_write_nolock,
        .sendfile       = generic_file_sendfile,
        .splice_read    = generic_file_splice_read,
        .splice_write   = generic_file_splice_write,
@@ -1303,3 +1297,24 @@ void close_bdev_excl(struct block_device *bdev)
 }
 
 EXPORT_SYMBOL(close_bdev_excl);
+
+int __invalidate_device(struct block_device *bdev)
+{
+       struct super_block *sb = get_super(bdev);
+       int res = 0;
+
+       if (sb) {
+               /*
+                * no need to lock the super, get_super holds the
+                * read mutex so the filesystem cannot go away
+                * under us (->put_super runs with the write lock
+                * hold).
+                */
+               shrink_dcache_sb(sb);
+               res = invalidate_inodes(sb);
+               drop_super(sb);
+       }
+       invalidate_bdev(bdev, 0);
+       return res;
+}
+EXPORT_SYMBOL(__invalidate_device);