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| author | Christoph Hellwig <hch@infradead.org> | 2014-02-10 10:27:11 +1100 |
|---|---|---|
| committer | Dave Chinner <david@fromorbit.com> | 2014-02-10 10:27:11 +1100 |
| commit | 6039257378e4c84da06e68230b14fef955508ce6 (patch) | |
| tree | 87f5681b75c36d4b6d395f92a82ffe7b1b1dde5a | |
| parent | 38dbfb59d1175ef458d006556061adeaa8751b72 (diff) | |
| download | kernel_replicant_linux-6039257378e4c84da06e68230b14fef955508ce6.tar.gz kernel_replicant_linux-6039257378e4c84da06e68230b14fef955508ce6.tar.bz2 kernel_replicant_linux-6039257378e4c84da06e68230b14fef955508ce6.zip | |
direct-io: add flag to allow aio writes beyond i_size
Some filesystems can handle direct I/O writes beyond i_size safely,
so allow them to opt into receiving them.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
| -rw-r--r-- | fs/direct-io.c | 18 | ||||
| -rw-r--r-- | include/linux/fs.h | 3 |
2 files changed, 15 insertions, 6 deletions
diff --git a/fs/direct-io.c b/fs/direct-io.c index 160a5489a939..a701752dd750 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -1194,13 +1194,19 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, } /* - * For file extending writes updating i_size before data - * writeouts complete can expose uninitialized blocks. So - * even for AIO, we need to wait for i/o to complete before - * returning in this case. + * For file extending writes updating i_size before data writeouts + * complete can expose uninitialized blocks in dumb filesystems. + * In that case we need to wait for I/O completion even if asked + * for an asynchronous write. */ - dio->is_async = !is_sync_kiocb(iocb) && !((rw & WRITE) && - (end > i_size_read(inode))); + if (is_sync_kiocb(iocb)) + dio->is_async = false; + else if (!(dio->flags & DIO_ASYNC_EXTEND) && + (rw & WRITE) && end > i_size_read(inode)) + dio->is_async = false; + else + dio->is_async = true; + dio->inode = inode; dio->rw = rw; diff --git a/include/linux/fs.h b/include/linux/fs.h index 09f553c59813..f7faefcf4843 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2527,6 +2527,9 @@ enum { /* filesystem does not support filling holes */ DIO_SKIP_HOLES = 0x02, + + /* filesystem can handle aio writes beyond i_size */ + DIO_ASYNC_EXTEND = 0x04, }; void dio_end_io(struct bio *bio, int error); |