raw: fsync method is now required

Commit 148f948ba877f4d3cdef036b1ff6d9f68986706a (vfs: Introduce new
helpers for syncing after writing to O_SYNC file or IS_SYNC inode) broke
the raw driver.

We now call through generic_file_aio_write -> generic_write_sync ->
vfs_fsync_range.  vfs_fsync_range has:

        if (!fop || !fop->fsync) {
                ret = -EINVAL;
                goto out;
        }

But drivers/char/raw.c doesn't set an fsync method.

We have two options: fix it or remove the raw driver completely.  I'm
happy to do either, the fact this has been broken for so long suggests it
is rarely used.

The patch below adds an fsync method to the raw driver.  My knowledge of
the block layer is pretty sketchy so this could do with a once over.

If we instead decide to remove the raw driver, this patch might still be
useful as a backport to 2.6.33 and 2.6.32.

Signed-off-by: Anton Blanchard <anton@samba.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <jens.axboe@oracle.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Tested-by: Jeff Moyer <jmoyer@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/char/raw.c b/drivers/char/raw.c
index d331c59b571c5c2520787e8a753062a91e2ef22c..f5a32317b751ef4de691c42407bdac85c7bbecb0 100644 (file)
--- a/drivers/char/raw.c
+++ b/drivers/char/raw.c
@@ -248,6 +248,7 @@ static const struct file_operations raw_fops = {
        .aio_read =     generic_file_aio_read,
        .write  =       do_sync_write,
        .aio_write =    blkdev_aio_write,
+       .fsync  =       block_fsync,
        .open   =       raw_open,
        .release=       raw_release,
        .ioctl  =       raw_ioctl,

diff --git a/fs/block_dev.c b/fs/block_dev.c
index d11d0289f3d24bf9489acba6059c5d8ada9eda52..8db62b2b6df8ad4522ab49e1e1c4a0408236b2c4 100644 (file)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -404,7 +404,7 @@ static loff_t block_llseek(struct file *file, loff_t offset, int origin)
  *     NULL first argument is nfsd_sync_dir() and that's not a directory.
  */
  
-static int block_fsync(struct file *filp, struct dentry *dentry, int datasync)
+int block_fsync(struct file *filp, struct dentry *dentry, int datasync)
 {
        struct block_device *bdev = I_BDEV(filp->f_mapping->host);
        int error;
@@ -418,6 +418,7 @@ static int block_fsync(struct file *filp, struct dentry *dentry, int datasync)
                error = 0;
        return error;
 }
+EXPORT_SYMBOL(block_fsync);
 
 /*
  * pseudo-fs

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 10b8dedcd18b82a82491129a2baaef0f18ca4ce1..5d9c7e27c5a43b2c5902a89966ebb57ced16dc7b 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2212,6 +2212,7 @@ extern int generic_segment_checks(const struct iovec *iov,
 /* fs/block_dev.c */
 extern ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
                                unsigned long nr_segs, loff_t pos);
+extern int block_fsync(struct file *filp, struct dentry *dentry, int datasync);
 
 /* fs/splice.c */
 extern ssize_t generic_file_splice_read(struct file *, loff_t *,