struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
- return blockdev_direct_IO_no_locking(rw, iocb, inode, I_BDEV(inode),
- iov, offset, nr_segs, blkdev_get_blocks, NULL);
+ return blockdev_direct_IO_no_locking_newtrunc(rw, iocb, inode,
+ I_BDEV(inode), iov, offset, nr_segs,
+ blkdev_get_blocks, NULL);
}
int __sync_blockdev(struct block_device *bdev, int wait)
sb = get_active_super(bdev);
if (!sb)
goto out;
- if (sb->s_flags & MS_RDONLY) {
- sb->s_frozen = SB_FREEZE_TRANS;
- up_write(&sb->s_umount);
+ error = freeze_super(sb);
+ if (error) {
+ deactivate_super(sb);
+ bdev->bd_fsfreeze_count--;
mutex_unlock(&bdev->bd_fsfreeze_mutex);
- return sb;
- }
-
- sb->s_frozen = SB_FREEZE_WRITE;
- smp_wmb();
-
- sync_filesystem(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;
- deactivate_locked_super(sb);
- bdev->bd_fsfreeze_count--;
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
- return ERR_PTR(error);
- }
+ return ERR_PTR(error);
}
- up_write(&sb->s_umount);
-
+ deactivate_super(sb);
out:
sync_blockdev(bdev);
mutex_unlock(&bdev->bd_fsfreeze_mutex);
mutex_lock(&bdev->bd_fsfreeze_mutex);
if (!bdev->bd_fsfreeze_count)
- goto out_unlock;
+ goto out;
error = 0;
if (--bdev->bd_fsfreeze_count > 0)
- goto out_unlock;
+ goto out;
if (!sb)
- goto out_unlock;
-
- BUG_ON(sb->s_bdev != bdev);
- down_write(&sb->s_umount);
- if (sb->s_flags & MS_RDONLY)
- goto out_unfrozen;
-
- 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;
- }
- }
-
-out_unfrozen:
- sb->s_frozen = SB_UNFROZEN;
- smp_wmb();
- wake_up(&sb->s_wait_unfrozen);
+ goto out;
- if (sb)
- deactivate_locked_super(sb);
-out_unlock:
+ error = thaw_super(sb);
+ if (error) {
+ bdev->bd_fsfreeze_count++;
+ mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ return error;
+ }
+out:
mutex_unlock(&bdev->bd_fsfreeze_mutex);
return 0;
}
struct page **pagep, void **fsdata)
{
*pagep = NULL;
- return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
- blkdev_get_block);
+ return block_write_begin_newtrunc(file, mapping, pos, len, flags,
+ pagep, fsdata, blkdev_get_block);
}
static int blkdev_write_end(struct file *file, struct address_space *mapping,
return retval;
}
-/*
- * Filp is never NULL; the only case when ->fsync() is called with
- * NULL first argument is nfsd_sync_dir() and that's not a directory.
- */
-
-int blkdev_fsync(struct file *filp, struct dentry *dentry, int datasync)
+int blkdev_fsync(struct file *filp, int datasync)
{
struct inode *bd_inode = filp->f_mapping->host;
struct block_device *bdev = I_BDEV(bd_inode);
* @bdev is about to be opened exclusively. Check @bdev can be opened
* exclusively and mark that an exclusive open is in progress. Each
* successful call to this function must be matched with a call to
- * either bd_claim() or bd_abort_claiming(). If this function
- * succeeds, the matching bd_claim() is guaranteed to succeed.
+ * either bd_finish_claiming() or bd_abort_claiming() (which do not
+ * fail).
+ *
+ * This function is used to gain exclusive access to the block device
+ * without actually causing other exclusive open attempts to fail. It
+ * should be used when the open sequence itself requires exclusive
+ * access but may subsequently fail.
*
* CONTEXT:
* Might sleep.
return ERR_PTR(-ENXIO);
whole = bdget_disk(disk, 0);
+ module_put(disk->fops->owner);
put_disk(disk);
if (!whole)
return ERR_PTR(-ENOMEM);
__bd_abort_claiming(whole, holder); /* releases bdev_lock */
}
+/* increment holders when we have a legitimate claim. requires bdev_lock */
+static void __bd_claim(struct block_device *bdev, struct block_device *whole,
+ void *holder)
+{
+ /* note that for a whole device bd_holders
+ * will be incremented twice, and bd_holder will
+ * be set to bd_claim before being set to holder
+ */
+ whole->bd_holders++;
+ whole->bd_holder = bd_claim;
+ bdev->bd_holders++;
+ bdev->bd_holder = holder;
+}
+
+/**
+ * bd_finish_claiming - finish claiming a block device
+ * @bdev: block device of interest (passed to bd_start_claiming())
+ * @whole: whole block device returned by bd_start_claiming()
+ * @holder: holder trying to claim @bdev
+ *
+ * Finish a claiming block started by bd_start_claiming().
+ *
+ * CONTEXT:
+ * Grabs and releases bdev_lock.
+ */
+static void bd_finish_claiming(struct block_device *bdev,
+ struct block_device *whole, void *holder)
+{
+ spin_lock(&bdev_lock);
+ BUG_ON(!bd_may_claim(bdev, whole, holder));
+ __bd_claim(bdev, whole, holder);
+ __bd_abort_claiming(whole, holder); /* not actually an abort */
+}
+
/**
* bd_claim - claim a block device
* @bdev: block device to claim
* @holder: holder trying to claim @bdev
*
- * Try to claim @bdev which must have been opened successfully. This
- * function may be called with or without preceding
- * blk_start_claiming(). In the former case, this function is always
- * successful and terminates the claiming block.
+ * Try to claim @bdev which must have been opened successfully.
*
* CONTEXT:
* Might sleep.
might_sleep();
spin_lock(&bdev_lock);
-
res = bd_prepare_to_claim(bdev, whole, holder);
- if (res == 0) {
- /* note that for a whole device bd_holders
- * will be incremented twice, and bd_holder will
- * be set to bd_claim before being set to holder
- */
- whole->bd_holders++;
- whole->bd_holder = bd_claim;
- bdev->bd_holders++;
- bdev->bd_holder = holder;
- }
-
- if (whole->bd_claiming)
- __bd_abort_claiming(whole, holder); /* releases bdev_lock */
- else
- spin_unlock(&bdev_lock);
+ if (res == 0)
+ __bd_claim(bdev, whole, holder);
+ spin_unlock(&bdev_lock);
return res;
}
if (whole) {
if (res == 0)
- BUG_ON(bd_claim(bdev, filp) != 0);
+ bd_finish_claiming(bdev, whole, filp);
else
bd_abort_claiming(whole, filp);
}
if ((mode & FMODE_WRITE) && bdev_read_only(bdev))
goto out_blkdev_put;
- BUG_ON(bd_claim(bdev, holder) != 0);
+ bd_finish_claiming(bdev, whole, holder);
return bdev;
out_blkdev_put:
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff